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Biomedical subjects

H Weiss

Publications and source records attributed to H Weiss.

At least 271 records · Page 15Linked to original sources
PubMed1986

DNA distributions in human normal, precancerous and cancerous breast tissue. I. Ploidy and cell cycle distribution.

DNA distributions were recorded flow cytometrically in 19 normal, 23 precancerous tissues with epithelial proliferation and cell atypia (P1), 7 carcinomata lobularia in situ and intraductale carcinomas (P2) and in 44 invasive carcinomas of the human breast. The results were compared to histological findings, tumor staging and grading, lymph node involvement and age of the patients. DNA diploidy was found in all normal, 21 P1 tissues, 6 P2 tissues and 12 carcinomas; DNA aneuploidy in 2 P1 tissues, 1 P2 tissue and 32 carcinomas. Lobular carcinomas were preferentially involved in the DNA diploid group, duct carcinomas in the DNA aneuploid group. Cell cycle distribution analysis resulted in significantly higher percentages of cells in S- and G2M phase in DNA aneuploid carcinomas compared to normal and precancerous (P1, P2) tissues. The percentage of cells in G2M phase was significantly higher in DNA aneuploid carcinomas originating from patients younger than 50 years compared to patients older than 50 years. Correlations between the DNA-index, cell cycle distribution, lymph node involvement, tumour staging or histological type were not evident.

Adult↗
PubMed1986

Tumor localization and biodistribution of 99mTc-muramylpolypeptide (MPP) in the rat.

Muramylpolypeptide, extracted from Nocardia opaca bacteria and originally designed for immunotherapy of malignant tumors, proved to localize in malignant tumors, when labeled with 99mTc. In the tumor-bearing rat 99mTc-muramylpolypeptide (MPP) showed a fast turnover and optimum tumor to soft tissue ratios were obtained as early as between 30-60 min after application. The uptake mechanism in malignant tumors remains uncertain.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1986

Effects of nifedipine on cell resistance and cardiac toxicity--in vitro and in vivo experiments.

Nifedipine can enhance the cytotoxicity of antineoplastic drugs. The present paper describes characteristics of sensitive and acquired resistant cells prior to and after transplantation into nude mice and experiments to reverse the acquired resistance to Daunorubicin (DR) by Nifedipine. Resistant cells (HT/DR+) are characterized by prolonged doubling time and diminished drug sensitivity and drug uptake. HT/DR+ cells show a slightly increased number of polyploid cells. These characteristics are not changed after nude mouse transplantation. Nifedipine enhances the intracellular level of Daunorubicin and cytotoxicity in vitro and in vivo in case of HT/DR+ cells. But Nifedipine acts both in vitro and in vivo also on sensitive cells (HT). This could support the hypothesis that Nifedipine increases the toxicity, which could be confirmed by experiments on mice (B6D2F1 strain). But probably the increased incidence of toxic deaths is not due to increased cardiac toxicity. This increase of toxicity could limit the clinical usefulness of the combination of antineoplastic drugs with calcium channel blockers.

Animals↗
PubMed1986

DNA ploidy and proliferation characteristics of bowel polyps analysed by flow cytometry compared with cytology and histology.

56 human adenomatous bowel polyps and 44 samples of macroscopically unchanged bowel mucosa taken at a distance of 2-10 cm from the polyp were investigated by histology, cytology, and flow cytometry in respect to their dysplasia grade and DNA distributions. 30 human adenomatous polyps of the same localization were investigated by histology and flow cytometry; in 14 cases in addition to the DNA-patterns per se their changes mediated by heparin, a polyanion, were recorded. Histological and cytological investigations revealed mild dysplasia in 25 cases, moderate dysplasia in 43 cases and severe dysplasia in 18 cases. DNA aneuploidy was correlated with the histological finding of mild dysplasia three times, of moderate dysplasia twice and severe dysplasia five times. All other cases, also macroscopically unchanged bowel mucosa revealed DNA diploidy. In these diploid cases, cell cycle stage analysis yielded a higher proportion of cells in S-phase and G2M phase in adenomas with severe dysplasia in comparison to adenomas with moderate and mild dysplasia (P less than 0.05). Macroscopically unchanged bowel mucosa showed about the same values as adenomas with mild dysplasia. The heparin mediated increase in fluorescence intensity is different for adenomas with mild and moderate dysplasia, and attributed to the latter a higher proliferative activity (P less than 0.05).

