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Biomedical subjects

A Mosser

Publications and source records attributed to A Mosser.

12 recordsLinked to original sources

The 16189 variant of mitochondrial DNA occurs more frequently in C282Y homozygotes with haemochromatosis than those without iron loading.

BACKGROUND: Patients with hereditary haemochromatosis (HH) are usually homozygous for the C282Y mutation in the HFE gene. They have variable expression of iron overload and present with a variety of complications, including liver disease, diabetes, arthropathy, fatigue, and cardiomyopathy. The mitochondrial 16189 variant is associated with diabetes, dilated cardiomyopathy, and low body fat at birth, and might contribute to genetic predisposition in further multifactorial disorders. The objective of this study was to determine the frequency of the 16189 variant in a range of patients with haemochromatosis, who had mutations in the HFE gene. METHODS: Blood DNA was analysed for the presence of the 16189 variant in British, French, and Australian C282Y homozygotes and controls, with known iron status, and in birth cohorts. RESULTS: The frequency of the mitochondrial 16189 variant was found to be elevated in individuals with haemochromatosis who were homozygous for the C282Y allele, compared with population controls and with C282Y homozygotes who were asymptomatic (42/292 (14.4%); 102/1186 (8.6%) (p = 0.003); and 2/64 (3.1%) (p = 0.023), respectively). CONCLUSIONS: Iron loading in C282Y homozygotes with HH was exacerbated by the presence of the mitochondrial 16189 variant.

Adult↗

10-year educational programme aimed at rheumatic fever in two French Caribbean islands.

BACKGROUND: In less developed countries, rheumatic fever still occurs. We started a long-term educational programme in two French Caribbean islands that was directed at the public and at health-care workers to see whether we could reduce the incidence of rheumatic fever. METHODS: Our 10-year programme started in 1981 in Martinique and Guadeloupe, and was based in the community and in clinics and hospitals. The programme established a registry of all cases of primary and secondary rheumatic fever (diagnosed by Jones' modified criteria), with systematic hospital admission of children. We graded carditis as severe, mild, or subclinical, and acute glomerulonephritis was defined by oedema, proteinuria, and haematuria for less than 3 months. The educational part of the programme targeted the public and health-care workers, including doctors, with written information distributed in schools or via radio and television broadcasts or videotapes. For the public, the benign clinical presentation of the initial streptococcal infection was contrasted with the severity of later heart disease. FINDINGS: The first months of the programme led to a 10-20% increase in the number of rheumatic fever cases admitted to hospital, because of the renewed attention paid to the disease. Therefore we took 1982 as the baseline year. In 1982-83 the incidence of rheumatic fever was 19.6 per 100 000 inhabitants aged under 20 in Martinique, and 17.4 per 100 000 in Guadeloupe. In 100 Martinique children and 97 Guadeloupe children in 1982-83, 40 and 71% had carditis, respectively (severe in 10 and 32%). Rheumatic fever was preceded by symptomatic sore throat in 52 and 41% of cases, respectively. The disease was not seen in children with active streptococcal cutaneous infections. Disease frequency was highest in the poorest areas and families, a finding that persisted over time. The programme was associated with a progressive decline in the frequency of rheumatic fever: final reduction of 78% in Martinique and 74% in Guadeloupe. The frequency of carditis also fell. Apart from two outbreaks in one hospital, the frequency of acute glomerulonephritis also declined; 31% of cases had had sore throat, while 56% had skin infections. The cost of the programme during the 4 most intensive years was FFr 250 000 (US$ 44 500) in each island. The cost of childhood rheumatic fever, excluding late sequelae, was initially (in 1982) about FFr 7.8 million (US$ 1426 000). The cost fell to an average of Ffr 550 000 (US$ 100 000) per year in 1991-92. INTERPRETATION: A rapid decline in rheumatic fever incidence was achieved at modest cost. Such a programme needs to be continued because of the risk of disease resurgence.

Adolescent↗

Postabsorption neutralization of poliovirus.

Nineteen neutralizing murine monoclonal antibodies against poliovirus type 1, including representatives reacting with each of the antigenic sites on the virion, were tested for their abilities to neutralize the virus either before or after attachment to susceptible cells. All antibodies neutralized unattached virus; six had reasonable titers of postabsorption neutralization (PAN). Experiments with antibodies lacking PAN activity showed that Fc-specific rabbit anti-mouse antibodies could confer PAN activity. PAN was shown to involve the prevention of the cell-mediated conversion of virus to 135S and 80S particles. Evidence that one of the PAN-positive antibodies probably bound bivalently to preabsorbed virions, whereas a PAN-negative antibody bound monovalently, is presented. Two PAN-positive antibodies were added to an excess of virus in suspension, and only one antibody caused the virus to aggregate.

Antibodies, Monoclonal↗

Creation of an antigenic site in poliovirus type 1 by assembly of 14 S subunits.

Using a set of neutralizing monoclonal antibodies targeted against the four known antigenic sites of poliovirus type 1, it was shown that three out of four antigenic sites are already present on 14 S subunits (pentamers of the structural unit). Site 3B, in contrast, is formed upon assembly of 14 S subunits into capsids. The data support the hypothesis that site 3B spans the boundary between pentamers in the virion.

Antibodies, Monoclonal↗

Surface physics methods and in vitro bone-biomaterial interface control.

