Objective. To determine and describe the pathophysiological aspects of oropharyngeal swallowing in patients with Parkinson's disease more accurately, a pilot study of qualitative as well as quantitative parameters of swallowing was performed using videofluoroscopy (VFS). Methods. Ten patients with a diagnosis of idiopathic Parkinson's disease having dysphagic complaints and ten healthy age- and gender-matched control subjects underwent a standardized videofluoroscopic swallowing protocol. Information on the swallowing function was derived from temporal, spatial, and descriptive visuoperceptual parameters. Intra- and interrater reliability was calculated. Results. No significant differences were found between Parkinson patients and healthy control subjects for the majority of the reliable variables. Conclusions. It was concluded that swallowing function seemed to be preserved in the early stages of Parkinson's disease. Furthermore, the reliability of many quantitative as well as qualitative swallowing parameters proved insufficient, raising questions about the interpretation of study outcomes in videofluoroscopy. Dysphagia is a common symptom of Parkinson's disease . In 75–1The purpose of this study is twofold: to determine the reliability of timed as well as spatial parameters in videofluoroscopy of swallowing necessary to interpret the study outcome and to determine the differences in swallowing function between patients with Parkinson's disease and healthy control subjects, matched for age and gender. Qualitative assessment of swallows was based on visuoperceptual evaluation of videofluoroscopic signs by an expert panel, whereas quantitative assessment was obtained by means of a specialized computer software application that allowed capturing and digitizing frames in videofluoroscopic recordings. Using the manual input of anatomical references determined by an expert panel, parameters could be measured. Patients with idiopathic Parkinson's disease (diagnosed by a neurologist) having subjective clinical complaints of dysphagia were recruited from several neurological departments in the Netherlands. All patients reported dysphagic complaints ranging from mild to severe, for example, these included slow eating, oral or pharyngeal passage disorder, coughing while drinking, and a diminished quality of life as a direct consequence of dysphagia. None of them suffered from any neurological disease except Parkinson's. All patients were able to perform a swallow. Other exclusion criteria were deep brain stimulation (DBS), a Mini Mental State Examination (MMSE) score below 23, severe dyskinesia of head and neck (resulting in problems with VFS recording), mental depression, head and neck cancer, severe cardiopulmological disease, speech therapy during the past six months, or surgery of the swallowing mechanism or the central nervous system . All patAll patients underwent a detailed clinical examination by an experienced laryngologist and a speech and language pathologist. Before the VFS examination the presence and severity of dysphagia were assessed using the Functional Oral Intake Scale (FOIS) and a fiberoptic endoscopic evaluation of swallowing (FEES) , 14. FolSwallows were analyzed using a specific software application  to capture, digitize, and measure the videofluoroscopic swallowing sequences . All varQuantitative measurements were determined for each swallow by two experienced raters with extensive training in the analysis of VFS studies of normal and disordered swallowing. Kahrilas et al. used more physiologic references to calculate timed variables in contrast with fixed anatomical landmarks, like the point where the mandible crosses the tongue base . In thisy-axis was defined by the anterior/inferior corner of the third and fifth cervical vertebral bodies. The x-axis crosses the y-axis at the anterior/inferior corner of the third vertebral body. By marking these reference points in each frame, movements of the subject in any plane were corrected  and swallow trials were scored in randomized order. The consensus training in visuoperceptual evaluation was accompanied by a manual including strict, well-defined guidelines to rate these ordinal variables. The exact interpretation per level of each of the three or five point scales was trained during five separate sessions with intervals of one week. During these intervals the expert raters had to accomplish test trials separately that were discussed the next session. To obtain the intrarater reliability each rater performed repeated measurements of all temporal, spatial, and visuoperceptual variables in all swallows within a period of two weeks. U test  or the Chi-Square test . All statistical analyses were performed using SPSS version 16.0 for Windows . Statistical analysis was conducted stepwise. First, Intraclass Correlation Coefficients (ICC) and Cronbach's alphas (>0.65) were computed for all quantitative parameters to determine the reliability and the degree of intra- and interrater (absolute) agreement. For all ordinal parameters Cohen's Kappa index of agreement was used. Second, for each reliable temporal, spatial, and visuoperceptual variable, group comparisons were performed over the averaged data of the expert raters. Differences between the Parkinson and the healthy control populations were tested for significance by means of the Mann-Whitney Ten mentally competent dysphagic patients  with a diagnosis of idiopathic Parkinson's disease were included. The H&Y staging scale ranged from mild to moderate (median II). In Tables U test, no significant differences were found regarding the spatial variables. The Chi-Square test did not reveal significant group differences for the visuoperceptual variables. The temporal variable VPJc showed a significant difference between the two groups. Patients with Parkinson's disease showed a significantly delayed velopharyngeal junction closure compared to healthy controls. Tables Before interpreting the present study outcome, the intrarater and interrater reliability was determined. Despite the thorough consensus training using well-defined guidelines as well as the strict methodological protocol for repeated measurements by the expert raters to calculate the intra- and interrater reliability in the present study poor reliability was observed for several parameters. Diverse situations may have contributed to this finding. First, despite their high expertise, the raters may have lacked consensus on a definition of, for example, delayed initiation of the pharyngeal reflex or maximum horizontal (anterior) hyoid motion. Second, patients were found to be rather homogeneous with respect to several of the variables being measured; that is, some of them, such as preswallow anterior spill and preswallow posterior spill, always scored zero. Finally, it cannot be excluded that the lack of internal consistency may have resulted from the nature of the measurement scales and/or instruments; for instance, visuoperceptual variables were scored on three or five point scales. As worldwide no strict guidelines exist, some scope for subjectivity was left to the rater in the discrimination of these ordinal variables. Consequently, these variables were less reliable compared to the temporal or spatial variables that were defined frame by frame using specific software . This soDespite the presence of a disturbed swallow physiology in Parkinson patients, few significant differences were found between the two pilot groups. Velopharyngeal junction closure (VPJc) was different, being significantly delayed in the Parkinson group. The remaining temporal, spatial, or visuoperceptual variables did not show significant differences or tendencies between the groups. The lack of significant group differences can be the result of the nature and sensitivity of the assessment tool (VFS). As described in the study of Ertekin et al. conflicting results obtained from radiological and manometric studies in Parkinson patients were found . Also noIn order to design therapy effect studies for dysphagia in Parkinson's disease, it is necessary to understand the pathophysiology of swallowing in this patient group. In previous studies, several authors investigated pathological mechanisms of oral-pharyngeal dysphagia in Parkinson patients , 19. SevN = 60 swallows in total) thirty variables were assessed, resulting in 1800 measurements. The selection of parameters in follow-up studies should be based on sufficient intra- and interrater reliability as well as on a patient data distribution using the full range of the parameters' scale. The literature on swallowing assessment usually provides only limited information on the definitions of the parameters being used, the exact description of the protocol applied during videofluoroscopy, the number of raters or the explanation of the concept of an “expert” or “experienced” rater, the intra- and interrater reliability, and the effect of training on reliability coefficients. Interpretation of any study outcome lacking such information may be hazardous. Dysphagic Parkinson patients could potentially benefit from improved diagnostic swallowing assessment by implementing well-defined videofluoroscopic parameters with sufficient intra- and interrater reliability.In this pilot study, few restrictions were placed on the kind and number of parameters to use. Per swallow  was found, particularly for the visuoperceptual variables. The reliable variables could only reveal very few significant differences between both pilot groups. Swallowing seems relatively preserved in the early stages of Parkinson's disease. Recommendations for future research on pathophysiological aspects of swallowing in Parkinson's disease may include study designs with larger numbers of dysphagic patients and healthy control subjects. It may be interesting too to include patients with a more severe degree of Parkinson's disease  to determine differences between such a patient population and the patients who visit speech therapists as described in this study. The present study has found relatively low intrarater and interrater reliability for many of the variables used despite thorough training and high level of the raters' expertise. In the literature, information on reliability is usually lacking. After training, raters should have maximum consensus about the exact definition of the variables included and be familiar with the rating scales being used as well as with their levels, preferably anchored in detailed descriptions. Any swallowing study should provide information on training and the intrarater and the interrater reliability in order to allow accurate interpretation of the study outcome. Maybe the suggestion that data described in earlier studies may lack sufficient reliability and, therefore, may not be useful in determining therapy outcome, has been rather unexpected. Still, the problems with reliability in outcome studies such as described in this paper may also be the most interesting as well as the most important finding. Newly developed research will need to take this issue into account so that in the near future, in research on the physiology of swallowing in Parkinson's disease, the complementary benefits of using qualitative as well as quantitative variables in videofluoroscopy can be studied more thoroughly.


