Constructing an Asymmetric Covalent Triazine Framework to Boost the Efficiency and Selectivity of Visible-Light-Driven CO2 Photoreduction.

The photocatalytic reduction of CO2 represents an environmentally friendly and sustainable approach for generating valuable chemicals. In this study, a thiophene-modified highly conjugated asymmetric covalent triazine framework (As-CTF-S) is developed for this purpose. Significantly, single-component intramolecular energy transfer can enhance the photogenerated charge separation, leading to the efficient conversion of CO2 to CO during photocatalysis. As a result, without the need for additional photosensitizers or organic sacrificial agents, As-CTF-S demonstrates the highest photocatalytic ability of 353.2 µmol g-1 and achieves a selectivity of ≈99.95% within a 4 h period under visible light irradiation. This study provides molecular insights into the rational control of charge transfer pathways for high-efficiency CO2 photoreduction using single-component organic semiconductor catalysts.

The Effect of the PhoP/PhoQ System on the Regulation of Multi-Stress Adaptation Induced by Acid Stress in Salmonella Typhimurium.

Acidic stress in beef cattle slaughtering abattoirs can induce the acid adaptation response of in-plant contaminated Salmonella. This may further lead to multiple resistance responses threatening public health. Therefore, the acid, heat, osmotic and antibiotic resistances of Salmonella typhimurium (ATCC14028) were evaluated after a 90 min adaption in a pH = 5.4 "mild acid" Luria-Bertani medium. Differences in such resistances were also determined between the ∆phoP mutant and wild-type Salmonella strains to confirm the contribution of the PhoP/PhoQ system. The transcriptomic differences between the acid-adapted and ∆phoP strain were compared to explore the role of the PhoP/Q two-component system in regulating multi-stress resistance. Acid adaptation was found to increase the viability of Salmonella to lethal acid, heat and hyperosmotic treatments. In particular, acid adaptation significantly increased the resistance of Salmonella typhimurium to Polymyxin B, and such resistance can last for 21 days when the adapted strain was stored in meat extract medium at 4 °C. Transcriptomics analysis revealed 178 up-regulated and 274 down-regulated genes in the ∆phoP strain. The Salmonella infection, cationic antimicrobial peptide (CAMP) resistance, quorum sensing and two-component system pathways were down-regulated, while the bacterial tricarboxylic acid cycle pathways were up-regulated. Transcriptomics and RT-qPCR analyses revealed that the deletion of the phoP gene resulted in the down-regulation of the expression of genes related to lipid A modification and efflux pumps. These changes in the gene expression result in the change in net negative charge and the mobility of the cell membrane, resulting in enhanced CAMP resistance. The confirmation of multiple stress resistance under acid adaptation and the transcriptomic study in the current study may provide valuable information for the control of multiple stress resistance and meat safety.

Study of the transfer of Shiga toxin-producing Escherichia coli during the slaughter of cattle using molecular typing combined with epidemiologic data.

Investigation on the distribution and biological characteristics of Shiga-toxin producing Escherichia coli (STEC) during beef processing is essential for in-plant critical control points and food safety risk assessment. Serogroups and subtypes of stx genes of STEC strains isolated from beef processing lines were first investigated. Identification to cross-contamination among different sampling sites was further conducted by combining multilocus sequence typing (MLST) with the previous distribution and characterization data. The PCR-positive rate for STEC in 435 samples from two slaughter plants in China was 14.3% and the isolation rate for the 62 PCR positive and the entire set of 435 samples were 26% and 3.68% respectively. The existence of serotype O157:H7 (33%) and serogroups O121 (42%) and O26 (21%) as well as the high detection rate of high pathogenic gene stx2a (68%) in these serogroups indicated potential risk to the safety of beef. Traceability analysis showed that hide plays a critical role in cross-contamination between feces, lairage pens and post-washing carcasses from a molecular perspective. Intervening measures revolves around de-hiding should be involved in the in-plant safety control policy according to the tracing analysis.

Gastrointestinal Microenvironment Responsive Nanoencapsulation of Probiotics and Drugs for Synergistic Therapy of Intestinal Diseases.

