Co-Immobilization of ADH and GDH on Metal-Organic-Framework: An Effective Biocatalyst for Asymmetric Reduction of Ketones.

Chiral alcohols are not only important building blocks of various bioactive natural compounds and pharmaceuticals, but can serve as synthetic precursors for other valuable organic chemicals, thus the synthesis of these products is of great importance. Bio-catalysis represents one effective way to obtain these molecules, however, the weak stability and high cost of enzymes often hinder its broad application. In this work, we designed a biological nanoreactor by embedding alcohol dehydrogenase (ADH) and glucose dehydrogenase (GDH) in metal-organic-framework ZIF-8. The biocatalyst ADH&GDH@ZIF-8 could be applied to the asymmetric reduction of a series of ketones to give chiral alcohols in high yields (up to 99 %) and with excellent enantioselectivities (>99 %). In addition, the heterogeneous biocatalyst could be recycled and reused at least four times with slight activity decline. Moreover, E. coli containing ADH and GDH was immobilized by ZIF-8 to form biocatalyst E. coli@ZIF-8, which also exhibits good catalytic behaviours. Finally, the chiral alcohols are further converted to marketed drugs (R)-Fendiline, (S)-Rivastigmine and NPS R-568 respectively.

Directed Evolution and Immobilization of Lactobacillus brevis Alcohol Dehydrogenase for Chemo-Enzymatic Synthesis of Rivastigmine.

Rivastigmine is one of the several pharmaceuticals widely prescribed for the treatment of Alzheimer's disease. However, its practical synthesis still faces many issues, such as the involvement of toxic metals and harsh reaction conditions. Herein, we report a chemo-enzymatic synthesis of Rivastigmine. The key chiral intermediate was synthesized by an engineered alcohol dehydrogenase from Lactobacillus brevis (LbADH). A semi-rational approach was employed to improve its catalytic activity and thermal stability. Several LbADH variants were obtained with a remarkable increase in activity and melting temperature. Exploration of the substrate scope of these variants demonstrated improved activities toward various ketones, especially acetophenone analogs. To further recycle and reuse the biocatalyst, one LbADH variant and glucose dehydrogenase were co-immobilized on nanoparticles. By integrating enzymatic and chemical steps, Rivastigmine was successfully synthesized with an overall yield of 66 %. This study offers an efficient chemo-enzymatic route for Rivastigmine and provides several efficient LbADH variants with a broad range of potential applications.

Prediction of Foodborne Norovirus Outbreaks in Coastal Areas in China in 2008-2018.

Foodborne norovirus outbreak usually poses high risks in coastal areas in China. Owing to the influence of multiple climatic factors, it demonstrates typical seasonality and the hotspots gradually expanded northwards from 2008 to 2018. However, the complex mechanism of the onset of outbreaks makes accurate prediction difficult. Thus, it is in necessity to construct a predictive model for foodborne norovirus outbreaks in coastal areas based on environmental and geographical variables. A novel predictive nonlinear autoregressive model with exogenous inputs model was developed using 11 years of environmental and foodborne norovirus outbreak data collected from coastal areas in China. Five input variables (temperature, precipitation, elevation, latitude, and longitude) were screened through stepwise regression analysis. The predicted model developed in this study was able to reproduce 88.53% of outbreaks reported to the National Public Health Emergency Event Surveillance System (PHEESS) in the model development and 100% of outbreaks reported in the independent cross-validation since the system was first launched in China. In particular, foodborne norovirus outbreaks might occur when the probability is >0.6. The findings of this study suggest that foodborne norovirus outbreaks could be accurately predicted in coastal areas in China using the developed predictive model on a daily basis. The model output is most sensitive to temperature, followed by precipitation, and locations. The application of this predictive model is promising to improve local hygiene management levels, prevent foodborne norovirus outbreaks, and reduce the disease and economic costs in coastal areas in China.

