Molecular analysis of MLH1 variants in Chinese sporadic colorectal cancer patients

Single nucleotide polymorphisms (SNPs) in mismatch repair genes, especially in the MLH1 gene, are closely associated with susceptibility to hereditary nonpolyposis colorectal cancer. However, few relevant findings are available regarding the association between sporadic colorectal cancer (SCRC) and SNPs of MLH1 in Chinese patients. Therefore, the present study aimed to describe the pathogenic association between three important MLH1 polymorphisms and SCRC in the Chinese population. Peripheral blood samples from 156 SCRC patients and 311 healthy controls were collected. DNA was purified from peripheral blood, and the V384D, R217C, and I219V polymorphisms were evaluated using high-resolution melting analysis and direct sequencing. The association between the three important MLH1 polymorphisms and clinical pathological features of the SCRC patients was analyzed. In addition, PMS2-MLH1 protein interactions were determined by co-immunoprecipitation (Co-IP) to determine the protein functional alteration induced by these SNPs. Among the three polymorphisms, V384D was significantly associated with the risk of SCRC (OR = 31.36, P < 0.0001). The allele frequencies were 4.81 and 0.16% in the SCRC group. No association was found between SCRC and R217C, or between SCRC and I219V. Moreover, the allele frequency of R217C was significantly higher in the SCRC patients younger than 60 years than in those older than 60 years. Co-IP showed that the MLH1 R217C, V384D, and I219V variants had relative binding abilities with PMS2 of 0.59, 0.70, and 0.80, respectively, compared with the wild-type. These findings suggest that MLH1 V384D could be a promising genetic marker for susceptibility to SCRC.

Epidemiology and Clinical Characteristics of Pediatric Drug-Resistant Tuberculosis in Chongqing, China

To gain insight into the epidemiology of childhood drug resistant tuberculosis (DR-TB) in China that has the second largest burden of TB and the largest number of multidrug resistant (MDR) TB cases in the world, we performed the cross-sectional study to investigate drug resistance of four first-line anti-TB drugs (isoniazid, rifampicin, streptomycin and ethambutol) using Mycobacterium tuberculosis isolates from 196 culture-confirmed pediatric TB cases diagnosed in the Children's Hospital of Chongqing Medical University, China during 2008-2013. Univariate and multivariate logistic regression analyses were performed to assess the associations between patient demographic and clinical characteristics and DR-and MDR-TB, respectively. Twenty-eight percent (56/196) of the study patients exhibited resistance to at least one of the four first-line anti-TB drugs tested. MDR was found in 4.6% (9/196) of the study patients. More than half (5/9, 55.6%) of the MDR cases were from a single county of Chongqing. A significant association was found between being acid-fast bacilli-smear negative and DR-TB (adjusted OR, 2.33; 95% CI, 1.13-4.80) and between having concurrent thoracic-extrathoracic involvement and MDR-TB (adjusted OR, 9.49; 95% CI, 1.05-85.92), respectively. The findings of this study indicate that the rate of DR is high among pediatric TB patients in Chongqing and suggest an urgent need for studies to identify MDR transmission hotspots in Chongqing, thereby contributing to the control DR- and MDR-TB epidemics in China. The study also generates new insight into the pathogenesis of DR and MDR M. tuberculosis strains and highlights the importance of studying childhood TB to the goal of global TB control.

The prevalence, awareness, treatment and control of dyslipidemia among adults in China

OBJECTIVES

To analyze the prevalence, awareness, treatment, control and epidemiological characteristics of dyslipidemia in Chinese adults.

METHODS

In this cross-sectional study, we adopted a multi-stage, stratified sampling method to obtain representative samples of the general population aged >18 years from different urban and rural regions in China. All subjects completed a lifestyle and medical history questionnaire and were examined for risk factors. Dyslipidemia was defined according to criteria of the 2007 Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. Continuous variables were compared using variance analysis. Multivariate logistic regression analysis was performed to explore the risk factors of dyslipidemia.

