Prior to neuroinvasion, TSE agents often accumulate to high levels within the LRS, apparently without affecting immune function. However, our analysis of scrapie-affected sheep shows that PrPd accumulations within the LRS are associated with morphological changes to follicular dendritic cells (FDCs) and tingible body macrophages (TBMs). Here we examined FDCs and TBMs in the mesenteric lymph nodes (MLNs) of scrapie-affected mice by light and electron microscopy. In MLNs from uninfected mice, FDCs could be morphologically categorised into immature, mature and regressing forms. However, in scrapie-affected MLNs this maturation cycle was adversely affected. FDCs characteristically trap and retain immune complexes on their surfaces, which they display to B-lymphocytes. In scrapie-affected MLNs, some FDCs were found where areas of normal and abnormal immune complex retention occurred side by side. The latter co-localised with PrPd plasmalemmal accumulations. Our data suggest this previously unrecognised morphology represents the initial stage of an abnormal FDC maturation cycle. Alterations to the FDCs included PrPd accumulation, abnormal cell membrane ubiquitin and excess immunoglobulin accumulation. Regressing FDCs, in contrast, appeared to lose their membrane-attached PrPd. Together, these data suggest that TSE infection adversely affects the maturation and regression cycle of FDCs, and that PrPd accumulation is causally linked to the abnormal pathology observed. We therefore support the hypothesis that TSEs cause an abnormality in immune function.Transmissible spongiform encephalopathies (TSEs) or prion diseases are infectious neurological disorders of man and animals, characterised by abnormal disease-associated prion protein (PrP They are characterised by the accumulation of an abnormal post-translationally modified form of the host encoded cell surface glycoprotein - prion protein (PrP), which has been shown to associate with infectivity d at the cell surface following scrapie infection in mice d accumulation in the LRS is associated with morphological change The role of the LRS in the pathogenesis of TSEs has been extensively studied d immunolabelling only on cells morphologically similar to mature FDCs in the light zone of secondary follicles In scrapie-affected hosts, immunolabelling for complement receptors (CR) 2 and 1 , which are expressed on FDC membranes and on B-lymphocytes d labelling of FDCs which are confined to germinal centres of secondary follicles, PrPd labelling of tingible body macrophages (TBMs), so named due to their dark-staining, phagocytosed nuclear remnants in their cytoplasmic vesicles d accumulations are located in lysosomes where PrPd is truncated with the loss of the N-terminal amino acid sequence from approximately codons 23–90, depending on strain and host species, while all other types of PrPd accumulation remain full length Unlike PrPd is associated with the FDC dendrite plasmalemma and TBM lysosomes. PrPd is also present at the TBM plasmalemma in association with uncoated invaginations. Scrapie-affected sheep demonstrated two further patterns of PrPd accumulation within tonsils and lymph nodes that were absent from murine scrapie-affected spleens. Mature antibody-producing B-lymphocytes are retained for prolonged periods within secondary follicles following emperipolesis by abnormal FDCs. PrPd accumulations were detected on the plasmalemma of plasmablasts, putatively following passive transfer during FDC/B-lymphocyte immune stimulation, while PrPd was also identified within TBMs at the membrane of random endoplasmic reticulum (ER) networks Sub-cellular morphological studies of spleens from mice terminally-affected by scrapie and lymph nodes from clinically-affected sheep, have demonstrated that FDCs form abnormally convoluted labyrinthine structures, with abnormal accumulations of irregular, excess electron-dense deposits – containing putative immune complexes – between their dendrites d in scrapie-affected murine MLNs and compared these to previous data. Immunolabelling for globulins and ubiquitin was used to assess the relationship between morphological changes and potential changes to FDC function. Our study identifies a previously unrecognised form of FDC which represents the initial stage in abnormal FDC maturation, in addition to subsequent disease-specific alterations to the FDC maturation cycle. We show data which suggests a cyclical pattern of maturation and regression of FDCs, and that regressing FDCs are capable of shedding PrPd. Our data also show that PrPd accumulates on the plasmalemma of abnormal FDCs in addition to either or both abnormal cell membrane ubiquitin and excess Ig. Plasma cells surrounded by PrPd-labelled FDC dendrites are numerous within scrapie-affected follicles. Within secondary follicles, TBMs accumulate PrPd, ubiquitin and Ig within endosomes and lysosomes. These data suggest that TSE infection causes an alteration in the maturation and regression cycle of FDCs and that PrPd accumulation instigates the abnormal pathology observed in both sheep and mouse lymphoid tissue.In the current study, we aimed to determine whether differences previously observed between scrapie-affected lymphoid tissues of sheep and murine spleen were species, tissue or cell specific. Here we have studied the morphological responses and sub-cellular location of PrPAll experiments involving animals carried out within VLA are supervised by a named Veterinary surgeon as required under UK legislation and individual experiments are approved by UK government Home office inspectors.n = 11) were inoculated intracerebrally with either ME720 scrapie brain homogenate (n = 6), or normal brain homogenate (n = 5). Mice were killed by cervical dislocation at 165 dpi, at which time the ME7-infected animals were in the terminal stage of disease. The MLNs of all mice were fixed in a solution containing paraformaldehyde 0.5% and glutaraldehyde 0.5%. Between 22 and 35 cubes (1 mm3) of tissue were taken from each animal. Tissue blocks were post-fixed in osmium tetroxide, dehydrated and embedded in araldite.C57BL/DK mice of either sex,  IgM  and ubiquitin  using the same immunolabelling procedure described above with the omission of the etch and formic acid stages.Immunohistochemistry is commonly used to detect PrPd containing follicles as described previously Ultrathin 65 nm sections were taken from resin blocks found to show PrPData are presented as mean±SD. A two-tailed T-test was performed to compare the average numbers of follicles between uninfected and infected murine lymph nodes. As standard deviations were not similar the Welch correction was applied.d, IgG, IgM and ubiquitin. Within each 1.0 mm2 section an average of four secondary follicles (4±3) containing FDC networks were present within MLN tissue blocks from uninfected control animals, compared to nine follicles (9±5) in scrapie-affected mouse MLN blocks . All mature secondary follicles in tissue blocks from the scrapie-affected mice demonstrated abundant PrPd labelling . However, the morphological features of mature FDCs appeared abnormal when compared to controls . The matIn the present study, a third, previously unrecognised morphological pattern of abnormal mature FDCs was found in scrapie-affected mouse MLNs A. DendrWithin tissues from control mice, Ig immunolabelling was closely associated with the fine line of electron-dense material between the dendritic processes of mature FDCs A. Thesed immunolabelling was present in any control tissues studied, however, within secondary follicles of scrapie-infected MLNs, abundant PrPd was observed upon the plasmalemma of all mature FDC dendrite forms within the germinal centre of the secondary follicle , at a level similar to that observed in compartments of TBMs from normal animals. Intense ubiquitin labelling which appeared to be at a level greater than that of control animals, was restricted to a subset of endosomal structures within TBMs , which can only retain immune complexes to a distance of approximately 0.15 nm from the cell surface , and with the presence of a plateau in TSE agent infectivity levels at approximately 26% of incubation periods in spleens of scrapie-affected mice c expression from scrapie-affected neurons reverses pathology and putatively eliminates infection of neurons c from scrapie-affected FDCs may allow them to shed PrPd and agent infectivity.A previous study has suggested that normal FDCs may mature and regress in a continuous cycle d on the FDC plasmalemma may induce abnormal mono-ubiquitination of linked transmembrane ligands, an effect also observed on neuronal cells d though the present study does not discriminate between species, cell or strain effects.Abundant ubiquitin was abnormally present at the plasmalemma of hypertrophic FDCs which also accumulated excess extra-cellular electron dense deposit or exosomes. Extracellular ubiquitin has been reported in many studies although its function and biological significance remain undefined. When compared with normal levels of ubiquitin, increased levels can be detected in serum or plasma in various diseases d at the FDC cell surface is associated with, and probably causally linked to, changes in immune-complex retention and B-lymphocyte alterations. These changes suggest alterations may occur in the clonal selection, proliferation and the subsequent maturation of B-lymphocyte populations, challenging the current dogma that scrapie infection does not impinge upon the normal function of the immune system. The current lack of reliable TSE-specific preclinical diagnostics compounds the problems for disease treatment and eradication. Detailed characterisation of the disease-specific alterations to immune function will aid the identification of reliable markers for preclinical diagnosis of TSE diseases. Our data also suggest regressing FDCs may cease production of PrPc and as a consequence undergo regression and self–cure. Treatments that block the maturation and function of FDCs have been shown to reduce susceptibility to peripherally-acquired TSE infections. c expression from scrapie-affected neurons reverses CNS pathology c from a scrapie-affected FDC may provide a novel approach for therapeutic intervention.These findings demonstrate that the murine response to scrapie infection in lymph nodes exhibits significant similarities to that demonstrated by ovine lymph nodes. This suggests that scrapie infection results in altered FDC maturation and regression cycles as revealed by morphological changes. Retention of excess disease-associated forms of PrPFigure S1Diagram showing the method used to determine the ratio of intracellular and extracellular ubiquitin at the FDC plasma-membrane. To determine the precise location of ubiquitin at the plasma-membrane of FDCs we performed geometrical calculations (assuming an average membrane thickness of = 9 nm (1.88 MB TIF)Click here for additional data file.Figure S2Plasmalemmal Ubiquitin labelling of FDCs is cell derived. Two electron micrographs showing ubiquitin labelling of a scrapie-affected FDC were analysed. Counts were made of gold particles adjacent to the intracellular and extracellular sides of the plasma-membrane, and of those gold particles deemed to be on the plasma-membrane. Two areas from micrograph 1 were analysed (count 1 and count 2), while three areas from micrograph 2 were studied . These results were compared with hypothesised intracellular ubiquitin signal (HYP1) and the corresponding extracellular signal (HYP 2). We conclude that ubiquitin at the plasma-membrane of FDCs in scrapie-affected mice is produced within the cell itself.(0.52 MB TIF)Click here for additional data file.


