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Biomedical subjects

K Lapis

Publications and source records attributed to K Lapis.

At least 109 records · Page 6Linked to original sources
PubMed1990

[Pathobiology of human primary benign and malignant liver tumors].

Authors elaborated 35 surgically removed tumors of liver by morphological and biochemical methods. From tumors 5 proved to be hepatocellular adenoma (HCA), 12 to focal nodular hyperplasia (FNH) and 18 to hepatocellular cancer (HCC). On the basis of enzyme histochemical and biochemical examinations, HCA is characterised by "normal" enzyme pattern. By the above method, FNH can be divided into two groups, characterized with "normal" and "abnormal" (tumor-like) enzyme change, while HCC proved to be very heterogeneous. Majority of HCA and FNH cases, according to data gained by flow cytometer, were of diploid DNA content. In majority of HCC cases, DNA diploid was aneuploid, but in three cases normal DNA content was observed. The above mentioned examination revealed several different characteristics of human hepatic tumors, compared to experimentally created tumors of liver.

DNA, Neoplasm↗
PubMed1989

Two human melanoma xenografts with different metastatic capacity and glycosaminoglycan pattern.

Two human melanoma xenografts were compared with respect to their in vivo growth and metastatic potentials as well as glycosaminoglycan patterns. The less differentiated HT 168 tumor showed faster growth at primary sites and a more pronounced capacity for metastasis into the liver. Although chondroitin sulfate was the dominant glycosaminoglycan subtype in both tumors, the more invasive xenograft had a higher heparan sulfate/chondroitin sulfate (HS/CS) ratio. We suggest that tumor progression is influenced by this ratio in this human melanoma system.

Animals↗
PubMed1989

Growth inhibition of MXT mammary carcinoma by enhancing programmed cell death (apoptosis) with analogs of LH-RH and somatostatin.

BDF female mice inoculated with MXT mammary adenocarcinoma were treated for 30 days with microcapsules of the luteinizing hormone-releasing hormone (LH-RH) agonist D-Trp-6-LH-RH (releasing 25 micrograms/day for 30 days), microcapsules of the somatostatin agonist RC-160 (liberating 25 micrograms/day for one month), or the combination of these peptides. Bilateral surgical ovariectomy was performed in one group which served as an additional control. Tumor volume was measured weekly during the treatment period of 30 days. When tumor volume changes in the treated groups were compared to the corresponding changes in controls, the combination of D-Trp-6-LH-RH and RC-160 was the most effective in inhibiting tumor growth and approached the effect of surgical ovariectomy. At the conclusion of the experiment, tumor weights were also measured. All peptide analogs inhibited tumor weight by 42 to 63%. In the D-Trp-6-LH-RH treated group, ovarian weights and uterine weights decreased by 48% and 52%, respectively, as compared to controls. Histologically, the regressive changes in tumors caused by the treatment with RC-160, D-Trp-6-LH-RH and their combination were characterized by the coexistence of apoptosis (programmed cell death) and coagulation necrosis. The transition of apoptosis into coagulation necrosis was a common finding. The term 'apoptotic index' is proposed for the ratio of tumorous glands containing apoptotic cells. The apoptotic index was higher in the treated groups than in the control.

Adenocarcinoma↗
PubMed1989

The effect of L-leucine methyl ester on the phagocytosis and amino acid incorporation of murine peritoneal cells.

Murine peritoneal macrophages were treated in vitro with L-leucine methyl ester (0.25-5.0 mM). This treatment resulted in an inhibition of the amino acid incorporation into the cells both at 4 degrees C and 37 degrees C during a relatively short incubation period. The adherence of macrophages was not changed by the treatment. Bacterial phagocytosis was partly influenced: Leu-OMe did not change the binding but the engulfment of opsonized bacteria was blocked. Damage of the plasma membrane caused by Leu-OMe was not so serious as that produced by specific anti-PEC antiserum. Leu-OMe is a lysosomotropic agent accumulated preferentially by lysosomes. The vacuolization of the cells and the dilatation of the vacuoles are evidences for the intracellular damage. In the early phase this damage is characterized only by the leakage of the cytoplasm, later the damage of the plasma membrane can also be demonstrated.

Animals↗
PubMed1989

Immunoelectron microscopy of human retroviruses.

The ultrastructural detection and identification of human retroviruses--HTLV (human T-cell lymphotropic virus) and HIV (human immunodeficiency virus)--have become an everyday task for pathologists and virologists as well as for cell and molecular biologists. The development of better and conventionally available immunocytochemical techniques, such as pre- or postembedding immunocytochemical methods, cryofixation-variants and low temperature embeddings, have made it possible to use them in this field. With the help of these methods the structural proteins of HTLV-I and HIV have been identified in infected cells. The virus assembly at the cell membrane has also been described in detail. Using these methods the incorporation of human transplantation antigens into the envelope of these viruses can be followed. Future studies should establish the pathological significance of this process.

