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BACKGROUND: Corrected QT-interval (QTc) prolongation (QTP) is a rare but fatal adverse effect of antipsychotics. Clozapine is the only antipsychotic recommended for treatment of resistant schizophrenia; however, clozapine has been reported to cause QTP. We sought factors predictive of QTP in patients who had antipsychotic polypharmacy involving clozapine. We explored whether the clozapine blood concentration might predict QTP. METHODS: We included 133 patients with schizophrenia spectrum disorder who had antipsychotic polypharmacy involving clozapine. We used the χ2 and nonparametric tests to compare clozapine therapeutic drug monitoring (TDM) values and QTc-prolonged person (QTPP) status. Multivariate regression and mediator models were used to identify risk factors for QTPP status and QTP. RESULTS: In total, 111 patients were prescribed clozapine. The QTPP rates were 31.3% (20) for men and 23.2% (16) for women. Compared with the non-QTPP group, the QTPP group exhibited significantly higher daily dose of all antipsychotics including clozapine, a higher clozapine dose, and elevated clozapine and norclozapine TDM values. Furthermore, such patients were prescribed a greater number of antipsychotics. Multivariate logistic regression revealed that only the clozapine TDM value could be predictive factor for QTPP status (P = 0.018). A clozapine TDM value above the therapeutic range (>600 mg/dL) was associated with a high risk of QTPP status (adjusted odds ratio, 6.5; 95% confidence interval, 1.7-25.2; P = 0.006). The mediator model revealed that the clozapine TDM values completely mediated the association between the clozapine dose and the QTc interval. CONCLUSIONS: The clozapine blood concentration reliably predicts QTP in patients with clozapine use.
Assuntos
Antipsicóticos , Clozapina , Síndrome do QT Longo , Transtornos Psicóticos , Esquizofrenia , Masculino , Humanos , Feminino , Clozapina/uso terapêutico , Antipsicóticos/uso terapêutico , Transtornos Psicóticos/tratamento farmacológico , Transtornos Psicóticos/complicações , Esquizofrenia/tratamento farmacológico , Esquizofrenia/complicações , Síndrome do QT Longo/induzido quimicamenteRESUMO
KEY MESSAGE: PTR2 in Arabidopsis thaliana is negatively regulated by ABI4 and plays a key role in water uptake by seeds, ensuring that imbibed seeds proceed to germination. Peptide transporters (PTRs) transport nitrogen-containing substrates in a proton-dependent manner. Among the six PTRs in Arabidopsis thaliana, the physiological role of the tonoplast-localized, seed embryo abundant PTR2 is unknown. In the present study, a molecular physiological analysis of PTR2 was conducted using ptr2 mutants and PTR2CO complementation lines. Compared with the wild type, the ptr2 mutant showed ca. 6 h delay in testa rupture and consequently endosperm rupture because of 17% lower water content and 10% higher free abscisic acid (ABA) content. Constitutive overexpression of the PTR2 gene under the control of the Cauliflower mosaic virus (CaMV) 35S promoter in ptr2 mutants rescued the mutant phenotypes. After cold stratification, a transient increase in ABA INSENSITIVE4 (ABI4) transcript levels during induction of testa rupture was followed by a similar increase in PTR2 transcript levels, which peaked prior to endosperm rupture. The PTR2 promoter region containing multiple CCAC motifs was recognized by ABI4 in electrophoretic mobility shift assays, and PTR2 expression was repressed by 67% in ABI4 overexpression lines compared with the wild type, suggesting that PTR2 is an immediate downstream target of ABI4. Taken together, the results suggest that ABI4-dependent temporal regulation of PTR2 expression may influence water status during seed germination to promote the post-germinative growth of imbibed seeds.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Transporte Biológico/fisiologia , Germinação/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Sementes/metabolismo , Água/metabolismo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Germinação/genética , Mutação , Fenótipo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismoRESUMO
Genome engineering without leaving foreign DNA behind requires an efficient counter-selectable marker system. Here, we developed a genome engineering method in Bacillus subtilis using a synthetic gene circuit as a counter-selectable marker system. The system contained two repressible promoters (B. subtilis xylA (Pxyl) and spac (Pspac)) and two repressor genes (lacI and xylR). Pxyl-lacI was integrated into the B. subtilis genome with a target gene containing a desired mutation. The xylR and Pspac-chloramphenicol resistant genes (cat) were located on a helper plasmid. In the presence of xylose, repression of XylR by xylose induced LacI expression, the LacIs repressed the Pspac promoter and the cells become chloramphenicol sensitive. Thus, to survive in the presence of chloramphenicol, the cell must delete Pxyl-lacI by recombination between the wild-type and mutated target genes. The recombination leads to mutation of the target gene. The remaining helper plasmid was removed easily under the chloramphenicol absent condition. In this study, we showed base insertion, deletion and point mutation of the B. subtilis genome without leaving any foreign DNA behind. Additionally, we successfully deleted a 2-kb gene (amyE) and a 38-kb operon (ppsABCDE). This method will be useful to construct designer Bacillus strains for various industrial applications.
