Thromboelastometry-guided surgery in neuroblastoma complicated with disseminated intravascular coagulation. / Cirugía guiada por tromboelastometría en neuroblastoma complicado con coagulación intravascular diseminada.

BACKGROUND: Disseminated intravascular coagulation (DIC) is a rare oncological emergency. We report a pediatric neuroblastoma complicated with DIC which required thromboelastometry-guided surgery. OBSERVATION: A 6-year-old female diagnosed with intermediate risk adrenal neuroblastoma developed tumor-related DIC after chemotherapy first cycle. She remained stable without clinical bleeding and emergent tumor resection guided by intraoperative-thromboelastometry was decided. DIC resolved early after surgery and complete remission was achieved. CONCLUSION: Treatment of the underlying condition is critical to manage DIC. Thromboelastometry can guide goal-directed therapy, including surgery in pediatric patients. However, larger studies are needed to examine its applicability in different clinical settings, such as cancer related DIC.

INTRODUCCION: La coagulación intravascular diseminada (CID) es una urgencia oncológica poco común. Describimos el caso de un neuroblastoma pediátrico complicado con CID que precisó de cirugía guiada por tromboelastometría. CASO CLINICO: Paciente de seis años diagnosticada de neuroblastoma suprarrenal de riesgo intermedio que desarrolló CID asociada al tumor tras el primer ciclo de quimioterapia. Permaneció estable sin hemorragia clínica, decidiéndose una resección tumoral de urgencia guiada por tromboelastometría intraoperatoria. La CID se resolvió poco después de la cirugía, consiguiéndose una remisión total. CONCLUSION: El tratamiento de la patología subyacente es clave a la hora de manejar la CID. La tromboelastometría puede guiar la terapia orientada a objetivos, también en cirugías realizadas en pacientes pediátricos. No obstante, hacen falta mayores estudios que analicen su aplicabilidad en distintos contextos clínicos, como la CID relacionada con cáncer.

Cirugía guiada por tromboelastometría en neuroblastoma complicado con coagulación intravascular diseminada / Thromboelastometry-guided surgery in neuroblastoma complicated with disseminated intravascular coagulation

Introducción: La coagulación intravascular diseminada (CID) es una urgencia oncológica poco común. Describimos el caso de un neuroblastoma pediátrico complicado con CID que precisó de cirugía guiada por tromboelastometría. Caso clínico. Paciente de seis años diagnosticada de neuroblastoma suprarrenal de riesgo intermedio que desarrolló CID asociada al tumor tras el primer ciclo de quimioterapia. Permaneció estable sin hemorragia clínica, decidiéndose una resección tumoral de urgencia guiada por tromboelastometría intraoperatoria. La CID se resolvió poco después de la cirugía, consiguiéndose una remisión total. Conclusión. El tratamiento de la patología subyacente es clave a la hora de manejar la CID. La tromboelastometría puede guiar la terapia orientada a objetivos, también en cirugías realizadas en pacientes pediátricos. No obstante, hacen falta mayores estudios que analicen su aplicabilidad en distintos contextos clínicos, como la CID relacionada con cáncer.(AU)

Background: Disseminated intravascular coagulation (DIC) is a rare oncological emergency. We report a pediatric neuroblastoma complicated with DIC which required thromboelastometry-guided surgery. Observation. A 6-year-old female diagnosed with intermediate risk adrenal neuroblastoma developed tumor-related DIC after chemotherapy first cycle. She remained stable without clinical bleeding and emergent tumor resection guided by intraoperative-thromboelastometry was decided. DIC resolved early after surgery and complete remission was achieved. Conclusion. Treatment of the underlying condition is critical to manage DIC. Thromboelastometry can guide goal-directed therapy, including surgery in pediatric patients. However, larger studies are needed to examine its applicability in different clinical settings, such as cancer related DIC.(AU)

Fluid-structure interaction simulations outperform computational fluid dynamics in the description of thoracic aorta haemodynamics and in the differentiation of progressive dilation in Marfan syndrome patients.