Spatial mapping and navigation are figured prominently in the extant literature that describes hippocampal function. The medial entorhinal cortex is likewise attracting increasing interest, insofar as evidence accumulates that this area also contributes to spatial information processing. Here, we discuss recent electrophysiological findings that offer an alternate view of hippocampal and medial entorhinal function. These findings suggest complementary contributions of the hippocampus and medial entorhinal cortex in support of episodic memory, wherein hippocampal networks encode sequences of events that compose temporally and spatially extended episodes, whereas medial entorhinal networks disambiguate overlapping episodes by binding sequential events into distinct memories. Does hippocampal activity embody the cognitive map? One should expect the neural instantiationof Tolman's  cognitivInitially, hippocampal place cells seemed to satisfy key criteria for elements of Tolman'scognitive map. The first complete study characterized place cells as signalingan animal's location in the environment independent of egocentric direction andongoing behavior, as would be expected of the units in an allocentric representation. An expaHowever, even inthe early data there were loose ends. Location related hippocampal neuronalactivity tells us only where the animal is, not where it plans to go, as isTolman's intended function of a cognitive map . SucceedIn sum, placecells do identify where the animal is when important things happen. But placecells do not carry a reliable allocentric signal, and populations of placecells do not operate as a holistic representation of space or anticipate thelocations of goals. Therefore, hippocampal neurons do not have the requisiteproperties to support Tolman's cognitive map. By contrast, the findingsindicate that hippocampal neurons represent events in the places where theyoccur, consistent with current views of hippocampal involvement in episodicmemory e.g., , 39)..39]).The recentdiscovery of spatial firing patterns in the cortex immediately adjacent to thehippocampus has refocused the search for the cognitive map to a zone within themedial entorhinal area , 40–43. The hippocampus isstrongly implicated in spatial memory and navigation as evidenced by bothbehavioral and physiological studies. At the same time, a convergent stream ofbehavioral, physiological, and computational modeling data indicate thathippocampal processing is critical for episodic memory –57.How Currentconceptions of episodic memory emphasize the temporal organization of sequencesof events as they unfold over time and space . RepreseAdditional supportfor sequencing and disambiguation of serial events by hippocampal networkscomes from analyses of hippocampal neuronal activity in animals performingspatial memory tasks. In one study, rats were trained on the classic spatialT-maze alternation task in which successful performance depends ondistinguishing left- and right-turn episodes to guide each subsequent choice. If hippIn order tocorrectly trigger a series of event representations within a particularepisode, the hippocampus requires a mechanism to bind its representations ofevent sequences according to the appropriate episode they compose. Onesuggestion is that sequences are bound by a shared temporal context , 62 and Thus far, allobservations of grid field activity patterns in medial entorhinal cortex arederived from animals foraging in random directions within an open field. Infact, Derdikman et al.  report tIn a recent study,we adopted the same spatial memory task used previously  tocompaWe trained rats toperform the spatial alternation task on a T-maze that included return arms thatconnected the end of each goal arm to the starting end of the central stem. A left-Many of our medialentorhinal neurons that exhibited spatial specificity also exhibiteddifferential firing along the central stem of the maze during left- andright-turn trials, similar to hippocampal neurons . Thepatnp/p, where p is the probability densityfunction of left-turn (L) trials at position x, evaluated at the observedfiring rate r, and p is the equivalent function for right-turn (R) trials [We used a two-wayANOVA and log-likelihood estimation to quantitatively compare the incidence androbustness of trial-type disambiguation in medial entorhinal and hippocampalneurons. Dividing the central stem into seven equal segments, we used a two-wayANOVA to compare the spatial firing patterns on segments of the central stembetween left-turn and right-turn trial types for each cell .We cons) trials . For eac) trials ).P < .003). In other words, firing patterns of medial entorhinal neuronswere on average more distinct on either left- or right-turn trials than werehippocampal neurons.Using the two-wayANOVA, we identified neurons in the hippocampus and medial entorhinal area thatdistinguished trial type as animals traversed the central stem. Based on thetwo-way ANOVA, 56% of medial entorhinal neurons  were significantly more active on either right- or left-turntrials, whereas 33% (16/48) of hippocampal neurons exhibited differentialfiring on the central stem. Moreover, the log-likelihood estimation revealedthat medial entorhinal neurons more robustly distinguished left- fromright-turn trials than did hippocampal neurons, such that the averagelog-likelihood ratio for medial entorhinal neurons was significantly greaterthan for hippocampal neurons . To calculate pchance, we evaluated the following formula: Pnk = n!/k!/(n − k)!(0.5k)0.5k), indicating thatthe activity of medial entorhinal neurons along the central stem moresuccessfully predicted trial type than hippocampal neurons. Correspondingly,the difference in firing among left- and right-turn trials of medial entorhinalneurons was on average less likely to have occurred by chance than that of hippocampalneurons .Again,medial entorhinal neurons had a significantly higher mean While the ANOVA and log-likelihood estimation did not always agree on specific units,together they converged on the same conclusion; just as hippocampal units didnot exclusively encode information about space, medial entorhinal neuronslikewise exhibited location-related firing modulated by mnemonic demands.Furthermore, medial entorhinal neurons performed better than hippocampalneurons at distinguishing trial type on our version of the continuous spatialalternation .2 versus 330.8 cm2,resp.; Wilcoxon rank-sum test, P < .0003). The degree of spatialtuning, or the ratio of firing inside versus outside a place field, forhippocampal neurons was on average significantly higher than for medialentorhinal neurons . The amount of spatial informationconveyed by hippocampal neurons also was significantly greater than that ofmedial entorhinal neurons .Conversely, hippocampal neuronsshowed greater spatial specificity than medial entorhinal neurons, as isevident by directly comparing the spatial firing patterns displayed in FiguresTogether the results of this studysuggest that disambiguation of overlapping experiences occurs prior to thehippocampus, and that hippocampal and medial entorhinal circuits play distinct andcomplementary roles in the continuous spatial alternation. Medial entorhinalneurons more successfully distinguished task related episodes in the context ofleft- versus right-turn trial type, whereas hippocampal neurons provided agreater degree of spatial specificity. Together both regions supply requisiteelements of a neural code for particular events as they occur within uniqueepisodes.Since the neural circuitry amongthese brain regions constitutes a series of loops , it is dOur recent experimental resultsconfirm that medial entorhinal neurons carry a spatial signal. However, asnoted above, most of these neurons do not fire at discrete locations associatedwith particular trial events, as do hippocampal neurons. Instead, many medialentorhinal cells show strong context sensitivity, outperforming hippocampalneurons in distinguishing left-turn and right-turn trials. Furthermore, theprolonged firing periods of medial entorhinal cells are consistent with thecharacterization of context sensitive neurons that could bind a series ofhippocampal representations of punctate events .A growing body of evidencesupports the notion that the medial entorhinal area is part of theparahippocampal region that processes contextual representations. This evidenceis derived from knowledge about the anatomical pathways of the hippocampalsystem and from recent functional imaging studies .Inputs Subsequently, the “what”and “where” streams of processing remain largely segregated as the perirhinalcortex projects primarily to the lateral entorhinal area, whereas theparahippocampal cortex projects mainly to the medial entorhinal area. Whilethere are also some connections between the perirhinal and parahippocampalcortices and between the entorhinal areas, the “what” and “where” informationmainly converge within the hippocampus. Hippocampal efferents back to the cortexinvolve feedback connections from the hippocampus successively back to theparahippocampal region and thence to neocortical areas from which the inputsoriginated. This anatomical evidence suggests that, during encoding, “what”information carried in the perirhinal-lateral entorhinal stream is combinedwith “where” information carried in the parahippocampal-medial entorhinalstream and the hippocampus associates items and their spatial context. When anitem is subsequently presented as a memory cue, the hippocampus completes thefull pattern and mediates a recovery of the contextual representation in theparahippocampal cortex and medial entorhinal area, and the recovery of contextconstitutes the experience of episodic recollection.In support of this model, evidence from functional imaging studies in humans indicates that theparahippocampal cortex component of the “where” stream represents spatialcontext. One line of evidence comes from the work of Kanwisher and colleagues,showing that the parahippocampal region is activated when people view spatialscenes and not objects or faces . The othWe lack studies that compare response properties of the parahippocampal cortex and the medialentorhinal area. However, the combined data from functional imaging of theparahippocampal cortex in humans and animals and our recent study of spatialfiring properties of medial entorhinal neurons suggest that both theparahippocampal cortex and medial entorhinal area components of the “where”pathway may be specialized for the processing of spatial and temporal contextin humans and animals. Much work remains to be done to test this hypothesis.However, we believe there is sufficient evidence to consider the medialentorhinal area as part of a contextual representation system rather than theembodiment of a cognitive map that guides spatial navigation.