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Bacillus subtilis/genética , Redes Reguladoras de Genes , Genes Sintéticos , Engenharia Genética/métodos , Bacillus subtilis/efeitos dos fármacos , Sequência de Bases , Resistência ao Cloranfenicol/genética , DNA Bacteriano/genética , Marcadores Genéticos , Genoma Bacteriano , Dados de Sequência Molecular , Mutagênese , Óperon , Plasmídeos/genéticaRESUMO
V-type nerve agents, known as VX, are organophosphate (OP) compounds, and show extremely toxic effects on human and animals by causing cholinergic overstimulation of synapses. The bacterial organophosphorus hydrolase (OPH) has attracted much attention for detoxifying V-type agents through hydrolysis of the P-S bond. However, low catalytic efficiency of OPH has limited the practical use of the enzyme. Here we present rational design of OPH with high catalytic efficiency for a V-type nerve agent. Based on the model structure of the enzyme and substrate docking simulation, we predicted the key residues that appear to enhance the access of the substrate to the active site of the enzyme, and constructed numerous OPH mutants. Of them, double mutant, L271/Y309A, was shown to exhibit a 150-fold higher catalytic efficiency for VX than the wild-type.
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Arildialquilfosfatase/química , Proteínas de Bactérias/química , Substâncias para a Guerra Química/metabolismo , Desenho de Fármacos , Flavobacterium/enzimologia , Compostos Organotiofosforados/metabolismo , Animais , Arildialquilfosfatase/genética , Proteínas de Bactérias/genética , Catálise , Domínio Catalítico , Humanos , Modelos Químicos , Simulação de Acoplamento Molecular , Mutação , Conformação Proteica , Especificidade por SubstratoRESUMO
Although many patients with major depressive disorder (MDD) complain of neurocognitive impairment, the effects of antidepressant medications on neurocognitive functions remain unclear. This study compares neurocognitive effects of tianeptine and escitalopram in MDD. Patients with MDD (N = 164) were randomly assigned in a 1:1 ratio to either tianeptine (37.5 mg/d) or escitalopram (10 mg/d) for 12 weeks. Outcome measures included clinical improvement, subjective cognitive impairment on memory and concentration, the Mini-Mental State Examination, the Continuous Performance Test, the Verbal Learning Test, and the Raven Progressive Matrices, assessed every 4 weeks. After 12 weeks, the tianeptine group showed significant improvement in commission errors (P = 0.002), verbal immediate memory (P < 0.0001), Mini-Mental State Examination (P < 0.0001), delayed memory (P < 0.0001), and reasoning ability (P = 0.0010), whereas the escitalopram group improved in delayed memory and reasoning ability but not in the other measures. Both groups significantly improved in subjective cognitive impairment in memory (P < 0.0001) and concentration (P < 0.0001). Mixed effects model repeated measures analyses revealed that the tianeptine group had a significant improvement in scores of commission errors (F = 6.64, P = 0.011) and verbal immediate memory (F = 4.39, P = 0.038) from baseline to 12 weeks, compared with the escitalopram group, after controlling for age, sex, education years, baseline scores, and changes of depression severity. The treatment of MDD with tianeptine led to more improvements in neurocognitive functions, especially in commission errors and verbal immediate memory, compared with escitalopram, after controlling for changes in depression severity. Both drugs improved subjective cognitive impairment of memory and concentration.