Abnormal fluid dynamics at the ascending aorta may be at the origin of aortic aneurysms. This study was aimed at comparing the performance of computational fluid dynamics (CFD) and fluid-structure interaction (FSI) simulations against four-dimensional (4D) flow magnetic resonance imaging (MRI) data; and to assess the capacity of advanced fluid dynamics markers to stratify aneurysm progression risk. Eight Marfan syndrome (MFS) patients, four with stable and four with dilating aneurysms of the proximal aorta, and four healthy controls were studied. FSI and CFD simulations were performed with MRI-derived geometry, inlet velocity field and Young's modulus. Flow displacement, jet angle and maximum velocity evaluated from FSI and CFD simulations were compared to 4D flow MRI data. A dimensionless parameter, the shear stress ratio (SSR), was evaluated from FSI and CFD simulations and assessed as potential correlate of aneurysm progression. FSI simulations successfully matched MRI data regarding descending to ascending aorta flow rates (R 2 = 0.92) and pulse wave velocity (R 2 = 0.99). Compared to CFD, FSI simulations showed significantly lower percentage errors in ascending and descending aorta in flow displacement (-46% ascending, -41% descending), jet angle (-28% ascending, -50% descending) and maximum velocity (-37% ascending, -34% descending) with respect to 4D flow MRI. FSI- but not CFD-derived SSR differentiated between stable and dilating MFS patients. Fluid dynamic simulations of the thoracic aorta require fluid-solid interaction to properly reproduce complex haemodynamics. FSI- but not CFD-derived SSR could help stratifying MFS patients.

Structural and molecular study of the supraspinatus muscle of modern humans (Homo sapiens) and common chimpanzees (Pan troglodytes).

OBJECTIVES: To analyze the muscle architecture and the expression pattern of the myosin heavy chain (MyHC) isoforms in the supraspinatus of Pan troglodytes and Homo sapiens in order to identify differences related to their different types of locomotion. MATERIALS AND METHODS: We have analyzed nine supraspinatus muscles of Pan troglodytes and ten of Homo sapiens. For each sample, we have recorded the muscle fascicle length (MFL), the pennation angle, and the physiological cross-sectional area (PCSA). In the same samples, by real-time quantitative polymerase chain reaction, we have assessed the percentages of expression of the MyHC-I, MyHC-IIa, and MyHC-IIx isoforms. RESULTS: The mean MFL of the supraspinatus was longer (p = 0.001) and the PCSA was lower (p < 0.001) in Homo sapiens than in Pan troglodytes. Although the percentage of expression of MyHC-IIa was lower in Homo sapiens than in Pan troglodytes (p = 0.035), the combination of MyHC-IIa and MyHC-IIx was expressed at a similar percentage in the two species. DISCUSSION: The longer MFL in the human supraspinatus is associated with a faster contractile velocity, which reflects the primary function of the upper limbs in Homo sapiens-the precise manipulation of objects-an adaptation to bipedal locomotion. In contrast, the larger PCSA in Pan troglodytes is related to the important role of the supraspinatus in stabilizing the glenohumeral joint during the support phase of knuckle-walking. These functional differences of the supraspinatus in the two species are not reflected in differences in the expression of the MyHC isoforms.

Inter- and Intraspecific Variations in the Pectoral Muscles of Common Chimpanzees (Pan troglodytes), Bonobos (Pan paniscus), and Humans (Homo sapiens).

We have analyzed anatomic variations in the pectoralis major and pectoralis minor muscles of common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) and compared them to anatomic variations in these muscles in humans (Homo sapiens). We have macroscopically dissected these muscles in six adult Pan troglodytes, five Pan paniscus of ages ranging from fetus to adult, and five adult Homo sapiens. Although Pan troglodytes are thought to lack a separate pectoralis abdominis muscle, we have identified this muscle in three of the Pan troglodytes; none of the Pan paniscus, however, had this muscle. We have also found deep supernumerary fascicles in the pectoralis major of two Pan troglodytes and all five Pan paniscus. In all six Pan troglodytes, the pectoralis minor was inserted at the supraspinatus tendon, while, in Pan paniscus and Homo sapiens, it was inserted at the coracoid process of the scapula. Some of the anatomic features and variations of these muscles in common chimpanzees and bonobos are similar to those found in humans, therefore enhancing our knowledge of primate comparative anatomy and evolution and also shedding light on several clinical issues.

