Lead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and experimental animals and causes infertility and other adverse effects. The present paper investigated the effects of prenatal exposure to lead on different parameters of estrogen stimulation in the uterus of the prepubertal rat. In prenatally and perinatally exposed rats, estrogen-induced endometrial eosinophilia, endometrial stroma edema, and eosinophil migration towards the endometrium, and uterine luminal epithelial hypertrophy are enhanced while several other responses to estrogen appear unchanged. These effects may contribute to decrease in fertility following prenatal exposure to lead. The striking difference between most of these effects of prenatal exposure and the previously reported effects of chronic exposure to lead suggests that prenatal exposure to lead may neutralize the effects of chronic exposure to lead, providing partial protection of cell function against the adverse effects of chronic exposure to lead. We propose that the mechanism involved, named imprinting or cell programming, persisted through evolution as a nongenetic adaptive mechanism to provide protection against long-term environmental variations that otherwise may cause the extinction of species not displaying this kind of adaptation. Infertility and other reproductive alterations may be caused by a myriad of environmental toxic agents, among them lead. This toxic environmental pollutant is widely spread and affects both male and female reproductive systems in humans  and in eSeveral mechanisms may be involved in the alteration of fertility by lead, which were mainly investigated in experimental animals. Among them, changes may occur at the enzyme levels , 11 or iThe heterogeneity of biochemical processes related to fertility that are affected by lead, together with the existence of multiple and independent mechanisms of estrogen action , 24, 25,Besides chronic exposure to lead, prenatal and perinatal exposure to the pollutant is one of the most common conditions affecting human population. Since the first reports linking the development of clear cell cervicovaginal adenocarcinoma in young women with diethylstilbestrol treatment of their mothers during pregnancy , it becaδ- [μ-opioid, but not κ-opioid receptors [Although few studies investigated the effects of prenatal exposure to lead, several delayed effects were already reported in brain, ovary, and uterus. In the rat brain, prenatal exposure to lead was found to cause a permanent increase in the affinity of δ-  and μ-opeceptors , that paeceptors . In the eceptors , and in eceptors .The report of delayed effects caused by prenatal exposure to lead at uterine estrogen receptor level suggests the possibility that exposure may cause persistent alterations in the action of the hormone in the uterus. The present study describes the effect of prenatal exposure to lead on estrogen action in prepubertal rat uterus, and compares these effects to those previously reported following chronic exposure to the pollutant. Additionally, the present study investigated the possible hematologic changes in rats prenatally exposed to lead, taking into consideration the role of eosinophil leukocytes in estrogen action .The experimental conditions in the present study are intended to investigate, in an animal model, conditions frequently occurring in the human species: pregnant women displaying high lead blood levels as a cause of their child's prenatal exposure to lead; subsequent breast feeding as the source of the continuation of exposure after birth.vivarium of the Faculty of Medicine, University of Chile, were used in the present study. Four groups of female pregnant animals were subjected to the following procedure. The animals received a single dose of lead acetate  of 235 μg Pb++ g−1 body wt s.c.  or saline physiological solution, at the 14th day of pregnancy . From some lead exposed pregnant rats not included in the study of their offspring, blood samples were taken at 24, 48 72, 96, 120, and 168 h after lead injection, for measurement of their blood lead levels. Blood was also obtained from some nonexposed pregnant rats not included in the study of their offspring. The female offspring were allowed to be nursed by their exposed or nonexposed mothers up to day 21 of life, when they were treated with estradiol-17β  or its vehicle . The age of 21 days is the most appropriate for the study of the effects of sex steroids on target organs, since estrogen and progesterone levels are extremely low and receptor levels and hormone responsiveness are already fully developed [Female rats from a Sprague-Dawley-derived colony bred at the The left uterine horn was fixed in 4% neutral formalin and subjected to further histological procedure for eosinophil quantification and morphometric evaluation. Paraffin sections were stained with hematoxylin-eosin as previously described .Blood collected in EDTA containing tubes was used immediately after sample collection for blood cell quantification. Eosinophil quantification and evaluation of eosinophil degranulation  was perfBlood lead concentration was measured in a group of pregnant rats nonexposed to lead (control without lead) and in another group of pregnant rats at various times after lead injection; blood lead levels were also determined in nonestrogen-treated offspring from saline or lead exposed animals, using atomic absorption spectroscopy with graphite furnace at the Chilean Institute of Public Health, Ministry of Health.The following parameters of estrogen stimulation were investigated in the uterus: myometrial hypertrophy was measured as increase in the reciprocal value of cell density (RVCD) in circular myometrium; edema in deep endometrial stroma was evaluated as increase in RVCD in this histological location , 50. Uteχ2 test.Data analysis by the Tukey additivity test suggested that data on uterine eosinophils and blood lead levels should be subjected to a square root transformation to normalize distribution; the remaining data were not transformed due to their normal distribution . Since mμg/dL while pregnant rats 1 to 7 days after lead exposure displayed 35.1 μg/dL; no differences were detected within the 7 days following exposure. The offspring of lead-exposed mothers displayed 20.6 μg/dL at the time of blood and uterus sample collection while offspring of nonexposed control mothers displayed 4.4 μg/dL.Lead levels in adult pregnant rats nonexposed to lead displayed values under 2 μL blood in the offspring at the age of 21 or 22 days. Similarly, no changes in blood eosinophil degranulation were detected under the effect of prenatal exposure to lead (data not shown). Estrogen treatment of either exposed or nonexposed offspring did not induce any changes in these parameters.No effects of prenatal lead exposure were detected in the total number of leukocytes, eosinophils, lymphocytes, monocytes, or neutrophils per P < 0.001, χ2 test). This response to estrogen in prenatally exposed animals was different from previously reported [P < 0.01, χ2 test) in animals under chronic lead exposure.Prenatal exposure to lead strongly enhanced estrogen-induced increase in endometrial eosinophils at 6 h of hormone treatment . This rereported  increasePrenatal exposure to lead strongly enhanced estrogen-induced edema in deep endometrial stroma  at 6 h oPrenatal exposure to lead strongly enhanced estrogen-induced increase in luminal epithelial cell volume 24 h after hormone stimulation . A previLead exposure did not significantly modify estrogen-induced cell hypertrophy in this histological layer, 24 h after hormone stimulation . It was The present study provides evidence that prenatal exposure to lead enhances estrogen-induced uterine eosinophilia 6 h after hormone treatment, mainly in the endometrium while estrogen-induced increase in eosinophils in the mesometrium is not significantly affected. The finding of a decreased proportion of eosinophils located in the mesometrium in prenatally exposed animals suggests increased eosinophil migration from mesometrium towards myometrium and endometrium. This agrees with the increase in estrogen-induced edema in endometrial stroma in prenatally exposed animals, since endometrial edema is mediated by enzymes released from eosinophils migrating to this location; these enzymes depolymerize uterine collagen and ground substance glycosaminoglycans, increasing extravascular osmotic pressure and uterine vascular permeability , 21.Several explanations may be suggested for the enhancement of estrogen-induced eosinophil migration towards endometrium in prenatally exposed rats. Eosinophils may have increased intrinsic ability for migration through connective tissue, they may contain an increased amount of enzymes needed to increase ground substance fluidity, or display increased sensitivity to chemotactic agents; the secretion of a putative eosinophil chemotactic substance by endometrial tissue  may be iThe present report describes an important enhancement of estrogen-induced uterine luminal epithelium hypertrophy under the effect of prenatal exposure to lead. It is similar to that reported following acute , subacutWith regard to hematologic parameters reported to be affected following subacute  or chronIt is striking that three responses to estrogen stimulation , but not the remaining responses , display just the opposite behavior when comparing prenatal exposure and chronic exposure. Estrogen-induced increase in eosinophils in the endometrium appears to be enhanced in prenatally exposed rats while it is inhibited following chronic exposure. Eosinophil migration from mesometrium towards myometrium and endometrium is enhanced in prenatally exposed animals while it is inhibited in chronically exposed rats. Estrogen-induced endometrial edema is enhanced in prenatally exposed rats while the response is inhibited following chronic exposure. The differences appears even more conspicuously, considering that lead blood levels in prenatally exposed rats at the age of estrogen stimulation are much higher than those in nonexposed controls, although lower than following chronic exposure, that is, mimicking a less severe chronic exposure.Since it was reasonable to expect, in prenatally exposed rats, an inhibition of endometrial eosinophilia and edema of a smaller magnitude than in prenatally exposed rats, our finding of enhancement of the responses to estrogen in prenatally exposed animals was completely unexpected. Our finding suggests that prenatal exposure may antagonize the effects of chronic exposure to lead in endometrial eosinophilia and edema, thus providing a partial protection of cell function against adverse effects of chronic exposure to lead.We have previously proposed that estrogen-induced endometrial edema and destruction of endometrial extracellular matrix by plasmin formed by eosinophil plasminogen activators are required to facilitate blastocyst implantation . EosinopNevertheless, at this point, it is not possible to ascertain whether the remaining effects of prenatal exposure to lead in the uterus may interfere with blastocyst implantation and its development in the uterus. Further work is needed to evaluate this possibility as well as effects in other organs of the reproductive system.Imprinting can be considered a general biological epigenetic mechanism. It causes changes in the differentiation or programming in various cell-types under the effect of perinatal exposure to various agents or conditions; these changes persist through life and can be detected through biochemical, morphological, and functional changes in affected cells. We now propose that this process may have persisted through evolution as a non-genetic adaptive mechanism to provide protection against long-term environmental variations that otherwise may cause the extinction of species not displaying this kind of adaptation. In the particular case of lead, it may protect several reproductive functions and their mechanisms against damage by this pollutant, allowing offspring of prenatally or perinatally exposed individuals to survive and further reproduce in a newly polluted environment.Lead is also known to affect other organs and systems. For instance, it causes neurological and neurobehavioral changes that were reported in countries with high lead pollution levels –63. AmonWe conclude from this study that prenatal exposure to lead causes persistent changes in several responses to estrogen in the rat uterus, detected at postnatal age of 21 days, and suggest that prenatal exposure may constitute a non-genetic adaptive mechanism to antagonize some of the adverse effects of chronic exposure to lead in the uterus, thus protecting it against reproductive impairment caused by chronic exposure to lead.


