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Biomedical subjects

H Busch

Publications and source records attributed to H Busch.

At least 361 records · Page 20Linked to original sources
PubMed1976

Effects of adriamycin on ultrastructure of nucleoli in the heart and liver cells of the rat.

Ultrastructural studies of the effects of adriamycin on liver and cardiac cell nucleoli of the rat showed that nucleolar segregation occurred within 1 hr after an i.v. injection of a 40-mg/kg dose. Between 3 and 27 hr after this single dose, liver cell nucleoli progressively reverted to a normal ultrastructure. Nucleoli of rat myocardial cells did not recover but underwent further fragmentation, segragation, and conversion to ring-shaped structures. The ultrastructural alterations of myocardial cell nucleoli may represent an important aspect of adriamycin toxicity.

Animals↗
PubMed1976

Quantitative analysis of the distribution of 3H-leucine in acid soluble chromatin proteins of Noviknoff hepatoma cells separated by two-dimensional polyacrylamide gel electrophoresis.

The acid soluble proteins of Novikoff hepatoma chromatin were labeled linearly with 3H-leucine for 16 minutes. Analysis on two-dimensional polyacrylamide gels showed that 13 of the 18 stained proteins were detected by autoradiography after a 16-minute in vitro incubation. The labeled molecules include the histones H2A, H2B, H3, and H4; and proteins A3, Aj, A8, A8', A15, A16, A24, B7, and B13. Relatively large amounts of isotope were incorporated into two other proteins, A3 and Aj, in addition to the histones. Some proteins, notably Aj, A8, A8' and A16 were labeled to a greater extent than would be expected on the basis of uptake of Coomassie Brilliant Blue R. None of the labeling patterns were characteristic of a precursor-product relationship either the histones or the nonhistone proteins.

Animals↗
PubMed1976

Homochromatographic and immunological analysis of controls of nucleolar gene function.

To compare regulation of nucleolar function of tumors and other tissues, it was necessary to develop assays of the fidelity of ribosomal DNA readouts. For this purpose, homochromatography analyses of complete T1 ribonuclease digestion products of the in vivo labeled 45 S preribosomal RNA were compared with those of 18S and of 28 S ribosomal RNA. Homochromatography analysis of the in vitro readout product of isolated nucleoli showed the presence of many large marker nucleotides of the in vivo 45 S preribosomal RNA. Moreover, no other large oligonucleotides were detected. The in vitro readout product of nucleolar chromatin had the same T1 ribonuclease digestion products, including the large marker of oligonucleotides. However, the in vitro readout product of nucleolar DNA contained no large marker T1 ribonuclease oligonucleotides. These results indicate that the fidelity of nucleolar readouts is controlled by regulatory proteins of the nucleolar chromatin. Differences were found in nucleolar proteins of normal rat liver and Novikoff hepatoma by immunological analyses. The possibility exists that differences in readout rates of tumor and other nucleoli are related to the protein difference detected by these immunological studies.

Animals↗
PubMed1976

Antigenically active nonhistone chromatin proteins in cancer cells.

Two-dimensional polyacrylamide gel electrophoresis shows that in nuclei of Novikoff hepatoma ascites cells there are approximately 75 proteins in the chromatin fraction soluble in 3 M NaCl:7 M urea. Dialysis of this fraction to an ionic strength of 0.15 produces a soluble fraction and a precipitate. The proteins in the soluble fraction have been reported to be active in gene control. Antibodies to the soluble fraction distribute diffusely throughout the nucleus, and antibodies to the precipitate localized primarily in the nucleolus and the nuclear ribonucleoprotein network. The nucleolar proteins differ from the extranucleolar proteins in antigenicity and labeling patterns. The development of methods for isolation, purification, and identification of nuclear proteins provided the opportunity for analysis of chromatin antigens in tumor cells. Utilizing two-dimensional preparative polyacrylamide gel techniques as well as conventional procedures, several nuclear proteins have been isolated in electrophoretically homogeneous states including protein A-24, a histone-like nonhistone protein; C-14, a protein that stimulates nucleolar RNA polymerase; and a chromatin antigen soluble in 3 M NaCl:7 M urea that remains soluble after dialysis to 0.15 M NaCl to precipitate the histones and the DNA. This antigen has been found in the chromatin of both the Novikoff hepatoma and the Walker 256 carcinosarcoma but not in the chromatin of either normal or regenerating liver. It is a nonhistone nuclear protein as indicated by its amino acid analysis in which the ratio of the number of acidic to basic amino acids is approximately 1.4. Further studies are in progress on the function and structure of this chromatin protein. As an approach to analysis of relative rates of synthesis of this antigen and otherproteins, the products of translation of messenger RNA of Novikoff hepatoma and normal liver are being analyzed by autoradiography of two-dimensional electrophoretic gels.

