Discriminative capacity of fasting C-peptide levels in a functional test according to different criteria of response to a stimulus. A study of Brazilian insulin-dependent diabetic patients.

In order to study the discriminative capacity of the C-peptide basal values (BV) in a functional test, we analysed the C-peptide response curve after a mixed meal in 26 insulin-dependent patients. The five criteria of response used were: (1) any increment after the stimulus; (2) percentual increment above 21%; (3) absolute increment above 0.35 ng/ml; (4) incremental area above 42.76 ng.min.ml-1, and (5) peak value above 2.16 ng/ml. Considering the first two criteria, many patients showed positive responses, in the diabetic group as a whole and when we analysed patients with BV > or = 0.74 ng/ml and < 0.74 ng/ml separately. When we applied only the last three criteria the number of positive responses was considerably smaller. Moreover, the majority of patients with BV < 0.74 ng/ml could not increase their levels over the ones established above. In patients with BV > or = 0.74 ng/ml, the number of positive and negative responses were similar. The comparison between the subgroups achieves statistical significance only for incremental area (chi 2 = 3.55, p = 0.03). We conclude that the functional test was important mainly for patients with BV > or = 0.74 ng/ml, and could have been omitted for patients with BV < 0.74 ng/ml. The best criteria of response were those based on the mean minus two standard deviations of each parameter in a non-diabetic group (the last three criteria), especially the incremental area.

[Study of true precocious puberty in girls using clinical, laboratorial and imaging techniques]. / Estudo clínico, laboratorial e por métodos de imagem da puberdade precoce verdadeira em meninas.

This paper reviews the clinical findings, pituitary gonadotrophin reserve, plasma estradiol and androgens, radiological findings and pelvic ultrasound appearance in 17 girls with true precocious puberty (PP), and attempts to asses the value of these tests diagnosis in the clinical management of such patients and better understanding of the pathogenesis of this disorder. As noted in other series, acceleration of growth is one of the earliest features of PP and at the time of diagnosis bone age can be already significantly advanced. In 3 (18%) patients intracranial abnormalities were present. Ultrasound examination showed changes similar to those seen during normal puberty. To conclude, the introduction of high-resolution methods (CT scan and RM) and techniques for ultrasound examination have greatly simplified the clinical investigation of female precocious puberty.