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Biomedical subjects

A Locatelli

Publications and source records attributed to A Locatelli.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Cyclic AMP phosphodiesterase activity in Fasciola hepatica (L.) homogenates.

The authors have studied the bahaviour of cyclic 3',5'-AMP phosphodiesterase in the 2,000 g supernatant of the Fascilola hepatica homogenate, under basal conditions and after addition of various substances. Dopamine remarkably inhibits the enzyme activity, imidazole causes a strong activation, while serotonin, theophylline, PGE1 and PGF2alpha appear to be ineffective.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

Synthesis and antitumor activity of substituted 3-(5-imidazo[2,1-b]thiazolylmethylene)-2-indolinones.

The synthesis of 3-(5-imidazo]2,1-blthiazolylmethylene)-2-indolinones, analogs of compounds recently published, is described. The EIZ isomerism was studied by means of nuclear Overhauser effect experiments and X-ray crystallography. All the compounds were tested as potential antitumor agents. They were also tested as potential inhibitors of cyclin-dependent kinase 1 (CDK1), in order to determine if the antitumor activity was related to this mechanism of action. The results showed that under certain substitution conditions (5-methoxy group for the indole benzene ring and 2-methyl group for the imidazothiazole system), an interesting antitumor activity was found for some compounds. From the analysis of the antitumor data, 3-1(2,6-dimethylimidazo[2,1-bJ-thiazol-5-yl)methylenel-5-methoxy-2-indolinone was the most active of the whole series.

Animals↗
PubMedDate not supplied

Influence of age and cortisone treatment on two intestinal lysosomal hydrolases in young rats.

The effects of cortisone acetate injected i.p. on acid phosphatase and beta-glucuronidase in the small intestine mucosa of two groups of rats aging 12-14 and 20-22 days are reported. The following results are obtained: a) Total and free activities of the two enzymes show age-dependent differences. b) Cortisone acetate causes a very marked decrease of the enzymic activities only in the younger rats while being ineffective on the older ones. c) The kinetics of the enzyme release at 37 degrees C appear independent either of age or of cortisone injection. d) The "in vitro" lysosome labilizing treatments are ineffective.

Acid Phosphatase↗
PubMedDate not supplied

Effects of experimental cryptorchidism and subsequent orchidopexy on seminiferous tubule functions in the lamb.

The reversibility of damage caused by cryptorchidism to the seminiferous tubules of the lamb was investigated at various ages. Lambs were made bilaterally cryptorchid either at birth or at 2 months of age. Then orchidopexy was performed at either 2 or 4 months of age. In permanently cryptorchid lambs, spermatogenesis stopped completely, and Sertoli cell function, as measured by FSH receptors, androgen receptors and ABP, was much reduced (-96%, -86% and -81%, respectively). Orchidopexy allowed the cryptorchid seminiferous epithelium to grow again, but the more differentiated the germ cells, the less they were capable of restoration. Even in 0- to 2- and 0- to 4-month-old temporarily cryptorchid lambs that had recovered normal Sertoli cell function, 16 to 49% of the tubules still were empty. It was concluded that cryptorchidism irreversibly damages the seminiferous tubules at a level other than the hormone receptors.

Age Factors↗
PubMedDate not supplied

Antitumor and cardiotonic activity of imidazo[2,1-b]thiazole guanylhydrazones.

A number of imidazo[2,1-b]thiazole guanylhydrazones, whose antitumor activity has already been described, were tested as potential cardiotonic agents. The guanylhydrazone of 2,3-dihydro-6-chloroimidazo[2,1-b]thiazole-5-carboxaldehyde (2a) was the most interesting compound showing both antitumor and cardiotonic activity.

Animals↗
PubMedDate not supplied

Synthesis of imidazo[2,1-b]thiazoles and thiazolines as potential antiulcer agents.

The replacement of the imidazole ring of cimetidine with a bicyclic system (imidazo[1,2-a]pyridine), reported in the literature, produced compounds endowed with potent antiulcer activity. In this paper we describe the synthesis of imidazo [2,1-b]thiazoles and thiazolines bearing the side chain of metiamide, cimetidine and ranitidine: the compounds obtained, tested on gastric lesions induced in rats by ethanol and by stress, were devoid of antiulcer activity.

Animals↗
PubMedDate not supplied

Potential antitumor agents. XXII. Synthesis and cytotoxic activity of imidazo [2,1-b]thiazole adamantylthioureas.

A series of imidazo[2,1-b]thiazole adamantylthioureas (3a-f) was synthesized by reaction of the methylsulfanylethylamines 2a-f (prepared in turn from the hydroxymethylimidazo[2,1-b]thiazoles 1a-f and cysteamine) with 1-adamantylisothiocyanate. 1-Adamant-1-yl-3-[2-(6-chloro-2,3- dihydroimidazo[2,1-b]thiazol-5-ylmethylsulfanyl)ethyl] thiourea (3d) was significantly active.

Animals↗
PubMedDate not supplied

Platelet composition and function in patients undergoing cardiopulmonary bypass for heart surgery.

BACKGROUND: Previous studies showed severe biochemical and functional damage to platelets in patients undergoing cardiopulmonary bypass for cardiac surgery, and suggested that this derived from the proteolytic action of plasmin on the platelet surface. METHODS: A double-blind study was carried out to compare platelet function and composition in patients randomized to receive the protease inhibitor aprotinin or placebo during reoperation for valvular prosthesis replacement or coronary artery bypass grafting. RESULTS: Flow cytometry with specific monoclonal antibodies and polyacrylamide gel electrophoresis did not show any significant proteolysis of platelet glycoprotein Ib and IIb-IIIa either in the placebo or the aprotinin group. Functional studies were consistent with these results, since ristocetin-induced platelet agglutination was unchanged and platelet aggregation and ATP release induced by collagen and ADP were only slightly reduced by cardiopulmonary bypass. These mild defects in platelet function were partially prevented by aprotinin infusion. CONCLUSIONS: On the basis of our data and those from literature, we suggest that platelets may be affected very little or severely damaged during cardiopulmonary bypass for cardiac surgery, probably depending on some aspects of the technical procedure which remain to be identified. Aprotinin infusion significantly protects platelets in the latter condition, while its role is obviously slight in the former.

Aprotinin↗