PLOS Biology, Lucia Prieto-Godino of the University of Cambridge and her collaborators report the results of the first systematic investigation of how the olfactory network assembles in fruit fly embryos. They found that the activity of OSNs is crucial for the proper formation of connections in the olfactory system during these early stages of development. The findings reveal surprising similarities between vertebrates and insect embryos in the formation of olfactory networks.This week in Specifically, they found that projection neurons in the glomeruli of fruit fly embryos only formed extensions that would eventually connect with other neurons after being contacted by OSNs, unlike the pattern seen in adult fruit flies. Projection neurons were more likely to survive when they were contacted by OSNs, and the activity of OSNs controlled the growth of extensions formed by projection neurons.OSN activity also controlled how OSNs formed connections with cells in glomeruli. When the researchers genetically silenced OSN activity, they found that the OSNs formed connections that extended across a broader-than-normal swath of glomeruli, similar to previous findings in vertebrates. This suggests that OSN activity is crucial for the normal wiring of the olfactory network.The study reveals new insights into the development of the olfactory network in insect embryos and shows that OSN activity plays a key role in guiding the development of the olfactory circuitry. Surprisingly, these patterns resemble those observed in vertebrates, but not adult fruit flies. Because neural circuits in other sensory and motor systems share similar properties, the findings may represent general mechanisms that underlie the development of networks in the nervous system.Prieto-Godino LL, Diegelmann S, Bate M (2012) Embryonic Origin of Olfactory Circuitry in Drosophila: Contact and Activity-Mediated Interactions Pattern Connectivity in the Antennal Lobe. doi:10.1371/journal.pbio.1001400


Drosophila is a powerful genetic model system for investigating neuronal function. Several important membrane ion channel genes, such as voltage-gated sodium and potassium channels, were first identified and isolated in the fruit fly. Technical advances in experimental methods have recently made possible direct electrophysiological recording of ionic currents in central neurons, allowing the genetic advantages of this system to be applied to analysis of cellular and circuit function and homeostasis.Drosophila neurons [Drosophila  and may be the underlying cause of the increase of the persistent component of the sodium current [. Because of experimental limitations, computational modeling is essential for understanding the functional implications of this change.An important open question is the functional effect of channel splice variants, which have recently been found in  neurons . The com current . BecauseWe previously presented a computational approach to determine the full set of biophysical parameters of the sodium channel splice variants . We thenIn the present work, we improve this model neuron by including morphological details. We take the morphological information from identified larval aCC abdominal dorsomedial motoneurons, which innervate the dorsal muscles . A two-c


Cellular ATP levels are generated by glucose-stimulated mitochondrial metabolism and determine metabolic responses, such as glucose-stimulated insulin secretion (GSIS) from the β-cells of pancreatic islets. We describe an analysis of the evolutionary processes affecting the core enzymes involved in glucose-stimulated insulin secretion in mammals. The proteins involved in this system belong to ancient enzymatic pathways: glycolysis, the TCA cycle and oxidative phosphorylation.We identify two sets of proteins, or protein coalitions, in this group of 77 enzymes with distinct evolutionary patterns. Members of the glycolysis, TCA cycle, metabolite transport, pyruvate and NADH shuttles have low rates of protein sequence evolution, as inferred from a human-mouse comparison, and relatively high rates of evolutionary gene duplication. Respiratory chain and glutathione pathway proteins evolve faster, exhibiting lower rates of gene duplication. A small number of proteins in the system evolve significantly faster than co-pathway members and may serve as rapidly evolving adapters, linking groups of co-evolving genes.Our results provide insights into the evolution of the involved proteins. We find evidence for two coalitions of proteins and the role of co-adaptation in protein evolution is identified and could be used in future research within a functional context. Eukaryotic organisms make use of complex biochemical pathways to maintain homeostatic processes in response to changes in their environment. These responses can be broadly divided into gene regulatory responses, whereby changes in an environmental condition give rise to changes in gene expression, and metabolic responses, which result from the responses of metabolic networks to environmental changes. Many metabolic adaptations to environmental changes are mediated by genetic regulation.Pancreatic β-cells are the cells responsible for insulin secretion in vertebrates and therefore play a key role in glucose homeostasis. It has been suggested that glucose homeostasis evolved to protect brains from hypo- and hyperglycaemic effects . HoweverGlucose-stimulated insulin secretion (GSIS) from the β-cells of pancreatic islets is a metabolic response that is critically dependent on cellular ATP levels generated by glucose-stimulated mitochondrial metabolism. In pancreatic β-cells, ATP production is proportional to glucose uptake by the cell, which in turn is proportional to the glucose concentration in the surrounding body fluids . A complThere have been evolutionary studies of certain individual components of the GSIS system. Phylogenetic analysis of metabolic evolution ,9 suggesNumerous forces can act on the evolution of metabolic pathways such as the GSIS network, including pressures affecting evolutionary rate in a systematic manner, gene duplication, positive and purifying selection, or gene expression . AdditioThe 48 reactions identified in the GSIS model of core pancreatic β-cell biochemistry are catalysed by a minimum of 77 protein components based on current biochemical knowledge [To characterise the evolutionary dynamics of the GSIS system, we first considered the antiquity of the individual genes that comprise it. Antiquity is defined as the taxonomic distance over which homologues of the mammalian genes could be detected searching the COGENT database . Using tThe construction of phylogenetic profiles also allowed the identification of human proteins that share homologues in other genomes, indicating a history of ancient gene duplication. This analysis identified six protein clusters. The largest of these comprised the four isocitrate dehydrogenases , which shared 31 homologues in other genomes. Other groups also consisted of functionally related proteins: pyruvate dehydrogenase complex subunits , other dehydrogenases , and superoxide dismutases . Two weaker linkages were also detected between less obviously related proteins: ETF:Q oxidoreductase (ETF-QO) and glutathione reductase (GSSGR) (7 shared homologues) and pyruvate dehydrogenase subunit B (PDCb) and cytochrome c oxidase subunit 5A (Cox5A) (2 shared homologues). Searches of the Pfam database  identifiThe preceding analysis indicates that a high proportion of GSIS proteins have been conserved over long periods of evolutionary time. We therefore investigated whether this was reflected in their level of sequence conservation. We did this by measuring conservation between human and mouse orthologues, as a proxy for the overall level of evolutionary conservation. We used this pair of species because of the quality of their genome sequences and because their divergence time (c. 90 MYA) is short enough that they will show relatively little mutational saturation. Of 77 enzyme genes for which we searched for human and mouse orthologues, we could identify 69 orthologue pairs in the two species. As mentioned, the missing genes primarily reflect absence of knowledge of the identity of some membrane transporters in the system .We determined sequence similarity between these orthologs at the protein level, as this is the most relevant measure for identifying functional conservation. Individual values for protein sequence similarity for each enzyme are presented in Table To further characterise the distribution of conservation across the identifiable sub-pathways and phylogenetic categories in the model we carried out an analysis of variance (ANOVA). Of five treatment variables , only sub-pathway membership had a significant effect on divergence . A Tukey HSD test showed significantly lower sequence conservation (adjusted P < 0.05) for glutathione pathway and respiratory chain proteins than for members of the glycolysis and TCA cycle groups. The glutathione pathway proteins also showed significantly lower conservation than the pyruvate and NADH shuttle proteins. Taken together, these results suggest that there are two clusters of conservation level in the data set - on the one hand glycolysis, metabolite transport, TCA cycle and pyruvate/NADH shuttles and on the other hand the respiratory chain and the glutathione pathway. This distinction is illustrated in the Tukey's boxplot Figure , which sThe cluster diagram in Figure After duplication, genes appear to continue to undergo purifying selection with their evolutionary rates and genomic persistence depending on their level of essentiality . However24 of the genes analysed here are associated with Mendelian diseases in the OMIM database Table . We founThis study reveals a highly significant relationship between pathway membership and human-mouse divergence in the GSIS system. The analysis indicated two cross-pathway clusters of divergence - a higher conservation cluster spanning glycolysis, the TCA cycle plus metabolite transport and the components of the NADH shuttle and pyruvate cycle, and a lower conservation cluster comprising respiratory chain proteins and components of the glutathione pathway. All the genes considered, with the exceptions of the mitochondrially encoded Cox1 and Cox2 in Complex IV of the respiratory chain, are encoded by the nuclear genome, so a genome effect did not play a role in this result. It should be noted that, as we have considered protein similarity in these analyses, they cannot be used to directly infer differences of evolutionary rate at the DNA level as they also include the influence of selection on protein sequences.The results are consistent with those of Vinogradov , who shoWe also observed a second, weaker coevolutionary pattern than that of gene divergence within pathways. This was of evolutionary duplication within at least some of the pathways. Gene duplication is a classic mechanism of gene diversification which can be followed by functional diversification processes such as subfunctionalisation, neofunctionalisation and microfunctionalisation -27. ThusGAPD showed very high frequencies of gene duplication throughout its recent evolutionary history, leading to it being an outlier in Figure Gene duplication is usually considered to be followed by a period of relaxed selection followed by the continuation of a regime of purifying selection . The co-These observations present us with two opposing views of the evolution of GSIS proteins: high conservation of core biochemical pathways with higher divergence of the respiratory chain, but also restricted duplication of respiratory chain genes compared to core biochemistry proteins, especially glycolytic enzymes which show the highest conservation. A correlation analysis showed a significant negative correlation between evolutionary divergence and numbers of gene duplications, although this only accounted for 11% of variance.It has been suggested that "older" genes tend to evolve more slowly than "younger" ones  and therUnlike Vinogradov , we did It has been suggested that disease genes tend to be "ancient" . Of the + and CoA. The IDHcp intersection is less clear, but is one step in linking the TCA cycle to glycolysis, and appears to be involved in regulating the pyruvate-malate