Revised nucleotide sequence of the sporulation gene spoVE from Bacillus subtilis.
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Bacillus subtilis↗
Biomedical subjects
M Okamoto
Publications and source records attributed to M Okamoto.
Molecular cloning and expression of cDNAS encoding rat aldosterone synthase: variants of cytochrome P-450(11 beta).
Two distinct forms of cDNA encoding rat aldosterone synthase were cloned from an adrenal capsular tissue cDNA library. The deduced amino acid sequences showed that one of the enzymes (P-450(11 beta),aldo-1) had a long extension peptide composed of 34 amino acid residues while the other (P-450(11 beta),aldo-2) had an extension peptide identical to that of rat P-450(11 beta). Glu at the 320th position of P-450(11 beta),aldo-1 was replaced with Lys in P-450(11 beta),aldo-2. The amino acid sequence of the aldosterone synthase was highly homologous (81%) to rat P-450(11 beta). Constructed expression vector containing the cDNA for extension peptide of P-450(11 beta) and the mature protein of P-450(11 beta),aldo-1 was transfected into COS-7 cells. The cells converted 11-deoxycorticosterone into corticosterone, 18-hydroxycorticosterone, and aldosterone.
Amino Acid Sequence↗
Induction of DNA damage by dimethylarsine, a metabolite of inorganic arsenics, is for the major part likely due to its peroxyl radical.
To reveal the mechanisms of previously reported lung-specific DNA strand scissions in murine after oral administration of dimethylarsinic acid (DMAA), a main metabolite of inorganic arsenics in mammals, the ultimate substance causing DNA lesion was investigated using dimethylarsine which was a further metabolite of DMAA. The alkaline elution assay using 3H-labeled DNA showed that a major portion of the strand breaks was not suppressed by SOD and catalase, suggesting an ultimate substance other than active oxygen participated in the DNA damage. By ESR analysis, a radical estimated to be (CH3)2AsOO. was detected as a reaction product of dimethylarsine and molecular oxygen. This peroxyl radical, rather than active oxygen, was assumed to play a major role in DNA damage.
Arsenic Poisoning↗
Nucleotide sequences of the gene/cDNA coding for anti-murine erythrocyte autoantibody produced by a hybridoma from NZB mouse.
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Amino Acid Sequence↗
Molecular nature of chromosome 5q loss in colorectal tumors and desmoids from patients with familial adenomatous polyposis.
Familial adenomatous polyposis (FAP), which includes familial polyposis coli (FPC) and the Gardner syndrome (GS), is a genetically determined premalignant disease of the colon inherited by a locus (APC) mapping within 5q15-q22. To elucidate the role of 5q loss in FAP tumorigenesis, we analysed 51 colorectal tumors and seven desmoids from 19 cases of FPC and five GS patients, as well as 15 sporadic colon cancers. RFLP analysis revealed a high incidence of allelic deletion in hereditary colon cancers as well as in sporadic colon cancers with a peak at the APC locus. APC loss resulted primarily from interstitial deletion or mitotic recombination. Combined tumor and pedigree analysis in a GS family revealed loss of normal 5q alleles in three tumors, including a desmoid tumor, which suggests the involvement of hemizygosity or homozygosity of the defective APC gene in colon carcinogenesis and, possibly, in extracolonic neoplasms associated with FAP.
Adenomatous Polyposis Coli↗
Growth of a Japanese isolate of Taenia crassiceps in intermediate and definitive hosts.
Higher infection rates were observed in gerbils and voles than in ICR mice after oral inoculation with eggs of a Japanese isolate of Taenia crassiceps. Asexual reproduction of T. crassiceps cysticerci was observed in all gerbils and voles infected i.p. with the cysticerci. However, ICR mice and Wistar rats were not suitable for the asexual proliferation of T. crassiceps. The hooks of cysticerci from mice were smaller than those from gerbils. In experimentally infected puppies, parasite development was noted as follows: strobilation and initial differentiation of the genital primordia on day 7 postinoculation (p.i.), appearance of the testes on day 9, observation of the ovaries on day 10, and development of the lateral branches of the uterus on day 15. The prepatent period was 27-31 days. After day 15 p.i., most of the worms were recovered from the middle third of the small intestine. The number of proglottids shed per day by each strobila was about 1. The number of eggs contained in a gravid segment was about 13,000.
Animals↗
The interactions of ouabain with post-tetanic and facilitatory drug potentiations at cat soleus neuromuscular junctions in vivo.