The brain regions functionally engaged in motor sequence performance are well-established, but the structural characteristics of these regions and the fiber pathways involved have been less well studied. In addition, relatively few studies have combined multiple magnetic resonance imaging (MRI) and behavioral performance measures in the same sample. Therefore, the current study used diffusion tensor imaging (DTI), probabilistic tractography, and voxel-based morphometry (VBM) to determine the structural correlates of skilled motor performance. Further, we compared these findings with fMRI results in the same sample. We correlated final performance and rate of improvement measures on a temporal motor sequence task (TMST) with skeletonized fractional anisotropy (FA) and whole brain gray matter (GM) volume. Final synchronization performance was negatively correlated with FA in white matter (WM) underlying bilateral sensorimotor cortex—an effect that was mediated by a positive correlation with radial diffusivity. Multi-fiber tractography indicated that this region contained crossing fibers from the corticospinal tract (CST) and superior longitudinal fasciculus (SLF). The identified SLF pathway linked parietal and auditory cortical regions that have been shown to be functionally engaged in this task. Thus, we hypothesize that enhanced synchronization performance on this task may be related to greater fiber integrity of the SLF. Rate of improvement on synchronization was positively correlated with GM volume in cerebellar lobules HVI and V—regions that showed training-related decreases in activity in the same sample. Taken together, our results link individual differences in brain structure and function to motor sequence performance on the same task. Further, our study illustrates the utility of using multiple MR measures and analysis techniques to specify the interpretation of structural findings. Even with identical practice, no two individuals are able to reach the same level of performance on a motor skill—nor do they follow the same trajectory of improvement as they learn. As neuroscientists, we assume that such individual differences are related to brain structure and function, but relatively few studies have linked performance variability to variability in the brain. Over the last 20 years, work with animals and functional neuroimaging studies in humans have identified the major brain regions involved in learning and performing motor skills  or greater GM volume   who gave written informed consent. All were right handed  while PSYN, the more procedural sensorimotor integration measure, showed a statistical trend toward improvement on LRN (p = 0.10) . Final PCOR performance was very high while final PSYN performance was lower and had greater variability across participants. Figure M = 0.80, SD = 0.82) and PSYNslp  measures indicated that participants, on average, improved over the course of the experiment. Individual final PCOR and PSYN, PCORslp, and PSYNslp values were used in subsequent correlational analyses to explore the relationship between motor performance and brain structure.Subjects were trained to produce accurate and synchronized button presses in response to a 10 element visually presented motor sequence across 5 days of practice. Within-subjects ANOVAs revealed that PCOR, the more explicit sequence ordering measure, improved significantly over the course of the experiment [PCOR: p = 0.07, fully corrected for multiple comparisons. There were no statistically significant correlations between PCORslp/PSYNslp and FA.FA was correlated with behavior to identify individual differences in WM integrity related to performance. Final PSYN was found to correlate negatively with FA within bilateral CST, such that participants with greater final synchronization performance had lower FA in these clusters. In the left hemisphere, one cluster was located directly below the hand area of the primary motor cortex M1)  while axial diffusivity did not (p = 0.18). In addition, FA and radial diffusivity were negatively correlated . Figure Axial and radial diffusivity values were extracted from the identified region to investigate their contributions to the negative correlation between FA and final PSYN. Axial diffusivity is the diffusivity along the axis of greatest diffusion and radial diffusivity is the mean of diffusivity in the two perpendicular axes. Radial diffusivity was found to positively correlate with final PSYN , the ascending and descending tract extends superiorly to the sensorimotor cortex and inferiorly to the brainstem; this tract location is consistent with the CST  is consistent with the course of the SLF: extending anteriorly to the frontal lobe along the external capsule, posteriorly across the superior part of the CST to the parietal lobe, and laterally to the auditory cortical regions of the temporal lobes  from association fibers (probable SLF). Using the region where FA was found to significantly correlate with final PSYN as the seed  that would be unlikely to be influenced by crossing fibers from the CST. Also possibly consistent with our findings, a recent study showed that non-musicians had greater FA than musicians in bilateral CST regions similar to those observed in our results  where GM volume is important for the speed at which sequence skill is acquired were also identified. Our multimodal cross-sectional individual differences design also illustrates the importance of considering multiple structural measures  within the context of functional results to help provide a more global interpretation of the processes involved in skilled motor sequence performance.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


After the recent summary of World Health Organization–authorized research on smallpox, several clinical issues remain. This policy review addresses whether early hemorrhagic smallpox is disseminated intravascular coagulation and speculates about the cause of the high mortality rate among pregnant women and whether ocular smallpox is partly the result of trachoma or vitamin A deficiency. The joint destruction common in children with smallpox might be prevented by antiviral drugs, but intraarticular infusion of antiviral drugs is unprecedented. Development of highly effective antiviral drugs against smallpox raises the issue of whether postexposure vaccination can be performed without interference by an antiviral drug. Clinicians should consider whether patients with smallpox should be admitted to general hospitals. Although an adequate supply of second-generation smallpox vaccine exists in the United States, its use is unclear. Finally, political and ethical forces suggest that destruction of the remaining stocks of live smallpox virus is now appropriate. These problems included high rates of adverse events associated with most strains of vaccinia virus; our inadequate understanding of the pathophysiology of smallpox; lack of a good animal model of the disease; difficulty of rapid laboratory diagnosis, including the poor ability of most standard laboratory tests to distinguish between orthopoxviruses; lack of an effective antiviral drug; and rudimentary knowledge about the genetic makeup of the virus.After the World Health Organization (WHO) declared smallpox eradicated in 1980, several problems remained concerning the disease and its causative virus, variola major virus–Although many observers wished to destroy the remaining stocks of variola major virus in 1980, several respected researchers wanted to use the live virus to help answer some of these remaining questions. In 1999, WHO agreed to a research agenda, with oversight by a WHO committee, to continue research with live variola major virus until substantial progress was made on these questions. The WHO oversight committee has now declared that satisfactory (if in some areas imperfect) progress has been made toward developing improved vaccines, better laboratory diagnostics, a reasonable nonhuman primate animal model, effective antiviral drugs, and good understanding of the genetics of orthopoxviruses. Reports of this progress have been published . Patients had widespread hemorrhaging in the skin during the early septic phase, usually before a rash developed. Bleeding occurred from multiple orifices. Although necropsy evidence is minimal, internal bleeding likely affected many organs. Results of studies of bleeding time, clotting time, and tourniquet tests in patients with early hemorrhagic smallpox were consistent with what might be expected with DIC  is theoretically possible. Inserting minor modifications into the genome of a well-characterized strain of vaccinia virus should be even easier. Orthopoxviruses are large, stable, DNA viruses that are fairly easy to manipulate genetically . It requires syringes and needles and must be administered by someone trained to give injections. First-generation and second-generation vaccines are lyophilized and can be reconstituted and administered in the field with bifurcated needle scarification by persons with minimal training. Because MVA does not produce a visible lesion or scar, rapid determination of who has been already vaccinated is difficult. Optimal immunity with MVA requires 2 injections. In contrast, single injections are fully protective for first-generation and second-generation vaccines.In the absence of a perfect animal model for smallpox, and because it is impossible to test these vaccines against smallpox, we have only laboratory evidence of their efficacy. Given these limitations, third-generation vaccines may be best for persons who anticipate possible exposure, such as military personnel or laboratory personnel working with orthopoxviruses. In an actual outbreak, ACAM2000 should be used for field vaccination. However, its use increases the risk for development of progressive vaccinia or eczema vaccinatum; these adverse events would then need to be treated with ST-246.WHO is planning on creating a modest real, and substantial virtual, stockpile of vaccines. There are ≈60 million doses of vaccine in this stockpile and plans to increase it to ≈200 million doses. How much of this stockpile should be second-generation or third-generation vaccines that may not yet have been licensed widely? What should be the rules for release of such vaccines from the stockpile? Widespread use of first-generation or second-generation smallpox vaccines in era of AIDS and iatrogenic immune suppression by cancer chemotherapy or for transplant surgery seems unlikely unless there are actual cases of smallpox. In that situation, we might respond by using first-generation and second-generation vaccines with proven efficacies.–The WHO-approved research agenda with variola major virus has been largely fulfilled (Discussions about destruction of the remaining variola major virus stocks should not be limited to the scientific points set forth in the US Institute of Medicine report (


