[Orthoreoviruses: are they pathogenic for man?] / Les orthoréovirus : virus orphelins ou pathogènes chez l'homme ?

The orthoreoviruses are segmented double strand RNA viruses and are the most abundant viruses in nature. Three main serotypes are known, named 1, 2 and 3. The designation "reovirus" is the acronym for "respiratory enteric orphan virus", expression underlining their respiratory and enteric origin and the fact that they are not associated with well defined clinical disease. Nevertheless, strains of orthoreoviruses have been isolated from several cases of symptomatic diseases in human, namely diseases of the central nervous system such as encephalitis and meningitis sometimes leading to patient death. These different cases show that orthoreoviruses could be pathogenic, causing fatal diseases. Orthoreoviruses infection in animals induces also several diseases. Indeed, according to the inoculation route and the serotype of inoculated strain, encephalitis or hepatitis can be observed. The RNA segments M2 and S1 seem to be involved in this neurovirulence property and are on the basis of cellular mechanisms, such as virus entry, virus replication and apoptosis. However, the mechanisms of virulence remain complex.

The European Virus Archive goes global: A growing resource for research.

The European Virus Archive (EVA) was created in 2008 with funding from the FP7-EU Infrastructure Programme, in response to the need for a coordinated and readily accessible collection of viruses that could be made available to academia, public health organisations and industry. Within three years, it developed from a consortium of nine European laboratories to encompass associated partners in Africa, Russia, China, Turkey, Germany and Italy. In 2014, the H2020 Research and Innovation Framework Programme (INFRAS projects) provided support for the transformation of the EVA from a European to a global organization (EVAg). The EVAg now operates as a non-profit consortium, with 26 partners and 20 associated partners from 21 EU and non-EU countries. In this paper, we outline the structure, management and goals of the EVAg, to bring to the attention of researchers the wealth of products it can provide and to illustrate how end-users can gain access to these resources. Organisations or individuals who would like to be considered as contributors are invited to contact the EVAg coordinator, Jean-Louis Romette, at jean-louis.romette@univmed.fr.

Comparative analysis of HTLV-I promoter activities reveals no disease-linked pattern of expression.

To investigate the possibility of an association between the type of pathology caused by HTLV-I and the activity of its promoter, we compared the levels of transcription obtained with six LTRs isolated from patients with two different HTLV-I-related diseases: ATL and TSP/HAM. The patients came from different geographical endemic areas. The LTR region was amplified by polymerase chain reaction (PCR) from the DNA of uncultured peripheral blood lymphocytes, and directly cloned upstream of the luciferase reporter gene. Constructs were tested by a transient transfection assay in a variety of cell lines. Although the activities of these LTRs were statistically different in some of the cell lines tested, no correlation could be demonstrated between the promoter activity and the nature of the disease. Thus, the data suggest that the LTR is not a major determinant of the nature of the disease associated with the infection by HTLV-I.

Geographical subtypes demonstrated by RFLP following PCR in the LTR region of HTLV-I.

It has been demonstrated that specific mutations, localized in the long terminal repeat (LTR) region of HTLV-I, allowed to propose the existence of three HTLV-I subtypes. Because some of these mutations created or suppressed the restriction sites for ApaI, NdeI, DraI, SacI, MaeIII, and MaeII enzymes, these endonucleases were used for characterization of further 30 HTLV-I isolates. Seventeen proviral DNA from Japan, five from the Caribbean, one each from French Guyana, the United States, and China, two from Ivory Coast, and three from Zaire were tested. The DNA used were extracted from 26 in vivo peripheral blood mononuclear cell samples and from four cell lines obtained from two Japanese, one Chinese, and one North American patients. Digestions were performed on amplified DNA of the LTR region (nucleotides 31-768). The results confirm the existence of three subtypes of HTLV-I according to LTR sequences. Subtype I was observed only in patients from the Ivory Coast and Zaire. Subtype II was found in the patient from the French West Indies, and in 33% of the samples from Japan. Subtype III was most often observed in the Japanese but also in the Zairian patients.