equilibrium in the cytosol. SOD2e is at a key step in the detoxification of reactive oxygen species generated by the respiratory chain and creates the intersection with the glutathione pathway by converting O2- to H2O2.Although the main feature of Figure Taken together, the picture we obtain from these analyses is that the GSIS system consists of two evolutionary coalitions, each evolving in a concerted manner. The soluble enzymes carrying out core metabolic processes, particularly glycolysis and the TCA cycle, evolve slowly at the sequence level but undergo a relatively high rate of gene duplication compared to the respiratory chain and glutathione pathway proteins, which evolve more rapidly but undergo relatively little gene duplication. The glycolysis pathway, although highly conserved at the sequence level, displays a wider range of duplication histories than other pathways. Steinke et al  analysedAlthough our sample of positive selection may be biased, most positive selection episodes appear to have taken place in respiratory chain genes. The reason for the more rapid evolution of the respiratory chain genes is unknown, but it is worth noting that most of the proteins here are nuclearly encoded proteins involved in the regulation of the function of the respiratory chain . It may Most of the functions of the component pathways of the GSIS network seem likely to have been conserved during evolution. Despite this the system has accommodated changes through sequence evolution and gene duplication. While it will require more extensive functional analysis to characterise the pressures driving the evolution of this system, it appears that these pressures have been accommodated in different ways by different parts of the system, as detailed above.The GSIS system consists of two evolutionary coalitions, each evolving in a concerted manner. The soluble enzymes carrying out core metabolic processes evolve slowly at the sequence level but undergo a relatively high rate of gene duplication compared to the respiratory chain and glutathione pathway proteins, which evolve more rapidly but undergo relatively little gene duplication. A small number of rapidly evolving proteins may represent evolutionary adapters, which mediate the different evolutionary trajectories of the different sub-pathways.The comparative analysis of the GSIS network provides key insights into the evolution of the involved proteins that might be used in future research within a functional context, by simulating the function of the entire network in health and disease . ElementThe analysis is based on the components of a mathematical model of the core biochemistry of mouse glucose-stimulated insulin secretion published previously , consistPhylogenetic profiles  of humandist and hclust functions and Euclidian distances [Gene trees obtained from Ensembl were screened visually for duplication events and used to construct duplication vectors for each gene. These vectors consisted of the number of duplications falling at nodes labelled with particular times and taxon names in Ensembl . Vectors were only extended to the point at which a duplication created a new gene family, to avoid confusion with selective forces acting on proteins with different functions, and non-vertebrate duplications were excluded. Vectors were subjected to hierarchical clustering using the R istances . EuclidiLineages showing evidence of positive selection were identified from the Selectome database  and confCA and JMH designed the research and outlined the manuscript. CA, MS, SF, OE and LH performed the computational analysis. CA, MS, LH and JMH interpreted the data. ST and CAO provided feedback on the results and contributed in drafting the manuscript. CA and JMH wrote the paper. All authors read and approved the final manuscript.Overview of the GSIS network. Reactions are represented as arrows  and labelled in green v1 to v53 according to [rding to  which alClick here for file


The precise regulation of gene transcription during metazoan development is controlled by a complex system of interactions between transcription factors, histone modifications and modifying enzymes and chromatin conformation. Developments in chromosome conformation capture technologies have revealed that interactions between regions of chromatin are pervasive and highly cell-type specific. The movement of enhancers and promoters in and out of higher-order chromatin structures within the nucleus are associated with changes in expression and histone modifications. However, the factors responsible for mediating these changes and determining enhancer:promoter specificity are still not completely known. In this review, we summarize what is known about the patterns of epigenetic and chromatin features characteristic of elements involved in long-range interactions. In addition, we review the insights into both local and global patterns of chromatin interactions that have been revealed by the latest experimental and computational methods. Gene regulation during differentiation and development is responsible for the precise coordination of processes, which determine cell fate and how the anatomical plan develops . ResearcThe various types of regulatory elements in the genome integrate and interpret information from a multitude of regulatory signals to tightly control the spatiotemporal expression of important developmental factors . Some geIn this review, we give an overview of the current knowledge regarding regulatory elements involved in regulating gene expression, and how these elements communicate with each other during metazoan development. We discuss how the system of interactions between transcription factors (TFs), histone modifications and the 3D organization of chromatin result in the ability to generate complex spatiotemporal expression patterns.A promoter is the genomic region overlapping the transcription start sites (TSSs) of a gene. Because of the precision with which TSSs can be identified, especially using CAGE technology , this clThe architecture of a gene’s promoter relates to both the function of the gene and how it is regulated. It has been proposed that there are at least three main functional classes of PolII promoters in metazoa . Type I The regulatory content and architecture of the promoters is insufficient for explaining the diversity observed in gene expression patterns, especially the complex patterns of genes whose products are master regulators of development and differentiation. Most of the regulatory content of a metazoan genome lies outside of proximal promoters ; enhancecis-regulatory elements have found that the arrangement of TFBSs can be classified into one of three distinct architectures (Based on the existence of cooperativity between bound TFs and the spacing and order of TFBS within an enhancer (often referred to as an enhancer grammar), studies of tectures . The enhtectures  architectectures , TFs aretectures . This mospa) enhancer of Pax2 in Drosophila  within the nucleus. In mammalian cells, there is evidence that the relative position of a gene locus within its CT influences its ability to form either interior . Alteratm its CT . Within m its CT ,121. Them its CT ], which m its CT . In somem its CT . The movDrosophila genome consists of multi-gene chromatin domains, which can be large and include dozens of genes  have been found to be in contact with the nuclear lamina  Figure . These losophila . The hunStudies have shown that Polycomb and H3K27me3 can form continuous chromatin domains, which can be larger than 100 kb and show overlap with silenced genes and intergenic regions . These dThe mechanisms that modulate long-range interactions are currently poorly understood. Factors such as CTCF, cohesin, mediator and small RNAs  seem to Regulatory elements referred to as insulators are able to block communication between enhancers and their cognate promoter. These elements are thought to function by blocking enhancer:promoter interactions , either et al.  located at the 5′ section of the HOXA locus  seems to work by activating their neighbouring gene in cis. A number of these ncRNAs seem to bind with mediator, resulting in the expression of their target genes  are important in mediating enhancer:promoter interactions. XA locus , which iet genes . Depletiet al.  and chromosome conformation capture methods. By tagging specific sequences with fluorescent probes, FISH allows the identification of regions of the genome that are brought into close spatial proximity  result in the loss of interactions between the gene and its enhancers, leading to loss of the overall hub-like structure  that are important for controlling DNA transcription . By applet al.  were ablHi-C has enabled the calculation of the probability that two randomly chosen loci interact . This coet al. -α was used as bait to identify interactions between regions of the genome, which it was mediating . As expeet al.  used Pol , when they have been found to interact. A large connected component (containing ∼40% of the elements involved) has been identified within the network of PolII-mediated chromatin interactions . This neThe identification of the different factors and histone modifications involved in long-range regulation will help elucidate how specific enhancers target specific promoters without binding to intervening promoters.It does not seem that there are any features specific to enhancers involved in long-range regulation compared with those involved with regulation over shorter distances. Indeed, it seems that the ability to respond to long-range interactions depends on the promoter architecture of a gene and the state of intervening insulators. The development of new genome-wide techniques has provided a way to systematically identify regions that are targeted by specific proteins and co-localize in nuclear space. The results from ChIP-seq and chromosome conformation capture assays are, however, averaged over a cell population, and they do not provide any information on the temporal dynamics and cell-to-cell variation of long-range interactions. Improvements in the temporal resolution of experiment techniques should help determine how chromatin moves during the cell cycle and how this affects and which genes are upregulated and downregulated at specific stages. Studies of long-range interactions are also limited by the relatively low resolution of Hi-C. As this improves, we expect that new findings will follow regarding the global patterns of interactions between individual regulatory elements. Examination of this in multiple cell types and species will enable us to understand how the constraints on 3D conformation affect the arrangement and conservation of regulatory elements.


A 22-month-old child presents with craniosynostosis and the pictured limb deformities.What is the most likely diagnosis and what is its etiology?Describe repair of the cranial deformity.What other procedures may be necessary for this child?Syndromic craniosynostosis such as Crouzon, Apert, Pfeiffer, Saethre-Chotzen, and Carpenter syndromes are represented by a common set of calvarial, midface, and hand deformities. The syndactyly in this case makes the diagnosis of Apert syndrome  most likely. Other physical features include craniosynostosis, hypertelorism, and midface hypoplasia. Defects in the fibroblast growth receptor 2 gene on chromosome 10 and the fibroblast growth receptor 3 gene on chromosome 4 have been implicated. It is inherited in an autosomal dominant fashion, but most cases involve sporadic mutations. Approximately 50% of children born with Apert syndrome experience mild to moderate mental retardation.Surgical repair of the cranial deformities involves cranial vault expansion and fronto-orbital advancement to reduce the exophthalmos as well as reduce intracranial pressure. This procedure is performed prior to 1 year of age to maximize the reparative abilities of the calvarium and to reduce the reported incidence of cognitive delays.The limb abnormalities warrant extensive reconstruction and present the surgeon with one of the most complex congenital limb deformities. Return of rudimentary function can be expected following a multistage reconstruction. The most important procedure is the opening of the first and fourth web spaces.


