A clinical study of Japanese patients with ulcer induced by low-dose aspirin and other non-steroidal anti-inflammatory drugs.

BACKGROUND: The incidence and severity of non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastro-duodenal ulcer have not been extensively studied in Japan. AIM: We performed a prospective study to clarify NSAIDs-induced gastro-duodenal injury, focusing especially on low-dose aspirin (L-A). METHODS: Two hundred and thirty-eight patients with bleeding peptic ulcers admitted to our hospital. History of taking NSAIDs and anti-ulcer drugs was obtained from all patients who underwent endoscopic examinations. The lesion scores of patients taking L-A were classified numerically from zero (no lesion) to five (ulcer). RESULTS: The NSAIDs were associated with 28.2% of hemorrhagic ulcers. The rates of patients using L-A, loxoprofen, diclofenac, and combination of two of these drugs were 27, 16, 10 and 9%, respectively. Co-administered anti-ulcer drugs were cytoprotective anti-ulcer drugs (27%), H2 receptor antagonists (16%), PPI (4%), and none (53%). In patients taking L-A, H2 receptor antagonists were used most frequently. The HP was positive in 63% of L-A-induced ulcer cases and in 69% of NSAIDs other than low-dose aspirin-induced ulcer cases. The lesion scores of patients taking L-A with H2 receptor antagonists or PPI were significantly lower than those of patients who were taking only L-A (P < 0.05). CONCLUSIONS: Approximately one-third of hospitalized patients with NSAIDs-induced hemorrhagic ulcer showed an association with L-A. Prospective randomized controlled trials including H2 receptor antagonists are required to establish preventive efforts aimed at L-A-induced gastro-duodenal injury.

Possible role of aldosterone and T(3) in development of amiloride-blockable SCC across frog skin in vivo.

There are inconsistencies between the in vitro and in vivo effects of thyroid hormone and aldosterone (Aldo) on the development of an amiloride-blockable short-circuit current (SCC) across bullfrog skin [Takada, M., H. Yai, and K. Takayama-Arita. Am. J. Physiol. 268 (Cell Physiol. 37): C218-C226, 1995]. To address this issue, tadpoles were raised in Aldo + T(3). An amiloride-blockable SCC developed across the skin before forelimbs appeared. Noise analysis of the characteristics (single-channel current, blocking and unblocking rate coefficients, and apparent dissociation constant) of this amiloride-blockable Na(+) channel showed that it really was of the adult type. A similar SCC developed at stage XIX in the skin of tadpoles raised with Aldo alone. These results strongly support our hypothesis that the crucial hormone in the development of this SCC is Aldo but that a suppression mechanism attenuates its effect on SCC development until it is removed by the increase in the serum concentration of thyroid hormone (which starts at stages XVIII-XIX in vivo).

Computational studies on the decarboxylation of 2-(1-carboxy-1-hydroxyethyl)-3,4-dimethylthiazolium dipolar ion, an analog of the complex of pyruvic acid and coenzyme of the pyruvate decarboxylase.

We have obtained the optimized geometrical structure of 2-(1-carboxy-1-hydroxyethyl)-3,4-dimethylthiazolium dipolar ion and investigated its geometric and electric changes during decarboxylation process by the MNDO-PM3 method, a molecular orbital method. The salient features of the optimized structure are that the dihedral angle of C4-C1-C2-S3 is 5.4 degrees and the distance between thiazolium S3 and carboxyl O6 is about 1.8 A (the bond order between S3 and O6 is about 0.4). The lowest energy decarboxylation profile is the following process. First the dihedral angle of C4-C1-C2-S3 becomes about 90 degrees, then the distance between C1-C2 increases while the dihedral angle holds about 90 degrees, and finally the C1-C2 bond disappears. The most remarkable change caused by the 90 degrees rotation is the disappearance of the S3-O6 bond, and this disappearance causes electric changes that prompt the decarboxylation.