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Biomedical subjects

A Mathieu

Publications and source records attributed to A Mathieu.

At least 55 records · Page 3Linked to original sources
PubMed1993

Association of the HLA-A2, CW2, B27, S31, DR2 haplotype with ankylosing spondylitis. A possible role of non-B27 factors in the disease.

With the aim of searching for HLA haplotypes and non-B27 allele frequency variations in Sardinian AS patients, HLA-A, B, Cw, DR, DQ and Bf, C4A and C4B typing and haplotype assignment was carried out in the families of 25 AS patients and in 44 healthy individuals, all B27 heterozygotes. In the AS patients a significant increase of the A2, Cw2, B27, DR2, DQ1 haplotype was found. This depends only partially on the linkage disequilibrium existing in the Sardinian population between B27 and the other alleles of this haplotype, and rather seems to be due to a primary association of Cw2 and DR2 alleles with AS. Preliminary data seem to show that this haplotype bears the S31 complotype and the DRB1*1601 allele both in the AS patients and in the healthy controls. The pathogenetic implications of these findings are discussed.

Adult↗
PubMed1992

Circulating antibodies to DNA-related antigens in patients with autoimmune thyroid disorders.

A high prevalence of antibodies to double-stranded DNA (AbDNAds) has been recently reported in serum of patients with autoimmune thyroid disorders, but the specificity of this finding has been questioned. For this reason, the prevalence of several antibodies to DNA-related nuclear antigens (AbDRENA) has been evaluated in sera of patients with autoimmune and non-autoimmune thyroid disease. The study group included: 46 Graves' disease patients, 28 Hashimoto's thyroiditis patients, 25 patients with toxic nodular goitre and 11 with non-toxic nodular goitre. Twenty-eight Graves' patients were retested during methimazole (MMI) therapy, and 5 after radioiodine administration. Twenty-two patients with systemic lupus erythematosus and 28 normal subjects served as positive and negative controls, respectively. AbDRENA included: AbDNAds by RIA or immunofluorescence (IF); antibodies to single-stranded DNA (AbDNAss) and antibodies to histone (AbHist) by ELISA methods; antibodies to nuclear antigens (ANA) by immunofluorescence. RIA values were considered to be abnormal when 2 SD above the mean of normal controls. In our study 13% of Graves' patients were positive for AbDNAds by RIA: all of them had negative tests by IF; 11% were positive for AbDNAss, 2% for AbHist and 7% for ANA. A comparable prevalence of positive results for AbDNAds by RIA, with negative IF tests, was found in Hashimoto's thyroiditis patients. No significant changes of antibody levels were observed in Graves' patients during MMI treatment or after radioiodine administration. A positivity for AbDNAds or AbDNAss was found in 8% of patients with toxic nodular goitre, but in none of those with non-toxic goitre.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

A critical appraisal of the literature on the effects of computer-based clinical decision support systems on clinician performance and patient outcomes.

OBJECTIVE: To review the evaluations of computer-based clinical decision support systems (CDSS's). DATA SOURCES: The literature collected in the MEDLARS, EMBASE, SCISEARCH and INSPEC databases was searched from 1974 to the present. The reference lists of relevant articles were reviewed as were conference proceedings. STUDY SELECTION: Prospective, controlled studies were included. Studies were rated for methodological quality. DATA EXTRACTION: Study quality was assessed and data on study setting, subjects, method of allocation, and computer system were collected and verified using a structured form. CONCLUSIONS: There is considerable heterogeneity in both systems evaluated and design features of those systems. Future evaluations of CDSS's should focus on methodological issues in order to enhance overall quality of evaluations.

Clinical Medicine↗
PubMed1992

[The maxillofacial surgeon faced with the HIV-positive patient: risks and prevention].

