[Responsibility due to medication errors in France: a study based on SHAM insurance data]. / Responsabilité liée aux erreurs médicamenteuses : données SHAM.

PURPOSE: The safe medication practices at the hospital constitute a major public health problem. Drug supply chain is a complex process, potentially source of errors and damages for the patient. SHAM insurances are the biggest French provider of medical liability insurances and a relevant source of data on the health care complications. METHODS: The main objective of the study was to analyze the type and cause of medication errors declared to SHAM and having led to a conviction by a court. We did a retrospective study on insurance claims provided by SHAM insurances with a medication error and leading to a condemnation over a 6-year period (between 2005 and 2010). RESULTS: Thirty-one cases were analysed, 21 for scheduled activity and 10 for emergency activity. Consequences of claims were mostly serious (12 deaths, 14 serious complications, 5 simple complications). The types of medication errors were a drug monitoring error (11 cases), an administration error (5 cases), an overdose (6 cases), an allergy (4 cases), a contraindication (3 cases) and an omission (2 cases). Intravenous route of administration was involved in 19 of 31 cases (61%). The causes identified by the court expert were an error related to service organization (11), an error related to medical practice (11) or nursing practice (13). Only one claim was due to the hospital pharmacy. CONCLUSION: The claim related to drug supply chain is infrequent but potentially serious. These data should help strengthen quality approach in risk management.

Length variations in the NA stalk of an H7N1 influenza virus have opposite effects on viral excretion in chickens and ducks.

A deletion of ∼20 amino acids in the stalk of neuraminidase is frequently observed upon transmission of influenza A viruses from waterfowl to domestic poultry. A pair of recombinant H7N1 viruses bearing either a short- or long-stalk neuraminidase was genetically engineered. Inoculation of the long-stalk-neuraminidase virus resulted in a higher cloacal excretion in ducks and led conversely to lower-level oropharyngeal excretion in chickens, associated with a higher-level local immune response and better survival. Therefore, a short-stalk neuraminidase is a determinant of viral adaptation and virulence in chickens but is detrimental to virus replication and shedding in ducks.

Methylation profile of the promoters of Nanog and Oct4 in ICSI human embryos.

STUDY QUESTION: What is the methylation status of the Nanog and Oct4 promoters in human gametes and ICSI embryos and is abnormal reprogramming of their methylation associated with developmental failure of ICSI embryos? SUMMARY ANSWER: Developmental failure of human ICSI embryos is associated with high methylation of the Oct4 promoter. WHAT IS KNOWN ALREADY: Nanog and Oct4 genes play critical roles in the establishment and maintenance of pluripotency during normal early embryonic development, and both are negatively regulated through the methylation of their promoters. STUDY DESIGN, SIZE AND DURATION: We analysed the methylation profile of Nanog and Oct4 promoters in 5 control sperm from normally fertile men, 70 metaphase II oocytes, 21 4-cell control ICSI embryos, 7 control blastocysts and 45 ICSI embryos arrested at 2- to 8-cell stage following prolonged culture. PARTICIPANTS, MATERIALS, SETTING AND METHODS: Embryos and gametes were donated for research by patients from the Department of Reproductive Medicine at the Hôpital Femme Mère Enfant (Bron, France) and the Clinique du Tonkin (Villeurbanne, France) after giving their informed consent. MAIN RESULTS: For both promoters, high methylation was observed in sperm cells. Although, in general, the promoters were unmethylated in oocytes, the methylation of some alleles was observed, particularly in oocytes from women with known infertility. Both gene promoters were hypomethylated in control blastocyst ICM (inner cell mass) and in control 2-8-cells embryos obtained from 6 out of 8 couples. However, they appeared highly methylated in embryos obtained from the other two couples. In most arrested ICSI embryos, the Nanog promoter was unmethylated while the Oct4 promoter was highly methylated. High methylation of the Oct4 promoter was significantly more pronounced in embryos from couples where a male factor was the only known cause of infertility. When the embryos were heterozygous for a G/A single nucleotide polymorphism, both alleles could be methylated, each likely representing a paternally inherited or a maternally inherited copy. LIMITATIONS AND REASONS FOR CAUTION: The study was done on a limited number of oocytes and embryos and the gametes of the couples were not available. WIDER IMPLICATIONS OF THE FINDINGS: These results provide new insight regarding the roles of epigenetic abnormalities in early developmental failure in humans. STUDY FUNDING/COMPETING INTEREST(S): No external funding was obtained for this study. There was no competing interest.

