Complete nucleotide sequence of the 16S rRNA gene of Mycobacterium bovis BCG

The complete nucleotide sequence of the 16S rRNA gene of Mycobacterium bovis BCG was determined. Its coding region was estimated to be 1,536 base pairs long. The nucleotide sequence of the gene in M. bovis BCG has homologies of 75 and 89% with those of Escherichia coli and Streptomyces lividans, respectively.

Molecular cloning and characterization of an rRNA operon in Streptomyces lividans TK21

The number of rRNA genes in Streptomyces lividans was examined by Southern hybridization. Randomly labeled 23 and 16S rRNAs were hybridized with BamHI, BglII, PstI, SalI, or XhoI digests of S. lividans TK21 DNA. BamHi, BglII, SalI and XhoI digests yielded six radioactive bands each for the 23 and 16S rRNAs, whereas PstI digests gave one band for the 23S rRNA and one high-intensity band and six low-density bands for the 16S rRNA. The 7.4-kilobase-pair BamHI fragment containing one of the rRNA gene clusters was cloned into plasmid pBR322. The hybrid plasmid, pSLTK1, was characterized by physical mapping, Southern hybridization, and electron microscopic analysis of the R loops formed between pSLTK1 and the 23 and 16S rRNAs. There were at least six rRNA genes in S. lividans TK21. The 16 and 23S rRNA genes were estimated to be about 1.40 and 3.17 kilobase pairs, respectively. The genes for the rRNAs were aligned in the sequence 16S-23S-5S. tRNA genes were not found in the spacer region or in the context of the rRNA genes. The G + C content of the spacer region was calculated to be approximately 58%, in contrast to 73% for the chromosome as a whole.

Chlorpromazine alters bone metabolism of rats in vivo

The acute effect of chlorpromazine (CPZ) on metabolic changes in rats was investigated. CPZ was found to markedly suppress 45Ca incorporation into the calvarium and ileum in vitro. According to the serum and/or urinary levels of certain markers for bone metabolism, the increases of Ca and P in the serum and Ca, P, and gamma-carboxyglutamate (Gla) in the urine were observed in rats given 10 mg CPZ/kg of their body weight, whereas the amount of alkaline phosphatase (ALP) activity, ionized Ca, calcitonin, 25-hydroxyvitamin D3 (25(OH)D3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) as clearly or slightly reduced, suggesting the inhibitory effect of their bone formation. This was well supported since only bone type ALP was detected in the urine and loss of the vertebral bone density from rats given daily CPZ administration for a week. Moreover, in this case, there is little if any difference in the levels of mid-molecule parathyroid hormone (mid-PTH), osteocalcin, and urinary cAMP for the nontreated and CPZ-treated animals, resulting in the fact that CPZ may mainly inhibit the hydroxylase for active vitamin D3.

Hypercalcemia of cancer in the digestive tract

We made a retrospective review of the patients with cancer of the digestive organs who died between January 1, 1975 and December 31, 1985, at Shinshu University Hospital. Of 183 patients with such cancers 15 (8.2%) had hypercalcemia. Hypercalcemia was defined as serum calcium level greater than 11.0 mg/dl on at least two determinations. The incidence of hypercalcemia by site was 5 of 74 (6.8%) liver, 1 of 16 (6.3%) biliary tract, 4 of 33 (12.1%) pancreas, 3 of 15 (20.0%) esophagus, 0 of 37 stomach, 0 of 2 duodenum, 2 of 5 colon, and 0 of 1 rectum carcinomas. There was no sexual or age predisposition to hypercalcemia. Bone scans and/or x-ray results were positive in three of eight, negative in five of eight, and were not evaluated in the remaining seven patients. Of five patients tested, four had low to normal serum parathyroid hormone (PTH) levels, and one had a serum PTH level high by C-terminal assay but normal by N-terminal assay. Serum chloride levels at the late stage of hypercalcemia were less than 102 mEq/L in all patients. Therefore, hyperproduction of PTH was unlikely to be a causative factor for hypercalcemia. Indomethacin was given to four patients with hypercalcemia with no effect on serum calcium levels in any cases. Survival from the diagnosis of hypercalcemia ranged from 2 to 96 days (mean 33 days). We conclude that hypercalcemia is a complication not infrequent at the late stages of cancers of the digestive organs, with the exception of gastric cancer, and a portent of a poor prognosis.

