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Biomedical subjects

K Lapis

Publications and source records attributed to K Lapis.

At least 271 records · Page 15Linked to original sources
PubMed1977

Light and electron microscopic study of hermorrhagic hepatitis induced by trimethyllysine and D-galactosamine.

In the present paper the effect of the pretreatment with epsilon-amino-trimethyllysine (TML) 10 mg/kg on the DGA-induced hepatitis in mice is described. TML-pretreatment was chosen because experiments indicated that TML treatment elicits processes in the liver similar to that occurring during regeneration on one hand, on the other hand because it was shown that DGA proved to be ineffective in newborn or in partially hepatectomized animals, that is to say on regenerating liver. It was expected that TML pretreatment would protect the animals against the hepatitis inducing effect of DGA. Unexpectedly pretreatment with TML had just the opposite effect, resulting in a severe hemorrhagic hepatitis in several animals. Biochemical and morphological studies are in progress to elucidate the mechanism of this peculiar effect.

Animals↗
PubMed1977

[Ultrastructure of cytoplasmic deposits and enzyme studies in human primary liver cancer].

Authors examined of the fine structure and electronhistochemical properties of deposits observed in two cases of primary liver carcinoma. It was established, that these deposits are formed by filaments consisting of fine granules of 70 A in diameter. On the basis of morphological picture and results of the investigation by enzymatic-dogestion technique it is believed, that deposits are the product of the rough-surfaced endoplasmic reticulum and their occurrence indicate the impairment of it's function. Deposits--as revealed by the enzymatic-digestion technique--consists of complex material, the protein component of which contain large quantities of basical amino acids.

Carcinoma, Hepatocellular↗
PubMed1977

Electron spin resonance spectra of chicken liver and hepatoma tissue embedded in paraffin.

ESR spectra of chicken liver and hepatoma tissue embedded in paraffin display signals characteristic of free radicals and paramagnetic complexes. Owing to embedding the spectrum is altered as compared to that of the native tissue but remains characteristic of the respective tissues. The spectra of tissues embedded in paraffin allow no more than qualitative conclusions to be drawn concerning the spectra of the native tissues, even if appropriate controls are applied.

Carcinoma, Hepatocellular↗
PubMed1977

In vitro carcinogenesis studies on mouse fibroblast cells.

Fibroblast cell lines were established from pulmonary explants derived from inbred CBA T6T6 mouse embryos. Cell lines controlled for the absence of spontaneous transformation were treated with 20=methylcholenthrene (0, 1 microgram/ml). The altered biological characteristics were studied during the process of the malignant transformation by the comparison of the untreated and 20-methylcholanthrene pretreated cell populations: the loss of contact inhibition and the connection between the malignant transformation and the arylhydrocarbon hydroxylase enzyme activity were investigated. No changes in the cell proliferation rate could be found following malignant transformation, but an increased resistance against altered circumstances was observed. In the course of passages, a gradual decreases in aryl hydrocarbon hydroxylase activity of the untreated line was seen, which disappeared or significantly decreased following 20-methylcholanthrene treatment, compared to the controls.

Animals↗
PubMed1977

Cytoplasmic aggregates in D-galactosamine induced liver injury.

D-galactosamine treatment leads to the formation of PAS-positive granules or aggregates in the cytoplasm of mouse liver cells. Ultrastructural observations show that the granules consist of particles surrounded by membranes of rough endoplasmic reticulum. Cytochemical results reveal that part of the particles is pronase-sensitive and amylase resistant, staining positively by the Thiéry silver proteinate method. The other part is stained positively by EDTA preferentional staining. According to the cyto-and histochemical results the granules consist of ribosomes and abnormal basic glycogen. The aggregates are removed from the cytoplasm mostly by lysosomal degradation.

Animals↗
PubMed1977

[Occurrence of nuclear bodies in acute viral hepatitis].

Needle-hepatic-biopsy of 10 patients with acute viral hepatitis was investigated by the aid of electron microscope. In the hepatocytes striking nucleolar alterations were observed, i.e. breakage and dispersion of the nucleolonema in the karyoplasma. Not infrequently nuclear bodies were seen. According to the present knowledge it can not be decided whether nuclear bodies are normal constituents of the hepatocytes or product of the impaired function. Complex nuclear bodies--in acute viral hepatitis--might indicate the presence of viral infection, on the other hand they might be the sign of the disturbance of the nuclear RNS-synthesis.

Biopsy, Needle↗
PubMed1976

Undulating membraneous structures associated with the endoplasmic reticulum in tumour cells.

The morphology and occurrence of tubuloreticular and undulating membraneous structures (TRS and UMS) associated with the endoplasmic reticulum were examined under normal and pathologic conditions. It was concluded that TRS and UMS are cytoplasmic inclusions of similar type but of different organization. The occurrence of UMS in a human cell line derived from a carcinoma of the lung and in a transplantable chicken hepatoma derived from an MC-29 virus-induced liver tumour is described.