Covalent Organic Frameworks Based Photoenzymatic Nano-reactor for Asymmetric Dynamic Kinetic Resolution of Secondary Amines.

Bio-catalysis represents a highly efficient and stereoselective method for the synthesis of valuable chiral compounds, however, the poor stability and limited reaction types of free enzymes restrict their wide application in industrial production. In this work, to overcome these problems, a multifunctional photoenzymatic nanoreactor CALB@COF-Ir was developed through the encapsulation of Candida antarctica lipase B (CALB) in a photosensitive covalent organic framework COF-Ir. This bio-nanocluster serves as efficient catalysts in asymmetric dynamic kinetic resolution (DKR) of secondary amines to give a series of chiral amines in high yields (up to 99 %) and enantioselectivities (up to 99 % ee). The well-designed COF-Ir not only acts as safety cover to prevent CALB from deactivation but promotes racemization of secondary amines via photo-induced hydrogen atom transfer (HAT) process. Photoelectric characterization and TDDFT calculation revealed that (ppy)2Ir units in COF-Ir play crucial role in this photocatalytic system which enhance its photo-redox properties through facilitating the separation between photoelectrons (e-) and holes (h+). Furthermore, the heterogeneous photoenzymatic nanoreactor could be recycled for five rounds with slight decline of catalytic reactivity.

Assessing Asymptomatic, Presymptomatic, and Symptomatic Transmission Risk of Severe Acute Respiratory Syndrome Coronavirus 2.

BACKGROUND: The relative contributions of asymptomatic, presymptomatic, and symptomatic transmission of severe acute respiratory syndrome coronavirus 2 have not been clearly measured, although control measures may differ in response to the risk of spread posed by different types of cases. METHODS: We collected detailed information on transmission events and symptom status based on laboratory-confirmed patient data and contact tracing data from 4 provinces and 1 municipality in China. We estimated the variation in risk of transmission over time and the severity of secondary infections by symptomatic status of the infector. RESULTS: There were 393 symptomatic index cases with 3136 close contacts and 185 asymptomatic index cases with 1078 close contacts included in the study. The secondary attack rates among close contacts of symptomatic and asymptomatic index cases were 4.1% (128 of 3136) and 1.1% (12 of 1078), respectively, corresponding to a higher transmission risk from symptomatic cases than from asymptomatic cases (odds ratio, 3.79; 95% confidence interval, 2.06-6.95). Approximately 25% (32 of 128) and 50% (6 of 12) of the infected close contacts were asymptomatic from symptomatic and asymptomatic index cases, respectively, while more than one third (38%) of the infections in the close contacts of symptomatic cases were attributable to exposure to the index cases before symptom onset. CONCLUSIONS: Asymptomatic and presymptomatic transmissions play an important role in spreading infection, although asymptomatic cases pose a lower risk of transmission than symptomatic cases. Early case detection and effective test-and-trace measures are important to reduce transmission.

Neutrophil to high-density lipoprotein ratio has a superior prognostic value in elderly patients with acute myocardial infarction: a comparison study.