Root canal anatomy diversity and aberrations are common especially in permanent dentition. A thorough understanding of the basic root canal anatomy and its diversities are necessary for successful endodontic treatment. Mandibular second premolars are usually single-rooted and have one root canal. Incidence of three separate root canals in this tooth is quite rare and taurodontism with three separate canals has never been reported in literature so far. The use of cone-beam computed tomography scan in this rare case greatly contributed to making a confirmatory diagnosis and successful nonsurgical endodontic management thereafter. A proper understanding of the anatomy of root canal system is absolutely necessary for successful endodontic treatment , 2. The Dental anomalies constitute great part of tooth morphology variations; one of the most important abnormalities in tooth morphology is taurodontism.Taurodontism can be defined as a change in tooth shape caused by the failure of Hertwig’s epithelial sheath diaphragm to invaginate at the proper horizontal level. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cementoenamel junction are the characteristic features. The wide range of variability of prevalence [from less than 0.1% to 48%] is most likely because of different diagnostic criteria and racial variations .Literature reviews of this subject reveal wide variations and diversities in the root canal morphology of mandibular premolars.Among different studies carried out on aberrations of root canal system -9, ZilliRodig and Hulsmann reported Suchdeva et al. have concluded that the occurrence of four separate roots with four distinct root canals in the mandibular second premolars has never been reported in the literature . VujaskoThis rare case report presents successful nonsurgical endodontic treatment of a taurodont mandibular right second premolar with three separate root canals, wherein cone-beam computed tomography (CBCT) was used as a confirmatory diagnostic tool.A 23-year-old male patient referred to our office with a chief complaint of intermittent pain in relation to their premolar tooth (mandibular right second premolar) for approximatgely 3-months. The patient also complained of episodes of sensitivity to hot and cold food in the involved tooth. Medical history was noncontributory.Clinical examination revealed moderate oral hygiene; also there was a temporary filling in tooth #29, with secondary caries around the margins. There was no evidence of either swelling or sinus tracts. The involved tooth was tender to percussion. No periodontal pockets were present. Radiographic evaluation of the involved tooth revealed an unusual, complex root canal anatomy. Vague outlines of two roots with taurodontism could be identified. There was widening of the periodontal ligament space with periapical radiolucency around the distal root of tooth #29. In the panoramic radiography, the same condition was observed on tooth #20. In addition, the peg-shaped tooth #7  and bilateral three-root mandibular first molars were seen .Based on clinical and periapical radiographic findings, the patient was referred to an oral and maxillofacial radiologist for a cone-beam computed tomography. Informed consent was obtained from the patient and a CBCT of the mandible was performed by using the Promax3D . A three-dimensional image of the mandible was obtained. The involved tooth was focused, and the morphology was obtained in transverse, axial, and sagittal sections with a thickness of 0.48 mm, along with three-dimensional reconstructed images.The axial images of CBCT revealed other variations such as third canals in taurodont premolars and second canals in all mandibular anterior teeth .Subsequent to the confirmatory diagnosis, a treatment plan was prepared for the involved tooth. After local anesthesia was administered, a rubber dam was used to isolate the tooth. The defective restoration and secondary caries were removed. The access opening was modified with great attention to the approximate locations of the orifices of the three root canals.On careful inspection of the pulp chamber floor, three separateroot canal orifices were detected . Coronal flaring of all the three canals was carried out with Gates Glidden drills and working length was determined using an apex locator , which was later confirmed by a radiograph .The canals were cleaned and shaped up to ISO #35 master apical file under copious irrigation with 2.5% sodium hypochlorite and 17% EDTA. The root canals were dried with sterile paper points  and filled with calcium hydroxide paste ; then, access cavity was temporarily sealed with Cavit . The patient was scheduled for one-week follow up. The tooth was completely asymptomatic at this follow-up. Calcium hydroxide paste was removed, and the roots canals were obturated by cold lateral compaction of gutta-percha using AH26 sealer . A postoperative radiograph was taken , and theDiagnosis and management of extra roots and root canals in mandibular premolars is one of challenges in endodontics -29. TherRadiographs yield two-dimensional images of three-dimensional objects, resulting in superimposition of images. Therefore, they are of rather limited use and value in complex root canal anatomy Cases.Interpretation based on a two-dimensional radiograph may alert the clinician to the presence of aberrant anatomy but cannot fully show the morphological structure of root canals and their interrelations . Based oThe CBCT images in this study revealed two separate taurodont roots  with three distinct root canals. Each of the root canals had separate apical orifice. Although the vague outlines of the two roots could be observed on the radiograph, the confirmatory diagnosis of the three root canals , third canal of mandibular left second premolar and also second canals of all mandibular anterior teeth could only be made with the help of CBCT.Clearly, these findings are clinically important as in a study at the University of Washington assessing the results of endodontic therapy, in which the mandibular first and second premolars showed failure rates of 11.45% and 4.54% . ConceivDuring root canal treatment of taurodont teeth, the clinician should appreciate the complexity of the root canal system, canal obliteration and configuration, and the potential for extra roots and canals. Careful exploration of the grooves between all the orifices, particularly with magnification, use of ultrasonic irrigation, and a modified filling technique are particularly important .Successful nonsurgical endodontic treatment of a taurodont mandibular second premolar with three separate root canals was presented. In this case, the presence of a third root canal in a taurodont tooth and also other variations in the root canal system were diagnosed by CBCT.In this case, exact root canal anatomy could not be depicted by using periapical radiographs alone. Therefore, the use of CBCT helped us make a confirmatory diagnosis. The success of this case might be attributed to accurate diagnosis, complete chemo mechanical debridement, and proper obturation of all the three root canals.


Virtually all the articles in literature addressed only a specific type of dislocation. The aim of this review was to project a comprehensive understanding of the pathologic processes and management of all types of dislodgement of the head of the mandibular condyle from its normal position in the glenoid fossa. In addition, a new classification of temporomandibular joint dislocation was also proposed.temporo-mandibular joint dislocation were used for the search. Additional manual search was done by going through published home-based and foreign articles. Case reports/series, and original articles that documented the type of dislocation, number of cases treated in the series and original articles. Treatment done and outcome of treatment were included in the study.A thorough computer literature search was done using the Medline, Cochrane library and Embase database. Key words like A total of 128 articles were reviewed out which 79 were found relevant. Of these, 26 were case reports, 17 were case series and 36 were original articles. 79 cases were acute dislocations, 35 cases were chronic protracted TMJ dislocations and 311 cases were chronic recurrent TMJ dislocations. Etiology was predominantly trauma in 60% of cases and other causes contributed about 40%. Of all the cases reviewed, only 4 were unilateral dislocation. Various treatment modalities are outlined in this report as indicated for each type of dislocation.The more complex and invasive method of treatment may not necessarily offer the best option and outcome of treatment, therefore conservative approaches should be exhausted and utilized appropriately before adopting the more invasive surgical techniques. The mechanism of temporomandibular joint dislocation varies depending on the type of dislocation which may be acute, chronic protracted or chronic recurrent dislocation . This meThe aim of this article is to review, analyze and update the mechanisms and various management options available for the different types of T.M.J dislocation in literature.temporo-mandibular joint dislocation were used for the search. Additional manual search was done by going through published home-based and foreign articles. Relevance of article for inclusion into the study was assessed based on the title, abstract and contents of the full article. The reference list of the reviewed articles was also searched from Medline and Embase database as well as the Thomson Reuters, Wolters Kluwer, Lippincott Williams and Wilkins search engines for Cited and Related literature search based on the relevant title. Case reports/series, and original articles that documented the type of dislocation, number of cases treated in the series and original articles. Treatment done and outcome of treatment were included in the study. Total number of each type of dislocation reported was recorded and the treatment options for each type was analyzed based on the clinical and radiological outcome . A new classification was proposed for Temporomandibular joint dislocation based on the position of the condylar head in relation to the articular eminence.A thorough computer literature search was done using the Medline, Cochrane library and Embase database. Key words like A total of 128 articles were reviewed out which 79 were found relevant. Of these, 26 were case reports, 17 were case series and 36 were original articles. 