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Biomedical subjects

M Grieco

Publications and source records attributed to M Grieco.

At least 55 records · Page 3Linked to original sources
PubMed1988

A retrovirus carrying the polyomavirus middle T gene induces acute thrombocythemic myeloproliferative disease in mice.

Mice inoculated with an artificially constructed retrovirus carrying the middle T gene of polyomavirus develop acute myeloproliferative disease with severe thrombotic and hemorrhagic disorder and impaired platelet function. The megakaryocytic lineage appears to be a target for polyoma-murine leukemia virus infection and middle T gene expression. This newly described disease represents a unique model system for studying disorders of the megakaryocytic lineage.

Adenosine Triphosphate↗
PubMed1988

Cooperation between the polyomavirus middle-T-antigen gene and the human c-myc oncogene in a rat thyroid epithelial differentiated cell line: model of in vitro progression.

Two rat thyroid epithelial differentiated cell lines, PC Cl 3 and PC myc, were infected with the polyoma murine leukemia virus (PyMLV) carrying the Middle-T-antigen gene of polyomavirus. After infection, both cell lines acquired the typical markers of neoplastic transformation; however, the PC myc cells showed a greater malignant phenotype. Furthermore, the thyroid differentiated functions were completely suppressed in PC myc cells transformed by PyMLV, whereas they were, at least partially, retained in PC Cl 3 cells transformed by PyMLV, and in particular, thyroglobulin synthesis and secretion were not affected at all. Since no differences in the expression of the middle-T-antigen gene were observed in the two PyMLV-transformed cell lines, the different properties shown by these two infected cell lines must be ascribed to the expression of the c-myc oncogene.

Animals↗
PubMed1987

One- and two-step transformations of rat thyroid epithelial cells by retroviral oncogenes.

A system of epithelial cells is described in which it is possible to study the number and the nature of genes capable of conferring the malignant phenotype. Two fully differentiated, hormone-responsive cell lines from rat thyroid glands are presented which are susceptible to one-step or two-step transformation upon infection with several murine acute retroviruses. After infection, both cell lines became independent from their thyrotropic hormone requirement for growth. However, complete transformation was achieved with one of the cell lines (FRTL-5 Cl 2), whereas the other cell line (PC Cl 3) failed to grow in agar and to give rise to tumors in vivo. The latter cell line was susceptible to complete transformation upon cooperation of the v-ras-Ha and the human c-myc oncogenes.

Animals↗
PubMed1984

Central-nervous-system toxoplasmosis in homosexual men and parenteral drug abusers.

Central-nervous-system toxoplasmosis developed in 7 of 269 patients with the acquired immunodeficiency syndrome reported to the New York City Health Department through July 1982. Focal neurologic abnormalities, mass lesions on computed-tomographic brain scans, lymphocytic cerebrospinal fluid pleocytosis, and detectable IgG antibody to Toxoplasma gondii were common; but IgG titers of 1:1024 or more, IgM antibody to T. gondii, and positive open brain biopsies were uncommon. Serologic findings suggested that the disease resulted from recrudescent rather than primary infection. Four of five patients improved when treated with sulfonamides and pyrimethamine, but 2 had relapses. An aggressive diagnostic approach and sometimes even empiric therapy are warranted when central-nervous-system toxoplasmosis is suspected in a seropositive patient with the acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Inhibition of dimethyl sulfoxide-induced differentiation of Friend erythroleukemic cells by 5'-methylthioadenosine.

5'-Methylthioadenosine is a sulfur-containing nucleoside derived from the metabolism of polyamines which is known to exert an antiproliferative effect on several cell systems in vitro, including the Friend leukemia cell system. We have investigated the role of 5'-methylthioadenosine on the dimethyl sulfoxide-induced differentiation of this system. At a concentration of 400 microM, the drug strongly inhibited (80%) the induced differentiation of Friend cells, and this effect was already observable at a concentration as low as 10 microM (36% inhibition), as evidenced by the benzidine staining procedure and by the dot-blot hybridization of globin mRNA with a human beta-globin probe. Similar results have been obtained by using 5'-S-isobutylthioadenosine, which is a synthetic structural analogue of 5'-methylthioadenosine. The block of differentiation produced by these nucleosides was not mediated by adenine (a catabolite of both molecules) and was not reverted by spermine or spermidine, the two polyamines whose synthesis is inhibited by 5'-methylthioadenosine. We report a decrease of the aminopropyltransferases activities (the enzymes responsible for 5'-methylthioadenosine biosynthesis) in dimethyl sulfoxide-treated Friend cells, which could lead to a decrease of the intracellular content of 5'-methylthioadenosine during the erythroid maturation of Friend cells. The results obtained are consistent with the hypothesis that 5'-methylthioadenosine may act as an endogenous regulator of Friend cell differentiation.

Adenosine↗
PubMed1984

Closure of the interventricular foramen and morphogenesis of the membranous septum and ventricular septal defects in the human heart.

