No abstract

that the lesion may be the result of a hitherto unknown type of hypersensitivity response.Our results do not show that the adverse effects of practolol are due to a hypersensitivity reaction, but two pieces of evidence might tentatively support such a conclusion. The first is the low antibody concentrations found in the sera of patients with sclerosing peritonitis. This might have been due to a reduction in antigenic stimuli, since the patients had been taken off the drug some time before the clinical signs of intestinal obstruction appeared. Equally, however, the results could be explained by postulating that the antigenic metabolite is incorporated into connective tissue and the mass of antigenic determinants presented by the peritoneum is sufficient to fix most of the circulating antibody. The second piece of evidence is perhaps more pertinent and concerns the challenge study on one of the patients (case 4). This patient had high concentrations of circulating antibody before challenge with practolol, and when the drug was given, clinical signs of the tissue damage were produced. Other patients in the study might have shown an adverse response if the drug had been given for a longer period.Continued analysis of serum will probably provide only circumstantial evidence of a practolol-induced hypersensitivity reaction. An animal model is needed to study the tissue damage produced by the drug, and we are currently engaged in studies of this kind.

The hands of 299 diabetic patients with and 161 without retinopathy were examined for abnormalities. Almost all abnormalities were finger joint contractures resulting in limited joint mobility (LJM) and/or Dupuytren's contractures (DC). Both LJM and DC occurred not only in insulin-dependent diabetes (IDDM) but also in non-insulin-dependent diabetes (NIDDM). In retinopathy patients LJM and DC occurred in 48% and 36% of patients, respectively, compared with 24% and 16% in those without retinopathy. These differences were statistically significant (P less than 0.001). The higher prevalence of LJM in the retinopathy group affected mainly those with severe retinopathy, there being no difference between background and nonretinopathy patients. DC was less clearly related to severe retinopathy. LJM was more severe in those with than without retinopathy. LJM and DC were also related to age and duration of known diabetes. Subgroups matched for age and duration of known diabetes showed that the main relationship of hand abnormalities was to retinopathy in IDDM, but more to age and duration of known diabetes in NIDDM.

No abstract

This study describes a method for quantifying microaneurysms (MA) from fluorescein angiograms. The method was validated by the reproducibility of the number of MA in 30 angiograms read twice each by two independent observers; and by the absolute difference in MA counts between two readings by the same observer, and difference in numbers counted by two different observers. The precise location of each MA on two readings was also studied and the reproducibility of location varied from 60 to 71%, depending on the quality of the angiograms. Clinicians and technicians working in the same or in different centers obtained similar results. The coefficient of correlation between observers and between readings was satisfactory, r greater than 0.9. The method is easy to learn and the reproducibility allows for its use in clinical trials.