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Biomedical subjects

V Desmet

Publications and source records attributed to V Desmet.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Are nuclear particles specific for non-A, non-B hepatitis?

This study reports the findings of an electron microscopic search for so-called non-A, non-B nuclear particles in liver biopsies from patients with mainly chronic or prolonged liver disease and from chimpanzees. In patients without hepatitis B virus or acute hepatitis A virus serological markers, non-A, non-B-like nuclear particles were seen in hepatocytes in 28 of 31 cases of presumed non-A, non-B hepatitis, but also in 11 of 12 cases of liver disease not usually attributed to hepatitis viruses. They were also seen in 22 of 24 patients with HBsAg, in 3 of 3 patients with anti-HBc and no HBsAg, in 1 of 2 patients with hepatitis A, in a case of cytomegalovirus hepatitis, and in 16 of 19 patients whose serology was not available or inconclusive. The particles were present in 1 of 8 untreated HBsAg-negative chimpanzees and in 2 of 2 HBsAg-positive chimpanzees. They appeared in 4 of 4 chimpanzees developing non-A, non-B hepatitis following exposure to various inocula. Three patterns of particle aggregates were distinguished, all of which had been shown by others in non-A, non-B hepatitis. Dense aggregates were predominant, while others have shown intermediate aggregates more often; reasons for this difference could be technical. No pattern was specific for any condition. Either non-A, non-B-like nuclear particles, although associated with non-A, non-B hepatitis, are not specific for this condition, or non-A, non-B hepatitis viruses are extremely more common than is currently appreciated.

Animals↗
PubMedDate not supplied

Ultrastructural immunocytochemical demonstration of HLA class I antigens in human pathological liver tissue.

Major histocompatibility complex products Class I (HLA Class I) antigens are not expressed on the surface of normal human hepatocytes but become so in pathological conditions. The purpose of this study was to specify the ultrastructural topography of HLA Class I antigens expression. Nine human liver specimens, known from light microscopic investigation to display membranous positivity for HLA Class I antigens, were processed for immunoelectronmicroscopy using monoclonal anti-HLA Class I in an indirect immunoperoxidase procedure. HLA Class I antigens were detected on the basolateral membrane of hepatocytes and bile duct cells; some cisternae of the endoplasmic reticulum were also positive. The membranes of normal bile canaliculi of hepatocytes and the apical border of bile duct cells were negative. In one case of presumably drug-induced cholestasis, abnormal cholestatic canaliculi displayed HLA Class I antigens. These results indicate that HLA Class I antigens are synthesized by the hepatocytes and bile duct cells and incorporated into the plasma membrane; the basolateral expression follows the pattern as in other polarized cells. The expression in cholestatic canaliculi suggests a disturbed polarity of the hepatocyte.

Bile Ducts↗
PubMedDate not supplied

Whipple's disease: endoscopic aspects before and after therapy.

This report describes the utility and the advantages of endoscopy in diagnosing and following the course of Whipple's disease. Sixteen patients, diagnosed over a period of 22 years, were identified via pathology records and retrospectively reviewed. Five patients were diagnosed before 1980 by means of peroral suction biopsy of the small intestine. The 11 patients diagnosed after 1980 all had upper gastrointestinal endoscopy and endoscopic small intestinal biopsies. Gross endoscopic lesions were observed in 9 of the 11 patients and disappeared in 5 of 6 treated patients at 6 months. These lesions include erosions, yellow plaques, and a pale yellow shaggy mucosa. The latter two lesions are macroscopically suggestive of Whipple's disease. After endoscopic "healing," periodic acid-Schiff-positive macrophages remained present in the endoscopic biopsies for years. The patients were followed for a median period of 4 years and 5 months. All patients were treated with antibiotics (eight tetracycline alone, four tetracycline + streptomycin + penicillin, and four trimethoprim). Five patients (four of the tetracycline alone group, none of the trimethoprim group) relapsed 2 to 11 years after the initial treatment.

Adult↗
PubMedDate not supplied

Plasmacytoid monocytes in epithelioid cell granulomas: ultrastructural and immunoelectron microscopic study.