Recent research suggests that ethnic subgroup designation plays an important role in health-related disparities among Hispanics. Our objective was to examine the influence of Hispanics' self-reported ethnic subgroup designation on perceptions of their health care providers' communication behaviors.Cross-sectional analysis of the 2005 Medical Expenditure Panel Survey (MEPS). Participants included non-institutionalized Hispanics , aged ≥18 years, reporting visiting a health care provider within the past 12 months. Six (n = 6) items were used to capture respondents' perceptions of their health care providers' communication behaviors.After controlling for socio-demographic covariates, compared to Other Hispanics (reference group), very few differences in perceptions of health care providers communication emerged across ethnic subgroups. Puerto Ricans were more likely to report that their health care provider "always" showed respect for what they had to say . Both Puerto Ricans  and Mexicans  were more likely to indicate that their health care provider "always" spent enough time with them as compared to Other Hispanics.We observed very few differences among Hispanics respondents in their perceived quality of interactions with health care providers as a function of their ethnic subgroup designation. While our findings somewhat contradict previous research, they do suggest that other underlying factors may influence the quality of perceived interactions with health care providers. Hispanic Americans now represent 15% of the total US population . For insAs health-related disparities are further examined, several researchers have raised concerns that not all Hispanics experience the same health problems. Mainous et al.  found siBecause Hispanics are a heterogeneous group, it is important to identify underlying factors that may indirectly be contributing to compromised access and worse disease. The quality of communication dynamics during the clinical encounter between the patient and health care provider could be one such factor contributing to observed health-related differences in Hispanic subgroups. For instance, perceived quality of patient-health care provider communication has shown to differ significantly between Hispanics and non-Hispanic whites. In a recent study of adults from three states, Hispanics were more likely to report that health care providers did not carefully listen to them as compared to non-Hispanics; however, respondent ethnicity was not related to differences in other communication variables . FurtherThe quality of patient-healthcare provider communication within the Hispanic population exclusively has just begun to be explored. Recently, the influence of language preference--English versus Spanish--on Hispanics' perceptions of their healthcare providers' communication behaviors was examined . OverwheHowever, to our knowledge, no studies have examined perceptions of health care communication among members of Hispanic subgroups. To address this gap in the literature, this study examined the influence of Hispanics' self-reported ethnic subgroup designation--Central/South American, Dominican, Cuban, Puerto Rican, Mexican, Other--on perceptions of their health care providers' communication behaviors during clinical encounters.We conducted an analysis of the 2005 Medical Expenditures Panel Survey Household Component file (MEPS-HC) . The MEPThe predictor variable was respondents' self-reported ethnic subgroup designation . Health services utilization models -16 were How often did providers listen carefully to you?"; (2) "How often did providers explain things so you understood?"; (3) "How often did providers show respect for what you had to say?"; and (4) "How often did providers spend enough time with you?" Additionally, those reporting having an identified USC (n = 2832) responded to the following two items: (5) "If there were a choice between treatments, how often would your provider at your USC ask you to help make the decision?" and (6) "How often does your provider at your USC show respect for treatments?" These exact [Six (n = 6) MEPS items were identified and subsequently used as outcome variables to determine respondents' perceptions of healthcare providers' communication behaviors during clinical encounters. Responses to these six items were reported on a 4-point Likert-type scale . All respondents reporting a doctor's office or clinic visit within the 12 months preceding data collection n = 5197) answered the following items: (1) "se exact ,11 and s7 answerese exact  items haa priori for all tests of statistical significance.Because the MEPS is based on a complex sampling design that makes it representative of the civilian, non-institutionalized US population, SUDAAN  statistical software (Release 9.0.3) was used to account for the weighting and complex sampling design. Alpha was set at .05 Multiple logistic regression analyses were performed to assess the association of respondents' self-reported ethnic subgroup designation on perceptions of their recent healthcare interactions, while simultaneously controlling for the effect of all covariates . For the purposes of multivariate logistic regression analyses, responses to these six MEPS items were dichotomized as "always" and "not always" . Results of the multiple logistic regression models are reported in adjusted odds ratios (ORs) with corresponding 95% confidence intervals (CIs). For the purposes of our analyses, Other Hispanics served as the reference group. This strategy--using one Hispanic subgroup as the reference group--has been used by other researchers conducting similar studies -8.In 2005, 5197 Hispanic MEPS-HC respondents , ≥18 years of age, reported visiting a healthcare provider within the 12 months preceding data collection. Socio-demographic and related characteristics of Hispanic respondents--by ethnic subgroup designation--are presented in Table As displayed in Figure After controlling for the effects of all socio-demographic and related characteristics outlined in Table This is the first study, to our knowledge, where influence of Hispanics' self-reported ethnic subgroup designation--Central/South American, Dominican, Cuban, Puerto Rican, Mexican, Other--on perceptions of their health care providers' communication behaviors during clinical encounters was examined. While significant health-related differences across Hispanic subgroups have been reported previously -8, the eShort Acculturation Scale for Hispanics which includes measures of not only language use, but also items pertaining to media use and ethnic social relations [Importantly, established health services utilization models -16 were elations .Reported measures of "respect" (for Puerto Ricans) and adequate time spent in the medical encounter were highest (for Mexicans and Puerto Ricans) among groups which tended to have the most confident use of English in the survey. Also, it must be noted that the Puerto Rican subgroup were most likely to have private health insurance. Thus, there may be other factors related to acculturation that differs among subgroups, but could not be completely captured in our language covariate. Further, although we controlled for whether or not respondents had a USC, the significant finding among Central/South Americans who felt less involved in health care decision-making may be related to an unmeasured factor that also made them least likely to report receiving care from a consistent, usual source.While we noted very few significant differences among Hispanic ethnic subgroups, a large proportion of respondents (≈30-70%) overall reported that health care providers did not "always" listen to them carefully, explain things so that they understood, show respect for what they had to say, spend enough time with them, ask them to help make health care decisions, and/or show respect for treatments. Unfortunately, these findings are troubling given the importance of and the movement toward patient-centered care ,21. NotaBased on our findings, the Hispanic population appears be a more cohesive group than has been assumed, at least in terms of their reported perceptions about health care communication. In contrast to previous studies that have found major differences among Hispanic subgroups related to accessing health care services -8, this This study has several limitations. First, although the MEPS is representative of the civilian, non-institutionalized US population, the cross-sectional format limits causality. Second, as with all observational studies that rely on self-reports, response bias remains a possibility. Third, because of the nature of secondary analyses we could not revise MEPS-HC items that pertained to the objectives of our particular study.In conclusion, we found few differences in perceptions of patient-provider communication among different Hispanic subgroups. While further study is needed, our findings suggest that responses from one large combined Hispanic ethnic group will usually represent the subgroups reliably--as long as several confounding variables are considered simultaneously --when considering their perceptions about health care communication.Ensuring equity of health, and access to high quality health information and health care, are issues common to most industrialized nations. Our study highlights the need to undertake both quantitative and qualitative exploration of health care provider communication amongst Hispanic subgroups; ensuring the issues relating to health care advice and health care access to be identified and addressed for as many people as possible.The authors declare that they have no competing interests.LW conceived of the study and drafted the manuscript. JD participated in the design of the study and helped in drafting the manuscript. ER participated in the design of the study and helped in drafting the manuscript. JP gave the research careful advice and revised the manuscript. GR gave the research careful advice and revised the manuscript. GF participated in the design of the study and conducted all statistical analyses. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6963/9/240/prepub


