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K D Zang

Publications and source records attributed to K D Zang.

At least 109 records · Page 6Linked to original sources
PubMed1979

Quantitative studies on the arrangement of human metaphase chromosomes. VI. The association pattern of acrocentric chromosomes in patients with trisomy 13.

The association pattern was studied in 1182 mitoses of 21 patients with trisomy 13 and in a control group. In addition, 173 trisomic mitoses were compared with the same number of diploid mitoses in a case of mosaicism. The number of mitoses with associations was no higher in the trisomic cells than in cells with normal karyotypes. Some differences were observed in the frequency of associations per cell and of the types of associations in the patient group and in the trisomic cells of the mosaic case. The number of associations in which more than two acrocentric chromosomes were involved was unexpectedly low in the cells with a supernumerary chromosome 13. The results are interpreted as suggesting the existence of a compensatory mechanism activated by the additional acrocentric chromosome.

Cell Nucleolus↗
PubMed1979

Karyotypic variations in human meningioma cell cultures under different in vitro conditions.

Examined were how changes of the culture medium, cultivating procedure and cultivating time will influence numerical representation of different karyotypes in a total of 27 cell cultures of meningiomas with two or more cytogenetically distinguishable cell lines. It could be shown that in medium I (80% Mc Coy 5 A, 20% fetal calf serum) more cell lines with a higher degree of hypodipoidy occurred than in medium II (50% TC 199, 40% bovine amniotic fluid, 10% calf serum). The number of cells with normal karyotype was higher in cultures which were grown from trypsinized biopsy material in stationary flasks when compared to particle cultures in roller tubes. Cells with a normal karyotype also increased after 1--6 subcultures. By demonstration of SV 40 tumor antigen it could be shown in two cultures that these normal mitoses derived from tumoral and not from stromal tissue.

Antigens, Viral↗
PubMed1979

Distal 2q duplication: report of two familial cases and an attempt to define a syndrome.

Two cases of partial trisomy 2q are described, both resulting from a balanced translocation in one of the parents. In one case the chromosomes 2 and 11 were involved [paternal karyotype: 46,XY,t(2;11)(q33;q23)]; in the second case, chromosomes 2 and 8 [paternal karyotype: 46,XY, t(2;8(q32;p23)]. When the two patients were compared to the few cases reported in the literature, it was concluded that the associated clinical syndrome is characterized by severe psychomotor retardation and relatively mild abnormalities involving skull and facies.

Abnormalities, Multiple↗
PubMed1979

SV40-related T-antigen expression in human meningiomas with normal and G-22-monosomic karyotype.

Six of 16 meningiomas tested in early subcultures by indirect immunofluorescence showed SV40 T-antigen. Two different antisera specific for T-antigen were used. One serum gave a positive reaction with six tumours and the other with only two. In one T-antigen positive meningioma, the typical nuclear fluorescence changed, beginning with the second subculture, into an unusual brilliant granular pattern irregularly distributed over the nuclei. In six meningiomas, a specific chromosome aberration (monosomy G 22) was established. However, up to now, no clear correlation between karyotype and T-antigen expression could be found: cells from three meningiomas with positive reactions had normal karyotypes, whereas those from three tumours with typical chromosome loss showed no T-antigen.

Antigens, Neoplasm↗
PubMed1978

Quantitative studies on the arrangement of human metaphase chromosomes. V. The association pattern of acrocentric chromosomes in human meningiomas after the loss of G and D chromosomes.

The association pattern was studied in 2715 mitoses of 90 meningiomas with different numbers of acrocentric chromosomes. In cells with monosomy 22, a significant increase of mitoses with associations was observed in comparison to cells with a normal karyotype. The number of associating acrocentric chromosomes was highly significantly increased. This surplus was not only caused by a highly significant increase of associating G chromosomes but also of D chromosomes. The loss of further acrocentric chromosomes had no significant influence on the number of mitoses with associations or the number of associating chromosomes. Based on the well-known correlations between the nucleolus organization and the association pattern, the results seem to indicate a compensation mechanism among the nucleoles organizing regions (NOR's) which keeps the supply of nucleolar material constant and simultaneously causes a higher association tendency between the remaining acrocentric chromosomes. The increase of associations in the 22 monosomic cells was interpreted as a overcompensation after the loss of only one NOR.

Cell Cycle↗
PubMed1976

Mitosis of maternal lymphocytes in the presence of fetal cells: possible implication in prenatal diagnosis from fetal blood samples.