Arterial pulse attenuation prediction using the decaying rate of a pressure wave in a viscoelastic material model.

The present study examines the possibility of attenuating blood pulses by means of introducing prosthetic viscoelastic materials able to absorb energy and damp such pulses. Vascular prostheses made of polymeric materials modify the mechanical properties of blood vessels. The effect of these materials on the blood pulse propagation remains to be fully understood. Several materials for medical applications, such as medical polydimethylsiloxane or polytetrafluoroethylene, show viscoelastic behavior, modifying the original vessel stiffness and affecting the propagation of blood pulses. This study focuses on the propagation of pressure waves along a pipe with viscoelastic materials using the Maxwell and the Zener models. An expression of exponential decay has been obtained for the Maxwell material model and also for low viscous coefficient values in the Zener model. For relatively high values of the viscous term in the Zener model, the steepest part of the pulse can be damped quickly, leaving a smooth, slowly decaying wave. These mathematical models are critical to tailor those materials used in cardiovascular implants to the mechanical environment they are confronted with to repair or improve blood vessel function.

A human plasma derived supplement preserves function of human vascular cells in absence of fetal bovine serum.

Current techniques for cell culture routinely use animal-derived components. Fetal bovine serum (FBS) is the most widely applied supplement, but it often displays significant batch-to-batch variations and is generally not suitable for clinical applications in humans. A robust and xeno-free alternative to FBS is of high interest for cellular therapies, from early in vitro testing to clinical trials in human subjects. In the current work, a highly consistent human plasma derived supplement (SCC) has been tested, as a potential substitute of FBS in primary human vascular cells culture. Our results show that SCC is able to support proliferation, preserve cellular morphology and potentiate functionality analogously to FBS. We conclude that SCC is a viable substitute of FBS for culture and expansion of cells in advanced therapies using human vascular cells and fibroblasts.

Floquet-Bloch solutions in a sawtooth photonic crystal.

Band structure of a sawtooth photonic crystal for optical wave propagation along the axis of periodicity is investigated. Floquet-Bloch solutions are found and illustrated for the bandgaps, allowed bands, and bandedges of the crystal. Special attention is given to the cases where Floquet-Bloch solutions become periodic functions.

Trichophyton erinacei in pet hedgehogs in Spain: Occurrence and revision of its taxonomic status.

Hedgehogs have increased in popularity as pets in Spain but there are no data of infection rates of this exotic animal with dermatophytes in our country. During the period of 2008-2011 a total of 20 pet hedgehogs (19 African pygmy hedgehogs and 1 Egyptian long-eared hedgehog) suspected of having dermatophytoses were studied. This is the first survey of the occurrence of T. erinacei in household hedgehogs in Spain. The T. erinacei infection rate was 50% (9 out of 19 African pygmy hedgehogs, and the one Egyptian long-eared hedgehog surveyed). Morphological identification of the isolates was confirmed by molecular analysis. All the strains had the same ITS sequence and showed 100% sequence similarity to T. erinacei type strain CBS 511.73 (AB 105793). The Spanish isolates were confirmed as T. erinacei urease positive. On the basis of ITS sequences, T. erinacei is a species close to but separate from the taxa included in the A. benhamiae complex. Review of the current literature on DNA-based methods for identification of species included in this complex has highlighted the urgent need to reach a consensus in species circumscription and classification system accepted by all mycologists.

Clinical, Cytological, Histological and Immunohistochemical Features of Cutaneous Mast Cell Tumours in Ferrets (Mustela putorius furo).

