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Biomedical subjects

M Schmid

Publications and source records attributed to M Schmid.

At least 613 records · Page 34Linked to original sources
PubMed1978

Analysis of banding patterns and mosaic configurations in a case of ring chromosome 15.

Cytogenetic studies on lymphocytes from a 14-year-old mentally retarded girl with somatic anomalies suggestive of a chromosomal abnormality revealed a ring chromosome 15. The long arm of the defective chromosome is broken at band q24 or q25. The silver staining technique for nucleolus organizer regions showed that the ring had lost the achromatic stalk and the satellite. The chromosomal mosaicism resulting from the structural instability of the ring chromosome was analyzed and compared with 6 cases reported in the literature. It is proposed that the clinical manifestations in the different patients with ring chromosome 15 result from both the deficiency in the long arm and the mosaic configurations.

Adolescent↗
PubMed1978

[Anti-HBc within the framework of hepatitis B virus infection: correlation to the form of inflammation and to the viral expression].

168 HBAg seropositive and 105 HBAg seronegative liver biopsies were studied for correlations between anti-HBc titers (indirect immunofluorescence method) and tissue expression of HBsAg and HBcAg (immunofluorescence), Dane particles in blood (immune electron microscopy) and inflammatory reaction. 98.8% of the HBAg seropositive patients were positive for anti-HBc. The mean titers showed statistically significant differences mainly between chronic aggressive hepatitis (1:2(11.3)) versus lobular hepatitis (1:2(10.1)), chronic persistent hepatitis (1:2(9.9)) and nonspecific reactive hepatitis (1:2(7.6)). Due to the considerable deviation of titers within the histological groups, however, titers below 1:2(11) are of low diagnostic relevance, whereas titers above 1:2(12) are mainly indicative of chronic aggressive hepatitis, although acute lobular hepatitis with signs of possible transition to chronicity or chronic persistent hepatitis with strong inflammatory activity may occur. Among HBAg seronegative patients 20% were positive for anti-HBc (mean titer = 1:2(7.7)). Among 78 patients also tested for anti-HBs, 10.2% were positive for both anti-HBc and anti-HBs. In an additional 12.8%, anti-HBc was the only marker of past hepatitis B virus infection. Anti-HBs was the only marker in a further 33%. In none of the HBAg seronegative patients and in only 59% of all HBAg seropositive patients, there was an association of anti-HBc with complete virus synthesis as measured by the demonstration of HBcAg in tissue or Dane particles in blood. It is concluded that anti-HBc is not a criterion of infectiosity but a specific, although non-characteristic, marker for HBAg seropositive acute and chronic hepatitis as well as for terminated HBV infection of all possible inflammatory and HBAg expression types.

Antibodies, Viral↗
PubMed1978

Cystic fibrosis and HLA.

In 94 children suffering from cystic fibrosis, no abnormal frequencies of HLA markers of the A and B locus were observed in comparison with the distribution of these antigens in control series. Furthermore, the HLA genotypes of seven pairs of diseased sibs are incompatible with the hypothesis of a closed linkage between CF--an autosomal recessive transmitted disease--and HLA.

Adolescent↗
PubMed1978

Comparative analysis of karyotypes in European shrew species. I. The sibling species Sorex araneus and S. gemellus: Q-bands, G-bands, and position of NORs.

The karyotypes of two closely related species of the genus Sorex (Mammalia, Insectivora) were compared with each other by G- and Q-banding techniques and by Ag-AS staining (GOODPASTURE and BLOOM, 1975). By comparing the G-banded karyotypes, it could be ascertained that the basic differences in karyotype between the two species lie in three pericentric inversions, three paracentric inversions, and one reciprocal translocation. This is in near agreement with FORD and HAMERTON (1970), who assumed that both species differ by three pericentric inversions and one tandem translocation. Furthermore, the karyotype of S. araneus (race C) presented by HALKKA et al. (1974) has been compared with the S. araneus of the present report. Considering the species with respect to karyotypic evolution, it is supposed that S. araneus and S. gemellus derive from a common ancestor.

Animals↗
PubMed1977

[Combined form of chronic aggressive hepatitis primary biliary cirrhosis].

15 patients with primary biliary cirrhosis (PBC) and 109 patients with chronic aggressive hepatitis (CAH) have been followed. Features of PBC, namely the generalized pruritus, massive rise in alkaline phosphatase, antimitochondrial antibodies and high levels of IgM-globulins, were present in 7 patients with CAH. This group was treated with immunosuppressive drugs for 1-2 years. Clinical, biochemical, immunological and histological parameters were used to assess the therapeutic effect. The pruritus improved and there was a statistically significant reduction in the IgG-hyperglobulinemia. Some resolution of the piecemeal necroses was seen. However, in judging these changes the sampling error must be taken into account. The unknown agent attacks both the hepatocytes and the epithelial cells of the bile ducts. The immunosuppressive treatment protects the liver cells from further damage while the progressive destruction of the bile ducts remains uninfluenced. The results suggest that the smallest possible dose sufficient to suppress the activity of CAH must be selected.