Biologists are gaining an increased understanding of the genetic bases of phenotypic change during evolution. Nevertheless, the origins of phenotypes mediated by novel protein-protein interactions remain largely undocumented.Here we analyze the evolution of opsin visual pigment proteins from the genomes of early branching animals, including a new class of opsins from Cnidaria. We combine these data with existing knowledge of the molecular basis of opsin function in a rigorous phylogenetic framework. We identify adaptive amino acid substitutions in duplicated opsin genes that correlate with a diversification of physiological pathways mediated by different protein-protein interactions.This study documents how gene duplication events early in the history of animals followed by adaptive structural mutations increased organismal complexity by adding novel protein-protein interactions that underlie different physiological pathways. These pathways are central to vision and other photo-reactive phenotypes in most extant animals. Similar evolutionary processes may have been at work in generating other metazoan sensory systems and other physiological processes mediated by signal transduction. Documenting the specific genetic changes driving phenotypic evolution is a fundamental goal of current biology. Genetic changes are known to modify phenotype during evolution by altering the interactions between a protein and its ecological or biochemical environment Animal phototransduction pathways offer great opportunity for elucidating the genetic basis for evolutionary novelty for a number of reasons. First, a diversity of presumably ancient phototransduction pathways exists in animals o–coupled i/t α subunit of the G-protein q α subunit in signaling o α has been identified in the Go-coupled opsin signaling pathway Retinal G-protein-coupled Receptor (RGR) and retinochromes, probably do not signal through any G-protein. Instead they are involved in the re-activation of the light reactive chromophore.Fundamental to animal phototransduction pathways are the opsin visual pigment proteins, which bind to light reactive chromophores. As members of the G protein-coupled-receptor (GPCR) family Here, we couple specific functional knowledge about opsin's role in signal transduction with new phylogenetic analyses. These analyses elucidate specific genetic changes that were likely involved in the origins of the different animal phototransduction networks, which mediate various light responses of animals. Our phylogenetically based analyses indicate a significant correlation between opsins' G-protein binding phenotypes and amino acid positions in the fourth cytoplasmic loop of opsin, especially positions homologous to 310 and 312 of bovine rhodopsin. Previous biochemical analyses demonstrate that these same amino acid positions are involved in G-protein binding function. Our additional analyses indicate that G-protein binding phenotypes likely diversified at the time of opsin gene duplication events before the origin of bilaterians, and the specific amino acid changes involved retain a pattern consistent with purifying selection.Hydra magnipapillata and Nematostella vectensis produced multiple unique opsins which all lack introns. Six of these cnidarian opsins were found in public Expressed Sequence Tag (EST) databases . We were also unable to obtain opsin sequences from the trace genome data of the placozoan Trichoplax or the choanoflagellate Monosiga. Animal (type II) opsins are also unknown from numerous fungal genomes While multiple opsins were found in the cnidarian genomes, our screens for opsins in trace data from the poriferan a prioriIn our discussion of unrooted phylogenies, we refrain from using the common terms “sister group” and “clade” in favor of the terms “adjacent group” and “clan” as the former terms imply a rooting hypothesis o–coupled opsins in an adjacent group and the second consists of the newly identified cnidops family plus the ciliary opsins, which we here confirm by phylogenetic analysis to include a non-bilaterian representative  provide new information on the timing of origin of the various opsin clades . RTA indo and rhabdomeric opsins. Our results concur with previous minima for the origins of RGR/Go and rhabdomeric opsins at the protostome-deuterostome common ancestor (Urbilateria) Nematostella gene, we did not find any Hydra genes from this ciliary opsin clade.Of the two ancient metazoan opsin lineages, one is represented in extant taxa by the newly described cnidops opsins of cnidaria, RGR/Go nodes. For the most part, the remainder of the residues in the fourth cytoplasmic loop can be unequivocally reconstructed to the level of Dayhoff classes  Our phylogeny provides a framework for understanding key transitions in the evolution of animal phototransduction pathways. Opsins interact with their corresponding G proteins, in part through binding at conserved sequence motifs located in opsin's fourth cytoplasmic loop o opsins or the ancestor of ciliary+rhabdomeric+Go clades, our reconstructed ancestral G protein interaction states for ciliary, rhabdomeric and Go are highly significant (P>0.95 for each) and are congruent with previous empirical biochemical studies We also explored the character history of G protein binding interactions by reconstructing their ancestral states across our phylogeny . While wo-coupled cascades appear to be bilaterian innovations. Third, the origins of novel phototransduction cascades, as defined by the evolution of alternative opsin-G protein interactions, co-occur on our phylogeny with the gene duplications that have given rise to the major opsin classes. Fourth, the specific mutational events that have lead to the functional diversification of the major opsin lineages are suggested by co-variation analyses and tests for selection. These results demonstrate how gene duplications, together with structural mutations that lead to novel protein-protein interactions, can contribute to the evolution of novel physiological traits. Each of these points is discussed further below.Our findings provide several new insights into the evolution of animal phototransduction cascades. First, we identify a new class of opsins that appears to be unique to cnidarians. Second, we find no evidence of any opsins in genomes of a demosponge, a parazoan, a choanoflagellate or fungi. We conclude that opsin-mediated phototransduction cascades originated early in eumetazoan evolution, after this lineage diverged from the demosponge lineage. The rhabdomeric and Go-coupled and rhabdomeric opsins are bilaterian synapomorphies also remains intact, but requires an additional loss of cnidops prior to Bilateria. The latter is also true of the topology shown in The inter-relationships of animal opsins reported here are based on thorough phylogenetic analyses that included standard phylogenetic tree estimation, comprehensive likelihood comparisons, RTA, and parametric bootstrapping . Taken tAmphimedon queenslandica, or from any non-animal genomes. While the larvae of Amphimedon are capable of phototaxis, studies of spectral sensitivity have suggested the activities of a flavin-based photoreceptor in this behavior Trichoplax or the choanoflagelate Monosiga genomes and no true homolog of type II opsins have been described outside of Metazoa Monosiga, and fungi seem to lack opsins, yet possess rhodopsin-class GPCR proteins without the Lysine residue to bind a light reactive chromophore, one possibility is that a rhodopsin-class GPCR gained the ability to bind a chromophore by substitution to a Lysine residue during animal evolution.A maximum date for the origin of animal opsins (when a GPCR first bound a light reactive chromophore) is equivocal because we did not obtain any opsins in the genome sequence of an earlier branching animal, the demosponge o-coupled opsins as sister groups Our results contrast with previous studies