Cat soleus motor nerve terminals, after high frequency conditioning, generate a post-tetanic repetition (PTR) which leads to a post-tetanic (PTP) of the muscle response. This property enables quantitative assessment of enhancement or depression of this nerve terminal excitability in vivo. The present study focuses on ionic mechanisms underlying the PTRs produced in this neuromuscular system either by high frequency stimulation or edrophonium. Ouabain was used as a specific probe for inhibition of Na(+)-K+ ATPase and its known consequences on Na+ and Ca2+ translocation. Ouabain pretreatment doubled the duration over which single stimuli, following either high frequency or edrophonium conditioning produced PTR. Ouabain in the doses used had no effect per se but as a function of dose augmented the frequency dependent responses. This pointed to Na+ loading of nerve terminals via high frequency stimulation plus ouabain inhibition of Na(+)-K+ ATPase. Ouabain potentiation of PTR responses evidently depends on exchange of intra-terminal sodium for external calcium. Thus, calcium entry blockers, Mn2+, and Co2+ suppressed or abolished the potentiations both before and after ouabain. Diphenylhydantoin, a Na+ and Ca2+ blocker, acted similarly. The effects of stimulation frequency, ouabain and the sequence of events leading to PTR in the soleus neuromuscular system appeared in general no different from those derived from the many in vitro microphysiologic studies of this phenomenon. Thus, EPPs were augmented and prolonged. It was concluded that intracellular Ca2+ is critical for regulating the stability of systems in which repetitive firing is both a normal and abnormal function.
Animals↗
Immunocytochemical studies on the localization of pancreatic-type phospholipase A2 in rat stomach and pancreas, with special reference to the stomach cells.
Using a specific polyclonal antibody raised against rat pancreatic phospholipase A2 (PLA2), we investigated the localization of the enzyme in the rat pancreas and stomach by light and electron microscopy. In the pancreas, the enzyme was localized in the acinar cells, whereas the pancreatic islets showed no immunoreaction. In the stomach, the PLA2 reactive with the anti-pancreatic PLA2 antibody was distributed exclusively in the gastric glands, but not in the gastric pits or the pyloric glands. On the section of the stomach subjected to immuno- and PAS-staining, immunopositive cells were not the PAS-positive cells located in the gastric pit and the neck region of the gastric gland. Immunopositive cells were present from the neck to the bottom of the gastric gland. Immunoelectron microscopic observation revealed that the immunogold-labeled cell had a highly-developed rough endoplasmic reticulum in the basal cytoplasm and characteristic zymogen granules in the apical cytoplasm. Taking into account the cell position in the gastric gland, the immunopositive cell could therefore be identified as a chief cell. Since no double stainability with PLA2 and PAS was observed in the same cell, it is suggested that PLA2 could be used cytochemically as a marker enzyme of the chief cell in the gastric gland at the light-microscopic level. From the immunoelectron microscopic findings, we believe that the PLA2 in the stomach is released into the lumen of the stomach by exocytosis and could function as a digestive enzyme in the alimentary tract, like the PLA2 secreted from the pancreas. Other possible roles of the PLA2 in the stomach are discussed.
Animals↗
Network study of integrated biochemical switching system. I: Connection of basic elements.
As a first step to network study, a series of integrated biochemical switching systems (prototype of artificial neuronic device) was assumed based on Rosen's work and on the results of our previous studies. The effects of an excitatory stimulus on the switching properties of the proposed system were examined using computer simulations. The results can be summarized as follows: (i) the number of excited elements in sequentially connected systems is proportionally related to the value of the excitatory stimulus; (ii) when the introduction of the excitatory stimulus is too late, it can no longer be transmitted to any elements; (iii) the excitatory stimulus (signal) is amplified to a certain limit and is attenuated during propagation; (iv) by assuming several excitatory stimuli and varying their frequencies, the so-called long-term potentiation phenomenon can be observed; (v) supposing reversible interactions between two elements, a continuous switching pattern of the output is observed.
Animals↗
An analysis of anticonvulsant actions of GABA agonists (progabide and baclofen) in the kindling model of epilepsy.