Organization of rRNA genes in Mycobacterium bovis BCG

The number of rRNA genes in Mycobacterium bovis BCG was examined by Southern hybridization of end-labeled 5S, 16S, and 23S rRNAs with BamHI, PstI, and SalI digests of M. bovis BCG DNA. Each RNA probe gave only one radioactive band with three kinds of DNA digest. These results suggest that M. bovis BCG chromosomes may carry only a minimum set of rRNA genes. Hybridization of randomly labeled rRNAs with BamHI, PstI, SalI, BglII, and PvuII digests of DNA from the same organism supported these conclusions. The 6.4-kilobase-pair SalI fragment containing the entire structural genes for both 16S and 23S rRNAs was cloned into pBR322. The cloned fragment was characterized by restriction endonuclease mapping, DNA-RNA hybridization analysis, and the R-loop technique. The results indicated that the fragments contained rRNA genes in the following order: 16S, 23S, and 5S rRNA genes. No tRNA gene was detected in the spacer region between the 16S and 23S rRNA genes, but one was found downstream of the 23S rRNA and 5S rRNA genes.

A possible mechanism of induction and translocation into blood stream of rat alkaline phosphatase activity by bile duct ligation

We investigated the effects of bile duct ligation on alkaline phosphatase (ALP) activities in liver, calvarium, duodenum, and ileum in rats and its possible mechanism of action. ALP isozyme activities in the ligated rats were significantly elevated in the liver and duodenum, while those in the ileum and calvarium were markedly decreased. The ALP isozyme activity elevated by the ligation was obviously suppressed by prior administration of indomethacin, an inhibitor of prostaglandin synthesis. Moreover, phorbol ester also elevated the ALP activity as well as the phosphatase level in the ligated rat. However, other drugs, such as an inhibitor of protein kinase C and calmodulin, showed different effects: calmodulin stimulated an 11.0-, 1.3-, or 1.5-fold increase in ALP activity in the ileum, duodenum, or calvarium, respectively; whereas the hepatic enzyme activity was not affected. The induction by calmodulin was markedly different from that by the ligation. Moreover, imipramine, an inhibitor of protein kinase C, had little effect. These results suggest that prostaglandin is a possible ALP inducer in ligated rats, probably working by elevating the cAMP level. On the other hand, the ligation induced simultaneously de novo synthesis of the membranous and soluble ALP isozymes; and the release rate of the soluble enzyme was greater than that of the membranous isozymes, indicating that the soluble enzyme might be a main source of the induced serum ALP. Lectin affinity chromatography indicated that the soluble enzyme or induced serum enzyme may contain more fucose than that of the membranous one, suggesting that the sugar moiety in the ALP molecule may relate to the clearance of ALP from or its release into the circulation.

Ontogenic and phylogenic studies of intestinal, hepatic, and placental alkaline phosphatases. Evidence that intestinal alkaline phosphatase is a late evolutionary development

We have studied the intrauterine development of guinea pig and rat organ phosphatases using biochemical, immunologic, and histologic techniques. In all organs tested the features of the adult phosphatase activity were achieved during the second or third gestational phases. In the rat, the tissue-unspecific phosphatase activity was found by immunoprecipitation with antiserum to rat liver phosphatase in all gestational phases in liver and placenta. The high liver activity in the first phase of gestation corresponded to hematopoietic cells. Hepatocyte phosphatase did not appear until the second gestational phase. The tissue-unspecific phosphatase activity was found in the first and second gestational phase in surface intestinal epithelial cells, even after crypt formation occurred. Once phosphatase appeared in enterocytes on villi, only the intestinal-type enzyme was detected. Alkaline phosphatase was measured in the liver and intestine from animals in various phyla. In fish and reptiles, the intestinal activity had the enzymatic characteristics of the tissue-unspecific enzyme. The appearance of intestinal alkaline phosphatase with unique properties and high specific activity is a characteristic of mammals.

