Biobutanol production from sugarcane bagasse by Clostridium beijerinckii strains.

Acetone-butanol-ethanol (ABE) fermentation was performed with sugarcane bagasse (SCB) hydrolysate using Clostridium beijerinckii strains. A cost-effective SCB medium was developed with no enzymatic hydrolysis and no supplementation of extra carbon source or expensive nitrogen source. One of the C. beijerinckii strains studied was able to produce butanol with butanol productivity of 1.23 g/L/day with butanol yield of 0.18 g/g of sugars from the developed medium. High utilization rate of both glucose and xylose was observed in SCB medium during ABE fermentation. This study shows that SCB is a promising substrate for cellulosic biobutanol production.

Triiodo-L-Thyronine Promotes the Maturation of Cardiomyocytes Derived From Rat Bone Marrow Mesenchymal Stem Cells.

Bone marrow mesenchymal stem cells (BMMSCs) can differentiate into cardiomyocytes and be used in cardiac tissue engineering for heart regeneration. However, the effective clinical application of cardiomyocytes derived from BMMSCs is limited because of their immature phenotype. The aim of this study was to investigate the potential of triiodo-L-thyronine (T3) to drive cardiomyocytes derived from BMMSCs to a more mature state. BMMSCs were divided into 3 groups: untreated controls, differentiated, and T3 treated. The differentiation potential was evaluated by immunofluorescence microscopy and flow cytometry. Data were represented as the numbers of cells positive for the troponin I (cTnI), α-actinin, GATA4, and the connexin-43 (Cx-43). The mRNA levels of these specific markers of cardiomyocytes were determined by quantitative real-time polymerase chain reaction. The levels of cardiomyocytes markers protein and octamer-binding transcription factor 4 (Oct-4) were determined by Western blot analyses. Our data demonstrate that T3 treatment leads to a significant increase in cells positive for cTnI, GATA4, Cx-43, and α-actinin. The mRNA and protein expression levels of these specific markers of cardiomyocytes were also increased after T3 treatment. At the same time, the protein expression level of Oct-4 was substantially downregulated in T3-treated cells. These results demonstrate that T3 treatment increases the differentiation of BMMSCs induced to cardiomyocytes and promotes their maturation.

Adaptive responses by mouse fetus to a maternal HLE diet by downregulating SREBP1: a microarray- and bio-analytic-based study.

Maternal diet has long been recognized as a significant factor affecting offspring development and health, but the target genes affected by a maternal high-lipid diet are currently unknown. In this study, the gene expression profile of neonatal mouse liver was analyzed using gene chips to identify genes with significant up- or downregulated expression levels due to maternal high-fat diet during gestation. Real-time PCR and Western blotting were used to measure key genes selected using microarray. Serum lipid, glucose, and insulin levels in adult offspring from dams fed with chow or a high-lipid diet were measured using commercial kits. Results indicate that the expression of genes involved in cholesterol and fatty acid synthesis were significantly inhibited, while the expression of genes involved in glycolysis were significantly decreased by maternal high-lipid diet during gestation. SREBP1 might be the key gene regulating genes involved in fatty acid, glucose, and cholesterol metabolism in response to a maternal high-fat diet.

Efficacy and safety of vena cava filters in preventing pulmonary embolism: A systematic review and meta-analysis.

OBJECTIVES: To assess the treatment effectiveness of inferior vena cava filters (IVCF) versus non-IVCF for patients undergoing varies conditions. METHODS: We systematically searched the databases to identify eligible RCTs from their inception up to 9/20/2020. The primary endpoint was pulmonary embolism (PE), while the secondary endpoints included deep-vein thrombosis (DVT), major bleeding, and all-cause mortality. The RRs with 95% CIs were applied as effect estimates for the treatment effectiveness of IVCF versus non-IVCF and calculated by using the random-effects model. RESULTS: 1,137 patients of 5 RCTs were enrolled. There were no significant differences between IVCF and non-IVCF for the risk of PE, major bleeding, and all-cause mortality, while the risk of DVT was significantly increased for patients treated with IVCF. CONCLUSIONS: The use of IVCF did not yield any benefits on PE, major bleeding, and all-cause mortality risk for patients undergoing various conditions, while the risk of DVT was significantly increased for patients treated with IVCF.

