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Biomedical subjects

J Frey

Publications and source records attributed to J Frey.

338 records · Page 19Linked to original sources
PubMedDate not supplied

Detection of specific Mycoplasma conjunctivae antibodies in the sera of sheep with infectious keratoconjunctivitis.

The serological cross reactions between Mycoplasma conjunctivae, the etiological agent of infectious keratoconjunctivitis (IKC), and the antigenetically and phylogenetically closely related Mycoplasma ovipneumoniae, which is often found in sheep, were analysed. Cross reacting antigens were identified using sera from sheep with IKC and from sheep of herds known to be free of IKC, as well as rabbit hyperimmune serum specific to the two Mycoplasma species. Cross reactions were predominantly due to the strongly antigenic proteins of 42 kDa and 83 kDa. Serospecific antigens of M. conjunctivae could be separated from cross-reacting antigens by the extraction of Tween 20-soluble membrane proteins. The Tween 20-extracted proteins of the M. conjunctivae strain HRC/581T were used for the development of an indirect ELISA test. This ELISA test was shown to be a useful serological method for the diagnosis of M. conjunctivae infections and to identify infected sheep herds.

Animals↗
PubMedDate not supplied

Effects of D-penicillamine on collagen biosynthesis by fibroblast cell cultures.

The effects of D-penicillamine on collagen and total protein synthesis by fibroblast cell cultures were studied. High concentration of D-penicillamine (10 mmol/l) produced a toxic effect consisting of inhibition of growth and a non-specific increase in protein synthesis. A low concentration of D-penicillamine (100 mumol/l) decreased the biosynthesis of both type I and type III collagens.

Cell Division↗
PubMedDate not supplied

Nutritional markers, acute phase reactants and tissue inhibitor of matrix metalloproteinase 1 in elderly patients with pressure sores.

BACKGROUND: Loss of collagen and elastin is observed in the elderly. In geriatric inpatients, chronic protein malnutrition could induce susceptibility to additional morbidity such as pressure sores. OBJECTIVE: The purpose of this study was to explore the relationship between nutritional and inflammatory status and the production of tissue inhibitor of matrix metalloproteinase 1 (TIMP-1). METHODS: Chronically ill elderly inpatients, without or with pressure sores, were enrolled. Nutritional protein markers, acute phase reactants, and TIMP-1 were determined, and changes in these biological parameters were compared. RESULTS: Chronic inflammatory process and protein malnutrition were observed in all enrolled patients. The severity of these two pathophysiological processes was independent of the occurrence of pressure sores. The serum prealbumin and albumin levels were lower in patients with pressure sores than in those without. In addition, the general increase in the TIMP-1 level was independent of the occurrence of pressure sores. The TIMP-1 level was mainly related to the prognostic inflammatory and nutritional index. CONCLUSIONS: The general increase in acute-phase reactants observed in the elderly could be related to the intercurrent diseases. The generally low serum albumin level, lowest in patients with pressure sores, may be considered evidence of protein malnutrition and hypercatabolism. Regarding the morbidity, the increase in TIMP-1 levels could be explained as an adaptive process to prevent intrinsic protein expenditure of extracellular matrices.

Acute-Phase Proteins↗
PubMedDate not supplied

The reaction of aminoacylase with chloromethylketone analogs of amino acids.

1. Aminoacylase is irreversibly inactivated by the chloromethylketone analogs of benzyloxy-carobonyl-L-alanine, L-alanine, L-leucine, L-aspartic acid (beta), tosyl-L-phenylalanine and L-leucyl-L-alanine. The kinetics of the inactivation of the enzyme by the halo-methylketones were investigated. 2. Leucyl-and alanyl chloromethylketone inactivate the enzyme by blocking of 4 SH groups. Experiments with [U-14C]leucyl chloromethylketone confirm that maximal 4 residues are covalently bound to be protein. 3. Inactivation of the enzyme by benzyloxycarbonylalanyl and tosylphenylalanyl chloromethylketone is the result of the substitution of the epsilon-amino group of one lysine resine residue per active site and not of SH groups. However, in the presence of competitive inhibitors these halomethylketones react only with the SH groups of the enzyme, too.

Amidohydrolases↗
PubMedDate not supplied

[Clinical value of urinary biochemical parameters].

Twelve of the urine parameters, namely sodium, potassium, chloride, urea, creatinine, uric acid, calcium, phosphate, protein, microalbumin, amylase and glucose, routinely measured in a biochemistry laboratory were chosen to revalue their interest in clinical practice. For each parameter, urinary collection method, physiologic review and specific indications were set out. The clinical interest of chloride, urea, phosphate or uric acid measurement seem limited to specific pathological conditions. The measurement of urine amylase is out of interest.

Adolescent↗
PubMedDate not supplied

Search for mitochondrial A3243G tRNA(Leu) mutation in Polish patients with type 2 diabetes mellitus.