BACKGROUND: The importance of the lipid-related biomarkers has been implicated in the pathological process and prognosis of acute myocardial infarction (AMI). Our work was conducted to discuss and compare the predictive ability of the neutrophil to high-density lipoprotein cholesterol (HDL-C) ratio (NHR) with other existing prognostic indices, for instance, the monocyte to HDL-C ratio (MHR) and the low-density lipoprotein cholesterol (LDL-C) to HDL-C ratio (LDL-C/HDL-C) in elderly patients with AMI. METHODS: Our population was 528 consecutive elderly AMI patients (65-85 years) who were enrolled from Tongji Hospital and grouped according to the cutoff points which were depicted by the receiver operating characteristic (ROC). The Kaplan-Meier curves were plotted with the survival data from the follow-up to investigate the difference between cutoff point-determined groups. Moreover, we assessed the impact of NHR, MHR, LDL-C/HDL-C on the long-term mortality and recurrent myocardial infarction (RMI) with Cox proportional hazard models. RESULTS: Mean duration of follow-up was 673.85 ± 14.32 days (median 679.50 days). According to ROC curve analysis, NHR ≥ 5.74, MHR ≥ 0.67, LDL-C/HDL-C ≥ 3.57 were regarded as high-risk groups. Kaplan-Meier analysis resulted that the high-NHR, high-MHR and high-LDL-C/HDL-C groups presented higher mortality and RMI rate than the corresponding low-risk groups in predicting the long-term clinical outcomes (log-rank test: all P < 0.050). In multivariate analysis, compared with MHR and LDL-C/HDL-C, only NHR was still recognized as a latent predictor for long-term mortality (harzard ratio [HR]: 1.96, 95% confidence interval [CI]: 1.02 to 3.75, P = 0.044) and long-term RMI (HR: 2.23, 95% CI: 1.04 to 4.79, P = 0.040). Furthermore, the positive correlation between NHR and Gensini score (r = 0.15, P < 0.001) indicated that NHR was relevant to the severity of coronary artery to some extent. CONCLUSIONS: NHR, a novel laboratory marker, might be a predictor of the long-term clinical outcomes of elderly patients with AMI, which was superior to MHR and LDL-C/HDL-C.

Association between fetuin-A and prognosis of CAD: A systematic review and meta-analysis.

BACKGROUND: Fetuin-A is an anti-inflammation and anti-calcification factor involved in the course of coronary artery disease (CAD). But the association between serum fetuin-A level and the prognosis of CAD patients was still controversial. To clarify the association between serum fetuin-A level and the prognosis of CAD patients, we conducted the present meta-analysis. METHODS: The included studies should be potentially relevant prospective studies published in English language before January 2019. The target population of the present meta-analysis was restricted to patients with CAD. The results of studies must report hazard ratio (HR) or Kaplan-Meier survival curve for all-cause mortality or incidence of secondary cardiovascular disease (CVD) events. The pooled HRs were analysed by the method of meta-analysis. RESULTS: A total of four prospective studies, including 4256 participants with CAD disease, were chosen to be included. The pooled HR for all-cause mortality was 0.57 (95% CI: 0.37-0.87), showing a statistically significant association between high serum fetuin-A level and low all-cause mortality in CAD patients. For the incidence of secondary CVD events, the pooled HR was 0.86 (95% CI: 0.60-1.23), indicating no statistically significant association between serum fetuin-A level and incidence of secondary CVD events in CAD patients. CONCLUSION: High serum fetuin-A level associated with lower all-cause mortality in patients with CAD. No association between serum fetuin-A level and incidence of secondary CVD events was found in patients with CAD.

In situ ionic liquid dispersive liquid-liquid microextraction combined with ultra high performance liquid chromatography for determination of neonicotinoid insecticides in honey samples.

An efficient in situ ionic liquid dispersive liquid-liquid microextraction followed by ultra-performance liquid chromatography was developed to determine four neonicotinoid insecticides in wild and commercial honey samples. In this method, a hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, formed by in situ reaction between potassium hexafluorophosphate and 1-butyl-3-methylimidazolium bromide in sample solution, was used as the extraction solvent. In comparison with the traditional dispersive liquid-liquid microextraction method, the developed method required no dispersive solvent. To achieve high extraction efficiency and enrichment factor, the effects of various experimental parameters were studied in detail. Under the optimized conditions, the limits of detection and quantification were in the ranges of 0.30-0.62 and 1.20-2.50 µg/L, respectively. The method showed high enrichment factors (74-115) with the recoveries between 81.0 and 103.4%. The proposed method was finally applied to different wild and commercial honey samples.

The changing epidemiology of bacillary dysentery and characteristics of antimicrobial resistance of Shigella isolated in China from 2004-2014.