Outcomes of catheter-directed thrombolysis versus systemic thrombolysis in the treatment of pulmonary embolism: a meta-analysis.

OBJECTIVE: To evaluate the safety and efficacy of catheter-directed thrombolysis (CDT) versus systemic thrombolysis (ST) in the treatment of pulmonary embolism (PE). METHODS: The Cochrane Library, PubMed, and Embase databases were searched to collect the literature on the comparison of the results of CDT and ST in the treatment of PE from the beginning of their records to May 2020, and meta-analysis was performed by STATA software (version 15.1). Using standardized data-collection forms, the authors screened the studies and independently extracted data, and assessed the quality of the studies using the Newcastle-Ottawa Scale for cohort studies. Cohort studies that examined the following results were included in the current study: in-hospital mortality, all-cause bleeding rate, gastrointestinal bleeding rate, intracranial hemorrhage rate, the incidence of shock, and hospital length of stay. RESULTS: A total of eight articles, with 13,242 participants, involving 3962 participants in the CDT group and 9280 participants in the ST group were included. CDT compared with ST in the treatment of PE can significantly affect in-hospital mortality rate [odds ratio (OR) = 0.41, 95% CI: 0.30-0.56, P < 0.05], all-cause bleeding rate (OR = 1.20, 95% CI: 1.04-1.39, P = 0.012), gastrointestinal bleeding rate (OR = 1.43, 95% CI: 1.13-1.81, P = 0.003), the incidence of shock (OR = 0.46, 95% CI: 0.37-0.57, P < 0.05), and hospital length of stay [standard mean difference (SMD) = 0.16, 95% CI: 0.07-0.25, P < 0.05]. However, there was no significant effect on intracranial hemorrhage rate in patients with PE (OR = 0.70, 95% CI: 0.47-1.03, P = 0.070). CONCLUSIONS: CDT is a viable alternative to ST in the treatment of PE, as it can significantly reduce in-hospital mortality rate, all-cause bleeding rate, gastrointestinal bleeding rate, and incidence of shock. However, CDT may prolong hospital length of stay to a certain extent. Further research is needed to evaluate the safety and efficacy of CDT and ST in the treatment of acute PE and other clinical outcomes.

Dual fluorescence system for flow cytometric analysis of Escherichia coli transcriptional response in multi-species context.

When studying interspecies interactions in a bacterial consortium, it may be desirable to analyze one species' transcriptional response as influenced by the other species. We developed a dual fluorescence system of Escherichia coli for Fluorescence-Activated Cell Sorter (FACS)-based analysis for such a purpose. First, we generated E. coli SCC1 strain, which constitutively expresses green fluorescent protein (GFP), but otherwise showed no observable difference from the parent strain MG1655 with respect to morphology, growth, and FACS-analyzed side- and forward-scatter profiles. Next, to analyze transcriptional response, plasmids carrying promoters of interest fused to a red fluorescent protein (AsRed2) reporter, were introduced into strain SCC1. Quantification of promoter activities of araB, lacZ, fadB and rpoE via AsRed2 reporter verified that the induction levels are similar between MG1655 and SCC1 strains. In mixtures and co-cultures, GFP expression of E. coli SCC1 allowed it to be separated from non-E. coli species by FACS to purity levels of 96.7-100.0%. When a mixture of E. coli SCC1 carrying promoter-AsRed2 fusion and a non-E. coli strain was analyzed by FACS, it enabled (i) distinction of E. coli SCC1 from the non-E. coli strain, (ii) analysis of the E. coli promoter activity via AsRed2 expression and (iii) identification of transcriptional heterogeneity within the E. coli population. Co-cultures of E. coli SCC1 with Klebsiella pneumoniae and/or Enterococcus faecalis analyzed by FACS showed that E. coli fadB and rpoE transcription were differentially influenced by partner species.

Occult mediastinal lymph node metastasis in FDG-PET/CT node-negative lung adenocarcinoma patients: Risk factors and histopathological study.