Schizosaccharomyces pombe, providing an important conceptual framework for possible modes of action of ncRNAs also in other organisms. In this review, we highlight mechanistic insights into chromatin-associated ncRNA activities gained from work with fission yeast, and we draw parallels to studies in other eukaryotes that indicate evolutionary conservation.RNA transcripts that do not code for proteins have been long known to lie at the heart of many biological processes, such as splicing and translation. Yet their full potential has only been appreciated recently and non-coding RNAs (ncRNAs) are now attracting increasing attention. Pioneering work in yeast and plant systems has revealed that non-coding RNAs can have a major influence on the deposition of histone and DNA modifications. This can introduce heritable variation into gene expression and, thus, be the basis of epigenetic phenomena. Mechanistically, such processes have been studied extensively in the fission yeast  Recent advances in technologies enabling the profiling of transcriptomes at unprecedented depth have revealed the production of RNA in eukaryotic cells from a proportion of their genomes much larger than anticipated  -related pathways act solely as guide molecules Hannon . With a Caenorhabditis elegans in 1998 -mediated process in NAs Fig.   generated upon DNA damage were proposed to affect protein synthesis after DNA damage by inhibiting rRNA biogenesis  genome RNAs that control transposable elements in the germline of animals have been linked to chromatin regulatory processes. Mutations in piRNA pathway components led to defective DNA methylation in male mouse germ cells , Dicer (Dcr1) and the RNA-dependent RNA polymerase (Rdp1), are essential for the formation of centromeric heterochromatin -containing Chp1 component. Interestingly, the Chp1 CD also possesses intrinsic nucleic acid-binding activity, a property that can further stabilize RITS association with chromatin   gene is linked to Ubx expression. As in the case of SRG1, ncRNA transcription leads to Ubx repression. Finally, extensive truncation and promoter-swap experiments in mice have shown that silencing of the imprinted Ifg2r gene also results from transcriptional overlap between protein-coding and non-coding sequences, without a contribution by the long ncRNA Airn itself (Latos et al. Similar ncRNA-transcription-dependent but ncRNA-independent regulatory processes have been described in other organisms. In Much excitement has been triggered by the notion that eukaryotic cells transcribe a much greater proportion of their genomes than anticipated, and that these seemingly non-protein coding RNAs may add yet another layer of complexity to genome regulation. Clearly, the examples highlighted in this review and others demonstrate that some ncRNAs are functionally highly relevant. However, for most of the “non-coding transcriptome” of different organisms, the extent of ncRNA involvement in regulatory circuits and the mechanisms by which they might act remain largely unexplored. Thus, a future challenge will be to systematically probe ncRNAs for physiological relevance.cis on chromatin. Given the recent advances in genome-editing technologies (Wang et al. The power of yeast has been its genetic tractability, which has allowed specific manipulations of an ncRNA and its underlying genomic sequence in order to perform loss-of-function experiments. The ability to do so is of particular importance when the ncRNA under investigation acts in Most importantly, the properties and functions of ncRNAs, whether or not their activities are associated with chromatin, are likely to be heavily dependent on their interactions with specific proteins. Therefore, we must aim at developing strategies to determine the protein partners of ncRNAs, similar to a recent proteomic study in which close to 800 proteins were identified based on their ability to bind to polyadenylated transcripts (Baltz et al.


The information gleaned from such models can aid in the construction and efficacy of clinical trials and treatment protocols, accelerating the pace of clinical research in the war on cancer. This review focuses on the growing translation of PSM to clinical neuro-oncology. It will also provide a forward-looking view on a new era of patient-specific MNO.Gliomas are notoriously aggressive, malignant brain tumors that have variable response to treatment. These patients often have poor prognosis, informed primarily by histopathology. Mathematical neuro-oncology (MNO) is a young and burgeoning field that leverages mathematical models to predict and quantify response to therapies. These mathematical models can form the basis of modern “precision medicine” approaches to tailor therapy in a patient-specific manner. Patient-specific models (PSMs) can be used to overcome imaging limitations, improve prognostic predictions, stratify patients, and assess treatment response  Gliomas are heterogeneous primary brain tumors that exhibit widely varying phenotypes even within the same histological grade  and computed tomography (CT). However, neither of these imaging techniques quantifies the full extent of tumor invasion due to the inherent limits of detection, as illustrated in Figure Currently, prognosis in glioma patients is based upon retrospective analyses of groups of patients with similar histopathological characteristics  to provide predictive insight onto glioma prognosis and treatment response in individual patients. Although the field of neuro-oncology is broad and encompasses many distinct neoplasms, to date, much of the literature has been devoted to the presentation of models and methodologies for estimating glioma growth from medical imaging and other clinical data.The term Mathematical Oncology was coined in 2003 to reflect the burgeoning synergy between mathematical modeling techniques, cancer research, and clinical oncology . In this case a 75-year-old female presented to the emergency department with a complex partial seizure (CPS), prompting imaging that revealed a large tumor. She refused medical advice to undergo a biopsy to establish a diagnosis and subsequent treatment but allowed multiple imaging observations  and proliferation , both of which can be calculated on a patient-specific basis using routine clinical imaging prior to treatment.In the early 1990s, the research groups of Murray and Alvord developed a mathematical model to describe the diffuse infiltration and proliferation of glioma cells in the complex anatomy of the human brain Figure . This moD) and proliferation (ρ) parameters, D/ρ) relating rates of invasion and proliferation provides two equations and two unknown parameters, tuning the PI model to patient-specific growth. The PI model can further incorporate differential motility of glioma cells through gray and white matter of the brain, providing predictions of diffuse tumor invasion through the regions of the brain that are specific to the patient’s tumor  of glioma growth and infiltration is similar to Fisher’s equation which yields the same predictable pattern of linear radial growth observed in low and high grade gliomas Fisher, . The velr Figure . This sir Figure , hypoxiar Figure , responsr Figure , chemo- r Figure , biologir Figure , and to r Figure . Mass efr Figure . Giatilir Figure  add adiaD and ρ , MRI Spectroscopy, and Diffusion Tensor (DT) MRI have been used to suggest techniques for estimating patient-specific parameters Experimental data suggests that tumor states of proliferative and invasive capacity are mutually exclusive , proliferation (ρ), and prognosis. As illustrated in Figure D and ρ combine with the patient’s MRI to yield a map of the diffuse gradient of glioma cells that is expected to lie beyond thresholds visible to imaging  were significant predictors of prognosis in both univariate and multivariate analyses even when controlling for standard clinical prognostic parameters such as RTOG recursive partitioning analysis (RPA) classification.In a study of 32 newly diagnosed glioblastoma patients, Wang et al.  used theg Figure . Wang etVelocity of radial expansion on MRI and net proliferation rates were compared to RPA classification and it was found that patients with low velocity and proliferation lived longer than the median prognosis associated with each RPA class, and patients with high velocity and proliferation had shorter survival. A therapeutic response index (TRI) was also calculated for each patient. This is defined as the ratio between the patient’s actual survival, and the time it takes for their untreated virtual control (UVC) tumor to reach fatal tumor burden (FTB) Swanson, . Patient18F-Fluoromisonidazole (FMISO) PET images to the region of hyper intensity on T2-weighted MRI. They found that a tumor with high proliferation relative to diffusion would be a relatively well demarcated lesion, while a low ratio would indicate a very diffuse tumor with more migratory capacity compared to the proliferation rate. A metric of tumor shape irregularity was also calculated and found to be negatively correlated with ρ/D. This suggests that more irregularly shaped tumors are formed by cells with relatively high proliferation rates in highly hypoxic environments. These metrics yield patient-specific understanding and quantification of disease burden and relative biological aggressiveness and a tool in the MNO toolbox.Despite the predictable pattern of linear radial growth in gliomas, within histologic grade there may be great variability in response to treatment and overall prognosis  versus gross total (GTR) removal of imageable tumor remains controversial, Swanson et al.  used matin vivo biological effectiveness of radiotherapy in individual patients has remained elusive (Enderling et al., in vivo quantification of radiosensitivity in individual glioma patients as well as a predictive relationship between pre-treatment growth kinetics and response to therapy.Beyond RECIST and Macdonald response criteria (Padhani and Ollivier, In silico models of tumor growth and response to radiotherapy allow for the investigation of factors affecting radiosensitivity and alternative treatment strategies that may be impractical in the clinic. Stamatakos et al. (s et al.  model sts et al.  and Rocks et al.  used a cs et al.  builds uSwanson et al.  used theIn silico models of tumor growth and response to radiotherapy allow for the investigation of alternative treatment strategies that may be impractical in the clinic. Holdsworth et al. (h et al.  leverageh et al.  to generh et al. .Pseudoprogression is a puzzling clinical phenomenon defined by increased contrast enhancement on MRI within 100 days of radiation therapy that spontaneously improves with no subsequent change in treatment (Brandsma et al., Gliomas present a unique clinical challenge. In addition to intra- and inter-tumoral heterogeneity, these lesions are defined by their diffuse invasion of otherwise normal-appearing brain tissue peripheral to the imageable abnormality. This diffuse growth limits the clinical utility of neuroimaging in interpreting treatment response. Current metrics of therapeutic response rely on observable changes to clinical imaging (Wen et al., The future of patient-specific modeling and application depends on asking questions that mathematical models can realistically answer with data that can be obtained from patients either non-invasively or infrequently. PSM must be validated and incorporated into clinical trials to become broadly and directly applicable to patient care. Advantages of a patient-specific modeling approach include:○Identification of individualized tumor proliferation and invasion rates or other kinetic information about an individual patient’s tumor (Swanson et al., ○Development of methods for quantifying and predicting response to therapy – alone and also with respect to UVCs provided by model predictions (Swanson et al., ○More informed treatment planning and response assessment tools that compare each patient’s tumor growth against its own virtual control (Swanson et al., These advantages directly address a number of key unmet challenges in clinical neuro-oncology. In the coming years we anticipate a continued expansion of peer-reviewed journals dedicated to mathematical oncology, coordinated with increased funding for research in the area. Recently, Cancer Research has added a special section devoted exclusively to mathematical oncology, and the NIH has initiated special funding programs targeted at mathematical models through the Integrative Cancer Biology Program and Physical Sciences Oncology Center, among others. By producing individualized virtual tumors that predict disease progression in the absence of treatment, patient-specific modeling can contribute to the ongoing dialog regarding the design of appropriate response criteria (Wen et al., The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Sir,We thank et al (2010) did not perform LMC to ensure the validity of epithelial cell positivity.In our initial publication, we demonstrated the presence of the Epstein–Barr virus (EBV) in malignant breast tumours, which is consistent with findings in previous international publications  concerns the controversial association between EBV and BC. Other retroviruses have been reported to induce BC. In a previous report, Besides, another valuable criticism leveled by Khan The aggressive profile of EBV-positive BC that we observed has previously been reported in other series (Finally, we agree that EBV is a ubiquitous infection that makes the physiopathology of BC development difficult to explain. There is still a long road ahead in the field of virus-related cancer before we will be able to formally assess their role and propose prevention.