The gut microbiota are prominent in preserving intestinal environmental homeostasis and managing human health, and their dysbiosis has been directly related to many kinds of intestinal diseases. Probiotics-based therapy appears as a promising approach for the treatment of gut microbiota dysbiosis, while it always suffers from limited bioavailability and therapeutic effect after oral administration. Herein, we presented a facile and safe strategy to treat colitis by nanoencapsulation of probiotics and an anti-inflammatory agent, 5-aminosalicylic acid (5-ASA), within the gastrointestinal microenvironment responsive alginate polysaccharide. Because of acid resistance, the alginate-based coating protected probiotics from the harsh gastric condition. The coating could be disintegrated to release probiotics and 5-ASA upon arriving in the intestinal tract, where the pH is normally higher than 5. In the dextran sulfate sodium-induced colitis mouse model, probiotics recovered their bioactivities and acted together with anti-inflammatory 5-ASA to alleviate colitis by upregulating microbiota richness and diversity, reducing expression of proinflammatory cytokines, and restoring intestinal barriers. This work demonstrated the synergistic therapy of intestinal diseases based on alginate-encapsulated probiotics and a clinical drug, which provided an extensive method to improve the therapeutic effect of oral microecologics.

Circular RNA La-related RNA-binding protein 4 correlates with reduced tumor stage, as well as better prognosis, and promotes chemosensitivity to doxorubicin in breast cancer.

OBJECTIVE: We aimed to evaluate the correlation of circular RNA La-related RNA-binding protein 4 (circ-LARP4) with tumor characteristics and prognosis, and its effect on chemosensitivity in breast cancer. METHODS: Circ-LARP4 from tumor and adjacent tissues of 283 female breast cancer patients underwent resection was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Tumor features, disease-free survival (DFS), and overall survival (OS) were recorded. In vitro, circ-LARP4 in human normal mammary epithelial cells (HMEC) and breast cancer cell lines was detected by RT-qPCR. MCF-7 and MDA-MB-231 cells were transfected with circ-LARP4 overexpression plasmid (as OE-Circ group) and control overexpression plasmid (as OE-Control group). Relative cell viability under different concentrations of doxorubicin was measured. RESULTS: Circ-LARP4 was decreased in tumor tissues than adjacent tissues (P < .001). Tumor circ-LARP4 negatively correlated with tumor size (P = .001), T stage (P = .009), N stage (P = .006), and TNM stage (P < .001), whereas positively correlated with DFS (P = .004) and OS (P < .001). In vitro, circ-LARP4 was decreased MCF-7, BT474, MDA-MB-231, and MDA-MB-468 cell lines than HMEC (all P < .001). Relatively cell viability of MCF-7 cells (at 20 nmol/L [P < .05], 40 nmol/L [P < .01], 80 nmol/L [P < .05] of doxorubicin) and MDA-MB-231 cells (at 120 nmol/L [P < .05], 240 nmol/L [P < .05] of doxorubicin) was decreased in OE-Circ group than OE-Control group. IC50 value of doxorubicin was decreased in OE-Circ group than OE-Control group in MCF-7 and MDA-MB-231 cell lines (both P < .01). CONCLUSION: Circ-LARP4 was a potential prognostic biomarker, which might improve the management of breast cancer.

Urinary biomarkers of phthalates exposure and risks of thyroid cancer and benign nodule.

Phthalates have been reported to affect the function and growth of thyroid. However, there is little data on the effect of phthalates on thyroid oncogenesis. Here we explored the associations between phthalates exposure and the risks of thyroid cancer and benign nodule. We sex-matched 144 thyroid cancer, 138 benign nodule patients and 144 healthy adults from Wuhan, China. Eight phthalate metabolites in spot urine samples were quantified using high-performance liquid chromatography and tandem mass spectrometry. The associations of creatinine-corrected urinary phthalate metabolites with the risks of thyroid cancer and benign nodule were assessed using multivariable logistic regression models. We found that urinary monomethyl phthalate (MMP), mono(2-ethyl-5hydroxyhexyl) phthalate (MEHHP) and mono(2-ethylhexyl) phthalate (MEHP) associated with increased risks of thyroid cancer and nodule, with adjusted odds ratios (ORs) ranging from 1.74 to 4.78 comparing the extreme tertiles, and urinary monobutyl phthalate (MBP) was associated with decreased risks of thyroid cancer and benign nodule (all P for trends < 0.05). Male-specific positive associations of urinary monoethyl phthalate (MEP) with thyroid cancer and nodule as well as urinary mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) with thyroid cancer were also observed. Our results suggest that exposure to certain phthalates may contribute to increased risks of thyroid cancer and benign nodule.

The Cyclopropane Fatty Acid Synthase Mediates Antibiotic Resistance and Gastric Colonization of Helicobacter pylori.