The anticonvulsant action of progabide, an agonist of gamma-aminobutyric acid (GABA)A and GABAB receptors, was investigated in the kindling model of epilepsy in rats. Progabide shortened afterdischarge durations and attenuated the severity of the accompanying convulsive responses in previously kindled rats from the amygdala (AM), frontal cortex (FC), ventral and dorsal hippocampus (HIPP), in a dose-dependent manner. Although progabide was less effective in the dorsal HIPP kindled seizures, the efficacy was potent in AM, FC and ventral HIPP kindled seizures. On the other hand, the anticonvulsant action of baclofen, a selective agonist of GABAB receptors, was relatively weak in terms of the measurement of the afterdischarge duration of AM and HIPP kindled seizures even at toxic doses, compared with progabide. In addition, the anticonvulsant effects of progabide were partially reversed by treatment with the antagonist of benzodiazepine receptors, Ro 15-1788, whereas Ro 15-1788 administration alone did not alter AM kindled seizures. We concluded that the action of progabide may be mediated via the GABA/benzodiazepine receptor complex. These results support the hypothesis that a failure of GABAA-mediated inhibition is one of the bases of induction and generalization of seizures.
Animals↗
Assessment of supra-valvular abnormal signal with color Doppler flow mapping in patients with aortic regurgitation.
A supra-aortic abnormal flow signal (proximal acceleration) was studied in 62 patients with aortic regurgitation with the use of color Doppler flow mapping. The proximal acceleration signal was detected in 28 of the 62 patients and was shaped like a V or a teardrop. In the 29 patients who underwent aortography, a proximal acceleration signal was observed in all 18 patients with severe and moderate regurgitation and in only one of the 11 patients with mild regurgitation. The sensitivity for the diagnosis of severe regurgitation from the existence of a proximal acceleration signal was 100%, specificity 50%, and predictive accuracy 47%. A close correlation between the area of the proximal acceleration signal and the width of the aortic regurgitant jet signal was observed (r = 0.81). An acceleration area of 45 mm2 or more was observed in eight of the nine patients with severe regurgitation, in four of the nine patients with moderate regurgitation, and in none of the patients with mild regurgitation. Sensitivity for the diagnosis of severe regurgitation from an area of proximal acceleration of more than 45 mm2 was 89%, specificity 80%, and accuracy 67%. These results suggest that evaluation of the area of the supra-aortic abnormal signal may be a useful auxiliary aid in estimating the severity of aortic regurgitation.
Adolescent↗
Amplification and high-level expression of a cDNA for human granulocyte-macrophage colony-stimulating factor in human lymphoblastoid Namalwa cells.
We have achieved high-level expression of human granulocyte-macrophage colony-stimulating factor (GM-CSF) in human lymphoblastoid Namalwa cells by introducing and subsequently amplifying an expression vector encoding human GM-CSF and mouse dihydrofolate reductase (DHFR). Transformants expressing elevated levels of both GM-CSF and DHFR were selected by a step-wise increase in the concentration of methotrexate (MTX). Several cell lines resistant in 800 nM MTX have been established that express GM-CSF at a rate of 10-20 micrograms/10(6) cells/day. The amplified genes are integrated and stably maintained in the chromosomes of these cell lines. Analysis of the GM-CSF produced in the amplified Namalwa cells revealed that the molecular-size distribution due to varied degrees of glycosylation was similar to that observed in the naturally-occurring molecules.
Cloning, Molecular↗
Enzymatic activities of P-450(11 beta)s expressed by two cDNAs in COS-7 cells.
Expression plasmids were constructed using two cDNA clones of P-450(11 beta), pcP-450-(11 beta)-2, and pcP-450(11 beta)-3 (Morohashi et al. (1987) J. Biochem. 102, 559-568 and Kirita et al. (1988) J. Biochem. 104, 683-686), and introduced into COS-7 cells by electroporation. The expression of P-450(11 beta) proteins and their localization in the mitochondria were demonstrated by immunoblotting, immunofluorescence microscopy, and immunoelectron microscopy. The enzymatic activities of the expressed P-450(11 beta)s were determined using deoxycorticosterone (DOC), deoxycortisol, and corticosterone as substrates. Though the activities of the two P-450(11 beta)s for 11-, 18-, and 19-hydroxylation of DOC were almost equal, the production of 18-hydroxycorticosterone and aldosterone from corticosterone by P-450(11 beta)-3 was greater than that by P-450(11 beta)-2.
Animals↗
Changes in insulin receptor kinase with aging in rat skeletal muscle and liver.