Infectious diseases are responsible for an overwhelming number of deaths worldwide and their clinical management is often hampered by the emergence of multi-drug-resistant strains. Therefore, prevention through vaccination currently represents the best course of action to combat them. However, immune escape and evasion by pathogens often render vaccine development difficult. Furthermore, most currently available vaccines were empirically designed. In this review, we discuss why rational design of vaccines is not only desirable but also necessary. We introduce recent developments towards specifically tailored antigens, adjuvants, and delivery systems, and discuss the methodological gaps and lack of knowledge still hampering true rational vaccine design. Finally, we address the potential and limitations of different strategies and technologies for advancing vaccine development. Scourges of humanity, such as smallpox, polio, and measles, have been controlled by vaccination. Other epidemics, for instance tuberculosis, have yet to be sufficiently restrained by immunization. Accordingly, policy makers have given a high priority to the development of novel vaccines to induce protective immunity against selected pathogens. Most human vaccines contain attenuated or killed pathogens and were developed empirically, such as the yellow fever vaccine Rationally designed vaccines are composed of antigens, delivery systems, and often adjuvants that elicit predictable immune responses against specific epitopes to protect against a particular pathogen. In many cases a vaccine cannot be successfully designed due to insufficient knowledge about the mechanisms of protection. Although the repertoire of immune clearance mechanisms to fight pathogens is known, the specific contributions of different effector mechanisms are well-characterized for only a few pathogens. It is also largely unclear what determines the immunogenicity and selection of particular epitopes among all possible antigenic options offered by a pathogen. Which factors determine dominant or balanced immune responses? What are the mechanisms leading to long-term protection? Investigation of immune responses to known effective and ineffective vaccines and of pathogens' strategies of immune escape and evasion generates the basis to tackle these open questions. The approach relies on data from studies with empirically developed vaccines—for now and in the near future.There are no universally accepted strategies and tools to rationally design vaccines. Vaccine development is still generally a tedious and costly empiric process. This review focuses on approaches to overcome empirical vaccine development and addresses their potential and limitations. It will become clear that even the latest developments are mostly first steps. Reports may sometimes sound too optimistic with regard to a prompt implementation of the introduced methods. Nevertheless, multiscale interdisciplinary efforts are strongly needed to reach this goal.in silico selection, high throughput screenings, and profiling technologies  to define promising antigens in relation to in vivo expressed genes and clonal variation Selecting the optimal antigen represents the cornerstone in vaccine design. With the advent of genomics, the traditional process of selecting candidate antigens one by one has been replaced by reverse vaccinology approaches. Namely, the coding potential of a pathogen's genome is exploited by in silico prediction To elicit antibody responses, vaccines should include BCR epitopes. Their prediction is particularly challenging, though, and most B cell epitopes are discontinuous; that is, they are comprised of distant parts of the protein's primary structure. In addition, they are of variable length (3–30 amino acids) and conformation-dependent The proteins or peptides of a subunit vaccine should also display sequences that allow T cell epitope formation in a complex with MHC molecules. MHC class I and II come in hundreds of alleles that are differentially combined between individuals. Choosing immunogenic peptides presented by MHC faces the challenge of not only predicting sequences appropriate for complexing with a particular MHC allele but also finding peptides that can reliably build epitopes in the diverse genetic background within a human population. Drawbacks of in vitro assay-based TCR epitope identification are (i) time consuming procedures for combinatorial coverage of relevant MHC alleles and candidate pathogenic antigens, (ii) high costs for peptide synthesis and reagents, and (iii) limited sensitivity when using naïve T cell populations. These efforts can be reduced extremely when combined with computational TCR epitope prediction In silico prediction of T cell epitopes cannot be based on physico-chemical properties of presented peptides but depends on the application of learning machines on data sets of known MHC allele–peptide pairs. The development and maintenance of databases is absolutely essential to constantly improve predictions In silico generation of mosaic polyvalent antigens tackles this problem + cells Neisseria meningitidis were generated Diversity also occurs at the level of the antigen. Immune escape of pathogen variants through mutation of immunogenic sequences has to be considered when selecting or designing antigens H2-dependent immune responses but promotes less effective cytotoxic responses and can cause side effects. A number of other adjuvants have been recently approved for use in defined human vaccines, such as MF59 and monophosphoryl lipid A-containing formulations Escherichia coli and its attenuated derivative Subunit vaccines are likely to lack the molecular cues needed for efficient activation of the innate immune system, thereby failing to induce vigorous adaptive immunity. PAMPs can act as adjuvants, however many pathogen-derived products might exhibit toxic activity + T cells in humans + and CD8+ responses against SIV antigens delivered by a recombinant CMV vector Delivery systems become necessary when antigens are not efficiently transported to the inductive sites or presented to the immune system. For example, rapid degradation can result in weak or virtually absent responses to otherwise immunogenic antigens. The coding sequence of an antigen can be integrated into a live virus-vector, which infects antigen-presenting cells (APCs), preferentially dendritic cells (DCs) The delivery to DCs can be achieved by coupling antigens to antibodies specific for surface molecules, such as Clec9A. This method leads to antigen uptake and activation of T and B cells Understanding what is needed to confer protection without side effects is a prerequisite to develop a tailored intervention. To date, characterization of human responses to vaccination relies mainly on measuring antibody titers or cellular responses from peripheral blood samples. This does not allow a comprehensive analysis of responses with regard to the effector cells or mechanisms stimulated and the status in all relevant compartments for acquired immunity. Efforts to tackle this problem link the regulation of transcription or protein activity to the prediction of vaccination outcomes in silico immune system simulator C-ImmSim In silico experiments simulate primary immune responses as well as challenge with a particular antigen in different definable MHC allele backgrounds. The proof-of-principle was performed with antigens of HIV or influenza virus that simulate immunization. The simulations could indeed predict observations in humans, for example that affinity maturation and antigenic dominance evolve, and that MHC diversity can have an impact on immune defense A quite different approach to predict immune responses upon exposure to potential immunogens is realized by the A prevalent problem in vaccine translation is the delayed and costly transition from preclinical to clinical development due to difficulties in predicting human immune responses. Although closer to humans, primate models are associated with ethical, logistic, and financial constraints. An emerging alternative is the use of mice humanized for the immune system. Although they still need to be improved, they can be foreseen as powerful tools to predict human-specific immune responses to vaccines, as well as to investigate vaccine efficacy against pathogens with human tropism In this review we elaborate on recent achievements that facilitate rational vaccine design. There are many visions on the expected impact of reverse vaccinology, epitope prediction, structural vaccinology, systems vaccinology, and personalized medicine on the rational design of effective vaccines Implementation of rational development concepts in vaccinology demands patience, and advances will be incremental. Realization will depend on the application of flanking logistic and regulatory measures and the awareness of the strong impact of vaccine development to solve global health problems. Funding is also required for the basic research needed to provide the basis for rationally developed vaccines. However, we expect to see the advent of new and more efficient vaccines in the coming years as a result of the implementation of this emerging knowledge and enabling technologies.


