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Biomedical subjects

J Sipos

Publications and source records attributed to J Sipos.

At least 19 recordsLinked to original sources
PubMed1992

Synthesis and gastroprotective activity of 4H-pyrido[1,2-a]pyrimidin-4-ones.

The cytoprotective effect of different types of 4h-pyrido[1,2-a]pyrimidin-4-one derivatives was investigated. Short synthesis of the investigated compounds was depicted. The gastroprotective effect was determined against acidified ethanol induced mucosal lesions in rats. The most effective compounds belong to unsaturated 4-oxo-4h-pyrido[1,2-a]pyrimidine-3-carboxamide derivatives, and the most active one contains a methyl group in position 6 and a cyclopentyl group on the nitrogen of the carboxamide group. Further pharmacological, biochemical and clinical studies may justify, that the representative of this type of compounds may be useful as prophylactic agents against gastric damage caused by non-steroidal antiinflammatory agents.

Animals↗
PubMed1990

[Subscapular liver hematoma and liver hemorrhage in neonatal age].

By analysing their newborn patients of 15 years the authors confirm the earlier observation, that the subcapsular haematoma is a common finding at postmortem examination of the newborns dying during neonatal period. The association of the pathological symptoms of hypoxic origin of the other organs observed at autopsy and the decreasing incidence of subcapsular haematoma as a results of obstetrical and neonatal intensive care make this disease of hypoxic origin probable. In spite of common subcapsular haematoma the haemorrhage of liver causing haemascos is relatively uncommon. In their five patients suffering from liver rupture they observed two types of this (immediate and delayed rupture of liver's capsule), which also differed from one another in their clinical picture. They are drawing attention to general use of ultrasound in diagnostics which means a new chance to diagnosis in alive of both types.

Hematoma↗
PubMed1990

Antibodies against the hepatic asialoglycoprotein receptor perfused in situ preferentially attach to periportal liver cells in the rat.

Autoantibodies reacting with the galactose-specific hepatic asialoglycoprotein receptor--a liver-specific component expressed on the surfaces of hepatocytes--are often found in patients with chronic active hepatitis of presumed autoimmune origin. As part of an investigation into whether these anti-asialoglycoprotein receptor antibodies might be involved in the development of periportal liver damage in chronic active hepatitis, livers of ether-anesthetized rats were perfused in situ with polyclonal guinea pig anti-rabbit asialoglycoprotein receptor or murine monoclonal anti-human galactose-specific hepatic asialoglycoprotein receptor antibodies in excess at less than 8 degrees C or, as a control, with guinea pig anti-human plasma protein antibodies or normal guinea pig serum. Rapid (1 min) antegrade (by way of portal vein) or retrograde (through hepatic veins by way of vena cava) perfusions were performed in a nonrecirculating (once-through) mode in Ca+(+)-free medium. Blocks of liver tissue were immediately snap-frozen and the distribution of the antibody examined in cryostat sections by using an avidin-biotin immunohistochemical technique. In all of the perfusions with anti-asialoglycoprotein receptor (six antegrade, seven retrograde), the antibodies were found to be prominently and almost exclusively deposited on liver cells in the periportal areas. No deposition of immunoglobulins was detected in livers perfused with the control guinea pig sera. The findings suggest that the asialoglycoprotein receptor is expressed at high density mainly on cells in zone 1 of the hepatic lobule, and this may have implications for the development of periportal liver damage in chronic active hepatitis.

Animals↗
PubMed1989

Immunohistochemical demonstration of the asialoglycoprotein receptor in rat liver by a sensitive avidin-biotin technique.

An immunohistochemical technique for the detection of the hepatic asialoglycoprotein receptor (ASGP-R) in cryostat sections of liver by polyclonal and monoclonal anti-ASGP-R antibodies is described. The procedure is based on the alkaline-phosphatase-avidin-biotin complex (ABC-AP) system and important features include fixation of the sections with periodate-lysine-paraformaldehyde (with or without dichromate) and an absolute requirement for blocking of endogenous biotin activity. The sensitivity of the technique is such that binding to ASGP-R can be detected with femtomolar concentrations of monoclonal anti-ASGP-R antibodies and, with polyclonal antisera, approaches that of a radioimmunoassay.

Animals↗
PubMed1988

Sensitive avidin biotin based technique for identifying liver membrane antigens in tissue sections.

An enzyme immunohistochemical technique for the localisation of liver membrane antigens in tissue sections by antisera raised in guinea pigs against the liver preparation known as "liver specific membrane lipoprotein (LSP)" was developed, based on the alkaline phosphatase avidin biotin complex (ABC AP) system. Of a wide range of fixatives and fixation conditions investigated, a short (five minute) exposure of cryostat sections to Bouin's fluid provided the most satisfactory results and--together with procedures to block endogenous biotin and alkaline phosphatase--yielded clear sections with no background staining or other artefacts to interfere with specific staining patterns. The sensitivity of the technique approaches that of a radioimmunoassay, as shown by the staining of the sinusoidal domains of hepatocellular plasma membranes by the guinea pig anti-LSP antisera at dilutions up to 1/50,000. Apart from its reliability and sensitivity the procedure offers additional advantages over techniques such as indirect immunofluorescence in that it provides a permanent preparation with well defined morphological details which can be seen by ordinary light microscopy.

Animals↗
PubMed1984

Effect of (+)-cyanidanol-3 on receptor activity of lymphocytes and hepatocytes and on hepatocyte-lymphocyte conjugation in alcoholic liver disease.

The recirculation of lymphocytes and cell-mediated immunity show profound alterations in alcoholic liver disease. The use of cianidanol corrects a lot of these disturbances, in that: a) it can modify the receptor avidity of hepatocytes, b) it reduces the cell-mediated immune reactivity against liver specific protein antigen, diminishing the auto-immune reactions in alcoholic liver disease, c) it has no effect upon the conjugation process between the hepatocytes as target cells and cytotoxic effector cells, d) it decreases, however, the number of hepatocytes damaged after the conjugation process, and e) as a potent free-radical scavenger, it inhibits the cytotoxic effect of natural killer cells and monocytes, and in the same manner prevents the alteration of the hepatocyte membrane.

Adult↗
PubMed1981

Investigations on blood and cerebrospinal fluid lymphocytes in patients suffering from tick-borne encephalitis.

This paper deals with the immuno-pathological characteristics of tick-borne encephalitis. With the appearance of neurological signs, there is a strong T cell reaction in th peripheral blood. The following seven days are characterized by the appearance of specific cell-mediated reaction in the peripheral blood; in the cell-mediated reaction in the peripheral blood; in the cerebrospinal fluid, an increasing number of B cells and specific antibodies can be detected. After a week, the percent positivity of cell-mediated immune reactions is higher and there is a T cell dominance in the cerebrospinal fluid. Intact cellular immunity against specific antigen is required for the management of this disease. There are major differences in the results obtained from patients suffering from meningitis alone and those suffering from meningoencephalitis.

B-Lymphocytes↗
PubMed1978

Inhibition of leukocyte migration by tumor-associated antigen and its modification by serum; IgA as a blocking factor.

Based on the investigations of patients the migration inhibition assay proved to be a useful method for the detection of antitumorous cellular immunity. Out of the twenty patients tested 15 gave migratory inhibitory effect against specific tumor antigen. In 8 cases out of the above 15 the blocking activity of sera has been proved. This blocking activity is bound to IgA subclass. The complement played an "unblocking" role. The modifying role of serum factors in cellular immunity against tumors was discussed.

Antigen-Antibody Complex↗