Degree of ketonaemia and its association with insulin resistance after dapagliflozin treatment in type 2 diabetes.

BACKGROUND: Euglycaemic ketoacidosis has been reported after sodium-glucose cotransporter 2 (SGLT2) inhibitor treatment. However, the degree of ketonaemia and its metabolic effects have not been well investigated. Our study examined the degree of ketonaemia induced by SGLT2 inhibition and its association with metabolic profiles in type 2 diabetes mellitus (T2DM). METHODS: Biochemical parameters, including insulin, glucagon, free fatty acid (FFA), ß-hydroxybutyrate (BHB) and acetoacetate (ACA) levels, were measured in 119 T2DM patients after dapagliflozin treatment for>3 months, and compared with a matched control group. RESULTS: Levels of total ketones, BHB and ACA were significantly higher in the dapagliflozin group than in the control group: 283.7±311.0 vs 119.8±143.8µmol/L; 188.3±226.6 vs 78.0±106.7µmol/L; and 94.1±91.3 vs 41.8±39.1µmol/L, respectively (all P<0.001). After dapagliflozin treatment, BHB was higher than the upper limit of normal (>440µmol/L) in 13 (10.9%) patients who had no relevant symptoms. BHB level after dapagliflozin treatment correlated positively with HbA1c (r=0.280), FFA levels (r=0.596) and QUICKI (r=0.238), and negatively with BMI (r=-0.222), insulin-to-glucagon ratio (r=-0.199) and HOMA-IR (r=-0.205; all P<0.05). On multivariable linear regression analysis, QUICKI was independently associated with BHB level. CONCLUSION: Ketone levels were higher in T2DM patients treated with dapagliflozin than in controls, but with no clinical symptoms or signs of ketonaemia. Low-grade ketonaemia after dapagliflozin treatment may also be associated with improved insulin sensitivity.

A Randomized Clinical Trial Evaluating rh-FGF-2/ß-TCP in Periodontal Defects.

Biological mediators have been used to enhance periodontal regeneration. The aim of this prospective randomized controlled study was to evaluate the safety and effectiveness of 3 doses of fibroblast growth factor 2 (FGF-2) when combined with a ß-tricalcium phosphate (ß-TCP) scaffold carrier placed in vertical infrabony periodontal defects in adult patients. In this double-blinded, dose-verification, externally monitored clinical study, 88 patients who required surgical intervention to treat a qualifying infrabony periodontal defect were randomized to 1 of 4 treatment groups-ß-TCP alone (control) and 0.1% recombinant human FGF-2 (rh-FGF-2), 0.3% rh-FGF-2, and 0.4% rh-FGF-2 with ß-TCP-following scaling and root planing of the tooth prior to a surgical appointment. Flap surgery was performed with EDTA conditioning of the root prior to device implantation. There were no statistically significant differences in patient demographics and baseline characteristics among the 4 treatment groups. When a composite outcome of gain in clinical attachment of 1.5 mm was used with a linear bone growth of 2.5 mm, a dose response pattern detected a plateau in the 0.3% and 0.4% rh-FGF-2/ß-TCP groups with significant improvements over control and 0.1% rh-FGF-2/ß-TCP groups. The success rate at 6 mo was 71% in the 2 higher-concentration groups, as compared with 45% in the control and lowest treatment groups. Percentage bone fill in the 2 higher-concentration groups was 75% and 71%, compared with 63% and 61% in the control and lowest treatment group. No increases in specific antibody to rh-FGF-2 were detected, and no serious adverse events related to the products were reported. The results from this multicenter trial demonstrated that the treatment of infrabony vertical periodontal defects can be enhanced with the addition of rh-FGF-2/ß-TCP (ClinicalTrials.gov NCT01728844).

Differences in the HbA1c-lowering efficacy of glucagon-like peptide-1 analogues between Asians and non-Asians: a systematic review and meta-analysis.

