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Biomedical subjects

A Balaton

Publications and source records attributed to A Balaton.

24 records · Page 2Linked to original sources

Surface healing and histologic maturation of patent polytetrafluoroethylene grafts implanted in patients for up to 60 months.

Histologic, transmission, and scanning electron microscopic observations were made of 26 biopsy specimens from patent polytetrafluoroethylene grafts that had been implanted as arterial bypasses for up to 60 months. The results showed the rarity of host connective tissue ingrowth, the absence of neovascularization, and the limited neointimal proliferation. The defect of staining for factor VIII-related antigen by immunohistochemistry confirmed the absence of true endothelial cells at a distance from the anastomoses. Under electron microscopy the thin neointimal layer consisted mainly of fibrin, platelets, blood cells, and cellular debris. Even in prostheses implanted for the longest periods, mature collagen and elastin were not found. Tubular microfibrils (9- to 12-nm thick) could be observed. The source of such microfibrils, probably glycoproteins, remains under investigation.

Adult↗

Production of monoclonal antibodies to the high fibrin-affinity, tissue-type plasminogen activator of human plasma. Demonstration of its endothelial origin by immunolocalization.

Monoclonal antibodies (MAbs) to vascular plasminogen activator (vPA), the tissue-type plasminogen activator (tPA) in human plasma, were produced to be used as probes for immunochemical analysis. Human tissue sections and one of these MAbs were used to demonstrate the endothelial origin of plasma-tPA by immunohistochemistry. To produce MAbs, mice were immunized with semipurified vPA isolated from postocclusion human venous blood. Primed spleen cells were fused with the mouse myeloma cell line NS-1. Screening for MAb-producing hybridomas was performed with postocclusion euglobulins as a source of antigen by means of a solid-phase fibrin-vPA immunoassay. The selective and high-affinity binding of vPA for fibrin ensures the specificity and sensitivity of this test. Thus, eight hybridomas secreting MAbs to vPA were selected, cloned, and established as permanent hybridoma cell lines. Immunohistochemical analysis of cryostat sections of human tissues was performed with EA-delta 12D, a MAb having no inhibitory effect against vPA activity but binding to vPA with a high affinity. Thus, the only structures immunostained were endothelial cells of venules, capillaries, and arterioles. The EA-delta 12D monoclonal localization of plasma vPA in the endothelial lining of blood vessels provides evidence that tPA in plasma originates from the vascular wall and validates its designation as vascular plasminogen activator, ie, vPA. Also, our results are consistent with the fact that vPA in blood and tPA in tissues are immunologically identical and have a common endothelial origin.

Antibodies, Monoclonal↗

[Myenteric plexuses and colonic diverticulosis: results of a histological study].

The implication of intraluminal hyperpressure in the pathogenesis of colonic diverticulosis was investigated. Since colonic motricity depends on the anatomical integrity of the myenteric plexuses, we looked for morphological abnormalities of these plexuses in diverticulosis of the sigmoid, using the silver impregnation technique devised by Smith. Fifteen sigmoidectomy specimens (including the rectosigmoid junction) were studied in patients afflicted with diverticulosis. Operations were not performed during the acute phases of the illness. The results were compared to those obtained in 5 colectomy specimens in patients with cancer of the rectum, without colonic diverticulosis (control series). Conventional histology as well as the silver impregnation did not reveal any morphological abnormalities of the myenteric plexuses in the rectosigmoid junction or in the remaining sigmoid. The count of argyrophilic ganglion cells (10 to 15 per plexus) was identical in the colons affected with diverticulosis and in the control specimens. These results show that impairment of motricity in sigmoid diverticulosis is not a consequence of morphological abnormalities of the myenteric plexuses. They do not, however, exclude chemical or functional modifications in these plexuses.

Aged↗

[Fibromyolipoma of the uterus. Apropos of a case with a review of the medical literature].

A case of uterine fibromyolipoma in a 75 year old woman suffering from an uterine prolapse is reported. The clinical course, the macroscopic and microscopic characteristics are presented and compared with those in the medical literature. The possible histogenesis is discussed. Our case seems to results from metamorphosis of uterine smooth muscle cells in a leiomyoma.

Aged↗

[Giant colonic or ileo-jejunal diverticulum and infra-mesocolic abdomial pseudocysts: diagnosis, pathalogical and clinical analysis].

Giant diverticula of the small intestine and colon are rare. Four cases treated at our institution in the last year are reported and compared to published cases; specific features and those which differentiate them from abdominal pseudocysts are described. They most commonly present a clinical tableau similar to commonplace diverticular disease. Awareness of this unusual condition and a good CT study are the keys to diagnosis. Giant diverticula may be acquired or congenital. The acquired type is simply a more spectacular version of commonplace diverticulosis while the congenital type, having a muscular wall and myenteric plexus, is more akin to intestinal duplications. Treatment is surgical and, in the case of sigmoid giant diverticula, usually requires a colon resection similar to that required for sigmoid diverticulitis.

Aged↗

Adult-type rhabdomyoma of the palate. Cytologic presentation of two cases with histologic and immunologic study.

The cytologic presentations of two adult-type rhabdomyomas of the soft palate are reported. Fine needle aspiration smears of the lesions contained globular tumor cells that had striations and intracytoplasmic rod-shaped inclusions. These inclusions, corresponding to hypertrophied Z bands, were pathognomonic of rhabdomyoma tissue. The cytologic diagnosis was confirmed by histologic and immunologic studies in both cases. The cytologic preparations fixed in alcohol or air dried did not show the "spiderweb cells" observed in the histologic sections of tissue fragments fixed in formaldehyde; this clearly illustrates that the morphology of the cells of this tumor depends primarily on the specimen preparation technique used. These cases suggest that aspiration cytology can establish the diagnosis of this benign tumor of striated muscle, for which total surgical removal is usually sufficient to effect a cure. The differential diagnosis is discussed in detail.

Adult↗