on opsin relationships that placed ciliary and GNematostella that in our analyses groups within the ciliary clade has been foreshadowed by previous morphological descriptions of ciliary photoreceptors Hydra probably indicates that ciliary clade opsins were lost during this species' evolutionary history.The presence of an opsin from the cnidarian Multiple lines of evidence support the hypothesis that amino acid substitutions in the 4th cytoplasmic loop of duplicated opsins were involved in the origins of novel opsin-G protein interactions. First, specific amino acid states significantly co-vary with G-protein activation phenotypes during opsin phylogeny . BecauseThese amino acid changes retain the signature of selection, as given by site-specific shifts in evolutionary rates, a statistical test that uncovers significant conservation within gene clades compared to diversification between gene clades o-coupled opsin clades , the evolution of novel phototransduction cascades in animals probably proceeded by evolving specialized protein-protein interactions between new opsin paralogs and existing G protein signaling intermediaries, an evolutionary process previously described as molecular exploitation While our inclusion of new data from the Cnidaria has greatly enhanced our ability to reconstruct opsin phylogeny, functional or phenotypic data from the newly reported cnidops clade do not exist. Further studies on the biochemistry of signaling by cnidops are required if we are to better understand the history of opsin-G protein interactions in this important family of opsins. Despite this missing data, P-values for our ancestral state reconstructions for the remaining opsin classes suggest that our results are robust.o-coupled opsins are known to exist in close proximity o-clade opsins. Such early functional requirements could have included the need to delineate light information used for vision from that used to entrain the circadian clock cycle Our finding of an adaptive, early partitioning of opsin-mediated signaling into discrete functional classes in the course of their evolution provides insight into the organismal properties of the ancestor of cnidarian and bilaterian animals. The activities of ciliary, rhabdomeric and GThe proposed relationship between gene duplication and biological complexity has been invoked and re-invoked at various points throughout the past century of biological investigation Hydra magnipapillata, Nematostella vectensis and Amphimedon queenslandica (http://www.ncbi.nlm.nih.gov/Traces) were subjected to tblastn http://www.ncbi.nlm.nih.gov/), for Hydra, or the Joint Genome Institute, for Nematostella (http://www.jgi.doe.gov/). Homologous proteins and outgroup data from bilaterian animals used in phylogenetic analyses were also obtained from NCBI (Publicly available trace genome sequence data from rom NCBI .Hydra magnipapillata (UC Irvine strain) were reared in the laboratory under standard conditions at 18°C. The expression of one opsin, HM2, was investigated in Hydra magnipapillata using in situ hybridization following Grens et al. For phylogenetic analyses, only the 7-transmembrane region including intervening inter- and extra-cellular domains was included (330 amino acids), as it was difficult to ascertain homology of N- and C- termini due to sequence length variation and lack of conservation across genes. Taxon/gene selection was done in a manner that enhanced both the taxonomic representation across the Metazoa and the inclusion of well-studied subfamilies , but also allowed for thorough computational analyses. Protein sequences were aligned using T-COFFEE under default parameters The evolutionary relationships between members of the larger GPCR class of proteins remain poorly understood. Because of this, our outgroup selection in rooted analyses was empirical. We selected the shortest-branched sequences from a pool of rhodopsin class GPCRs o and rhabdomeric). This assumption is supported by the results of unrooted MP, ML and BMCMC analyses  artifacts The number of gene duplication and loss events that are implied by a given rooting hypothesis can be used to assess the chances that a given hypothesis is tenable We scored G-protein interaction phenotypes for the opsins in our phylogenetic analysis as a discrete state character. Although these phenotypes are unknown for many opsins, especially those from non-model organisms, our analysis includes interaction data for 48% of the opsin sequences represented on our phylogeny , S1.a priori reason to assume different prior parameters, we chose this model, as it is the least parameterized model for morphological evolution possible in SIMMAP o+Rhabdomeric was significantly larger than 0: θ1 = 5.82±0.05. Site-specific posterior probabilities for residues 310 and 312 were 0.45 and 0.37 respectively.Ancestral state reconstructions and tests for correlated character evolution were conducted using Bayesian mutational mapping Table S1Sequences used in opsin phylogenetic analyses(0.11 MB DOC)Click here for additional data file.Figure S1Phylogenetic analyses of opsins without an outgroup A. ML analyses were conducted assuming the WAG +I+G+F model. B. Unweighted MP. Node numbers represent bootstrap proportions out of 1000 replicates.(3.31 MB TIF)Click here for additional data file.Figure S2Results of analyses when including non-opsin outgroup. A. BMCMC, B. MP, and C. ML. BMCMC and ML analyses were conducted under the WAG+I+G+F model. Similar analyses with other outgroups produced qualitatively similar results (not shown)(6.19 MB DOC)Click here for additional data file.


With improved angiographic techniques and magnetic resonance angiography available today, an increasing number of incidental aneurysms are being detected. Occurrence of an intracranial aneurysm together with a pituitary adenoma presents tremendous risk to the patient, particularly when the aneurysm lies near the operative field.A 61-year-old woman presented with a progressive visual field defect. Neurological examination revealed bi-temporal haemianopia. Cerebral magnetic resonance imaging and angiography revealed a pituitary macroadenoma co-existent with a cerebral aneurysm near the sellar region. The patient underwent an endovascular procedure for aneurysm embolisation and then underwent surgery for removal of the pituitary adenoma via a trans-sphenoidal approach.We report our experience and emphasize the need for critical evaluation of neuroradiological examinations for precise diagnosis for avoiding a possible life-threatening situation. The possible co-existence of an intracranial aneurysm and a pituitary adenoma has been previously reported in the literature ,2,3. WitA 61-year-old Asian Taiwanese woman presented to our institution with a progressive visual field defect. She had a history of hypertension for 20 years. Neurological examination revealed bi-temporal haemianopia. She also complained of occasional headache associated with nausea, vomiting and vertigo. Hormonal studies showed a slight elevation in prolactin levels. A brain computed tomography (CT) scan showed a slightly hyperdense lesion in the sellar region and a partially eroded sellar floor. Cerebral magnetic resonance imaging (MRI) revealed an expanding lesion inside the sella with suprasellar extension . On MRI,In this report, a 61-year-old woman was diagnosed of a pituitary macroadenoma co-existent with a cerebral aneurysm near the sellar region.Hypotheses for this phenomenon have been proposed, which include a direct mechanical effect of the pituitary adenoma on the vasculature , circulaThe incidence of intracranial aneurysms in the general population is now considered to be around 5% ,10-12. TAccording to the previous review by Locatelli et al. , an intrDifferent clinical situations affecting the sellar region present with similar neuroradiological features. Pituitary tumour apoplexy, generally caused by acute expansion of an infracted or haemorrhagic pituitary adenoma extending laterally in the cavernous sinus or toward the optic chiasma and optic nerves, is a clinical situation characterized by a sudden onset of severe headaches associated with nausea, vertigo and/or altered mental status. Ophthalmoplegia and deterioration of visual acuity and visual fields are also frequently present. In cases of subarachnoid haemorrhage caused by the rupture of cerebral aneurysm, it may be sometimes difficult to differentiate it from pituitary apoplexy, particularly when the cerebral aneurysm lies near the sellar region. One case report described the thrombosis of a cerebral aneurysm of the intra-cavernous tract of the carotid artery mimicking apoplexy of a pituitary adenoma ; anotherCerebral aneurysms can be treated by endovascular or microsurgical techniques -18. In tOur experience reinforces the need for the critical evaluation of neuroradiological examinations. In such situations, the need for precise diagnosis is emphasized to avoid a possible life-threatening situation whenever an interventional approach is considered.


