The effects of decanted sediments on embryogenesis in oysters (Crassostrea gigas)

Sediments act as sinks for contaminants of natural and anthropogenic origin, constituting a risk to the living organisms. In this study, sediments were collected from three sites on the coast of southwest France. The objective of this research was to determine the effects of sediments on embryonic development of bivalves and to identify precisely when the contaminants affect the embryos and induce them to develop in an abnormal way. The toxicity of decanted sediments and overlying waters were assessed using the oyster embryo bioassay. The physical characteristics and contaminant levels in the sediments were measured, including polycyclic aromatic hydrocarbon (PAH) and metal concentrations. Despite contaminant concentrations for PAH and metals only exceeding the effects range-low levels, all decanted sediments tested induced deleterious effects on the embryonic development of oysters, while no significant abnormalities were observed for overlying waters. The study results suggest that abnormal larvae mainly are caused by direct contact with contaminated sediments.     

Molecular characterization of serotype III group B-streptococcus isolates causing neonatal meningitis

We studied a collection of 110 serotype III group B streptococcus (GBS) isolates causing neonatal meningitis, by means of both pulsed-field gel electrophoresis (PFGE) with SmaI and Southern hybridization with probes for genes potentially associated with virulence (neuA, cpsA, scpB, and hylB and, for mobile genetic elements [MGEs], GBSi1 and IS1548), in comparison with 44 serotype III GBS isolates colonizing healthy neonates. Using polymerase chain reaction, we assessed both the insertion of MGEs downstream of the scpB gene and the insertion of IS1548 within the hylB gene. PFGE clustered the isolates into 3 main groups. One PFGE group accounted for 80% of typeable cerebrospinal fluid (CSF) isolates, versus 24% of colonization isolates (P=1.8 x 10-9). GBSi1 was found in 67% of CSF isolates and in only 23% of colonization isolates (P=5.3 x 10-7). A 15-kbp SmaI restriction-DNA fragment bearing the neuA gene was significantly associated with CSF isolates (P=1.1 x 10-11).     

Mechanisms involved in methylmercuric chloride (MeHgCl)-induced suppression of human neutrophil apoptosis

We have previously demonstrated that concentrations of 1-10 microM of methylmercuric chloride (MeHgCl) that are cytotoxic to monocytes-macrophages can curiously inhibit neutrophil apoptosis by a yet unknown mechanism. In the present study, we demonstrate that, as with the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF), a classical inhibitor of neutrophil apoptosis, treatment of cells with 5 microM MeHgCl induces de novo protein synthesis and prevents the loss of expression of the antiapoptotic Mcl-1 protein. The expression of the cytoskeletal proteins gelsolin, paxillin and vinculin was similar in MeHgCl- or GM-CSF-induced suppression of apoptosis. However, MeHgCl prevents the degradation of vimentin differently than GM-CSF. Apoptosis was further confirmed by flow cytometry (FITC annexin-V), and by monitoring CD16 cell surface expression. Curiously, unlike GM-CSF, MeHgCl did not prevent CD16 shedding. We conclude that, like GM-CSF, MeHgCl can delay neutrophil apoptosis by inducing de novo protein synthesis and by preventing the loss of the antiapoptotic Mcl-1 protein. However, unlike GM-CSF, MeHgCl induces an atypical degradation of vimentin without preventing CD16 shedding.     

Epidemiological features of tumors of the skin and mucosal membranes in the department of dermatology at the Yalgado Ouedraogo National Hospital, Ouagadougou, Burkina Faso

We conducted a retrospective study of the files of all patients seen from 1 January 1992 through 31 December 1996 with tumors of the skin and mucosal membranes at the Yalgado Ouédraogo National Hospital in order to determine the epidemiologic features of this disease. The records revealed 988 patients presented 1024 tumors, which could be classified into 33 categories. Most of the patients (60.6%) were in the age bracket of 20 to 39 years. Nearly all cases (988 or 96.5%) were benign skin tumors, mainly of infectious origin, especially viral (51.7%). We observed a substantial number of sexually transmissible infections, such as condylomata. We also found 36 cases (3.5%) of malignant tumors, including 29 cases of Kaposi sarcoma, five skin carcinoma (13.8%), three spinocellular and two basocellular; we also noted two borderline malignant tumors: a dermatofibrosar-coma protuberans and a nodular hidradenoma. The elevated prevalence of condyloma (151 cases) may explain the predominance of the 20-39 year age group, which is the most sexually active. Our series also confirmed the relative rarity (3.5%) of cutaneous cancers among African blacks. The predominance of Kaposi sarcoma may be explained by the high prevalence of HIV infection in our country.     

