An Improved Method of Removing Polyurethane Foam-Covered Gel Prostheses

One of the advantages of polyurethane foam-covered prostheses has been that in the first 5 to 10 years after their use, the amount of capsular contraction was found much less than when similar ``slick' prostheses were used. Another advance was their fixation to the surrounding tissue thus giving a more natural appearance and movement with the muscles when the arms were moved in any direction. The formation of a thick capsule also acted as a protection against gel granuloma due to rupture of the prosthesis and has been thought to be a factor in the lower capsule contraction rate. The greatest disadvantage has been that its removal was extremely difficult and this has continued up until the technique described in this paper has been introduced.     

Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.     

Addition of sulfonylurea to insulin treatment in poorly controlled type II diabetes. A double-blind, randomized clinical trial

This study examined the potential beneficial effects of the addition of a second-generation sulfonylurea to insulin therapy for poorly controlled type II diabetes. A randomized, double-blind, crossover experimental design was utilized in 16 type II diabetic patients for a period of eight months. Treatment with glyburide, 20 mg/d (plus insulin), compared with placebo (plus insulin) resulted in a significant reduction in mean basal glucose (232 +/- 12 vs 262 +/- 11 mg/dL [12.8 vs 14.4 mmol/L]) and hemoglobin A1C (10.2% +/- 0.5% vs 10.9% +/- 03%) concentrations. Concomitant with this change, basal C-peptide and free insulin values increased with glyburide therapy, but this pharmacological agent did not alter the ability of the patient's erythrocytes to bind insulin. We conclude that in type II diabetic subjects receiving more than 28 units of insulin per day, the addition of glyburide results in a marginal, but statistically significant improvement in basal glucose concentration, but not in glucose tolerance as assessed by integrated glucose concentration. Whether this small improvement in glycemia is worth the additional cost of sulfonylureas or the risk of drug side effects is not known.     

Reconstruction of mandibular defects with metallic prostheses and microvascular jejunal autografts: an experimental study

A study was undertaken to determine the adequacy of vascularised jejunum to provide stable mucosal cover over a non-biological mandibular substitute. Employing a canine model, composite intra-oral bone-mucosal defects were created and reconstructed with a metal plate covered by a microvascular jejunal patch. These were followed for six months and were assessed clinically, histologically and radiologically. Rapid mucosal healing occurred in all cases. The autografts conformed to the contour of the prosthesis and adequate tongue mobility was preserved. All mandibles remained stable throughout the follow-up period. Histologically, short villi covered the jejunal grafts to three months whilst at six months both normal and abnormal jejunal mucosal morphology was evident.     

The significance of resection length on the patency rate, and the histopathology, of experimentally avulsed and microsurgically repaired blood vessels

The significance of resection length on patency rate, and the histopathology, of microsurgically repaired avulsed blood vessels was examined at 3 weeks in two groups of experimentally avulsed rabbit femoral arteries repaired by different surgeons and in a single series of avulsed and repaired veins. All veins were patent 3 weeks after avulsion and microsurgical repair. Histopathology indicated that the vast majority of lesions in veins were removed at resection. Surgeon A achieved 75% patent arteries and Surgeon B achieved 100% arterial patency (resecting 3.7 mm more on average than Surgeon A). Histopathology revealed numerous luminal circumferential lesions remained in the avulsed artery wall following resection. These lesions were sites of smooth muscle cell proliferation and neointima formation. Although similar arterial damage occurs in human avulsion, considerably lower patency rates are achieved for human arterial avulsion repair than were reported in this experimental study. Factors in addition to vessel wall damage must therefore be involved in thrombosis and occlusion of repaired avulsed arteries. Such factors might be lengthy ischaemia time and severe spasm.