Different modulation of dipeptidyl peptidase-4 activity between microvascular and macrovascular human endothelial cells.

Dipeptidyl peptidase 4 (DPP-4) is an enzyme that is produced by endothelial cells in different districts and circulates in plasma. Patients with type 2 diabetes show a reduction in active Glucagon-Like Peptide-1 (GLP-1) that could be due to impairment of secretion or its degradation or both. GLP-1 is rapidly inactivated in vivo, mainly by the DPP-4.

Dipeptidyl peptidase-IV expression and activity in human glomerular endothelial cells.

Glucagon-like peptide-1 (GLP-1), a meal-stimulated gastrointestinal insulinotropic hormone inactivated by dipeptidyl peptidase-IV (DPP-IV), is reduced in type 2 diabetic patients. The present study shows that 2-week exposure of human glomerular endothelial cells to high glucose (22 mM) determines a highly significant increase in DPP-IV activity and mRNA expression, which cannot be entirely accounted for by hyperosmolarity. On the other hand, incubation of purified DPP-IV in a buffer solution added with high glucose does not affect enzyme activity.

Immunohistochemical localization of mast cells as a tool for the discrimination of vital and postmortem lesions.

In wounds that are inflicted at least 60 min before death, histamine levels can increase up to 100%. This functional effect might have a morphometric counterpart. Mast cells play a crucial role in acute inflammatory reactions and in the healing process of wounds.

Oligodendroglioma: HMB-45 positivity using catalyzed signal amplification method: an immunohistochemical (HMB-45, CD31, p53, Mib-1) and ultrastructural study.

Although melanin synthesis and the presence of melanosomes are exceptionally reported in nervous system tumors, there is no record of melanotic oligodendrogliomas in the literature. The purpose of the current study was to evaluate whether melanosomes are immunohistochemically and ultrastructurally detectable in nonmelanotic oligodendrogliomas and to verify whether these data are related to prognosis. Thirty surgical specimens (19 primary lesions and 11 recurrences) from 19 patients were examined.

Inflammatory cytokines and HIV-1-associated neurodegeneration: oncostatin-M produced by mononuclear cells from HIV-1-infected individuals induces apoptosis of primary neurons.

Neurologic abnormalities are common in HIV-1-infected patients and often represent the dominant clinical manifestation of pediatric AIDS. The neurological dysfunction has been directly related to CNS invasion by HIV-1 that is principally, if not exclusively, supported by blood-derived monocytes/macrophages and lymphocytes. By using primary long term cultures of human fetal sensory neurons as well as sympathetic precursors-like neuronal cells, we determined that blood-derived mononuclear cells from HIV-1-infected individuals spontaneously release soluble mediators that can potently inhibit the growth and survival of developing neurons as well as the viability of postmitotic neuronal cells by inducing apoptotic cell death.