79 cases were acute dislocations, 35 cases were chronic longstanding TMJ dislocations and 311 cases were chronic recurrent TMJ dislocations.Chronic protracted TMJ dislocations were treated by manual Hippocratic method under G.A in 13 cases, a hook was used to apply traction on the sigmoid notch in 1 case, external elastic traction with arch bars and elastic bands was used in 1 case while assisted open reduction with Bristow's elevator was done in one case (Table 3contd).The number of cases treated by chemical capsuloraphy using sclerosing agents and platelet rich plasma could not be ascertained, 9 cases were treated with autologous blood in the superior joint space and 9 cases with injection into the space and pericapsular tissues. Also, number of cases of chronic recurrent dislocation that received surgical capsuloraphy and placation for lax capsule and ligaments was not obtained. Closed low level condylotomy to allow free movement was done in 2 cases while 4 cases received open condylotomy. Fifteen cases were treated with lateral pterygoid myotomy via intraoral approach (Table 4contd).Also, 101 cases of chronic recurrent dislocation were treated with eminectomy to shorten the articular eminence and allow unrestricted movement/spontaneous reduction of the condylar head. Eminoplasty using miniplates was done in 24 patients and screws was used in 3 cases  eminoplasty without need for wiring or plating while 60 received eminoplasty with onlay grafts wired to the articular eminence. Modified mini-invasive eminectomy and relocation of the lateral pterygoid muscle was done in 1 case.Similar procedure was done for both sides in each bilateral case of chronic protracted and recurrent dislocation. Majority of the cases were adequately followed up for a period of 2-5 years and complications were mainly found in the patients that did eminoplasty with screws. Patients with autologous blood injected around the pericapsular tissues and into the superior joint space had less recurrence rate than those injected into the space alone.Dislocation of the temporomandibular joint is the dislodgement of the head of the condyle from its normal position in the glenoid fossa located in the squamo-temporal portion of the cranial base. It can be partial (subluxation) or complete (luxation), bilateral or unilateral, acute, chronic protracted or chronic recurrent -29. AlsoAnterior dislocations are the most common and occur due to displacement of the condyle anterior to the articular eminence of the temporal bone. Anterior dislocations are usually secondary to an interruption in the normal sequence of muscle action when the mouth closes from extreme opening . The masPosterior dislocations typically occur secondary to a direct blow to the chin. The mandibular condyle is pushed posteriorly toward the mastoid . Injury Superior dislocations, also referred to as central dislocations, can occur from a direct blow to a partially opened mouth. The angle of the mandible in this position and small rounded margined condyle head predisposes to upward migration of the condyle. This can result in fracture of the glenoid fossa with mandibular condyle dislocation into the middle skull base ,52,109. Lateral dislocation is usually associated with mandible fractures. It could be type I (subluxation) or type II (luxation). Type II has been further sub-classified into three, depending on the duration and management applicable. The condylar head migrates laterally and superiorly and can often be palpated in the temporal space ,9,61.Acute dislocation presents within 2 weeks and it is readily reducible by the Hippocratic maneuver. After 2 weeks, spasms and shortening of the temporalis and masseter muscles occur and reduction becomes difficult to achieve manually. This leads to the commencement of chronic protracted dislocation. Also, elongated articular eminence may prevent the sliding back of the head of the condyle into the normal position in the glenoid fossa, in this case, a chronic protracted dislocation with formation of a new pseudojoint with varying degree of movement sets in and such patients have problems with difficulty in closing the mouth (open lock) and deranged occlusion in which there is prognathism of the mandible with anterior cross bite .In cases due to trauma, fibrous and bony consolidation occur anterior to the articular eminence following the sustained pull of lateral pterygoid and head of condyle resulting in ankylosis and deranged occlusion ,34,63.Chronic recurrent dislocations which include those due to habitual wide mouth opening are usually spontaneous and self reducible depending on the degree of alteration of the morphology of the temporomandibular joint and the contiguous structures. When the articular eminence is long, the dislocation will not be easily self reducible. It occurs commonly in patients with hypoplastic eminence, narrow fossa, lax capsule, collagen disorders, small condyle, hypermobility syndromes, oromandibular dystonias and use of neuroleptic drugs ,18Plain T.M.J views especially the transcranio-oblique views, plain and contrast CT scans, i-CAT scans and MRI, linear and rotational plain digital tomograms, are joint arthroscopy are useful to assess the position of the head of the condyle and meniscus in relation to the glenoid fossa, mastoid process, tympanic plate and articular eminence. Recent imaging tools include the Dolphin imaging system which imports 2D facial photographs  on 3D stereographic images to enhance treatment simulation ,41,55.The author has classified dislocation based on relationship of the head of mandibular condyle to the articular eminence seen on clinico-radiological evaluation into three types (I-III).Type I - the head of condyle is directly below the tip of the eminenceType II - the head of condyle is in front of the tip of the eminenceType III - the head of condyle is high up in front of the base of the eminence.Cases of acute antero-medial, medial, lateral, or posterior dislocation can be reduced manually under local or general anaesthesia, analgesic control with or without sedation. Other methods that have been used in literature include the wrist-pivot technique by Lowery et al. 2004,  combinedAcute or chronic superior dislocation is better treated by gap arthroplasty, the impacted condylar head in the middle cranial fossa must be left in place to avoid bleeding, cerebrospinal fluid leakage and infection ,35,52,64Condylectomy is done for prolonged type II (complete/luxation) lateral dislocations, while treatment of type I and early type II is achieved by closed reduction of both dislocation and associated mandibular fractures, and intermaxillary fixation using arch bars, stainless steel ligature and tie wires for 4-6 weeks ,61. WhenFor chronic protracted dislocation, it is usually in the proposed type III position, the Hippocratic maneuver is usually unsuccessful without general anaesthesia and muscle relaxants and even with that, failure rate is high. Conservative methods like elastic rubber traction with arch bars and ligature wires/IMF with elastic bands are useful to achieve reduction in chronic protracted dislocation. Prior to the use of elastic bands, acrylic blocks or impression compound spacer can be placed in between upper and lower teeth to depress the mandible and open up the bite posteriorly, this helps displace the condyle downwards, the elastic bands that are applied front backwards helps to push the mandible/condyle backwards into the fossa after removing the spacer in about 72 hrs to 1 week. Extrusion of the teeth has been reported and it is corrected with bite plane ,103.Bone hook has also been used to apply traction via the sigmoid notch  TractionManual reduction under local anaesthesia/deep temporal and masseteric nerve blocks , conscioIn 1981, Lewis et al.  used BriWhen surgery is indicated for chronic protracted/prolonged dislocation (CPD) especially cases with longer duration, the goal may be to reposition the condyle in the glenoid fossa and restore movement; or if there is movement in the new position, the goal will be to set back the protruded mandible and correct occlusion. When temporalis is short and spastic, Laskin proposed an intraoral surgical approach to the muscle via a coronoid incision to do a temporalis myotomy . Where aGotlieb advocated condylectomy and coronoidectomy in cases where there is ankylosis but there is possibility of entering the base of the skull and excessive bleeding from pterygoid plexus, internal maxillary and middle meningeal vessels .Vertical and oblique ramus osteotomies have therefore, been described by many authors but these have the disadvantages of less bone contact, and impingement/impaction of the coronoid process on the condyle and the new joint, causing restrictions of movement ,112,113.Inverted L-shaped ramus osteotomy has been described by Adekeye in 1976  to ensurBilateral sagittal split technique offers a better outcome for correction of occlusion because there is no extraoral scar, risk of damage to inferior alveolar bundle is reduced in experienced hands and there is improved bone contact. Also, there is less post-operative bleeding and swelling from muscular detachment ,112.Chronic recurrent dislocation can be approached by conservative procedures of injecting sclerosing agents, autologous blood or platelet rich plasma into the lax pericapsular tissue and superior joint space weekly over a period of 6 weeks, ,65,113 tMoore and Wood ,99 as weChronic recurrent dislocations not due to oromandibular dystonia respond better to surgical approaches especially when chemical capsuloraphy fails. These include surgical capsuloraphy in which a wedge of the capsule is excised and the tissue repaired (capsular placation) with the goal of restituting and reinforcing the lax capsule, in situations where the eminence is low, it can be augmented or reconstructed with screws, plates or implants to improve the height.Depending on the predisposing factor or morphology of the temporomandibular joint, the surgical procedures used to treat chronic recurrent dislocation may be directed towards restricting the condylar movement, creating a mechanical obstacle along the path of condylar translation or removing the mechanical obstacle in the condylar path.Many surgeons have enhanced self reduction of chronic recurrent dislocation that cannot be easily self reduced due to elongated articular eminence by performing total eminectomy described by Myraugh in 1951  to removDautery and his colleagues in other to create mechanical obstacle along the condylar path, performed an osteotomy of the zygomatic arch and displaced the anterior segment downwards and inward to serve as a stop to the forward and upward movement of the condyle head . This caNorman and his colleagues used interpositional eminoplasty in which bone grafts from the iliac or calvaria was sandwiched in the gap created in the middle of the articular eminence . They diAlthough procedures on the articular eminence seems to be gaining much popularity in recent times, eminectomy whose validity has been demonstrated by several authors, removes the bony obstacle, preventing condylar locking, but, these procedures does not address the un-coordinated muscle activity and the lax capsule or ligament, and this made some surgeons to adopt a modified mini-invasive eminectomy and relocation of the lateral pterygoid muscle or redirection of the temporalis muscle which aims to act on both the obstacle and the cause with respect to restoration of TMJ biomechanical constraints ,103,115.Meniscoplasties and menisectomies are relevant procedures done when altered disc morphology and position cause dislocation or prevent self reduction. Total joint replacements should be considered when all appropriate treatments fail in chronic protracted and chronic recurrent dislocations, especially those with associated degenerative joint diseases ,103,107.The difficulty index assesses the ease of the manual reduction method to achieve a reduction of the condyle into its normal position in acute or chronic protracted dislocation and it is directly related to the position of the condylar head and the height of the articular eminence. Also, the frequency of recurrent dislocation and the self reducibility can be inversely linked to the height of the articular eminence.The more complex and invasive method of treatment may not necessarily offer the best option and outcome of treatment, therefore conservative approaches should be exhausted and utilized appropriately before adopting the more invasive surgical techniques which should be done after thorough assessment and treatment planning . SurgicaThe author declares that they have no competing interests.


