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Biomedical subjects

T Michalak

Publications and source records attributed to T Michalak.

At least 19 recordsLinked to original sources
PubMed1993

[Laparoscopic cholecystectomy--treatment outcome of 500 patients].

500 patients with symptomatic biliary stones disease have been treated by laparoscopic cholecystectomy (LCh). Contraindications, such as: acute inflammation, earlier laparotomies, common duct stones or obesity were considered as relatives. In cases with duct stones, ERCP with sphincterotomy and evacuation of duct stones was performed before LCh. Small percentage of LCh failures (2.6%) and of postoperative morbidity (3.4%) by undoubted advantages as: lack of postoperative paresis of digestive tract, reduced inability time for professional activity and low risk of postoperative abdominal hernia make this procedure attractive for patients and surgeons.

Adolescent↗
PubMed1993

[Results of treating inflammatory aneurysms of the abdominal aorta].

The authors present the results of treatment of six inflammatory aneurysms in the material of 53 aneurysms treated surgically in the years 1987-1992. Direct results of surgical treatment, hospitalization period, and peri-operational complications are the subject of analysis. Peri-operational mortality of the patients with inflammatory aneurysm was higher than that of patients with non-inflammatory aneurysm, undergoing elective surgery. Higher incidence of peri-operational complications indicates higher operational risk of inflammatory aneurysm.

Adult↗
PubMed1986

A monoclonal antibody to the endothelium of rat brain microvessels.

A rat brain fraction enriched with microvessels was used as the immunogen to produce mouse hybridoma cell lines secreting monoclonal antibodies. One of these antibodies, selected from 156 supernatants by enzyme-linked immunosorbent and immunofluorescent assays, reacted only with the endothelium of microvessels in the brain. The endothelium-specific antibody labelled the cytoplasm of microvascular endothelial cells, their luminal membranes, and an extracellular layer, the endocapillary coat, which covered the luminal surface of these cells. In the kidney, the antibody specifically stained the brush border of the proximal tubuli, and in the liver, the antibody specifically stained bile canaliculi. This demonstrates that 3 morphological structures with important transport functions, cerebral microvascular endothelium, brush border of kidney proximal tubuli, and liver bile canaliculi, express the same epitope.

Animals↗
PubMed1984

The function and morphology of the liver in porphyria cutanea tarda.

The aminopyrine breath test, postprandial serum bile acids, and routine liver tests were assessed as indicators of liver dysfunction in 38 patients with porphyria cutanea tarda. In 17 patients needle biopsy specimens of the liver were obtained. Bile acids were increased in almost all the patients studied (97%) but impairment of aminopyrine demethylation was found in only 45%. More than 50% of cases had elevated activities of serum alanine aminopeptidase, leucine aminopeptidase, gammaglutamyl transpeptidase (GGTP), and alanine aminotransferase (ALAT). All liver biopsy specimens showed fluorescence characteristic of porphyrins. Histologic examination of biopsy material revealed cellular lesions in all cases, the most common pathological findings being fatty degeneration of varying degree and iron accumulation. The most frequent electronmicroscopic changes in the liver were fat droplets, granules containing bile material, and siderosomes in the cytoplasm of hepatocytes. However, there was no evident relationship between morphological and functional liver changes.

Adult↗
PubMed1983

Abnormalities in liver function and morphology and impaired aminopyrine metabolism in hereditary hepatic porphyrias.

The aminopyrine breath test and measurement of postprandial serum bile acids were performed in 67 patients with well-documented hereditary hepatic porphyria. Elevated postprandial serum bile acids levels were found in 75% and the aminopyrine breath test was abnormal in 42% of the patients studied. These function tests exhibited a statistically significant correlation with the excretion of porphyrin precursors in patients with acute intermittent porphyria. Furthermore, all 12 patients with acute intermittent porphyria who had a liver biopsy because of abnormalities in the aminopyrine breath test or postprandial serum bile acids measurement, or both, were found to have diffuse, moderately severe, but nonspecific ultrastructural changes of hepatocytes, indicative of significant subcellular damage. While a direct relationship between functional and morphologic abnormalities is speculative, it is possible that the defective heme biosynthesis, perhaps related to the reduced aminopyrine demethylation, could form the basis for the ultrastructural hepatic changes in porphyria. This, in turn, could be the cause of the elevated postprandial serum bile acids levels.

Adult↗
PubMed1983

Localization of carcinoembryonic antigen in mesenteric lymph nodes of patients with gastrointestinal cancer.

Mesenteric lymph nodes obtained at surgery from 36 patients with gastrointestinal tract cancer were studied by immunofluorescence for the presence of carcinoembryonic antigen (CEA). Granular deposits of CEA in a homogenous mixture with immunoglobulins and complement were detected in the activated germinal centers in 12 lymph nodes from 8 investigated cases. Identification of CEA in germinal centers was confirmed by blocking and absorbtion procedures. Successful elution of immunoglobulins and part of CEA content with a buffer known to dissociate antigen-antibody bonds suggested that these deposits represent CEA immune complexes.

Adenocarcinoma↗
PubMed1982

Crystalline aggregates of hepatitis B core particles in cytoplasm of hepatocytes.

