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.

Basic fibroblast growth factor supports human olfactory neurogenesis by autocrine/paracrine mechanisms.

Throughout life, olfactory sensory neurons are renewed from a population of dividing stem cells. Little is known about the molecular mechanisms that regulate the activation, self-renewal and differentiation of olfactory neuronal precursors; however, evidence indicates that soluble mediators may play a central role in olfactory neurogenesis. To identify molecules that regulate olfactory self-renewal and differentiation, we have recently established, cloned and propagated in vitro primary long-term cell cultures from the human fetal olfactory neuroepithelium.

HIV-1 infection of primary human neuroblasts.

Central nervous system (CNS) disorders are frequent in HIV-1-infected individuals, particularly in newborns and children, and are accompanied by histological alterations resulting in neuronal loss. Although several tumor-derived neuroectodermal cell lines can be infected by HIV-1, it has been reported that primary neural cells cannot be infected after they differentiate. However, pediatric AIDS is often the result of HIV-1 infection occurring during fetal development and early postnatal life, when neural cells are not yet differentiated.

Insulin-like growth factor-I (IGF-I) and its binding protein IGFBP-4 in human prostatic hyperplastic tissue: gene expression and its cellular localization.

It has been previously reported that 1) type I insulin-like growth factor (IGF) receptors are present in the human prostatic tissue; 2) IGF-I receptors are mainly localized in the epithelial cells; 3) IGF-I is a mitogen for prostatic epithelial cells in culture; and 4) IGF-binding proteins (IGFBPs) are released by these cells in the conditioned medium. To add information on the mechanism of IGF-I action in the human prostate, we studied the expression and cellular localization of mRNA encoding IGF-I and IGFBP-4 in human prostatic hyperplastic (BPH) tissue. Northern analysis of total RNA extracted from BPH tissues with cDNA probes containing the entire coding regions for IGF-I and IGFBP-4 documented the presence of multiple IGF-I mRNA transcripts with lengths of 7.

Limb girdle muscular dystrophy with autosomal dominant inheritance.

We describe a patient suffering from limb-girdle muscular dystrophy with autosomal dominant inheritance proved by the presence of other similar cases in both sexes scattered over 4 generations of his family tree. In all patients the symptoms appeared in adult age and pelvi-femoral preceded scapulo-humeral involvement. Clinical expressivity has been variable, but rather benign without any reduction in life expectancy.

Sertoli cell proteins in the human seminiferous tubule.

It is well known that rat Sertoli cells in culture secrete both testis-specific proteins, such as inhibin and androgen binding protein (ABP), and proteins which are very similar, if not identical, to serum proteins, such as transferrin (TF), ceruloplasmin, and IGF-I. It is also well known that very few data have been reported about the secretory activity and the hormonal regulation of the Sertoli cell in man, mainly because of the difficulties associated with the isolation of pure cell populations from human tissue. Using histoimmunochemical techniques we tried to localize, with specific antisera, Sertoli cell proteins and, when possible, their receptors in the human testis.

Insulin-like growth factor-I (IGF-I) and IGF-I receptor in human testis: an immunohistochemical study.

Using specific monoclonal antibodies, the authors studied the distribution of insulin growth factor-I (IGF-I) and its receptor in normal human testis by immunostaining techniques. IGF-I was preferentially localized in Sertoli cells. Less evident positivity was found in primary spermatocytes.

Immunostaining of transferrin and transferrin receptor in human seminiferous tubules.

Transferrin (TF) and transferrin receptor (TFr) were studied in human testicular biopsy specimens with the use of immunostaining techniques. A polyclonal antibody to human TF (obtained in goat), a murine monoclonal antibody (B3/25) to human TFr, and antisera antigoat IgG and antimouse IgG, both labeled with peroxidase, were used. In seminiferous tubules of subjects with normal spermatogenesis, TF was found mainly in Sertoli cells and, in lesser amounts (probably related to the presence of receptor-TF complexes), in spermatocytes and early spermatids.