Phylogenetic and phylodynamic analyses of hepatitis C virus subtype 1a in Okinawa, Japan.

Okinawa Island, located in Southern Japan, has a higher prevalence rate of hepatitis C virus subtype 1a (HCV-1a) infection than that in mainland Japan. Okinawa has a history of US military occupation after World War II. To elucidate the transmission history of HCV-1a in Okinawa, 26 whole-genome sequences were obtained from 29 patients during 2011-2016. Phylogenetic trees were reconstructed to identify the origin and characteristics of HCV-1a in Okinawa with epidemiological information. A phylogenetic tree based on whole-genome sequencing revealed that all of the samples were located below the US branches. Additionally, we identified one cluster comprised of 17 strains (Okinawa, n = 16; United States, n = 1). The majority of the patients in this cluster were people who inject drugs (PWID), indicating the presence of a people who inject drugs (PWID) cluster. Subsequently, Bayesian analyses were employed to reveal viral population dynamics. Intriguingly, a phylodynamic analysis uncovered a substantial increase in effective population size of HCV-1a from 1965 to 1980 and a slight increase in mid-2000, which were associated with an increase in illicit drug use in Okinawa. The estimated divergence time of the PWID cluster was 1967.6 (1964.2-1971.1). These findings suggest that HCV-1a was introduced into Okinawa from the United States in the late 1960s, coincident with the Vietnam War. Subsequently, HCV-1a might have spread among the Japanese population with the spread of injecting drug use. Our study provides an understanding of HCV transmission dynamics in Okinawa, as well as the key role of PWID in HCV transmission.

Biphasic action of aldosterone on Akt signaling in cardiomyocytes.

Both aldosterone and Akt signaling play pivotal roles in the pathogenesis of heart failure. However, little is known about the correlation between them. We herein investigated whether aldosterone interacts with Akt signaling in a coordinated manner in cardiomyocytes. Neonatal rat cardiomyocytes were stimulated with aldosterone for either a short (10-min) or long (24-h) time. The phosphorylation of Akt and its downstream effector, GSK3ß, were transiently increased after short-term stimulation, which was blocked by either PI3K or Na(+)/H(+) exchanger inhibitors, but not by the mineralocorticoid receptor antagonist, eplerenone. Long-term stimulation also significantly increased Akt-GSK3ß phosphorylation and this effect was reduced by eplerenone. Thus, these results suggest that aldosterone activates Akt signaling via a biphasic reaction that occurs through different cascades. To understand the significance of the rapid action of aldosterone, cardiomyocytes were exposed to hydrogen peroxide for from 10 to 60 min. A short-term aldosterone stimulation (for up to 30 min) significantly protected cardiomyocytes from oxidative stress-induced cellular damage. Eplerenone did not abrogate this beneficial effect, while a PI3K inhibitor did. Therefore, during the early phase, aldosterone has favorable effects on cardiomyocytes, partly by acute activation of a mineralocorticoid receptor-independent cascade through the Na(+)/H(+) exchanger, PI3K, and Akt. In contrast, its persistent activity produces pathological effects partly by chronic Akt activation in a mineralocorticoid receptor-dependent manner.

Tumor suppressor p53 binding protein 1 (53BP1) is involved in DNA damage-signaling pathways.

The tumor suppressor p53 binding protein 1 (53BP1) binds to the DNA-binding domain of p53 and enhances p53-mediated transcriptional activation. 53BP1 contains two breast cancer susceptibility gene 1 COOH terminus (BRCT) motifs, which are present in several proteins involved in DNA repair and/or DNA damage-signaling pathways. Thus, we investigated the potential role of 53BP1 in DNA damage-signaling pathways. Here, we report that 53BP1 becomes hyperphosphorylated and forms discrete nuclear foci in response to DNA damage. These foci colocalize at all time points with phosphorylated H2AX (gamma-H2AX), which has been previously demonstrated to localize at sites of DNA strand breaks. 53BP1 foci formation is not restricted to gamma-radiation but is also detected in response to UV radiation as well as hydroxyurea, camptothecin, etoposide, and methylmethanesulfonate treatment. Several observations suggest that 53BP1 is regulated by ataxia telangiectasia mutated (ATM) after DNA damage. First, ATM-deficient cells show no 53BP1 hyperphosphorylation and reduced 53BP1 foci formation in response to gamma-radiation compared with cells expressing wild-type ATM. Second, wortmannin treatment strongly inhibits gamma-radiation-induced hyperphosphorylation and foci formation of 53BP1. Third, 53BP1 is readily phosphorylated by ATM in vitro. Taken together, these results suggest that 53BP1 is an ATM substrate that is involved early in the DNA damage-signaling pathways in mammalian cells.