The availability of raltegravir plus atazanavir provides an alternative antiretroviral strategy that may be equally efficacious and less toxic than those currently recommended in HIV treatment guidelines. In fact, this new combination antiretroviral therapy attracts the attention of the scientific community because both drugs have a good safety profile coupled with potent antiviral activity, and their combined use would avert nucleoside- and ritonavir-related toxicities.We describe the case of a 47-year-old, Caucasian woman treated for HIV-1 infection who developed Buffalo Hump during antiretroviral therapy, including raltegravir and unboosted atazanavir. Clinical evaluation and an ultrasonography scan of the cervical region showed a new progressive increase of lipohypertrophy and the results of DEXA confirmed these data. In our patient the worsening of the Buffalo Hump cannot be attributed to hypercortisolism; insulin-resistance, diabetes, dyslipidemia, hyperlactatemia and metabolic syndrome were not present. Moreover, she was not in therapy with antiretroviral drugs that are described as the cause of Buffalo Hump; on the other hand she developed this side effect three months after the switch of the antiretroviral therapy to raltegravir plus unboosted atazanavir.Current data indicate that the etiology of HIV-associated Buffalo Hump remains elusive but is likely multifactorial; a possible contributing cause, but not the main cause, could be exposure to antiretroviral drugs. To the best of our knowledge, this is the first report on development of Buffalo Hump in the course of antiretroviral therapy, including the use of these drugs. On the basis of our data we can formulate the hypothesis of a pharmacological pathogenesis that underlies the development of this case of Buffalo Hump in the absence of other risk factors. Furthermore, the combination is well tolerated and has a low incidence of adverse effects [et al. during a study in healthy subjects were generally "mild-to moderate" in intensity. Common side effects seen when both drugs were taken were jaundice and headache [et al. evidenced that after five to seven months of therapy based on RAL plus ATV no patients discontinued treatment due to drugs used in therapy, adverse events, and no one had a grade 3 or 4 lab toxicity [Antiretroviral (ARV) treatment guidelines currently recommend ARV regimens containing a Nucleos(t)ide Reverse Transcriptase Inhibitors (N(t)RTIs) based backbone with a Non Nucleoside Reverse Transcriptase Inhibitor (NNRTI) or ritonavir boosted Protease Inhibitor (PI/r). However, significant toxicity has been associated with N(t)RTI(s) and PI/r containing regimens. Recent data presented by Gupta  effects . Moreoveheadache . RipamonWe describe the case of a 47-year-old, Caucasian woman treated for HIV-1 infection, who developed buffalo hump during antiretroviral therapy consisting of RAL and unboosted ATV. She was diagnosed with HIV disease in February 1999: the CD4+ cell count was 214/mm3 (11%) and the HIV viral load was 253,200 copies/ml at that stage. An initial highly active antiretroviral therapy (HAART) regimen consisted of zidovudine, lamivudine and indinavir. After 18 months, the therapy was changed to stavudine, lamivudine and nevirapine because of an episode of acute renal colic. Our patient attended outpatient clinics on a regular basis, and was found to have a good immunological and virological response to HAART. By July 2004, she presented with a progressive peripheral fat loss; facial lipoatrophy was apparent but not severe. For these reasons the HAART combination was changed (November 2004), and stavudine was replaced by a nucleotide analogue tenofovir. The CD4+ count was 599/mm3 (16%) and the HIV viral load was < 50 copies/ml at the change of the antiretroviral medications. She was on nevirapine and lamivudine plus tenofovir for five years with a good immune-virological response. We observed neither other fat accumulation nor fat loss and no significant metabolic disorders after the switch. Body Mass Index (BMI), glucose, cholesterol, triglyceride, plasma cortisol and insulin concentrations were normal.In November 2009 the patient presented with a HIV viral load of 1551 copies/ml; a subsequent test of resistance showed the presence of K65R, K103S, M184V, and G190A. Because she refused therapies with an increased risk of metabolic alterations, the antiviral treatment was changed to RAL 400 mg with unboosted ATV 200 mg twice daily.Three months later, it was noted that she developed a new progressive increase of lipohypertrophy of the dorso-cervical region of the neck. There was no localized accumulation of fat in her abdomen and in the submental region of her neck. The hump in the back of her neck was causing neck pain, headaches off and on and sleep apnea. It was causing her discomfort and affecting the motion of her neck. An ultrasonography scan of the cervical region reported a large amount of subcutaneous fat around the posterior aspect of the neck Figure . The resIn the next three months she developed a massive lipohypertrophy of the dorso-cervical region of her neck. For this reason the plastic surgery staff proposed surgical removal of the BH due to discomfort, localized pain and the progressive increase of lipohypertrophy of the dorso-cervical region of the neck. The patient refused this option and six months later we observed a stabilization of the subcutaneous fat of the cervical region.et al. reported that Buffalo Hump adipose tissue shows specific disturbances in gene expression with respect to subcutaneous fat from HIV-1-infected/HAART-treated patients [et al. reported that patients with Buffalo Hump had higher BMI and more total limb and abdominal fat than patients without Buffalo Hump. Current data indicate that a possible contributing cause, but not the main one, could be exposure to antiretroviral drugs: risk factors for Buffalo Hump are longer duration of use of protease inhibitors and longer duration of use of zidovudine [et al. showed that Buffalo Hump was associated with treatment with saquinavir, indinavir, efavirenz, tenofovir and stavudine. Moreover, time of exposure to stavudine and fat loss, one of stavudine's major side-effects, were associated with Buffalo Hump [Buffalo Hump is commonly reported in adults with HIV-associated lipodystrophy. Accumulation of fat over the dorso-cervical spine is reported in 2% to 13% of HIV infected patients with a higher prevalence 6 to 13%) in those showing any other feature of the lipodystrophy syndrome . The patpatients . Some re to 13% ipatients . The clodovudine . Palacioalo Hump . Previoualo Hump ,5.We report the development of the Buffalo Hump cannot be attributed to hypercortisolism; insulin resistance, diabetes, dyslipidemia, hyperlactatemia and metabolic syndrome were not present. Moreover, there were no significant changes noted in our patient's diet, body weight and BMI. Her lifestyle was normal and she followed a regular exercise program.At the moment she is not in therapy with antiretroviral drugs that are described as the cause of Buffalo Hump; on the other hand she developed this side effect three months after the switch of the antiretroviral therapy to RAL plus unboosted ATV. A caveat of this report is that she had a history of exposure to antiretroviral drugs  associated with the development of Buffalo Hump. This condition may have predisposed the patient to develop the disorder and could constitute a background that contributes to the final appearance of buffalo hump after raltegravir plus atazanavir treatment. Current data indicate that the etiology of HIV-associated Buffalo Hump remains elusive but is likely multifactorial and includes, metabolic disorders, genetic factors, receipt of ART and HIV infection itself .The availability of RAL and ATV provides an alternative ARV strategy that may be equally efficacious and less toxic than those currently recommended in HIV treatment guidelines. However, there are few data in the literature available to date regarding such a combination. There are no publications today that describe a relationship between RAL and unboosted ATV therapy and the occurrence of Buffalo Hump. This is the first report on the development of Buffalo Hump in the course of antiretroviral therapy including these drugs: on the basis of our data we can formulate the hypothesis of a pharmacological pathogenesis that underlies the development of this case of Buffalo Hump in absence of other risk factors. More investigation is required to determine if RAL plus unboosted ATV is a safe alternative to RTV boosted PI based ARV strategies and if there are significant side effects related to this ARV treatment.Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.The authors declare that they have no competing interests.GC has made substantial contributions to conception and design, acquisition of data, analysis and interpretation of data. GD was involved in drafting the manuscript or revising it critically for important intellectual content. FM and CR made substantial contributions to the acquisition of data. CMM, BC and VV gave final approval of the version to be published. All authors have read and approved the final manuscript.


Laryngeal leiomysarcoma is an extremely rare malignancy originating from smooth muscle cells. Its rarity is due to the fact that only less than 50 cases of pure laryngeal leiomyosarcoma and less than 10 cases of hypopharyngeal leiomyosarcaoma have been reported in modern medical literature. Even though the clinical presentation mimics that of a laryngeal carcinoma forming the major bulk of the laryngeal malignancies, the difference in management, warrants an accurate diagnosis. We reported a case of this very rare malignancy presenting in the supraglottic region by highlighting the clinical features, histological and radiological diagnosis and management of this extremely rare malignant entity. An accurate histological diagnosis may be difficult; but supplementing by electron microscopy and immunohistochemical staining, the diagnosis can be reached certainly. Malignant mesodermal neoplasms of the larynx are very rare: accounting for less than 1% of all malignant laryngeal tumors . Of thesA 49 year-old male represented severe respiratory distress, odynophagia and dysphagia which were associated with biphasic stridor. The respiratory distress had begun one week ago. No history of smoking or alcohol was observed.Emergent tracheostomy was done. Direct layngoscopy under GA showed a proliferative growth in the supraglottic region extending towards the right side in the aryepiglottic area. There was no damage on growth. Right TVC and right FVC and ant. commissure were tumoral. Left TVC was mobile . The medial wall of right pyriform sinus was tumoral but the apex was normal. The other subunits of hypopharynx were normal. The biopsy of tumor was reported to be granulation tissue.CT scan of the soft tissue of neck showed an irregular opacity in the sub-mucosal region of right supraglottis in central necrosis. The opacity projected into the airway and caused significant obstruction and invaded tumor thyroid cartilage .In the past medical history of the patient, he has had papillary cell carcinoma of thyroid 37 years ago which underwent right hemithyro-idectomy and again 30 years ago he has had suffered left hemithyriodectomy and bilateral neck dissection and external RT. After the second surgery, because of aspiration and dysphonia, injection thyroplasty type 1 was done by Teflon on the right side.Due to the positive history for Teflon injection, it was assumed that granulation tissue on biopsy is Teflon granulation. The signs and symptoms gradually became more severe and second biopsy was done.The second biopsy suggested a malignant mesenchymal tumor. Histological examina- tion showed fascicles of eosinophilic spindle cells, and vesicular texture which is a cigar shaped nuclei with moderate atypia and 10 mitotic figures per high power field .The immunohistochemistry of the specimen was positive for alpha smooth muscle actin, desmin ,vimentinThe patient was then investigated to rule out the possibility of disseminations, which all were negative. Total laryngectomy was done postoperatively; the patient was treated by Adjuvant Radiochemotherapy and followed up.Malignancies of the larynx account for 1-5% of malignancies diagnosed annually. Majority of these tumors are squamous cell carci- nomas. Mesenchymal tissue malignancies or sarcomas form a very insignificant proportion of laryngeal malignancies; accounting roughly 1% . LeiomyoLeiomyosarcoma originates from the smooth muscles tissue. It occurs in the region where smooth muscles are in plenty; namely uterus, the gastrointestinal tract and the retroperitoneum. Head and neck leiomyosar- comas account only for 3% of all leiomyosarcomas . The lowMajority of the cases related to the larynx leiomyosarcomas originates in the supraglo- ttic or glottic area . MarioniIn our patient, the tumor also showed an extension in the hypopharynx , which is an even rarer clinical feature. Extensive review of the modern literature showed that there were only less than 10 cases of hypopharyngeal leiomyosarcoma reported; adding to the rarity of the present case . The etiological factors which play in the genesis of this rare malignancy are still unclear unlike the squamous cell carcinomas of the larynx in which smoking and alcohol were important etiological components, their role in leiomyosarcoma larynx is still uncertain. An aberrant differentiation of mesenchyma is postulated as a factor, suggested by the factor that a leiomyosarcoma can occur in an area where smooth muscles are in rarity, namely the head and neck, which may be possible in our patient . AnotherThe diagnosis of a leiomyosarcoma larynx is difficult to appreciate clinically as they are clinically indistinguishable from a laryngeal carcinoma. Hoarseness is a common complaint. But this non-specific complaint occurs both in benign as well as malignant laryngeal growths . LaryngeHead and neck leiomyosarcomas rarely are presented by lymph node metastasis. In our case, there was no lymphadenopathy.The role of conventional microscopy is limited for making a morphological diagnosis of laryngeal leiomyosarcoma. When the findings are supplemented by immunohisto- chemistry and ultrastructural investigations, the diagnosis of this rare tumor is made certainly. Histopatho- logically, laryngeal leiomyosarcoma is characterized by prominent interlacing bundles and fascicular arrangement of spindle-shaped cells with cigar-shaped, blunt–ended nuclei and eosinophilic cytoplasm.Other spindle cell tumors include rhabdomyosarcoma, melanoma, schwanoma, malignant fibrous histiocytoma and sarcomatoid carcinoma. The advent of newer monoclonal antibody techniques aiding an immune- histochemical diagnosis has made the diagnosis easier. Leiomyosarcomas are usually positive for alpha smooth muscle actin and negative for cytokeratins and epithelial membrane antigens. In our case, the tumor was positive for alpha smooth muscle actin, desmin and vimentin and negative for pancytokeratin and S-100 antigens.In 2005, Marioni et al.  stressedRadiological investigations like CT and magnetic resonance imaging play a critical role to determine the extent of the primary surgery planning as well as delivering the information regarding the lymph node status.The rarity of this tumor has resulted in the lack of any conclusions regarding the standard modality of management.Abbas et al in 2005 in theirIn certain cases, endolaryngeal resection or partial laryngectomy has been tried to preserve functionality in early disease status. Radical neck dissection is reported to be reserved in case of obvious cervical lymphadenopathy. The rate of local recurrence following surgical excision ranges from 35-50% (The role of radiotherapy is to be an adjuvant therapeutic modality. Radiation can also have a role in recurrence or in residual disease, but as a primary treatment modality, radiotherapy is less effective . Our patThe scarcity of cases has caused the indecisiveness for chalking out the prognosis of this rare tumor. Literature search has shown that head and neck leiomyosarcomas generally have a survival of 35-50 % . MedicalWith the advent of new immunohisto- chemical techniques, the diagnosis of leiomyosarcomas of the larynx can be picked out from the list of differential diagnosis of spindle cell tumors of the larynx. Such modalities should be freely used for diagnosis in case of the wide difference in the treatment methods for giving the patient a better cure and quality of life.