Prevention against the transmission of the HIV must be universal today, which means that it applies to all patients. Blood, tissues, the CSF are infected, but nasal secreta, tears and saliva are not contaminated unless they contain blood. The statistical risk of an HIV serological conversion when making an injection is an estimate of 0.1 to 0.3%, one hundred times less than with the hepatitis B virus. The best protection for maxillofacial surgeons, who are very exposed by the manipulation of objects (needle, wires) and by considerable projections of blood (rotary motor) is not a systematic HIV serological test for all patients, but goggles with side screens, a double pair of gloves and the use of an antiseptic acting on the HIV in case of staining.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Seasonal and sex-linked variations in hepatic and extrahepatic biotransformation activities in striped mullet (Mullus barbatus).

Microsomal cytochrome P450 content, NADPH-cytochrome c reductase, and phase I (ethoxycoumarin and ethoxyresorufin O-dealkylases) and phase II (glutathione S-transferase and UDP-glucuronyltransferase) activities were studied in the liver and intestine of the striped mullet (Mullus barbatus) for 8 months (before and during sexual maturation). Biotransformation activities were much lower in extrahepatic tissues than the corresponding activities in the liver. Intestinal and hepatic biotransformation activities presented similar seasonal fluctuations: Phase I activity increased from October to February (during water cooling) and generally decreased before spawning; Phase II activity was not greatly different. Moreover, NADPH-cytochrome c reductase, ethoxyresorufin O-dealkylase, and glutathione S-transferase activities were measured in the kidney during the sexual maturation period. Renal phase I and phase II activities showed very little fluctuation during the 5 months studied. Cytochrome P450 and ethoxycoumarin and ethoxyresorufin O-dealkylases exhibited sex-linked differences during sexual maturation, whatever the tissue: in the liver the values are higher in male fish, whereas in the intestine and kidney they are lower.

Animals↗
PubMed1991

Mixed-function oxygenase enzymes as tools for pollution monitoring: field studies on the French coast of the Mediterranean Sea.

1. MFO enzyme activities were measured in microsomes from whole mussels (Mytilus galloprovincialis) comber livers (Serranus cabrilla), or Posidonia oceanica etiolated tissues, and PAH contents were determined in sediments collected in coastal locations of the French Riviera and Corsica during 3 oceanographic cruises in 1987-1988. 2. BaP activities in mussel and EROD activities measured in fish were strongly correlated to the log of PAH content in sediments. The first results for CA4H in Posidonia showed significant differences related to PAH pollution levels. The increase in MFO activities measured in Corsica in summer 1988 indicated a recent petroleum contamination.

Animals↗
PubMed1991

PREOP: development of an evidence-based expert system to assist with preoperative assessments.

PREOP is a prototype expert system that is designed to provide physicians with evidence-based recommendations concerning the assessment and care of patients with comorbid medical problems who are about to undergo surgery. The knowledgebase for this system is currently undergoing transition from the conventional advice of medical experts, which is variably related to evidence published in the medical literature, to a more formal approach in which the best available evidence is used for each recommendation and the quality of the evidence made apparent to the user. This work seeks to address important questions concerning improvement of the information contained in expert knowledgebases, namely, how to find and recognize new evidence when it is published, how to assess the quality of evidence in a uniform and efficient fashion, how to replace evidence in the knowledgebase efficiently when it has been superseded by higher quality evidence, and how to represent evidence in a manner that is most valuable for the user.

Decision Making, Computer-Assisted↗
PubMed1991

[Concentration of selenium in nutrition and blood serum of diabetic children and adolescents].

During 6 days the food of 7 patients of an instruction center for juvenile diabetics contained 60.94 +/- 2.87 micrograms selenium/day. Thereafter the serum selenium concentration was 91.24 +/- 8.57 ng/ml. The corresponding figures for 9 controls of the same age (pupils of a boarding school) were 35.90 +/- 12.24 micrograms selenium/day and 60.94 +/- 10.07 ng/ml, respectively. The differences are the result of the diabetic diet containing more proteins rich in selenium than the food of the controls.

Adolescent↗
PubMed1990

The uptake metabolism and biological half-life of benzo[a]pyrene in different tissues of sea bass, Dicentrarchus labrax.