Cyclopropane fatty acids (CFAs) are synthetized by the addition of a methylene group from S-adenosyl-l-methionine across the carbon-carbon double bonds of unsaturated fatty acid chains of membrane phospholipids. This fatty acid cyclopropanation, catalyzed by the CFA synthase (CfaS) enzyme, occurs in many bacteria, including the human pathogen Helicobacter pylori Although the cyclopropane modification was reported to play a key role in the adaptation in response to environmental stress, its role in H. pylori remains unknown. In this study, we showed that H. pylori HP0416 encodes a functional CfaS. The enzyme was demonstrated to be required for acid resistance, antibiotic resistance, intracellular survival and mouse gastric colonization, and cell membrane integrity. Moreover, the tool compound dioctylamine, which acts as a substrate mimic, directly inhibits the CfaS function of H. pylori, resulting into sensitivity to acid stress, increased antibiotic susceptibility, and attenuated abilities to avoid macrophage killing and to colonize mouse stomachs. These results validate CfaS as a promising antibiotic target and provide new potentials for this recognized target in future anti-H. pylori drug discovery efforts.IMPORTANCE The increasing prevalence of multidrug-resistant Helicobacter pylori strains has created an urgent need for alternative therapeutic regimens that complement the current antibiotic treatment strategies for H. pylori eradication; however, this is greatly hampered due to a lack of "druggable" targets. Although the CFAs are present in H. pylori cytoplasmic membranes at high levels, their physiological role has not been established. In this report, deletion of the CFA synthase CfaS was shown to attenuate acid and drug resistance, immune escape, and gastric colonization of H. pylori These findings were validated by inhibition of the CfaS activity with the tool compound dioctylamine. These studies identify this enzyme as an attractive target for further drug discovery efforts against H. pylori.

In Vitro and In Vivo Activities of Zinc Linolenate, a Selective Antibacterial Agent against Helicobacter pylori.

Helicobacter pylori is a major global pathogen, and its infection represents a key factor in the etiology of various gastric diseases, including gastritis, peptic ulcers, and gastric carcinoma. The efficacy of current standard treatment for H. pylori infection including two broad-spectrum antibiotics is compromised by toxicity toward the gut microbiota and the development of drug resistance, which will likely only be resolved through novel and selective antibacterial strategies. Here, we synthesized a small molecule, zinc linolenate (ZnLla), and investigated its therapeutic potential for the treatment of H. pylori infection. ZnLla showed effective antibacterial activity against standard strains and drug-resistant clinical isolates of H. pyloriin vitro with no development of resistance during continuous serial passaging. The mechanisms of ZnLla action against H. pylori involved the disruption of bacterial cell membranes and generation of reactive oxygen species. In mouse models of multidrug-resistant H. pylori infection, ZnLla showed in vivo killing efficacy comparable and superior to the triple therapy approach when use as a monotherapy and a combined therapy with omeprazole, respectively. Moreover, ZnLla treatment induces negligible toxicity against normal tissues and causes minimal effects on both the diversity and composition of the murine gut microbiota. Thus, the high degree of selectivity of ZnLla for H. pylori provides an attractive candidate for novel targeted anti-H. pylori treatment.

Correlation of UGT2B7 Polymorphism with Cardiotoxicity in Breast Cancer Patients Undergoing Epirubicin/Cyclophosphamide-Docetaxel Adjuvant Chemotherapy.

PURPOSE: The present study aimed to investigate correlations between uridine glucuronosyltransferase 2B7 (UGT2B7) -161 single nucleotide polymorphism C to T (C>T) and the occurrence of cardiotoxicity in Chinese breast cancer (BC) patients undergoing epirubicin/cyclophosphamide-docetaxel (EC-D) adjuvant chemotherapy. MATERIALS AND METHODS: 427 BC patients who had underwent surgery were consecutively enrolled in this prospective cohort study. All patients were scheduled to receive EC-D adjuvant chemotherapy regimen, and they were divided into UGT2B7 -161 CC (n=141), UGT2B7 -161 CT (n=196), and UGT2B7 -161 TT (n=90) groups according to their genotypes. Polymerase chain reaction was performed for determination of UGT2B7 -161 genotypes. Cardiotoxicity was defined as an absolute decline in left ventricular ejection fraction (LVEF) of at least 10% points from baseline to a value less than 53%, heart failure, acute coronary artery syndrome, or fatal arrhythmia. RESULTS: LVEF values were lower at cycle (C) 4, C8, 3 months after chemotherapy (M3), M6, M9, and M12 compared to C0 (all p<0.001), in BC patients undergoing EC-D adjuvant chemotherapy. Cardiotoxicity was recorded for 4.2% of the overall population and was lowest in the UGT2B7 -161 TT group (1.1%), compared to UGT2B7 -161 CT (3.1%) and UGT2B7 -161 CC (7.8%) group (p=0.026). Multivariate logistic regression revealed that UGT2B7 -161 T allele could independently predict a low occurrence of cardiotoxicity in BC patients undergoing EC-D adjuvant chemotherapy (p=0.004). CONCLUSION: A UGT2B7 -161 T allele serves as a potential biomarker for predicting a low occurrence of cardiotoxicity in BC patients undergoing EC-D adjuvant chemotherapy.

