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R Garcia del Moral

Publications and source records attributed to R Garcia del Moral.

13 recordsLinked to original sources
PubMed1997

Cytokines and Fas regulate apoptosis in murine renal interstitial fibroblasts.

Renal fibrosis is characterized by an increased number of fibroblasts and excessive deposition of extracellular matrix. Apoptotic cell death is a physiological mechanism to limit cell numbers, and an insufficient rate of death may contribute to fibroblast accumulation. However, little is known about the regulation of renal fibroblast survival. The authors have studied the interaction of cytokines and the Fas receptor in the regulation of apoptosis of renal fibroblasts and have observed that murine renal fibroblasts express Fas and the Fas ligand. Tumor necrosis factor alpha (TNFalpha) and agonistic anti-Fas antibodies induce apoptosis of renal fibroblasts in a time- and dose-dependent manner. Serum contains survival factors for renal fibroblasts. Both serum deprivation and TNFalpha increase the sensitivity to Fas-induced death and the expression of fas mRNA and Fas receptor. By contrast, insulin-like growth factor-1 decreases apoptosis induced by both serum deprivation and Fas activation and partially prevents the increase in Fas receptor expression induced by serum deprivation. Murine renal fibroblasts express constitutively both fas ligand mRNA and cell-surface Fas ligand, but the authors could not demonstrate a role for Fas ligand in the autocrine regulation of fibroblast survival. These data suggest that Fas and other cytokines cooperate to regulate renal fibroblast apoptosis. Modulation of the Fas death-signaling pathway in renal fibroblasts could represent a new therapeutic target for renal fibrosis.

Animals↗
PubMed1993

Mononuclear cell subsets in IgM mesangial proliferative glomerulonephritis. A comparative study with minimal change nephrotic syndrome and immunonegative mesangial proliferative glomerulonephritis.

Glomerular and interstitial leukocyte subpopulations were analyzed in renal biopsies from 18 patients with IgM mesangial proliferative glomerulonephritis (IgM MPGN), 19 patients with minimal change nephrotic syndrome (MC) and 10 patients with immune-negative mesangial proliferative glomerulonephritis (IN MPGN), by immunoperoxidase techniques with monoclonal antibodies. Mesangial cell proliferation was strongly correlated with absolute numbers of intraglomerular T lymphocytes (r = 0.71; p < 0.01) in IgM MPGN, but not in MC or IN MPGN. Significant differences were found in the numbers of macrophages, CD4- and CD8-positive glomerular cells (Student's t test p < 0.01, 0.05 and 0.01, respectively) in IgM MPGN, but not in MC or IN MPGN. The numbers of CD45-, CD3- and CD8-positive cells also differed in each patient group (ANOVA p < 0.01, 0.05 and 0.05, respectively), the greatest and smallest values appearing in IgM MPGN and MC, respectively. Multiple regression test showed initial proteinuria values in IgM MPGN to be closely dependent on the density of neutrophils, macrophages, T and B lymphocytes and CD4 cell inflammatory infiltrates (r2 = 0.92; p < 0.01). At the end of the follow-up, proteinuria in IgM MPGN, but not in MC or IN MPGN, was dependent on T cell infiltrate (r2 = 0.97; p < 0.01). Our findings suggest that proteinuria in IgM MPGN results from local mesangial damage rather than from the effects of a soluble circulating factor, as has been proposed for MC. The clinical and immunohistochemical differences observed between these two processes support the notion that they should be considered as separate entities.

Adult↗
PubMed1991

Diffuse sclerosing papillary carcinoma of the thyroid gland: immunohistochemical analysis of the local host immune response.

