Biomedical subjects
Publications and source records attributed to R David.
Pilocarpine 4% solutions at pH 4.1 and 5.8 were compared in a double-blind clinical trial on 24 eyes of patients with primary open-angle glaucoma. Each drug was used over a period of 1 week. No significant difference in the lowering of intraocular pressure was found, and the near-neutral solution of pilocarpine was found to be equally stable when compared to the acid solution over a 6-month period.
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A case is described of Burkitt's lymphoma in a nine-year-old Arab boy. The presenting symptom was swelling of the right maxilla, originally diagnosed as a dento-alveolar abscess. The clinical features of African and American Burkitt's lymphoma are compared, and the occurrence of the tumor mainly in the Arab population of Israel is noted.
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A series of 120 cases of lumbo-sacral arachno-epiduritis was studied from the clinical and etiological points of view. The recruitment of the cases and their classification were based on purely radiological criteria. The clinical symptoms were various, non-specific and without correlation with the radiological type. The course was chronic with a change in the distribution of the symptoms. The influence of the method of examination was discussed in the 9 cases discussed after a first myelography without surgical operation. All the forms suggesting epidural lesions were post-operative and observed mainly in cases of laminectomy.
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We report a 14-year-old boy with severe hypertension who was cured by surgical removal of a pheochromocytoma. The tumor was shown biochemically and morphologically to secrete predominantly noradrenaline. The metabolic effects noted in this patient were raised free fatty acid levels and depressed insulin levels, hyperreninemia, hypercalcemia, and hypercalciuria with normal parathyroid function. All these abnormalities returned to normal after removal of the tumor. It is suggested that these effects were mediated via beta-adrenergic stimulation of the excess noradrenaline.
Sixty patients with non-Hodgkin's lymphomas were treated with a cyclophosphamide, vincristine, and prednisone (CVP) induction regimen, either alone (stage IV) or in combination with radiotherapy (stages I, II, III). The response rates for lymphocytic and histiocytic lymphomas were 82 and 86%. The complete remission (CR) rates were 66 and 71% with a median duration of 13 and 5.5 months respectively. Nodular types responded better than diffuse ones in both lymphocytic (CR rate 85% vs 45%; median duration 24+ months vs 2.5 months) and histiocytic lymphoma (CR rate 100% vs 0%). In lymphocytic lymphomas, survival in the responder group was 90% at 24 months vs only 20% in the nonresponder group (median survival 14.2 months). In the group with nodular lymphocytic lymphoma responding to therapy, there was a 100% survival rate at 24 months. The median survival for patients treated with chemotherapy alone (stage IV) and not responding to therapy, was 22 months vs 14.5 months in the whole nonresponder group (stages I, II, III, IV), suggesting a detremental effect of rediotherapy in the nonresponder group. In histiocytic lymphomas, the median survivals in the responder and nonresponder groups were 19 months and 3 months respectively. These results corroborate the excellent efficacy of the CVP regimen. They also indicate that, after CVP induction, 2 major prognostic factors are the histologic type and the nature of the response to therapy.
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A study of a series of adenolymphomas showed the presence of pigmented cells in the lymphoid stroma in 85% of the cases. The pigmented cells contained light brown cytoplasmic pigment and manifested sudanophila, acid-fastness, silver reduction capacity, PAS positivity and yellow autofluorescence in ultraviolet light. The morphology, histochemical reactions and autofluorescence suggest that the pigmented cells are macrophages containing ceroid derived from breakdown of damaged organelles of the epithelial tumor cells. It is possible that these cells play a role in the elimination of undigestable pigment material present in the cystic spaces of the tumor.
Six hundred and seventy-six patients had both their cataracts removed in one operating session because of the rural and economic conditions of Malawi. These operations were performed over a period of 5 years. The final visual results were satisfactory and the number of complications acceptable in relation to the environmental conditions and medical facilities available. However, the incidence of infection is higher than would be acceptable in a sophisticated medical environment. Three eyes were lost owing to infection, but fortunately in all 3 cases the fellow eye was not affected. Furthermore, broken capsule and vitreous loss occurred more frequently than expected in a sophisticated facility in the eye first operated on. This allowed measures to be taken by the surgeon in many cases to prevent these complications from recurring in the second eye.
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A comparative study of the effectiveness of Watson's and Cairns's trabeculectomy in a Black South African population with open-angle glaucoma is presented. The eventual success rate of 91-6% is comparable with that found in Whites, and the results were similar with both methods.
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60 patients with non Hodgkin's lymphomas were treated with a CVP induction regimen, either alone (stage IV) or in combination with radiotherapy (stages I, II, III). The response rates for lymphocytic and histiocytic lymphomas were 80 and 86%. The complete remission rates were 68 and 71% with a median duration respectively of 13 and 5.5 months. Nodular types did respond better than diffuse both in lymphocytic (CR rate 85% vs 44%; median duration 24 months +, vs 2.5) and histiocytic lymphoma (CR rate 100% vs 0%). In lymphocytic lymphomas, survival in the responding group was 90% at 24 months, vs 20% only in the non responding group (median survival 14.5 months). In the group with nodular lymphocytic lymphoma responding to therapy, there was a 100% survival rate at 24 months. The median survival for patients treated with chemotherapy alone (stage IV) and not responding to therapy, was 22 months, vs 14.5 months in the whole non responder group (stages I, II, III, IV) suggesting a detrimental effect of radiotherapy in the non responding group. In histiocytic lymphomas, the median survivals were respectively 19 months and 3 months in the responding and non responding groups. These results corroborate the excellent efficacy of the CVP regimen. They also indicate that, faced to a CVP induction, 2 major prognosis factors are the histologic type and the nature of the response to therapy.
Intracellular deposits of amyloid as defined by positive Congo red staining with green polarization birefringence and standardized toluidine blue staining with pink-red polarization birefringence were observed in the epithelial lining of three cases of calcifying odontogenic cysts. It is suggested that this material is not true amyloid but, rather, a dengenerative product of the epithelial cells as has been described in calcifying epithelial odontogenic tumor (Pindborg tumor).
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