Insulin hypoglycemia test and releasing hormone (corticotropin-releasing hormone and growth hormone-releasing hormone) stimulation in patients with pituitary failure of different origin

To investigate the efficacy of endocrine evaluation in diagnosing and localizing the cause of anterior pituitary failure, 17 patients with suprasellar space-occupying lesions, 4 patients with intrasellar tumors, 8 patients with no detectable anatomical lesion, 1 patient with posttraumatic failure and 1 patient with septooptical dysplasia were investigated. Endocrine evaluation consisted of measuring adrenocorticotropic hormone (ACTH), cortisol, and growth hormone (GH) levels during insulin hypoglycemia test (IHT) and after administration of corticotropin-releasing hormone (CRH) and growth hormone-releasing hormone (GRH). In addition, basal prolactin levels, gonadal and thyroid function were evaluated. The results showed that 4 of 17 patients with suprasellar tumors had normal ACTH and GH responses during IHT and after releasing hormone (RH) administration. Five of these patients had a normal ACTH or cortisol rise but no GH response during IHT. All 5 had a normal ACTH and 3 had normal GH rise after RH. Seven patients with suprasellar tumors had no ACTH or GH response during IHT, but all had an ACTH response to CRH. Only 3 of this group had a GH response to GRH. There was one exception of a patient who showed a GH and ACTH rise during IHT but only a blunted ACTH and no GH rise after RH administration. Four patients with pituitary failure and no demonstrable lesion had an ACTH rise after CRH but no GH rise after GRH, whereas in 3 patients with isolated ACTH deficiency no ACTH rise after CRH was seen. In 4 patients with nonsecreting pituitary tumors normal ACTH responses to IHT and CRH were seen, whereas GH rose during IHT only in 1 patient.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spontaneous apoptosis, oxidative status and immunophenotype markers in blood lymphocytes of AIDS patients.

Peripheral blood mononuclear cells (PBMC) from 251 HIV-positive drug abusers of known clinical stage and from 40 healthy donors were tested for conventional immunologic markers (CD3, CD4, CD8, CD19, CD14, CD16/CD56, CD45 and HLA-DR). Additional cell parameters and the occurrence of spontaneous apoptosis (programmed cell death) were investigated on freshly isolated PBMC by flow cytometric measurement of either annexin-V bound to plasma membrane phosphatidylserine or propidium iodide uptake. The activity of gamma-glutamyltransferase (gamma-GT), an ectoenzyme contributing to the synthesis of the intracellular antioxidant glutathione (GSH) and involved in early apoptosis, was also determined in these cells. Immunocompetent T-cell counts were lower in HIV+ patients, with the exception of CD8+ and HLA-DR+ lymphocytes. The external binding of annexin-V was significantly higher in HIV+ PBMC and occurred in both CD8+ and CD4+ T-lymphocyte subsets. The activity of gamma-GT, was significantly lower in the PBMC from HIV+ patients, indicating that the redox status of PBMC may be affected in HIV+ individuals. Finally, the most dominant features characterising patients receiving antiretroviral therapy were greater long-term stability in the distribution of various cell parameters excepted the level of apoptosis.     

Ultrastructural complexity of nuclear components during early apoptotic phases in breast cancer cells.

Fractal morphometry was used to investigate the ultrastructural features of the plasma membrane, perinuclear membrane and nuclear chromatin in SK-BR-3 human breast cancer cells undergoing apoptosis. Cells were incubated with 1 microM calcimycin (A23187) for 24 h. Cells in the early stage of apoptosis had fractal dimension (FD) values indicating that their plasma membranes were less rough (lower FD) than those of control cells, while their perinuclear membranes were unaffected. Changes of the chromatin texture within the entire nucleus and in selected nuclear domains were more pronounced in treated cells. This confirms that the morphological reorganization imputable to a loss of structural complexity (reduced FD) occurs in the early stage of apoptosis, is accompanied by the inhibition of distinct enzymatic events and precedes the onset of conventional cellular markers, which can only be detected during the active phases of the apoptotic process.