Partial purification of a protein growth inhibitor from multicellular spheroids.

We report the partial purification of growth inhibitors extracted from human and mouse multicellular tumor spheroids with extensive necrosis. Sephadex G-100 column chromatography of spheroid extracts separated inhibitory fractions which eluted just after the void volume of the column. Identical chromatography of monolayer cell extracts showed no inhibitory activity. High-performance liquid chromatography of spheroid extracts separated single active peaks at apparent molecular weights of 80-89 kD. These extracts were extremely heat labile, and activity was destroyed by moderate trypsin treatment. The isolation of similar growth inhibitors from spheroids of two cell lines suggests that inhibition is important in tumor cell growth control in a three-dimensional situation.

[Diabetic neuropathy. II. Autonomic neuropathy. The gastrointestinal system]. / La neuropatia diabetica. II. Neuropatia autonoma. Apparato gastroenterico.

Autonomic diabetic neuropathy of the alimentary canal takes several basic forms: a) oesophagopathy , b) gastroparesis, c) enteropathy, d) bile duct disorders. In many cases three are no subjective symptoms. In other the onset of the clinical condition may take acute and dangerous forms as in gastropathy. In still other cases e.g. enteropathy, the neuropathy may develop in bizarre and unexpected ways which are highly damaging to the patient's quality of life though in most cases they are not fatal. Bile disorders involving minimal motility after stimulus, as in denervation and reduced sensitivity to pain are particularly significant. Diabetics are more likely to suffer from calculosis (59.6% of cases), with septic complications (20% in diabetics compared to 7.8% in non-diabetics) or cholestasis (20% in diabetics v. 15.8% in non-diabetics). These figures indicate that all diabetics and especially the elderly should be subjected to careful examination to identify any bile disorders.

[Diabetic neuropathy. I). Peripheral neuropathy]. / La neuropatia diabetica. I). Neuropatia periferica.

This is the first of a series of reports on diabetic neuropathy. Peripheral or somatic diabetic neuropathy is discussed with reference to its major symptoms: central, peripheral and amyotrophic mononeuropathies, symmetrical and asymmetrical polyneuropathies, peripheral arthropathy and finally diabetic cachexia. The various theories on the pathogenesis of peripheral neuropathy are presented. Finally data on 173 type I and II diabetics are presented. These patients, treated in outpatients departments, were paired by sex, weight and age with an equal number of non-diabetic subjects. The results of the survey largely confirm report in the literature. The importance of continuous medical surveillance for the identification and hence prevention of diabetic neuropathy is emphasized. This is particularly necessary since we have still much to learn about the natural history of the disease and for the moment the therapeutic approaches to the various neuropathies concerned are both tentative and symptomatic.

[Plasma renin activity in hypertensive patients under basal conditions and in various postures: preliminary data]. / Attivita' reninica plasmatica in ipertesi in condizioni basali ed in postura: dati preliminari.

We have studied PRA levels in 10 healthy subjects compared with 10 patients affected with essential hypertension (with low PRA) on venous blood samples collected after 8 hours of rest and after 15-20 minutes of slow plain walk. Contemporarely we have taken up arterious pression levels in each class of subjects of these studies. No significant differences of PRA are demonstrable in healthy subjects and in patients affected with essential hypertension. Postural changes in hypertension produces significant rise of PRA, not related to arterial pressure.

[Oxoprenolol and plasmatic renin activity in essential hypertension: preliminary data]. / Oxoprenololo ed attività reninica plasmatica nell'ipertensione essenziale: dati preliminari.

We have studied PRA levels in 10 healthy subjects compared with 10 patients affected with essential hypertension (with low PRA) on venous blood samples collected after 8 hours of rest and after 15-20 minutes of slow plain walk and 15 minutes after intravenous administration of oxoprenolol (mg 2). Contemporarely we have taken up arterious pression levels in each class of subjects of these studies. Postural changes produces significant rise of PRA in subjects affected with essential hypertension, that is significantly inhibited by pharmacologic interference produced by beta-blocking agents. This occurrence is independent of arterial pressure changes.

The isolation from ribonucleic acid of substituted uridines containing alpha-aminobutyrate moieties derived from methionine.

The RNA of an established line of Chinese hamster cells growing in cell culture contains a small number of uridines substituted at the 3-position with a gamma-linked alpha-aminobutyrate residue. Structure has been ascertained by: (a) examination of incorporation of isotopic labels from precursors; (b) degradation with anhydrous hydrazine and comparison of the products with synthetic material or with hydrazinolysis products of known uridines; and (c) comparison of the unknowns as their hydantoin derivatives with the 5-beta-(bromoethyl)hydantoin alkylation products of uridine and of 1- and 3-methylpseudouridine. In this manner it is shown that 18-S RNA of ribosomes contains a single residue of a nucleoside which we tentatively identify as 1-methyl-3-gamma-(alpha-amino-alpha-carboxypropyl)pseudouridine per molecule. RNA isolated from the supernatant fraction, sedimenting at 4 S and co-electrophoresing with transfer RNA on polyacrylamide gels, contains several similar bases, one of which is identified as 3-gamma-(alpha-amino-alpha-carboxypropyl)uridine. Each of the above nucleosides derives its alpha-aminobutyrate residue from methionine.

RNA synthesis in Chinese hamster cells. I. Differential synthetic rate for ribosomal RNA in early and late interphase.

The incorporation of methionine-methyl-(14)C into 18S ribosomal RNA of cultured Chinese hamster ovary cells in early and late interphase has been determined by zone-sedimentation analysis of phenol-extracted RNA preparations. Synchronized cell cultures were prepared for these studies by thymidine treatment and by mechanical selection of mitotic cells. The specific activity of 18S RNA labeled in late interphase was found to be 1.1-1.2 times that of 18S RNA labeled in early interphase. Upon correction for increase in RNA mass, the rate of methylation of 18S RNA in late interphase is about 1.9 times that in early interphase.