Homeostasis of metabolites in Escherichia coli on transition from anaerobic to aerobic conditions and the transient secretion of pyruvate

We have developed a method for rapid quenching of samples taken from chemostat cultures of Escherichia coli that gives reproducible and reliable measurements of extracellular and intracellular metabolites by 1H NMR and have applied it to study the major central metabolites during the transition from anaerobic to aerobic growth. Almost all metabolites showed a gradual change after perturbation with air, consistent with immediate inhibition of pyruvate formate-lyase, dilution of overflow metabolites and induction of aerobic enzymes. Surprisingly, although pyruvate showed almost no change in intracellular concentration, the extracellular concentration transiently increased. The absence of intracellular accumulation of pyruvate suggested that one or more glycolytic enzymes might relocate to the cell membrane. To test this hypothesis, chromosomal pyruvate kinase (pykF) was modified to express either PykF-green fluorescent protein or PykF-FLAG fusion proteins. Measurements showed that PykF-FLAG relocates to the cell membrane within 5 min of aeration and then slowly returns to the cytoplasm, suggesting that on aeration, PykF associates with the membrane to facilitate secretion of pyruvate to maintain constant intracellular levels

Essential pre-treatment imaging examinations in patients with endoscopically-diagnosed early gastric cancer

<p>Abstract</p> <p>Background</p> <p>There have been no reports discussing which imaging procedures are truly necessary before treatment of endoscopically-diagnosed early gastric cancer (eEGC). The aim of this pilot study was to show which imaging examinations are essential to select indicated treatment or appropriate strategy in patients with eEGC.</p> <p>Methods</p> <p>In 140 consecutive patients (95 men, 45 women; age, 66.4 +/- 11.3 years [mean +/- standard deviation], range, 33-90) with eEGC which were diagnosed during two years, the pre-treatment results of ultrasonography (US) and contrast-enhanced computed tomography (CT) of the abdomen, barium enema (BE) and chest radiography (CR) were retrospectively reviewed. Useful findings that might affect indication or strategy were evaluated.</p> <p>Results</p> <p>US demonstrated useful findings in 13 of 140 patients (9.3%): biliary tract stones (n = 11) and other malignant tumors (n = 2). Only one useful finding was demonstrated on CT (pancreatic intraductal papillary mucinous tumor) but not on US (0.7%; 95% confidential interval [CI], 2.1%). BE demonstrated colorectal carcinomas in six patients and polyps in 10 patients, altering treatment strategy (11.4%; 95%CI, 6.1-16.7%). Of these, only two colorectal carcinomas were detected on CT. CR showed three relevant findings (2.1%): pulmonary carcinoma (n = 1) and cardiomegaly (n = 2). Seventy-nine patients (56%) were treated surgically and 56 patients were treated by endoscopic intervention. The remaining five patients received no treatment due to various reasons.</p> <p>Conclusions</p> <p>US, BE and CR may be essential as pre-treatment imaging examinations because they occasionally detect findings which affect treatment indication and strategy, although abdominal contrast-enhanced CT rarely provide additional information.</p

Association between physical activity and metabolic syndrome in middle-aged Japanese: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Although many studies have reported an association between self-reported physical activity and metabolic syndrome (MetS), there is limited information on the optimal level of physical activity required to prevent MetS. This study aimed to determine the association between objectively measured physical activity and MetS in middle-aged Japanese individuals. We also determined the optimal cutoff value for physical activity required to decrease the risk of developing MetS.</p> <p>Methods</p> <p>A total of 179 men and 304 women, aged between 30 and 64 years, participated in this study. Participants were divided into two groups using the Japanese criteria for MetS as those with MetS or pre-MetS, and those without MetS. Participants were considered to be physically active if they achieved a physical activity level of 23 metabolic equivalents (METs) h/week, measured using a triaxial accelerometer. The association between physical activity and MetS was analyzed using logistic regression with the following covariates: sex, age, sedentary time, low intensity activity, calorie intake, smoking, menopause and body mass index. We also evaluated the factors that determined the association between the prevalence of MetS and pre-MetS and the physical activity cutoff value using classification and regression tree (CART) analysis.</p> <p>Results</p> <p>The odds ratio for MetS and pre-MetS was 2.20 for physically inactive participants (< 23 METs h/week), compared with physically active participants (≥ 23 METs h/week). The corresponding odds ratios for men and women were 2.27 (<it>P </it>< 0.01) and 1.95 (not significant), respectively. CART analyses revealed that moderate-vigorous physical activity of > 26.5 METs h/week was sufficient to decrease the prevalence of MetS and pre-MetS in middle-aged Japanese men and women.</p> <p>Conclusions</p> <p>The results of this cross-sectional study indicate that the Exercise and Physical Activity Reference for Health Promotion 2006 is inversely associated with the prevalence of MetS in men. Our results also suggest that moderate physical activity of > 26.5 METs h/week may decrease the risk of developing MetS and pre-MetS in middle-aged Japanese individuals.</p

