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Biomedical subjects

G Neri

Publications and source records attributed to G Neri.

At least 343 records · Page 19Linked to original sources
PubMed1978

[Malignant insuloma. Evaluation of the response to treatment with streptozotocin, using selective arteriography of the celiac axis].

A patients with metastatic insulin-producing islet-cell carcinoma has been treated with Streptozotocin intravenously and studied by selective celiac angiography during treatment. A 50% decrease of the tumor's size has been demonstrated by this technique after a total dose of 19 grams of the drug together with return to normal of the serum-insulin and blood-glucose values. The usefulness of angiography in evaluating the tumor response to Streptozotocin and in managing chemotherapy is discussed.

Adenoma, Islet Cell↗
PubMed1978

Investigations into the mechanism of hormone release by rat adrenocortical cells.

Vinblastine treatment blocks corticosterone release from rat adrenal zona fasciculata without impairing hormone synthesis, and induces the formation of acid phosphatase-positive granular clumps at the juxta-sinusoidal pole of the cells. Autoradiography shows that ACTH administration to vinblastine-treated animals mobilizes the 3H-cholesterol stored in the lipid droplets and leads to a noticeable labelling of the granular clumps. The possible significance of these granules is discussed.

Adrenal Cortex↗
PubMed1978

Behavior of a cell line derived from a mouse submaxillary adenocarcinoma during the initial 480 days in vitro.

A cell line was established from a transplantable adenocarcinoma, containing viral particles of the A and B type, drived from a tumor appearing spontaneously in the submaxillary region of a male mouse of the C3H/He strain. This line, after 480 days in vitro, did not change the original epithelial-like morphology, the viral expression, the membrane immunofluorescence and the degree of agglutination by various plant lectins. After 208 days of culture, the presence of up to 3 pairs of metacentric chromosomes appeared in about 55% of the cells. However, this change in the chromosomal pattern was not sufficient, at least within the limits of our observation, to modify significantly the other parameters investigated, with the possible exception of the oncogenicity, which showed a modest decrease after 296 days of culture.

Adenocarcinoma↗
PubMed1978

Investigations on the turnover of adrenocortical mitochondria. X. A correlated biochemical stereological study of the effects of chronic treatment with chloramphenicol on the mitochondria of the rat zona fasciculata.

The effects of chloramphenicol (CAP) on rat adrenocortical cells were investigated by biochemical and stereological methods. It was found that administering 50mg/kg of CAP every 12 hours provoked a persistent inhibition of the incorporation of 3H-leucine into mitochondrial proteins. Chronic treatment (up to 15 consecutive days) with this dose of CAP induced a significant decrease in the volume of the mitochondrial compartment, in the surface area of the outer and inner mitochondrial membranes and in the number of mitochondria per cell. These results confirm the hypothesis that the ACTH-induced maintenance of adrenocortical mitochondrial growth requires continuous mitochondrial DNA-dependent protein synthesis.

Adrenal Cortex↗
PubMed1978

Investigations on the turnover of adrenocortical mitochondria. XII. Studies on the mechanism of the ACTH-induced elongation of the half-life of rat zona fasciculata mitochondria.

The half-life of rat adrenocortical mitochondria was determined by high resolution autoradiography and liquid scintillation spectroscopy as previously described (Mazzocchi et al., '76). The results obtained by the two approaches were in good agreement. In the normal rats the half-life of adrenocortical mitochondria averaged 11 days. ACTH significantly increased mitochondrial half-life to about 16 days, and chloramphenicol significantly decreased this parameter in both untreated and ACTH-administered rats to about seven days. It is suggested that the ACTH-induced maintenance and slowing down of the degradation rate of adrenocortical mitochondria requires continuous mitochondrial DNA-dependent protein synthesis.

Adrenal Cortex↗
PubMed1978

Studies on the persistence of differentiated functions in rat hepatocytes set into primary tissue culture. II. Production of specific exportable proteins and the effect of purine cyclic nucleotides: an immunofluorescent study.

Immunofluorescent studies showed that even after 15 days in vitro primary neonatal rat hepatocytes contained in their cytoplasm detectable amounts of different adult rat serum proteins, including fibrinogen and proalbumin. Estimation of the intensity of specific fluorescence revealed that in untreated cultures the hepatocytic content of the various exportable antigens progressively diminished between the 5th and 15th day in vitro. Treatment with cAMP (10(-5) M daily) alone increased in hepatocytic cytoplasm, with respect to parallel controls, the content of total exportable proteins and of proalbumin. Daily administration of an equimolar association (10(-5) M) of cAMP with cGMP increased the total protein, proalbumin and fibrinogen content of hepatocytes. Daily treatment with cGMP (10(-5) M) alone caused only light and transitory increases in the content of proalbumin and fibrinogen. Rocket immune electrophoresis showed that the hepatocytic secretion of specific proteins into the growth medium persisted up to the 15th day, although progressively diminishing in intensity. The secretion of total exportable proteins and of albumin, but not of fibrinogen, was stimulated by cGMP used alone or coupled with equimolar cAMP.

Cell Differentiation↗
PubMed1977

Investigations on the turnover of adrenocortical mitochondria. XI. Effects of dexamethasone on the half-life of mitochondria from the rat zona fasciculata.

