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Biomedical subjects

R David

Publications and source records attributed to R David.

At least 235 records · Page 13Linked to original sources
PubMed1978

Corpora amylacea in mesothelioma of the atrioventricular node.

Rounded or polyhedral, acellular, dense lamellated structures were seen within gland-like spaces in a case of atrioventricular mesothelioma. These structures exhibited many of the histochemical characteristics of amyloid, viz., pink colour with green birefringence and bright red fluorescence with alkaline Congo red; ortochromasia and red birefringence with standardised toluidine blue; positive DMAB-nitrite and diazotisation coupling reactions and spontaneous autofluorescence. It is suggested that these bodies are derived from spontaneous assembly or polymerisation of microfibrils of desquamated cells lining the cystic spaces of the tumour as occurs in prostatic corpora amylacea. The peculiar intramyofibre proliferation of tumour cells in the peripheral part of the tumour suggests that viable tumour cells can penetrate, survive and proliferate within atrial or nodal myofibres leaving an intact sarcolemmal sheath. The slow tumour cell growth and the successive degeneration of central tumour cells may explain the tubular and/or glandular pattern constantly seen in this tumour.

Aged↗
PubMed1978

Lipofuscin in salivary glands in health and disease.

Lipofuscin granules were observed in normal salivary glands (parotid, submandibular, and minor salivary glands). The pigment was confined mainly to the epithelial cells of the intralobular ducts, but isolated granules were also found in acinar cells and myoepithelial cells. In chronic sialadenitis pigment granules were found in the intralobular epithelial cells and in macrophages in the surrounding ionnective tissue. In benign epithelial tumors pigment granules were observed within neoplastic epithelial cells and in macrophages in the stroma, while malignant tumors displayed pigmented granules only in macrophages in the stroma.

Adenoma, Pleomorphic↗
PubMed1978

Corpora amylacea in adenolymphoma (Warthin's tumor).

Round or polyhedral, acellular, lamellated or amorphous eosinophilic structures were observed in the cystic spaces of adenolymphomas. These eosinophilic bodies ahd several of the histochemical characteristics of amyloid, viz., pink color with green specific birefringence and bright red fluorescence with alkaline Congo red; positive DMAB-nitrite and DC reactions, and spontaneous autofluorescence. It is suggested that these bodies are derived from spontaneous assembly or polymerization of microfibrils of desquamated epithelial cells lining the cystic spaces of the tumor, as has been described to occur in prostatic corpora amylacea.

Adenolymphoma↗
PubMed1978

Lipopigment in odontogenic cysts.

A study of 105 odontogenic cysts revealed the presence of pigmented cells in the cyst wall in 38% of the cases. The frequency of pigmented cells was higher in the inflammatory odontogenic cysts than in the development cysts. Although isolated pigmented cells were seen within the epithelial lining and cyst cavity, the larger collections were closely associated with cholesterol crystals and hemosiderin deposits; they contained light brown cytoplasmic pigment which manifested sudanophilia, 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 ceroids. It has been suggested that the hemosiderin which is found in the cyst wall serves as an oxidation catalyst for the locally liberated lipids, the end result of which is the formation of the ceroid pigment.

Cholesterol↗
PubMed1978

Ocular hypertension: a comparative follow-up of black and white patients.

Forty-four eyes in 25 black patients are compared with 92 eyes of 47 white patients in a population with ocular hypertension followed up for 1 to 12 years in a glaucoma clinic. The black patients present at a younger age than the whites and their mean initial intraocular pressure is significantly higher. The fact that more black ocular hypertensives developed glaucoma--8 eyes (18.1%) in the black population as compared with 5 eyes (5.4%) in the white population--is attributed to these two differences.

Adult↗
PubMed1978

Follow-up of aphakic patients with anterior vitrectomy in one eye and uneventful cataract extraction in the fellow eye.

Twenty patients had operations for bilateral cataract in 2 separate sessions, with uncomplicated extraction on one side and vitreous loss managed with anterior vitrectomy on the other. The cataracts, the type of surgery, and the postoperative treatment were identical in both eyes. The differences between the 2 eyes were not statistically significant so far as the amount of astigmatism, final visual acuity, and peripheral anterior synechiae were concerned. The main difference was found to be the period of time the vitrectomised eyes remained red and uncomfortable as compared to the eyes with uncomplicated surgery.

Aged↗
PubMed1978

Aniridia associated with microcornea and subluxated lenses.

Four cases of aniridia associated with subluxated lenses and microcornea are presented. The triad occurred in both eyes of the 4 affected members in one Ndebele family (one of the South African Negro tribes). No other ocular or systemic defects were noted, and intelligence was normal. Chromosomal studies on both parents showed no abnormality, and gene marker studies failed to reveal any linkage between the disease locus and a wide range of polymorphic loci.

Adolescent↗
PubMed1978

Influence of pH on the efficacy of pilocarpine.

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.

Clinical Trials as Topic↗
PubMed1978

Burkitt's lymphoma in Israel.

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.

Africa↗
PubMed1977

[Lumbosacral arachnoepiduritis. Clinical and etiologic aspects].

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.

Arachnoiditis↗
PubMed1977

The metabolic effects of excess noradrenaline secretion from a pheochromocytoma.

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.

Adolescent↗
PubMed1977

Combination of cyclophosphamide, vincristine, and prednisone, followed by maintenance chemotherapy, with and without radiotherapy, in the management of patients with non-Hodgkin's lymphomas.

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.

Adolescent↗
PubMed1977

Pigmented cells in adenolymphoma (Warthin's tumor).

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.

Adenolymphoma↗