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Citalopram/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/psicologia , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Tiazepinas/uso terapêutico , Antidepressivos Tricíclicos/farmacologia , Antidepressivos Tricíclicos/uso terapêutico , Citalopram/farmacologia , Cognição/efeitos dos fármacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Tiazepinas/farmacologia , Resultado do TratamentoRESUMO
Background/Aims: There is increasing evidence that supplementation with pre- and probiotics appears to have positive effects on irritable bowel syndrome (IBS). The aim of this study was to determine the effects of a new synbiotic formulation on gastrointestinal symptoms in elderly patients with IBS. Methods: Sixty-seven IBS patients aged ≥60 years were randomly assigned to either a placebo group (n=34) or a synbiotic group (n=33). During a 4-week intervention, subjects used a placebo or a synbiotic containing Lactobacillus paracasei DKGF1 and extracts of Opuntia humifusa once a day. Patients were evaluated with the subject global assessment, visual analog scale, and Bristol stool chart. The primary outcome was the overall responder rate and the secondary outcome was the responder rates for abdominal symptom reduction at week 4. Results: Overall, responder rates were significantly higher in the synbiotic group (51.5%) than in the placebo group (23.5%) (p=0.017). Abdominal pain (58.8% vs 81.8%) and psychological well-being (26.4% vs 60.6%) were noticeably improved in the synbiotic group (p=0.038 and p=0.004, respectively). However, there were no significant differences in gas and bloating symptoms (p=0.88 and p=0.88, respectively). In patients with constipation-dominant and diarrhea-dominant IBS (n=16), the synbiotic significantly improved abdominal pain and defecation symptoms (responder rates for the placebo vs the synbiotic: 22.2% vs 85.7%, p=0.04). There were no adverse events in either group. Conclusions: The results indicate that this new synbiotic supplement can potentially relieve abdominal symptoms in elderly IBS patients.
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Síndrome do Intestino Irritável , Lacticaseibacillus paracasei , Opuntia , Simbióticos , Idoso , Humanos , Síndrome do Intestino Irritável/tratamento farmacológico , Resultado do Tratamento , Método Duplo-Cego , Dor Abdominal/etiologiaRESUMO
Extracutaneous mastocytoma is a rare benign tumor composed of mature mast cells and is located in tissues other than the skin. We report the case of a 61-year-old male who was diagnosed with extracutaneous mastocytoma via colonoscopic polypectomy and biopsy. To our knowledge, this was the first case of a solitary extracutaneous mastocytoma of the colon. We reported this case and reviewed the literature.
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Men and women are different, but this difference has not been well reflected in clinical trials and preclinical studies of biomedical science. Gender medicine, which systematically analyzes research results according to sex and gender, has been emphasized to overcome this problem. On the other hand, researchers still have difficulty in applying gender medicine to their research. To perform rigorous gender medicine, using correct terms, a thorough literature review during research planning, appropriate statistical analysis and reporting, and cautious interpretation of the results are necessary. Applying gender medicine will increase the reproducibility of studies, promote discoveries, expand the study relevance, and ultimately improve patient care in both men and women. Here, this study reviewed the practical issues on applying gender medicine to both preclinical and clinical studies in the field of biomedical science.
Assuntos
Pesquisa Biomédica , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Fatores SexuaisRESUMO
Non-viable bacteria, referred to as "paraprobiotics," have attracted attention as potentially safer alternatives to probiotics. The aim of this study was to investigate the efficacy of heat-killed Lactobacillus casei DKGF7 on the symptomatic improvement of irritable bowel syndrome (IBS) in a rat disease model and to elucidate the underlying mechanisms that contribute to the beneficial effects of heat-killed probiotics. Seven male Wistar rats were induced with IBS by restraint stress and administered heat-killed L. casei DKGF7 for four weeks and then compared with seven rats in the control group. Stool consistency measured four weeks after initial treatment was the primary outcome measure. To investigate the mechanism of action of the heat-killed bacteria on IBS, we measured serum corticosterone levels, inflammatory cytokines in colon tissue, and expression of tight junction proteins (TJPs) in the epithelium. The treatment group showed significantly better stool consistency scores than the control group at week 4, as well as at every measured time point (all p values < 0.05). The treatment group showed lower serum corticosterone levels, lower colonic inflammatory cytokine levels, and higher expression of TJPs compared with the control group. Paraprobiotics such as heat-killed L. casei DKGF7 can improve stool consistency in a rat IBS model, which may indicate a potential therapeutic strategy for IBS treatment.