After a brief review of the main characteristics of some spectroscopic and microscopic methods for surface and interface analysis, preliminary and prospective studies of biocompatible materials (hydroxyapatite, alumina) for implant coating purposes are presented. The results show that the use of complementary techniques allows information on the physical and chemical properties of the coatings both on a microscopic and on an atomic scale to be obtained.

Aluminum Oxide↗

Biological control of Biomphalaria glabrata and B. straminea by the competitor snail Thiara tuberculata in a transmission site of schistosomiasis in Martinique, French West Indies.

In Martinique, intestinal schistosomiasis was discovered at the beginning of this century. The intermediate host snail, Biomphalaria glabrata, was considered in the past as a common species in the different habitats of the island, but during the last decade it has been found only in water-cress beds. Several of these water-cress cultures contained mixed populations of B. glabrata and B. straminea. Moreover, these habitats also constituted transmission sites for Schistosoma mansoni infection. In 1979 the thiarid snail Thiara ( = Melanoides) tuberculata was discovered in Madame river, Fort-de-France, and in the following years at other sites. In 1983 a programme of biological control using this snail was started in two groups of water-cress beds. In 1981-1982 the study site, Roxelane valley, sheltered important populations of B. glabrata (45-256 individuals/m2) and of B. straminea (2-30 ind./m2). In January 1983 the competitor T. tuberculata was introduced into the two groups of water-cress beds (1.3 and 1.7 ind./m2 respectively) and during subsequent years snail population sampling was carried out. The results showed rapid colonization by the competitor snail, whose densities reached 178 and 325 ind./m2 in November 1983 and a maximum of 9941 and 13,388 ind./m2 in October 1984. During that time, B. glabrata populations declined: 153 and 41 ind./m2 in November 1983, 4 and 0 ind./m2 in October 1984, and 0 ind./m2 in the two groups of water-cress beds in October 1985. A similar phenomenon was observed for B. straminea. Since October 1985 neither planorbid species has been found by exhaustive sampling of the habitats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Acute rheumatic fever in Martinique. Epidemiological, clinical and biological study].

An epidemiological and clinical survey of rheumatic fever was carried out in Martinique. The clinical manifestations, portal of entry and socio-economic facilitating factors appeared to be the same as those observed in metropolitan France when the disease occurred with a similar frequency. The prevalence and severity of rheumatic fever in Martinique are still high (in 1982, 49 new cases in a population of 300,000, including 12 with severe carditis), but they tend to diminish as the eradication campaign goes on. The reasons for the persistence of the disease and the problems encountered in the eradication campaign are discussed in the light of epidemiological data collected during the last 3 years.

Adolescent↗

[The psychosomatic approach in general medicine].

When the general practitioner is convinced that a somatic symptom covers a psychosomatic problem, he may choose one of two strategies. The first is to minimize it on the grounds of possible subsequent change or to spare a vital compromise (duty of reservation). The second is to ignore the request in order to offer the possibility of implementing his therapeutic conviction. In this strategic choice, the doctor's authority as a "trustee" is pitted, in practice, against the inconsistent and irresolute nature of the request, and the shortcomings of the institution or socioeconomic level. Strangely enough, psychologising information may jeopardize the therapeutic commitment. The higher the cultural level, the greater the deviation, especially in depression. Observations from everyday practice in urban centers exemplify the variety of these approaches.

Adolescent↗

[Contraceptive hormones, vascular risk and abnormal precipitation of serum gamma-globulins (author's transl)].

The monoclonal anti-ethinyl-estradiol antibody previously found in the serum of a woman on oral contraceptives, was precipitated by 25% saturated ammonium sulfate à 22 degrees C. This simple test has been used to investigate the possible relationship between abnormally precipitating gamma-globulins (GAP) and the vascular risk of the pill. Four groups of women were studied: --50 women who had never used the pill; --100 women on oral contraceptives; --30 women who had stopped the pill; --17 women had experienced venous or arterial thrombosis during oral contraception. The results obtained indicate: 1) that a GAP increase is nearly always associated with the thrombotic events (90% of the cases in group 4); 2) that the presence of GAP is seen only in part of the women population on oral contraceptives representing approximately 30% of the total population investigated as indicated by a bimodal distribution. 3) that the GAP remain increased for months and even years after the pill was discontineud. The significance of this test is discussed. It is proposed that the presence of GAP in the serum appears to be related to the presence of ethinyl-estradiol binding antibodies. This hypothesis is verified by experiments in progress.

Adolescent↗

[Contraceptive hormones, vascular risk and abnormal precipitation of serum gamma-globulins (author's transl)].

The monoclonal anti-ethinyl-estradiol antibody previously found in the serum of a woman on oral contraceptives, was precipitated by 25% saturated ammonium sulfate à 22 degrees C. This simple test has been used to investigate the possible relationship between abnormally precipitating gamma-globulins (GAP) and the vascular risk of the pill. Four groups of women were studied: --50 women who had never used the pill; --100 women on oral contraceptives; --30 women who had stopped the pill; --17 women who had experienced venous or arterial thrombosis during oral contraception. The results obtained indicate: 1) that a GAP increase is nearly always associated with the thrombotic events (90% of the cases in group 4); 2) that the presence of GAP is seen only in part of the women population on oral contraceptives representing approximately 30% of the total population investigated as indicated by a bimodal distribution; 3) that the GAP remain increased for months and even years after the pill was discontinued. The significance of this test is discussed. It is proposed that the presence of GAP in the serum appears to be related to the presence of ethinyl-estradiol binding antibodies. This hypothesis is verified by experiments in progress.

Adolescent↗