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Biomedical subjects

K Lapis

Publications and source records attributed to K Lapis.

At least 217 records · Page 12Linked to original sources
PubMed1980

epsilon-N-trimethyl-lysine: a natural cell component with mitogenic activity.

The blastogenic capacity of a new mitogenic agent, epsilon-N-trimethyl-lysine (TML) was examined on human peripheral blood lymphocytes. The changes in relative DNA and histone content after TML treatment testified that activated lymphocytes passed through the whole cell cycle. The comparison of the 3H-TdR incorporation rate into unseparated T-B lymphocyte and purified T lymphocyte cultures suggested a preferential effect on the thymidine incorporation of T lymphocytes. TML induced preferentially high responses in cases of blood cells taken from women. The possibility of DNA repair mechanism could be excluded. The results of combined TML-PHA treatment experiments suggested a difference in the trigger mechanism of these two mitogenic compounds.

Adult↗
PubMed1980

Hepatic lesions in Lebistes reticulatus induced by N-nitrosodiethylamine.

The effect of N-nitrosodiethylamine (NDEA) on the aquarium fish, Lebistes reticulatus (guppy) has been investigated. The aquarium water contained 10 to 200 parts per million of NDEA. The LC50/30 for NDEA was 100 ppm. Sub-chronic experiments were carried out using 25 and 50 ppm for 90 days. The liver alterations were investigated morphologically. Initially, diffuse necrosis of hepatic cells, disorientation of hepatic structure and cyst-formation appeared. The degenerative lesions were followed by multiple foci of regenerating hepatic cells. In the later period of the experiment, hyperplastic nodules of hepatocytes, cholangiofibrosis, cystic cholangiomas, hepatocellular and cholangiocellular carcinomas could be observed in the treated animals. The following conclusions have been reached: 1. Aquarium fish can be used as a model for short-term, in vivo carcinogenesis experiments. 2. Lebistes reticulatus is a suitable strain for use as a positive control with NDEA. 3. With this model, the process of carcinogenesis can be followed histologically. 4. The process is irreversible and some of its features may be used as an early indicator in the screening of possible carcinogenic substances.

Animals↗
PubMed1980

[Ultrastructure of pregnancy granuloma (angiogranuloma)].

The granuloma of pregnancy (angiogranuloma) has been studied by light-and electron microscopy. It has been revealed that granuloma of pregnancy consists chiefly of capillaries and undifferentiated connective tissue. It is a hyperplastic proliferative growth developing on the hormonal basis. In the case reported under the basement membrane presence of an electron lucent layer of fibrillar structure has been observed. Authors suppose that this phenomenon later will successfully be used in morphological differential diagnostics.

Adult↗
PubMed1980

[Liver regeneration characteristics in young rats in allyl alcohol lesion of the periportal areas].

The authors analyzed ultrastructural changes in hepatocytes of weanling rats, induced by allyl alcohol (0.03 ml/kg). The most severe lesions developed in mitochondria of the periportal field of liver lobules during the first 24 hours following alcohol administration. Early signs of the regeneration were also seen in the periportal field 24 hours after exposure. Three types of dark hepatocytes were distinguished: (1) polygonal cells with the dilated endoplasmic reticulum, increased size and number of mitochodria; (2) stellate cells with the remarkably increased rough endoplasmic reticulum showing free ribosomes and a lot of large mitochondria; (3) cells consisting of irregularly arranged rough endoplasmic reticulum and a great number of small mitochondria. Large hepatocytes containing an insignificant number of organellas were seen in the later stages of the regeneration. The data obtained warranted a suggestion that the cells described represent different phases of hepatocytic regeneration.

Alcohols↗
PubMed1980

Cytochemical study of peritoneal macrophages in carrageenan-treated immunosuppressed mice.

In our examinations the cytochemical characters of the peritoneal macrophages of immunosuppressed mice (Is-PM) were studied. It was stated that the acid phosphatase activity of their lysosomal system decreased in comparison to control cells (N-PM). In Is-PM cells the polyanion content of the cell-coat and the expression of their ConA receptors decreased, while the glycos- and galactosaminoglycan (GAG) content showed a decrease on the surface of every cell of the population. On the first day following carrageenan treatment, acid phosphatase activity of the cells was very low, the GAG content and the conA receptors of the cell-coat disappeared. The characteristic lysosomal alterations could still be observed on the 6th day after treatment. On the basis of our observations treatment with carrageenan impaired not only the lysosomal system of macrophages, but the cell surface too. These cytochemical changes may explain the dramatic decrease in macrophage function observed in carrageenan treatment.