To see if insulin receptor kinase activity alters with aging, the activity of wheat germ agglutinin-purified receptor preparations from liver and skeletal muscle was compared in 2-, 4-, 10-, and 20-mo-old rats. Basal and insulin-stimulated autophosphorylation of liver insulin receptor and its kinase activities toward histone 2b and poly(Glu4Tyr1) did not alter with aging. On the other hand, the muscle insulin receptor showed different results. Insulin-stimulated increases of autophosphorylation and the kinase activity toward histone 2b above basal were comparable in the four groups. However, insulin-stimulated phosphorylation of poly(Glu4Tyr1) was decreased in 20-mo-old rats compared with 10- and 4-mo-old rats. These results indicate that insulin receptor kinase activity could vary under certain conditions, depending on the substrate used to measure the activity. It is concluded that insulin receptor kinase activity does not change markedly during the process of aging, although subtle changes seem to exist.
Adenosine Triphosphate↗
Efficacy and safety of catheter electrical ablation for ventricular tachycardia--experimental and clinical studies.
We studied the factors determining the extent of myocardial damage induced by catheter electrical ablation in 23 mongrel dogs and evaluated the efficacy and safety of catheter electrical ablation in 6 patients with medically refractory ventricular tachycardias (VT). Electrical shocks were delivered on the epicardium (EPI) and endocardium (END) of the ventricular wall of open-chest anesthetized dogs through a 6F USCI electrode catheter. Effect of the extent of electrode contact pressure was examined by the presence or absence of monophasic action potential using the contact electrode technique. The former was defined as the hard touch condition and the latter was defined as the soft touch condition. The myocardial lesion induced by EPI fulguration was larger than that by END fulguration (EPI-100 J soft touch: 10.2 +/- 2.9 mm in diameter, 6.6 +/- 1.6 mm in depth vs END-100 J soft touch: 7.7 +/- 1.7 mm in diameter, 5.0 +/- 1.2 mm in depth; p less than 0.05, p less than 0.05). The lesion diameter and lesion depth were enlarged by increasing the amount of delivered energy. The lesion depth by the hard touch condition was significantly greater than by the soft touch condition. The transmural perforation was observed in all EPI fulguration in the hard touch condition of the right ventricular wall. In the clinical study, one to three shocks (mean 1.8 +/- 0.7) of 60 to 200 J (mean 151 +/- 48 J) were delivered per session in 6 patients with medically refractory VT.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Effects of cultural conditions on hexavalent chromium uptake and the cytotoxicity thereof in KB cell culture].
To reveal the effects of cultural conditions on the cytotoxicity of hexavalent chromium, the uptake of sodium chromate (Na2CrO4) by KB cells and the colony-forming efficiency of the cells were examined under various cultural conditions. The results were summarized as follows: 1) The chromium uptake by the cells after a certain period of incubation with hexavalent chromium was inhibited with the decrease of the temperature (3 degrees, 20 degrees, 37 degrees C), increase of the serum concentration (0, 10, 20, 30%) and increase of pH (6.8-8.2) of the medium. In particular, low temperatures inhibited the chromium uptake by the cells remarkably. However, in relation to the serum addition, no marked effect was found. 2) The chromium uptake by the cells increased with the volume of the medium containing an identical concentration of chromium (2 ppm) and then reached saturation when it was about 0.23 microgram per 10(6) cells. On the other hand, the chromium uptake positively correlated with the concentration of chromium and the total chromium in the medium. 3) The difference of chromium uptake by the cells in different culture media was more marked at acidic pH than that at alkaline pH. However, there was no effect of calcium chloride and glucose concentrations on the uptake of chromium. The chromium uptake by the cells in Ca-Mg-free phosphate-buffered solution (PBS(-] was higher than that in other culture media. Consequently, the above results suggested that the chromium uptake by the KB cells might be affected by the various cultural conditions, especially by temperature, pH and medium volume.
Cations↗
Low susceptibility of the laboratory-reared Afghan pika, Ochotona rufescens rufescens to Haemonchus contortus.
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Animals↗
[Cleaning of Sendai virus-infected mice by embryo transfer technique].
Mouse embryos (8-16 cells) were collected from Sendai virus (SV)-infected mice at 5 or 7 weeks after inoculation. All donors having embryo(s) were positive when tested by CF test or ELISA for SV antibody at the time of embryo collection. Most of the morphologically normal embryos developed (90.6%, 259/286) to morulae or blastocysts after culture for 26-28 hr. A total of 76 embryos cultured were transferred to the uteri of SV-free pseudopregnant recipients. Forty-seven young were obtained from these recipients (61.8% of development rate) and 46 young were successfully reared up to 10th week of age. All the recipients and the young were negative by testing SV antibody. These results indicate that the embryo transfer technique is useful for cleaning of SV-infected mice.
Animals↗