Characteristics of breast cancer in Central China, literature review and comparison with USA.

INTRODUCTION: This work was to analyze characteristics of breast cancer (BC) in Central China, summarize main characteristics in China and compare with USA. METHODS: BC main characteristics from four hospitals in Central China from 2002 to 2012 were collected and analyzed. All the single and large-scale clinical reports covering at least ten years were selected and summarized to calculate the BC characteristics of China. BC Characteristics in USA were selected based on the database from Surveillance, Epidemiology, and End Results (SEER) Program. RESULTS: Age distribution in Central China was normal with one age peak at 45-49 years, displaying differences from USA and Chinese American with two age peaks. BC characteristics in Central China displayed distinct features from USA and Chinese American, including significant younger onset age, lower proportion of patients with stage I, lymph node negative, small tumor size and ER positive. A total ten long-term and large-scale clinical reports were selected for BC characteristics of Mainland China analysis. A total of 53,571 BC patients were enrolled from 1995 to 2012. The main characteristics of BC in Mainland China were similar as that in Central China, but were significant different from developed regions of China (Hong Kong and Taiwan), USA and Chinese American. CONCLUSIONS: BC characteristics in Central China displayed representative patterns of Mainland China, while showed distinct patterns from Chinese patients in other developed areas and USA.

3D Fast Automatic Segmentation of Kidney Based on Modified AAM and Random Forest.

In this paper, a fully automatic method is proposed to segment the kidney into multiple components: renal cortex, renal column, renal medulla and renal pelvis, in clinical 3D CT abdominal images. The proposed fast automatic segmentation method of kidney consists of two main parts: localization of renal cortex and segmentation of kidney components. In the localization of renal cortex phase, a method which fully combines 3D Generalized Hough Transform (GHT) and 3D Active Appearance Models (AAM) is applied to localize the renal cortex. In the segmentation of kidney components phase, a modified Random Forests (RF) method is proposed to segment the kidney into four components based on the result from localization phase. During the implementation, a multithreading technology is applied to speed up the segmentation process. The proposed method was evaluated on a clinical abdomen CT data set, including 37 contrast-enhanced volume data using leave-one-out strategy. The overall true-positive volume fraction and false-positive volume fraction were 93.15%, 0.37% for renal cortex segmentation; 83.09%, 0.97% for renal column segmentation; 81.92%, 0.55% for renal medulla segmentation; and 80.28%, 0.30% for renal pelvis segmentation, respectively. The average computational time of segmenting kidney into four components took 20 seconds.

A novel application of furazolidone: anti-leukemic activity in acute myeloid leukemia.

Acute myeloid leukemia (AML) is the most common malignant myeloid disorder of progenitor cells in myeloid hematopoiesis and exemplifies a genetically heterogeneous disease. The patients with AML also show a heterogeneous response to therapy. Although all-trans retinoic acid (ATRA) has been successfully introduced to treat acute promyelocytic leukemia (APL), it is rather ineffective in non-APL AML. In our present study, 1200 off-patent marketed drugs and natural compounds that have been approved by the Food and Drug Administration (FDA) were screened for anti-leukemia activity using the retrovirus transduction/transformation assay (RTTA). Furazolidone (FZD) was shown to inhibit bone marrow transformation mediated by several leukemia fusion proteins, including AML1-ETO. Furazolidone has been used in the treatment of certain bacterial and protozoan infections in human and animals for more than sixty years. We investigated the anti-leukemic activity of FZD in a series of AML cells. FZD displayed potent antiproliferative properties at submicromolar concentrations and induced apoptosis in AML cell lines. Importantly, FZD treatment of certain AML cells induced myeloid cell differentiation by morphology and flow cytometry for CD11b expression. Furthermore, FZD treatment resulted in increased stability of tumor suppressor p53 protein in AML cells. Our in vitro results suggest furazolidone as a novel therapeutic strategy in AML patients.

Cloning of a novel lipase gene, lipJ08, from Candida rugosa and expression in Pichia pastoris by codon optimization.