Intramuscular and surface electromyogram changes during muscle fatigue

Twelve male subjects were tested to determine the effects of motor unit (MU) recruitment and firing frequency on the surface electromyogram (EMG) frequency power spectra during sustained maximal voluntary contraction (MVC) and 50% MVC of the biceps brachii muscle. Both the intramuscular MU spikes and surface EMG were recorded simultaneously and analyzed by means of a computer-aided intramuscular spike amplitude-frequency histogram and frequency power spectral analysis, respectively. Results indicated that both mean power frequency (MPF) and amplitude (rmsEMG) of the surface EMG fell significantly (P less than 0.001) together with a progressive reduction in MU spike amplitude and firing frequency during sustained MVC. During 50% MVC there was a significant decline in MPF (P less than 0.001), but this decline was accompanied by a significant increase in rmsEMG (P less than 0.001) and a progressive MU recruitment as evidenced by an increased number of MUs with relatively large spike amplitude. Our data suggest that the surface EMG amplitude could better represent the underlying MU activity during muscle fatigue and the frequency powers spectral shift may or may not reflect changes in MU recruitment and rate-coding patterns.

Study of chronic alcoholic pancreatitis by means of serial pancreozymin-secretin tests

Fourteen patients with suspected chronic alcoholic pancreatitis (CAP) and 21 patients who had been shown to have the disease were followed up by the pancreozymin-secretin test in order to clarify the serial changes in exocrine pancreatic function in alcoholic pancreatitis. The initial and final test data for secretory volume, maximal bicarbonate concentration, bicarbonate output (BO), and amylase output (AmO) of exocrine secretion were compared in these two groups. Patients with suspected CAP showed a significant serial decrease only in AmO; definite CAP developed in 3 of them during the follow-up period. In definite CAP, a significantly progressive decrease in BO as well as AMO was observed. It is suggested that in the earlier stage of CAP, AMO is initially affected, whereas decreased secretion of both bicarbonate and enzyme becomes apparent in the later stage.

DNA content of hepatocytes in various stages of liver cirrhosis

In order to search for some parameters that would make it possible to predict a potentially high risk of evolution from liver cirrhosis to hepatocellular carcinoma (HCC), the DNA content of hepatocytes in patients with liver cirrhosis with or without development to HCC was investigated by means of microspectrophotometry in Feulgen-stained specimens. In patients without development of HCC in more than 5 years of follow-up, 90% or more of tested hepatocytes were diploid, whereas in patients with liver cirrhosis who developed HCC within 3 years the frequency histogram of nuclear DNA content was widely spread from diploid to hyperpolyploid with a small peak of triploid. Furthermore, in the latter group of patients, many of the binucleate cells had different DNA contents in each paired nucleus. In non-cancerous portions of HCC, the ploidy histogram of nuclear DNA content was widely spread from diploid to polyploid with different DNA contents of each paired nucleus in binucleate cells, without the small peak of triploid. These results suggest that the deranged cell kinetics of hepatocytes in cirrhosis may be considered to be a state of potentially high risk for the evolution of HCC, and that a patient with liver cirrhosis with such an abnormal hepatocyte DNA content should be followed up carefully for the early diagnosis of HCC.

Alteration of ribosomes and RNA polymerase in drug-resistant clinical isolates of Mycobacterium tuberculosis

The biochemical mechanism of resistance to kanamycin, viomycin, and rifampin in five clinical isolates of Mycobacterium tuberculosis was studied. Resistance to viomycin and kanamycin was attributed to altered ribosomes, whereas resistance to rifampin was attributed to an alteration of RNA polymerase. Ribosomal resistance was, however, not the only way of expressing resistance to viomycin and kanamycin.