AIMS: To compare the HbA1c-lowering efficacy of glucagon-like peptide-1 (GLP-1) analogues between Asians and non-Asians with type 2 diabetes. METHODS: We searched randomized controlled trials from MEDLINE, EMBASE, LILACS, CENTRAL and ClinicalTrials.gov. Studies described in English were included if the treatment duration was 12 weeks or more, information about ethnicity and baseline HbA1c values were available and a GLP-1 analogue was compared with a placebo. For the ethnic comparison, we divided the studies into Asian-dominant studies (≥ 50% Asian participants) and non-Asian-dominant studies (<50% Asian participants). RESULTS: Among the 837 searched studies, 15 trials were included for the meta-analysis. The weighted mean difference of HbA1c with GLP-1 analogues was -1.16% [95% confidence interval (CI) -1.48, -0.85] in the Asian-dominant studies and -0.83% (95% CI -0.97, -0.70) in the non-Asian-dominant studies. The between-group difference was -0.32% (95% CI -0.64, -0.01; p = 0.04). The relative risk (RR) with 95% CIs for achieving the target HbA1c ≤ 7.0% tended to be greater in the Asian-dominant studies [RR 5.7 (3.8, 8.7)] than in the non-Asian-dominant studies [RR 2.8 (2.4, 3.3)]. Body weight changes were similar between the two groups. Hypoglycaemia tended to be more common in Asian-dominant studies (RR 2.8 [2.3, 3.5]) than in non-Asian-dominant studies (RR 1.5 [1.2, 1.8]), but severe hypoglycaemia was very rare in both groups. CONCLUSION: GLP-1 analogues lower HbA1c more in Asian-dominant studies than in non-Asian-dominant studies. Further studies are warranted to explore the potential mechanisms of the ethnic difference.

Differences in the glucose-lowering efficacy of dipeptidyl peptidase-4 inhibitors between Asians and non-Asians: a systematic review and meta-analysis.

AIMS/HYPOTHESIS: The aim of this work was to compare the glucose-lowering efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitors between Asian and non-Asian patients with type 2 diabetes. METHODS: We searched MEDLINE, EMBASE, LILACS, CENTRAL, ClinicalTrials.gov and conference proceedings. Studies were eligible if they were randomised controlled trials with a treatment duration of at least 12 weeks, compared a DPP-4 inhibitor with a placebo as either monotherapy or oral combination therapy, had information on ethnicity and HbA1c values and were published or described in English. A systematic review and meta-analysis with a meta-regression analysis was conducted. RESULTS: Among 809 potentially relevant studies, 55 trials were included. A meta-analysis revealed that DPP-4 inhibitors lowered HbA1c to a greater extent in studies with ≥50% Asian participants (weighted mean difference [WMD] -0.92%; 95% CI -1.03, -0.82) than in studies with <50% Asian participants (WMD -0.65%; 95% CI -0.69, -0.60). The between-group difference was -0.26% (95% CI -0.36, -0.17, p < 0.001). The baseline BMI significantly correlated with the HbA1c-lowering efficacy of DPP-4 inhibitors. The RR of achieving the goal of HbA1c <7.0% (53.0 mmol/mol) was higher in studies with ≥50% Asian participants (3.4 [95% CI 2.6, 4.7] vs 1.9 [95% CI 1.8, 2.0]). The fasting plasma glucose-lowering efficacy was higher with monotherapy in the Asian-dominant studies, but the postprandial glucose-lowering efficacy and changes in body weight were comparable between the two groups. CONCLUSIONS/INTERPRETATION: DPP-4 inhibitors exhibit a better glucose-lowering efficacy in Asians than in other ethnic groups; this requires further investigation to understand the underlying mechanism, particularly in relation to BMI.

Angiogenic biomarkers and healing of living cellular constructs.