Quantitation of HCV RNA using real-time PCR and fluorimetry.

Real-time PCR technology may provide an accurate and sensitive method to quantify hepatitis C virus (HCV) RNA. So far, studies have been carried out using the Taqman technology with the ABI Prism 7700 sequence detector. An alternative and simple real-time PCR assay is described with no probe requirement, based on the SYBR Green I dye and LightCycler fluorimeter. Amplicon synthesis was monitored continuously by SYBR Green I dye binding to double stranded DNA during PCR of the 5' HCV non-coding (NC) region. Specificity was verified by amplicon melting temperatures. An external standard curve was constructed with serial 10 fold dilutions of a modified synthetic HCV 5' NC RNA. A wide range linear relationship (up to 3.7x10(9) copies/ml) was observed between number of PCR cycle needed to detect a fluorescent signal and number of RNA copy. Intra- and inter-assay coefficients of variation were 0.7 to 2.1 and 3.7% respectively, indicating good reproducibility of the method. Thirty-three HCV positive sera of different genotypes were quantified by this method and gave similar but more sensitive results compared to the branched DNA (bDNA) technology.

Asthma self-management: the perspective of children.

This qualitative study explored the knowledge, perceptions, and autonomy of 7- and 12-year-old children relative to the management of their asthma. A total of 32 children with moderate to severe asthma were interviewed using an open-ended drawing interview and a semi-structured interview. The triangulation of results from these two methods revealed developmental differences. Younger children identified medicines by shape, color, or lay terms, relied on adults to manage their asthma, and did not recognize warning symptoms of an attack. Older children mastered biomedical terminology and used medicines independently, although they sometimes asked for the assistance of an adult. All children perceived benefits and non-monetary costs of asthma medicines. However, they lacked understanding of the categories and role of asthma medicines. This study suggests that long-term control and quick-relief metered dose inhalers should be identifiable by consistent color-coding, and that professionals should tailor asthma education and information to children's stages of cognitive development.

Does earlier headache response equate to earlier return to functioning in patients suffering from migraine?

This study explored the association between headache response and return to functioning, and identified migraine-associated symptoms related to functional status and acceptability of migraine treatment as reported by patients. Data from migraineurs enrolled in the active arms of a randomized, double-blind, parallel group, placebo-controlled, clinical trial were analysed. The relationships between headache response and functional response, and clinical factors and treatment acceptability were assessed using chi(2) tests of proportions and logistic regressions. A greater proportion of patients with headache response at 0.5 h were functioning at 0.5, 1 and 2 h compared with patients who did not attain a headache response at 0.5 h (P < 0.0001). These patients also were more likely to find their treatment acceptable (P < 0.05). The results suggest a direct temporal relationship among the key determinants of migraine resolution. Rapid headache response is associated with faster return to functioning; rapid headache and functional responses are significant attributes of treatment acceptability.

Physician over-the-counter drug prescribing patterns: an analysis of the National Ambulatory Medical Care Survey.

OBJECTIVE: To describe the prevalence of physician over-the-counter (OTC) drug prescribing in relation to selected physician, patient, and drug characteristics. DATA SOURCE AND METHODS: Data from the 1990 National Ambulatory Medical Care Survey, a multistage probability clustered sample, were analyzed. Physician drug utilization was expressed in drug mentions defined as "the physician's entry of a pharmaceutical agent ordered or provided, by any route of administration, for prevention, diagnosis, or treatment." Sampling weights were used to obtain unbiased national estimates. Cross tabulations of the drug prescription status (OTC or prescription [Rx]) with independent variables were performed, overall and by therapeutic class. The overall OTC/Rx ratio (0.11) was used as the cutoff point for distinguishing high- from low-level OTC drug prescribing. RESULTS: In 1990, 9.7% of physician drug mentions were of OTC drugs. Women between 16 and 34 years, Asian/Pacific Islanders, white Hispanics, and African-Americans experienced high OTC drug mentions (OTC/Rx > or = 0.11). After stratification by drug therapeutic class, physicians in general practice, family practice, internal medicine, obstetrics/gynecology, and pediatrics highly mentioned OTC drugs. CONCLUSIONS: OTC drug prescribing by physicians is substantial, and primary care specialties, patient gender, age, and race should be considered by those interested in evaluating OTC drug utilization in the ambulatory care setting.