A case of unilateral periorbital cellulitis and mandibular osteomyelitis in a turkey flock.

A farm of meat turkeys was affected by a condition, clinically characterized by unilateral inflammation of the orbital region and progressive crossing of the beak, observed in three successive flocks in 2010. While no toxic, genetic, technical, or diet causes could be found, pathologic and bacteriologic analyses were conducted to investigate the case. Pathologic analyses of the heads of affected birds showed blepharitis and exudative sinusitis as well as severe chronic osteomyelitis of all skull bones and mandibula. Staphylococcus aureus was consistently isolated from these lesions. It is supposed that the severe bacterial osteomyelitis induced deviation of some bones, thereby leading to deviation of the beak. Further investigations remain to be carried out to explain these successive outbreaks of staphylococcal osteomyelitis in skull bones.

Aneuploidy rate in spermatozoa of selected men with severe teratozoospermia.

The aim of this study was to evaluate the incidence of spermatic aneuploidies in men with severe teratozoospermia and to determine an eventual relation between aneuploidies and a specific morphology of spermatozoa. Fluorescence in situ hybridisation (FISH) using a probe cocktail containing the alpha satellite for the centromeric region of chromosome X, Y and 18 was performed on decondensed spermatozoa from fresh ejaculates of thirty patients with severe teratozoospermia (abnormal forms >80%) and 15 fertile men with normal semen profiles. The mean frequency of teratozoospermia in patients was 91 ± 6.99%. There was statistically a significantly increased frequency of 1818, XY, XX and YY disomies in sperm with severe teratozoospermia compared with normal sperm (1.24% versus 0.08%, 1.42% versus 0.31%, 1.13% versus 0.19% and 1.11% versus 0.24%, respectively, P < 0.001 in all comparisons). The rate of total diploidy was significantly increased in patients compared with controls (1.46% versus 0.16%, P < 0.001). There was a correlation between macrocephalic spermatozoa and diploidy (r = 0.37, P < 0.05). Our data add further evidence that patients with severe teratozoospermia have an increased sperm aneuploidy rate and that this is particularly high in macrocephalic spermatozoa; FISH analysis on sperm could help to improve risk assessment and reproductive counselling in these individuals who are frequently candidates for intracytoplasmic sperm injection (ICSI) as a treatment of their infertility, as the use of ICSI has created consequential debate concerning the genetic risk for the offspring.

Retinoblastoma: What the Neuroradiologist Needs to Know.

Retinoblastoma is the most common primary intraocular tumor of childhood. Accurate diagnosis at an early stage is important to maximize patient survival, globe salvage, and visual acuity. Management of retinoblastoma is individualized based on the presenting clinical and imaging features of the tumor, and a multidisciplinary team is required to optimize patient outcomes. The neuroradiologist is a key member of the retinoblastoma care team and should be familiar with characteristic diagnostic and prognostic imaging features of this disease. Furthermore, with the adoption of intra-arterial chemotherapy as a standard of care option for globe salvage therapy in many centers, the interventional neuroradiologist may play an active role in retinoblastoma treatment. In this review, we discuss the clinical presentation of retinoblastoma, ophthalmic imaging modalities, neuroradiology imaging features, and current treatment options.

Hypothalamic Pilomyxoid Astrocytoma in a Child with Lipodystrophy.

Pilomyxoid astrocytoma is a rare form of pediatric CNS malignancy first classified in 2007 by the World Health Organization. The tumors are similar to pilocytic astrocytomas, sharing both some imaging and histologic traits. However, pilomyxoid astrocytomas portend a more ominous prognosis, with more aggressive local tendencies and a greater proclivity for leptomeningeal spread. Although tissue sampling is ultimately required to differentiate pilocytic astrocytomas and pilomyxoid astrocytomas, some imaging features can be used to suggest a pilomyxoid astrocytoma, including homogeneous enhancement, leptomeningeal seeding, and lack of intratumoral cysts. In this article, a case of a hypothalamic pilomyxoid astrocytoma is described, in which the presenting disorder was profound generalized lipodystrophy. The aforementioned imaging characteristics of pilomyxoid astrocytomas are reviewed, as are the pathologic features of such tumors, including their angiocentric cellular arrangement and myxoid background.

Combining immunotherapy with an epidrug in squamous cell carcinomas of different locations: rationale and design of the PEVO basket trial.