BACKGROUND: Bacillary dysentery caused by bacteria of the genus Shigella is a significant public health problem in developing countries such as China. The objective of this study was to analyze the epidemiological pattern of bacillary dysentery, the diversity of the causative agent, and the antimicrobial resistance patterns of Shigella spp. for the purpose of determining the most effective allocation of resources and prioritization of interventions. METHODS: Surveillance data were acquired from the National Infectious Disease Information Reporting System (2004-2014) and from the sentinel hospital-based surveillance system (2005-2014). We analyzed the spatial and temporal distribution of bacillary dysentery, age and sex distribution, species diversity, and antimicrobial resistance patterns of Shigella spp. RESULTS: The surveillance registry included over 3 million probable cases of bacillary dysentery during the period 2004-2014. The annual incidence rate of bacillary dysentery decreased from 38.03 cases per 100,000 person-years in 2004 to 11.24 cases per 100,000 person-years in 2014. The case-fatality rate decreased from 0.028% in 2004 to 0.003% in 2014. Children aged <1 year and 1-4 years were most affected, with higher incidence rates (228.59 cases per 100,000 person-years and 92.58 cases per 100,000 person-years respectively). The annual epidemic season occurred between June and September. A higher incidence rate of bacillary dysentery was found in the Northwest region, Beijing and Tianjin during the study period. Shigella flexneri was the most prevalent species that caused bacillary dysentery in China (63.86%), followed by Shigella sonnei (34.89%). Shigella isolates were highly resistant to nalidixic acid (89.13%), ampicillin (88.90%), tetracycline (88.43%), and sulfamethoxazole (82.92%). During the study period, isolates resistant to ciprofloxacin and cefotaxime increased from 8.53 and 7.87% in 2005 to 44.65 and 29.94% in 2014, respectively. CONCLUSIONS: The incidence rate of bacillary dysentery has undergone an obvious decrease from 2004 to 2014. Priority interventions should be delivered to populations in northwest China and to individuals aged <5 years. Antimicrobial resistance of Shigella is a serious public health problem and it is important to consider the susceptibility profile of isolates before determining treatment.

[Apoptosis induced by transferring cytosine deaminase suicide gene into kinds of cancer cells with novel polyamidoamine dendrimers].

This study demonstrates efficacy of a novel polyamidoamine dendrimers(PAMAM dendrimers) with pentaerythritol derivatives as the core(G5 PD dendrimer) in deliver of the cytosine deaminase(CD) gene and EGFP gene fusion plasmid into different tumor cell lines to induce apoptosis. The physical and chemical properties of G5 PD dendrimers in terms of DNA complexation, particulate properties and transfection efficiencies were investigated and compared with commercial gene vectors PEI 25 k Da. The optimum ratio of G5 PD dendrimer complexed with plasmid DNA was 0.2∶1, and the particle size of the complex was(100 ± 5) nm. Compared with the commercial gene carriers PEI, G5 PD dendrimer exhibited a higher transfection efficiency at the weight ratio of 1∶1 in three different cell lines, given the fact that PEI are different from PAMAM dendrimers in terms of molecular structure. Furthermore, the cytotoxicity assays of the cell lines transfected with G5 PD dendrimer/p CD-EGFP-N1 followed by exposure to various concentrations of 5-fluorocytosine(5-FC) also showed that the transfected cell lines could generate a very low amount of 5-FC to 5-fluorouracil(5-FU) in a short period of time, which indicating the high expression level of CD gene in the cell line. These results indicate that the CD/5FC system of G5 PD dendrimer has an excellent efficacy in gene delivery.

Serotypes, seasonal trends, and antibiotic resistance of non-typhoidal Salmonella from human patients in Guangdong Province, China, 2009-2012.