Adenoma↗
PubMed1985

The primary structure of the iron-sulfur subunit of ubiquinol-cytochrome c reductase from Neurospora, determined by cDNA and gene sequencing.

The primary structure of the iron-sulfur subunit of ubiquinol-cytochrome c reductase from Neurospora mitochondria was determined by cDNA and genomic DNA sequencing. A first cDNA was identified from a cDNA bank cloned in Escherichia coli by hybridization selection of mRNA, cell-free protein synthesis and immunoadsorption. Further cDNA and geonomic DNA were identified by colony filter hybridization. The N-terminal sequence of the mature protein was determined by automated Edman degradation. From the sequence a molecular mass of 24749 Da results for the precursor protein and of 21556 Da for the mature protein. The presequence consists of 32 amino acids with four arginines as the only charged residues. The mature protein consists of 199 amino acids. It is characterized by a small N-terminal hydrophilic part of 29 residues, a hydrophobic stretch of 25 residues and a large C-terminal hydrophilic domain of 145 residues. The only four cysteines of the protein, which are assumed to bind the 2 Fe-2S cluster, are located in a moderate hydrophobic region of this large domain. Cysteines 3 and 4 are unusually arranged in that they are separated by only one proline. From sequence data the arrangement of the subunit in the membrane is deduced.

Amino Acid Sequence↗
PubMed1985

Prolonged confusion due to absence status following metrizamide myelography.

A case of absence status epilepticus resulted from metrizamide myelography. The acute confusional state following metrizamide myelography is briefly reviewed and compared with the confusional state resulting from adult-onset absence status. The similarities suggest that absence status may in fact be a relatively common cause of prolonged confusion following the use of metrizamide. Given the difficulty in clinical diagnosis and the excellent response to anticonvulsants, the possibility of absence status should be specifically excluded by EEG in any person suffering prolonged confusion following metrizamide myelography.

Aged↗
PubMed1985

Mitochondrial translation of subunits of the rotenone-sensitive NADH:ubiquinone reductase in Neurospora crassa.

The rotenone sensitive NADH:ubiquinone was isolated from mitochondria of Neurospora crassa as a monodisperse preparation with the apparent mol. wt. in Triton solution of 0.9 X 10(6). The enzyme is composed of at least 22 subunits with apparent mol. wts. in SDS between 70 and 11 kd. Six of the subunits with the mol. wts. 70, 48, 37, 25, 22 and 18 kd were radioactively labelled in the enzyme isolated from cells which had incorporated [35S]methionine in the presence of cycloheximide. These subunits are synthesized in the mitochondria. Eleven subunits were radioactively labelled in the enzyme from cells which had incorporated [35S]methionine in the presence of chloramphenicol. These subunits are synthesized in the cytoplasm. The site of translation of the other subunits could not be established by the pulse-labelling technique. The assignment of the mitochondrially synthesized subunits to unidentified reading frames on the mitochondrial DNA is discussed.

Mitochondria↗
PubMed1985

Monoclonal anti-cytokeratin antibody from a hybridoma clone generated by electrofusion.

Hybridomas producing mouse monoclonal antibodies to antigens of the human mammary carcinoma cell line, MCF-7, have been generated by electric field-mediated fusion at a frequency ten times higher than by polyethylene glycol. One of the monoclonal antibodies obtained recognizes a cytoskeletal structure restricted to epithelial cells and carcinomas with a distribution pattern resembling cytokeratin 19.

Animals↗
PubMed1985

[Sonographic detection of intracystic breast tumors].

While simple breast cysts account for the most common benign lesions of the breast, intracystic tumours, which most frequently occur as papillomas and papillary adenocarcinomas, are rare. In this paper we report on the clinical picture of these tumours, using our own material, and discuss the relevance of sonography in pre-operative diagnosis compared to conventional examination techniques such as mammography and pneumocystography.

Aged↗
PubMed1985

[Selective coronary angiography via flashing tomosynthesis].

To assess the value and significance of short-term tomosynthesis in judging the pathological condition of coronary vessels, the authors examined 34 patients with coronary heart disease. In comparison with 35 mm cinecoronary angiography, all angiographically determined vascular occlusions and stenoses were identified via short-term tomosynthesis. Comparison of the degrees of stenoses yielded good correlation (r = 0.85). Short-term tomosynthesis offers the advantage of employing smaller amounts of contrast medium to be injected; furthermore, the examination period is shorter, and exposure to radiation is also significantly less.

Cineangiography↗