Acid Phosphatase↗
PubMed1979

Electron spin resonance (ESR) spectrum of paraffin embedded human liver tissue. A possible method for the estimation of copper content.

Human liver tissues embedded in paraffin wax for histological examination have been studied by Electron Spin Resonance (ESR) spectroscopy. A signal was detected at g approximately 2.05 section of the spectrum. The amplitude of this signal was correlated with the copper content of the embedded specimens measured by flame atomic absorption technique. The positive correlation which has been found can make ESR spectroscopy suitable for estimating the copper content of tissues without damaging the sample. The limits and errors of this method have also been analysed.

Copper↗
PubMed1979

Acridine orange staining of the mammalian fibroblast cell coat.

Acridine orange selectively binds to glycos- and galactosaminoglycan (GAG) compounds in the presence of Na+ in low concentrations. We have worked out a cytochemical method, which is suitable for the specific demonstration of surface GAG components. The method consists of a glutaraldehyde prefixation, an acridine orange block-staining for 48 h and an OsO4 postfixation for some hours. The specificity of the staining was verified with the help of fluorimetric--in vitro--measurements and enzymatic digestions, respectively.

Acridine Orange↗
PubMed1979

Chromatin proteins as a possible target for antitumour agents: alterations of chromatin proteins in dibromodulcitol treated Yoshida tumors.

The effect of dibromodulcitol (DBD) on Yoshida sarcoma chromatin components has been investigated. Measurements on the radioactivity of nuclear components after in vivo treatment with [3H]DBD for 1 h indicated preferential drug binding to the high molecular weight component of the nuclear residual acidic protein (non-histones) and also to Histone 1 (H1) (very lysine rich, F1). Two-hour DBD treatment resulted in partial degradation and reduced [3H]leucine incorporation into the same fractions of chromatin. However, 6 h after DBD treatment, the synthesis of the degraded chromatin proteins began and by 24 h was completed. During the same treatment period the composition of chromatin showed a remarkable alteration; 2 h after DBD treatment the amount of the nuclear residual acidic proteins relative to DNA decreased by approx. 50%, but returned to control value 24 h after drug treatment. This in conjunction with the data on [3H]leucine incorporation suggests that certain chromatin proteins are degraded and subsequently newly synthesised after DND treatment resulting in an exchange of chromatin components. The formation of a nucleohistone complex between H1 and DNA was inhibited by pretreatment of H1 and DBD, dianhydrodulcitol (DAD) and bischloroethylnitrosourea (BCNU).

Animals↗
PubMed1979

Allyl alcohol-induced changes in the rat exocrine pancreas.

A histologic, histochemical and electron microscopic study was carried out on the rat exocrine pancreas 6-96 h after a single allyl alcohol intake. Histologically, acidophilia, necrosis and vacuolation of the pancreatic acinar cells were observed. Histochemically, a low but evident alcohol dehydrogenase activity could focally be demonstrated in the pancreatic acinar cell cytoplasm of the experimental and control rats. By electron microscopy, cytoplasmic lipid droplets, mitochondrial degeneration and necrosis were found in the acinar cells. Focal cytoplasmic degradation and vacuolation were seen in acinar, centroacinar and ductular cells of the pancreas. The findings are regarded as the consequence of the toxic action or acrolein that originates after allyl alcohol oxidation by alcohol dehydrogenase. Analogies between the liver and the pancreas in their response to acute allyl alcohol and chronic ethanol intake are discussed.

1-Propanol↗
PubMed1979

Analysis of the electron spin resonance spectrum of human liver tissue embedded in paraffin.

The ESR spectra of the liver samples embedded in paraffin of newborn, adult, cirrhotic and control individuals always display the g approximately 2.05 signal and occasionally also the g = 4.3 line and the signal of free radicals. In adults, the amplitude of the g approximately 2.05 signal is negatively correlated with that of the g approximately 4.3 signal; in infants aged from three months to one year this correlation is positive. The copper content of the liver is in linear correlation with the amplitude of the g approximately 2.05 signal. The hyperfine structure of the part of the g approximately 2.05 signal recorded at low magnetic field may be of three types: it may correspond to Cu2+ centers of axial symmetry of type I, II or I + II. The parameters of the signal are the following: type I center, g = 2.35 +/- 0.05, g = 2.05 +/- 0.01, A < 100 gauss; type II center, g = 2.25 +/- 0.03, g = 2.05 +/- 0.01, A = 160 +/- 20 gauss. On the basis of the amplitude of the g approximately 2.05 signal, the copper content of the liver tissue can be estimated from paraffin blocks with an error of 30%, without losing the tissue embedded for histological examination.

Adolescent↗