Megachasma pelagios. The pectoral fin is characterized by three features: 1) a large number of segments in the radial cartilages; 2) highly elastic pectoral fin skin; and 3) a vertically-rotated hinge joint at the pectoral fin base. These features suggest that the pectoral fin of the megamouth shark is remarkably flexible and mobile, and that this flexibility and mobility enhance dynamic lift control, thus allowing for stable swimming at slow speeds. The flexibility and mobility of the megamouth shark pectoral fin contrasts with that of fast-swimming sharks, such as Isurus oxyrhinchus and Lamna ditropis, in which the pectoral fin is stiff and relatively immobile.This is the first known report on the skeletal and muscular systems, and the skin histology, of the pectoral fin of the rare planktivorous megamouth shark  Megachasma pelagios) was captured off Hawaii in 1976. It was described as a new genus and species in its own family within the order Lamniformes, and it became the third known planktivorous shark, along with basking and whale sharks The first specimen of a megamouth shark  to describe the skeletal and muscular systems of the megamouth shark pectoral fin; and 2) to discuss the locomotory style of the megamouth shark based on the study of its fin anatomy.Anatomical and histological features were examined in two specimens. The first specimen is a female with a total length (TL) of 3.7 m and a body weight (BW) of 361 kg (OCA-P 20110301). It was incidentally caught on 9 July 2007 during a purse seine fishing operation off Ibaraki prefecture, Japan. The specimen was kept frozen at Okinawa Churaumi Aquarium  prior to anatomical analysis. Following external observations, on 2 March 2011, the left pectoral fin and girdle were removed at Okinawa Churaumi Aquarium and fixed in 20% formalin at Tokai University  for later anatomical examination.The second specimen is a female of 5.4 m TL that was incidentally caught in a set net off Shizuoka prefecture, Japan, on 24 June 2011 (OCA-P 20111217). This specimen was also kept frozen at Okinawa Churaumi Aquarium prior to anatomical analysis. The specimen was partly dissected  and fixed in 20% formalin at Okinawa Churaumi Aquarium. Since 20 March 2012 the specimen has been exhibited at the Main Rest House, Churaumi Plaza, next to Okinawa Churaumi Aquarium.All the specimens of fishes analyzed in this study were accidentally caught by fishermen and are housed at Okinawa Churaumi Aquarium. The aquarium issued permits allowing examination of the specimens as part of this study.The anatomical terminology of the endoskeletal and muscular systems follows that of Elasmobranchs have cartilaginous skeletons whereby individual pieces of the skeleton are comprised of uncalcified cartilage with a mineralized outer layer. The pectoral fins are connected to the pectoral girdle proximally, with the skeletal support for the fins consisting of three larger elements proximally , articulating distally with a series of radial cartilages . We measAlopias vulpinusCarcharias taurusCarcharodon carchariasCetorhinus maximusLamna nasusMitsukurina owstoniOdontaspis feroxPseudocarcharias kamoharaiAlopias superciliosus , Isurus oxyrinchus , and Lamna ditropis .We compared the radial numbers and segment numbers in the megamouth shark with those reported from other lamniform species, including Lamna ditropis (HUMZ117738) and Isurus oxyrhinchus (HUMZ136626) were collected and stained using the same methods as those described above.Skin samples were taken from three sites on the left pectoral fin of megamouth shark specimen OCA-P 20110301 . The tisThe external morphological measurements of OCA-P 20110301 are presented in The proximal region of the pectoral fin consists of three basal cartilages, which, from the anterior to the posterior of the fin, are the propterygium (pt), mesopterygium (ms), and metapterygium (mt) cartilages, as in other sharks . The basTwenty three radial cartilages, which are shaped as slender rods, support the distal region of the pectoral fin. The cartilages, which are oriented towards the anterior pectoral margin, extend 88% of the length of the fin; these features show that the fin is a ‘plesodic-type’ fin sensu  Fig. 2)Fig. 2). The pectoral muscle consists of a dorsal pectoral musculature, the levator pectoralis (lpe), and a ventral pectoral muscle, the depressor pectoralis (dpe) .The lpe extends posterolaterally and covers the dorsal side of the pectoral fin. It originates from a wide shallow medial concavity in the pectoral girdle, and inserts onto the dorsal sides of the basal cartilages and radials. This muscle extends distally to approximately one-third of the length of the radials.The dpe is subdivided into two components which have different origins and insertions. The anterior component (dpe 1) originates from a concavity on the lateral side of the pectoral girdle, and inserts on the anterior edge of the propterygium cartilage (pr); this component is referred to as the “protractor muscle” in some references The radial number of the megamouth shark (23) is within the range of the number in other lamniform species (16–34) . In contThe dermis of the megamouth shark consists of papillary and reticular regions . The forLamna ditropis and Isurus oxyrhinchus, as in that of the megamouth shark, consists of papillary and reticular regions  is so far the greatest among sharks. Because each radial segment in sharks is distally articulated with an adjacent radial segment by connective tissues, the large number of radial segments in the megamouth shark may enhance fin flexibility.Lamna ditropis and Isurus oxyrhinchus. This suggests that the pectoral fin skin of the megamouth shark is suppler than that of the pectoral fins of the other two sharks.High skin elasticity. The skin of the pectoral fin of the megamouth shark is unique in having dense naked-skin networks on its surface. This network may function to increase skin elasticity A hinge joint between the pectoral fin and girdle with a rotation axis nearly perpendicular to the fin surface. This structure indicates that the megamouth shark has the capacity for a high degree of rotation of its pectoral fin forward and backward. Such movement is largely restricted in most sharks, where the pectoral fins typically articulate with the coracoid via an anteroposteriorly broad articulation surface, largely limiting pectoral fin motion to the dorsoventral plane  [8], [20http://www.arkive.org/megamouth-shark/megachasma-pelagios/video-00.html), and in which the right and left pectoral fins are rotated asymmetrically .Based on these morphological and histological features, we conclude that the pectoral fin of the megamouth shark is highly flexible and mobile. This hypothesis is confirmed by video and still images of a live specimen, in which the pectoral fin is tightly bent, with its ventral side facing upwards . This swimming speed is one of the slowest known among elasmobranchs The flexible and mobile pectoral fin of the megamouth shark is probably associated with a slow-swimming planktivorous ecology. According to acoustic tracking data, the megamouth shark swims at a speed of 1.5–2.1 km hIsurus oxyrhinchus and Lamna ditropis. Flexible and mobile pectoral fins may provide high controllability for body posture and depth, although the motions cause large hydrodynamic disturbances I. oxyrhinchus and L. ditropis may reduce self-generated hydrodynamic disturbances, allowing energetically efficient swimming at high speeds The flexibility and mobility of the pectoral fins of the megamouth shark strongly contrast with the stiff and relatively immobile pectoral fins of cruising specialists such as


To assist educators and researchers in improving the quality of medical research, we surveyed the editors and statistical reviewers of high-impact medical journals to ascertain the most frequent and critical statistical errors in submitted manuscripts.The Editors-in-Chief and statistical reviewers of the 38 medical journals with the highest impact factor in the 2007 Science Journal Citation Report and the 2007 Social Science Journal Citation Report were invited to complete an online survey about the statistical and design problems they most frequently found in manuscripts. Content analysis of the responses identified major issues. Editors and statistical reviewers (n = 25) from 20 journals responded. Respondents described problems that we classified into two, broad themes: A. statistical and sampling issues and B. inadequate reporting clarity or completeness. Problems included in the first theme were (1) inappropriate or incomplete analysis, including violations of model assumptions and analysis errors, (2) uninformed use of propensity scores, (3) failing to account for clustering in data analysis, (4) improperly addressing missing data, and (5) power/sample size concerns. Issues subsumed under the second theme were (1) Inadequate description of the methods and analysis and (2) Misstatement of results, including undue emphasis on p-values and incorrect inferences and interpretations.The scientific quality of submitted manuscripts would increase if researchers addressed these common design, analytical, and reporting issues. Improving the application and presentation of quantitative methods in scholarly manuscripts is essential to advancing medical research. Attention to statistical quality in medical research has increased in recent years owing to the greater complexity of statistics in medicine and the focus on evidence-based practice. The editors and statistical reviewers of medical journals are charged with evaluating the scientific merit of submitted manuscripts, often requiring authors to conduct further analysis or content revisions to ensure the transparency and appropriate interpretation of results. Still, many manuscripts are rejected because of irreparable design flaws or inappropriate analytical strategies. As a result, researchers undertake the long and arduous process of submitting to decreasingly selective journals until the manuscript is eventually published. Aside from padding the authors' résumés, publishing results of dubious validity benefits few and makes development of clinical practice guidelines more time-consuming ,2. This To assist educators and medical researchers in improving the quality of medical research, we conducted a survey of the editors and statistical reviewers of high-impact medical journals to identify the most frequent and critical statistical and design-related errors in submitted manuscripts. Methods experts have documented the use and misuse of quantitative methods in medical research, including statistical errors in published works and how authors use analytical expertise in manuscript preparation -11. HoweWe identified the 20 medical journals from the "Medicine, General & Internal" and "Biomedical" categories with the highest impact factor in each of the 2007 Science Journal Citation Report and the 2007 Social Science Journal Citation Report. Journals that do not publish results with statistical analysis were discarded, yielding 38 high impact journals. Twelve of these journals endorse the CONSORT criteria for randomized controlled trials, 6 endorse the STROBE guidelines for observational studies, and 5 endorse PRISMA criteria for systematic reviews. These journals are listed in Additional file The Editors-in-Chief and identifiable statistical reviewers of these journals were mailed a letter informing