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A Spina

Publications and source records attributed to A Spina.

At least 37 records · Page 2Linked to original sources

A stimulating effect of guanyl nucleotides on the rat-liver soluble cyclic GMP high-affinity phosphodiesterase activity.

The high affinity (low Km) cyclic GMP phosphodiesterase (PDE) is activated by GTP, while the cyclic AMP PDE is not. GTP and its hydrolysis-resistant analogue, guanylylimidodiphosphate (GppNHp), display a half-maximal stimulating effect at almost the same concentration (5 X 10(-6) M). The GTP stimulating effect is not observed when the socalled cyclic GMP low affinity (high Km) PDE is operative. GTP cooperates with the increase of the substrate concentration on removing the IBMX inhibitory effect. The isolation through a classical chromatographic procedure on a DEAE-cellulose column, of a PDE fraction specific for cyclic GMP, results in the loss of the GTP stimulating effect.

1-Methyl-3-isobutylxanthine↗

Adriamycin causes hyperlipemia as a consequence of nephrotoxicity.

Adriamycin induced hyperlipemia: its features and mechanism(s) in rats were investigated. Massive hyperlipemia occurred 14-21 days after a single dose of adriamycin (7.5 mg/kg i.v.). All lipoprotein fractions were affected. Mild but significant changes in tissues were observed (liver and intestine triglycerides and kidney phospholipids were reduced). Lipid synthesis and secretion was decreased, as shown by the Triton WR1339 test 7 days after treatment, but subsequently returned to normal. Mitochondrial oxidation of long-chain fatty acids was markedly reduced in kidney, and a slight reduction was also observed in heart. Lipoprotein lipase activity was reduced in adipose tissue. These results suggest that adriamycin hyperlipemia is due to reduced lipid storage and utilization. Carnitine did not counteract hyperlipemia and proteinuria after adriamycin. Analogies to hyperlipemia following puromycin aminonucleoside-induced nephrotoxicity are discussed.

Animals↗

Clinical features and hormonal characteristics in a case of ovarian arrhenoblastoma.

We report a case of a 34-year-old woman affected with ovarian arrhenoblastoma characterized by very high testosterone (T) levels (34.0-60.0 ng/ml; n.v.0.2-0.9) and suppressed gonadotropin levels. The physical examination revealed: severe hirsutism, acne, amenorrhea and other virilization signs. Basal hormonal evaluation also showed a markedly elevated 17-hydroxyprogesterone (17-OHP) and a mild delta 4 Androstenedione (A) and dehydroepiandrosterone sulfate (DHEAs) increase. ACTH test induced only slight changes in androgen secretion. By contrast, dexamethasone test greatly decreased A and DHEAs whereas T levels were only partially suppressed. Moreover, hCG test was clearly stimulatory for T and A. Suppressed gonadotropin levels did not respond to LHRH stimulation. The removal of the neoplasia was followed by normalization of T levels and increase of serum gonadotropins with subsequent restoration of a normal responsiveness to LHRH and resumption of an ovulatory menstrual cycle. This observation suggests that the high T levels played a primary role in the pathogenesis of the gonadotropin suppression and anovulation. Recovery of acne was complete whereas hirsutism score was reduced but still elevated after one year. This may be due to postoperative A and DHEAs levels slightly above the normal range, indicating the presence of adrenal hyperandrogenism.

17-alpha-Hydroxyprogesterone↗