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Síndrome do Intestino Irritável/terapia , Lacticaseibacillus casei , Probióticos/uso terapêutico , Animais , Colo/química , Corticosterona/sangue , Citocinas/análise , Suplementos Nutricionais , Temperatura Alta , Síndrome do Intestino Irritável/induzido quimicamente , Síndrome do Intestino Irritável/metabolismo , Masculino , Polissacarídeos/administração & dosagem , Ratos , Ratos Wistar , Proteínas de Junções Íntimas/análiseRESUMO
The transgalactosylase activity of ß-galactosidase produces galacto-oligosaccharides (GOSs) with prebiotic effects similar to those of major oligosaccharides in human milk. ß-Galactosidases from Bacillus circulans ATCC 31382 are important enzymes in industrial-scale GOS production. Here, we show the high GOS yield of ß-galactosidase II from B. circulans (ß-Gal-II, Lactazyme-B), compared to other commercial enzymes. We also determine the crystal structure of the five conserved domains of ß-Gal-II in an apo-form and complexed with galactose and an acceptor sugar, showing the heterogeneous mode of transgalactosylation by the enzyme. Truncation studies of the five conserved domains reveal that all five domains are essential for enzyme catalysis, while some truncated constructs were still expressed as soluble proteins. Structural comparison of ß-Gal-II with other ß-galactosidase homologues suggests that the GOS linkage preference of the enzyme might be quite different from other enzymes. The structural information on ß-Gal-II might provide molecular insights into the transgalactosylation process of the ß-galactosidases in GOS production.
Assuntos
Lactose , Oligossacarídeos , Bacillus/química , Bacillus/enzimologia , Galactose , Modelos Estruturais , beta-Galactosidase/genéticaRESUMO
BACKGROUND: Microsatellite stable (MSS) BRAF p.V600E mutation colorectal cancer (BRAF-CRC) has a poor prognosis, whereas microsatellite instability (MSI) in BRAF-CRC is associated with a favorable prognosis. Although usually considered a single clinical entity, the MSI BRAF-CRC subtype shows some distinct characteristics in comparison with the MSS BRAF-CRC subtype. METHODS: We conducted a meta-analysis to investigate the influence of clinicopathological features on MSI status in BRAF-CRC. We searched publications up to March 2019 from PubMed, Embase, and the Cochrane Library. The effect of MSI status on outcome parameters was assessed using odds ratios (ORs) with 95% confidence intervals (CIs) and fixed- or random-effects models according to the heterogeneity. RESULTS: After reviewing 2839 reports, 16 eligible studies including 1381 patients with BRAF-CRC met the criteria. The MSI BRAF-CRC subtype was associated with older age, female sex (OR = 1.70; 95% CI = 1.35-2.14; P < 0.00001), proximal tumor location (OR = 5.10; 95% CI = 3.70-7.03; P < 0.00001), early TNM stage (OR = 5.28; 95% CI = 3.93-7.09; P < 0.00001), and poor differentiation (OR = 2.29; 95% CI = 1.60-3.28; P < 0.00001). CONCLUSIONS: MSI was significantly correlated with distinct favorable clinicopathological characteristics in BRAF-CRC. These results suggest that MSI status should be considered as a stratification factor for better management of the BRAF-CRC.
