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Biomedical subjects

M Schmid

Publications and source records attributed to M Schmid.

At least 523 records · Page 29Linked to original sources
PubMed1983

[Hepatitis B virus infection and hepatocellular carcinoma: indication for a possible causal connection even in non-endemic Switzerland].

62 patients with histologically proven hepatocellular carcinoma have been investigated for the presence of serological markers of hepatitis B virus infection, and the findings have been related to alpha 1-fetoprotein measurements and to the nature of the basic disease process affecting the liver. The results document a statistically significant increase in the prevalence of hepatitis B virus markers as compared to patients with cirrhosis of the liver only, pointing to a probable etiological relationship between hepatitis B virus infection and hepatocellular carcinoma even in areas of the world where the infection is not endemic. Early detection of hepatocellular carcinoma is limited by the remarkably high percentage of patients who have no, or only marginal, elevation of serum alpha 1-fetoprotein.

Adult↗
PubMed1983

[Long-term course of sporadic non-A, non-B hepatitis: a biochemical, immunologic and histologic follow-up study].

36 patients with acute sporadic non-A, non-B viral hepatitis were prospectively followed up. Study parameters included biochemical and immunological (hepatitis A/B) data, histology of the acute and chronic stage of the disease and immunohistology for hepatitis B markers. The mean follow-up period for the patients with complete remission was 8.5 months, and 30.5 months for the patients with progression to chronic liver disease. 13 (36%) patients developed histologically confirmed chronic hepatitis (6 CPH, 7 CAH). In the chronic stage of the disease, the transaminases showed a markedly fluctuating course in 8 of the 13 patients. Two of the 6 patients with CPH showed complete remission after 25 and 58 months respectively; in the 4 others the disease remained unchanged. In the 7 patients with CAH no remission occurred, but in 2 patients complete cirrhotic transformation of the liver was demonstrated after 36 and 38 months respectively. Hence the prognosis of chronic sporadic non-A, non-B hepatitis seems to be worse than the prognosis of chronic posttransfusion non-A, non-B hepatitis.

Adolescent↗
PubMed1983

Use of isosorbide dinitrate saliva concentrations for biopharmaceutical investigations.

The concentration of isosorbide dinitrate in paired samples of plasma and mixed saliva was monitored for up to 24 hr after oral administration of 60 mg of sustained-release isosorbide dinitrate to eight healthy volunteers. Measured isosorbide dinitrate plasma concentrations were mainly in the range of 0.1-10 ng/ml. Isosorbide dinitrate was excreted into saliva resulting in a mean (+/- SD) saliva-plasma concentration ratio of 0.68 +/- 0.37. A significant correlation between concentrations of isosorbide dinitrate in saliva and plasma was found (p less than 0.01). The sustained-release properties of the administered formulation were confirmed from the concentrations of isosorbide dinitrate found in both saliva and plasma. Saliva-plasma ratios were independent of the absolute concentrations of isosorbide dinitrate but showed a slight tendency to decrease with time. The principal factor relating saliva and plasma isosorbide dinitrate concentrations appeared to be the degree of plasma protein binding of the drug.

Adolescent↗
PubMed1983

Silver staining of nucleolus organizer regions during human spermatogenesis.

The sizes and staining intensities of the nucleolus organizer regions (NORs) in human spermatogenesis were studied qualitatively and quantitatively with the silver (Ag)-staining technique. The Ag-stainability of the NORs is a measure of the transcriptional activity of the ribosomal RNA genes. Ag-stained NORs are present during the whole period of meiotic prophase up to pachytene and totally absent in the two meiotic metaphases. In the early spermatids the Ag-stainability of the NORs reappears and persists up to the beginning of the elongation phase of the nuclei. This pattern of NOR-activity during spermatogenesis is common for all vertebrates. However, in human spermatogenesis the absolute sizes of the NORs in the pre- and postmeiotic stages as well as the interphase arrangement of the postmeiotically reactivated NORs show characteristic properties not found in any other species. The cytochemistry of the argentophilic material, the significance of the synthesis of ribosomal RNA in spermatogenesis, and the characteristic arrangement of the Ag-stained NORs in the spermatids are discussed.

Animals↗
PubMed1983

Chromosome banding in Amphibia. VIII. An unusual XY/XX-sex chromosome system in Gastrotheca riobambae (Anura, Hylidae).

