General medicine and surgery for dental practitioners. Part 7: renal disorders.

Patients with kidney disorders are increasingly encountered in dental practice due to improvements in medical care leading to prolonged life expectancy. In order to provide appropriate and safe dental care for these patients it is important to have a working knowledge of renal disorders and related problems.

Epidemiologic features of hepatitis B virus infection in northern Labrador.

We studied the epidemiologic features of hepatitis B virus (HBV) infection in northern Labrador to determine the prevalence of the infection and to obtain a database to develop a vaccination strategy. The study population included seven communities in which five ethnic groups were represented: Inuit, Innu, mixed Inuit and European ancestry ("settler"), nonnative/nonsettler transient population ("white") and people of Innu-white or Innu-Inuit origin ("mixed"). Blood samples from 2156 people (62% of the area residents) were tested for antibody to HBV core antigen (anti-HBc), HBV surface antigen (HBsAg), HBV e antigen (HBeAg), anti-HBc IgM and antibody to the surface antigen (anti-HBs). The overall crude prevalence rate of HBV seromarkers was 14.7% and the HBsAg carrier rate at least 3.2%; the rates were highest for Inuit (26.4% and 6.9% respectively), followed by settler (10.0% and 1.9% respectively) and Innu (7.6% and 0.4% respectively); the white and mixed groups had the lowest overall rates (2.5% and 3.3% respectively). Although the overall prevalence rates were about the same for the two sexes, the HBsAg carrier rate was higher in males (male:female ratio 1.6:1.0). No HBV carriers were positive for HBeAg or anti-HBc IgM antibody. The rate of exposure to HBV was 4% for those below the age of 20 years and reached a peak for those aged 45 to 54 years (85% for Inuit, 40% for settlers and 37% for Innu). There was also a wide variation in the age-standardized prevalence rates (0% to 27.9%) among the ethnic groups in the seven communities surveyed.

A simple technique for recording and counting sweat pores on the dermal ridges.

A simple method was devised for recording dermatoglyphics in a form suitable for sweat pore counting. Fifteen members of a family with a hypohidrotic X-linked ectodermal dysplasia made their own hand prints using our method and mailed the results to us for interpretation. The simplicity of the technique also makes it practical to use on new-born males at risk for the condition, or where dermatoglyphic records are required for other purposes. Preliminary data suggest that patchiness of sweat pore distribution on the fingers and palms may be useful in the discrimination of heterozygotes.

Antihypertensive efficacy of alpha-methyldopa, chlorothiazide and Supres-150 (alpha-methyldopa-chlorothiazide).

Twenty-two white men and two white women with uncomplicated essential hypertension participated in a randomized double-blind trial comparing placebo with alpha-methyldopa (750 mg/d orally) and chlorothiazide (450 mg/d orally), alone or in combination. There were no significant differences in blood pressures as measured with the patients lying down; however, with the patients standing the systolic, diastolic and mean arterial blood pressures were significantly lower (P < 0.05) after treatment with alpha-methyldopa or the combination product. The higher the blood pressure before treatment, the greater the fall with treatment. Adverse effects were infrequent.

A search for association between IgD concentrations and immunoglobulin allotypes in 936 sera from a genetic isolate in Newfoundland.

Immunoglobulin allotype (Gm) data has been analysed agaonst immunoglobulin D (IgD) concentrations in a population study in Newfoundland. There was no significant difference between the distribution of IgD concentrations in people homozygous for the alleles G1m(f) and G3m(b) when compared with people homozygous for the alleles G1m(a) and G3m(g). These findings, involving 573 homozygous individuals as opposed to ninety-eight in an earlier study on a New York population, do not confirm the earlier findings. Thus a genetic influence on IgD concentration by Gm genes or genes closely linked to them is not universally demonstrable by typing for these four markers and by using the Mancini technique for mearusing IgD concentration.

Serum lipids in hypothyroidism--a re-evaluation.

One hundred and forty-two persons referred for assessment of thyroid function were studied in relation to their thyroid function and fasting serum lipids. Forty-five individuals, who had no family history of thyroid disease, were euthyroid, and were negative for thyroid antibodies formed the control group. The remaining 97 patients were fitted into six groups as follows--euthyroid Hashimoto's thyroiditis, thyroiditis with exagggerated TSH response to TRH, and four groups of increasing grades of thyroid failure based on the level of serum TSH. Only in the two most severely hypothyroid groups was cholesterol significantly elevated as compared with control levels. A graded increase in mean serum triglyceride, was observed as thyroid failure increased; however, values were not different (P greater than 0.05) from the control group. However, partial correlation analysis indicated that serum cholesterol was related to increasing levels of serum TSH and that this dependency was not influenced by age or weight. Although serum cholesterol was related to thyroid function in the study population, it was an insensitive indicator of the metabolic effects of thyroid hormone.