BACKGROUND: The aim of this study was to investigate predictive factors of occult mediastinal lymph node metastasis (MLNM) in preoperative 18 F-fluorodeoxy-glucose PET/CT node-negative lung adenocarcinoma patients. METHODS: We reviewed the clinical data and PET/CT parameters of 360 consecutive pulmonary adenocarcinoma patients who were scheduled to undergo anatomical pulmonary resection and systemic mediastinal node dissection. The nodal metastasis was pathologically defined and all resected tumors were classified according to the 2011 IASLC/ATS/ERS classification. Univariate and multivariate analysis were conducted to evaluate the associations between clinicopathological variables and MLNM. RESULTS: Of all 360 patients, 54 (15.0%) had pathological N2 diseases. The serum CEA level, nodule type, hilar nodal SUVmax, tumor SUVmax, size, location and histologic subtype were associated with MLNM significantly on univariate analysis. On multivariate analysis, CEA ≥ 5.0 ng/mL (P < 0.001), solid nodule (P = 0.012), tumor SUVmax ≥ 3.7 (P < 0.027), hilar nodal SUVmax ≥ 2.0 (P < 0.001) and centrally located tumor (P = 0.035) were independent risk factors for MLNM. The area under the ROC curve (AUC) for tumor SUVmax and hilar nodal SUVmax in predicting MLNM was 0.764 and 0.730, respectively, and the combined use of five factors yielded a higher AUC of 0.885. CONCLUSION: Increased primary tumor and hilar lymph node SUVmax, solid nodule, centrally located tumor and increased CEA level predicted the increased risk of mediastinal lymph node metastasis. Combined use of these factors improved the diagnostic capacity for predicting N2 disease preoperatively. Invasive mediastinal staging should be considered for patients with these risk factors, even those with a negative mediastinum on PET/CT.

Functions of base selection step in human DNA polymerase alpha.

Recent studies have revealed that the base selection step of DNA polymerases (pol) plays a role in prevention of DNA replication errors. We investigated whether base selection is required for the DNA replication fidelity of pol alpha and genomic stability in human cells. We introduced an Leu864 to Phe substitution (L864F) into human pol alpha and performed an in vitro LacZ alpha forward mutation assay. Our results showed that the overall mutation rate was increased by 180-fold as compared to that of the wild-type. Furthermore, steady state kinetics analyses consistently showed that L864F pol alpha had a decreased discrimination ability between correct and incorrect nucleotide incorporation, as well as between matched and mismatched primer termini. L864F pol alpha also exhibited increased translesion activity over the abasic, etheno-A, O(4)-methyl-T, and O(6)-methyl-G sites. In addition, our steady state kinetics analyses supported the finding of increased translesion activity of L864F pol alpha over O(6)-methyl-G. We also established stable clones transfected with pola1L864F utilizing the human cancer cell line HCT116. Using the HPRT gene as a reporter, the spontaneous mutation rate of pola1L864F cells was determined to be 2.4-fold greater than that of wild-type cells. Mutation assays were also carried out using cells transiently transfected with the wild-type or pola1L864F, and increased mutant frequencies were observed in pola1L864F cells under both spontaneous and methyl methanesulfonate-induced conditions. Together, our results indicate that the base selection step in human pol alpha functions to prevent DNA replication errors and maintain genomic integrity in HCT116 cells.

PCNA mono-ubiquitination and activation of translesion DNA polymerases by DNA polymerase {alpha}.

Translesion DNA synthesis (TLS) involves PCNA mono-ubiquitination and TLS DNA polymerases (pols). Recent evidence has shown that the mono-ubiquitination is induced not only by DNA damage but also by other factors that induce stalling of the DNA replication fork. We studied the effect of spontaneous DNA replication errors on PCNA mono-ubiquitination and TLS induction. In the pol1L868F strain, which expressed an error-prone pol alpha, PCNA was spontaneously mono-ubiquitinated. Pol alpha L868F had a rate-limiting step at the extension from mismatched primer termini. Electron microscopic observation showed the accumulation of a single-stranded region at the DNA replication fork in yeast cells. For pol alpha errors, pol zeta participated in a generation of +1 frameshifts. Furthermore, in the pol1L868F strain, UV-induced mutations were lower than in the wild-type and a pol delta mutant strain (pol3-5DV), and deletion of the RAD30 gene (pol eta) suppressed this defect. These data suggest that nucleotide misincorporation by pol alpha induces exposure of single-stranded DNA, PCNA mono-ubiquitination and activates TLS pols.