Methylmethacrylate screw implants—radiographic, histological and fluorescence microscopic investigations in dogs

Twenty-one methylmethacrylale screw implants were inserted in the jaws of three Labrador dogs. Clinical, radiographic, microscopic and fluorescence microscopic examinations were performed. Direct bone-implant contact was found in all firm implants, and the density of the alveolar bone increased towards the screw surface. In these areas no fibrous tissue was found between bone and implant. Horizontal fibres at the junction between the head and the neck of the implant seem to have impeded downgrowth of subepithelial granulation tissue.     

Effects of Metoprolol on the Counter-regulation and Recognition of Prolonged Hypoglycemia in Insulin-dependent Diabetics

ABSTRACT. The effect of metoprolol on the counter-regulation of prolonged hypoglycemia was studied in eight insulin-dependent diabetics. Insulin was given as an i.v. infusion of 2.4 U/h over 180 min alone, or together with metoprolol (3.0 mg i.v. bolus followed by an i.v. infusion of 4.8 mg/h) in random order. Blood glucose, counter-regulatory hormones, hypoglycemic symptoms and the cardiovascular responses were assayed over 240 min. Metoprolol did not significantly modify the blood glucose levels. The plasma levels of free insulin, however, were elevated by approximately 20% (p<0.01) by metoprolol during hypoglycemia and the plasma concentrations of epinephrine, norepinephrine, growth hormone and cortisol were enhanced by the drug. Sweating was increased by metoprolol, while other symptoms were unaltered. We conclude that metoprolol administered acutely does not aggravate prolonged hypoglycemia in diabetics with blunted response of glucagon. Moreover, exaggerated responses of counter-regulatory hormones, provoked by metoprolol, may compensate for the inhibitory effect of this drug on insulin clearance.     

Capillary supply and muscle fibre types in patients with intermittent claudication: relationships between morphology and metabolism

Abstract. There have been previous reports on an increased oxidative capacity in muscle tissue from the diseased legs of patients with intermittent claudication. The present study was designed to correlate metabolic and morphological data and to investigate whether the metabolic adaptive changes in muscle tissue of claudicating legs were also reflected in morphological variables such as capillary supply, fibre type distribution, and fibre area. The activity of cytochro-me-c-oxidase in gastrocnemius muscle was determined and the insulin and glucose uptakes were measured across the leg in the basal state and 10 min following intravenous administration of 25 g glucose. The finding of a reduced relative number of Type II B fibres and a reduced ratio Type II B/II A fibre area, as well as an increased capillary supply to Type II A, indicated that the most extensive morphologic changes in muscle tissue of claudicating legs had occurred in Type II fibres. The increased number of capillaries in contact with Type IIA fibres in muscle tissue from claudicating legs, compared with muscle tissue from control legs, suggested that the most apparent metabolic changes occurred in this fibre type in the adaptation process of these patients. The more pronounced morphologic and metabolic changes in Type II fibres suggest that these fibres are more intensely activated than Type I fibres during physical activity in claudicating legs. The insulin uptake correlated positively with the number of capillaries per fibre, suggesting that the endothelial surface area is one of the determining factors for insulin uptake. The percentage of Type II B fibres reflected to a certain extent the metabolic adaptation in muscle tissue.     

In vitro lymphocyte reactivity to gold compounds in the diagnosis of contact hypersensitivity

The use of the lymphocyte transformation test (LTT) in the diagnosis of contact hypersensitivity to gold was studied in 8 patients who had positive patch tests to gold salts, and in 8 control subjects who were negative to such patch tests. Gold sodium thiosulfate and gold chloride were added to cultures of lymphocytes, which were labeled by 3H-thymidine after 96 h. The lymphocyte stimulation index was calculated as the beta-counts in stimulated cultures divided by those in control cultures. The index was statistically significantly higher for the patient group (p=0.005-0.04) than for the control group. Levels of interferon-gamma (IFN-gamma) were determined for the supernatants of the lymphocyte cultures. An index IFN-gamma, which is defined as the level of IFN-gamma in stimulated cultures divided by that in control cultures, was statistically significantly higher for the patient group (p=0.01-0.006). The LTT stimulation index showed specificity and sensitivity between 67 and 80%, the respective values for Index IFN-gamma being between 73 and 100% when the patch test was used as a reference method. Evaluation of lymphocyte reactivity might be of future interest in the diagnosis of allergic reactions to gold if the sensitivity and specificity can be improved.     

Histochemical studies on cholesterol formation in odontogenic cysts and granulomas

abstract — A histologic and histochemical study was made of 45 odontogenic periapical cysts and granulomas with cholesterol formation. The specimens were transported in Histocon® solution and sectioned by cold microtome. This technique permits the preservation of the lipids and rertains the enzyme activities in the cells. Cholesterol crystals seemed to be formed in disintegrating clots of red blood corpuscles in congested capillaries of the inflammatory areas. The pericytes of the vessel walls changed their enzyme activities, indicating increased lysosomal functions, and eventually formed giant cells with tissue degrading properties.     

Dental root translucency as an indicator of age

Abstract – The apical translucent zone was studied in 1000 human teeth. For each type of tooth, excluding molars, the size of the apical translucency was estimated according to the scoring methods of G ustafson (I), D alitz (2) & J ohanson (3). The lengths of the translucent zones were measured on moist and then on dry teeth, both unsectioned and sectioned, while the areas were measured on dry sectioned teeth only. Statistical analyses using the SPSS package in a Cyber computer indicated a symmetric distribution of the translucent zone in left and right teeth. The extent of the translucency showed little variation from one type of tooth to another. The length of the translucent zone measured on unsectioned teeth demonstrated in most types the closest relation to age. Multiple regression analyses, including more than one method of measuring the size of the translucent zone, resulted in formulas showing a high correlation with age (from 0.68 to 0.86). Slightly larger translucent areas were found in teeth from males, in darker teeth and in teeth with increased thickness of the cementum. The increase in the translucent zone with advancing age was found to be almost linear and was not affected by periodontal destruction.