Cash payments to vulnerable households and/or individuals have increasingly garnered attention as a means to reduce poverty, improve health and achieve other development-related outcomes. Recent evidence from Malawi and Tanzania suggests that cash transfers can impact HIV-related behaviours and outcomes and, therefore, could serve as an important addition to HIV prevention efforts.This article reviews the current evidence on cash transfers for HIV prevention and suggests unresolved questions for further research. Gaps include (1) understanding more about the mechanisms and pathways through which cash transfers affect HIV-related outcomes; (2) addressing key operational questions, including the potential feasibility and the costs and benefits of different models of transfers and conditionality; and (3) evaluating and enhancing the wider impacts of cash transfers on health and development.Ongoing and future studies should build on current findings to unpack unresolved questions and to collect additional evidence on the multiple impacts of transfers in different settings. Furthermore, in order to address questions on sustainability, cash transfer programmes need to be integrated with other sectors and programmes that address structural factors such as education and programming to promote gender equality and address HIV. Cash payments to individuals and households have increasingly garnered attention as a means to reduce poverty and achieve other social goals, such as improved health and education. The trend towards using cash as a health and development strategy first began in Latin America, where transfers became popular in the 1990s as a social protection mechanism and as a vehicle to encourage behaviours such as immunizing children and ensuring they attend school . These tMore recently, interest in cash transfers has spread to sub-Saharan Africa, with 37 countries in 2010 hosting either government-sponsored programmes or pilot initiatives sponsored by donors . Unlike Evaluation research suggests that under certain conditions, cash transfers can significantly increase household consumption, reduce poverty and food insecurity, increase school enrolment and retention and improve health and nutritional outcomes ,5. In hiCash transfers have recently been explored as a potentially important component of a comprehensive HIV response ,13. ApplThe purpose of this commentary is to outline the theory that underpins the use of cash transfers, discuss the evidence of cash transfers’ impacts on HIV-related outcomes and discuss gaps for future research.Two theoretical perspectives underpin the use of cash transfers as a mechanism of social policy. The first focuses broadly on poverty reduction, with conditionality, if applied, being used to encourage behaviours that have social benefits. Here cash payments are intended to improve structural factors, such as the socio-economic situation of vulnerable groups, and to promote social goods, such as school attendance or childhood immunizations . The secRecent experimentation on using cash transfers for HIV prevention mirrors these two theoretical approaches. One set of studies explores the potential of cash transfers to affect HIV vulnerability indirectly by addressing structural sources of risk (“upstream factors”). In the short term, for example, direct cash payments may improve household living conditions, thereby reducing poverty-related stress and decreasing the likelihood that girls or women will resort to transactional sex to obtain food or other goods . Adding A second set of experiments, based on the CM theory, links conditionality directly to HIV-related outcomes (such as collecting HIV test results or maintaining HIV status). For HIV, people have to balance the long-term costs of adopting behaviours that decrease their HIV risk with the short-term benefits of not doing so . Although a purely “rational” assessment should encourage people to be cautious and avoid risky sexual encounters, some individuals will underestimate future risk or give strong preference to immediate gratification over longer term, less certain negative consequences .The wisdom and ethics of using cash transfers, especially CCTs, as a public health strategy are hotly debated ,24. SomeConditionalities are not just questions of public health and ethics; they may also serve political purposes. In Latin America, many of the social protection schemes that include cash transfers were sold to a reluctant middle class by emphasizing the health and educational requirements that accompanied the cash transfer. Conditionality helped increase public support by countering notions that transfers are welfare hand-outs that threaten to undermine personal responsibility and initiative .et al.  . By linkOther evaluation studies are attempting to demonstrate that transfers can affect HIV-related behaviours without targeting HIV directly. In the Zomba cash transfer trial in Malawi, for example, adolescent girls and their households were given monthly cash stipends of varying amounts. Some girls received unconditional stipends, while others received stipends conditional on school attendance. Schoolgirls who received monthly cash payments were significantly less likely than girls who did not receive payments to be infected with HIV  or herpes simplex virus-2 (HSV-2)  in the short term . The impWith a 64% relative reduction in HIV prevalence, the Zomba trial offers some exciting possibilities; nonetheless, it is likely that cash transfers will need to be paired with other structural and HIV-specific interventions to have a sustained, population-level impact on HIV. The Zomba trial, for example, did not increase condom use and did not include activities designed directly to empower girls or to strengthen their HIV-related knowledge and skills . MoreoveThese findings represent the start of an important evidence base, but many unanswered questions remain. Further research is needed to help address three broad categories of questions: (1) What are the mechanisms and pathways through which cash transfers affect HIV-related outcomes, (2) what key operational and programmatic questions remain unresolved and (3) how can one evaluate the wider impacts of cash transfers on health and development?Studies suggest that cash transfers work through many mechanisms and pathways. For example, was the impact of the Zomba trial driven by keeping girls in school, decreasing the number of sexual partners, changing the composition of sexual networks and/or decreasing the frequency of unprotected sex? Does the pathway vary by context  and/or by population (e.g. girls vs. boys at certain ages and income levels)? A better understanding of pathways and how they are affected by context would help to inform where and under what conditions cash transfers may be an effective part of HIV programme.Despite often being presented as an empowering intervention for women, the actual impacts of cash transfers on women's agency and household gender dynamics remain to be tested . It is yAlthough much attention has been paid to the value of economic incentives as behavioural motivators, in practise, the HIV impacts shown in the Zomba trial were achieved in both the conditioned and non-conditioned arm of the trial. Given that incentive-based schemes are costly to maintain and difficult to implement and enforce well , are theWhilst targeting the most vulnerable maximizes potential impact, it can be costly. Operational research is needed to determine the trade-off of targeting only those most in need versus wider groups. The size of transfer needed to achieve the desired benefit is also open to investigation. Tiered payment structures in existing trials show non-linear responses, which suggests that optimizing transfer size is crucial. Cash transfers need to be expensive enough to generate an effect, but can run the risk of being more expensive than they need to be; thus, costing out such programmes is essential.The potential for cash transfers to create perverse incentives or infringe on human rights is still being explored. For example, there is some evidence suggesting that CCTs might have resulted in an increase in fertility of 2–4 percentage points in Honduras because only pregnant women were eligible for the subsidy . SimilarCurrent evidence comes from settings with high HIV prevalence among women and adolescent girls in the general population. Are there other settings where such interventions could be important ? How do the benefits of cash transfers compare to those of other forms of economic or poverty reduction programme?To be delivered at scale, it is likely that cash transfer programmes will need to be integrated into national social protection mechanisms. CCT programmes in Latin America were almost entirely initiated by governments as part of wider poverty reduction schemes. In contrast, many cash transfer programmes  in sub-Saharan Africa have been delivered and financed outside of government at a relatively small scale . In the Most cash transfers for HIV prevention have been evaluated over relatively short time frames. It is thus unclear how long any protective effect may last and whether protection is contingent on a continued incentive, either to the same cohorts as they age or to new cohorts as they become eligible. For example, an analysis of the RESPECT study found that 1 year after cash incentives to stay STI free were removed, the intervention impact had been sustained among men, but not among women. This suggests that for men, the provision of a short-term incentive led to longer term behaviour change, whilst for women, the behaviour was not sustained .Cash transfers, like many structural interventions, have multiple potential impacts above and beyond HIV. Yet, a lot of research occurs in silos, missing opportunities to capture a wide array of downstream impacts. Where appropriate, HIV and health research should capture broader health, social, economic and environmental impacts of interventions. Similarly, upstream development interventions, in areas such as poverty reduction, should examine impacts on HIV and health. Multiple, cross-sector impacts are among the key benefits of structural interventions, and demonstrating such impacts is important for their consideration by policy makers.Silos extend to policy and programmes as well. Although there is often substantial potential to achieve HIV and development synergies, these are not always sought. Integrating HIV and health components into existing cash transfer schemes would expand the impact of these programmes without creating expensive new projects whose costs are borne by HIV donors or the health sector alone. For cross-sector collaboration to work, specific mechanisms and structures are required to bring together relevant, multidisciplinary teams. HIV and health experts must work across silos to help social protection managers understand how to design, monitor and evaluate the programmes for HIV and health-related impacts.Cash transfers are but one mechanism in a range of social protection options that governments employ. All such programmes – from insurance to employment schemes – hold the potential either to benefit HIV-affected individuals and families or to promote risky behaviours. Of particular concern, for example, are the impacts of large public works programmes that put large sums of cash – delivered in set instalments – into men's hands. While alleviating poverty, such programmes might also increase risky behaviours by encouraging binge drinking and commercial sex as men take advantage of their newfound cash. Further research is needed to understand the potential negative consequences of such programmes. Programme designers and evaluators should consider the impacts of these other social protection mechanisms and income schemes on HIV-related outcomes.Traditionally, the cost effectiveness of interventions is assessed against a single development outcome – the project's effectiveness at reducing unwanted pregnancy, for example, or reducing risk of contracting malaria. But, as noted in this article, the benefit of structural interventions is that they yield multiple benefits across various development outcomes. A challenge moving forward is how to capture these multiple benefits and encourage co-financing across sectors. If a cash transfer yields HIV and education benefits, for example, it may be appropriate for some programme costs to be shared between HIV dollars and the education sector. Even if a conditionality is not necessary for HIV benefits, but it is critical for education, the conditionality may still be useful to ensure maximum co-financing across sectors. Doing so might make the economic case for implementing the cash transfer scheme, perhaps at less cost to HIV-specific budgets. Recent analysis of the cost and benefits of the Zomba trial, for example, demonstrates that even a programme that is not cost effective when assessed by traditional means can be very cost effective when analyzed using co-financing models .Despite increasing evidence of their importance, cash transfers are by no means a simple solution to addressing HIV vulnerability. The history of the AIDS epidemic has repeatedly shown that even breakthrough prevention strategies, if used in isolation, cannot halt the epidemic. Rather, new approaches, if used in effective combinations and in the right contexts, can bend the epidemic's curve.The emerging evidence suggests that cash transfers could be an important addition to HIV prevention efforts. Ongoing and future studies should unpack unresolved questions and collect additional evidence on the multiple impacts of transfers in different settings. To ensure sustained impact on HIV, cash transfer programmes need to be integrated with other sector programmes that address structural factors such as education and programming to promote gender equality .