Alkaline Phosphatase↗
PubMed1977

[Immunological aspects of acute viral hepatitis treated with corticosteroids].

Acute viral B-hepatitis is the consequence of an effective specific immune response against the hepatitis B-virus with elimination of the virus. Corticosteroids decrease this immune reaction and thereby inhibit virus elimination. In principle, therefore, corticosteroid therapy promotes a transition to chronicity. This theoretical concept is documented practically by 8 patients treated with steroids in the early phase of acute viral hepatitis. Transition to some form of chronic liver disease is documented by serial liver biopsies in all 8 patients. The immunohistological findings showed the presence of HBsAg and HBcAg, as theoretically expected. These 8 selected cases, although uncontrolled, together with the theoretical concept of B-virus elimination, provide evidence against the use of corticosteroids in acute B-hepatitis.

Acute Disease↗
PubMed1977

Evidence for postmeiotic expression of ribosomal RNA genes during male gametogenesis.

Pre- and postmeiotic stages of male gametogenesis of 10 different vertebrate species belonging to mammals, birds, amphibians, and fishes were subjected to the Ag-AS staining technique (Goodpasture and Bloom, 1975). A uniform pattern of silver-staining is observable during spermatogenesis of the different vertebrate species. Silver-staining is present in spermatogonia and during the whole period of meiotic prophase, but totally absent during diakinesis and metaphase II of meiosis. In early spermatids silver-staining reappears and only disappears around the beginning of elongation of the spermatid nucleus. Since the Ag-AS technique is believed to stain only transcriptionally active nucleolus organizer regions, our findings indicate that ribosomal RNA genes become reactivated in the haploid spermatid.

Animals↗
PubMed1977

[HLA markers and periodic disease [familial Mediterranean fever (F.M.F.)] (author's transl)].

Thirty-one unrelated patients, 15-52 years old, were typed by microlymphocytotoxicity for 27 alleles of the HLA system. In addition, 12 families including 1 or more patient were also analysed. This criteria for diagnosis were those of Sohar et all. (Am. Intern. Med., 1967, 43, 227-253). All patients were of Israelite-Sephardin origin except two (Armenian and French); they were from North-Africa (Tunisia, Morocco and Algeria) and Israël. The results were compared to the antigen frequencies of 3 reference normal populations. The frequencies of the studied alleles do not differ from those of controls, except for HL-A28 and B14 slightly increased when compared to the normal frequencies. The study of 7 families with at least two sibs suffering from FMF shows a random distribution of the genotypes : 2 HLA identical, 6 different and 10 haploidentical diseased sibs. This distribution differs significantly (p less than 0.01) from that expected in the case of a recessive inheritance. These data do not support the hypothesis of a linkage between genes controlling FMF and HLA genes.

Adolescent↗
PubMed1977

Activation of mouse ribosomal RNA genes at the 2-cell stage.

The Ag-AS method, developed by Goodpasture and Bloom (1975) strains transcriptionally active nucleolus organizer regions (NORs) on the chromosomes and in the interphase nuclei. Metaphases and interphase nuclei of early mouse embryos (unfertilized eggs, pronucleus stages, 2-, 4-, 8-cell stages, and morulae) were subjected to silver-staining. First staining of a single chromosome bearing an NOR was observed at the 2-cell stage. At the 4-cell stage 4--6 chromosomes, and at the 8-cell stage invariably all the 6 chromosomes known to bear NORs, respond positively to silver-staining. These results indicate that during mouse embryogenesis ribosomal RNA genes start to function at the 2-cell stage. The polar body does not respond to silver-staining, which supports the view that the polar body genome remains inactive.

Animals↗
PubMed1977

Gene dosage effect for fumarate hydratase (FH; E.C. 4.2.1.2) in partial trisomy 1.

A strain of fibroblasts partially trisomic for the larger part of 1q (Norwood and Hoehn, 1974) contains about 1.5 times as much fumarate hydratase (FH) as various control-strains. This gene dosage effect was ascertained by (1) comparative measurements of the specific activity; (2) relating the specific activity of FH to that of reference enzymes, not influenced by the chromosomal anomaly; and (3) by immunoprecipitation methods, using a rabbit antiserum against pig heart FH which cross-reacts with the human enzyme. Among others, this gene dosage effect can be demonstrated numerically by the following parameters: Ratio of the average specific activity of FH in the trisomic strain to that of the control strains: 1.53. Corresponding ratio after dividing FH activity by that of reference enzymes; for acid phosphatase: 1.58, for glutamate dehydrogenase: 1.53. Average ratio of the immunoprecipitation areas obtained upon radial immunodiffusion according to Mancini et al. (1965): 1.56.

Acid Phosphatase↗