Prenatal diagnosis of respiratory chain deficiency by direct mutation screening

Respiratory chain deficiency (RCD) is responsible for a clinically heterogeneous group of early-onset untreatable disorders. Enzymological prenatal diagnosis (PD) can only be offered to a fraction of families. Moreover, due to the two-fold genetic origin of the respiratory chain (nuclear and mitochondrial DNA) and owing to the large number of nuclear genes involved in the respiratory chain assembly, maintenance and functioning, the identification of the disease causing gene in a given family remains challenging. Here, we report on PD of RCD by direct screening of NDUFV1, SDH-Fp, SCO1 and SURF1 mutations in five unrelated families with complex I, II and IV deficiency, respectively. The identification of the disease-causing gene in a given family with RCD is a major issue to provide both adequate genetic counselling and early, reliable PD.     

Usefulness of gamma intracoronary radiation for totally occluded in-stent restenotic coronary narrowing

This is the first study to demonstrate the appearance of the Fibonacci Cascade within the distribution of coronary artery lesions in the human heart. The propensity for this ratio to appear in nature may also be because this ratio optimizes the efficiency of packing structures in a limited space in such a way that wasted space is minimized and the supply of energy or nutrients is optimized.     

Levetiracetam: preliminary efficacy in generalized seizures

Levetiracetam is a novel antiepileptic drug (AED) with proven efficacy against partial seizures, but there is limited information about its effectiveness against generalized seizures. In animal models, levetiracetam protects against seizures in audiogenic susceptible rodents, and it is effective in the Genetic Absence Epilepsy Rat from Strasbourg, a model of absence seizures. In these models, levetiracetam has a therapeutic index that is higher than those of other AEDs. A number of small open-label studies suggest that levetiracetam reduces seizure frequency in patients with generalized seizures, including primarily generalized seizures and myoclonic seizures. Case reports provide additional information regarding the potential efficacy of levetiracetam in postanoxic, post-encephalitic and progressive myoclonus. Although random-ized controlled studies of patients with generalized seizures have not yet been conducted, on the basis of available information, levetiracetam may be prom-ising in the treatment of generalized seizures.     

Chemotherapy by fotemustine in cerebral metastases of disseminated malignant melanoma

Summary A total of 42 patients with cerebral metastases of malignant melanoma were included in this study of the nitrosourea fotemustine. The treatment plan consisted of a 1-h i. v. infusion of 100 mg/m² fotemustine every week for 3–4 weeks, followed by a 4- to 5-week rest period. Responding or stabilised patients then received 100 mg/m² fotemustine every 3 weeks. Among the 39 evaluable patients, 2 complete responses and 9 partial responses were documented, leading to an overall response rate of 28.2%. Most of the responses were obtained in previously untreated patients and/or those presenting with a single cerebral metastasis. Toxicity was mild and mainly hematological, especially in patients previously treated by polychemotherapeutic regimen. Our study confirms the activity of fotemustine in cerebral metastases of disseminated malignant melanoma.Others institutions involved in this trial: A. Bernadou, Hôtel Dieu, Paris; J. Clavier, CHR de Brest; M. Delaunay, Hôpital Pellegrin Tripode, Bordeaux; J. P. Escande, Hôpital Tarnier, Paris; P. Fargeot, Centre George François Leclerc, Dijon; P. Lauret, Hôpital Charles Nicolle, Rouen; R. Leblay, Hôpital Sud, Rennes; P. Litoux, CHR de Nantes; G. Lorette, Hôpital Trousseau, Tours; R. Metz, Centre Alexis Vautrin, Nancy; A. Monnier, CHR Boulloche, Montbelliard; M. Mousseau, CHR de la Tronche, Grenoble; J. P. Olivier, Hôpital Dupuytren, Limoges; R. Touraine, Hôpital Henri Mondor, Créteil; F. Truchetet, Hôpital de Thionville, France     

Modulation of the Interleukin 2 Receptor by Maternal and Cord Blood Serum

In this report, the potential inhibitive action, of maternal serum (retroplacental and peripheral), and cord blood serum on the expression of the I12r has been studied. Calf and male serum were used as a control. In order to have an optimal I12r expression, a previous PHA cellular stimulation was performed. the maternal serum's I12r inhibitive property was measured during and after the pregnant period. the presence of I12r on maternal lymphocytes, cord blood cells, and unrelated donor mononuclear cells has been investigated (after a PtfA stimulation assay). the down regulated Il2r expression of neoplastic cell line (Hut7g cell line) under the influence of maternal serum has been observed. the examination of the inhibitive action due to maternal serum has suggested that a factor included in the IgG fraction is mainly responsible for the down regulating property concerning the 112r expression. A possible mechanism for the action of this factor has been studied. Further experiments suggest that the addition of recombinant I12 during the action of low doses of maternal IqG allows a partial reexpression of the I12 receptor. However, at. physiological concentrations of IyC, thc Interleukin 2 receptor down regulation becomes Irreversible.