The disposition of polycyclic aromatic hydrocarbons in aquatic organisms is of interest from the viewpoint of both animal and human health. The kinetics of uptake and metabolism of benzo[a]pyrene (BaP) were studied in various tissues of the marine fish, sea bass, upon intraperitoneal injection of the compound. A decrease in radioactivity occurred in all tissues and the calculated half-lives were 12.4 days for fat, 6.5 for kidney, 5.1 for intestine, 4.8 for gallbladder, 4.5 for spleen, 2.9 for muscle, 2.4 for whole body, 2.3 for gonads, 2.3 for gills, and 2.2 for liver. The kinetics of distribution of radioactivity between alkali and hexane tissue extracts were determined in order to assess the overall metabolic potential of various organs. The liver, intestine, gills, and kidney displayed a relatively high metabolic potential in comparison with the spleen, muscle, gonads, and fat. The significance of the observations with respect to understanding mechanisms of toxicity is briefly discussed. Attention is specifically drawn to the presence of a fairly active metabolism or metabolite redistribution system in the muscle and the potential for exposure of blood cells to metabolites via hydrocarbon transformation processes in the spleen. This in vivo study, in which hydrocarbon disposition was studied in various tissues, also supports the hypothesis that polycyclic aromatic hydrocarbons should not bioaccumulate to any significant degree in fish and that exposure of humans to such compounds through the consumption of fish products can be expected to be minimal.

Animals↗
PubMed1990

Maturation of the hypothalamic control of pulsatile gonadotropin-releasing hormone secretion at onset of puberty. I. Increased activation of N-methyl-D-aspartate receptors.

In the male rat the timing of puberty can be estimated by the rapid increase in testicular weight occurring between 25-50 days of age. We found that elongated spermatids, the most mature germ cells identified using flow cytometry, were first seen at 25 days (4% of the testicular cells), while an adult proportion (63%) was attained by 45 days of age. We have shown previously that hypothalamic explants could release GnRH in a pulsatile fashion at a frequency increasing around the age of 25 days, thus consistent with the time of onset of puberty. Since pulsatile GnRH secretion could be suppressed by MK-801, a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) receptor activation, we postulated that an increased activation of those receptors could be involved in the neuroendocrine mechanism that activates pulsatile GnRH secretion at the onset of puberty. Such a concept was supported by the NMDA-induced release of GnRH, which was observed using 1 mM NMDA at 25 days, while a dose of 20-50 mM was required at 15 or 50 days of age. MK-801 could provide an index of NMDA receptor activation, since the antagonistic effect of MK-801 is use dependent. This particular property was confirmed by the inability of MK-801 (5 pM) to block the depolarization (veratridine)-induced release of GnRH in the presence of 0.001 mM NMDA, while partial or complete suppression was obtained in the presence of 0.1 and 10 mM NMDA, respectively. Using explants obtained at 5, 10, 15, 20, 25, 30, 35, and 50 days of age, the lowest concentrations of MK-801 that blocked the veratridine-induced release of GnRH were, respectively, 10(7), 10(7), 10(7), 10(3), 10, 10(2), 10(4), and 10(8) pM. In contrast, there was no age-related difference in sensitivity to the inhibitory effect of Mg2+, a noncompetitive NMDA receptor antagonist which is not use dependent. The pulsatile secretion of GnRH occurred at a similar frequency at 25 and 50 days of age (4.7 and 5.4 pulses/3.5 h, respectively) but it was suppressed by a lower MK-801 concentration at 25 days (10(4) pM) than at 50 days (10(8) pM). These data indicate that the NMDA receptors involved in the control of pulsatile GnRH secretion are markedly and transiently activated around the time of onset of puberty in the male rat.

Aging↗
PubMed1988

The efficacy and safety of auranofin in the treatment of juvenile rheumatoid arthritis. A long-term open study.

The safety and efficacy of auranofin in the long-term treatment of children with juvenile rheumatoid arthritis was investigated in an open study of 14 patients. Twelve patients completed at least 12 months of treatment, and 7 patients completed 36 months of treatment. Classic parameters of disease activity showed improvement over baseline values after 6 months of treatment, and laboratory indices remained stable or improved throughout the study. Auranofin was well tolerated; the frequency of adverse effects was lower in these patients than has been previously reported in either adults or children whose arthritis has been treated with injectable gold.

Adolescent↗