Anomalies of nanosecond ultrasonic relaxation in the lipid bilayer transition.

The frequency dependence of ultrasonic velocity as well as absorption in a suspension of sonicated dipalmitoylphosphatidylcholine vesicles was measured by a differential ultrasonic resonator. The frequency was scanned between 1.3 and 13 MHz and the temperature was varied from 25 to 47 degrees C. A pronounced relaxation was observed in the time range of 10 ns. The data were analyzed assuming a single relaxation which appeared to be a good approximation. The relaxation time as well as relaxation strength increased anomalously in the vicinity of the gel-to-liquid crystal transition of 41.5 degrees C. This result represents the first definite evidence of the critical slowing down in the lipid bilayer and is discussed in terms of the Landau theory of phase transition. The possible biological significance of the mechanical relaxation is also presented.

Molecular cloning of genes encoding major two subunits of a eubacterial V-type ATPase from Thermus thermophilus.

The atpAB genes which encode the alpha and beta subunits of membrane ATPase from a thermophilic eubacterium, Thermus thermophilus HB8, were cloned. The deduced amino-acid sequences of the alpha subunit (583 amino acids) and the beta subunit (478 amino acids) are only moderately similar to the alpha beta subunits of the F0F1-ATPases, while they are highly similar to the major two subunits of the V-type ATPases, a family of ATPases which have been so far found in eukaryotic endomembrane vacuolar vesicles and archaebacterial plasma membranes. Thus, T. thermophilus ATPase belongs to the V-type ATPase family, even though this bacterium is a eubacterium. The hypothesis that the differentiation of an ancestral ATPase into V-type and F0F1-ATPase occurred after the evolution of a primordial cell into archaebacteria and eubacteria should be modified accordingly.

Crystallization of 31 kDa C-terminal fragment of rat DNA polymerase beta.

A 248 residue C-terminal fragment of rat DNA polymerase beta (335 amino acid residues), a eukaryotic DNA repair enzyme, has been crystallized from polyethylene glycol 6000 solution. The crystals are orthorhombic, space group P2(1)2(1)2 with cell dimensions a = 120.3 A, b = 64.2 A, c = 39.4 A, and contain a single 31 kDa fragment in an asymmetric unit. The crystals diffract to 2.8 A resolution with laboratory X-ray source, and to 2.3 A resolution with synchrotron X-ray source, and are suitable for detailed structural analysis.

Impact of a training course on the quality of chest radiography to diagnose pulmonary tuberculosis.

SETTING: Socio-economically underprivileged urban areas in the Philippines. OBJECTIVE: To assess the performance of radiological technicians (RTs) 3 years after their participation in a training course to improve the quality of chest X-ray (CXR) and to test a monitoring visit after the course. DESIGN: A cross-sectional and observational study including on-site monitoring of X-ray facilities in Manila and Quezon City and assessment of CXR films taken by 23 RTs who previously attended a training course in 2009 or 2010. The sum of the assessment scores for each of six assessment factors at four points, i.e., before and after the training course that had been previously analysed, and before and after the monitoring visits that were currently analysed, were compared. RESULTS: Two assessment sum scores, identification mark or patient positioning, did not show significant differences. However, assessment of density, contrast, sharpness and artefact significantly improved after the training course, and before and after the monitoring visit, compared with before the training. There were no significant differences in any of the assessment factors before and after the monitoring visits. CONCLUSION: The training course appears to have had a long-term effect on maintaining CXR quality. The post-training monitoring visit did not significantly improve CXR quality.