Surgical specimens from four patients with diffuse sclerosing papillary carcinoma of thyroid were examined by electronmicroscopy. In addition, immunohistochemical examination using a panel of monoclonal and polyclonal antibodies was carried out in order to investigate the expression of HLA-DR antigen, the presence of Langerhans' cells and the phenotypic characteristics of the inflammatory infiltrate. The ultrastructural study showed that the intraglandular dissemination, typical of this tumour, was due to massive lymphatic invasion. Many Langerhans' cells were observed among tumour cells and in the lymphoid infiltrates in proximity to tumour foci. HLA-DR expression was seen on macrophages, Langerhans' cells, endothelial cells, lymphoid cells, many tumour cells and in some non-neoplastic follicles close to tumour clusters and lymphoid infiltrates. The immunohistochemical analysis of the inflammatory infiltrates showed a high proportion of B- and T-cells, and moderate numbers of plasma cells. Our results suggest that the tumour-specific immune response can give rise to an autoimmune reaction involving non-neoplastic follicles. It is suggested that this could be one of the mechanisms responsible for immunofacilitation of tumour growth.

Adolescent↗
PubMed1989

Blue nevus of the maxillary sinus. An immunohistochemical and electron microscopic study.

We studied a case of blue nevus of the maxillary sinus by immunocytochemical and electron microscopic techniques. Blue nevus has not been reported previously to occur in the maxillary sinus. The melanocytic nature of this lesion was established based upon the ultrastructural demonstration of pre- and melanosomes, and the presence of S100 protein immunoreactivity in the pigmented cells. Histogenetic aspects of the blue nevus of the maxillary sinus are discussed and an origin in multipotential undifferentiated cells is postulated.

Adult↗
PubMed1988

Hamartomatous solitary polyp with malignant progression in the jejunum. A histochemical and immunohistochemical study by light and electron microscopy.

A case of solitary hamartomatous jejunal polyp with adenomatous and carcinomatous changes in a 16-year-old girl is reported. In the hamartomatous polyp, neutral and acid non-sulfate mucosubstance was detected, principally in goblet cells; carcinoembryonic antigen was demonstrated on the surfaces of the microvilli and luminal border of the crypts and glands; absorptive columnar, goblet, argentaffin, argyrophil and Paneth cells were evident. The adenomatous and, mainly, the carcinomatous areas revealed a decreased amount of mucosubstance and a variable degree of positive intracytoplasmic staining for carcinoembryonic antigen. With electron microscopy, the adenomatous areas showed columnar absorptive cells and mucus-secreting goblet cells; also immature columnar cells were observed in the dysplastic zones. To our knowledge, this is the first study to document the histochemical, immunohistochemical and ultrastructural features of a hamartomatous polyp with neoplastic transformation.

Adolescent↗
PubMed1986

Lymphangioma of the duodenum: an ultrastructural study.

Two cases of duodenal lymphangioma were diagnosed by endoscopy, and light and electron microscopic findings are reported. Ultrastructural studies showed smooth muscle cells around lymphatic vessels, and amyelinic nerve fibers and smooth muscle cells in the interstitium. On the basis of the ultrastructural features, a hamartomatous rather than tumoral origin is suggested for the duodenal lymphangioma. Lymphangiectatic cysts of Letulle and lymphangiectasia are discussed in the differential diagnosis. Submucosal lymphangiomas of the small bowel might be considered lymphangiectatic cysts.

Adult↗
PubMed1986

Primary small cell carcinoma of skin. Histogenetical study.

Four cases of primary small cell carcinoma of the skin (PSCCS) are presented (ages ranging from 60 to 68 years). Ultrastructurally, two cell types were identified, with both presenting electron-dense secretory granules and paranuclear intermediate filaments. Argyrophylia was positive in one case. Intense solar elastosis in two cases and actinic keratosis in one case suggest a possible role from solar damage in the pathogenesis of this tumor. According to comparative ultrastructural features, different histogenetic possibilities in Merkel cells (MC), peripheral neuroblastic tissue, and totipotential cells are discussed. Some neurosecretory-like granules were observed in basal cell carcinoma (BCC). We consider that PSCCS reproduces cells similar to MC and probably originates in stem cells with totipotential capacity.

Aged↗
PubMed1982

Epithelioid leiomyoma of the vulva.

An ultrastructural and light-microscopic study of the second published case of epithelioid leiomyoma of the vulva is reported. The tumor occurred in the right labium minus of a 26-year-old nonpregnant female. Optic microscopy revealed a clear cell neoplasm with a marked relationship to arterial vessels from which it may originate. The ultrastructure was analogous to that of similar cases reported in the uterus and stomach.

Adult↗