Assuntos
Neoplasias do Colo/genética , Neoplasias Colorretais/genética , Mutação/genética , Proteínas Proto-Oncogênicas B-raf/genética , Adolescente , Adulto , Idoso , Criança , Neoplasias do Colo/diagnóstico , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Prognóstico , Adulto JovemRESUMO
Neurotransmitters are reported to be involved in tumor initiation and progression. This study aimed to elucidate the prognostic value of γ-aminobutyric acid type A receptor δ subunit (GABRD) in colon adenocarcinoma (COAD) using the data from The Cancer Genome Atlas (TCGA) database. The GABRD mRNA expression levels in the COAD and normal tissues were compared using the Wilcoxon rank-sum test. The correlation between clinicopathologic characteristics and GABRD expression was analyzed by Wilcoxon rank-sum test or Kruskal-Wallis test and logistic regression. The prognostic value of GABRD mRNA expression in patients with COAD was determined using the Kaplan-Meier curve and Cox regression analysis. Finally, the molecular mechanisms of GABRD in COAD were predicted by gene set enrichment analysis (GSEA). The COAD tissues exhibited higher GABRD mRNA expression levels than the normal tissues. The logistic regression analysis revealed that GABRD mRNA expression was correlated with TNM stage, N stage, M stage, and microsatellite instability (MSI) status. The Kaplan-Meier survival curve and log-rank test revealed that patients with COAD exhibiting high GABRD mRNA expression were associated with poor overall survival (OS). The multivariate analysis indicated that increased GABRD mRNA expression was an independent prognostic factor and was correlated with a poor OS. The GSEA revealed that GABRD was involved in signaling pathways, including cell adhesion molecules, gap junction, melanogenesis, and mTOR signaling pathway, as well as the signaling pathways associated with basal cell carcinoma or bladder cancer development. In summary, enhanced GABRD mRNA expression may be a potential independent prognostic biomarker for COAD.
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Superoxide dismutase 1 (SOD1) binds copper and zinc ions and is one of three superoxide dismutases responsible for destroying free superoxide radicals in the body. Reactive oxygen species (ROS), including free superoxide radicals, play important roles in colitis. However, the role of SOD1 in oxidative stress under colitis remains unclear. Here, we examined the role of SOD1 in the DSS-induced mouse model of colitis. SOD1 deficiency resulted in severe oxidative stress with body weight loss, epithelial barrier disruption and decreased antioxidant enzyme activities. The levels of neutrophils, monocytes, pro-inflammatory CD11c+ macrophages and CD11b+CD103- dendritic cells (DCs) were increased, while anti-inflammatory CD206+ macrophages and CD11b-CD103+ DCs were decreased, in DSS-treated SOD1-knockout (KO) mice compared to DSS-treated wild-type mice. Furthermore, rescue of SOD activity in SOD1-KO mice by oral gavage of B. amyloliquefaciens SOD (BA SOD) significantly ameliorated enhanced DSS-induced colitis in these mice by suppressing p38-MAPK/NF-κB signaling, which can induce inflammation and apoptosis. Taken together, our results suggest that SOD1-mediated inhibitory responses play a crucial role in limiting the development of DSS-induced colitis, and that BA SOD is a promising candidate for treating colitis.
Assuntos
Colite , Estresse Oxidativo , Superóxido Dismutase-1 , Animais , Colite/induzido quimicamente , Colite/genética , Sulfato de Dextrana , Imunidade , Camundongos , Camundongos Endogâmicos C57BL , Superóxido Dismutase-1/genéticaRESUMO
Colorectal cancer is a significant cause of death since it frequently metastasizes to several organs such as the lung or liver. Tumor development is affected by various factors, including a tumor microenvironment, which may be an essential factor that leads to tumor growth, proliferation, invasion, and metastasis. In the tumor microenvironment, abnormal changes in various growth factors, enzymes, and cytokines can wield a strong influence on cancer. Thrombospondin-4 (THBS4), which is an extracellular matrix protein, also plays essential roles in the tumor microenvironment and mediates angiogenesis by transforming growth factor-ß (TGFß) signaling. Platelet-derived growth factor receptor ß (PDGFRß), which is a receptor tyrosine kinase and is also a downstream signal of TGFß, is associated with invasion and metastasis in colorectal cancer. We identified that PDGFRß and THBS4 are overexpressed in tumor tissues of colorectal cancer patients, and that PDGF-D expression increased after TGFß treatment in the colon cancer cell line DLD-1. TGFß and PDGF-D increased cellular THBS4 protein levels and secretion but did not increase THBS4 mRNA levels. This response was further confirmed by the inositol 1,4,5-triphosphate receptor (IP3R) and stromal interaction molecule 1 (STIM1) blockade as well as the PDGFRß blockade. We propose that the PDGFRß signal leads to a modification of the incomplete form of THBS4 to its complete form through IP3R, STIM1, and Ca2+-signal proteins, which further induces THBS4 secretion. Additionally, we identified that DLD-1 cell-conditioned medium stimulated with PDGF-D promotes adhesion, migration, and proliferation of colon myofibroblast CCD-18co cells, and this effect was intensified in the presence of thrombin. These findings suggest that excessive PDGFRß signaling due to increased TGFß and PDGF-D in colorectal tumors leads to over-secretion of THBS4 and proliferative tumor development.
