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Biomedical subjects

M Simon

Publications and source records attributed to M Simon.

At least 559 records · Page 31Linked to original sources
PubMed1983

Lymphocytotoxicity for oral mucosa in lichen planus.

The in vitro effect of peripheral blood lymphocytes on syngeneic oral epithelial cells was investigated in 23 patients suffering from lichen planus of skin and/or mucous membranes and in 18 healthy sex- and age-matched volunteers as controls. A modified 51Cr release macro-assay was used. The result shows a significant lymphocytotoxic effect on the epithelial target cells, giving evidence of cytolytic activities of blood lymphocytes on autologous epithelial cells. We consider these lymphocytes to be involved in the complex pathogenesis of lichen planus.

Adult↗
PubMed1983

[Not Available].

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History of Pharmacy↗
PubMed1983

The diagnostic value of varicella-zoster virus (VZV)-specific antibodies in the early phase of varicella in immunocompromized children.

Varicella-zoster virus (VZV)-specific antibodies were tested by indirect membrane immunofluorescent technique in sera of 32 immunocompromized children during the first week after onset of varicella. VZV-specific IgM antibodies were found in sera of all but four patients. Three of the four IgM negative patients were followed up, and it was demonstrated that all of them gave a retarded antibody response. They had severe leukopenia and had several relapses of their VZV-infection. The results indicate (a) that the demonstration of VZV-specific IgM antibodies is of diagnostic value even in atypical varicella of immunocompromized patients; and (b) that in cases with retarded antibody response relapses can be expected.

Adolescent↗
PubMed1982

Bacterial bioluminescence: isolation and expression of the luciferase genes from Vibrio harveyi.

Genes for the luciferase enzyme of Vibrio harveyi were isolated in Escherichia coli by a general method in which nonluminous, transposon insertion mutants were used. Conditions necessary for light production in E. coli were examined. Stimulation of transcription of the genes for luciferase (lux A and lux B) was required for efficient synethesis of luciferase. To enhance transcription bacteriophage promoter elements were coupled to the cloned lux gene fragments.

Escherichia coli↗
PubMed1982

Determination of niacin metabolites 1-methyl-5-carboxylamide-2-pyridone and N-1-methylnicotinamide in urine by high-performance liquid chromatography.

A test suitable for detecting latent niacin deficiency was developed. It measures the 24-h urinary output of the two major metabolites of niacin, 1-methyl-5-carboxylamide-2-pyridone and N-1-methylnicotinamide. The two metabolites were isolated from urine using separate ion-exchange extractions. They and their two internal standards were quantitated simultaneously by high-performance liquid chromatography using a reversed-phase ion pairing separation. Detection was by absorbance at 254 nm.

Chromatography, High Pressure Liquid↗
PubMed1982

Epstein-Barr virus induction by a serum factor. Purification of a high molecular weight protein that is responsible for induction.

Serum contains a factor that induces Epstein-Barr virus antigens in latently infected human lymphoblastoid cell lines and that cooperates with chemical inducers. Here we report the purification of a protein that is responsible for the effect. Using ammonium sulphate precipitation, chromatography on DEAE-agarose and cellulose, molecular sieve chromatography on Bio-Gel A-5, and glycerol gradient centrifugation, the factor was enriched about 300,000-fold compared to calf serum. Under neutral conditions, the protein chromatographed as a high molecular weight protein of about 5.5 X 10(5) both in its active and inactive form. Both forms of the molecule sedimented at about 7 s. The factor is an acidic protein with a pI of 5. It seems to be composed of high molecular and low molecular weight subunits. Nanogram amounts of purified factor are sufficient for measurable inducing effects.

Animals↗
PubMed1982

Epstein-Barr virus induction by a serum factor. Characterization of the purified factor and the mechanism of its activation.