Cutaneous mast cell tumours (cMCTs) are one of the most common cutaneous tumours in ferrets (Mustela putorius furo). However, limited information is available regarding cytological and histological features of these tumours and studies evaluating KIT expression are lacking in this species. The aims of this prospective study were to describe the most common clinical, cytological and histological features of cMCTs in ferrets and to compare the usefulness of different staining techniques in the diagnosis of these tumours in ferrets as well as evaluating KIT expression in neoplastic mast cells (MCs) by immunohistochemistry. Macroscopically, the tumours were small, round to plaque-like and frequently associated with surface crusting. The most common locations were the extremities and the trunk. MC granules were stained in all cases using toluidine blue (TB) and Wright-Giemsa stains in cytological specimens, but none stained with modified Wright's stain. Haematoxylin and eosin and TB on histological sections failed to stain MC granules in all the cases. Cytological and histological examination revealed low to moderate anisocytosis and anisokaryosis. An infiltrative rather than a delineated or encapsulated growth pattern was noted histologically in all cases. Eosinophilic infiltration was not uncommon and 'collagenolysis' was detected on cytological and histological examination. KIT expression was detected in all cases evaluated. In approximately one third of the cases the MCs exhibited KIT labelling pattern I and in the remaining ferrets, KIT pattern III. No correlation was found between KIT expression pattern and biological behaviour.

Recomendaciones de tromboprofilaxis en Cirugía Mayor Ambulatoria. Documento multidisciplinar de consenso de la Asociación Española de Cirugía Mayor Ambulatoria (ASECMA) / Recommendations for thromboprophylaxis in major ambulatory surgery. Multidisciplinary consensus document of the Spanish Association for Major Ambulatory Surgery (ASECMA)

La cirugía ambulatoria presenta un incremento constante, tanto en los procedimientos que se llevan a cabo como en las unidades capacitadas para su realización. Uno de los aspectos esenciales en su desarrollo es la mejoría permanente de los cuidados prequirúrgicos que reciben los pacientes. Entre ellos, ocupa un lugar destacado la profilaxis antitrombótica y, si bien la incidencia global de la enfermedad tromboembólica venosa en este grupo de pacientes no es muy elevada, se recomienda valorar en todos los pacientes los factores de riesgo trombótico personales y los relacionados con el procedimiento quirúrgico. Según esta valoración, los pacientes se podrán estratificar en bajo o moderado/alto riesgo trombótico, recomendándose aplicar las medidas de tromboprofilaxis adecuadas en cada caso: medidas generales solas o en combinación con tromboprofilaxis farmacológica y/o mecánica. En el presente documento multidisciplinar de consenso, actualización de las recomendaciones de la Asociación Española de Cirugía Mayor Ambulatoria (ASECMA) publicadas en 2011, se establecen las recomendaciones y sugerencias específicas para cada uo de los grupos de riesgo, aplicando los niveles de evidencia hallados en la literatura (AU)

In the past decade, ambulatory surgery has experienced a continuous increase, both in the types of procedures that are performed, as in the number of units qualified for outpatient surgery. One of the essential aspects in this development is the permanent improvement in the perioperative care that patients receive. In this regard, antithrombotic prophylaxis is of outstanding importance. Although the overall incidence of venous thromboembolism in these patients is not very high, the assessment of thrombosis risk factors, both personal and procedure related, is recommended. According to this risk assessment, patients may be stratified into low, moderate or high thrombotic risk categories. Therefore, thromboprophylaxis should be tailored to that risk: general measures alone, or combined with mechanical or pharmacological thromboprophylaxis. This multidisciplinary consensus document the recommendations of the Spanish Association of Major Ambulatory Surgery (ASECMA) published in 2011, and sets out evidence-based recommendations and specific suggestions for the each risk group (AU)

Desensitization Before Living Donor Kidney Transplantation in Highly HLA-Sensitized Patients: A Single-Center Study.

