Interplay between the genetic clades of Micromonas and their viruses in the Western English Channel.

The genus Micromonas comprises distinct genetic clades that commonly dominate eukaryotic phytoplankton community from polar to tropical waters. This phytoplankter is also recurrently infected by abundant and genetically diverse prasinoviruses. Here we report on the interplay between prasinoviruses and Micromonas with regard to the genetic diversity of this host. For 1 year, we monitored the abundance of three clades of Micromonas and their viruses in the Western English Channel, both in the environment using clade-specific probes and flow cytometry, and in the laboratory using clonal strains of Micromonas clades to assay for their viruses by plaque-forming units. We showed that the seasonal fluctuations of Micromonas clades were closely mirrored by the abundance of their corresponding viruses, indicating that the members of Micromonas genus are susceptible to viral infection, regardless of their genetic affiliation. The characterization of 45 viral isolates revealed that Micromonas clades are attacked by specific virus populations, which exhibit distinctive clade specificity, life strategies and genetic diversity. However, some viruses can also cross-infect different host clades, suggesting a mechanism of horizontal gene transfer within the Micromonas genus. This study provides novel insights into the impact of viral infection for the ecology and evolution of the prominent phytoplankter Micromonas.

Infection of nonhost species dendritic cells in vitro with an attenuated myxoma virus induces gene expression that predicts its efficacy as a vaccine vector.

Recombinant myxoma virus (MYXV) can be produced without a loss of infectivity, and its highly specific host range makes it an ideal vaccine vector candidate, although careful examination of its interaction with the immune system is necessary. Similar to rabbit bone marrow-derived dendritic cells (BM-DCs), ovine dendritic cells can be infected by SG33, a MYXV vaccine strain, and support recombinant antigen expression. The frequency of infected cells in the nonhost was lower and the virus cycle was abortive in these cell types. Among BM-DC subpopulations, Langerhans cell-like DCs were preferentially infected at low multiplicities of infection. Interestingly, ovine BM-DCs remained susceptible to MYXV after maturation, although apoptosis occurred shortly after infection as a function of the virus titer. When gene expression was assessed in infected BM-DC cultures, type I interferon (IFN)-related and inflammatory genes were strongly upregulated. DC gene expression profiles were compared with the profiles produced by other poxviruses in interaction with DCs, but very few commonalities were found, although genes that were previously shown to predict vaccine efficacy were present. Collectively, these data support the idea that MYXV permits efficient priming of adaptive immune responses and should be considered a promising vaccine vector along with other poxviruses.

[Streptococcus pyogenes endocarditis following varicella: a case report]. / Varicelle compliquée d'une endocardite à streptocoque A: à propos d'une observation.

Although varicella is most often a benign and self-limited disease of childhood, it can be associated with a variety of serious and potential lethal complications. Especially, the incidence of severe infectious complications caused by group A streptococci has been increasing over the last years. We report the case of a previously healthy young boy with an aortic bicuspidy who developed a varicella complicated by endocarditis due to group A streptococcus, and a haemophagocytic syndrome. A favorable outcome was obtained after an early valvular replacement and 6 weeks of intravenous antibiotics.

[HDL-cholesterol: role of its dosage in the assessment of cardiovascular risk]. / HDL-cholestérol: place de son dosage dans l'évaluation d'un risque cardiovasculaire.

The interest of HDL-cholesterol (HDLC) to evaluate a cardiovascular risk has been studied since many years. According to Framingham Heart studies, this factor is inversely correlated to a future ischaemic heart disease. At high level, HDLC is considered as a cardiovascular protecting factor, and is known since few years as "good cholesterol". In the year 2000, the ANAES (Agence nationale de l'accréditation et évaluation en santé) has redefined the role of HDLC in the exploration of dyslipidaemia. In the case of a cardiovascular-risk history, HDLC, with total cholesterol, triglycerides, and LDL-cholesterol (by Friedewald method) will be analyzed. Usually, HDLC is not very accessible to conventional treatments. So, according to ANAES, the treatment of dyslipidaemia will be based on LDL-cholesterol levels only. Nevertheless, HDLC is a major lipid factor to evaluate a cardiovascular risk. The object of this review is, on one hand, to situate HDLC in the evaluation of cardiovascular risk, by showing its key role in lipid metabolism, and, on the other hand, to report the main direct assays of this parameter.

[The "Limophoros": Polybius III, 87, 2]. / Le "Limophoros": Polybe III, 87, 2.

The word "limophoros", a hapax legomenon appearing in Polybius' Histories, does not mean scurvy, but rather scabies. Polybius created the word to describe an illness he believed was derived from a nutritional deficit, but can really only be seen as an attempt to describe an illness the etiology of which he was wholly unfamiliar.

[Cancers in children in the Auvergne area: retrospective study from 1986 to 1991]. / Les cancers de l'enfant dans la région Auvergne: étude rétrospective de 1986 à 1991*.

BACKGROUND: The specificity of childhood cancers led to the creation of regional childhood cancer registries. An epidemiological study of childhood cancers in the Auvergne area was carried out over a 6 year-period (1986-1991) in order to create a registry. POPULATION AND METHODS: The population of our study was 252,820 children (0-15 years old), living in the Auvergne region. All malignant neoplasms were included together with brain tumours (whatever grading). Data were collected from medical and administrative sources. RESULTS: The data of 153 cases were collected during this period. World age standardized overall incidence rate was 120.5 cases/milion/year. Age standardized incidence rates were: leukemias 37.6 (ALL 28.01), central nervous system tumours 18.34 (medulloblastomas 4.6, astrocytomas 4.6, ependymomas 3.8), lymphomas 10.0, neuroblastomas 18.6, soft tissue tumors 8.3, bone tumours 6.1 (Ewing's sarcomas 4.1, osteosarcomas 2.0), nephroblastomas 5.5, retinoblastomas 3.1, liver tumours 0.5 and others 0.5. CONCLUSIONS: Our data base in the Auvergne area might be a source of information for epidemiological studies on the role of etiological factors, the survival, the sequelae and the incidence trends.

A new case of partial trisomy 15q-.

Partial trisomy 15 was observed in a newborn with malformations of the head and extremities. A t(5;15) translocation was found in the mother and maternal grandfather.