Squamous cell carcinomas (SCCs) are among the most frequent solid tumors in humans. SCCs, related or not to the human papillomavirus, share common molecular features. Immunotherapies, and specifically immune checkpoint inhibitors, have been shown to improve overall survival in multiple cancer types, including SCCs. However, only a minority of patients experience a durable response with immunotherapy. Epigenetic modulation plays a major role in escaping tumor immunosurveillance and confers resistance to immune checkpoint inhibitors. Preclinical evidence suggests that modulating the epigenome might improve the efficacy of immunotherapy. We herein review the preclinical and the clinical rationale for combining immunotherapy with an epidrug, and detail the design of PEVOsq, a basket clinical trial combining pembrolizumab with vorinostat, a histone deacetylase inhibitor, in patients with SCCs of different locations. Sequential blood and tumor sampling will be collected in order to identify predictive and pharmacodynamics biomarkers of efficacy of the combination. We also present how clinical and biological data will be managed with the aim to enable the development of a prospective integrative platform to allow secure and controlled access to the project data as well as further exploitations.

Cervicofacial Venous Malformations Are Associated with Intracranial Developmental Venous Anomalies and Dural Venous Sinus Abnormalities.

BACKGROUND AND PURPOSE: Prior studies have suggested an association between the presence of cervicofacial venous malformations and intracranial developmental venous anomalies. We reviewed our institutional cohort of patients with cervicofacial venous malformations and examined the spectrum of intracranial venous anomalies, including developmental venous anomalies, cavernous malformations, and dural venous sinus abnormalities. MATERIALS AND METHODS: Consecutive patients who presented to our institution with cervicofacial venous malformations and underwent postcontrast MR imaging were studied. Three neuroradiologists reviewed brain MRIs for the presence of developmental venous anomalies, dural venous sinus ectasia, and cavernous malformations. The prevalence of developmental venous anomalies in this patient population was compared with an age- and sex-matched control group without venous malformations at a ratio of 1:2. Categoric variables were compared with χ2 tests. RESULTS: Sixty-three patients with venous malformations met the inclusion criteria with a mean age of 38.3 ± 24.0 years. The overall presence of developmental venous anomalies in patients with venous malformations was 36.5% (23/63) compared with 7.9% (10/126) in controls (P < .001). The prevalence of dural venous sinus ectasia was 9.5% (6/63) compared with 0% for controls (P = .002). One patient with a venous malformation had a cavernous malformation compared with 1 patient in the control group (P = .62). In 73.9% of patients (17/23), developmental venous anomalies were along the same metamere; and in 82.6% of patients, developmental venous anomalies were ipsilateral to the venous malformations. CONCLUSIONS: Our case-control study demonstrated a significant association between cervicofacial venous malformations and cerebral developmental venous anomalies as well as between cervicofacial venous malformations and dural venous sinus abnormalities. Our findings suggest that venous malformations may be the result of a segmental in utero insult to cells involved in cerebrofacial venous development.

The Forgotten Second Window: A Pictorial Review of Round Window Pathologies.

The round window serves to decompress acoustic energy that enters the cochlea via stapes movement against the oval window. Any inward motion of the oval window via stapes vibration leads to outward motion of the round window. Occlusion of the round window is a cause of conductive hearing loss because it increases the resistance to sound energy and consequently dampens energy propagation. Because the round window niche is not adequately evaluated by otoscopy and may be incompletely exposed during an operation, otologic surgeons may not always correctly identify associated pathology. Thus, radiologists play an essential role in the identification and classification of diseases affecting the round window. The purpose of this review is to highlight the developmental, acquired, neoplastic, and iatrogenic range of pathologies that can be encountered in round window dysfunction.

Prospective evaluation of the threat related to the use of seminal fractions from hepatitis C virus-infected men in assisted reproductive techniques.

BACKGROUND: The risk of hepatitis C virus (HCV) transmission during assisted reproductive techniques (ARTs) is still disputed and no report concerning its prospective evaluation is available. METHODS: The aim of this 4-year follow-up multicentre study that enrolled 86 HCV-serodiscordant couples was to determine whether a sperm-processing method was able to reduce levels of HCV in semen and the risk of HCV transmission to the newborn. All the men were chronically infected by HCV and 10 of them by human immunodeficiency virus. A total of 181 seminal plasmas and 153 sperm fractions were tested for the presence of HCV RNA. RESULTS: HCV RNA tested positive in 20.4% of the seminal samples. All of the 153 final sperm fractions tested negative for HCV. The detection of HCV RNA in semen was significantly correlated with a high viral load in blood (P < 0.05). The presence of HCV RNA in seminal plasma impaired neither semen parameters nor ART issue. From the 58 couples enrolled effectively in an ART programme, 24 pregnancies and 28 newborns were obtained. All of them tested negative for HCV RNA in blood. CONCLUSION: These results emphasize the safety of the semen-processing method. The negligible risk of transmitting HCV reduces the value of the systematic analysis of HCV RNA in seminal fractions prior to ART. Since use of this analytical procedure involves the freezing of semen, its avoidance would result in an increase in sperm quality and reduce the need to perform intracytoplasmic sperm injection techniques.