BACKGROUND: Non-typhoidal Salmonella is a common cause of infectious diarrhea in humans. Antimicrobial-resistant Salmonella has become a global concern. METHODS: Using laboratory-based surveillance system for Salmonella from September 2009 to December 2012 in Guangdong Province of China. The clinical information and samples of diarrhea patients were collected, according to the surveillance case definition. The lab tests were followed by standardized protocols, including sample isolation, isolates confirmation, serotyping, and antimicrobial susceptibility testing (AST). RESULTS: A total of 1,826 Salmonella isolates were identified from40,572 patients in 28 hospitals in11 prefectures. The isolates ratio was highest in autumn (38.8%, 708/1826) and lowest in winter (6.4%, 117/1826). Children aged <5 years were the group most affected by Salmonella in Guangdong Province accounting for 73% (1,329/1,826), of whom the infants (<1 year) were 81.5% (1084/1329) especially. A total of 108 serotypes were identified among the isolates. S. Typhimurium represented the most common serotype followed by serotype 4,5,12:i:-. S. Typhimurium was also the common serotype followed by S. Enteritidis among infants and children aged 1-3 years old. However, S. Enteritidis became the common serotype followed by S. Typhimurium among children aged 3-5 and >5 years. Resistance to at least one antimicrobial was found in 72% (1321/1,826) of the isolates. Resistance to at least three antimicrobials was found in 46% (850/1,826) of the isolates. Resistance to all 12 antimicrobials screened was observed in 8 isolates (0.44%, 8/1,826). The resistant prevalence to quinolones including nalidixic acid and ciprofloxacin was 61.9% (1131/1826), of which ciprofloxacin resistance rate was 8.05% (147/1826). The prevalence resistance to all three cephalosporin antimicrobials (cefepime, cefotaxime, and caftazidime) in <5 yr age group was accounted for 90% (89/99). CONCLUSIONS: Additional data and more refined methods can improve future surveillance. The invasive Salmonella isolates should also be included to the antibiotic resistance surveillance for clinical care or public health.

Risk Factors for Vibrio parahaemolyticus Infection in a Southern Coastal Region of China.

OBJECTIVES: The objectives of the study were to identify dietary and medical risk factors for Vibrio parahaemolyticus (VP) infection in the coastal city Shenzhen in China. METHODS: In April-October 2012, we conducted a case-control study in two hospitals in Shenzhen, China. Laboratory-confirmed VP cases (N = 83) were matched on age, sex, and other social factors to healthy controls (N = 249). Subjects were interviewed using a questionnaire on medical history; contact with seawater; clinical symptoms and outcome; travel history over the past week; and dietary history 3 days prior to onset. Laboratory tests were used to culture, serotype, and genotype VP strains. We used logistic regression to calculate the odds ratios for the association of VP infection with potential risk factors. RESULTS: In multivariate analysis, VP infection was associated with having pre-existing chronic disease (adjusted odds ratio [aOR], 6.0; 95% confidence interval [CI], 1.5-23.7), eating undercooked seafood (aOR, 8.0; 95% CI, 1.3-50.4), eating undercooked meat (aOR, 29.1; 95% CI, 3.0-278.2), eating food from a street food vendor (aOR, 7.6; 95% CI, 3.3-17.6), and eating vegetable salad (aOR, 12.1; 95% CI, 5.2-28.2). CONCLUSIONS: Eating raw (undercooked) seafood and meat is an important source of VP infection among the study population. Cross-contamination of VP in other food (e.g., vegetables and undercooked meat) likely plays a more important role. Intervention should be taken to lower the risks of cross-contamination with undercooked seafood/meat, especially targeted at people with low income, transient workers, and people with medical risk factors.

A Novel KIF4A-Related Model for Predicting Immunotherapy Response and Prognosis in Kidney Renal Clear Cell Carcinoma.

