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Biomedical subjects

D Benezra

Publications and source records attributed to D Benezra.

At least 37 records · Page 2Linked to original sources
PubMed1984

Cellular and humoral immune parameters among patients with retinitis pigmentosa and other retinal disorders.

Patients with retinitis pigmentosa, other retinal degenerations and a group of normal volunteers were included in a masked study designed to examine the existence of autoimmune reactions toward retinal antigens and the possible defect in lymphokine production (IL-1, IL-2 and gamma interferon). The results obtained did not show any specific anamnestic response to the retinal S-Ag nor any outstanding defect in gamma interferon production by the lymphocytes of patients with retinitis pigmentosa. It is suggested that a larger masked study be conducted as soon as possible in order to clarify these aspects of immune aberrations in patients with retinitis pigmentosa.

Antibody Formation↗
PubMed1979

Stimulation of keratocyte metabolism by products of lymphoid cells.

Products of leukocytes were found to activate cultures of keratocytes, manifested by the increased incorporation of thymidine or leucine. The keratocyte activation capacity crosses the species barriers between rabbit, monkey, and human. The level of secreted keratocyte-activating factor(s) (KAF) depends on the stimulation of the leukocytes. Thus unstimulated rabbit leukocytes produced very little or no KAF, whereas significant levels were produced by leukocytes stimulated with lipopolysaccharide (LPS) or concanavalin A. High levels of KAF were also found in supernatants of human mononuclear leukocytes stimulated by LPS. The effects of the activated leukocyte supernatants on keratocyte metabolism resembled the increased metabolic activity induced by the fibroblast and epidermal growth factors. The relationship between KAF and a possible modulating role of the products of lymphoid cells on corneal wound healing is suggested.

Animals↗
PubMed1978

Bilateral versus unilateral cataract extraction: advantages and complications.

Cataract extraction was performed on 734 patients. These were followed up postoperatively for up to 1 year. In 448 cases the extraction was performed in both eyes during 1 operating session (896 eyes) and in 1 eye in 286 cases, a total of 1182 cataract extractions. Preoperatively more than 75% of the eyes in both groups had perception of light only. Postoperatively more than 85% of eyes in both groups achieved a visual acuity of 6/30 or better. The postoperative visual performance of an eye was not influenced by the mode of operation, bilateral or unilateral. The overall incidence of complications among the 1182 operated eyes was: accidental extra-capsular cataract extraction 10.2%, vitreous loss 11.0%, hyphaema 1.4%, flat anterior chamber 0.9%, dehiscence of the wound 0.5%, uveitis 1.2%, endophthalmitis 0.3%, secondary glaucoma 0.9%, severe bullous keratopathy 1.4%, oedema of the macula 0.5%, and retinal detachment 0.3%. The complications in both groups of patients were comparable. Only in 1 case operated in both eyes vision was not restored following a bilateral endophthalmitis.

Cataract Extraction↗
PubMed1977

Incidence and causes of blindness among the under 5 age group in Malawi.

The expected incidence of blindness among children under 5 years of age in Malawi is 34 cases per 100 000 children. Direct ocular infections were responsible for the blindness in 32% of the cases (bacterial infections 20% and measles 12%). The instillation of traditional medicine in these cases worsened the ocular condition and induced in all of the cases a "hopeless" situation of total melting of the cornea and protrusion of the uvea. Congenital factors (excluding retinoblastomas) were responsible for 30-8% of the blind cases. Among these, 11 cases of congenital cataracts were successfully treated and will not appear as blind in future. A high incidence (9-3%) of cortical blindness was recorded. Trauma was implicated in 5-3%, while retinoblastoma was found in 8%. It is believed that adequate preventive measures should be able to lower the incidence of blindness among this age group to 5 cases instead of 34 per 100 000 children.

Bacterial Infections↗
PubMed1976

Experimental specific memory reaction to cornea, lens, and retina antigens.

Lymphocytes from rabbits immunized against various ocular extracts were challenged in vitro by the immunizing extract, by other ocular extracts from the same species, and by analogous extracts from other species. Immunological memory reaction, demonstrated by the blast transformation phenomenon, was found toward organ-specific and species-specific antigens. The organ cross-reactivity was greatest when cornea and lens were tested. Immunization of rabbits against calf cornea with extract emulsified in Freund adjuvant injected into the hind foot-pads induced the appearance of specific memory cells in popliteal lymph nodes, spleen, and blood. Immunization by interlamellar xenografting has shown that memory lymphocytes are mainly localized in the preauricular lymph nodes and are nearly absent from spleen and popliteal lymph nodes. These findings indicate the important role of the local immunological mechanism of the eye.

Animals↗
PubMed1976

Causes of blindness among students in blind school institutions in a developing country.

Out of 270 students in 17 blind school institutions in Malawi 73 per cent were blind before the age of three. The most common cause for the blindness was ocular infection (75-2 per cent). Meales, as a single cause, was responsible for 43-7 per cent of the cases and smallpox for 5-2 per cent. Bacterial infections were incriminated in 26-3 per cent of the cases. Most of these had received traditional medicine during the acute phase of the disease. Hereditary factors as causes of blindness were found in 7-8 per cent of the cases. These included congenital cataracts (2-6 per cent), optic atorphy of unknown origin (3-0 per cent), microphthalmos (1-5 per cent), and macular degeneration (0-7 per cent). Careful ophthalmological examination showed that in 37 cases an intervention could be attempted in order to improve the vision. In the 11 most favourable cases this was attempted, with the result that nine cases gained a useful vision of 4/60 to 6/18 in the better eye.

Adolescent↗
PubMed1976

Transposition of vertical recti for residual tropias.

Transposition of vertical muscles for residual tropia was performed: nasal displacement for exotropia and temporal displacement for esotropia. Five millimeter equal displacement of superior and inferior recti corrected 10 to 14 prism diopter while equal displacement of 7 to 8 mm resulted in correction of 25 prism diopter. Special indications of this procedure may be: (1) residual tropia in cases with severe intractable ambylopia or pathology in one eye where patient and surgeon may be reluctant to operate on the sound eye, or (2) residual tropias of the alternating type in patients who underwent operations in all horizontal muscles of both eyes.

Amblyopia↗
PubMed1975

Growth and transplantation of organ-cultured corneas.

Calf corneal buttons were grown in medium M199 supplemented with newborn calf serum (xenogeneic to the recipient) or rabbit serum (allongeneic to the recipient) and implanted interlamellarly into rabbit recipients. Implantation of buttons, grown in medium containing calf serum were rejected sooner than noncultured buttons. The rejection was quicker as the grafts were kept longer in culture. However, corneal buttons grown in medium containing rabbit serum showed, in general, a slower rejection process.

Animals↗