Early recognition and rapid initiation of infection control precautions are currently the most important strategies for controlling severe acute respiratory syndrome (SARS). No rapid diagnostic tests currently exist that can rule out SARS among patients with febrile respiratory illnesses. Clinical features alone cannot with certainty distinguish SARS from other respiratory illnesses rapidly enough to inform early management decisions. A balanced approach to screening that allows early recognition of SARS without unnecessary isolation of patients with other respiratory illnesses will require clinicians not only to look for suggestive clinical features but also to routinely seek epidemiologic clues suggestive of SARS coronavirus exposure. Key epidemiologic risk factors include 1) exposure to settings where SARS activity is suspected or documented, or 2) in the absence of such exposure, epidemiologic linkage to other persons with pneumonia , or 3) exposure to healthcare settings. When combined with clinical findings, these epidemiologic features provide a possible strategic framework for early recognition of SARS. In November 2002, clusters of a highly transmissible and severe atypical pneumonia began appearing among residents of the Guangdong Province of China. These patients are now believed to have been the first persons with severe acute respiratory syndrome (SARS), a previously undescribed respiratory illness now known to be caused by a novel coronavirus (SARS-CoV)  of the chest appears to be more sensitive than conventional chest radiography for detecting pneumonia; SARS patients who have normal chest radiographic findings early in their clinical course often have evidence of pneumonia by CT  respiratory illnesses. Many of the clinical and laboratory features of SARS are similar to those in other forms of viral pneumonia .The main laboratory tests available to diagnose SARS-CoV infection are RNA detection through reverse transcriptase-polymerase chain reaction (RT-PCR) or real-time PCR and serologic testing for antibodies against SARS-CoV  unexplained severe pneumonia and 2) epidemiologic evidence that could suggest SARS, including a link to a cluster of cases of unexplained pneumonia, a history of recent travel (or close contact to an ill traveler) to a previously SARS-affected area, or employment as a healthcare worker with direct patient care responsibilities . For per,In the absence of pneumonia, history of travel to a previously SARS-affected area is likely to have an extremely low positive predictive value for detecting SARS among patients with respiratory illness and, if used as a screening tool, would likely result in an unacceptable burden on the public health system. .The only currently available laboratory method for excluding the diagnosis of SARS-CoV infection is to obtain a negative result on serologic testing of a convalescent-phase serum sample obtained >28 days after onset of symptoms. For patients without evidence of pneumonia at the initial evaluation, serial observations over time may be helpful in identifying those in whom isolation precautions can be safely discontinued  through clinician reports of patients with risk factors for SARS.http://www.cdc.gov and URL: http://www.who.int).Similarly, communication among health authorities in different jurisdictions in a region and among countries around the world will be essential to assess risk for exposure for travelers returning from those areas. Information on SARS can be obtained from CDC and WHO Web sites, among others , exposure to settings in which SARS activity is suspected or documented, and pneumonia among healthcare workers with direct patient care. Surveillance and additional research will be critical to help refine the epidemiologic, clinical, and laboratory features used to identify future infections with SARS, which will in turn help with the early detection and prevention of transmission of SARS-CoV infections.


Dear Editor,We read the interesting study by Szymczak et al.  regardinIt has recently been reported  that patients with typical laboratory features of autoimmune hepatitis (AIH) rarely need a liver biopsy for their diagnosis and moreover, that most patients with hallmark features of AIH are likely to have a compatible liver histology. In the few patients with atypical histology, these findings also have little impact on their clinical management. Thus, a biopsy might be unnecessary in patients who meet the clinical criteria for AIH. This statement might be considered controversial, particularly in those patients who are difficult to categorize due to an atypical clinical presentation. Diagnosing drug-induced liver injury relies primarily on careful history taking; nevertheless, we had the opportunity to study two illustrative cases of patients with acute flares of severe hepatitis that underwent ultrasound-guided liver biopsy for diagnostic characterization. In these patients the histological findings played a decisive role in determining the specific therapeutic intervention required, which subsequently led to a remission of the acute disease .It is generally accepted that a liver biopsy in patients with chronic hepatitis B is indicated in order to prescribe antiviral therapy, this is usually when serum ALT is very low and in suspected cases of advanced fibrosis (> F2) who are at risk of developing cirrhosis. Concerning chronic hepatitis C, a liver biopsy was previously recommended prior to commencing therapy in order to determine whether treatment was warranted and to assess disease prognosis (grading and staging). In current clinical practice this postulation has been revised and now the main role of a biopsy is the objective quantification of liver fibrosis into meaningful clinical groups, in particular, those at risk of progression to cirrhosis. Additionally, histological analysis in chronic viral hepatitis could tentatively include molecular analysis such as in situ hybridization or polymerase chain reaction used to detect occult viral infections, identification of premalignant lesions or in the context of clinical and research protocols 5]..5].In summary, Szymczak et al.  confirme


Aedes spp., DV is increasingly becoming a global problem. Infected individuals may present with a wide spectrum of symptoms, spanning from a mild febrile to a life-threatening illness, which may include thrombocytopenia, leucopenia, hepatomegaly, hemorrhaging, plasma leakage and shock. Deciphering the underlining mechanisms responsible for these symptoms has been hindered by the limited availability of animal models that can induce classic human pathology. Currently, several permissive non-human primate (NHP) species and mouse breeds susceptible to adapted DV strains are available. Though virus replication occurs in these animals, none of them recapitulate the cardinal features of human symptomatology, with disease only occasionally observed in NHPs. Recently our group established a DV serotype 2 intravenous infection model with the Indian rhesus macaque, which reliably produced cutaneous hemorrhages after primary virus exposure. Further manipulation of experimental parameters  can refine this model and expand its relevance to human DF. Future goals include applying this model to elucidate the role of pre-existing immunity upon secondary infection and immunopathogenesis. Of note, virus titers in primates in vivo and in vitro, even with our model, have been consistently 1000-fold lower than those found in humans. We submit that an improved model, capable of demonstrating severe pathogenesis may only be achieved with higher virus loads. Nonetheless, our DV coagulopathy disease model is valuable for the study of select pathomechanisms and testing DV drug and vaccine candidates.Dengue Virus (DV) infects between 50 and 100 million people globally, with public health costs totaling in the billions. It is the causative agent of dengue fever (DF) and dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), vector-borne diseases that initially predominated in the tropics. Due to the expansion of its mosquito vector,  Aedes albopictus and Aedes aegypti , the causative agent of dengue fever (DF), is the most important vector-borne human pathogen, infecting between 50 and 100 million people annually Who, . Moreovepti Who, . Thanks The majority of DV infections are asymptomatic or mild, but for about a quarter of infected people, disease may present as an illness that is indistinguishable from other febrile diseases or as DF with minor hemorrhagic abnormalities, bone pain, decreases in platelet counts and leucopenia, the most common form of disease. Rarely, people present with the severe forms—dengue hemorrhagic fever (DHF) in which patients display hematomas with a marked thrombocytopenia or extremely low platelet counts and dengue shock syndrome (DSS), a disease similar to DHF but including plasma leakage/heme concentration, pleural effusion and the increased risk of multi-organ failure  responsible for disease pathogenesis; this was done by selecting for candidates that reduced viremia and elicited strong antibody responses Cox, . UnfortuA more thorough understanding of the mechanisms contributing to disease and protection in humans is clearly needed to accelerate progress toward better drug and vaccine candidates. Severe disease is known to arise after the clearance of viremia, suggesting that DHF/DSS and lethality are more likely immune than viral-mediated  ever displayed signs of disease, limiting the progress in studying DV  displayed evidence of subcutaneous hemorrhage  , which was markedly elevated on Day 7  in primates were conducted with human-derived virus that had never been propagated through cell culture  may ensure that the strain is more fit for these studies. It has been suggested that mouse-passaged viruses are more capable at causing viremia in NHPs than in vitro-passaged strains  and S16803 (DV2) caused extreme lethargy in owl monkeys . However, no difference was noted in virus growth kinetics or magnitude related to age of BM donors (n = 11), which spanned 2–15 years of age. In vivo, anecdotal observations suggested that coagulopathy appeared to be more extensive in older female macaques when compared to young males, which were the populations included in the study, although sample size was too low to be conclusive. This nevertheless raises an interesting question about the potential for host factors contributing to the severity of symptoms.Epidemiological studies of dengue patient characteristics, including age, sex and genetic polymorphisms have been frequently studied, but none of these findings have been validated in animal models (Loke et al., HPA1, HPA2 for association with disease presentation. Available techniques, such as Macaca mulatta typing and gene expression analyses, will need to be an integral part of future experiments with the rhesus monkey model to facilitate identification of genetic factors involved with dengue-induced abnormal coagulation.Various MHC alleles, blood group and platelet antigens have been found to be associated with dengue disease and protection (Kalayanarooj et al., in vivo. Various host and viral parameters can begin to be evaluated in vivo to help us gain a better understanding of dengue biology and disease pathogenesis. Can pathology be induced in other NHPs by switching to the intravenous route? Will different virus strains promote coagulopathy, or other symptoms? Can we alter other parameters and achieve a more severe disease model? The establishment of this new rhesus macaque infection model has proved insightful on ways to improve disease presentation in primates.The induction of disease symptoms upon the inoculation of DV in primates has been an elusive objective. Recently a coagulopathy disease model was developed using the serotype 2 strain 16681 injected intravenously into Indian rhesus macaques. We submit that this approach provides a strategy for detailed investigation of the mechanisms potentially involved in DHF. Moreover, the model provides an attractive algorithm for testing the efficacy of preventative vaccines and therapeutics that not only limit virus replication but also prevent disease development Use of deidentified human BM was provided by Emory Hospital and approved by the Emory University Internal Review Board. Investigations with rhesus macaques were approved by Yerkes and Tulane IACUCs and conducted at either the Yerkes or Tulane National Primate Research Centers. Research was performed in accordance with institutional and national guidelines and regulations.