The effects of dexamethasone on the half-life of rat adrenocortical mitochondria were investigated by high resolution autoradiography and liquid scintillation spectroscopy. According to the method employed, the half-life averaged 11.27 and 10.46 days. Dexamethasone was found to decrease significantly this parameter (to about 5 days). Since dexamethasone-treated rats can be regarded as pharmacologically hypophysectomized animals, the data indicates that ACTH is involved in the maintenance of the half-life of adrenocortical mitochondria.

Adrenal Cortex↗
PubMed1977

[Effectiveness of cystolusis with rifamycin SV in patients with permanent catheters].

It has tested the effect of Rifamicina SV in the cystolusis employed on patients with permanent catheter: compared to the treatment with physiological solution this one, with Rifamicina SV, has showed, in most cases, the lower incidence of urine bacteria and their quick negative answer. This by an only local theatment. During the experiment has also been showed the possibility for the Rifamicina SV of selecting the Citrobacter as a resistant bacterial species.

Bacterial Infections↗
PubMed1976

Investigations on the turnover of adrenocortical mitochondria. V. An autoradiographic study of the radioactivity decay in the mitochondrial compartment from the adrenal cortex of 3H-thymidine-injected rats.

The radioactivity decay of the mitochondrial compartment of 3H-thymidine-injected rats was followed by high resolution autoradiography. The number of days in which the radioactivity of the mitochondrial compartment is reduced to a half was calculated from the semilogarithmic plots of radioactivity versus time. Since DNA is a very stable molecule, it was assumed that this parameter can be an estimate of the half-life of adrenocortical mitochondria. It was found that the half-lives of mitochondria from the zonae glomerulosa, fasciculata and reticularis are, respectively, 8.20, 11.51 and 8.16 days.

Adrenal Cortex↗
PubMed1976

Effect of neuraminidase and papain treatment on lectin-induced agglutination of Novikoff tumor cells and assay of lectin receptor activity of the glycopeptides released from the cell surface by papain.

Lectins, plant proteins that bind specific saccharide determinants, have been utilized to examine the effect of neuraminidase digestion on the structure and/or expression of oligosaccharide moieties present at the periphery of Novikoff ascites hepatoma cells. Five lectins were utilized: concanavalin A (Con A), specific for alpha-D-manno- or alpha-D-glucopyranosyl residues; wheat germ agglutinin, specific for 2-acetamido-2-deoxy-D-glucopyranosyl residues; Ricinus communis agglutinin I (RCAI), specific for D-glucopyranosyl residues; R. communis agglutinin II (RCAII), specific for D-galacto- or 2-acetamido-2-deoxy-D-galactopyranosyl residues; and soybean agglutinin, specific for 2-acetamido-2-deoxy-D-galactopyranosyl residues. Neuraminidase treatment of Novikoff cells did not alter their agglutination by Con A or wheat germ agglutinin. Similar treatment produced only a 2-fold increase in their agglutination by RCAI but a 12-fold increase in their agglutination by RCAII, indicating that 2-acetamido-2-deoxy-D-galactopyranosyl residues become expressed upon neuraminidase treatment. This conclusion was confirmed by the observation that neuraminidase-treated Novikoff cells acquired agglutinability by soybean agglutinin. Binding studies using ferritin-conjugated RCAII indicated that neuraminidase treatment exposed cryptic cell surface receptors for RCAII. To ascertain the role of cell surface glycoproteins in lectin-induced agglutination of Novikoff cells, glycopeptides cleaved from the cell surface by papain were assayed for lectin receptor activity. The cell surface glycopeptides exhibited receptor activity for Con A, wheat germ agglutinin and RCAI but not for RCAII and soybean agglutinin. A cell surface macrosialoglycopeptide fraction, resolved by gel filtration and ion-exchange chromatography, possessed a major portion of the Con A and RCAI receptor activity.

Agglutination↗
PubMed1975

Viral expression, oncogenicity, and antigenicity of a mouse salivary gland tumor and two cell lines derived from it.

An in vitro cell line (SGT) derived from a mouse submaxillary gland adenocarcinoma (TGS) containing A and B viral particles maintained its oncogenicity only for newborn isogeneic hosts (C3H/He mice) immunosuppressed with antithymocyte serum. Inoculation into adult isogeneic animals did not cause tumor but provided partial protection against a challenge with TGS cells. The loss of oncogenicity for nonimmunosuppressed isogeneic hosts was accompanied by the acqusition of oncogenicity for adult, nonimmunosuppressed, xenogeneic hosts (golden hamsters) given subcutaneous inoculations of SGT cells on the back. From the tumor grown in the hamster, which is histologically similar to the original tumor of the mouse, an in vitro cell line (HWS) was derived. The comparative analysis of the 2 cell lines, SGT and HWS, led to the following conclusions: (a) the karyological pattern of the 2 cell lines in virtually the same; (b) the cell surface antigenic pattern is similar for the 2 cell lines, as determined by colony inhibition test and cytotoxicty test; (c) the cells of the HWS line behave serologically as a mouse-hamster hybrid, also as determined by colony inhibition and cytotoxicity tests; (d) both cell lines have only intracytoplasmic viral particles of the A type; and (e) agglutination with the plant lectins concanavalin A and wheat germ agglutinin occurs at lower concentrations of agglutinin for HWS cells than for SGT cells.

Adenocarcinoma↗