BACKGROUND: The efficacy of chemotherapy in treating Kidney Renal Clear Cell Carcinoma (KIRC) is limited, whereas immunotherapy has shown some promising clinical outcomes. In this context, KIF4A is considered a potential therapeutic target for various cancers. Therefore, identifying the mechanism of KIF4A that can predict the prognosis and immunotherapy response of KIRC would be of significant importance. METHODS: Based on the TCGA Pan-Cancer dataset, the prognostic significance of the KIF4A expression across 33 cancer types was analyzed by univariate Cox algorithm. Furthermore, overlapping differentially expressed genes (DEGs1) between the KIF4A high- and lowexpression groups and DEGs2 between the KIRC and normal groups were also analyzed. Machine learning and Cox regression algorithms were performed to obtain biomarkers and construct a prognostic model. Finally, the role of KIF4A in KIRC was analyzed using quantitative real-time PCR, transwell assay, and EdU experiment. RESULTS: Our analysis revealed that KIF4A was significant for the prognosis of 13 cancer types. The highest correlation with KIF4A was found for KICH among the tumour mutation burden (TMB) indicators. Subsequently, a prognostic model developed with UBE2C, OTX1, PPP2R2C, and RFLNA was obtained and verified with the Renal Cell Cancer-EU/FR dataset. There was a positive correlation between risk score and immunotherapy. Furthermore, the experiment results indicated that KIF4A expression was considerably increased in the KIRC group. Besides, the proliferation, migration, and invasion abilities of KIRC tumor cells were significantly weakened after KIF4A was knocked out. CONCLUSION: We identified four KIF4A-related biomarkers that hold potential for prognostic assessment in KIRC. Specifically, early implementation of immunotherapy targeting these biomarkers may yield improved outcomes for patients with KIRC.

Systematic review of human listeriosis in China, 1964-2010.

OBJECTIVES: Listeria is an important foodborne pathogen with severe manifestations and high case-fatality rate. However, listeriosis is not yet a notifiable disease in China, and there is no national monitoring system for cases. We conducted a systematic review to better understand the clinical and epidemiologic features of listeriosis in China. METHODS: Both electronic and manual retrieval systems were used to search Chinese literature for cases and isolates of human listeriosis reported between 1964 and 2010. We recorded and analysed demographic, clinical and laboratory information available for reported cases. RESULTS: A total of 147 clinical cases, 479 Listeria isolates and 82 outbreak-related cases were reported in 28 (90%) provinces in China from January 1964 to December 2010. Of the clinical cases, 45 (31%) were central nervous system infections, 68 (46%) were septicaemia and 34 (23%) were focal infections or gastroenteritis. The overall case-fatality rate was 26% (34/130) among clinical cases with known outcomes and 46% (21/46) among neonatal cases. CONCLUSION: Listeriosis cases occurred in China throughout the study period between 1964 and 2010. Case-fatality was similar to published data from other countries. China should consider requiring notification of listeriosis cases to improve estimates of incidence, identification of risk factors and design of preventive measures.

[Clinical analysis of percutaneous nephrolithotomy for staghorn calculi with different stone branch number].

OBJECTIVE: To investigate the impact of staghorn stone branch number on outcomes of percutaneous nephrolithotomy (PNL). METHODS: From January 2009 to January 2013, the 371 patients with staghorn stones who were referred to our hospital for PNL were considered for this study. All calculi were showed with CT 3-dimentional reconstruction (3-DR) imaging. The computerized database of the patients had been reviewed. Our exclusion criterion was patients with congenital renal anomalies, such as horse-shoe and ectopic kidneys. And borderline stones that branched to one major calyx only were also not included. From 3-DR images, the number of stone branching into minor renal calices was recorded. We made "3" as the branch breakdown between groups. And the patients were divided into four groups. The number of percutaneous tract, operative time, staged PNL, intra-operative blood loss, complications, stone clearance rate, and postoperative hospital day were compared. RESULTS: The 371 patients (386 renal units) underwent PNL successfully, included 144 single-tract PNL, 242 multi-tract PNL, 97 staged PNL. The average operative time was (100 ± 50) minutes; the average intra-operative blood loss was (83 ± 67) ml. The stone clearance rate were 61.7% (3 days) and 79.5% (3 months). The postoperative hospital stay was (6.9 ± 3.4) days. A significantly higher ratio of multi-tract (χ(2) = 212.220, P < 0.01) and staged PNL (χ(2) = 49.679, P < 0.01), longer operative time (F = 4.652, P < 0.01) and postoperative hospital day (F = 2.067, P = 0.043) and lower rate of stone clearance (χ(2) = 10.691 and 47.369, P < 0.05) were found in PNL for calculi with stone branch number ≥ 5. There was no statistically meaningful difference among the 4 groups based on Clavien complication system (P = 0.460). CONCLUSION: The possibility of multi-tract and staged PNL, lower rate of stone clearance and longer postoperative hospital day increase for staghorn calculi with stone branch number more than 5.