P4P strategies that align reimbursement allocation with “free market” type shifts in cognitive and procedural care using evidence-based data and positive reinforcement are more likely to produce large-scale improvements in quality and cost efficiency with respect to clinical urologic care. This paper reviews current paradigms and, using BPH procedural therapy outcomes, cost, and reimbursement data, makes the case for a fundamental change in perspective to value-based pay for performance as a reimbursement system with the potential to align the interests of patients, physicians, and payers and to improve global clinical outcomes while preserving free choice of clinically efficacious treatments.The concept of “pay for performance” (P4P) applied to the practice of medicine has become a major foundation in current public and private payer reimbursement strategies for both institutional and individual physician providers. “Pay for performance” programs represent a substantial shift from traditional service-based reimbursement to a system of performance-based provider payment using financial incentives to drive improvements in the quality of care. P4P strategies currently embody rudimentary  The concept of “pay for performance” applied to the practice of medicinehas become a major foundation in current public and private payer reimbursementstrategies for both institutional and individual physician providers. Thenumber of pay for performance initiatives is growing nationwide . The goaThecurrent fee for service system is designed to reimburse healthcare providersbased principally on the volume of services provided, without consideration forthe quality of clinical outcomes. Clearly, though, the face of health careresource allocation is changing and payers are beginning to scrutinize the costsand benefits of various treatment options. Further, outcomes research andperformance-based reimbursement initiatives are underway which will change thebasis by which the performance of physicians, ancillary health professionals,and health care institutions are assessed by payers . Althougstructure and process (as opposed to outcomes)metrics which set relatively low-performance thresholds [Unfortunately,the majority of currently established quality measures are designed primarilyfor primary care physicians and institutional providers such as hospitals.Initial performance measures that could be applied to urological patients have beenreleased by CMS as part of its physician voluntary reportingprogress (PVRP) program . Exampleresholds . Furtherresholds . Exampleresholds .The net result is that initialtrials at P4P set a “low bar” for quality and cost efficiency and,therefore, are likely to produce only nominal improvements in clinical outcomesmeasures with limited global impact . MoreovThemanagement of benign prostatic hyperplasia (BPH) can serve as an excellentexample of how effective P4P paradigms might be structured and implemented inurologic practice to generate meaningful improvements in clinical outcomes. BPHis one of the most common medical conditions in the aging male population inthe US. As pharTransurethral resection of prostate(TURP) is generally the gold standard treatment for BPH against which theclinical efficacy of emerging technologies is measured. In 2003, Hoffman et al. published asystematic review of randomized controlled trials to determine the clinical efficacyof TURP . The pooComplications of TURP are well documentedin the literature. Rassweiler et al. recently updated the rates ofcomplications for TURP, including information on management and prevention basedon technological evolution . In thatEvidence-based studies that analyzetotal cost of care for procedural BPH therapies are also available. Onesophisticated peer reviewed economic analysis estimated the total payer costover a 2 year period from the time of treatment, including the cost of initialtreatment, follow-up care, adverse events, and procedural retreatment. According to this study, the 24-month totalprocedural cost of TURP was $4927 [Laser vaporization of the prostate (PVPand HoLAP) hasgained popularity due to the ability of this procedure to ablate large volumesof prostate tissue with decreased risk of complications. Additional advantagesinclude reduced need for hospitalization, shorter catheterization times, andexcellent clinical efficacy compared to standard procedural therapies andemerging minimally invasive treatments. Rajbabu et al. studied the efficiencyof photoselective vaporization of the prostate (PVP) with the potassium titanylphosphate (KTP) laser in men with prostates of >100 grams .Other researchers have performed formalmeta-analysis of KTP laser vaporization demonstrating improvements in symptomscore, maximal flow rate, and QoL scores of 76%, 221%, and 83% at 24 months,respectively [These investigators estimated the24-month total procedural cost, including expenditures for initial treatment,follow-up care, adverse events, and procedural retreatment to be $3589 . The200Interstitial laser coagulation (ILC)of the prostate can be performed in the hospital inpatient, hospital outpatient,ambulatory surgery center, or office settings under local, regional, or generalanesthesia. In 1998, Williams reported theintroduction of a volume-based treatment formula with 12-month follow-up . UnfortuIn comparison, another peer-reviewedreport using formal meta-analysis techniques demonstrated relatively highadverse event rates and a weighted average probability of retreatment of 10%along with a 24-month total procedural cost  of $4754[Transurethral Radiofrequency needleablation (TUNA) of prostate is generally performed in theoutpatient setting under local or regional anesthesia. Bouza et al. performed asystematic review and meta-analysis of TUNA in symptomatic BPH . AlthougIn a review and meta-analysis ofminimally invasive BPH procedural therapies, TUNA demonstrated improvementsfrom baseline AUA symptom score, maximum uroflowmetry rate, and quality of lifescores of 52%, 35%,and 68%, respectively, at 6 months after treatment . These rThe 24-month total procedural cost includingexpenditures for initial treatment, follow-up care, adverse events, andprocedural retreatment has been estimated at $6179 [Transurethral microwave therapy (TUMT)of the prostate also affords the advantage of being performed in the officesetting using minor sedation and local anesthesia. In evaluating clinicalmeasures of efficacy, Hoffman et al. performed a review of randomizedcontrolled trials to evaluate urinary symptom improvement, urinary function,prostate volume, mortality, morbidity, and retreatment rates . In thatAn analysis of reported outcomesdata from the comprehensive AUA BPH guidelines demonstrated 39%–46% symptom score improvement at 24 months .MaximalIn that study, the expected costper patient at 24 months, including expenditures for initial treatment,follow-up care, adverse events, and procedural retreatment was $5461 when usingProstatron 2.0, $5488 with Prostatron 2.5 and $5699 with the Targis system .A review of 2008 Medicare feeschedule physician reimbursement for TUMT indicates an approximate value of $2901.75in the office site of service and $536.34 for a hospital-based procedure (Laser enucleation of the prostate (HoLEP) is generallyperformed in the hospital outpatient or inpatient setting and provides arelatively minimally invasive means of removing a broad range of obstructingprostate adenomas. Studies of clinical efficacy have documented profoundimprovements in outcomes metrics including symptom score, quality of life score,and uroflowmetry rates that compare favorably to the gold standard TURP procedure, 17. In Armed with a thorough understandingof clinical outcomes, cost, and reimbursement data for commonly performed BPHprocedural options, it is now possible to examine opportunities for developingP4P programs in urology using this disease entity as an example. To be sure, few would dispute the conceptual valueof transforming the current system of medical service reimbursement with a morerationale, evidence-based approach. The challenge in proposing a P4P scheme forBPH procedural therapy is to understand the method by which physicianreimbursement for professional services is calculated and the role of thissystem in influencing clinical outcomes. Then, a proposal can be developedwhich outlines potential ways that physician payment allocation might be restructuredto drive aggregate physician decision making toward the selection of proceduralservices that result in improved outcomes while also preserving free choice froma market basket of therapeutic alternatives with heterogeneous clinical andeconomic performance characteristics.The first step in proposing aneffective pay for performance initiative for BPH procedural therapy is tointernalize the complexity of the calculation used to formulate Medicarereimbursement for specific treatment options. At its core, the resource-based relative value scale system forphysician payments (RBRVS) was developed from the principle that the “relativevalue” of physician services is comprised of 3 essential components: (1) thephysician work expendedperforming a medical service, (2) the practice expense attributable toproviding that service, and (3) the component of malpractice expense that canbe allocated to the distinct procedural or cognitive care . Total MA review of the previous analysisof outcomes, cost, and physician payment data for BPH procedural treatment inthe context of the RBRVS methodology provides an unambiguous view of the waythat reimbursement strategies can affect clinical outcomes. From this review, two major points are evident. First, physician reimbursement for BPHprocedural therapy demonstrates marked variation based primarily on differencesin key inputs to the RBRVS calculation which are impacted by the technologiesemployed and the site of service utilized in performing these procedures. Second, even allowing for adjustments basedon procedural overhead cost, there is clear misalignment between evidence-basedclinical outcomes measures and current Medicare fee schedule physicianreimbursement for commonly performed BPH procedures.This misalignment creates an environmentin which choices between objective outcomes measures and physicianreimbursement are in competition during the process of BPH procedural treatmentselection. In this way, the current reimbursement paradigm for BPH proceduraltherapy actually works to select for less optimal clinical outcomes asphysicians are forced into an awkward position, where rational decisions cannotbe made on the basis of clinical outcomes and reimbursement at the same time. Tobe sure, other factors should also play a substantial role in determining theappropriate BPH procedural treatment for a given patient. Proper treatmentselection should reflect sound joint decision making and consumer-centered carethat reflects both the physician's use of evidence-based information and theincorporation of patient specific factors including the relative importance ofadverse event rates, comorbidities, location of service, objective clinicalimprovement, and cost. However, by placingreimbursement and outcomes in direct opposition, the current volume-basedmethodology for allocating physician reimbursement for BPH therapies creates asizeable barrier to the development of a workable pay for performance program.aggregate physician-patient joint decisionmaking.Addressing the challenge