them of the online survey and describing the forthcoming email invitation that contained an electronic link to the survey instrument (sent within the week). We sent one email reminder a week after the initial email invitation in spring of 2008. We also requested that the Editors-in-Chief forward the invitation to their statistically-oriented editors or reviewers in addition to or instead of completing the survey themselves. An electronic consent form with the principal investigator's contact information was provided to potential respondents emphasizing the voluntary and confidential nature of participation. The Stanford University Panel on Human Subjects approved the protocol. This is one in a series of five studies surveying the editors and reviewers of high-impact journals in health and social science disciplines  ,14.The survey contained three parts: (1) Short-answer questions about the journals for which the respondents served, how many manuscripts they handled in a typical month, and their areas of statistical and/or research design expertise; (2) The main, open-ended question which asked: "As an editor-in-chief or a statistically-oriented reviewer, you provide important statistical guidance to many researchers on a manuscript-by-manuscript basis. If you could communicate en masse to researchers in your field, what would you say are the most important (common and high impact) statistical issues you encounter in reviewing manuscripts? Please describe the issues as well as what you consider to be adequate and inadequate strategies for addressing them."; and (3) One to four follow-up questions based on the respondents' self-identified primary area of statistical expertise. These questions were developed by polling 69 researchers regarding what statistical questions they would want to ask the editors or statistical reviewers of major journals.Responses to the open-ended questions were analyzed qualitatively using content analysis to identify dominant themes. We coded the responses to the main question on the most common and high impact (per the wording of the question) statistical issue and the respondents' proposed solutions to those issues. In the analysis phase, two of the authors resolved coding criteria and sorted the responses according to the two major categories that emerged from the data.A. Statistical and sampling issuesB. Inadequate reporting clarity or completenessThe results are presented in each category from most frequently mentioned to least frequently mentioned.Respondents to the survey were comprised of 25 editors and statistical reviewers (of 60 solicited) who manage manuscripts from 20 of the 38 journals in the sampling frame. Respondents indicated reviewing or consulting on a mean of 47 (range: 0.5 to 250) manuscripts per month. The most frequently reported areas of expertise (multiple responses possible) were the design and analysis of clinical trials (n = 12), general statistics (n = 14), quasi-experimental/observational studies (n = 12), and epidemiology (n = 11).Respondents often noted problems that are fundamental to research design and quantitative methods, including analytical strategies that are incomplete or mismatched with the data structure or scientific questions, failure to address missing data, and low power. Below, we describe the specific issues mentioned by respondents and provide accessible references for more detailed discussion.(1) Inappropriate or incomplete analysis: In addition to minor arithmetic and calculation errors, respondents expressed concern over researchers' choice of statistical tests. Specifically, frequent problems exist in the appropriateness of statistical tests chosen for the questions of interest and for the data structure. These include using parametric statistical tests when the sample size is small or in the presence of obviously violated assumptions . In addi(2) The substantive area of analysis that received the most attention from respondents was the failure to account for clustered data and the use of hierarchical or mixed linear models. The reviewers often observed that authors fail to account for clustering when it is present. Examples of this include data collected on patients over time, where successive observations are dependent upon those in the previous time period(s), or multiple observations are nested in larger units . In these situations, reviewers prefer to see an analytical approach that does not have an independence assumption and properly accounts for clustering, including time series analysis, generalized linear mixed models, or generalized estimating equations where the population-averaged effect is of interest -24.(3) Addressing missing data: Frequently, researchers fail to mention the missing data in their sample or fail to describe the extent of the missing data. Problems with low response rates in studies are often not addressed or are inadequately discussed. In addition, longitudinal studies may fail to address differential dropout rates between groups that may have an effect on the outcome. In addition, those researchers who do discuss missing data often do not describe their methods of data imputation or their evaluation of whether missing data are significantly related to any observed variables. Those researchers who do explicitly address missing data regularly use suboptimal approaches. For example, investigators with longitudinal data often employ complete case analysis, last observation carried forward (LOCF) or other single imputation methods. These approaches can bias estimates and understate the sample variance. Preferably, researchers would evaluate the missing at random (MAR) assumption and conduct additional sensitivity analyses if the MAR assumption is suspect ,26. In a(4) Power and sample size issues: Power was another area that reviewers mentioned as problematic. Respondents also noted that power calculations are not done at all or are done post hoc rather than being incorporated into the design and sampling framework . In nove(5) Researchers often use propensity scores without recognition of the potential bias caused by unmeasured confounding -30. PropIn addition to specific analytical concerns, respondents also reported common errors in the text of methods and results sections. Although some of these problems are semantic, others reflect a misinterpretation or misunderstanding of the methods employed.(1) Inadequate description of methods and analysis: Respondents observed that manuscripts often do not contain a clear description of the analysis. Authors should provide as much methodological detail as possible, including targeted references and a statistical appendix if appropriate. One respondent provided a rule of thumb whereby an independent reader should be able to perform the same analysis based solely on the paper. Other issues included inadequate description of the study cohort, recruitment, and response rate, and the presentation of relative differences  in the absence of absolute differences . As one respondent wrote, "Since basic errors that are easily identified remain common, there is real concern of the presentation of analyses for more complex methods where the errors will not be testable by the reviewer."(2) Miscommunication of results: Researchers frequently report likelihood ratios for diagnostic tests  without associated sensitivity and specificity. Although this is very useful for learning how well a test of interest predicts the risk of a given result ,32, editRespondents also noted an undue emphasis on p-values and excessive focus on significant results. For example, authors often highlight the significance of a categorical dummy that is not significant overall; the overall significance of a multi-category predictor should be tested by using an appropriate joint test of significance . In turnJournal editors and statistical reviewers of high-impact medical journals identified several common problems that significantly and frequently affect the quality of submitted manuscripts. The majority of respondents underscored the fundamentals of research methods that should be familiar to all scientists. These include rigorous descriptions of sampling and analytic strategies, recognition of the strengths and drawbacks of a particular analytical approach, and the appropriate handling of missing data. Respondents also discussed concerns about more advanced methods in the medical research toolkit. Specifically, authors may not understand or report the limitations of their analysis strategies and hedge these with sensitivity analyses and more tempered interpretations. Finally, respondents emphasized the importance of the clear and accurate presentation of methods and results.Although this study was not intended as a systematic or comprehensive catalog of all statistical problems in medical research, it does shed some light on common issues that delay or preclude the publication of research that might otherwise be sound and important. Moreover, the references included in this paper may provide some useful analytical guidance for researchers and for educators. Accordingly, this work serves to inform medical education and research to improve the overall quality of manuscripts and published research and to increase likelihood of publication.In addition, these data provide evidence for the importance of soup-to-nuts methodological guidance in the research process. Statisticians and methodological experts should be consulted during the study design, analysis, and manuscript writing phases to improve the quality of research and to ensure the clear and appropriate application of quantitative methods. Although this may seem obvious, previous work by Altman and his colleagues demonstrates that this is rarely the case in medical research . Rather,This work should be interpreted in light of several important limitations. We did not collect data on the professional position  of the respondents and consequently do not know the composition of the sample or how this may have shaped our findings. Although the response rate was similar to other surveys of journal editors, and we have no reason to suspect significant response bias, the possibility of response bias remains. In addition, the size of our sample may limit the generalizability of our findingsOverall, this work is intended to inform researchers and educators on the most common pitfalls in quantitative medical research, pitfalls that journal editors note as problematic. Given the recent clinical research priorities of health care agenda-setting organizations, such as comparative effectiveness research and evidence-based practice, medical research is expected to meet a new bar in terms of valid and transparent inquiry -39. ImprThe authors declare that they have no competing interests.SFT was responsible for the analysis and interpretation of data, drafting the manuscript, and final approval of the draft. JKH made substantial contributions to the conception and design of the study and the survey instrument, was involved in revising the manuscript, and gave final approval. RNR aided in data collection, analysis and interpretation of the data, manuscript revisions, and gave final approval. AHSH made substantial contributions to the conception and design of the study and the survey instrument, was involved in revising the manuscript, and gave final approval.Appendix. 2007 Journal Citation Report titles included in the sampling frame.Click here for file