Nucleotide sequence of a metallothionein gene of the thermophilic cyanobacterium Synechococcus vulcanus.
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Biomedical subjects
Publications and source records attributed to Y Inoue.
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The purpose of this study was to evaluate the attached-X method compared with the standard Basc method, and, using this method, to find out whether the observed differences in genetic polymorphisms are related to differences in lethal mutation rates in D. melanogaster and D. simulans. When EMS-treated Drosophila melanogaster males are mated to untreated attached-X females, a decrease in the progeny sex ratio (male/female + male) is observed due to the induced lethal mutations on the X chromosome. The decrease in the frequency of male progeny were shown as the attached-X index. The expected male number is calculated from the control sex ratio. The difference between the expected and the observed male numbers, expressed as the ratio to the expected male number, defines the attached-X index. The index values for various EMS concentrations were compared to the lethal frequencies obtained by the standard Basc method for the same EMS treatments, and gave a highly positive correlation (gamma = 0.993, p < 0.01, d.f. = 2), thus providing an alternative method for evaluation of possible mutagens. The attached-X method was applied to D. simulans, of which natural populations are known to have relatively low genetic variation, and frequencies of the EMS-induced X chromosome lethal mutations were estimated and compared with those in D. melanogaster. The results indicate that D. melanogaster is slightly more sensitive in the sperm and spermatogonial stages, but less susceptible in the spermatid stage when compared with D. simulans.(ABSTRACT TRUNCATED AT 250 WORDS)
Contrast-enhanced magnetic resonance images (MRI) of three patients with subdural (SDE) and two with epidural empyemas (EDE) were reviewed. In each case, the capsule of the lesion demonstrated enhancement, and distinction between capsule and contents was obvious on contrast-enhanced images. In SDE, contrast-enhanced images clearly depicted thickening of the neighbouring dura mater and a co-existent brain abscess. In EDE, part of the displaced dura mater did not enhance, which facilitated differentiation from SDE. Contrast-enhanced MRI was thus of value in diagnosis.
Nine young (20-25 years) and ten older (60-71 years) men, matched for body fatness and surface area:mass ratio, underwent cold tests in summer and winter. The cold tests consisted of a 60-min exposure, wearing only swimming trunks, to an air temperature of 17 degrees C (both seasons) and 12 degrees C (winter only). Rectal (Tre) and mean skin (Tsk) temperatures, metabolic heat production (M), systolic (BPs) and diastolic (BPd) blood pressures and heart rate (fc) were measured. During the equilibrium period (28 degrees C air temperature) there were no age-related differences in Tre, Tsk, BPs, BPd, or fc regardless of season, although M of the older men was significantly lower (P < 0.003). The decrease in Tre and Tsk (due to the marked decrease in six of the older men) and the increase in BPs and BPd were significantly greater (P < 0.004) for the older men during all the cold exposures. The rate of increase in M was significantly greater (P < 0.01) for the older group when exposed to 12 degrees C in winter and 17 degrees C in summer (due to the marked increase in four of the older men). This trend was not apparent during the 17 degrees C exposure in winter. There was no age-related difference in fc during the exposures. Significant decreases in Tre and Tsk and increases in M, BPs and BPd during the 12 degrees C exposure were observed for the older group (P < 0.003) compared to their responses during the 17 degrees C exposure in winter. In contrast, Tre, M, BPs in the young group were not affected as much by the colder environment. It was concluded that older men have more variable responses and some appear more or less responsive to mild and moderate cold air than young men.
Adventitial cystic degeneration of the popliteal artery is seldom encountered; only 39 cases have been reported up to now in Japan. The pathogenesis of this disease remains controversial, and the authors describe a case in which the pathological findings differed from cases reported in the previous literature. The subject was a 74-year-old man admitted to our hospital complaining of intermittent claudication. The characteristic findings of cystic degeneration of the popliteal artery were uncovered by contrast-enhanced computed tomography (CT) and duplex sonography. The contrast-enhanced CT showed a low-density area and duplex sonography revealed a multi-lobulated low-echoic lesion. The Doppler signal of the low-echoic lesion could not be detected. While some cysts were found in the adventitia, they were mainly located in the media. The media also showed a remarkable decrease of smooth muscle cells and a prominent mucinous degeneration that had occurred circumferentially. These findings suggest that the medial degeneration noted had occurred prior to cystic formation. Because of this and other findings, we recommend the use of the term cystic degeneration of the popliteal artery in addition to the term cystic adventitial disease of the popliteal artery.