A novel lipase gene, lipJ08, was cloned from Candida rugosa ATCC14830, along with the already reported five lipase genes (lip1-lip5). Nucleotide sequencing indicated that the lipJ08 gene contains a 1650 bp open reading frame (ORF) without introns. The deduced amino acid sequence corresponds to 534 amino acid residues, including a putative signal sequence of 15 amino acid residues. Seventeen of the non-universal serine codons (CTG) of lipJ08 were converted into universal serine codons (TCT) by PCR-based mutagenesis. The native and codon-optimized lipJ08 genes were expressed in Pichia pastoris. The hydrolytic activity of the recombinant LIPJ08 was 4.7 U/ml, whereas the activity of the recombinant wild-type lipase could not be detected.

[Two-step synthesis of the full length Aspergillus niger lipase gene lipA leads to high-level expression in Pichia pastoris].

Aspergillus niger lipases are important biocatalysis widely used in industries for food processing and pharmaceutical preparation. High-level expression recombinants can lead to cost effective lipase large scale production. Full length gene synthesis is an efficient measure to enhance the expression level of the gene. In order to reduce the non-specific binding between oligonucleotides and bases mutation caused by the complicate secondary structure of DNA and excessive PCR amplification, a frequently phenomenon in one-step gene synthesis, we used a two-step method including assembly PCR (A-PCR) and digestion-ligation step to synthesis Aspergillus niger lipase gene lipA. Assisted by DNA2.0 and Gene2Oliga software, we optimized the codon usage and secondary structure of RNA and induced enzyme sites Cla I (237 site) and Pst I (475 site) into the gene. In the first step, fragments F1 (237 bp), F2 (238 bp) and F3 (422 bp) were separately synthesized by assembly PCR. In the second step, fragments F1, F2 and F3 were separately digested by Cla I and Pst I, and then ligated into a full length lipA gene. Two-step method efficiently enhanced successful ratio for full-length gene synthesis and dispersed the risk for gene redesign. The synthesized gene was cloned into pPIC9K vector and transferred into Pichia pastoris. After methanol inducement, the expression level of the codon optimized lipA-syn gene reached 176.0 U/mL, 10.8-fold of the original lipA gene (16.3 U/mL) in Pichia pastoris GS1115. The recombinant offers the possibility for lipase large-scale production.

Chemical probes that competitively and selectively inhibit Stat3 activation.

Signal transducer and activator of transcription (Stat) 3 is an oncogene constitutively activated in many cancer systems where it contributes to carcinogenesis. To develop chemical probes that selectively target Stat3, we virtually screened 920,000 small drug-like compounds by docking each into the peptide-binding pocket of the Stat3 SH2 domain, which consists of three sites--the pY-residue binding site, the +3 residue-binding site and a hydrophobic binding site, which served as a selectivity filter. Three compounds satisfied criteria of interaction analysis, competitively inhibited recombinant Stat3 binding to its immobilized pY-peptide ligand and inhibited IL-6-mediated tyrosine phosphorylation of Stat3. These compounds were used in a similarity screen of 2.47 million compounds, which identified 3 more compounds with similar activities. Examination of the 6 active compounds for the ability to inhibit IFN-gamma-mediated Stat1 phosphorylation revealed that 5 of 6 were selective for Stat3. Molecular modeling of the SH2 domains of Stat3 and Stat1 bound to compound revealed that compound interaction with the hydrophobic binding site was the basis for selectivity. All 5 selective compounds inhibited nuclear-to-cytoplasmic translocation of Stat3, while 3 of 5 compounds induced apoptosis preferentially of breast cancer cell lines with constitutive Stat3 activation. Thus, virtual ligand screening of compound libraries that targeted the Stat3 pY-peptide binding pocket identified for the first time 3 lead compounds that competitively inhibited Stat3 binding to its pY-peptide ligand; these compounds were selective for Stat3 vs. Stat1 and induced apoptosis preferentially of breast cancer cells lines with constitutively activated Stat3.

Identification and functional characterization of a novel splicing mutation in RP gene PRPF31.

A six-generation Chinese family with autosomal dominant retinitis pigmentosa (adRP) was identified and characterized. Genome-wide linkage analysis linked the family to markers D19S601 to D19S605, which span the PRPF31 gene on chromosome 19q13.33-13.43 (RP11) (LOD=5.03). Direct DNA sequence analysis identified a novel splicing mutation (IVS1+1G>T) in affected family members and carriers, but not in unaffected family members and 200 normal controls. The splicing mutation occurs at the splicing donor of intron 1. Real time PCR with lymphoblastoid RNA samples from family members showed that in comparison to normal family members, the splicing mutation reduced the expression level of the PRPF31 mRNA by 57% in symptomatic patients and by 28% in clinically asymptomatic carriers. Our studies identify a novel splicing mutation in PRPF31 associated with adRP and suggest that the penetrance of RP11 mutations may be correlated with the expression level of the PRPF31 mRNA.