The use of intra-oral soft-tissue-engineered devices has demonstrated potential for oral mucosa regeneration. The aim of this study was to investigate the temporal expression of angiogenic biomarkers during wound healing of soft tissue reconstructive procedures comparing living cellular constructs (LCC) with autogenous free gingival grafts. Forty-four human participants bilaterally lacking sufficient zones of attached keratinized gingiva were randomly assigned to soft tissue surgery plus either LCC or autograft. Wound fluid samples were collected at baseline and weeks 1, 2, 3, and 4 post-operatively and analyzed for a panel of angiogenic biomarkers: angiogenin (ANG), angiostatin (ANT), PDGF-BB, VEGF, FGF-2, IL-8, TIMP-1, TIMP-2, GM-CSF, and IP-10. Results demonstrated a significant increase in expression of ANT, PDGF-BB, VEGF, FGF-2, and IL-8 for the LCC group over the autograft group at the early stages of wound repair. Although angiogenic biomarkers were modestly elevated for the LCC group, no clinical correlation with wound healing was found. This human investigation demonstrates that, during early wound-healing events, expression of angiogenic-related biomarkers is up-regulated in sites treated with LCC compared with autogenous free gingival grafts, which may provide a safe and effective alternative for regenerating intra-oral soft tissues (ClinicalTrials.gov number, NCT01134081).

Identification of the duplicated genes for S-adenosyl-l-methionine synthetase (metK1-sp and metK2-sp) in Streptomyces peucetius var. caesius ATCC 27952.

AIMS: To characterize the function of both metK1-sp (sp1190) and metK2-sp (sp1566) in vitro and in vivo, and to study the regulation of doxorubicin production by overexpressing the metK. METHODS AND RESULTS: We cloned two orfs into pET32a(+) respectively, and the formation of S-Adenosyl-l-methionine was clearly observed in the in vitro enzyme assays as functional MetKs. Reverse transcriptase polymerase chain reaction (PCR) analysis indicated that the transcripts for the metK1-sp were repressed as Streptomyces cells entered the decline phase, whereas that of the metK2-sp was induced, suggesting that these MetK proteins may be important for the growth and the regulation of secondary metabolites during the stationary growth phase, whether considered together or separately. Furthermore, we found that the introduction of high-copy-number plasmids containing the metK1-sp and metK2-sp resulted in 2.1- and 1.4-fold greater levels of doxorubicin production than the control transformants containing only the vector, respectively. We also attempted to disrupt the metK-sp and found that doxorubicin production from the metK1-sp-deleted mutant (Streptomyces peucetius/pNN1) was reduced when compared to the parent strain (S. peucetius var. caesius ATCC 27952). CONCLUSIONS: The results of this study indicated that two metK are differentially expressed during cell growth, and that the expressions of the two metK genes are differentially regulated under the same conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptomyces peucetius var. caesius contains two genes, metK1-sp and metK2-sp, which encode functional S-adenosyl-l-methionine synthetase (MetK). The degree of homology (90% identity) found between the two genes shows that metK1-sp and metK2-sp are duplicated genes. Although there is currently no evidence for the relationship of the duplicated metK genes involved in the regulation of doxorubicin production, metK1-sp and metK2-sp may play a role in controlling the stimulation of antibiotic production during secondary metabolism.

Biosynthesis of spectinomycin: heterologous production of spectinomycin and spectinamine in an aminoglycoside-deficient host, Streptomyces venezuelae YJ003.

AIMS: To obtain spectinomycin and spectinamine by heterologous expression into the biosynthetic deoxysugar (desosamine) gene-deleted host Streptomyces venezuelae YJ003. METHODS AND RESULTS: The 17-kb spectinomycin biosynthetic gene cluster from Streptomyces spectabilis ATCC 27741 was heterologously expressed into Streptomyces venezuelae YJ003. Furthermore, the speA, speB and spcS2 encoded in the spectinomycin biosynthetic gene cluster of cosmid pSPC8 were also heterologously characterized to be responsible for the production of spectinamine. CONCLUSIONS: The results of this study indicated that pSPC8 contains all the genes necessary for the biosynthesis of spectinomycin. We also concluded that SpeA, SpeB and SpcS2 are sufficient for the biosynthesis of spectinamine. We also verified that SpeB and SpcS2 show dual character in the biosynthetic pathway of spectinomycin in Streptomyces spectabilis. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the report regarding the expression of a biosynthetic gene cluster that gives rise to the production of aminoglycoside antibiotics in Streptomyces venezuelae YJ003. Therefore, this work may serve as a foundation for further research on spectinomycin biosynthesis and other aminoglycosides.