The suppression of proliferation of maternal lymphocytes by the lymphocytes of their own male newborns have been tested in a PHA-induced two-way stimulation system. The mixed lymphocyte cultures of 6 out of 12 such mothers/son pairs had 23--50% metaphases with 46,XX karyotype. In 2 more cases 10% maternal metaphases have been observed. Hence, it appears that fetal lymphocytes are unable to suppress the proliferation of maternal cells completely.

Cytodiagnosis↗
PubMed1976

SV 40 related papova-viruses in human meningiomas.

Human meningiomas show characteristic chromosome aberrations very similar to those reported in human cell cultures experimentally transformed by Simian virus 40 (SV 40). Three out of eight meningiomas tested showed SV 40 specific tumor antigen but no virus capsid antigen. Experiments to rescue virus were successfully performed. Electron microscopic studies of these cell cultures revealed cytoplasmic inclusions containing virus particles which corresponded in size and morphology to Papova viruses.

Antigens, Viral↗
PubMed1975

Cytological and cytogenetical studies on brain tumors. VI. No evidence for a translocation in 22-monosomic meningiomas.

The recently detected reciprocal translocations in chronic myeloic leucemia (CML) and Burkitt's lymphoma (BL) made it necessary to clarify if meningiomas really show the described monosomy 22 or also a translocation. In 10 out of 12 meningiomas a total or partial translocation of the missing chromosome 22 to another chromosome could be ruled out by fluorescence banding analysis. Two meningiomas showed marker chromosomes of such a complex composition that it was impossible to decide if a 22 translocation was present or not. From these results it was concluded that meningioma cells, in contrast to CML and BL, show almost regularly a loss of a definitive part of their genome.

Aneuploidy↗
PubMed1975

Simian virus 40-related antigens in three human meningiomas with defined chromosome loss.

Two out of seven meningiomas tested in early cell cultures by indirect immunofluorescence staining showed simian virus 40 (SV40)-related tumor (T) antigen. In one tumor 90% of the cells were positive. An additional SV40-related antigen (U) was found in 10% of cells of a third tumor. These findings indicate that the meningioma cells showing a positive reaction are transformed by a papova virus that has at least partly the same antigenic properties as SV40 virus. SV40-related viral capsid (V) antigen was absent in all the meningiomas tested. No virus infectious for African green monkey kidney (AGMK) cells could be isolated. The tumors positive for T and U antigens showed the chromosome aberration typical for human meningiomas, i.e., the loss of one chromosome, G-22. The T-antigen-positive tumors showed further hypodiploidization. Experiments to rescue virus from the T-antigen-positive tumors showed further hypodiploidization. Experiments to rescue virus from the T-antigen-positive meningioma cells were performed: fusion of cells pretreated with 8-azaguanine with cells premissive for SV40 led to a low percentage (0.01-0.05%) of V-antigen-positive nuclei in heterokaryon cultures. On the basis of these results, the possibility of a correlation between the meningioma, a relatively common intracranial tumor in man, and an SV40-related papova virus must be considered. It remains to be shown whether this virus is a causative agent for human meningiomas.

Adult↗
PubMed1975

[Chromosome studies on human fibroblast cultures following exposure to cyproheptadin].

Cyproheptadin was tested on chromosomes in fibroblast cultures of children for its possible mutagenic efficacy. Neither 24-hour exposure to Cyproheptadin at concentrations of 8-16 mg/l medium nor a chronic exposure for 8-11 weeks at a concentration of 8 mg/l caused any discernable chromosomal mutations. At concentrations between 8-16 mg/l reversible cytomorphological and cytochemical changes occured; 32 mg/l suppressed cell division and higher concentrations (64-128 mg/l) brought about irreversible changes leading to cell death. These reactions were rather in vitro cytotoxic effects of unspecific nature.

Cell Division↗
PubMed1975

Cytological and cytogenetical studies on brain tumors. V. Preferential loss of sex chromosomes in human meningiomas.

Twelve out of 88 cytogenetically examined meningiomas of female patients showed, in addition to the typical loss of a chromosome 22, a loss of 1 or more chromosomes of group C. Among them 8 tumors had less than 8% cells with Barr-body-like particles, whereas in one tumor 12% and in 3 others over 20% Barr bodies were found, which, based on control studies, were classified as sex-chromatin negative, partly positive, and positive, respectively. In one case the loss of an X chromosome was verified by Giemsa banding. In 6 out of 24 meningiomas of male origin, the chromosomal morphology and association pattern strongly indicated that besides the loss of a chromosome 22, the Y chromosome was also missing. Moreover, the loss of the male sex chromosome could be ascertained in 4 tumors by the conspicuous absence of Y fluorescence in interphase nuclei and in metaphase plates after fluorescence staining. The findings are discussed in connection with the gonosomal loss in other human tumors and in old age.

Adult↗