We have evaluated methods for separation, preparation, and characterization of alpha-2----8-linked oligomers of sialic acids (Neu5Ac and Neu5Gc) and deaminated neuraminic acid (KDN; 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid) recently found as a naturally occurring novel type of sialic acid analogue. (A) We examined preparative anion-exchange chromatography for fractionation and preparation of oligo(Neu5Ac), oligo(Neu5Gc), and oligo(KDN). (B) We also examined the TLC method for separation and differentiation of the partial acid hydrolysates of colominic acid, as well as polysialoglycoproteins (PSGP) and poly(KDN)-glycoproteins (KDN-gp) isolated from rainbow trout eggs, and for discrimination of lower oligomers of Neu5Ac, Neu5Gc, and KDN. (C) We developed the high-performance adsorption-partition chromatographic method for (a) separation of monomers and oligomers of three nonulosonates according to the difference in substituents at C-5 and the presence or absence of 9-O-acetyl groups in oligo(KDN) and (b) separation of three homologous series of lower oligomers according to the degree of polymerization. (D) We examined and compared high-performance anion-exchange chromatographic separation of 3H-labeled oligo(Neu5Ac), oligo(Neu5Gc), and oligo(KDN) alditols by using Mono-Q HR 5/5 resin. (E) We examined a method of selective and quantitative microprecipitation for separation and purification of oligomers and polymers of Neu5Ac by treating them with cetylpyridinium chloride. We also used PSGP and KDN-gp to test both the sensitivity and the selectivity of this method.
In 1986 we reported the natural occurrence of deaminated neuraminic acid (2-keto-3-deoxy-D-glycero-D-galactonononic acid, KDN) in fish egg glycoprotein. Subsequently, we have shown that many types of sialic acid as well as KDN occur in polymeric chains, poly(oligo)-Sia and poly(oligo)KDN in nature. In this study we demonstrate that the conventional colorimetric and gas-liquid chromatographic methods used in the analysis of sialic acid can be applied to analysis of these new nonulosonate and poly(oligo)nonulosonates. We report that the thiobarbituric acid reaction can be used to analyze both free and bound KDN, but gives lower extinction values when applied to poly(oligo)KDN without prior hydrolysis. Further, the published hydrolytic and/or methanolytic procedures are suitable to release the terminal sialic acid residues, but are not appropriate for quantitative release of the nonulosonic acids from poly(oligo)nonulosonates. A new gas-liquid chromatographic procedure for the identification-quantitation of nonulosonates in poly(oligo)meric forms is described.
The disaccharide trehalose extensively exists in anhydrobiotic organism and is considered to play an important role in preserving the integrity of biomembrane. However, the preserving mechanism remains unclear. In this report, we examine the hydration abilities of trehalose and several oligosaccharides composed of alpha-D-glucopyranosyl residues. The unfrozen water fraction per molecule was determined from differential scanning calorimetry measurements of their aqueous solutions. Further, the NMR relaxation time of the natural abundance 17O of water is measured for several saccharide solutions. These results indicate that trehalose has the highest hydration ability among the saccharides studied. In other words, trehalose can effectively lower the mobility of water molecules hydrogen-bonded with saccharides. It is thus reasonable that, among the disaccharides studied, trehalose exhibits the maximum stabilizing effect on the bilayer structure of lipid whose acyl chains are bonded with each other by the apolar interaction, because the apolar interaction is strengthened with the stabilization of the surrounding water structure.
An unusual case of a giant prolactinoma extending to the nasopharynx and nasal cavity is presented. A 35-year-old man admitted for nasal obstruction and visual disturbances was found to have bilateral anosmia, right homonymous hemianopsia, and a right hemiparesis. The serum prolactin level was 13,300 ng/mL. Radiological examination revealed a large mass invading the skull base and extending into the suprasellar region and the left frontal lobe superiorly and into the nasopharynx inferiorly. Subtotal removal was done through a bilateral orbitofrontal craniotomy, which was followed by radiotherapy and bromocriptine administration. Immunohistochemical analysis confirmed a prolactinoma. The rarity of such a tumor, its location and extension, and the usefulness of magnetic resonance imaging and immunohistochemistry are stressed. Pertinent literature is reviewed.
To assess the role of sulfidopeptide leukotrienes in the pathogenesis of exercise-induced asthma (EIA), the urinary levels of leukotriene E4 (LTE4), a metabolite of LTC4 and LTD4, were measured by RIA before and after exercise in 13 children with EIA and 10 healthy children. Mass spectrometry was used to confirm the presence of LTE4 in urine and the specificity of the RIA. There was no significant difference in the urinary LTE4 levels before exercise between the children with asthma and healthy children (109 [21 to 265] versus 122 [45 to 156] pg/mg of creatinine; median and range). Urinary LTE4 levels increased significantly after exercise in the children with EIA (from 109 [21 to 265] to 196 [40 to 655] pg/mg of creatinine; median and range; p less than 0.05) but not in the healthy children. The children with asthma demonstrated no significant correlation between the LTE4 level after exercise and the degree of bronchoconstriction, as revealed by the maximal percent fall in the peak expiratory flow rate. Taken together with a recent study that pretreatment with a potent and selective LTD4 antagonist markedly attenuated EIA, our findings suggest that sulfidopeptide leukotrienes may play some role in the pathogenesis of this type of asthma with other factors also being involved in determining the overall airway response.