ofproposing a viable P4P paradigm for BPH procedural treatment or any othermedical service requires several important steps. First, policymakers must fix the RBRVS/SGRmethodology to resolve recurring problems with the econometric formulaincluding, but not limited to, inaccuracies in the estimation of the practiceexpense component for procedural reimbursement and the flawed link betweenphysician payment calculations and variation in the GDP . Second,value-based (as opposed to volume-based)decision making are more likely to result in sustainable quality improvement [The potential benefits tostructuring an effective pay for performance paradigm for BPH proceduraltherapy are enumerable. Effective treatment selection can have an enormousimpact on downstream outcomes indicators including the degree of clinicalimprovement and the risk of adverse events which, in turn, largely determinethe real cost of care . Furtherrovement . Properlstructure and process metrics are unlikely to producelasting quality or cost improvements as these methodologies do little topromote competition based on the overall value of medical services provided [Conversely, punitive P4P programsthat use rudimentary provided .Moreoveprovided . The netHypothetically, physicianreimbursement for BPH procedures can be structured in at least 3 basic ways. Atone extreme, physician payments can be allocated without incorporating clinicaloutcomes measures in the calculation. This case example results in the currentsystem, where the choice from among competing alternatives is based on a numberof interrelated factors. In this scenario, while procedures with superiorefficacy will sometimes be chosen, clinical outcomes in the aggregate willnever be optimized as competing incentives allow less efficacious treatments tobe selected disproportionately. At the other extreme, physician payments can beallocated equally among the various treatment alternatives. This case wouldresult in an environment, where there is no direct economic incentive to chooseany one BPH treatment. In this scenario, treatment decision making may resultin the selection of procedures with healthier outcomes characteristics but thelack of economic incentives would continue to result in a subset of providersutilizing less efficacious alternatives for other reasons including differencesin the learning curve to master particular techniques and the capacity of sometechnologies to be more amenable to volume-based practice.value-based P4P isthe only practicable way to appropriately structure BPH procedural treatmentselection to improve clinical outcomes by aligning the interests of physicians,patients, and payers with rational reimbursement policy. In this case,physician payments would be weighted and allocated based on a validatedanalysis of evidence-based outcomes data. BPH procedures that exhibit betteroutcomes performance characteristics would be allocated greater physicianreimbursement and competition between reimbursement and outcomes would be curbed.Moreover, value-based P4P thatutilizes clinical outcomes as the core performance measure, as opposed topunitive structure and process metrics, would move away from individualphysician performance assessment with its inherent limitations to a system thatmaintains free choice from among the available treatment alternatives while atthe same time providing market-based positive reinforcement to globally influenceaggregate physician decision making toward procedures with superioroutcomes characteristics . In this way, the frame of reference and focus appropriatelyshifts from theindividual provider to the therapies provided and allows physicians and patients to make rational,evidence-based treatment decisions.In the end, value-based P4P for BPH procedural treatment or any other medical condition is the availabilityof clinically meaningful outcomes criteria which can be populated with uniformevidence-based data [value-basedP4P can integrate more sophisticated metrics including “total cost of care” which by incorporating factors such as thecosts of initial therapy, follow-up care, management of adverse events, andretreatment can act as a valuable measure of clinical efficacy [Certainly, the rate limiting stepin the development of sed data . Howeversed data . Furtherefficacy .value-basedpay for performance as a reimbursement system with the potential toalign the interests of these distinct constituencies and to improve globalclinical outcomes while preserving free choice of clinically efficacioustreatments.In conclusion, doctors and other providers should be rightlycautious about current P4P initiatives that use rudimentary metrics andpunitive reimbursement policy and which fail to differentiate participants or improveaggregate clinical outcomes. However,urologists, patients, and payers should embrace the concept of


Cases of true mycotic popliteal artery aneurysm are rare. Presentation is variable but invasive and non-invasive investigations collectively facilitate diagnosis and guide operative procedures. Definitive treatment generally utilizes surgical intervention with excision and reconstruction using autologous vein graft. Prolonged targeted antibiotic therapy is an important adjuvant.Streptococus pneumoniae endocarditis.We describe the clinical presentation, radiological investigations and strategies on the management of a 47-year-old Caucasian Irish man who presented with a mycotic aneurysm of the popliteal artery due to thromboembolisation from Streptococus pneumoniae highlighting the changing profile of causative microorganisms.Cases of true mycotic popliteal artery aneurysms are rare. To the best of our knowledge this is the first documented case of a popliteal artery mycotic aneurysm developing secondary to  Streptococus pneumoniae endocarditis.True mycotic popliteal artery aneurysm is a rare condition and its presentation is variable. Definitive treatment is generally characterised by excision and reconstruction using an autologous vein graft. We describe the clinical presentation, radiological investigations and management strategies employed in the case of a 47-year-old man who presented with a mycotic aneurysm of the popliteal artery (MPAA) secondary to thromboembolisation from Streptococus pneumoniae endocarditis vegetations. After a prolonged ICU course, the patient was eventually transferred to the ward with minimal neurological dysfunction. The patient, however, developed pain in his right calf 6 weeks after admission.A 47-year-old Caucasian Irish man was admitted to our intensive care unit (ICU) with multiple cerebral infarcts secondary to septic emboli from A clinical examination revealed a pyrexic patient with a swollen, pulsatile and tender right upper calf mass, palpable distal pedal pulses and foot drop Figure . A mycotThe contralateral popliteal artery was normal Figure . Urgent A curved incision over the right popliteal fossa revealed a saccular aneurysm of the below- knee popliteal artery involving the trifurcation. Proximal control was attained and the aneurysm opened, exposing a significant amount of haematoma and thrombus Figure . SamplesA femoral angiogram performed 2 weeks after the procedure demonstrated satisfactory graft segment flow Figure . No orgaAccording to Wilson's widely held classification, mycotic aneurysms are strictly defined as "infected aneurysms developing in a previously normal artery secondary to septic embolisation due to bacterial endocarditis" . Thus, aTo date there are fewer than 50 cases of "true" MPAA reported in the literature. The estimated male-to-female ratio is 11:3 with an age range of 2 to 81 years with the mean age of occurrence at 41 years old [MPAA customarily presents as a painful, tender, pulsatile leg swelling in pyrexic patients with a definitive or unsuspected infective focus . SymptomAlthough an estimated 3% of non-mycotic popliteal artery aneurysms can produce neurological symptoms and signs, possibly due to direct compression or occlusion of the vasonervorum arising from the popliteal artery , our patLaboratory studies are unhelpful in diagnosing MPAA and often indicate a non-specific leukocytosis or increased erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Blood cultures are positive in only 50% of reported cases, but negative blood cultures and Gram stains do not necessarily rule out a mycotic aneurysm Table .Non-invasive procedures such as colour-duplex ultrasonography, CT and magnetic resonance imaging (MRI) or angiogram can establish a diagnosis of postoperative alopecia areata (PAA) and provide information regarding the size, diameter, morphology (saccular morphology being suggestive of an infective aetiology) and its relationship to surrounding structures .Angiography, either conventional or digital subtraction, is important to demonstrate the status of the inflow and outflow vessels, hence guiding any operative approach ,5.CT and MRI as vessel imaging alternatives can be satisfactory, as in this case where the patient's temporary sepsis-related renal impairment precluded formal contrast angiography .Ankle brachial index (ABI) measurements provide an objective, measurable and repeatable index of ischemia. Broad-spectrum antibiotics should be commenced pre-operatively and continued for a variable period postoperatively. If no causative pathogen is identified, at least two synergistic agents should be employed. Since there are no clear guidelines regarding the duration of postsurgical therapy, a 6-week oral course seems to be a prudent approach ,10.in situ vessels or reversed superficial vein from the ipsilateral or contralateral lower (or upper) limb [MPAA generally mandates resection and revascularisation -8,10. Ther) limb ,10. Deeper) limb ).The literature includes only a few reports of amputation, failure of reconstructive procedure and the need for secondary reconstruction or amputation, which probably reflects an unwillingness to publish perceived treatment failures. It is thus reasonable to assume a total limb salvage rate, a 5-year patency rate and a primary and/or secondary amputation rate that are at least comparable with, if not worse than, those of non-mycotic popliteal aneurysms (in the region of 60-72%, 50-86%, and 18-27.5% and/or 28-40%, respectively [Mycotic popliteal artery aneurysm is a rare but potentially devastating condition. A high index of suspicion is therefore necessary. Invasive and non-invasive investigations facilitate diagnosis and guide operative procedures. Surgical intervention with excision and reconstruction using an autologous vein graft is the method of choice. Prolonged antibiotic therapy should initially be broad spectrum until pathogen identification can allow targeted therapy.ABI: ankle brachial index; CT: computer tomography; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; ICU: intensive care unit; MPAA: mycotic aneurysm of the popliteal artery; PAA: postoperative alopecia areata;Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.The authors declare that they have no competing interests.SK retrieved all clinical data and conducted the literature review. NOB and MOS supplied the radiological images and also contributed to the literature review. HPR and GK were major contributors to the overall writing of the manuscript. GF contributed to the literature review, performed the procedure described, supplied the clinical images and conducted the specimen analysis. All authors read and approved the final manuscript.