BACKGROUND: Renal transplantation in highly sensitized patients represents a major clinical challenge leading to long periods on the waiting list. When a living donor is available, the use of different strategies to desensitize recipients with preformed human leukocyte antigen antibodies can allow a successful transplantation. METHODS: We performed a retrospective observational study including all living donor kidney transplantation (LDKT) with desensitization (DS) from 2008 to 2014 in our transplant unit. The rates of rejection and graft survival were evaluated. DS consisted of plasma exchange (PE), rituximab (RTX), and intravenous immunoglobulin (IVIG) induction with thymoglobulin and maintenance immunosuppression with tacrolimus, corticosteroids, and mycophenolate mofetil. RESULTS: From 2008 to 2014, we performed 368 LDKT, with 31 receiving desensitization. Seven cases from a clinical trial were excluded. Demographic data and outcomes were recorded. All of the patients received RTX + PE + IVIG. DS was performed for positive complement-dependent cytotoxicity cross-match (4.2%), T-cell- and/or B-cell-positive flow cytometry cross-match (87.5%) and presence of donor-specific antibodies alone (8.3%). We identified 23 episodes of rejection in 12 patients (50%); 79% were antibody-mediated rejections (AMR). Graft failure was 12.5%, with a mean time to graft loss of 229 ± 203 days. Mean follow-up was 37 ± 27 months, and graft survival was 91% and 86% at 1 and 5 years, respectively. CONCLUSIONS: Desensitization in LDKT appears to offer an acceptable option for highly sensitized patients. In our series, 41% presented an AMR and 12.5% showed transplant glomerulopathy in protocol and/or indication biopsies. However, short-term outcomes and graft survival were satisfactory.

Preliminary study: fibre content in pet rabbit diets, crude fibre versus total dietary fibre.

Fibre is an important nutrient for rabbit health, and, on commercial pet rabbit packaging, it is labelled as crude fibre (CF). In several species, it is considered that CF is not an accurate representation of the fibre content in feedstuffs. The objective of this study was to compare the CF stated on the label (CFL) with laboratory analysis of CF (CFA) and the analysed content of total dietary fibre (TDF) in different commercial pet rabbit feeds. We selected 15 commercial diets and analysed CF and TDF. A mixed model was used to evaluate differences between CFL, CFA and TDF, and linear regression was performed to study the correlation between CFL and CFA with TDF. CFA and CFL were not significantly different (p = 0.836) in the feeds studied, and both were lower than TDF (p < 0.001). The correlations between TDF and both CFA and CFL were significant (p < 0.001 and p = 0.02, respectively), but the correlation was better with CFA (R = 0.86) than with CFL (R = 0.53). As expected, TDF content was higher than CF content, an average of two times. These results suggest that the CF content in rabbit diets reported on the label is not an appropriate indicator of their total fibre content, although further work with a larger sample size is required to confirm these results.

Immune system cells in healthy ferrets: an immunohistochemical study.

The ferret has emerged as an excellent animal model to characterize several physiologic and pathologic conditions. The distribution and characterization of different types of immune system cells were studied in healthy ferret tissues. Eight primary antibodies were tested for immunohistochemistry in formalin-fixed tissues: anti-CD3, anti-CD79α, anti-CD20, anti-HLA-DR, anti-lysozyme, anti-CD163, anti-SWC3, and anti-Mac387. The anti-CD3 antibody labeled T cells mainly in interfollicular and paracortical areas of lymph nodes, cortex and thymic medulla, and periarteriolar lymphoid sheaths in the spleen. The anti-CD79α and anti-CD20 antibodies immunolabeled B cells located in lymphoid follicles at lymph nodes, spleen, and Peyer patches. The CD79α and CD20 antibodies also labeled cells with nonlymphoid morphology in atypical B-cell locations. The anti-HLA-DR antibody labeled macrophages, some populations of B and T lymphocytes, and different populations of dendritic cells in lymph nodes, Peyer patches, spleen, and thymus. The anti-lysozyme antibody immunolabeled macrophages in the liver, lymph nodes, spleen, and thymus. The Mac-387, CD163, and SWC3 antibodies did not show any positive reaction in formalin-fixed or frozen tissues. To elucidate the origin of the uncommon CD79α/CD20 positive cells, a double immunohistochemistry was carried out using the anti-HLA-DR + the anti-CD79α, the anti-HLA-DR + the anti-CD20, and the anti-lysozyme + the anti-CD79α antibodies. Double labeling was mainly observed when the anti-HLA-DR + the anti-CD79α antibodies were combined. The immunohistologic characterization and distribution of these immune system cells in healthy ferret tissues should be of value in future comparative studies of diseases in ferrets.