Dynamic CpG methylation of the KCNQ1OT1 gene during maturation of human oocytes.

BACKGROUND: Imprinted genes, many of which are involved in development, are marked during gametogenesis to allow their parent-of-origin specific expression, and DNA methylation at CpG islands is part of this epigenetic mark. Maternal imprint is apposed on oocyte during growth and maturation. Factors interfering with normal oocyte differentiation such as gonadotrophin stimulation and in vitro maturation (IVM) may possibly alter imprint resetting. METHODS: We examined the methylation of the KCNQ1OT1 differentially methylated region (KvDMR1) in human oocytes at different stages of their development: germinal vesicle (GV), metaphase I (MI) or metaphase II (MII). RESULTS: About 60% of alleles were fully methylated in GV oocytes and that full imprint is acquired in most MII oocytes. Similarly to in vivo, de novo methylation of DNA occurred in vitro during oocyte maturation. Following in vitro culture for 28 h, GV and MI oocytes are significantly more methylated when they are obtained from natural cycles than from patients undergoing gonadotrophin stimulation. CONCLUSION: This observation suggests that hyperstimulation likely recruits young follicles that are unable to acquire imprint at KvDMR1 during the course of the maturing process.

[The Bcl-2 family pathway in gametes and preimplantation embryos]. / Les régulateurs d'apoptose de la famille Bcl-2 dans les gamètes et lors du développement embryonnaire précoce.

Apoptosis, a form of cell death by self-destruction, has been reported in gametes and preimplantation embryos both in vitro and in vivo. Recent evidence suggests that cell death processes, whose control deserves to be elucidated, can impact embryo developmental competence. Moreover, quality of the gametes (particularly of the oocytes) is relevant not only for their survival rates but exert an influence during the early stages of embryo development. Thus, the investigation of apoptosis-related genes and mechanisms in early embryos is crucial. BCL-2 family proteins, through balanced interactions between pro- and anti-death members, play a pivotal role in controlling cell life and death. In this article, we review the literature concerning the expression of Bcl-2 family members in gametes and early embryos. Research results indicate that the various Bcl-2 subfamilies (pro- and anti-apoptotic "multidomain" family members and "BH3-only" death factors) exhibit a dynamic expression pattern during male and female gamete differentiation and early embryo development. While pro-apoptotic Bax protein plays a critical role in germ cell and early embryo degeneration, the relative importance of the prosurvival (Bcl-2, Bcl-xL, Bcl-w, Mcl-1) and "BH3-only" (Bim, Bad, Bik) members is not clear. Although information on expression patterns of Bcl-2 family transcripts and proteins is necessary, other elements such as transcriptional control (by environmental stimuli), subcellular localization and post-translational modifications should also be taken into account. Aside from basic research, a better understanding of apoptosis-related proteins and mechanisms involved in gamete and embryo viability at the molecular level may provide new guides for diagnosis and therapeutic strategies.

[Study of the junction between the cortical bridging veins and basal cranial venous sinus]. / Etude anatomique du drainage des veines corticales inférieures dans le sinus transverse.

INTRODUCTION: The cerebral venous system is poorly known and is best appreciated based on macroscopic anatomical considerations. We present an anatomical and immunohistochemical study to better define the morphological characteristics of the junction between the inferior cortical veins and the transversal sinuses. MATERIAL AND METHODS: Sixteen cadaveric specimens from the anatomy laboratory of the University Victor-Segalen of Bordeaux were studied. The venous junctions with the transversal sinuses were observed under the operating microscope. Thirty vein-sinus junctions were immunohistochemically stained with smooth muscle actin. Ten venous junctions were observed under the electronic microscope. RESULTS: The inferior cortical veins drain into the transverse sinus either directly or through a tentorial sinus. The venous orifices in the transverse sinuses share the same characteristics. They are oval with semicircular superior dural reinforcement and follow an orientation opposite venous flow in the transversal sinus. The histologic study showed that the walls of the cortical veins contained smooth muscle cells as well as the dural reinforcement of the transversal sinuses. CONCLUSION: The venous orifices of the inferior cortical veins have the anatomical features of true sphincters. Their function in the regulation of the cerebral blood flow needs further exploration.