Alcaligenes eutrophus H16 was grown on mixtures of 1H- and 2H-acetate as carbon sources. The accumulation of deuterated poly(3-hydroxybutyrate) (P(3HB)) was observed. The deuterium distributions in the isolated P(3HB)s were determined from 1H and 2H-n.m.r. spectra and confirmed by 13C-n.m.r. spectra. Although one would expect to synthesize P([2,2,4,4,4-2H5]3HB) when the cells were grown on 2H-acetate as the sole carbon source, the methyl, methylene and methine groups of the P(3HB) contained both deuterium and proton. This observation indicates some substitution from 2H to 1H during the P(3HB) synthesis. The 2H content in the methyl groups was larger than that in the methylene groups, which suggests a kinetic isotope effect in the P(3HB) synthesizing process. The deuterium distributions in the two magnetically non-equivalent methylene protons were determined to be different, which indicates stereoselectivity at the C2 site.
A series of copolyesters of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) was biosynthesized by Alcaligenes eutrophus from an amino acid, threonine. The 3HV content of these polyesters ranged from less than 0.1% to 30%.
A new method was developed for analysis of biodegradable polyesters, which involves alkali hydrolysis of polyesters to the corresponding hydroxyacids and determination of the hydroxyacids by high-performance liquid chromatography. It can be used to monitor weight change in polyesters and change in molecular ratio of the hydroxyacid constituents of polyesters during in vitro and in vivo degradation.
N-Methyl-D-aspartate (NMDA) receptors were expressed in Xenopus oocytes by injecting rat brain mRNA. NMDA-elicited responses in the oocytes were measured by the voltage-clamping method. The following measurements were made in the presence of 50 microM glycine (Gly) to establish the relationship between the NMDA concentration and the current: (1) the NMDA-induced membrane current before desensitization; (2) the NMDA-induced membrane current after desensitization equilibrium; (3) the fraction of the active form of the receptor after desensitization equilibrium in the presence and absence of 50 microM Gly; (4) the rate of the recovery of desensitized receptors upon removal of NMDA. Gly was essential for not only the activation of NMDA receptors but also their desensitization. These results were analyzed on the basis of a minimal model where one agonist and one Gly binding site were assumed. The equilibrium and rate constants of the model were evaluated for NMDA in the presence of saturating amounts of Gly. This model will be useful for systematically explaining the complicated responses of NMDA receptors.
To establish a standard protocol for an in vivo-in vitro hepatocyte replicative DNA synthesis (RDS) test using male F344 rats for screening nongenotoxic (the Ames-negative) hepatocarcinogens, experimental conditions were examined. After treatment with three model hepatocarcinogens, isolated hepatocytes showed highest RDS incidences when plated at a density of 5 x 10(4) cells/ml. Spontaneous RDS incidences in hepatocytes from rats aged 9 weeks or older showed a constant value. The use of hepatocytes from 9-week-old rats at the 5 x 10(4) cells/ml plating density was therefore determined as the standard. Based on the distribution of mean spontaneous RDS incidences over 105 additional experiments (0.4 +/- 0.18%, with SEM), an RDS incidence of over 1% was adopted as the criterion for a positive response in our rat liver RDS test.
To better establish in vivo-in vitro hepatocyte replicative DNA synthesis (RDS) test using male F344 rats as a screening assay for nongenotoxic (the Ames-negative) hepatocarcinogens, judgement criteria were assessed after single-gavage treatment with seven model compounds. The profiles of RDS induction by the compounds were analysed in terms of both time-course and dose-dependence. Our data reveal that a value of 2% or more for RDS incidence should be judged as positive and that of less than 1% RDS incidence as negative using maximum tolerance dose (MTD) concentrations in time-course experiments at 15, 24, 39, 48 and 63 h. In the case of an incidence value between 1 and 2%, the finding of a clear dose-dependence was considered to justify the conclusion of a positive effect for 1/4 MTD, 1/2 MTD, MTD and 2 x MTD at a fixed time. The established judgement criteria are planned for introduction in detection of nongenotoxic hepatocarcinogens (the Ames-negative carcinogens) using the RDS test.
A computer network system has been developed in the Orthodontic Clinic, Osaka University Dental Hospital, to improve treatment efficiency and patient service. The system consists of a 32-bit host computer, its peripheral units, and personal computers connected to the host computer by data-transmission circuits, making up a local area network (LAN). It is possible in this system to integrate various types of data, such as the patient's basic information, treatment records, image data, and diagnostic analysis results to construct a relational database. It has been shown that the computer system developed in the orthodontic clinic has various clinical advantages.
In order to investigate the structural properties of the sugar and peptide linkage region in glycoprotein, some glycopeptides were synthesized as a model for AFGP (antifreeze glycoprotein), which is one of the mucin-type glycoproteins. The results from n.m.r. measurements in DMSO and aqueous conditions revealed that the glycopeptides form an intramolecular hydrogen bond between the amide proton of N-acetylgalactosamine (GalNAc) and the carbonyl oxygen of threonine (Thr) to which the GalNAc is covalently linked. This intramolecular hydrogen bond may play an important role in determining the orientation of the sugar moiety relative to the protein backbone. The roles for the activity of the proline (Pro) residue in AFGP were also discussed.