Contexte : Zones urbaines de bas niveau socio-économique aux Philippines.Objectif : Evaluer la performance des manipulateurs radio (RT) dans les 3 années suivant leur participation à un cours de formation destiné à améliorer la qualité des radiographies pulmonaires (CXR) ainsi que l'effet d'une visite de suivi après le cours.Schéma : Etude transversale et d'observation incluant le suivi sur place des structures de radiographie à Manille et Quezon et l'évaluation des clichés de CXR pris par 23 RT qui avaient assisté au cours de formation en 2009 ou 2010. Les sommes des scores d'évaluation de chacun des six facteurs d'évaluation à quatre moments, c'est-à-dire avant et après le cours de formation qui avaient été évalués précédemment et avant et après les visites de suivi qui étaient en cours d'analyse, ont été comparées.Résultats : Deux sommes de scores d'évaluation­identification du cliché ou positionnement du patient­n'ont pas mis en évidence de différence significative. Cependant, en ce qui concerne la densité, le contraste, la définition et les artefacts, une amélioration significative a été constatée après le cours de formation et avant et après la visite de suivi, par comparaison avec les résultats préalables à la formation. Par contre, il n'y a eu de différence significative dans aucun des facteurs d'évaluation avant et après les visites de suivi.Conclusion : Le cours de formation a démontré un effet à long terme en termes de maintien de la qualité des RP. Par contre, la visite de suivi après la formation n'a pas significativement amélioré la qualité des RP.

Marco de referencia: Zonas urbanas en situación socioeconómica desfavorable en las Filipinas.Objetivo: Evaluar el desempeño de los auxiliares técnicos de radiología (RT) 3 años después de haber participado en un curso de capacitación destinado a mejorar la calidad de la radiografía de tórax (CXR) y la utilidad de una visita de supervisión después del curso.Métodos: Se llevó a cabo un estudio transversal y de observación, en el cual se realizó una supervisión directa de las instalaciones de radiología en Manila y Ciudad Quezón y se evaluaron las CXR realizadas por 23 auxiliares RT que habían atendido a un curso de capacitación en el 2009 o el 2010. Se calificaron seis criterios de calidad de las CXR y la suma de las puntuaciones de cada criterio se categorizó en cuatro niveles; se compararon las sumatorias de las puntuaciones en cada momento de evaluación antes y después de la capacitación y antes y después de las visitas de supervisión realizadas durante el estudio.Resultados: Las sumatorias de las puntuaciones de dos criterios­la marca de identificación y el posicionamiento del paciente­no exhibieron diferencias significativas en los diferentes momentos de evaluación. Sin embargo, las puntuaciones sobre la densidad, el contraste, la nitidez y la presencia de artefactos revelaron una mejoría significativa después de la capacitación y también antes y después de la visita de supervisión, comparadas con las calificaciones obtenidas antes del curso de capacitación. No se observaron diferencias significativas en los criterios de calidad evaluados antes y después de las visitas de supervisión.Conclusión: El curso de capacitación ofrece un efecto a largo plazo sobre el mantenimiento de la calidad de las CXR. Las visitas de supervisión posteriores al entrenamiento no tuvieron una repercusión importante sobre la calidad.

Enhancement of Fas ligand-induced inhibition of neointimal formation in rabbit femoral and iliac arteries by coexpression of p35.

Adenovirus-mediated gene transfer of Fas ligand (FasL) inhibits neointimal formation in balloon-injured rat carotid arteries. Vascular smooth muscle (VSM) cells coexpressing murine FasL and p35, a baculovirus gene that inhibits caspase activity, are not susceptible to FasL-mediated apoptosis in vitro but are capable of inducing apoptosis of VSM cells that do not express p35. We reasoned that coexpression of p35 in FasL-transduced VSM cells in vivo would promote their survival, enhance FasL-induced apoptosis of adjacent VSM cells, and thereby facilitate a greater inhibition of neointimal formation. In balloon-injured rabbit femoral arteries, either Ad2/FasL/p35 or Ad2/FasL was infused into the injured site and withdrawn 20 min later. Both vectors induced a dose-dependent reduction (p < 0.05) of the neointima-to-media ratio when assessed 14 days later. However, Ad2/FasL/p35 exhibited a significantly greater inhibition of neointimal formation than Ad2/FasL. In a more clinically relevant model of restenosis, rabbit iliac arteries were injured with an angioplasty catheter under fluoroscopic guidance. Adenoviral vectors were delivered locally to the injured site over a period of 2 min, using a porous infusion balloon catheter. Twenty-eight days after gene transfer angiographic and histologic assessments indicated a significant (p < 0.05) inhibition of iliac artery lumen stenosis and neointimal formation by Ad2/FasL/p35 (5 x 10(11) particles per artery). The extent of inhibition was comparable to that achieved with Ad2/TK, an adenoviral vector encoding thymidine kinase (5 x 10(11) particles per artery) and coadministration of ganciclovir for 7 days. These data suggest that coexpression of p35 in FasL-transduced VSM cells is more potent at inhibiting neointimal formation and as such represents an improved gene therapy approach for restenosis.