Duck production systems and highly pathogenic avian influenza H5N8 in France, 2016-2017.

In winter 2016-2017, Highly Pathogenic Avian Influenza (HPAI) H5N8 virus spread across Europe, causing unprecedented epizootics. France was massively affected, resulting in the culling of over 6 million poultry. Boosted regression tree (BRT) models were used to quantify the association between spatial risk factors and HPAI H5N8 infection in poultry holdings and to generate predictive maps for HPAI infection. Three datasets were combined to build the model: a dataset of the reported outbreaks in poultry, a dataset of the poultry holdings where the virus has not been reported and a set of relevant spatial risk factors, including poultry production and trade, and water bird habitat. Results identified key associations between the 'foie gras' production systems and HPAI H5N8 risk of occurrence and indicate that strengthening surveillance of fattening duck production systems and making the transportation of fattening ducks more secure would be key priority options for HPAI prevention and control.

Food Matrix Design for Effective Lactic Acid Bacteria Delivery.

The range of foods featuring lactic acid bacteria (LAB) with potential associated health benefits has expanded over the years from traditional dairy products to meat, cereals, vegetables and fruits, chocolate, etc. All these new carriers need to be compared for their efficacy to protect, carry, and deliver LAB, but because of their profusion and the diversity of methods this remains difficult. This review points out the advantages and disadvantages of the main food matrix types, and an additional distinction between dairy and nondairy foods is made. The food matrix impact on LAB viability during food manufacturing, storage, and digestion is also discussed. The authors propose an ideal hypothetical food matrix that includes structural and physicochemical characteristics such as pH, water activity, and buffering capacities, all of which need to be taken into account when performing LAB food matrix design. Guidelines are finally provided to optimize food matrix design in terms of effective LAB delivery.

Exploring the Wind-Borne Spread of Highly Pathogenic Avian Influenza H5N8 During the 2016-2017 Epizootic in France.

In winter 2016-2017, highly pathogenic avian influenza (HPAI) H5N8 virus spread in France, causing an unprecedented epizootic. During the epidemic, southwest France, where most outbreaks were reported, experienced severe weather, with three consecutive storms (Leiv, Kurt, and Marcel) from 3 to 5 February 2017. Although little information is available, one hypothesis is that the spread of HPAI-H5N8 from an infected poultry holding could have been passively facilitated by prevailing wind during the risk period. The aim of this study was therefore to assess the contribution of the wind-borne route to the spatial distribution of HPAI H5N8 outbreaks during the risk period at the beginning of February 2017. The PERLE model, an atmospheric dispersion model (ADM) developed by Météo-France, the French meteorological agency, was used to generate the predicted area at risk of infection from a suspected point source. Model outputs show that the spatial pattern of dust-particle deposition was directed east-southeast in accordance with wind direction. This contrasted with the spatial distribution of HPAI H5N8 outbreaks, which spread westward. These observations suggest that the wind-borne route alone was insufficient to explain the spatial distribution of outbreaks over large distances in southwest France at the beginning of February 2017. Finally, this study illustrates the relevance of close collaboration between governmental authorities, veterinary research institutes, and meteorological agencies involving interdisciplinary research for successful outbreak investigations.

Nota de investigación- Exploración de la propagación por el viento del virus de la influenza aviar altamente patógena H5N8 durante la epizootia entre los años 2016­2017 en Francia. En el invierno 2016-2017, el virus de la influenza aviar altamente patógena subtipo H5N8 se propagó en Francia y causó una epizootia sin precedentes. Durante la epidemia, en el suroeste de Francia, donde se registraron la mayoría de los brotes, se registró clima severo, con tres tormentas consecutivas (Leiv, Kurt y Marcel) del 3 al 5 de febrero del 2017. Aunque hay poca información disponible, una hipótesis es que la propagación del virus de influenza aviar de alta patogenicidad H5N8 desde una explotación avícola infectada podría haberse facilitado pasivamente por los vientos dominantes durante el período de riesgo. El objetivo de este estudio fue, por lo tanto, evaluar la contribución de la ruta del viento en la distribución espacial de los brotes de influenza aviar de alta patogenicidad H5N8 durante el período de riesgo a principios de febrero del 2017. El modelo PERLE, un modelo de dispersión atmosférica (ADM) desarrollado por la agencia meteorológica francesa Météo-France, fue utilizado para generar el área pronosticada en riesgo de infección a partir de una fuente sospechosa. Los resultados del modelo muestran que el patrón espacial de la deposición de partículas de polvo se dirigió al este-sureste de acuerdo con la dirección del viento. Esto contrastó con la distribución espacial de los brotes de influenza aviar de alta patogenicidad H5N8, que se extendieron hacia el oeste. Estas observaciones sugieren que la ruta por el viento por sí sola no fue suficiente para explicar la distribución espacial de los brotes en grandes distancias en el suroeste de Francia a principios de febrero de 2017. Finalmente, este estudio ilustra la relevancia de la estrecha colaboración entre las autoridades gubernamentales, los institutos de investigación veterinaria y agencias meteorológicas, que se involucren en investigación interdisciplinaria para la investigación exitosa de los brotes.