Characterization of low- and very-low-density hepatitis C virus RNA-containing particles.

The presence of hepatitis C virus (HCV) RNA-containing particles in the low-density fractions of plasma has been associated with high infectivity. However, the nature of circulating HCV particles and their association with immunoglobulins or lipoproteins as well as the characterization of cell entry have all been subject to conflicting reports. For a better analysis of HCV RNA-containing particles, we quantified HCV RNA in the low-density fractions of plasma corresponding to the very-low-density lipoprotein (VLDL), intermediate-density lipoprotein, and low-density lipoprotein (LDL) fractions from untreated chronically HCV-infected patients. HCV RNA was always found in at least one of these fractions and represented 8 to 95% of the total plasma HCV RNA. Surprisingly, immunoglobulins G and M were also found in the low-density fractions and could be used to purify the HCV RNA-containing particles (lipo-viro-particles [LVP]). Purified LVP were rich in triglycerides; contained at least apolipoprotein B, HCV RNA, and core protein; and appeared as large spherical particles with a diameter of more than 100 nm and with internal structures. Delipidation of these particles resulted in capsid-like structures recognized by anti-HCV core protein antibody. Purified LVP efficiently bind and enter hepatocyte cell lines, while serum or whole-density fractions do not. Binding of these particles was competed out by VLDL and LDL from noninfected donors and was blocked by anti-apolipoprotein B and E antibodies, whereas upregulation of the LDL receptor increased their internalization. These results suggest that the infectivity of LVP is mediated by endogenous proteins rather than by viral components providing a mechanism of escape from the humoral immune response.

Molecular cloning and characterization of MSRV-related sequences associated with retrovirus-like particles.

New sequences have been obtained by successive overlapping RT-PCR extensions from the pol region of a retroviral RNA (multiple sclerosis-associated retroviral element, MSRV) amplified in retrovirus-like particles from patients with multiple sclerosis. gag and pol sequences are related to type C oncoviruses, whereas the env sequence is closer to type D. A tryptophan-like (W) tRNA primer-binding site was identified downstream of the RU5 region in the 5'LTR, and the U3R region cloned in the 3'LTR exhibited potent promoter activity. MSRV clones define a novel family of endogenous elements, HERV-W. From our data, HERV-W RNAs are copackaged in extracellular particles which might be produced by replication-competent or transcomplemented HERV-W copies or by an exogenous member of the HERV-W family.

Molecular identification of a novel retrovirus repeatedly isolated from patients with multiple sclerosis. The Collaborative Research Group on Multiple Sclerosis.

The partial molecular characterization of multiple sclerosis (MS)-associated retrovirus (MSRV), a novel retrovirus previously called LM7, is reported. MSRV has been isolated repeatedly from leptomeningeal, choroid plexus and from Epstein-Barr virus-immortalized B cells of MS patients. A strategy based on reverse transcriptase PCR with RNA-purified extracellular virions yielded an initial pol fragment from which other regions of the retroviral genome were subsequently obtained by sequence extension. MSRV-specific PCR primers amplified a pol region from RNA present at the peak of reverse transcriptase activity, coinciding with extracellular viral particles in sucrose density gradients. The same sequence was detected in noncellular RNA from MS patient plasma and in cerebrospinal fluid from untreated MS patients. MSRV is related to, but distinct from, the endogenous retroviral sequence ERV9. Whether MSRV represents an exogenous retrovirus with closely related endogenous elements or a replication-competent, virion-producing, endogenous provirus is as yet unknown. Further molecular epidemiological studies are required to determine precisely the apparent association of virions containing MSRV RNA with MS.