A comparative population-based study of prostate cancer incidence and mortality rates in Singapore, Sweden and Geneva, Switzerland from 1973 to 2006

10.1186/1471-2407-12-222BMC Cancer12-BCMA

Synthesis and Magnetic Properties of Maghemite (γ-Fe2O3) Short-Nanotubes

We report a rational synthesis of maghemite (γ-Fe2O3) short-nanotubes (SNTs) by a convenient hydrothermal method and subsequent annealing process. The structure, shape, and magnetic properties of the SNTs were investigated. Room-temperature and low-temperature magnetic measurements show that the as-fabricated γ-Fe2O3 SNTs are ferromagnetic, and its coercivity is nonzero when the temperature above blocking temperature (TB). The hysteresis loop was operated to show that the magnetic properties of γ-Fe2O3 SNTs are strongly influenced by the morphology of the crystal. The unique magnetic behaviors were interpreted by the competition of the demagnetization energy of quasi-one-dimensional nanostructures and the magnetocrystalline anisotropy energy of particles in SNTs

Innate Immune Responses to Bacterial Ligands in the Peripheral Human Lung – Role of Alveolar Epithelial TLR Expression and Signalling

It is widely believed that the alveolar epithelium is unresponsive to LPS, in the absence of serum, due to low expression of TLR4 and CD14. Furthermore, the responsiveness of the epithelium to TLR-2 ligands is also poorly understood. We hypothesised that human alveolar type I (ATI) and type II (ATII) epithelial cells were responsive to TLR2 and TLR4 ligands (MALP-2 and LPS respectively), expressed the necessary TLRs and co-receptors (CD14 and MD2) and released distinct profiles of cytokines via differential activation of MAP kinases. Primary ATII cells and alveolar macrophages and an immortalised ATI cell line (TT1) elicited CD14 and MD2-dependent responses to LPS which did not require the addition of exogenous soluble CD14. TT1 and primary ATII cells expressed CD14 whereas A549 cells did not, as confirmed by flow cytometry. Following LPS and MALP-2 exposure, macrophages and ATII cells released significant amounts of TNFα, IL-8 and MCP-1 whereas TT1 cells only released IL-8 and MCP-1. P38, ERK and JNK were involved in MALP-2 and LPS-induced cytokine release from all three cell types. However, ERK and JNK were significantly more important than p38 in cytokine release from macrophages whereas all three were similarly involved in LPS-induced mediator release from TT1 cells. In ATII cells, JNK was significantly more important than p38 and ERK in LPS-induced MCP-1 release. MALP-2 and LPS exposure stimulated TLR4 protein expression in all three cell types; significantly more so in ATII cells than macrophages and TT1 cells. In conclusion, this is the first study describing the expression of CD14 on, and TLR2 and 4 signalling in, primary human ATII cells and ATI cells; suggesting that differential activation of MAP kinases, cytokine secretion and TLR4 expression by the alveolar epithelium and macrophages is important in orchestrating a co-ordinated response to inhaled pathogens

Thermoregulation of Capsule Production by Streptococcus pyogenes

The capsule of Streptococcus pyogenes serves as an adhesin as well as an anti-phagocytic factor by binding to CD44 on keratinocytes of the pharyngeal mucosa and the skin, the main entry sites of the pathogen. We discovered that S. pyogenes HSC5 and MGAS315 strains are further thermoregulated for capsule production at a post-transcriptional level in addition to the transcriptional regulation by the CovRS two-component regulatory system. When the transcription of the hasABC capsular biosynthetic locus was de-repressed through mutation of the covRS system, the two strains, which have been used for pathogenesis studies in the laboratory, exhibited markedly increased capsule production at sub-body temperature. Employing transposon mutagenesis, we found that CvfA, a previously identified membrane-associated endoribonuclease, is required for the thermoregulation of capsule synthesis. The mutation of the cvfA gene conferred increased capsule production regardless of temperature. However, the amount of the capsule transcript was not changed by the mutation, indicating that a post-transcriptional regulator mediates between CvfA and thermoregulated capsule production. When we tested naturally occurring invasive mucoid strains, a high percentage (11/53, 21%) of the strains exhibited thermoregulated capsule production. As expected, the mucoid phenotype of these strains at sub-body temperature was due to mutations within the chromosomal covRS genes. Capsule thermoregulation that exhibits high capsule production at lower temperatures that occur on the skin or mucosal surface potentially confers better capability of adhesion and invasion when S. pyogenes penetrates the epithelial surface