Microcavity effects on the generation, fluorescence, and diffusion of excitons in organic solar cells.

We compute the short-circuit diffusion current of excitons in an organic solar cell, with special emphasis on fluorescence losses. The exciton diffusion length is not uniform but varies with its position within the device, even with moderate fluorescence quantum efficiency. With large quantum efficiencies, the rate of fluorescence can be strongly reduced with proper choices of the geometrical and dielectric parameters. Hence, through proper micro-cavity design, the diffusion length can be increased and the device performance significantly improved without recourse to triplet excitonic states.

Algorithms for the determination of unacceptable HLA antigen mismatches in kidney transplant recipients.

One of the major tasks of human leukocyte antigen (HLA) laboratories is the pretransplant determination of unacceptable HLA antigen mismatches (UAM) in organ transplant recipients. HLA antigen specificities are determined against which the patient has circulating alloantibodies that are expected to harm the transplanted organ. Using the information on UAM, negative crossmatch (XM) prediction or 'virtual XM' is possible when a potential donor's complete HLA typing is available. Before the introduction of solid-phase antibody detection assays, UAM were determined using the complement-dependent cytotoxicity methodology. After the introduction of the single antigen bead technique, however, various UAM determination algorithms have emerged. In this report, six different laboratories worldwide present how they determine UAM in their collective of kidney transplant recipients in the pretransplant phase and proceed thereafter to transplantation.

Histopathological alterations in Senegal sole, Solea Senegalensis, from a polluted Huelva estuary (SW, Spain).

As a component of a large research project to evaluate the effects of contaminants on fish health in the field, histopathological studies have been conducted to help establish causal relationship between pollutants (heavy metals and aromatic polycyclic hydrocarbons--PAHs) and histopathological responses in Senegal sole, Solea senegalensis, from an estuary of SW Spain. Heavy metals (As, Zn, Cd, Pb, Cu and Fe) and 16 PAHs (proprietary USEPA) concentrations in water, sediment and tissues (liver and gills) and histopathological alterations in S. senegalensis from three sampling sites of Ria de Huelva estuary during 2004-2006 years have been analysed. The histopathological studies revealed seasonal and spatial differences in the lesion grade of alterations observing the highest lesion grades in fish from Odiel River and autumn season. No significant differences were observed in the alterations prevalence between sampling sites, but significant differences were observed between seasons observing the highest prevalence in autumn season. However, calculated IPAT demonstrated a low-moderate impact of pollutants on health fish. Correlations between histopathological alterations and pollutants analysed were observed being heavy metals the group that presented a major number of correlations with alterations in several organs of S. senegalensis. In evaluating the general health of fish, the use of histopathological studies in recommended for making more reliable assessment of biochemical responses in fish exposed to a variety of environmental stressors. Statistical analysis using semiquantitative data on pathological lesions can help to establish correlation between cause (stressor) and effect (biomarker).

Polyphosphate binds to human von Willebrand factor in vivo and modulates its interaction with glycoprotein Ib.

BACKGROUND: Polyphosphate, a phosphate polymer released by activated platelets, has recently been described as a potent modulator of blood coagulation and fibrinolysis. In blood plasma, polyphosphate binds to and alters the biological functions of factor XII, fibrin(ogen), thrombin and factor VII activating protease. OBJECTIVES: The aim of the present study is to investigate whether polyphosphate also binds to von Willebrand factor (VWF) and alters some of its activities. METHODS/RESULTS: When studying patients with type 1 von Willebrand disease (VWD) and their healthy relatives, we discovered a significant correlation between von Willebrand factor (VWF) and platelet polyphosphate levels. We have also found polyphosphate in preparations of VWF isolated from normal platelets and plasma. Surface plasmon resonance and electrophoretic mobility assays indicated that polyphosphate interacts with VWF in a dose- and time-dependent manner. Treatment of normal plasma with active exopolyphosphatase decreased the VWF ristocetin cofactor (VWF:RCo) activity, a functional measure of VWF binding to platelet glycoprotein receptor Ib. VWF collagen binding and multimerization were unaltered after polyphosphate depletion. Moreover, addition of polyphosphate increased the deficient VWF:RCo activity presented by plasma from patients with type 1 VWD. CONCLUSIONS: Our results reveal that a new role is played by polyphosphate in hemostasis by its interaction with VWF, and suggest that this polymer may be effective in the treatment of some types of VWD.

