Effects of chronic treatment with ACTH on the intracellular levels of cyclic-AMP and cyclic-GMP in the rat adrenal cortex

The effects of chronic ACTH treatment on the increase in the intracellular concentration of cyclic-AMP and cyclic-GMP acutely elicited by ACTH in the rat adrenal cortex were investigated. The results are consistent with the hypothesis that chronic ACTH treatment stimulates a) the de novo synthesis of adenylate- and guanylate-cyclase or b) the synthesis of new specific membrane receptors for ACTH.

[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.

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.

Investigations into the effects of ACTH on the half-life of mitochondrial proteins in the rat adrenal cortex

ACTH elongates the half-life of the mitochondrial proteins from the rat adrenal cortex, and chloramphenicol inhibits this effect of ACTH. The hypothesis is advanced that the ACTH-provoked stabilization of the adrenocortical mitochondrial proteins requires continuous mitochondrial DNA-dependent protein synthesis.

[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.

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.

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.

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.

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.

Induced degradation of glycosaminoglycans in Hurler's and Hunter's syndromes by plasma infusion

The effects of the administration of normal human plasma to patients affected by mucopolysaccharidoses I and II (Hurler's and Hunter's syndromes) have been evaluated. The infusion was followed by a decreased urinary excretion of relatively large molecular weight glycosaminoglycans and by an increased excretion of their products of degradation. Among the latter, products of the degradation of dermatan sulfate and heparan sulfate could be demonstrated. The results indicate that normal human plasma may contain those "factors" that are involved in the normal degradation of dermatan sulfate and heparan sulfate, that are missing in the diseased states.