Epidemiological Characteristics and Spatiotemporal Distribution Patterns of Human Norovirus Outbreaks in China, 2012-2018.

Objective: To clarify the epidemiological characteristics and spatial distribution patterns of human norovirus outbreaks in China, identify high-risk areas, and provide guidance for epidemic prevention and control. Methods: This study analyzed 964 human norovirus outbreaks involving 50,548 cases in 26 provinces reported from 2012 to 2018. Epidemiological analysis and spatiotemporal scanning analysis were conducted to analyze the distribution of norovirus outbreaks in China. Results: The outbreaks showed typical seasonality, with more outbreaks in winter and fewer in summer, and the total number of infected cases increased over time. Schools, especially middle schools and primary schools, are the most common settings of norovirus outbreaks, with the major transmission route being life contact. More outbreaks occurred in southeast coastal areas in China and showed significant spatial aggregation. The highly clustered areas of norovirus outbreaks have expanded northeast over time. Conclusion: By identifying the epidemiological characteristics and high-risk areas of norovirus outbreaks, this study provides important scientific support for the development of preventive and control measures for norovirus outbreaks, which is conducive to the administrative management of high-risk settings and reduction of disease burden in susceptible areas.

Survey of physician diagnostic and treatment practices for patients with acute diarrhea in Guangdong province, China.

Although international clinical guidelines generally recommend performing bacterial stool culture in patients with acute diarrhea and fever and discourage routine antibiotic prescribing, clinical practice varies. Understanding practice patterns can help health officials assess the sensitivity of laboratory-based enteric infection surveillance systems and the need to improve antibiotic prescribing practices. We surveyed physicians in Guangdong province, China, to measure their practices for patients with acute diarrhea. A standardized questionnaire was used to interview physicians working in hospitals participating in a Salmonella surveillance system in Guangdong, China. The questionnaire asked physicians about their routine practice for patients with diarrhea, including how they managed the last patient they had seen with acute diarrhea. We calculated the odds ratio and 95% confidence interval for factors associated with ordering a stool culture and for prescribing antibiotics. We received surveys from 237 physicians across 22 hospitals in Guangdong. For the last patient with diarrhea whom they had evaluated, 134 (57%) reported ordering a stool culture. The most common reasons for not ordering a stool culture included that it takes too long to receive the result, that the patient is not willing to pay for the test, and that the patient's illness was too mild to warrant testing. Most physicians prescribed at least one medication for the last patient with diarrhea whom they had evaluated. Of the 237 physicians surveyed, 153 (65%) prescribed antibiotics, 135 (57%) probiotics, and 115 (49%), a gastric mucosal protective drug. In conclusion, physicians in Guangdong, China, reported high rates of ordering bacterial stool cultures from patients with diarrhea, possibly associated with their hospital's participation in a special surveillance project. The high rate of antibiotic prescribing suggests that efforts to promote judicious antibiotic use, such as physician education, are needed.

Laboratory-based surveillance of non-typhoidal Salmonella infections in Guangdong Province, China.