Animals↗
PubMed1976

Cell surface changes observed in MC-29 virus-infected chicken-embryo fibroblast (CEC) cultures.

By transmission and scanning electron microscopic studies of MC-29 virus-infected CEC cultures, C-type virus particles were detected in the medium of infected cultures, in infected cells and in intracellular vacuoles. Virus budding was also observed. In the scanning electron microscope (SEM) so-called blebs appeared on the surfaces of the infected cells, in a number proportional to the concentration of the virus preparation. On the basis of the size of the blebs, it could be considered that virus formation was taking place in their center. In control cells, neither viruses nor blebs were observed. This method will presumably be suitable for the titration of virus preparations.

Animals↗
PubMed1976

Studies on in vitro carcinogenesis. I. Autoradiographic and biochemical study on the incorporation of labelled methylcholantrene into mouse embryonic cells.

The incorporation of radioactive labelled Methylcholanthrene into CBA/T6T6 mouse embryonic fibroblast cultures was studied by using light and electronmicroscopic autoradiographic and also liquid scintillation counting techniques. During 24 hrs treatment time at the applied Methylcholanthrene concentrations (0.01-2.5 mug/ml) the proportion of cells labelled with 3H-Methylcholanthrene and the number of grains above the cells showed a relationship with the duration of treatment and also with the doses. Up to 24 hrs all cells were labelled after treatment with 2.5 mug/ml whereas at 0.01 and at 0.1 mug/ml concentrations Methylcholanthrene could have been detected only 2 and 10% of the cell population resp. The presented results suggested that labelling index reached saturation level earlier than the average number of grains. Electronmicroscopic autoradiography revealed a rather even distribution of grains and there were no signs for preferential binding site of Methylcholanthrene. Biochemical separation showed that 59 and 44% of the radioactivity was bound to macromolecules at 1 and 24 hrs after commencing treatment resp.

Animals↗
PubMed1976

Incorporation of 3H-dibromodulcitol and 3H-dianhydrodulcitol into ascites tumor cells. Autoradiographic study.

The incorporation of 3H-Dibromodulcitol and 3H-Dianhydrodulcitol into S37 ascites tumor cells has been studied with autoradiography. Both drugs war incorporated very rapidly into the cells. The labeling of nucleus was higher than that of cytoplasm. A slight accumulation of grains was found above the condensed chromatin and along the membranes. The uptake of DAD has been more intensive than that of DBD.

Animals↗
PubMed1976

Biochemistry and enzyme induction in MC-29 virus-induced transplantable avian hepatoma.

For the biochemical characterization of a new transplantable hepatoma derived from the MC-29 virus-induced liver tumor, the macromolecular content and the inducibility of glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, and aryl hydrocarbon hydroxylase were compared in chicken liver and in this hepatoma. The alteration of the nucleocytoplasmic ratio was deduced from measurements of DNA, RNA, protein, and phospholipid contents of the whole cell homogenate and cell fractions. The increased nuclear and decreased cytoplasmic content of macromolecules suggests a dominancy of the nuclei in the tumor cells. Glucose-6-phosphatase and aryl hydrocarbon hydroxylase activities were lower by 60 and 80%, respectively, in the highly proliferating hepatoma than in the liver. In contrast, glucose-6-phosphate dehydrogenase activity increased in the hepatoma. However, enzyme inducers, such as methylcholanthrene, hydrocortisone, and insulin, were able to enhance the activity of these enzymes in the liver but had no stimulating effect on the hepatoma.

Animals↗
PubMed1976

[Mechanism of the antitumor action of 1,6-di-o-methane-sulfonide-2,3-4,5-dianhydro-1-iditol].

Under study was the effect of the drug in question on the growth of ascitic tumor NK/Ly. The drug, depending on its dosage, was found to suppress the tumor growth both in its accelerated and delayed stage of development and to show an instant effect. Its efficacy in the dosage employed would have no stage selective character. DMDAI blocks DNA synthesis and presumably impairs the metabolism of RNA ingradients, playing an important role in the mitosis and synthesis of DNA.

Animals↗
PubMed1976

[Electron microscopic changes of the intestinal mucosa following truncal vagotomy].

Ultrastructural changes on the mucosa of the jejunum and ileum after truncal vagotomy were studied in the dog. Tests performed 2, 3, 7 and 10 days, 2, 4, 5, 6, 7, 8 and 9 weeks as well as 4, 5, 6, 9 and 12 months after vagotomy showed no significant changes in the epithelial cells. The microvilli, smooth and rough surface endoplasmic reticulum, the free iebosomes and the terminal web area were completely intact. In some cells a swelling of the mitochondria was observed. It is concluded that vagotomy causes no such morphological changes of the intestinal mucosa which could explain postvagotomic diarrhoea.

Animals↗