Genetic Variants of Human Granzyme B Predict Transplant Outcomes after HLA Matched Unrelated Bone Marrow Transplantation for Myeloid Malignancies

Serine protease granzyme B plays important roles in infections, autoimmunity, transplant rejection, and antitumor immunity. A triple-mutated granzyme B variant that encodes three amino substitutions (Q48R, P88A, and Y245H) has been reported to have altered biological functions. In the polymorphism rs8192917 (2364A>G), the A and G alleles represent wild type QPY and RAH mutant variants, respectively. In this study, we analyzed the impact of granzyme B polymorphisms on transplant outcomes in recipients undergoing unrelated HLA-fully matched T-cell-replete bone marrow transplantation (BMT) through the Japan Donor Marrow Program. The granzyme B genotypes were retrospectively analyzed in a cohort of 613 pairs of recipients with hematological malignancies and their unrelated donors. In patients with myeloid malignancies consisting of acute myeloid leukemia and myelodysplastic syndrome, the donor G/G or A/G genotype was associated with improved overall survival (OS; adjusted hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.41–0.89; P = 0.01) as well as transplant related mortality (TRM; adjusted HR, 0.48; 95% CI, 0.27–0.86, P = 0.01). The recipient G/G or A/G genotype was associated with a better OS (adjusted HR, 0.68; 95% CI, 0.47–0.99; P = 0.05) and a trend toward a reduced TRM (adjusted HR, 0.61; 95% CI, 0.35–1.06; P = 0.08). Granzyme B polymorphism did not have any effect on the transplant outcomes in patients with lymphoid malignancies consisting of acute lymphoid leukemia and malignant lymphoma. These data suggest that there is an association between the granzyme B genotype and better clinical outcomes in patients with myeloid malignancies after unrelated BMT

A Multicentre Molecular Analysis of Hepatitis B and Blood-Borne Virus Coinfections in Viet Nam

Hepatitis B (HBV) infection is endemic in Viet Nam, with up to 8.4 million individuals estimated to be chronically infected. We describe results of a large, multicentre seroepidemiological and molecular study of the prevalence of HBV infection and blood-borne viral coinfections in Viet Nam. Individuals with varying risk factors for infection (n = 8654) were recruited from five centres; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. A mean prevalence rate of 10.7% was observed and levels of HBsAg were significantly higher in injecting drug users (IDUs) (17.4%, n = 174/1000) and dialysis patients (14.3%, n = 82/575) than in lower-risk groups (9.4%; p<0.001). Coinfection with HIV was seen in 28% of HBV-infected IDUs (n = 49/174) and 15.2% of commercial sex workers (CSWs; n = 15/99). HCV infection was present in 89.8% of the HBV-HIV coinfected IDUs (n = 44/49) and 40% of HBV-HIV coinfected CSWs (n = 16/40). Anti-HDV was detected in 10.7% (n = 34/318) of HBsAg positive individuals. Phylogenetic analysis of HBV S gene (n = 187) showed a predominance of genotype B4 (82.6%); genotypes C1 (14.6%), B2 (2.7%) and C5 (0.5%) were also identified. The precore mutation G1896A was identified in 35% of all specimens, and was more frequently observed in genotype B (41%) than genotype C (3%; p<0.0001). In the immunodominant ‘a’ region of the surface gene, point mutations were identified in 31% (n = 58/187) of sequences, and 2.2% (n = 4/187) and 5.3% (n = 10/187) specimens contained the major vaccine escape mutations G145A/R and P120L/Q/S/T, respectively. 368 HBsAg positive individuals were genotyped for the IL28B SNP rs12979860 and no significant association between the IL28B SNP and clearance of HBsAg, HBV viral load or HBeAg was observed. This study confirms the high prevalence of HBV infection in Viet Nam and also highlights the significant levels of blood-borne virus coinfections, which have important implications for hepatitis-related morbidity and development of effective management strategies