Isoproterenol-induced myocardial injury resulting in altered S100A4 and S100A11 protein expression in the rat.

S-100 proteins (S100) are characterized by calcium-binding ability with two structural EF hands. Several S100 are expressed in cardiomyocytes and thought to play a crucial role in calcium signaling. To examine whether the expression of S100 is a response to detectable myocardial damage or regeneration, we investigated, immunohistochemically, the expression of S100A4 and S100A11 in the isoproterenol (ISP)-treated rat heart. Definite expression of S100A4 and S100A11 was demonstrated in normal cardiomyocytes, and their staining patterns were enhanced in the ISP-treated rat heart, suggesting the possible involvement of S1-A4 and S100A11 in ISP-induced myocardial damage.

Comparative studies of suidatrestin, a specific inhibitor of trehalases.

Suidatrestin, isolated from a Streptomyces strain, was characterized as a new trehalase inhibitor. Its inhibitory potential was 7 to 50-fold higher than that of validamycin when tested against insect, fungal and mammalian trehalases. The kinetic properties of suidatrestin were studied in vitro with trehalases from flight muscle mitochondria of the fly, Protophormia terraenovae, from larval midgut of the moth, Spodoptera littoralis, and from porcine kidney, as well as with maltase from yeast. Suidatrestin was inactive on maltase but inhibited all trehalases with IC50 values of 0.08-0.1 microM; Ki values ranged from 0.02 to 0.05 microM. The very low Ki/K(m) ratios (3.9 x 10(-6) -4.9 x 10(-6)) indicated excellent in vitro inhibitory action of suidatrestin. When injected into larvae of S. littoralis, suidatrestin required high and repetitive doses which lead to reversible inhibition of larval growth only. Consecutive omission of the inhibitor even stimulated weight increase above that of controls. Significant mortality was achieved at a rather high dose only. Injection of a growth-inhibiting dose of suidatrestin did not change hemolymph osmolality as a measure of sugar concentration. The discrepancy between in vitro and in vivo potency of suidatrestin may be understood once its chemical structure is fully known.

Gene expression of hypothalamic growth hormone (GH)-releasing hormone and somatostatin does not correlate with pulsatile secretion of GH in the adult mouse.

The secretion of growth hormone (GH) shows a pulsatile pattern in many mammalian species, and depends on the interaction of two hypothalamic hormones, GH-releasing hormone (GHRH) and somatostatin (SRIH). A surge of GHRH secretion into the hypophysial portal blood induces peak secretion of GH from the anterior pituitary. To study whether the rhythmic and reciprocal oscillation in secretion of GHRH and SRIH are associated with changes in synthesis of these peptides, we examined the expression of hypothalamic GHRH and SRIH mRNA by Northern blotting during trough and peak phases of GH secretion in male mice. Hypothalamic GHRH and SRIH mRNA levels did not differ between trough and peak phases of GH secretion. This result suggests that changes in GHRH and SRIH secretion have little association with changes in the synthesis of these peptides at the hypothalamus in the male mouse.

[A case of colon cancer associated with schistosomiasis japonica].

A case of colon cancer associated with schistosomiasis japonica is reported. A 60-year-old man was admitted with the complaint of melena. Barium enema study revealed a colon tumor (type 1') 11 cm from the anal ring. Sigmoidectomy was performed, and no lymph node metastasis was observed. Histologically, the tumor was diagnosed as well-differentiated adenocarcinoma, and also many schistosoma ova were found not only in the lesion of the carcinoma, but also in the tissue surrounding the carcinoma. In the latter lesion, ova were observed beneath muscularis mucosae. The distributions of the ova in the anal side of the tumor were more dominant than those in oral side. We review the direct correlation between gastrointestinal tract cancer and the schistosomiasis japonica in other reports.

Long-term clinical effect of calcium inhibitors in hypertrophic cardiomyopathy compared to the effect of beta-blocking agents. A preliminary report with special reference to the beneficial effect of nifedipine on angina pectoris.

Long-term clinical effects of beta-blockers (propranolol in most cases) and calcium inhibitors (nifedipine in most cases) were studied in 16 patients with hypertrophic cardiomyopathy. On overall subjective symptoms, beta-blockers were effective in 50% of symptomatic patients, while calcium inhibitors were effective in only 33%. On angina pectoris, however, calcium inhibitors were superior to beta-blockers in our patients. Blood pressure decreased with each drug, and the decrease was significant with nifedipine. Otherwise there was no change in physical findings with either drug. Long-term (more than 6 months) use of beta-blockers resulted in an increase in cardiothoracic ratio on chest X-ray, a decrease in left ventricular ejection fraction on echocardiogram and more pronounced ST-T change on electrocardiogram. Prolonged use of nifedipine resulted in a slight decrease in cardiothoracic ratio, but no systematic change on echocardiogram and on electrocardiogram.