Purified Epstein-Barr virus-inducing factor shows all the properties previously described for crude serum, i.e. inducing activity, cooperative activity with the inducers 12-O-tetradecanoyl-phorbol-13-acetate, 5'-iodo-2'-deoxyuridine, N-butyric acid, anti-IgM, and the need to be activated by pH shock. A small subpopulation of untreated factor molecules is fully active, however. The factor is a protein that is characterized by considerable heat resistance and sensitivity to reducing agents. It does not seem to require sugar residues or lipid for its activity. Activation occurs both at alkaline and acidic pH. Inactive and activated factor differ in their sensitivity to trypsin and in the degree of sensitivity to reducing agents. A change of conformation within the molecule seems to be the biochemical basis for the activation reaction.

Animals↗
PubMed1982

Determination of the anticoagulant phenprocoumon in human plasma and urine by high-performance liquid chromatography.

The determination of the anticoagulant phenprocoumon in plasma, after acidification and extraction with 1,2-dichloroethane was effected through isocratic high-performance liquid chromatography; a C18 reversed-phase column was used as stationary phase using aqueous acetonitrile as eluent and UV detection at 313 nm; p-chlorophenprocoumon was used as internal standard. A high proportion of phenprocoumon in urine is eliminated as the glucuronide and must be hydrolyzed enzymatically before extraction; the same column and detector as for plasma were used, but with gradient elution. The method was used in the range 0.1-5 mg/1, the sensitivity was 0.1 mg/1 for plasma and 0.02 mg/1 for urine, the precision was in the range 3-5% and the absence of interference due to other anticoagulants, drugs or endogenous compounds allows the specific determination of phenprocoumon in plasma and urine from patients and volunteers in clinical relevant cases, drug interaction, compliance, toxicological and pharmacokinetic studies.

4-Hydroxycoumarins↗
PubMed1982

Effects of olivacine on the metabolism of proteins and nucleic acids in Escherichia coli.

Olivacine, a semi-synthetic isomer of ellipticine, interferes with the growth of Escherichia coli. Investigation of the effects of graded concentration shows that, in vivo, the synthesis of overall proteins is markedly more sensitive to low concentrations than is the synthesis of RNA and DNA, respectively. Furthermore, at moderate concentrations, olivacine is much more inhibitory to the synthesis of cytoplasmic proteins than to that of envelope proteins. At lethal concentration (10-4 M) all macromolecular syntheses are inhibited, DNA synthesis, however, to a lower extent. Olivacine blocks the synthesis of polyribonucleotide and polypeptide chains at the elongation step. The resulting nascent products of both transcription and translation are unstable, whereas completed RNA molecules are partially stabilized in the presence of the drug.

Antineoplastic Agents, Phytogenic↗
PubMed1982

[Immunological investigations in recurrent herpes simplex (author's transl)].

Various immunological parameters were studied in 49 patients suffering from recurrent herpes simplex and in 100 healthy sex- and age-matched individuals. The study included determination of immunoglobulins in serum, classification and PHA-stimulation of peripheral lymphocytes as well as testing different granulocyte functions in vitro. We found a moderately reduced number of T-lymphocytes in 20 patients and a strikingly decreased rate of PHA-induced lymphocyte transformation in 30 patients. A slight impairment of chemotactic activity and markedly reduced capacity of killing Candida albicans blastospores by granulocytes was also found. These results point to an immunological alteration in patients with recurrent herpes simplex.

Adult↗
PubMed1982

[Professional future after myocardial infarction (author's transl)].

After a first myocardial infarction, the professional future of 86 patients is studied. 80 men and 6 women are included in the study. The mean age is 50.68 years. Manual workers prevail among affected patients, regardless of their age or of the site of the infarct. 78% of patients under 60 years resumed work, during the first threa months in more than half the cases, without any readjustments. The mean age of patients who resumed work is 47.6 years. Work was more often completely discontinued among office clerks and business managers than among other professions. Difficulties in finding readjusted jobs are greater for manual workers, especially if they belong to a small firm or if they are over 50. From a psychological and professional point of view, rehabilitation should be included in the management of myocardial infarction, even if it's impact on long-term mortality remains unknown.

Adult↗