The mitotic and meiotic chromosomes of the marsupial frog Gastrotheca riobambae were analysed with various banding techniques. The karyotype of this species is distinguished by considerable amounts of constitutive heterochromatin and unusual, heteromorphic XY sex chromosomes. The Y chromosome is considerably larger than the X chromosome and almost completely heterochromatic. The analysis of the banding patterns obtained with GC- and AT-base-pair-specific fluorochromes shows that the constitutive heterochromatin in the Y chromosome consists of at least three different structural categories. The only nucleolus organizer region (NOR) of the karyotype is localized in the short arm of the X chromosome. This causes a sex-specific difference in the number of NOR: female animals have two NORs in diploid cells, male animals one. No cytological indications were found for the inactivation of one of the two X chromosomes in the female cells. In male meiosis, the heteromorphic sex chromosomes form a characteristic sex-bivalent by pairing their telomeres in an end-to-end arrangement. The significance of the XY/XX sex chromosomes of G. riobambae for the study of X-linked genes in Amphibia, the evolution of sex chromosomes and their specific DNA sequences, and the significance of the meiotic process of sex chromosomes are discussed.

Animals↗
PubMed1983

Immunogenicity of a hepatitis B subunit vaccine in hemodialysis and in renal transplant recipients.

A hepatitis B subunit vaccine was given to 59 medical staff members, 106 hemodialysis patients and 28 renal allograft recipients. The vaccine consisted of formalin-inactivated hepatitis Bsurface antigen (HBsAg) and was given in 3 doses (times 0, 1 and 6 months) of 20-40 micrograms. Some of the vaccinees received anti-HBs antibodies together with the first vaccine dose (active/passive vaccination). One month after the last infection, 93% of the medical staff members who had received active/passive immunisation and 97% of those who had received active immunisation had detectable anti-HBs antibodies with mean titers ranging from 1:512 to 1:1024. In the group of hemodialysis patients antibodies were detectable in 63-65% of the individuals who had received active or passive/active immunisation in mean titers between 1:32 and 1:64. Finally, only 32% of the renal allograft patients developed measurable anti-HBs antibodies, the titers of responders being still lower than in the hemodialysis patients. Side effects occurred following 10% of all vaccine injections and were always mild in nature. Within the 12 months observation period period following the first vaccination, 3 HBV events occurred in the 193 individuals: One aclinical case detected by a transient seroconversion against the hepatitis B core antigen, one anicteric and one icteric hepatitis case. The data illustrate the difficulties for active immunisation against hepatitis B of hemodialysis patients or of renal transplant recipients.

Antibodies, Viral↗
PubMed1983

Pneumatosis cystoides coli: a rare complication of colonoscopy.

A case of colonic pneumatosis cystoides intestinales (PCI) which occurred three days after a routine colonoscopy is presented. A review of the literature revealed only two other cases of PCI following colonoscopy. The close temporal association to the colonoscopy supports the mechanical hypothesis as the probably mechanism leading to intramural PCI.

Aged↗
PubMed1983

Proacrosin and the differentiation of the spermatozoa.

Using the indirect immunofluorescence staining technique, the occurrence and localization of proacrosin, the zymogen form of acrosin, was studied during spermatogenesis in the bull, ram, boar and rabbit. Proacrosin staining was demonstrable for the first time in the early haploid spermatid and increased with the differentiation of the spermatid to spermatozoon. The spermatozoon is covered by a cap-like structure of uniform fluorescence corresponding to the acrosomal compartment of the male gamete. No fluorescence could be found in diploid spermatogenic cells, i.e., in spermatogonia and spermatocytes. An identical developmental pattern of proacrosin was observed with the indirect immunoperoxidase staining technique. However, with this staining technique a distinct distribution of proacrosin staining was observed in the acrosome of epididymal and ejaculated spermatozoa of the bull, ram, boar, rabbit and man. Proacrosin seems to be distributed in the acrosome in granules rather than in the homogeneous form, as was indicated by the results of indirect immunofluorescence staining.

Acrosin↗
PubMed1983

Characterization of a Y/15 translocation by banding methods, distamycin A treatment of lymphocytes and DNA restriction endonuclease analysis.