Humans↗
PubMed1989

Ethanol treatment inhibits the development of diethylnitrosamine-induced tumors in rats.

Effect of ethanol (20% in drinking water) or acetone (1% in drinking water) treatment was investigated on N-diethylnitrosamine (DEN), acetyl-aminofluorene (AAF) and partial hepatectomy (PH) induced hepatic tumors in rats. Simultaneously with the morphological detection of foci and nodules in the liver of the sacrificed rats, the activities of isozymes of cytochrome P450IIE gene subfamily responsible for the oxidation of ethanol or acetone (as aniline hydroxylase) and also the activity of aminopyrine N-demethylase were determined. Nodules could be detected after DEN, AAF and PH treatment with and without combination with acetone, however nodules did not developed in ethanol treated animals even 6 months after the DEN injection. As expected acetone or ethanol selectively increased the activity of aniline hydroxylase without a general induction of P-450 enzymes. It is suggested that the induction of P-450IIE isoenzymes per se is not connected to the preventive effect of ethanol on DEN induced carcinogenesis.

Animals↗
PubMed1988

The barrier-like role of activated connective tissue against the spread of supraglottic laryngeal carcinoma.

Light microscopic investigations of whole organ serial sections of 15 laryngectomy specimens with supraglottic carcinomas and comparative electron microscopic studies of the upper and lower poles of the tumors were carried out. The ultrastructure of different poles of the same supraglottic tumors was investigated and showed a more progressive fibrillogenesis with an activation of the connective tissue elements of the border on the lower pole of the malignancy. A significant role is attributed to the barrier-forming feature of activated connective tissue with respect to the inhibition of the extension of tumor into the glottic region.

Carcinoma, Squamous Cell↗
PubMed1988

Ultrastructural aspects of the human primary liver cancer.

First a brief delineation of the general ultrastructural characteristics of the human primary hepatocellular carcinomas (PHCs) is given. This is followed by a detailed survey of the electron microscopic findings concerning the cytoplasmic inclusions, cell junction structures and hepatitis B virus components seen in the PHC cells. Then the ultrastructural features of certain newly recognized subtypes (fibrolamellar, clear-cell types and primary endocrine liver tumor) of PHCs are described. Finally the importance of electron microscopy in the differential diagnostics of the liver tumors and its contribution to our knowledge concerning the morphology and etiopathogenesis of the PHCs are emphasized.

Bile Canaliculi↗
PubMed1988

[Electron microscopic immunohistochemistry in the diagnosis of human lymphotropic viral diseases].

Immunohistochemistry is finding an ever increasing application for electron microscopic diagnosis of human viral diseases. Certain progress has been made in the use of peroxidase-DAB/OsO4 as an electron-dense marker, and colloid gold. The paper discusses immunohistochemistry application for electron microscopic detection of such lymphotropic viruses as VSV (virus of vesicular stomatitis cultured in mink's lung cells), HTLV-1 (virus of human T4-cell C91Pl lymphoma culture) and HTLV-III/HIV-1 (virus growing in human T4-cell H9 culture).

Acquired Immunodeficiency Syndrome↗
PubMed1988

Glycosaminoglycan containing fat-storing cells in hepatic fibrogenesis.

Male F-344 rats were treated for 10 weeks either with CCl4 (0.2 ml/kg, per os, twice a week) or with CCl4 (same as above) and phenobarbital (0.2 g/l in drinking water). Liver fibrosis and cirrhosis developed in both treated groups, and was confirmed histologically. Cirrhosis was more frequent after the CCl4 + phenobarbital treatment. The collagen content of the liver, measured by morphometry and biochemically, was significantly higher in the animals of the group treated with CCl4 + phenobarbital than in the animals treated only with CCl4. Specially altered fat-storing cells (Ito cells) were found in the periportal and septal fibrotic areas in direct proportion to the amount of fibrosis and cirrhosis. They were identified as altered fat-storing cells by their desmin content and Vitamin A storing capability. This study demonstrated that these cells were enlarged and contained neutral fat, lipofuscin and PAS-positive material. The potential role of GAG-containing FSC in fibrogenesis is discussed.

Animals↗
PubMed1988

Phenotypic characteristics of three human non-Hodgkin lymphoma lines: flow cytometric analysis after long-term maintenance.