Construction of Escherichia coli vectors for expression and mutagenesis: synthesis of human c-Myc protein that is initiated at a non-AUG codon in exon 1.

Three types of Escherichia coli vector for both gene expression and mutagenesis were constructed from a plasmid/phage chimera vector pUC118. Each vector contains the lac (pTD-lac), tac (pTD-tac), or T7 promoter (pTD-T7). Downstream from the promoter, these vectors have sequences in common, including a Shine-Dalgarno (SD), multiple cloning sequence, sequence-primer binding site, transcription termination signal, and M13 origin of replication. Using single-stranded circular DNA obtained by infection with helper phage, oligodeoxyribonucleotide (oligo)-directed mutagenesis allows the appropriate fusion between the vector SD sequence and the start codon in the inserted fragment. Since a complementary oligo representing a large deletion is generally used for this construction, the extra nucleotides in the opposing strand form a loop structure. Thus, we have designated this mutagenesis as 'loop-out mutagenesis'. Expression plasmid encoding the larger human c-Myc protein that is initiated at a non-AUG codon in exon 1 and its derivatives were constructed using a pTD-T7 vector. Expression experiments indicated that the wild-type (wt) protein was synthesized poorly after induction with isopropyl-beta-D-thiogalactopyranoside, while one of the derivatives, p62M1T, in which a threonine residue was added at the N terminus of the wt protein, was produced in a large quantity in E. coli.

cDNA cloning and chromosomal mapping of genes encoding novel protein kinases termed PKU-alpha and PKU-beta, which have nuclear localization signal.

We have cloned cDNAs for novel serine/threonine protein kinases (PK), termed PKU-alpha and PKU-beta, by screening a bacteriophage expression library for kinase activity. Sequence analysis of PKU-alpha and PKU-beta genes revealed that their open reading frames (ORF) were 2151 and 2361 nucleotides (nt) encoding polypeptides of 717 and 787 amino acid (aa) residues, respectively. The deduced aa sequences of PKU-alpha and PKU-beta contained typical serine/threonine PK domains at the C-terminal region and were 86% identical to each other, indicating that they belong to the same PK family. Northern analysis reveals that they are expressed in nearly all human tissues and in cultured cells. The genes for PKU-alpha and PKU-beta were mapped to chromosome 17q23 and 8p12-p22, respectively, by fluorescence in situ hybridization. The proteins encoded by both cDNAs contain a putative nuclear localization signal (NLS) in their N-terminal region. These signals are likely to function in nuclear localization. Glutathione S-transferase (GST)-fusions to regions of PKU-alpha and beta containing the NLS were efficiently localized to the nucleus. In addition, PKU-beta transiently expressed in COS-1 cells was predominantly nuclear. PKU-alpha and PKU-beta differ: a consensus sequence for a nt binding motif is present near the NLS of PKU-beta. These results suggest that PKU-alpha and beta may phosphorylate serine and/or threonine residues on similar proteins, but their activities are regulated through distinct interactions with a nuclear component.

A DNA fragment homologous to F1-ATPase beta subunit was amplified from genomic DNA of Methanosarcina barkeri. Indication of an archaebacterial F-type ATPase.

A 490 bp DNA fragment was amplified from Methanosarcina barkeri genomic DNA by the polymerase chain reaction (PCR) using oligonucleotide primers designed based on conserved amino acid sequences of the F1-ATPase beta subunits. The amino acid sequence deduced from the DNA sequence of this fragment was highly homologous to a portion of the F1-ATPase beta subunit. This indicates that this archaebacterium has a gene of F-type ATPase in addition to a gene of V-type ATPase.

Synthesis of halogen-substituted 1,5-benzothiazepine derivatives and their vasodilating and hypotensive activities.