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Excess dietary fat consumption is recognized as a strong contributing factor in the development of overweight and obesity. Understanding why some individuals are better than others at regulating fat intake will become increasingly important and emerging associative evidence implicates attenuated fatty acid sensing in both the oral cavity and gastrointestinal (GI) tract in the development of obesity. Functional implications of impaired fatty acid chemoreception include diminished activation of the gustatory system, the cephalic response and satiety. This review will focus on knowledge from animal and human studies supporting the existence of oral fatty acid chemoreception including putative oral detection mechanisms, and how sensitivity to fatty acids is associated with fat consumption and fatty food preference.  Obesity is one of the leading causes of preventable disease contributing to negative health outcomes including cardiovascular disease, type-2 diabetes and cancer ,2. It isThe global rise in overweight and obesity is a worldwide health concern and in some regions, has taken the lead over tobacco as the largest preventable cause of disease burden . There hThere are many factors which contribute to weight gain and the consequential increase in the prevalence of overweight and obesity, including the wide availability of cheap, energy-dense foods . These tTaste is a sense that utilizes chemoreception to detect non-volatile chemicals in potential foods . It is hA taste quality is experienced when the concentration in the oral cavity reaches a level that activates a receptor, which in turn elicits a perception . For exa+ channel which may be involved in taste cell homeostasis, and ionic currents which may be involved in the perception of salty taste ..17].CD36 receptor plays a direct role in fat perception, and possibly food regulation [One of the proposed mechanisms of oral fatty acid nutrient detection is via CD36, a FAT . CD36 isgulation ,36.et al. [CD36 receptor, oral fat perception and fat preference in human subjects. These types of physiological signals which detect fat, and control consumption are plausible and these mechanisms should be explored further.A recent study using obese humans investigated whether oral sensitivity to fatty acids is attenuated when expression of CD36 is reduced . Subjectet al. , has sugThe possibility that GPCRs may be involved in fatty acid detection in the oral cavity has been suggested and it is thought that CD36 may work together with other possible receptors like GPCRs in a signaling cascade to detect fatty acids . GPCR120DRK channels are known to be implicated in the transduction pathway of a variety of taste stimuli. A study by Gilbertson  found thThe breakdown products of carbohydrates are sugars and proteins are amino acids both of which have taste activity . TherefoThere are multiple putative mechanisms to initiate oral fatty acid detectors including CD36 transporter, FAT, GPCRs, DRK channels and lingual lipase hydrolysis of fats to fatty acids; however it is yet to be elucidated if/how these function independently or together in oral fatty acid detection.vice versa.Recent research has implicated oral fatty acid sensitivity in weight gain, with those less sensitive (higher taste threshold) having a higher body mass index (BMI) ,44. Oralet al. [Kamphuis et al.  investiget al. ,63. Neveet al. [The relationship between oral fatty acid sensitivity, BMI and dietary fat intake has recently been investigated by our group . It was et al.  extendedet al. . The exaAn important mechanism involved in energy intake regulation is the body’s ability to detect fat and other nutrients in the oral cavity and GI tract. Evidence now exists indicating that sweet and umami taste receptors for sugars (carbohydrates) and amino acids (proteins) respectively, are co-located in the GI tract , which pDuring digestion, fats have potent effects on hormones that regulate food intake, for example, CCK and glucagon-like peptide-1 (GLP-1) decrease gastric emptying and secretion of the hunger stimulating hormone ghrelin, while leptin binds to neuropeptide Y (NPY) to reduce appetite and induce satiety in a lean individual ,64. StudConsumption of a high fat diet has been shown to decrease oral fatty acid sensitivity . DietaryAs previously mentioned, fats are thought to be detected by fatty acid specific receptors in both the oral cavity and GI tract. The role of these receptors in fat detection is now becoming more apparent with studies highlighting dietary influences on receptor expression. While there is a paucity of evidence in humans, emerging evidence in animals is showing promising findings. Following the consumption of a high fat diet, CD36 receptor expression on the lingual tissue of rats was reduced highlighting the potential link between fat consumption and CD36 receptor expression . While svice versa. Knowing the reproducibility and stability of an individual’s oral sensitivity is important and needs to be verified. Oral fatty acid sensitivity and its potential links to obesity is a controversial area of research with more investigation needed from a variety of scientific disciplines, but emerging evidence linking oral fatty acid sensitivity with development of obesity is promising. Currently the exact mechanisms associating oral fatty acid sensitivity, fat consumption and weight gain remain largely elusive. Dietary intake may not be the only factor influencing one’s sensitivity; other considerations, for example the expression of taste receptors in the oral cavity are likely to play an influential role. Investigating oral fatty acid sensitivity and its potential links with dietary fat intake and putative fatty acid taste receptor expression will build upon present knowledge; if indeed receptor expression can be modulated in response to a high fat diet, or if expression is a driver of fat preference and consequent consumption may provide more of an insight into reasons for excess fat consumption. These ideas are conjectural, but may identify strategies to reduce obesity and related pathologies.In summary, excess fat consumption is a major cause of obesity as well as other diseases including CVD and type-2 diabetes. Fat intake can be influenced by many factors including habituation and satiety mechanisms and an individual’s ability to detect fatty acids in the oral cavity and GI tract via fat specific receptors. There is substantive emerging evidence that an oral nutrient detection system for fatty acids exists in humans. Similarly to the five basic tastes, the ability to detect fatty acids in the oral cavity varies amongst the population. This variance may be a factor in influencing one’s consumption of high-fat foods, with those who are hypersensitive consuming less fat, and preferring low-fat foods than hyposensitive individuals who consume more fat and prefer high-fat foods. It is unknown what the main drivers of this concept are, or if in fact reduced fatty acid sensitivity is a predictor of dietary fat consumption, or


PLOS Genetics, Bauer et al. provide a remarkable answer to these questions by demonstrating that condensin II, one of the major chromosome condensation factors in mitosis In human diploid cells, 23 pairs of chromosomes become recognizable as a discrete set of rod-shaped entities during the mitotic stage of the cell cycle. Upon exit from mitosis, they decondense and are packed together into the nucleus, in which individual chromosomes are no longer discernible. Nonetheless, evidence accumulated during past decades suggests that the decondensed chromosomes are not randomly located within the nucleus, but instead occupy distinct subnuclear domains known as chromosome territories (CTs) Drosophila melanogaster, which display a highly characteristic mode of chromosome organization and dynamics. The chromosomes in these cells are amplified by repeated rounds of DNA replication without intervening mitoses , giving rise to polytene chromosomes in which many copies of homologous chromosomes and chromatids are paired along their entire lengths. After the fifth cycle of endoduplication, however, the pairing of homologous chromatids is disrupted, allowing each set of chromosome arms to occupy a discrete globular territory that is reminiscent of a CT observed in mammalian cells. A previous study from the same group demonstrated that condensin II function is required for the disassembly of polytene chromosomes occurring at this stage To address the question of how interphase chromosomes might be organized, the authors focused on nurse cells in the ovary of the fruit fly Why, then, do chromosomes fail to form CTs when condensin II function is impaired? An extensive set of fluorescence in situ hybridization (FISH) data suggested that condensin II promotes not only axial compaction of chromosomes, but also dispersal of heterologous centromeres. Importantly, the dispersed pericentromeric heterochromatin nonetheless stayed near the nuclear periphery. Conversely, when one of the condensin II–specific subunits (Cap-H2) was overexpressed in salivary glands, their polytene chromosomes were disassembled, leading to axial shortening of chromosomes and CT formation. Based on these data, the authors propose a simple and appealing model in which the combination of two events, condensin II–mediated axial