Plasmacytoid monocytes, the so-called plasmacytoid T cells, were originally described in rare cases of lymphadenitis. Recent immunohistochemical studies have demonstrated their monocytic origin. Plasmacytoid monocytes have in common with epithelioid cells and multinucleated giant cells the expression of several antigens; they also occur in close topographic association with epithelioid and multinucleated giant cells in epithelioid cell granulomas. On the basis of these data it has been suggested that plasmacytoid monocytes may transform into epithelioid cells. The present ultrastructural and immunoelectron microscopic study of epithelioid cell granulomas provides further arguments in favor of this hypothesis. Moreover, the existence of a transitional cell type with characteristics of plasmacytoid monocytes and epithelioid cells is documented. Subplasmalemmal linear densities present on focal areas of the plasma membrane of the main cell components of granulomas are also discussed.

Antigens, Surface↗
PubMedDate not supplied

Study of the usefulness and the limits of ultrasonic diagnostic criteria for diagnosis of liver tumours.

We studied the usefulness and the limits of the ultrasonic diagnostic criteria for liver tumours formulated by the Japan Society of Ultrasonics in Medicine (JSUM). 226 cases with liver mass lesions were enrolled in this study. At least one of the criteria reached a value of over 80% for one of the items: sensitivity, specificity, positive predictive value, negative predictive value or overall accuracy. In the differentiation of liver tumours, sharp & smooth boundary, presence of marginal hypoechoic zone, mosaic pattern, starry anechoic area, posterior echo enhancement and lateral shadows were important for HCC. For metastatic liver cancer, potato shape, coarsely irregular boundary, presence of marginal hypoechoic zone, internal target like anecho were important features. The liver pathology of the false negative cases corresponded to: a) liver tissue completely replaced or infiltrated by HCC or metastasis. b) the non-tumour tissue and tumour tissue were isoechoic but also without marginal hypoechoic zone. c) the ultrasonograms of non tumoural areas were modified by calcification of eggs of schistosomiasis and severe fibrosis. It can be concluded that most HCC and metastatic liver cancers over 3 cm in diameter can be diagnosed correctly by the JSUM's criteria. However, complimentary image diagnosis and fine needle biopsy are important to assure the highest diagnostic score in cases with US negative and small tumours.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Whipple's disease: the value of upper gastrointestinal endoscopy for the diagnosis and follow-up.

Due to the systemic nature of Whipple's disease the clinical presentation may be highly variable. The diagnosis may therefore be unduly delayed. If untreated, Whipple's disease is still potentially lethal. In contrast, the endoscopic findings as they are observed in the postbulbar small intestine and the light microscopic picture of small intestinal biopsies are almost pathognomonic. Out of a group of 18 patients (14 male, 4 female, mean age = 45 yrs), 12 patients were diagnosed using upper gastrointestinal endoscopy and duodenal biopsy, while six patients were diagnosed only by a small intestinal capsule biopsy. The clinical history prior to diagnosis lasted from 1 m to 22 yrs (mean = 3 yrs 6 m) in the first group and from 4 yrs to 21 yrs (mean = 12 yrs 6 m) in the second group. The endoscopic findings at the time of diagnosis were: oesophagitis (1/12), erosive gastritis (4/12), atrophic gastritis (2/12), severe erosive bulbitis (3/10), pathognomonic post-bulbar duodenal lesions (9/12). In 20% of the patients the endoscopic lesions had disappeared 6 m after antibiotics while the lesions had disappeared in all cases 9 m after therapy, despite the fact that PAS positive macrophages remained present in the endoscopic biopsies for years. All patients were treated with antibiotics (8 tetracycline alone, 4 tetracycline, streptomycin and penicillin, 6 trimethoprim). Five patients (27%-4 of the tetracycline group) relapsed within 2 to 20 yrs after the initial diagnosis. Three of these patients (3/5) had typical duodenal lesions on endoscopy at that time.

Adult↗
PubMedDate not supplied

Small bowel amyloidosis, pathology and diagnosis.

The authors describe clinical findings, radiological aspects and histological characteristics of small bowel amyloidosis in 8 patients. Pathogenesis of the small bowel related symptoms and diagnostic procedures are discussed.

Adult↗