Mixed Solid and Cystic Mass in an Infant.

Desmoplastic infantile tumors are rare supratentorial brain tumors that occur in pediatric patients. Desmoplastic infantile tumors are made up of 2 subtypes: desmoplastic infantile gangliogliomas and desmoplastic infantile astrocytomas. Desmoplastic infantile tumors are often identifiable on imaging on the basis of multiple characteristics. Nevertheless, pathologic analysis is required to confirm the diagnosis, particularly when the imaging features are atypical. Here, the radiology findings, surgical approach and subsequent management, and pathology of a desmoplastic infantile ganglioglioma are described.

Specific hypermethylation of LINE-1 elements during abnormal overgrowth and differentiation of human placenta.

In human post-natal somatic cells, low global levels of DNA methylation have been associated with the hypomethylation of several repetitive elements, a feature that has been proposed to be a surrogate epigenetic marker. These data, mainly derived from the analysis of cancer cells, suggest a potential association between loss of cell-growth control and altered differentiation with hypomethylation of repetitive sequences. Partial hydatidiform moles (PHMs) can be used as an alternative model for investigating this association in a non-tumorigenic context. This gestational disease is characterized by abnormal overgrowth and differentiation of the placenta and spontaneous abortion. Here, we comprehensively analyse the DNA methylation of these trophoblastic tissues in both PHM and normal placenta at global and sequence-specific levels. Analysis of the global 5-methylcytosine content and immunohistochemistry indicate that PHM and normal placenta have identical global levels of DNA methylation. In contrast, bisulfite genomic sequencing shows that, whereas Alu, NBL2 and satellite 2 repetitive elements are equally methylated, LINE-1 sequences are hypermethylated in PHM tissues ( approximately 2-fold relative to normal placenta). Interestingly, altered demethylation is also found in triploid diandric embryos that originate from dispermic fertilization of an oocyte, a common event responsible for most PHMs. In conclusion, alterations of DNA methylation do not seem to be randomly distributed in PHM, as several repeated elements remain unaltered, whereas LINE-1 sequences are hypermethylated. In addition, our findings suggest that the hypomethylation of repetitive elements in cancer is directly linked to the neoplasic process and not a simple consequence of loss of growth control observed in most of the cancer cells.

Junction between the great cerebral vein and the straight sinus: an anatomical, immunohistochemical, and ultrastructural study on 25 human brain cadaveric dissections.

The cerebral venous system is poorly understood, and best appreciated under macroscopic anatomical considerations. We present an anatomical and immunohistochemical studies to better define the morphological characteristics of the junction between the great cerebral vein and the straight sinus. Twenty-five cadaveric specimens from the anatomy laboratory of the University Victor Segalen of Bordeaux were studied. The observation of the venous junctions with the straight sinus was performed under an operating microscope. The smooth muscular actin immunohistochemical staining was performed for 18 veno-sinosal junctions. Five venous junctions were observed using an electron microscope. We observed 3 different anatomic aspects: type 1 was a junction with a small elevation in its floor and a posterior thickening (14 cases); type 2 was a junction with an outgrowth on the floor like a cornice (7 cases); and type 3 was a junction presenting a nodule. Microscopic study of type 1 and 2 junctions showed a positive coloration to orceine attesting the presence of elastic fibers. Immunohistochemistry revealed the presence of smooth muscular actin and S 100 protein attesting the presence of smooth muscular fibers and nervous fibers. We observed in the ultrastructural study, a morphological progression of the endothelium. The venous orifice of the great cerebral vein into the straight sinus could be anatomically assimilated as a true "sphincter." Its function in the regulation of the cerebral blood flow needs further exploration.