Three human non-Hodgkin lymphomas of B-cell origin have been maintained as xenografts in artificially immunosuppressed mice. The long-term maintenance (3-5 years) resulted in no significant change in the morphology, DNA-index or cell surface markers of the tumors. Immunophenotyping revealed many similarities in the morphologically distinct lines. Light chain (lambda) restriction appeared in two lines (HT 58 and 130), but in the third line (HT 117) the co-expression of both light chains indicated the origin from light chain 'uncommitted' B cells. HT 117 was also different, expressing high transferrin-receptor activity, although it proliferates with practically the same rate as the other two lines. This study confirms the value of the xenograft system to approaching many tumor-specific problems.

Animals↗
PubMed1988

Life expectancy in chronic liver disease.

Life-table analysis is a suitable method for evaluating the effectiveness of therapeutical approaches to and the progression of, chronic diseases. The authors performed 324 liver biopsies in patients with liver disease between 1976 and 1986. The cumulative life-table analysis of Cutler and Ederer was applied in this retrospective study. Survival rates of different groups of patients expressed as the 7-year life expectancy were as follows: toxic hepatitis 90%, steatosis hepatitis 87%, chronic persistent hepatitis 87%, nonspecific reactive hepatitis 76%, chronic active hepatitis 72%, acute alcoholic hepatitis 66%, liver cirrhosis 40%. There seems to be a correlation between the severity of histological alteration and live expectancy. A similar correlation between the inflammatory cell infiltration and life expectancy cannot be observed. The life expectancy of patients with chronic active hepatitis has significantly improved recently. Further improvement of survival of patients with liver cirrhosis can be expected only from a reduction of alcohol consumption. The results can be regarded as a reference data for life expectancy of patients with chronic liver disease in Hungary.

Biopsy↗
PubMed1987

Chemotherapeutic response of squamous cell carcinoma xenografts (subcutaneous and subrenal capsule assay).

Chemotherapeutic response of two squamous cell carcinoma xenograft lines (established from the primary and metastatic lesion of a tongue carcinoma) was studied using SC and SRC assays (as well as immunocompetent and -suppressed recipients in the latter assay). The two assays provided similar ranking of drugs, in the sense that in each instances two of the three (cyclophosphamide, 5-fluorouracil, vinblastine) most active agents were identical. The host response in immunocompetent recipients supports the need for histology to prove the proper quality of the implanted tumor tissue in order to be used for drug evaluation.

Aged↗
PubMed1987

The effect of thymopoietin 32-34 (TP3) on suramin-induced inhibition on delayed type hypersensitivity in guinea pigs.

Suramin administration inhibits virus replication and produces impaired immunoregulation. Delayed type hypersensitivity (DTH)-reaction was inhibited by Suramin (200 mg/kg, i.p.) injection in guinea-pigs immunized with BCG vaccine. Suramin-inhibited DTH-reaction was restored to normal level after 4 days of treatment with thymopoietin 32-34 (TP 3) and TP5 (1 mg/kg, i.p.), TP3 greater than TP5. TP3 produced the strongest restoration when applied together with Suramin, but a single treatment with TP3 or TP5 oligopeptide inhibited the development of DTH-reaction. TP3 with Suramin treatment might be advantageous to eliminate defective side effects of Suramin on immune system and TP3 with indirect inducing action on IL-2, IFN-gamma production may be useful in therapy of AIDS patients.

Animals↗
PubMed1987

Immunoregulating peptides II. In vitro effects of TP5 analogs on E-rosette formation and cell division.

The effects of seventeen synthetic analogs of thymopentin (TP-5) have been studied in the active and azathioprine-inhibited E-rosette tests. Thymopentin was gradually shortened from the C terminus to peptides and single amino acids. Thymopoietin 32-34 (Arg-Lys-Asp-RGH-0205-TP-3) (II) and thymopoietin 32-35 (Arg-Lys-Asp-Val-RGH-0206-TP-4) (I) were the most active peptides. Dipeptide Arg-Lys produced significant stimulatory effect on azathioprine (ED75) inhibited E-receptor. Treatment of azathioprine (ED75)-inhibited E-rosette forming cells (ERFC) with arginine or especially lysine increased the number of ERFC. Some of TP-4 analogs decreased further the number of ERFC decreased by azathioprine ED30. These "suppressive" peptides as well as TP-3 caused a partial arrest of K 562 cell proliferation up to 96 hours. Results suggest that TP-5 is not the smallest active fragment of thymopoietins, since peptides (TP-3 and TP-4) exhibit similar or higher T-cell membrane activation on E-receptor. Arginine, lysine, and acidic aspartyl residue seem to be a necessary basic structure to produce a cumulative chemical signal on the activity of T-lymphocytes.

Adjuvants, Immunologic↗