A de novo 14/21 Robertsonian translocation and a familially inherited Y/15 translocation were observed in a male infant with anomalies of the external genitalia. The Y/15 translocation was confirmed by cultivating lymphocytes in a medium containing distamycin A and by determining the occurrence of the Y-specific DNA sequences by means of Hae III restriction endonuclease analysis. Any connection between the structural chromosomal abnormalities and the symptoms of the infant is highly improbable.

Chromosome Banding↗
PubMed1983

Carbonyldiimidazole/1-hydroxybenzotriazole activation in polymer phase synthesis of the arginine rich proalbumin hexapeptide extension.

The synthesis on different polymer phases of Arg-Gly-Val-Phe-Arg-Arg, the proalbumin extension, is reported. The peptide was prepared both on a 0.5% cross-linked polystyrene gel containing 2-oxoethyl bromide anchor functions and on a 1% cross-linked chloromethyl polystyrene. For temporary blocking of the amino groups we utilized the 2-(3,5-dimethoxyphenyl) propyl-(2)-oxycarbonyl (Ddz). The guanidino groups of the three arginine moieties were protected by the 4-toluenesulfonyl (Tos) group. As coupling procedure we used 1 equiv. carbonyldiimidazole (CDI)/2 equiv. 1-hydroxybenzotriazole (HOBt). The C-terminal activation of the Ddz-amino acids with CDI/HOBt made it possible to recover the excess Ddz-amino acids in 60-80% yield. We also investigated different procedures to cleave the 2-oxoethyl ester bond between the peptide and the polymer. This bond was completely stable against trifluoromethanesulfonic acid and was split by 1 N triethylamine in methanol/dioxane 1:1 (v/v) + 1 vol% 1 N NaOH. The optical rotation and HPLC properties of Arg-Gly-Val-Phe-Arg-Arg from this synthesis are identical to the product from a different synthesis published earlier.

Albumins↗
PubMed1983

Hepatocellular carcinoma and hepatitis B virus infection. Analysis of 75 cases from Switzerland.

The prevalence of serological markers of hepatitis B virus (HBV) infection was investigated in 75 patients with histologically confirmed hepatocellular carcinoma (HCC). Hepatitis Bs-antigen (HBs-Ag) was found in 30.8% and evidence of present or past infection in 61.5%. In a control group of 115 patients with liver cirrhosis of various etiologies in whom evidence of a coexistent HCC was lacking, the corresponding numbers were significantly lower (16.5% and 41.7% resp., p less than 0.05). Below the age of 65 years, markers of present or past HBV-infection were significantly more frequent than in patients above 65 years of age (p less than 0.025). All patients positive for HBs-Ag had an underlying cirrhosis; in seven cases, HCC was found in a non-cirrhotic liver. Alpha-fetoprotein measurements failed to identify patients with HCC in up to 43.6% of the HBs-Ag negative cases. It is concluded that HBV-infection does represent a cofactor in the malignant transformation of the liver, even in areas of lower incidence. Alpha-fetoprotein measurements need to be complemented by other investigations if early recognition of HCC is to lead to better survival.

Adult↗
PubMed1983

HLA-DR2 in two sibships with insulin-dependent diabetes mellitus.

We report two families selected from 124 genotyped Caucasian insulin-dependent diabetes mellitus (IDDM) families because of unusual features. In both families, all offspring are affected and four out of six bear the allele HLA-DR2 which is an uncommon phenotype among diabetic patients. Onset before the age of 1 year in all the patients of one family, association with optic atrophy in the other, and the existence of pairs of affected sibs of different HLA types in both, are infrequent findings and support the evidence of heterogeneity in IDDM.

Age Factors↗
PubMed1983

A direct demonstration of somatically paired heterochromatin of human chromosomes.

Human lymphocyte cultures were treated with different concentrations of 5-azacytidine for various lengths of time. This cytosine analog induces very distinct undercondensation in the heterochromatin of chromosomes 1, 9, 15, 16, and Y if applied in low doses during the last hours of culture. These regions are further distinguished by their intense distamycin A/DAPI-staining and highly methylated DNA. In interphase nuclei, these heterochromatic regions are frequently somatically paired. These somatic pairings are preserved up to the metaphase stage in the 5-azacytidine-treated cultures and are thus susceptible to direct analysis. The specific effect of 5-azacytidine on the heterochromatin of these chromosomes, its conserving effect on somatic pairing, and some of the consequences of the somatic pairing on the development of human chromosome aberrations are discussed.

Adult↗