The development of the atrioventricular and interventricular membranous septum was studied The interventricular foramen is closed by the growth of the endocardial crest of the interventricular muscular septum towards the cranio-ventral atrioventricular cushion and towards the part B of the outflow tract ridge B-3; the bulbus is septated by the apposition and fusion of parts A and B of the outflow tract ridges A-1 and B-3. The membranous septum develops from the crest of the interventricular muscular septum between the interventricular muscular septum and the right border of the atrioventricular cushions, where it forms the atrioventricular mesenchymal septum. This last develops towards the right surface of the interventricular muscular septum and forms the septal cusp primordium of he tricuspid valve; this is undermined, for which reason the septal cusp is cut off from the interventricular muscular septum at the 5th month of fetal life. From the 6th month of intrauterine life, the undermining extends to the atrioventricular mesenchymal septum, for which reason the right septal cusp becomes inserted in the right face of the atrioventricular mesenchymal septum which becomes divided into atrioventricular and interventricular. The Authors advance some hypotheses as to the origin of certain defects of the interventricular septum.

Animals↗
PubMed1980

A further contribution to the development of the aortopulmonary septum in rabbit embryos.

In rabbit embryos, the bulbar spiral endocardial ridges A-1 and B-3 develop by the moulding action of the intraheart bloodstreams ininterruptedly from the ventricular extremity to the IV and VI branchial arterial arches. Cellular basophilia is stronger where the endothelium cells and the endocardial cushion tissue cells proliferate actively and, therefore, the bulbar spiral endocardial ridges fuse and form the aortopulmonary septum.

Animals↗
PubMed1976

Beclomethasone dipropionate aerosol in the treatment of chronic bronchial asthma.

In a double-blind, randomized study, 93 corticosteroid-independent patients with chronic bronchial asthma were treated with either beclomethasone dipropionate aerosol at 400 mug per day of its vehicle for 4 wk to determine and compare the effectiveness and safety of the preparations. Evaluations made before, at weekly intervals during, and 1 wk after treatment indicated that beclomethasone dipropionate aerosol was superior to its vehicle is improving FVC, FEV1, FEF25%--75%, and clinical signs and symptoms, and in the overall evaluations by both the investigators and the patients. Plasma cortisol levels measured at the end of the second and fourth weeks were not substantially different from those before treatment in either group. No significant side effects or abnormalities in laboratory results were noted.

Adolescent↗
PubMed1975

Reduction in T-lymphocytes forming active rosettes in chronic marijuana smokers.

Rosettes formed by peripheral T- and B-lymphocytes were studied in 23 normal controls and 23 marijuana smokers. The mean percentage of cells forming B type rosettes were normal in both groups. The percentage of T cells forming rosettes was lower in the marijuana smokers, and 39% had values below 2 standard deviations of the mean of the normal control group. These observations suggest some alteration in some T cells in some marijuana smokers.

Adolescent↗
PubMedDate not supplied

A new oncogene in human thyroid papillary carcinomas and their lymph-nodal metastases.

Using DNA transfection analysis on NIH 3T3 cells, activated human oncogenes have been isolated from a variety of fresh solid tumours. Thyroid neoplasias show a wide range of lesions varying from slowly progressive well-differentiated tumours to anaplastic highly malignant neoplasms. Therefore they represent an attractive model to investigate the role of oncogene activation in different stages of the neoplastic state. Here we report the detection of transforming activity in DNAs extracted from five thyroid papillary carcinomas and two of their respective lymph-nodal metastases.

Animals↗
PubMedDate not supplied

Beta- and gamma-catenin expression in oral squamous cell carcinomas.

Cell-cell adhesion is mediated by cadherins (integral membrane proteins) which form a complex with catenins (cytoplasmatic proteins). Down-regulation of cadherins and more recently of catenins has frequently been detected in many types of human carcinomas, in which it has been associated to tumor progression. While E-cadherin expression has been extensively studied in many forms of human cancers, including oral SCC, less is known about the expression levels of catenins in oral SCCs. The objective of this study was to evaluate the role of these proteins in the carcinogenetic process of the oral cavity. We evaluated by immunohistochemistry beta- and gamma-catenin expression in 30 cases of intraoral squamous cell carcinomas at different degree of cellular differentiation. As already reported for E-cadherin, the beta- and gamma-catenin expression showed an inverse relationship with the degree of differentiation, being the membranous expression of both catenins homogeneously reduced in less differentiated oral squamous cell carcinomas (grade 3). More interestingly, a decreased expression of these molecules was also found at the invasive front of grade 2 and sometimes of grade 1 carcinomas, thus suggesting a more aggressive biological behavior of these cancer cells. An absent staining for both beta- and gamma-catenins could constitute a hallmark of aggressive biological behavior even in tumor still well or moderately differentiated, at least in the peripheral invading front constituted by less differentiated tumor cells.

Adult↗
PubMedDate not supplied

Effects of stress on adrenal steroidogenesis blockade by aminoglutethimide.

After one week of AG-treatment, the adrenal cortex reveals a marked storage of lipids and cholesterol, as well as a decrease in haematic corticosterone and progesterone levels. On the contrary, when AG-treatment is associated with stress, an increase in plasma corticosterone and progesterone levels occurs, together with a less evident lipidic storage in the adrenal cortex. These results seem to indicate the possibility that, during stress, hypothalamo-hypophysis axis activation is able to remove, at least partially, the adrenal biosynthesis blockade operated by AG-administration.

Adrenal Cortex↗