Expression profiling of radiation-induced genes in radiodermatitis of hairless mice.

BACKGROUND: Radiation induces many cellular events leading to radiodermatitis. OBJECTIVES: The aim of this study was to establish a radiodermatitis model using experimental animals, and to examine the expression profile of radiation-induced genes. METHODS: Hairless mice were irradiated on the dorsal skin; then total RNAs were isolated and microarray hybridizations were performed. RESULTS: Irradiation with a total of 40 Gy (10 Gy day-1 for four consecutive days) provokes radiodermatitis in the hairless mouse. After microarray analysis, 130 genes that showed upregulation by radiation were selected and organized into four different clusters, depending on the time-kinetic pattern. Classification of these genes into several functional categories revealed that various biological processes were globally affected by radiation. These include transcription regulation, signal transduction, cell communication, cell death regulation and metabolism. CONCLUSIONS: These results demonstrate the complexity of the transcriptional profile of the radiation response, providing important clues on which to base further investigations of the molecular events underlying radiodermatitis.

Investigation of jewelry powders radiating far-infrared rays and the biological effects on human skin.

Far-infrared rays have certain kinds of effects on the human body, especially on skin, blood circulation, and skin cell vitalizing. Some jewelry powders radiate far-infrared rays. Jade has powerful far-infrared ray radiation, and tourmaline has pyroelectric and piezoelectric properties and radiated far-infrared rays. The jewelry powders (fine powdered jade and tourmaline powders) were screened by far-infrared rays for radiation properties and tested for the effects of far-infrared rays on the human skin by temperature observation using an infrared thermal analyzer.

The Escherichia coli SOS gene sbmC is regulated by H-NS and RpoS during the SOS induction and stationary growth phase.

sbmC, an Escherichia coli gene, belongs to the SOS regulon, whose product is involved in cell susceptibility to microcin B17 and its expression is induced at the onset of the stationary growth phase. In the present work, we have investigated the regulation of sbmC expression during SOS induction and the stationary growth phase using a single-copy sbmC'-'lacZ fusion. The SOS induction of sbmC is profoundly diminished in the hns mutant and less diminished in the rpoS mutant. The strain with hns, rpoS double mutation, showed a similar level of sbmC induction to that of a strain with hns single mutation. Mutation in rpoS or hns causes the repression of the sbmC gene during the stationary growth phase. The sbmC expression in the rpoS mutant strain was approximately twofold lower than that in the hns mutant and the rpoS hns double mutant showed a similar level of sbmC expression to mutants deficient in rpoS alone. Interestingly, the sbmC'-'lacZ expression in the exponential growth phase was not derepressed in the hns mutant background. Transformation of hns and rpoS mutants with plasmids carrying histone-like nucleoid protein (H-NS) and RpoS effectively restored the sbmC expression to the wild-type level, respectively. The gel mobility shift assay showed that purified H-NS protein directly bound with a high affinity to a DNA fragment carrying the sbmC promoter region. These findings demonstrate that H-NS regulates the sbmC expression via H-NS's direct binding to the promoter region. In conclusion, our data suggest that H-NS and RpoS regulate a stationary phase-inducible sbmC gene in E. coli.

Dithiothreitol induces the sacrificial antioxidant property of human serum albumin in a metal-catalyzed oxidation and gamma-irradiation system.