compaction and sustained interactions of heterochromatic regions with the nuclear periphery, drives each chromosome into a globular CT . They alDrosophila, unlike in other metazoans, homologous chromosomes are always paired in virtually all types of cells throughout development. It has long been known that the pairing of homologous chromosomes affects gene expression at a number of loci through a process known as transvection Drosophila tissue culture cells Although this is an interesting and plausible model, one could ask to what extent the insights obtained from the highly specialized polytene nuclei might be applicable to diploid nuclei. In cis  and those in trans  compete with each other. Interestingly, a similar principle has already been put forward to delineate the dynamic interaction between sister chromatids within a duplicated chromosome. Upon entry into mitosis, bulk cohesin is lost from chromatid arms, and condensin II coincidentally initiates intrachromatid folding. As a consequence, sister–sister interactions are loosened, leading to the formation of metaphase chromosomes in which rod-shaped sister chromatids are juxtaposed along their lengths, a process known as sister chromatid resolution Xenopus laevis egg extracts has demonstrated that this process is indeed controlled by an intricate balance between the cohesin-mediated cohesive forces and condensin II–mediated resolving forces Xenopus egg extracts The outcome of these emerging studies strongly implies that chromosome–chromosome interactions in Drosophila interphase nuclei In summary, a unique and powerful experimental system, combined with a labor-intensive assay, enabled Bauer et al. to propose a model of how CTs might be formed in


Adult skeletal muscle possesses a remarkable regenerative ability that is dependent on satellite cells. However, skeletal muscle is replaced by fatty and fibrous connective tissue in several pathological conditions. Fatty and fibrous connective tissue becomes a major cause of muscle weakness and leads to further impairment of muscle function. Because the occurrence of fatty and fibrous connective tissue is usually associated with severe destruction of muscle, the idea that dysregulation of the fate switch in satellite cells may underlie this pathological change has emerged. However, recent studies identified nonmyogenic mesenchymal progenitors in skeletal muscle and revealed that fatty and fibrous connective tissue originates from these progenitors. Later, these progenitors were also demonstrated to be the major contributor to heterotopic ossification in skeletal muscle. Because nonmyogenic mesenchymal progenitors represent a distinct cell population from satellite cells, targeting these progenitors could be an ideal therapeutic strategy that specifically prevents pathological changes of skeletal muscle, while preserving satellite cell-dependent regeneration. In addition to their roles in pathogenesis of skeletal muscle, nonmyogenic mesenchymal progenitors may play a vital role in muscle regeneration by regulating satellite cell behavior. Conversely, muscle cells appear to regulate behavior of nonmyogenic mesenchymal progenitors. Thus, these cells regulate each other reciprocally and a proper balance between them is a key determinant of muscle integrity. Furthermore, nonmyogenic mesenchymal progenitors have been shown to maintain muscle mass in a steady homeostatic condition. Understanding the nature of nonmyogenic mesenchymal progenitors will provide valuable insight into the pathophysiology of skeletal muscle. In this review, we focus on nonmyogenic mesenchymal progenitors and discuss their roles in muscle pathogenesis, regeneration, and homeostasis. The most fundamental roles of skeletal muscle are the generation of force and the control of body movement by contraction. In addition, skeletal muscle serves as physical safeguard for other organs as it is anatomically located immediately beneath the skin. Because of its functional roles, skeletal muscle represents one of the most frequently damaged organs in the body. Therefore, regeneration from the damage is an essential property of skeletal muscle. One of the best examples of remarkable regeneration capacity of skeletal muscle is the study that showed myofiber regeneration after more than 20 repeated injuries  components, which can lead to permanent scarring and organ malfunction. Although ECM deposition is an indispensable and, typically, reversible part of wound healing, the repair process can produce a progressively irreversible fibrosis if the tissue injury is severe or repetitive or if there is a defect in the repair machinery. Fibrosis in skeletal muscle can be seen in most conditions where there is chronic muscle damage or insufficient regeneration but is most prominent in muscular dystrophy  is defined as the abnormal formation of mature, lamellar bone in soft tissues outside the skeletal periosteum. The most commonly affected site is skeletal muscle. HO has been thought to result from inappropriate differentiation of progenitor cells that is induced by a pathological imbalance of local or systemic factors. There are three recognized etiologies of HO: traumatic, neurogenic, and genetic , because these cells have the potential to produce both adipocytes and fibroblasts but fail to differentiate into osteogenic cells in vitro. PDGFRα+ mesenchymal progenitors express Sca-1, and complementally FAPs express PDGFRα  and laminin α2 expression and a transient increase in atrogin-1 and MuRF1 mRNA levels. Fst is an inhibitor of myostatin (Mstn), a negative regulator of muscle mass -expressing stromal cells  or mesenchymal progenitors were initially identified in bone marrow. Due to the ease of their isolation and their extensive proliferation and differentiation potentials, bone marrow MSCs have been expected as a source of cells for potential use in cell-based therapy and are being introduced into a clinical setting . Although several cell types in bone marrow are suggested to play a role in forming the HSC niche , a c-kit ligand, is required to sustain hematopoiesis. Cxcl12 is produced mainly by reticular cells scattered throughout the bone marrow, and these reticular cells were termed Cxcl12-abundant reticular (CAR) cells –expressing perivascular stromal cells were shown to be one of the major sources of Scf and required to maintain HSCs (Ding et al., Lepr+ cells was not examined. The Cxcl12 gene was knocked out conditionally using several Cre lines to clarify the importance of Cxcl12 expression in several different candidate niche cells (Greenbaum et al., +Sca-1+ cells in bone marrow (Morikawa et al., +Sca-1+ cells exhibited colony-forming unit-fibroblast activity and showed osteogenic and adipogenic differentiation, indicating that this subset is a highly enriched population of MSCs. Maintenance of committed B cell precursors is dependent on Cxcl12 from CAR cells and/or osteoblasts, and retention of hematopoietic progenitor cells in the bone marrow is dependent on Cxcl12 from CAR cells. These results showed the complexity of the niche microenvironment in the bone marrow and suggest that distinct stromal niche cells regulate specific hematopoietic stem/progenitor populations. Naveiras et al. reported an interesting finding. They showed that adipocyte-rich vertebrae of the mouse tail have reduced HSC frequency compared with adipocyte-free vertebrae of the thorax (Naveiras et al., +CD51+ cells in human bone marrow represent a cell population enriched for MSCs and capable of expanding human hematopoietic stem and progenitor cells. These lines of evidence suggest that the intrinsic function of MSCs in bone marrow is to act as a niche for HSCs.Several recent studies documented in vitro multipotency toward adipogenic, osteogenic, and chondrogenic lineages is a hallmark of MSCs, there is no evidence that fat, bone, or cartilage are continuously generated in most organs where MSCs reside. Therefore, it seems unlikely that differentiating into a certain lineage is an intrinsic in vivo function of MSCs. Instead, it is tempting to speculate that these cells exert support functions for parenchymal cells of the tissue where they reside, as reviewed in this paper. Their differentiation might be undesired in most cases because adipogenic differentiation has a negative impact on hematopoiesis in bone marrow (Naveiras et al., Mesenchymal stem/progenitor cells are reported to exist in almost all organs of both mice and humans (Da Silva Meirelles et al., The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Stiffness change of tissue is often seen with the progression of pathology. In the past two decades, ultrasonic elastography has emerged as a powerful complementary technique to B-mode ultrasonic imaging, in which strain of target tissues can be imaged and their stiffness can be assessed. The physical principle of elastography is, when deformation is generated in the tissue by an external or internal mechanical stimulus, coherent acoustic echoes can be tracked by a pulse-echo system, then induced strain inside the tissue can be estimated and the relative mapping of strain can be imaged. In addition, the viscoelastic properties of the tissue can be assessed if the mechanical wave velocity propagating in the tissue was measured. Now this technique has been developed to be more flexible and accurate. The qualitative results presented by quasi-static elastogram have changed to numerical quantification of viscoelastic modulus achieved by other innovative methods, such as sonoelastography, transient elastography, acoustic radiation force impulse imaging (ARFI), shear-wave dispersion ultrasound vibrometry (SDUV) and supersonic shear imaging (SSI). Aiming for different tissue or organs, these methods can achieve viscoelasticity assessments on various target objects with sizes from tens of millimeters to several microns. Short or trains of mechanical or acoustic radiation force impacts have been used to generate displacements with different patterns. The induced deformation in the tissue has also been tracked by different algorithms based on both cross-correlation and texture matching approaches. Some of these techniques have been studied by our group, and the combination of ultrasonic elastography and particle imaging velocimetry (PIV) using microbubble contrast agents has been also explored. Ultrasonic elastography has been verified on many normal/abnormal tissues and now widely used in clinical practice, such as on breast disease , liver fibrosis and cirrhosis, dermatology (melanomas and scars), cardiovascular disease (cardiac muscle disease and arteriosclerosis), musculoskeletal studies, minimally invasive surgery and hyperthermia therapy (temperature monitoring and lesion detection in HIFU) . During these 20 years, ultrasonic elastography has been developed to be a powerful adjunctive technique to traditional medical imaging methods and expected to become an excellent tool for clinical diagnosis and treatment.