In an attempt to improve the effectiveness and duration of the action of diltiazem (1), a 1,5-benzothiazepine calcium channel blocker, its derivatives (2) with halogen substituents on the fused benzene ring were synthesized. These compounds were evaluated for their effects on vertebral and coronary blood flows and antihypertensive activity. The structure-activity relationships are discussed. The 8-chloro derivative ((+)-2b), the most potent compound in this series, was selected for clinical evaluation as a cerebral vasodilating and antihypertensive agent.

Polymorphism in ALDH2-genotype in Japanese men and the alcohol-blood pressure relationship.

Aldehyde dehydrogenase with a low Michaelis constant (Km), ALDH2, is a major enzyme involved in the conversion of acetaldehyde, a toxic metabolite of ethanol, into acetic acid in the liver. Inherited deficiency of ALDH2 activity is found in half of Japanese, and is characterized by "Oriental flushing" after alcohol consumption. The aim of the present study is to evaluate the influence of the genetic polymorphism in alcohol metabolism on the sensitivity to the pressor effect of alcohol. Genotypes of ALDH2 were determined in 403 middle-aged Japanese men using genomic DNA extracted from white blood cells. Two hundred and forty-three (60%) of the subjects were shown to be homozygotes for the normal ALDH2 gene, 25 (6%) of the subjects were homozygotes for the mutant ALDH2 gene, and the remaining 135 (33%) were heterozygotes. None of the homozygotes for the mutant gene drank enough to show the pressor effect of alcohol. Elevations of blood pressure associated with increasing alcohol consumption or with elevations of serum gamma-glutamyl transpeptide (GTP) level were not different between the other two ALDH2-genotypes. It can be concluded that polymorphism in the ALDH2-genotype found in Japanese men does not affect the individual sensitivity to the pressor effect of alcohol.

Studies on a thermophilic RNA polymerase which is active only on poly d(A-T) and poly dAdT.

Two types of RNA polymerases [EC 2.7.7.6], polymerases A and B, exist in thermophilic bacteria, Thermus thermophilus HB8. Polymerase B is apparently like the core enzyme of polymerase A but is active only when an alternating copolymer of deoxyadenylic and deoxythymidylic acids (poly d(A-T)) or a mixture of homopolymers of deoxyadenylic acid and deoxythymidylic acid (poly dAdT) is used as a template. Polymerase B was further characterized to elucidate its relation to polymerase A and to determine why it is inactive on natural DNA's. 1. Polymerase B did not show pyrophosphate exchange activity. Dinucleoside monophosphates did not activate the RNA-synthesizing activity. The results suggested that polymerase B had no initiation and presumably no elongation activities. 2. Polymerase B had about 6 times greater affinity to DNA than polymerase A. The binding of polymerase B to DNA was, however, reversible. The complex of DNA with polymerase A was stable and the polymerase was not removed from the initial complex even when a large amount of DNA was added. 3. E. coli sigma subunit could not stimulate the activity of polymerase B toward DNA's. 4. Polymerase B could utilize poly d(A-T) and poly dAdT as templates, but could not use Bacillus cereus DNA though the structure is reported to be similar to that of poly d(A-T).

Reconstituted F1-ATPase complexes containing one impaired beta subunit are ATPase-active.

Homogeneous populations of hybrid alpha 3 beta 3 gamma complexes of the thermostable F1-ATPase containing one, two, or three copies of the mutationally impaired beta subunits were produced using the solid phase reconstitution method. Two kinds of mutated beta subunits were used for the reconstitution, one of which lacked the ability to bind any adenine nucleotides. The complexes containing one impaired beta and two wild-type beta subunits retained a significant amount of ATPase activity with cooperative kinetics, whereas those containing two or three impaired beta subunits showed very little ATPase activity. These results imply that the catalysis of steady-state ATP hydrolysis can proceed even if one of the three beta subunits in F1-ATPase is not functional.

Orotate phosphoribosyltransferase from Thermus thermophilus: overexpression in Escherichia coli, purification and characterization.