The species *OH or H2O2 are produced by both metal-catalyzed oxidation (MCO) of reducing equivalents and gamma-irradiation. Intact or Cys-34-modified human serum albumin (HSA) was significantly degraded in the MCO system containing dithiothreitol (DTT) as electron donor, but as long as it lasted, HSA prohibited *OH or H2O2 from initiating molecular damage of DNA. However, in the GSH and ascorbate (nonthiol) MCO system, HSA was not sacrificially degraded, and indeed accelerated the formation of DNA strand breaks. In the y-irradiation system producing *OH from H2O, only DTT attenuated the generation of DNA strand breaks by HSA. It did not degrade more H2O2 in the presence of reduced GSH (thiol-linked peroxidase) than in its absence. Therefore it would seem that in an MCO system, the antioxidant activity of HSA depends on the effectiveness of reducing equivalents to induce exposure of a functional group scavenging the *OH or H2O2 species, by reduction of its disulfide-bonds. In the presence of DTT, disulfide bonds in HSA were quantitatively reduced to cysteinyl residues but not significantly reduced by ascorbate or GSH. In conclusion, the antioxidant activity of HSA in the D

An efficient cell-free protein synthesis system using periplasmic phosphatase-removed S30 extract.

An efficient cell-free translation system was developed by removal of phosphatase localized in the periplasmic space, which hampers the translation reaction by hydrolyzing ATP. S30 extract was prepared from the spheroplast of Escherichia coli, and as much as 40% of ATP-hydrolysis activity of phosphatases could be easily removed by the spheroplast formation. The reaction period of translation using phosphatase-removed S30 extract could be prolonged and protein synthesis was enhanced by more than 30%.

2-Mercaptoethylamine, radioprotector, inhibits the induction of the oxidative stress-inducible (soi) gene by paraquat in Escherichia coli.

To demonstrate the superoxide radical (.O(2)(-)) -scavenging activity of 2-mercaptoethylamine (MEA), we investigated the induction of the oxidative stress-inducible (soi) gene fused lacZ gene (soi-28:: lacZ) by the use of paraquat as a source of.O(2)(-). When MEA or cysteine was added to the cultures before paraquat treatment, soi gene induction by paraquat was significantly inhibited. However, a high quantity of ascorbic acid (5 mm) inhibited soi gene induction by paraquat far less than MEA or cysteine did. The induction of soi gene induction by MEA exhibited a dose-dependent manner in the range of over 0.2 mm. The antagonistic molecules on the radioprotective action of MEA, ascorbic acid and cysteine did not counteract MEA action on the inhibition of paraquat-mediated soi gene induction. To clarify that the MEA action on the inhibition of paraquat-mediated soi gene induction may be due, in part, to.O(2)(-)-scavenging activity, we investigated the ability of MEA to inhibit the nitroblue tetrazolium (NBT) reduction mediated by.O(2)(-)generated in the xanthine oxidase/hypoxanthine system in vitro. At concentrations above 1 mm, MEA effectively inhibited the NBT reduction in a concentration-dependent fashion. Our results demonstrated that MEA has an ability to scavenge.O(2)(-), and so protects against.O(2)(-)-mediated damage.

SOS induction of the recA gene by UV-, gamma-irradiation and mitomycin C is mediated by polyamines in Escherichia coli K-12.

Polyamines are involved in a wide range of cellular metabolism. In this study we investigated the effects of polyamines on the SOS induction of the recA gene by exposure to UV-, gamma-irradiation and mitomycin C employing polyamine-deficient mutant and wild type Escherichia. coli strains carrying recA'::'lacZ transcriptional fusion. In the polyamine-deficient mutant, the induction factor of the recA gene by UV-, gamma-irradiation and mitomycin C-treatment are about 3.0-, 2.5- and 4-fold lower, respectively, than those of the wild type. The exogenous addition of polyamines restored the reduced induction of the recA gene to the wild type level. Tri-amine spermidine effectively restored the recA induction to a level similar to the wild type, while being less restored by the di-amine putrescine. The restoration of recA induction by polyamines may be accomplished in a dose- and charge-dependent manner. Our results strongly suggest that polyamines may play an essential role as the SOS inducing mediator following exposure to damaging agents in E. coli and provide important information that tackles an interesting question in how cells respond to chemical and physical stresses.

