DNA dependent RNA polymerase from Ehrlich ascites tumor cells. V. Characterization of a factor repressing RNA polymerase II as a ribonucleoprotein

Previously we reported the isolation of a factor, named the R-protein, which strongly repressed RNA polymerase II [EC 2.7.7.6] of Ehrlich ascites tumor cells. In the present work this factor was found to contain much RNA (ratio of RNA to protein, 2.3 to 1). The RNA was G:C rich, with a very high content of guanylic acid (about 38%). On equilibrium density gradient centrifugation in Cs2SO4 solution, the RNA became distributed above free RNA, but after digestion of the R-protein with pronase the RNA cosedimented with free RNA. Thus the R-protein is a complex of RNA and protein.

[Calcification in gliomas: first report with special reference to roentgenological calcification (author's transl)]

The mechanism and the clinical significance of calcium deposits in glioma have been still obscure. Excluding pinealomas, 221 histologically proven intracranial gliomas were studied. The presence of roentgenological calcification in 27 of the authers' series represented an incidence of 12 percent. The incidence of roentgenological calcification in various types of glioma were as follows: astrocytoma grades 1 & 2-15%, astrocytoma grades 3 & 4-7%, medulloblastoma-5%, ependymoma-17%, oligodendrogioma-60%, and choroid plexus papilloma-25%. There was no characteristic relationship between the incidence of calcification and the age distribution. One exception was noted that in astrocytoma grades 1 & 2 the incidence of roentgenological calcification tended to be higher in younger patients than in older patients. The percentage of calcified tumors in both sexes was the same. In astrocytoma and ependymoma the incidence of roentgenological calcification was far greater in the supratentorial tumor than in the infratentorial tumor. According to their roentgenological appearance, calcified tumors were separated into four groups, but any specific appearance could not be claimed for any particular type of glial tumors. Only in astrocytoma both the duration of symptoms and the postoperative survival time of the calcified cases were longer than those of the uncalcified. But in other types of glioma there were no significant differences in the postoperative survival time between the calcified cases and the uncalcified ones. In 5 cases of astrocytomas the calcium deposits did not exist on preoperative radiographs, which were found postoperatively after chemotherapy and/or radiotherapy. In conclusion, it is not the histological type but the duration of the clinical course that plays more important role in calcification of gliomas.

Influence of the proximal small intestine on the gastric hypersecretion in pylorus-ligated rats

The mechanism of the gastric secretory inhibition caused by the simultaneous ligation of the upper and lower duodenum or the jejunum in pylorus-ligated rats was studied. The data obtained from the experiments on surgical manipulation of the small intestine indicated that the absorption of certain substances appeared to be important in maintaining gastric secretion of pylorus-ligated rats. The participation of biliary secretion was negligible, while the ligation procedure per se, which results in the accumulation of duodenal contents, might be partly involved in the mechanism of acid secretion. Pharmacological techniques suggested that the inhibition appeared to be independent of cholinergic nervous reflex and hormonal influence, which is assumed to be released by intestinal acidification.

Inhibitory effect of L-glutamine on the aspirin-induced gastric lesions in the rat

The effects of an amino acid, L-glutamine, on aspirin-induced gastric lesions and gastric secretion were studied in either intact or pylorus-ligated rats. L-Glutamine had a pronounced inhibitory effect on gastric lesions induced by aspirin administered by oral, intraperitoneal, or intraduodenal routes to intact or pylorus-ligated rats. By the oral route the inhibition was dose-related. However, L-glutamine given either intraduodenally or intraperitoneally did not show any appreciable effects on gastric lesions induced by orally administered aspirin in pylorus-ligated rats. One mechanism of L-glutamine protection was inhibition of a back diffusion of gastric acid caused by aspirin and this was demonstrated in pylorus-ligated rats. The reduction in H+ and increase in Na+ concentrations in the lumen caused by aspirin was returned to normal by increasing doses of L-glutamine. In addition, L-glutamine was considered to inhibit the back diffusion of acid caused by pylorus ligation per se, because the amino-acid produced an increment of H+ and reduction of Na+ and K+ in comparison with the control group. The role of pepsin on L-glutamine protection was negligible.