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Biomedical subjects

D A Levison

Publications and source records attributed to D A Levison.

122 records · Page 7Linked to original sources

Oesophageal neoplasia in male Wistar rats due to parenteral di(2-hydroxypropyl)-Nitrosamine (DHPN): a combined histopathological, histochemical and electron microscopic study.

Intraperitoneal di(2-hydroxypropyl)-Nitrosamine (DHPN) caused a high incidence of oesophageal squamous carcinoma in male Wistar rats, particularly in rats killed 11 or more months after the start of injections. No control rats (injected intraperitoneally with saline) developed an oesophageal neoplasms. Histopathologically, the tumours were moderately well differentiated. Histochemical studies showed minor increases in mucin staining and mast cell population and a marked increase in bacteria in tumour-bearing oesophaguses. Electron microscopy showed the tumours to be similar to, but to differ in some respects from squamous carcinomas at other sites in humans. The possible implications of this work for human disease are twofold. It could provide a model for further study of aspects of oesophageal carcinoma and it serves to remind us that all potential oesophageal carcinogens need not act during swallowing.

Animals↗

An ultrastructural study of osmiophilia in the human rectum.

Rectal biopsies from subjects with a normal rectum and from patients with various forms of inflammatory bowel disease were studied by the prolonged osmication technique. No consistent ultrastructural differences were observed between these groups, but there were striking differences between individual epithelial cells in the same biopsy and between the epithelium and the cells of the lamina propria. The Golgi apparatus was demonstrated occasionally in the epithelium, often in endothelium. Endoplasmic reticulum, perinuclear cisterna and mitochondria were variably outlined. In plasma cells, there were striking differences in osmiophilia. The underlying mechanism of the different staining patterns is not clear. The findings do not appear to help in the differential diagnosis of inflammatory bowel disease nor to shed any new light on their underlying pathogenic mechanisms.

Cell Membrane↗

Problem solving cases in teaching of applied pathology.

A "problem solving case" method of teaching practical pathology is described, illustrated and compared with more traditional teaching methods. This method offers many advantages-the most important being that it shows the effect of pathological lesions in an actual patient, thus emphasizing the relevance of pathology to clinical medicine. Other advantages are that self-assessmetn is encouraged; guidance is given on the depth of knowledge expected from a student; student response is favourable; no elaborate or expensive equipment is required; the method is economic in the use of staff time, and it is very flexible in use in terms both of time and place.

Autopsy↗

Intercellular spaces and cell junctions in endometrial glands: their possible role in menstruation.

Intercellular spaces and cell junctions in human endometrial glands were studied by elctron microscopy following different methods of fixation. The size of the spaces, known to alter during the cycle, was found to depend also on the method of fixation. Various intrusive cells and different types of cell debris were seen in these spaces. The three most widely recognized cell junctions (desmosomes, tight junctions and gap junctions), were all most abundant near the cell apices. The possible significance of these findings in elucidating the cellular mechanism of menstruation is discussed.

Endometrium↗

Atrophy and apoptosis in the cyclical human endometrium.

Electron microscopy of human cyclical endometrium indicates that there is considerable loss of gland epithelial cells with formation of apoptotic bodies in the late secretory, premenstrual and menstrual phases, but also to a lesser extent in the proliferative phase. Apoptotic bodies containing nuclear fragments may be recognised on light microscopy as basophilic or Feulgen positive granules. These granules accumulate in greatest numbers towards the end of the cycle and may be used as an additional aid in dating curettings.

Atrophy↗

Clinicopathological spectrum of late postpartum renal failure; two contrasting cases.

The clinical and renal biopsy findings from two patients in whom renal functional abnormalities developed in the late postpartum period are described. Both biopsies showed fibrin deposition in the renal vasculature, in one case marked and in the other mild. The patient with the more severely damaged kidney subsequently died, and the other is alive but with evidence of slowly progressing renal damage. The clinicopathological spectrum and pathogenesis of late postpartum renal failure are discussed.

Acute Kidney Injury↗

Primary cardiac Kaposi's sarcoma.

We report the clinical, laboratory, and necropsy findings in a 14-year-old boy with a primary Kaposi's sarcoma of the heart. Primary cardiac Kaposi's sarcoma and angiosarcoma are compared, and the pathogenesis of Kaposi's sarcoma is discussed. Relevant literature is briefly reviewed.

Adolescent↗

Angiotropic large cell lymphoma (ALCL): morphological, immunohistochemical and genotypic studies with analysis of previous reports.

The entity 'angioendotheliomatosis proliferans systemisata' was first described 28 years ago as a cutaneous small vessel neoplasm of presumed endothelial origin. Since then, 101 similar cases have been reported under a variety of different names, most with systemic as well as cutaneous lesions, and a lymphoid histogenesis of the tumour cell is now favoured. Review of these cases has shown a characteristic clinical presentation with predominant neurological and dermatological features, although the diagnosis was made at autopsy in 53 per cent of patients. Most therapeutic regimens have proved ineffective with a median survival of 5 months from date of clinical presentation. Aggressive combination chemotherapy can produce complete and lasting remission and a partial response to steroids is sometimes seen. We have examined a case of this condition showing unusual clinical features. Immunohistochemical studies confirm the lymphoid origin of the tumour cells with B cell phenotype. Antigen receptor gene rearrangement studies indicate the presence of the same clonal population of B cells in multiple sites. We suggest that the term 'angioendotheliomatosis proliferans systemisata' should be dropped and support the use of 'angiotropic large cell lymphoma' to describe this unusual condition.

B-Lymphocytes↗