The expression of Escherichia coli SOS genes recA and uvrA is inducible by polyamines.

Polyamines are polycationic compounds that have been implicated in a variety of cellular processes. We first report that the expression of recA and uvrA genes in Escherichia coli is inducible by polyamines. The recA and uvrA genes were effectively inducible by spermine (tetra-amine) and less effectively inducible by spermidine (tri-amine). On the other hand, both genes were not significantly inducible by putrescine (diamine) and divalent cation Mg(2+). The expression of both genes was dependent on the charge of the polyamine in the order of spermine (+4), spermidine (+3), and putrescine (+2). The induction of recA and uvrA genes by polyamines showed a dose-dependent relationship and no synergistic effects. Introduction of gyrA mutation conferring DNA relaxation increased the basal expression of recA gene about 2.5-fold compared to the wild type, but did not significantly affect the polyamine-dependent induction ratios of the recA gene. The basal and the polyamine-dependent expression of uvrA gene are not dependent on gyrA mutation. These results suggest that the polyamine-dependent expression of recA and uvrA genes may be regulated in a different way. Our results indicated that polyamines are involved in the SOS induction of recA and uvrA genes at transcriptional levels in E. coli.

The damage-inducible (din) genes of Escherichia coli are induced by various genotoxins in a different way.

The SOS response of Escherichia coli strains carrying the lacZ gene fused to the polB (dinA), dinB or dinD gene were investigated after treatment with several chemical agents and gamma-radiation. The induction levels of polB::lacZ reached levels between 4.0- and 9.0-fold 120 min after treatment with nalidixic acid, H2O2 or ethanol. Pentachlorophenol did not significantly induce any din genes. gamma-Irradiation is not an inducer of polB and ethanol failed to induce dinB::lacZ and dinD::lacZ. Following irradiation with a dose of 10 Gy the responses of dinB and dinD were induced about 2.5-3.0-fold above non-irradiated dinB and dinD. We found that the responses of din::lacZ fusion genes to these genotoxins are induced in a dose-dependent manner. The polB gene showed antagonistic responses to the simultaneous treatment of nalidixic acid and H2O2 or nalidixic acid and ethanol. In addition, dinB and dinD in the presence of both nalidixic acid and H2O2 at the same time showed no synergistic responses.

Identification of genetic factors altering the SOS induction of DNA damage-inducible yebG gene in Escherichia coli.

The yebG gene of Escherichia coli is a novel SOS regulon gene, but details of its regulation mechanism and biological function are not yet known. To characterize the regulation of yebG gene as a SOS gene, we identified the genetic factors affecting the SOS induction of yebG gene using yebG-lacZ operon fusion plasmid. We found that the SOS induction of yebG occurs as the cells enter into the stationary growth phase, but its induction is not observed in LB medium in the presence of 1% glucose. A stationary phase SOS induction of the yebG gene does not require the global regulator of stationary phase-specific genes, rpoS, or gyrA functions, but requires cya encoding the adenylate cyclase and hns encoding the histone-like protein H-NS functions. Our results demonstrated that the induction of a DNA damage-inducible yebG gene of E. coli is dependent on cyclic AMP and H-NS.

The SOS induction of umu'-'lacZ fusion gene by oxidative damage is influenced by polyamines in Escherichia coli.

We report that polyamines have an effect on the SOS response of the umu operon in polyamine-deficient mutant and wild-type Escherichia coli strains carrying the umu'-'lacZ fusion. H2O2 effectively induces umu'-'lacZ in the wild type, but not significantly in the mutant strain. Exogenous polyamines did not restore the umu induction in the mutant to the wild-type level. In logarithmically growing cells, the basal expression of umu gene in the mutant is about five times higher than that of the wild type. The addition of polyamines to the growth medium markedly reduces the basal expression to the wild-type level. This reduction is due not to growth rate but to the polyamine itself. Our results suggest that polyamines are essentially involved in the SOS induction of the umu operon in E. coli.