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The features of herpes zoster share some commonalities with depression, including decreased cellular immunity, a close correlation with nutritional status, and a higher prevalence in the elderly population. We aimed to assess the association between herpes zoster infection and depression in the Korean population.We performed a longitudinal follow-up study of a nationwide sample cohort derived from the Korean National Health Insurance Service database. Individuals diagnosed with depression between 2002 and 2013 (nâ=â58,278) as well as matched controls (nâ=â233,112), with both groups comprising 34.3% male and 65.7% female subjects, were extracted and analyzed for the presence of herpes zoster infection. Depression was diagnosed based on the International Classification of Diseases tenth revision (ICD-10) codes F31-F39, while herpes zoster was diagnosed as ICD-10 B02.The rate of herpes zoster infection was higher in the depressed group (6.8% [3967/58,278]) than in the control group (6.3% [14,689/233,122], Pâ<â.001). The adjusted hazard ratio (HR) for herpes zoster infection was 1.09 (95% CI: 1.05-1.13) in the depressed group (Pâ<â.001). Subgroup analyses revealed that the adjusted HRs for herpes zoster infection were higher only in women younger than 60 years among participants with depression. These HRs were 1.13 (95% CI: 1.02-1.25; Pâ=â.016) in women younger than 40 years and 1.11 (95% CI: 1.04-1.17; Pâ<â.001) in women aged 40-59 years.Depression is a predictor of herpes zoster infection in Korean women younger than 60 years.
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Povo Asiático/estatística & dados numéricos , Transtorno Depressivo/etnologia , Transtorno Depressivo/virologia , Herpes Zoster/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Transtorno Depressivo/diagnóstico , Feminino , Seguimentos , Herpes Zoster/diagnóstico , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prevalência , Modelos de Riscos Proporcionais , República da Coreia/epidemiologia , Fatores Socioeconômicos , Adulto JovemRESUMO
Bacillus subtilis strain natto VK161 was selected for its high production of vitamin K2 Its genome was sequenced and annotated in the Department of Energy-Joint Genome Institute (DOE-JGI) annotation pipeline. It resulted in a chromosome of 4,073,396 bp, which is composed of 4,332 protein-coding genes, 23 rRNA genes, and 77 tRNA genes.
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Rectal involvement by systemic lupus erythematosus (SLE) is quite rare. Approximately 14 cases have been reported worldwide, but only one with ischemic colitis has been reported in Korea. A 17-year-old female patient was hospitalized with abdominal pain and hematochezia. Sigmoidoscopy revealed only a simple rectal ulcer without ischemic colitis. cytomegalovirus and bacterial infections were excluded. A sigmoidoscopic rectal biopsy indicated a rectal invasion by SLE, but the patient showed an acute worsening conditions that did not respond to treatment. This paper reports a case of rectal ulcer that developed in SLE without ischemic colitis with a review of the relevant literature.