Orotate phosphoribosyltransferase (OPRTase, EC2.4.2.10) plays a role in de novo synthesis of pyrimidine nucleotide and transfers orotate to 5-phosphoribosyl-1-pyrophosphate (PRPP) to form orotidine-5'-monophosphate (OMP). To obtain heat-stable OPRTase and to elucidate the mechanism of heat stability, this enzyme from Thermus thermophilus was expressed in Escherichia coli and purified. The pyrE gene of T. thermophilus which encodes OPRTase, contains an open reading frame of 549 base pairs with 69% G+C content. Since this gene expressed itself inefficiently in E. coli, the 5' and 3' ends of the coding regions were replaced with synonymous codons which contain more A+T and corresponds to major codons for E. coli. Introduction of the modified gene fragments into a plasmid having a tac promoter resulted in production of a polypeptide of molecular weight (M(r)) 20,000 in the presence of isopropyl-beta-D-thiogalactopyranoside (IPTG) in E. coli. This protein represented as much as 16% of the bacterial total protein and showed the OPRTase activity. Three purification steps, consisting of heat treatment at 65 degrees C, 40% ammonium sulfate fractionation, and KCl gradient elution from DEAE-Sephadex A-50, resulted in highly purified single polypeptide. The optimum activity of the purified OPRTase was observed at 150 mM KCl, pH 9.0, 75-80 degrees C, and in the presence of 100 microM PRPP. The activation energy of this enzyme reaction was 20.3 kJ/mol. The Km of this enzyme for orotate as a substrate was 75 microM and the maximum specific activity was 300 units/mg protein under the optimum conditions. The purified OPRTase was stable for 20 min at 85 degrees C.

A bandwidth indicator for magnetic resonance imagers.

Signal-to-noise ratios in magnetic resonance imaging are crucial in determining image quality, and dependent on a number of factors, one being the signal bandwidth per pixel. Not all manufacturers clearly state the bandwidth per pixel used for all sequences. A small battery-powered portable device is described which produces bright sharp lines on the magnetic resonance image at 10 kHz intervals in the frequency encoding direction. The bandwidth per pixel can then easily be calculated using electronic distance callipers, provided the image matrix and field of view are known. The device is expected to be especially of value when acceptance testing on poorly documented imaging systems.

Role of endogenous and exogenous cholesterol in liver as the precursor for bile acids in rats.

There is considerable evidence suggesting that compartmentalized functional pools of cholesterol in the liver contribute differently to the formation of bile acids as the precursor. The present paper deals with the incorporation of [1-14C] acetate and of [1,2-3H] cholesterol carried on lipoproteins (LDL and HDL) into biliary bile acids in perfused rat livers and bile-fistula rats. The results showed that endogenous cholesterol synthesized newly from [1-14C] acetate in the liver was incorporated into both cholic acid and chenodeoxycholic acid in a similar way, while exogenous lipoprotein-[1,2-3H) cholesterol delivered to hepatocytes from hepatic circulation was incorporated into chenodeoxycholic acid at a higher rate.

TMC-2A, -2B and -2C, new dipeptidyl peptidase IV inhibitors produced by Aspergillus oryzae A374. II. Isolation and structure determination.

New dipeptidyl peptidase IV inhibitors, TMC-2A, -2B, and -2C, were isolated from the fermentation broth of Aspergillus oryzae A374. On the basis of chemical, spectroscopic and X-ray crystallographic analyses, their structures were established to be peptide-like compounds composed of three moieties, L-tryptophan, mono- or dihydroxy-L-leucine and highly substituted isoquinoline.

[Determination of DNA binding domains in hepatitis C virus core protein].

OBJECTIVE: To determine the DNA binding domain in hepatitis C virus core protein and otelucidate the significance of binding. METHODS: Segments of hepatitis C virus core protein were expressed in E.coli as fusion forms with glutathion S-transferase (GST). The core proteins were immobilized in SDS-PAGE gel after removing SDS from the gel by washing. (32)P-ATP labeled oligonucleotides were electrophoresed through the gel in TAE buffer. The binding of DNA with core protein was detected by autoradiography. RESULTS: There were at least two DNA binding domains in the HCV core protein, the first locating at 10~16aa and the second at 46-70aa. The second region was divided into three adjacent parts, which could bind core protein independently. Core protein bound to single strand DNA as well as to double strand DNA without sequence specificity. CONCLUSIONS: DNA binding regions of HCV core protein locate at its N-terminus. The binding regions of HCV core protein overlap its nucleus transfer signals and they bind to target DNA unselectively, suggesting a possible mechanism for its multifunction. The result provides basic data for understanding the biological function of HCV core protein.