BACKGROUND: The influences of genetic and environmental factors form a clinical picture of type 2 diabetes mellitus. Genetic studies of type 2 diabetes mellitus become increasingly important. The knowledge of the molecular background of type 2 diabetes has been growing rapidly over recent years. One of the forms of the disease defined on the molecular level is maternally inherited type 2 diabetes mellitus. This diabetes, which is frequently accompanied by hearing impairment of deafness (maternally inherited diabetes with deafness-MIDD), was linked with sequence differences in mitochondrial DNA. The most frequent cause of MIDD is A3243G substitution in a mitochondrial tRNA(Leu) gene. While this mutation was identified in different races in several populations, it is still important and valuable to evaluate its prevalence in various ethnic groups. The aim of the project was to determine the prevalence of A3243G substitution in a mitochondrial tRNA(Leu) gene among Polish diabetic subjects. MATERIAL AND METHODS: In total 129 individuals, with type 2 diabetes and 12 with gestational diabetes were selected for this study. Two techniques based on restriction fragment length polymorphism (RFLP) method were used to screen for A3243G mutation. In the first approach, non-radioactive PCR reactions of mitochondrial DNA region of interest were performed using DNA of the study participants. This was followed by Apa I restriction enzyme digestion of the PCR product. Subsequently an electrophoretic separation was done on 2% agarose gel with ethidium bromide staining. In the second, more sensitive, modification of RFLP, [alpha 32P]dCTP was used for internal primer labeling and the electrophoresis was done on acrylamide gel. A positive sample was used to control the quality of the genotyping. RESULTS: In both approaches none of the samples, except for the positive control, showed the evidence of the G variant. CONCLUSIONS: In summary, the A3243G mutation in mitochondrial tRNA(Leu) gene is not a frequent cause of diabetes in the Polish population. Further screening of enlarging study group is necessary to fully determine the prevalence of this mutation in our population. This, together with the search for other mitochondrial mutations, should allow to fully determine the prevalence of MIDD and its specific molecular background in the Polish population.

Adult↗
PubMedDate not supplied

[Recommended algorithms of prescription in the diagnosis of iron deficiency and overload].

In view of the recent development of new tests of biochemistry and molecular biology the assessment of iron status should be reconsidered and updated. The French Society of Clinical Biology (SFBC) and the French Society of Hematology (Cellular Hematology Group) recommend algorithms in the diagnosis of iron deficiency and iron overload bearing in mind the best efficiency and health economy. These recommendations are based on the known sensibility and specificity of each test. The analytical requirements for the determination of the tests as well as the clinical and biological signs evoking an iron deficiency or overload are recalled.

Adult↗
PubMedDate not supplied

[Is there sugar in the Alzheimer's disease?].

Epidemiological and immunohistochemical studies focus the interest on the contribution of carbohydrates in the pathophysiology of Alzheimer's disease. Diabetes mellitus increases the risk. In the extracellular (senile) plaques, which contain aggregates of amyloid proteins, and in the neurofibrillary tangles within the cytoplasm of neurons, advanced glycation end products were detected. It is discussed whether it is a cause or an effect of the Alzheimer's disease. The vascular origin of the lesions is also considered.

Alzheimer Disease↗
PubMedDate not supplied

[Biochemical and pharmacological check-up in emergency orientation].

Biochemical and pharmacological tests usually prescribed in casualty department were reviewed taking into account their physiological significance and predictive value : ions, total proteins, carbohydrate and nitrogenous metabolites, enzymes, tissue markers, pharmacological drugs. Few blood components were kept with the first intention, ideally with a turn around time below one hour: sodium, potassium, chloride, bicarbonate, total proteins, pCO2 and pO2, creatinine, glucose, ketone compounds, calcium, bilirubin, transaminases, lipase, C-reactive protein, myoglobin, troponin, chorionic gonadotropin hormone. Those tests do not have to be systematically performed but prescribed only after the evaluation of pre-test probabilities by the clinician.

Biomarkers↗
PubMedDate not supplied

[Pheromones: an underestimated communication signal in humans].

The pheromones are molecules, mainly aliphatic acids, with or without perceptible odor, recognized by specific receptors, the stimulation of which induces neuroendocrine reactions and affects the individual behavior. Olfactory receptors are underexpressed in human, 70 % of genes have become nonfunctional pseudogenes. But the remaining function was tested and is able to induce emotional reactions corresponding to a non-verbal signal of social interactions. In the present study, we review the actual knowledge on the olfactory receptors. They belong to the G-protein-coupled-receptors. Their signal is transduced to the hypothalamic-pituitary-gonadal axis. Some HLA-based olfactory cues are shown with reference to recent experiments. The pathophysiological hypotheses are considered with respect to studies in anorexia nervosa and Alzheimer' disease.

Animals↗
PubMedDate not supplied

Regulation of CD3- lymphocyte function with an antibody against the IL-2 beta chain receptor: modulation of NK and LAK activity and production of IFN gamma.

To elucidate the role of interleukin 2 (IL-2) activation in CD3- lymphocytes, we examined the ability of monoclonal antibody (MAb) TU27, developed against the IL-2 receptor (IL-2R) p75 protein (IL-2R beta), to block lymphocyte activation with exogenous IL-2, as well as its innate ability to activate lymphocytes as a result of its surface ligand interaction. The binding of the TU27 MAb and the results of 125I-IL-2 cross-linking experiments suggest that the IL-2R beta chain is expressed primarily on CD3-, CD56+ lymphocytes; although the protein was also detected in a small portion of CD3+ cells, its expression appeared to be donor dependent. In the present study, we found that TU27 totally blocked natural killer (NK) cell activation in a 4-h assay but had no effect on basal levels of NK activity. When treatment was extended to 24 to 72 h, the MAb was able to block the induction of both NK and lymphokine-activated killer (LAK) activity. Of interest was the observation that MAb treatment alone augmented NK activity and subsequent interferon gamma (IFN gamma) production in CD3- lymphocytes but did not activate LAK activity or induce cell growth. Collectively, these results indicate that TU27 not only reacts with p70-75 IL-2R beta but can abrogate IL-2 binding and subsequent activation events. In addition, some CD3- lymphocyte functions (e.g., NK activity and IFN gamma secretion) are directly induced by the binding of MAb to p70-75 through signals that only partially mimic IL-2.

Antibodies, Monoclonal↗