Salmonella is one of the most common foodborne pathogens in humans. Laboratory-based surveillance for non-typhoidal Salmonella infection was conducted in Guangdong Province, China to improve understanding about the disease burden and detection of dispersed outbreaks. Salmonella isolated from patients with diarrhea were sent from 16 sentinel hospitals to local public health laboratories for confirmation, serotyping, antimicrobial susceptibility testing, and pulsed-field gel electrophoresis (PFGE). PFGE patterns were analyzed to identify clusters representing potential outbreaks. Between September 2009 and October 2010, 352 (4%) Salmonella isolates were obtained from 9167 stool specimens. Salmonella enterica serotype Typhimurium (45%) and Salmonella enterica serotype Enteritidis (13%) were the most common serotypes, and multidrug resistance was high, especially in Salmonella Typhimurium isolates. PFGE patterns of obtained Salmonella isolates were found to be diverse, but a unique PFGE pattern comprising 53 Salmonella Typhimurium isolates were found to occur almost exclusively in infants. Epidemiologic studies are ongoing to determine whether a common exposure is the source of the Salmonella Typhimurium strain frequently isolated from infants.

[Silencing effect of cell-specific RNA interference plasmid pPSMAe/p-shNS-ploy(A) loaded by transgenic vector Tf-PEG-PEI targeting nucleostemin on prostate cancer cells in vitro].

OBJECTIVE: To explore the transgenic efficiency of non-viral vector Tf-PEG-PEI and the cell specific silencing effect of plasmid pPSMAe/p-shNS-ploy(A) on prostate cancer cells. METHODS: Polyethyleneimine (PEI) was modified by using polyethylene glycol and transferrin to synthesize the non-viral vector Tf-PEG-PEI. NS-specific plasmids pPSMAe/p-shNS-ploy(A) and Tf-PEG-PEI were used to transfect prostate cancer LNCap and PC-3 cells. The changes of cell morphology, proliferation ability and cell cycle were studied after down-regulating the NS gene level. RESULTS: Tf-PEG-PEI was successfully modified. After transfection, the PSMA-expressing LNCaP cells became larger and showed more pseudopodia, having a tendency to differentiate. Their cell proliferation ability was reduced, and the detection of cell cycle showed a decrease of S phase and an increase of G(1) phase after knocking down NS gene. These targets were not changed in non-PSMA-expresing PC-3 cells. CONCLUSIONS: The non-viral vector Tf-PEG-PEI has a high ability to transfer targeted gene into target cells. The cellular specificity of short-hairpin RNA transcription driven by PSMAe/p is confirmed by silencing NS gene. The use of cell specific promoter may be an effective strategy of gene therapy for prostate cancer.

[Expression of PIM-1 in prostate cancer tissue and its relationship with PSA recurrence].

OBJECTIVE: To explore the expression of the PIM-1 protein in prostate cancer tissue and its relationship with PSA recurrence. METHODS: We used the immunohistochemical SP method to detect the expression of the PIM-1 protein in the prostate tissues of 68 cases of prostate cancer (PCa) and 37 cases of benign prostatic hyperplasia (BPH). RESULTS: The positive rate of the PIM-1 protein expression was 67.65% (46/68) in the PCa tissue, significantly higher than 40.54% (15/37) in the BPH tissue (P<0.05). Its positive rates in PCa Gleason scores 6, 7 and 8-10 were 33.33% (7/21), 77.5% (21/28) and 94.74% (18/19), respectively, with significant between-group differences (P<0.05), and those in stages I , II, III and IV of PCa were 47.62%, 53.85%, 73.33% and 94.74%, respectively. Kaplan-Meier analysis of the results of a 36-month follow-up showed the ratios of PIM-1 expression to PSA recurrence and non-recurrence were 10/22 (45.45%) and 36/46 (78.26%), respectively, with statistically significant differences (P<0.05). CONCLUSION: PIM-1 protein expression in PCa tissue is closely related to the Gleason score and clinical stage of PCa and PSA recurrence, which suggests that the PIM-1 gene plays an important role in PCa evolution and progression, and may be an indicator for the prognosis of PCa.