Expression of myosin heavy chain isoforms in the human supraspinatus muscle: variations related to age and sex.

The contractile function of skeletal muscles is primarily regulated by the expression of myosin heavy chain (MHC) isoforms. Adult human skeletal muscles express three MHC isoforms (MHC-I, MHC-IIa and MHC-IIx). The muscles mainly expressing MHC-I are slow but resistant to fatigue, while those with major expression of MHC-IIa and MHC-IIx are fast and powerful but less resistant to fatigue. In this study, mRNA levels of the MHC isoforms were assessed in 24 human supraspinatus muscles by reverse-transcription polymerase chain reaction. The average expression of the MHC-I isoform was 36.72%, that of the MHC-IIa isoform was 33.52%, and the average expression of the MHC-IIx isoform was 29.76%. The higher average expression of the two MHC-II isoforms taken together (63.28%) indicates that the human supraspinatus muscle is a powerful, fast muscle with relatively low resistance to fatigue, in accordance with its role in the elevation of the upper extremity. In women, and more markedly in older women, the trend towards upregulation of the fast MHC-II isoforms and downregulation of the slow MHC-I isoform, which is absent in males, may improve our understanding of possible causes of the subacromial impingement syndrome.

Strategies to work with HLA data in human populations for histocompatibility, clinical transplantation, epidemiology and population genetics: HLA-NET methodological recommendations.

HLA-NET (a European COST Action) aims at networking researchers working in bone marrow transplantation, epidemiology and population genetics to improve the molecular characterization of the HLA genetic diversity of human populations, with an expected strong impact on both public health and fundamental research. Such improvements involve finding consensual strategies to characterize human populations and samples and report HLA molecular typings and ambiguities; proposing user-friendly access to databases and computer tools and defining minimal requirements related to ethical aspects. The overall outcome is the provision of population genetic characterizations and comparisons in a standard way by all interested laboratories. This article reports the recommendations of four working groups (WG1-4) of the HLA-NET network at the mid-term of its activities. WG1 (Population definitions and sampling strategies for population genetics' analyses) recommends avoiding outdated racial classifications and population names (e.g. 'Caucasian') and using instead geographic and/or cultural (e.g. linguistic) criteria to describe human populations (e.g. 'pan-European'). A standard 'HLA-NET POPULATION DATA QUESTIONNAIRE' has been finalized and is available for the whole HLA community. WG2 (HLA typing standards for population genetics analyses) recommends retaining maximal information when reporting HLA typing results. Rather than using the National Marrow Donor Program coding system, all ambiguities should be provided by listing all allele pairs required to explain each genotype, according to the formats proposed in 'HLA-NET GUIDELINES FOR REPORTING HLA TYPINGS'. The group also suggests taking into account a preliminary list of alleles defined by polymorphisms outside the peptide-binding sites that may affect population genetic statistics because of significant frequencies. WG3 (Bioinformatic strategies for HLA population data storage and analysis) recommends the use of programs capable of dealing with ambiguous data, such as the 'gene[rate]' computer tools to estimate frequencies, test for Hardy-Weinberg equilibrium and selective neutrality on data containing any number and kind of ambiguities. WG4 (Ethical issues) proposes to adopt thorough general principles for any HLA population study to ensure that it conforms to (inter)national legislation or recommendations/guidelines. All HLA-NET guidelines and tools are available through its website http://hla-net.eu.