Abdominal lymphadenopathy (AL) - a common clinical scenario faced by clinicians - often poses a diagnostic challenge. In the absence of palpable peripheral nodes, tissue has to be obtained from the abdominal nodes by image-guided biopsy or surgery. In this context a laparoscopic biopsy avoids the morbidity of a laparotomy.This retrospective analysis of prospectively collected data represents our experience with laparoscopic biopsy of abdominal lymph nodes.Between October 2000 and November 2005, 28 patients with AL underwent laparoscopic biopsy. Pre-operative radiological imaging studies had identified a nodal mass in 20, a solitary node in 1, a cold abscess in 1 and a mesenteric cystic lesion in 1 patient. In five patients with chronic right lower abdominal pain and normal ultra-sonographic findings mesenteric nodes were identified and biopsied during diagnostic laparoscopy.The sites of biopsied lymph nodes included para-aortic (10), mesenteric (8), external iliac (3), left gastric (2), obturator (1), aorto-caval (1) and porta hepatis (1). One patient with enlarged peripancreatic nodes mass and another with a mesenteric cystic mass had cold abscesses drained in addition to biopsy. There were no perioperative complications and the median postoperative stay was 2 days (range 1-4 days). Histopathology revealed tuberculosis in 23 patients, reactive adenitis in 2, lymphoma in 1 metastatic carcinoma in 1, and a retroperitoneal sarcoma in 1.In patients with AL, laparoscopy provides a safe and effective means of obtaining biopsy. It is of particular value in patients in whom (a) the nodes are small or present in locations unsuitable for image-guided biopsy, (b) adequate tissue cannot be obtained by image-guided biopsy or (c) previously undiagnosed lymphadenopathy is encountered during diagnostic laparoscopy. A patient presenting with abdominal lymphadenopathy (AL) is a common scenario in clinical practice. In those who have associated peripheral lymphadenopathy (PL) a biopsy, which can often be performed under local anesthesia, often yields the diagnosis. However, in the absence of PL diagnostic tissue is more difficult to obtain.Image-guided needle biopsy (IGNB), whenever feasible, represents a minimally invasive method of obtaining tissue from enlarged abdominal lymph nodes. However, diagnosis may be difficult when needle biopsy yields inadequate tissue or tissue that has lost its architecture. In patients with nodes situated in close proximity to major blood vessels or important viscera, IGNB may be hazardous. Moreover, in patients suspected to have lymphoma, IGNB fails to provide adequate tissue specimen to allow special tests for accurate sub-classification.Surgeons experienced in laparoscopic surgery are able to biopsy lymph intra-abdominal at almost all locations including those from areas that are considered difficult to access by IGNB. Moreover, laparoscopy affords the surgeon an opportunity to examine the entire abdominal viscera. In this study we review our experience with the use of laparoscopic biopsy in patients with AL.Between October 2000 and January 2006, 28 patients underwent laparoscopic biopsy of AL. We retrospectively analyzed prospectively collected data on these patients. There were nine men and 19 women with a median age of 27 years (range 6-77 years). The presenting features included chronic abdominal pain (7), pain, weight loss and fever (10), pain and weight loss (3), abdominal lump (2), pyrexia of unknown origin (5), and backache (1). None of these patients had palpable peripheral lymph nodes suitable for biopsy. In 23 patients, pre-operative ultrasound scan and/or computerized tomography (CT) scan had identified the site of lymphadenopathy . One patAll operations were carried out under general endotracheal anesthesia with the patients placed in modified Lloyd-Davis, left lateral, right lateral or Trendelenburg positions to optimally expose the site of identified lymphadenopathy. A nasogastric tube and Foley catheter were inserted as appropriate; both were removed at the end of surgery.For upper abdominal procedures a 10-mm camera port was placed slightly above the umbilicus and a 5-mm working port in each mid-clavicular line. In addition, a self-retaining retractor was set up to retract the left lobe of liver. The para-aortic nodes were biopsied by placing the camera port to the right of the midline at the level of umbilicus and two working ports in the midline on either side. For biopsy of the external iliac lymph nodes, the camera port was placed at the umbilicus along with two 5-mm port in para-rectus positions. In patients with chronic abdominal pain undergoing diagnostic laparoscopy a 10-mm camera port was placed at the umbilicus and two 5-mm ports were placed in supra-pubic region and left iliac fossa.In all patients a preliminary exploratory laparoscopy was undertaken to examine the peritoneal surface, bowel and liver. The bowel and viscera were displaced from the site of lymphadenopathy by further tilting the table. The peritoneum overlying the lymph nodes was incised and the surface cleared to create a wide window. Either a complete node (when the nodes were discrete) or two to three incisional biopsies  were obtained . After tLaparoscopic lymph node biopsy was completed in all patients. Out of the 23 patients diagnosed to have tubercular lymphadenopathy, 22 were treated with first-line anti-tubercular drug therapy. In one patient undergoing laparoscopic biopsy of a mesenteric nodal mass responding poorly to empirical anti-tubercular therapy, the organisms were found to be susceptible to second-line anti-tubercular drugs. Two patients in whom the mesenteric lymph nodes revealed reactive changes received no further treatment. One patient who had previously undergone surgery for carcinoma of cervix and was found to have metastatic obturator nodes refused further therapy. The patient with lymphoma underwent chemotherapy. This patient at original presentation had a serum creatinine of 1.8 mg% along with left-sided hydronephrosis and hydroureter. A JJ stent inserted at the time of nodal biopsy was removed 3 months later after regression of the nodes following chemotherapy.The common clinical scenarios in which AL manifests include a palpable mass, pyrexia of unknown origin or lymphadenopathy identified on imaging studies or at laparotomy/laparoscopy. Common causes of AL are metastases, tuberculosis, lymphoma, sarcoidosis, and non-specific inflammation.In the developing world lymphadenopathy is a common manifestation of abdominal tuberculosis. Although, ultra-sonography and CT are useful in identifying AL, imaging findings may not always disease-specific. Nodes with low density centers, although characteristic of tuberculosis, are not pathognomonic and nodal calcification suggestive of tuberculosis can also be observed in metastases from testicular teratoma and non-Hodgkin's lymphoma. Thus, acet al. attempted laparoscopic biopsy in 94 patients and completed it successfully in 78.[Another common indication for laparoscopic biopsy of abdominal lymph nodes reported in the literature is establishment of diagnosis and sub-classification of lymphoma. In experienced hands, use of CT-guided core biopsy of abdominal lymph nodes located in favorable locations can provide adequate samples. However, IGNB techniques may yield inadequate tissue and on occasions, presence of nodes adjacent to major blood vessels or important viscera may render this modality hazardous. Asoglu ly in 78. A laparoly in 78.7 AbilityIn patients undergoing diagnostic laparoscopy for chronic right lower abdominal pain, previously unidentified small mesenteric nodes may be picked up. We always excise completely a representative node in such a situation. Three of five patients who underwent biopsy of incidentally detected mesenteric nodes during diagnostic laparoscopy were found to have lymph nodal tuberculosis. As all these patients had longstanding right lower abdominal pain, an appendicectomy was performed concurrently to avoid future diagnostic confusion.et al. reported 15 patients with PUO who underwent diagnostic laparoscopy.[Lymph nodes identified on imaging studies in patients being investigated for pyrexia of unknown origin (PUO) forms yet another indication for laparoscopic lymph node biopsy. Arch-Ferrer aroscopy. Tissue sSome of the technical aspects of laparoscopic biopsy of abdominal lymph nodes merit elucidation. A careful study of the CT scan helps in planning the approach to the target area and position of ports. Proper positioning of the patient allows the bowel and other viscera to fall away from the site of lymphadenopathy. A liver retractor may have to be placed when working in the upper abdomen. Large nodal masses are readily apparent through the overlying peritoneum but in obese patients discrete nodes may sometimes be hidden in fatty tissue making their identification difficult. A generous incision on the peritoneum and a careful search usually reveals the nodes even when solitary or small. Whenever feasible, we prefer to obtain at least one complete node, but in presence of a nodal mass a block of tissue no less than 1 × 1 cm is excised. During excision/biopsy of the node use of electrocautery is kept to a minimum as its excessive use damages the nodal architecture making the histopathological interpretation difficult. Swabbing with a small piece of gauze introduced in the peritoneal cavity is used for maintaining a blood-free operative field. We prefer to extract the biopsy specimen with the use of a 10-mm cup forceps or by placing it inside a plastic bag so as not to crush/damage it. Whenever available, intra-operative frozen section is obtained to confirm adequacy of the specimen.Our series does not represent all patients with AL seen at the institution during the study period. Majority were patients in whom an IGNB had failed or was not feasible thus leading to a referral for laparoscopic lymph node biopsy. It is likely that in several other patients either biopsy of palpable peripheral nodes or an IGNB had provided the diagnosis. Thus analysis of our data is unable to provide an insight into the percentage of patients with AL who may go on to require a laparoscopic biopsy.To summarize, laparoscopic biopsy represents a minimally invasive method of obtaining tissue from enlarged abdominal nodes present in locations unsuitable for IGNB, when tissue obtained by IGNB is inadequate and when previously unsuspected lymphadenopathy is identified during diagnostic laparoscopy. This method allows a surgeon experienced in laparoscopic technique to obtain adequate-sized biopsy specimen under visual control from lymph nodes in almost any intra-abdominal location. With its easy availability, early and judicious use of laparoscopic biopsy should be considered in the algorithm of work up of patients with AL.