Animals↗
PubMed1976

Ultrastructural study of pulmonary bleomycin toxicity.

Ultrastructural manifestations of bleomycin A2 toxicity in the human lung were studied in three patients. In addition to the appearance of nucleolar fibrillar centers, an increase in membranous, beaded, and granular nuclear bodies was found in nuclei of type 1, type 2 alveolar epithelial cells, and interstitial fibroblasts in all treated patients. Few such nuclear bodies were found in specimens of untreated patients.

Adult↗
PubMed1976

A general concept for molecular biology of cancer.

The demonstrations that "fetal" isozymes and other fetal or "oncodevelopmental" antigens are present in tumor cells has led to the general concept that genes normally silent in adult tissues are activated during the neoplastic process. Recent evidence that some chromatin proteins of tumor cells are fetal antigens has suggested that some of the "switches" involved in gene activation for tumor growth may also be fetal or oncodevelopmental. These results have led to current theoretical concept that fetal gene derepressors interact with the genome to produce messenger RNA for the protein products involved for growth, invasiveness, and metastasis. These processes may not be controllable in adult cells because of the lack of inhibitors, which were present during embryonic development but are not produced in adult tissues.

Animals↗
PubMed1976

[Studies on a novel antidepressant (viloxazin) by means of time-series analysis of TV data].

19 depressed patients were treated with viloxazin (n = 9) or amitriptyline (n = 10) in a double-blind-trial. TV-tapes were produced for each patient on day 0, 10 and 20. These tapes were analysed with respect to the intensity of depression by 4 independent raters under the condition of a time-blind analysis. These 3 TV-tapes could easily be discriminated in the sense of a decreasing depressivity. The results suggest that the effect of viloxazin has a shorter delay than that of amitriptyline.

Amitriptyline↗
PubMed1976

[Intrathoracic parallel heart transplantation in the dog].

The authors report on intrathoracic parallel heart transplantation which was experimentally tried on 10 mongrel dogs. The described technique is advantageous since it can be performed without extracorporeal circulation. The results of hemodynamic studies on graft and recipient heart vindicate further employment of this technique to study several problems of heart transplantation still unsolved.

Animals↗
PubMed1976

[Rater-specific variables in judging depressive patients (author's transl)].

Four raters judged their sympathy towards 19 depressed patients and also the intensity of their disease using thermometer-scales. It was exmained whether there was a correlation between the two scores. A rater-specifuc varuabke was fiybd fir eacg if tge fiyr raters. The importance of these variables for further investigations is discussed.

Depression↗
PubMed1975

Structural analyses of mammalian ribosomal ribonucleic acid and its precursors. Nucleotide sequence of ribosomal 5.8 S ribonucleic acid.

The nucleotide sequence of ribosomal 5.8 S RNA (also known as 7 S or 5.5 S rRNA) from Novikoff hepatoma ascites cells has been determined to be (see article). Estimations of the secondary structure based upon maximized base pairing and the fragments of partial ribonuclease digestion indicate that there may be five base-paired regions in the molecule, three forming a folding of the termini and two forming secondary hairpin loops. The sequence of Novikoff hepatoma 5.8 S rRNA is about 75% homologous with that of yeast 5.8 S rRNA (Rubin, G.M. (1973) J. Biol. Chem. 248, 3860-3875) and similar models for secondary structure are proposed. Both models contain a very stable G-C rich hairpin loop (residues 116 to 138), a less stable A-U-rich hairpin loop (residues 64 to 91) and two symmetrical bulges (residues 15 to 25 and 40 to 44).

Animals↗
PubMed1975

Nuclear ribonucleoprotein complexes containing U1 and U2 RNA.

Nuclear ribonucleoprotein (RNP) complexes that contain the U1 and U2 RNA of chromatin of Novikoff hepatoma cells were extracted with 0.01 M Tris-HCl (pH 8.0) after the nuclei were initially washed with 0.075 M NaCl and 0.025 M EDTA (pH 8.0). These RNP complexes were purified by chromatography on Sepharose 6B columns and centrifugation on sucrose density gradients. The identity of the U1 and U2 RNA in these particles was established by their electrophoretic mobility in polyacrylamide gels and their T1 RNase fingerprints which were identical with those of authentic U1 and U2 RNA (R. Reddy et al. (1974), J. Biol. Chem.249, 6486-6494; H. Shibata et al. (1974), Mol. Cell. Biochem. 4, 3-19). The nuclear riboncleoproteins had a buoyant density of 1.47 g/ml in CsCl gradients. Two-dimensional polyacrylamide gel electrophoresis of their proteins showed these RNP complexes contain 10 polypeptide spots, of which two are phosphorylated in vivo.

Animals↗