Large crystalline accumulations of hepatitis B core antigen (HBcAg) particles were detected in the cytoplasm of hepatocytes from a patient with mild reactive hepatitis. Within these crystals, the core particles showed a symmetrical hexagonal arrangement with the center-to-center particle distance estimated at 24 nm. The possible mechanism of aggregation and the significance of HBcAg crystalline lattice in the preservation of hepatitis B virus are discussed.

Carrier State↗
PubMed1981

Attempts at detection of actomyosin associated with influenza virus.

Influenza virus strans A/Scotland/74, A/Hong Kong/68, A/Port Chalmers/73 and the MRC-12 recombinant were tested with immune antiserum against actomyosin. As shown by electron microscopy, the serum aggregated virus particles, but only after bromelain treatment (without haemagglutinin and neuraminidase spikes). In rocket electrophoresis the serum gave positive precipitation reaction with all the strains tested, and with virus from various hosts (chick embryo, monkey kidney cell culture, mice after adaptation). There fore the host protein presumably is present in the influenza virus structure irrespective of the strain or the host in which the virus is grown.

Actomyosin↗
PubMed1980

Hepatitis B surface antigen and albumin in human hepatocytes. An immunofluorescent and immunoelectron microscopic study.

A close correlation between the presence of hepatitis B surface antigen and albumin in the cytoplasm of hepatocytes infected with hepatitis B virus was established by immunofluorescence and immunoelectron microscopy in 52 liver biopsy specimens of various forms of hepatitis and liver cirrhosis. Albumin deposits usually accompanied cytoplasmic content of hepatitis B surface antigen, but were less frequently observed together with hepatitis B antigen localized in or on the membranes. Ultrastructural observations demonstrated albumin on the tubular and spherical forms of hepatitis B surface antigen in the endoplasmic reticulum. The hepatocytes with the content of hepatitis B surface antigen and albumin showed the ability of binding with the fluorescein-labeled preparation of polymerized human serum albumin. The affinity of polymerized albumin to hepatitis B surface antigen was considerably increased after preincubuation of liver sections with 2-mercaptoethanol that removed most of the originally present albumin. This may be indicative for the role of disulfide bonds in the formation of hepatitis B surface antigen-albumin complexes. These results justify the hypothesis that albumin may be incorporated into the viral coat protein during its synthesis in the cytoplasm of infected hepatocytes.

Acute Disease↗
PubMed1980

Membranous glomerulopathy associated with hepatitis B core antigen immune complexes in children.

Direct immunofluorescence, immunoelectron microscopy, and special immunohistochemical procedures including guinea pig complement fixation, differential elution, and in situ antigen binding were employed in an immunomorphologic analysis of kidney biopsy specimens from 98 children with clinically diagnosed nephrotic syndrome and/or glomerulonephritis (GN). Glomerular deposits of hepatitis B virus (HBV) antigens, immunoglobulins, and complement were detected in specimens from 24 children, all seropositive for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen (HBcAg). Of these, 21 cases were diagnosed as membranous glomerulopathy (MGN), 1 as membranoproliferative GN, and 2 as diffuse mesangial proliferative GN. HBaAg was identified as the only HBV antigen in about a third of the cases of MGN, whereas in another third it was accompanied by HBsAg. HBsAg was the only HBV antigenic component detected in the glomerular deposits in the remaining third of the cases of this GN form. The results of this study indicate that apart from, or in addition to, HBsAg immune complexes, HBcAg immune complexes may also participate in the pathogenesis of a significant number of MGN cases in children subclinically infected with HBV. A possibility that these complexes include nonparticulate, presumably low-molecular-weight HBaAg components and that they are found in an environment of antibody-excess is discussed.

Adolescent↗
PubMed1979

Autoantibodies in human sera after vaccination with inactivated influenza vaccine.

Sera from persons vaccinated with inactivated bivalent influenza vaccine were tested for the presence of smooth-muscle antibodies (SMA) and antibodies against the brush border of proximal renal tubuli (ABBA). The autoantibodies were found with the highest frequency in persons repeatedly vaccinated with the vaccine.

Antibodies, Viral↗
PubMed1978

Immune complexes of hepatitis B surface antigen in the pathogenesis of periarteritis nodosa. A study of seven necropsy cases.

In 7 unselected necropsy cases of clinically diagnosed periarteritis nodosa, the detection of hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) in the cytoplasm and nuclei of hepatocytes indicated an ongoing infection with hepititis B virus (HBV). In all these cases histologic changes found in the liver varied from "minimal" to chronic aggressive hepatitis. In all the cases, deposits of HBsAg, immunoglobulins, beta1C-globulin and C1q were detected in vascular lesions. That these deposits could represent HBsAg-anti-HBs immune complexes was supported by demonstrating their strong binding of guinea pig complement and by the successful elution of all HBsAg and part of the immunoglobulin from these deposits by treatment with buffers known to dissociate antigen-antibody bonds but not with phosphate-buffered saline, pH 7.6 (PBS). Glomerulonephritis associated with these immune complexes was found in 6 cases. The presence of larger masses of HBsAg immune complexes, chiefly in recent insudative and fibrinoid vascular lesions, their lesser amounts in lesions undergoing involution, and their absence from healed lesions strongly suggest that these complexes play a primary role in the pathogenesis of acute vascular damage in periarteritis nodosa.

Adult↗