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Lúpus Eritematoso Sistêmico/diagnóstico , Doenças Retais/diagnóstico , Abscesso/etiologia , Adolescente , Feminino , Humanos , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Doenças Retais/complicações , Doenças Retais/patologia , Sigmoidoscopia , Esteroides/uso terapêutico , Tomografia Computadorizada por Raios X , Úlcera/complicações , Úlcera/diagnósticoRESUMO
A region suffering from an attack of a nerve agent requires not only a highly sorptive material but also a fast-acting catalyst to decontaminate the lethal chemical present. The product should be capable of high sorptive capacity, selectivity and quick response time to neutralize the long lasting harmful effects of nerve agents. Herein, we have utilized organophosphorus hydrolase (OPH) as a non-toxic bio-catalytic material held in with the supporting matrix of poly-ß-cyclodextrin (PCD) as a novel sorptive reinforced self-decontaminating material against organophosphate intoxication. OPH coated PCD (OPH-PCD) will not only be providing support for holding enzyme but also would be adsorbing methyl paraoxon (MPO) used as a simulant, in a host-guest inclusion complex formation. Sorption trend for PCD revealed preference towards the more hydrophobic MPO against para-nitrophenol (pNP). The results show sorption capacity of 1.26 mg/g of 100 µM MPO with PCD which was 1.7 times higher compared to pNP. The reaction rate with immobilized OPH-PCD was found to be 23% less compared to free enzyme. With the help of OPH-PCD, continuous hydrolysis (100%) of MPO into pNP was observed for a period of 24 h through packed bed reactor with good reproducibility and stability of enzyme. The long-term stability also confirmed its stable nature for the investigation period of 4 days where it maintained activity. Combined with its fast and reactive nature, the resulting self-decontaminating regenerating material provides a promising strategy for the neutralization of nerve agents and preserving the environment.
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Arildialquilfosfatase/química , Substâncias para a Guerra Química/química , Inibidores da Colinesterase/química , Descontaminação/métodos , Enzimas Imobilizadas/química , Inseticidas/química , Paraoxon/análogos & derivados , beta-Ciclodextrinas/química , Adsorção , Biocatálise , Concentração de Íons de Hidrogênio , Paraoxon/químicaRESUMO
The Gram-positive spore-forming bacterium, Bacillus thuringiensis, a member of the Bacillus cereus group, produces chitosanases that catalyze the hydrolysis of chitosan to chitosan-oligosaccharides (COS). Although fungal and bacterial chitosanases belonging to other glycoside hydrolase (GH) families have been characterized in a variety of microorganisms, knowledge on the genetics and phylogeny of the GH-8 chitosanases remains limited. Nine genes encoding chitosanases were cloned from 29 different serovar strains of B. thuringiensis and they were expressed in Escherichia coli. The ORFs of the chitosanases contained 1,359 nucleotides and the protein products had high levels of sequence identity (>96%) to other Bacillus species GH-8 chitosanases. Thin-layer chromatography and HPLC analyses demonstrated that these enzymes hydrolyzed chitosan to a chitosan-trimer and a chitosan-tetramer as major products, and this could be useful in the production of COS. In addition, a simple plate assay was developed, involving a soluble chitosan, for high-throughput screening of chitosanases. This system allowed screening for mutant enzymes with higher enzyme activity generated by error-prone PCR, indicating that it can be used for directed chitosanase evolution.
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Bacillus thuringiensis/enzimologia , Proteínas de Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Proteínas Recombinantes/metabolismo , Sequência de Aminoácidos , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Quitosana/metabolismo , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , DNA Bacteriano/química , DNA Bacteriano/genética , Escherichia coli/genética , Expressão Gênica , Glicosídeo Hidrolases/genética , Dados de Sequência Molecular , Mutagênese , Proteínas Mutantes/metabolismo , Fases de Leitura Aberta , Filogenia , Reação em Cadeia da Polimerase , Proteínas Recombinantes/genética , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
In Bacillus subtilis, large genomic deletions have been carried out for genome reduction, antibiotic overproduction, and heterologous protein overexpression. In view of the eco-friendliness of B. subtilis, it is critical that engineering preserves its food-grade status and avoids leaving foreign DNA in the genome. Existing methods of generating large genomic deletions leave antibiotic resistance markers or display low mutation efficiency. In this study, we introduced a clustered regularly interspaced short palindromic repeat-derived genome engineering technique to develop a highly efficient method of generating large genomic deletions in B. subtilis without any trace of foreign DNA. Using our system, we produced 38 kb plipastatin-synthesizing pps operon deletion with 80% efficiency. The significant increase in mutation efficiency was due to plasmids-delivered Streptococcus pyogenes-originated SpCas9, target-specific sgRNA and a donor DNA template, which produces SpCas9/sgRNA endonuclease complex continuously for attacking target chromosome until the mutagenic repair occurs. Our system produced single-gene deletion in spo0A (â¼100%), point mutation (â¼68%) and GFP gene insertion (â¼97%) in sigE and demonstrated its broad applicability for various types of site-directed mutagenesis in B. subtilis.