RESULTS

The prevalence of dyslipidemia was 34.0% overall, and 35.1%, and 26.3% in urban and rural areas, respectively. The prevalence of dyslipidemia was significantly higher in men than women (41.9% vs 32.5%; P < 0.001). Rates of awareness, treatment, and control were 31.0%, 19.5%, and 8.9%, respectively. Increasing age (OR = 1.012; 95% CI:1.010, 1.014), male sex (OR = 1.411; 95% CI:1.318, 1.510), obesity (OR = 1.424; 95% CI:1.345, 1.507), cardiovascular disease (OR = 1.343; 95% CI:1.125, 1.603), diabetes (OR = 1.955; 95% CI:1.751, 2.182), hypertension (OR = 1.481; 95% CI:1.391, 1.577) and hyperuricemia (OR = 2.223; 95% CI:2.060, 2.399) were independent risk factors of dyslipidemia.

CONCLUSION

The prevalence of dyslipidemia among Chinese adults was high but awareness, treatment, and control of dyslipidemia were low. Urban high income earners and rural medium income earners show higher prevalence. Low income earners in urban and rural population have the worst awareness treatment, and control rate. There is an increased need for closely monitoring and controlling high risk factors in the populations including postmenopausal women, unhealthy lifestyle peoples and patients with chronic non-communicable diseases.

Design of a molecular imprinting biosensor with multi-scale roughness for detection across a broad spectrum of biomolecules

The molecular imprinting technique has tremendous applications in artificial enzymes, bioseparation, and sensor devices.

Quantitative real-time detection of carcinoembryonic antigen (CEA) from pancreatic cyst fluid using 3-D surface molecular imprinting

In this study, a real time potentiometric biosensor based on the 3D surface molecular imprinting was developed for CEA detection.

A first-principle study of the effect of OH− doping on the elastic constants and electronic structure of HTB-FeF3

FeF₃ with a hexagonal-tungsten-bronze structure (HTB-FeF₃) belongs to one type of promising cathode material for Li-ion batteries. HTB-FeF_3−x(OH)x (x = 0.083, 0.167, 0.333, 0.667, 0.833) can stably exist in usual growth conditions.

Trends of sputum-smear positive tuberculosis in Zimbabwe: 2008-2011

BACKGROUND

Tuberculosis (TB) has remained one of the major public health problems in Zimbabwe with an estimated incidence rate of 552 per 100,000 persons in 2013. The aim of this study was to describe the trends in acid-fast bacilli (AFB) sputum-smear positive (SSP) TB overall and within subpopulations for the period during 2008-2011 in Zimbabwe. Results of this study will contribute towards the evaluation and implementation of targeted TB control interventions.

METHODS

A cross-sectional study design was used to analyze 40, 110 SSP TB patient records routinely collected during 2008-2011. Incidence trends of SSP TB were described by province, sex, and age group. A Mantel-Haenszel Chi Statistic was calculated to compare each provincial SSP TB notification rate to the national SSP TB notification rate.

RESULTS

SSP TB notification rates were higher in the two main urban provinces, the western provinces and Manicaland. The 25-44 year age group accounted for the largest proportion of notified SSP TB. However, the 55-64 year and 65+ age groups had SSP TB notification rates in 2011 higher than the 2008 value. Finally, the average SSP TB notification rate in males was 23% higher than in females.

CONCLUSION

The findings of this study suggest that TB control has successfully decreased the notification rate of SSP TB in Zimbabwe during 2008-2011. However, the disproportionate distribution of SSP TB among different regions and subpopulations of the country highlights the need for more targeted interventions to accelerate the decline of TB in Zimbabwe.

Increased risk of developing lung cancer in Asian patients carrying the TERT rs2736098 G>A polymorphism: evidence from 3,354 cases and 3,518 controls

BACKGROUND

The association between telomerase reverse transcriptase (TERT) rs2736098 G>A and risk of lung cancer (LC) remains inconclusive. To explore the association more precisely, we performed a comprehensive search and conducted a meta-analysis on all eligible case-control studies involving 3,354 cases and 3,518 controls.

METHODS

The 95% confidence interval (95% CI) and the pooled odds ratio (OR) were calculated using a random or fixed effect model. Publication bias, heterogeneity, and sensitivity analysis were also explored.

RESULTS

All studies were case-control studies on LC in patients of Asian descent, consisting of one Korean study and five Chinese studies. Overall, the variant A allele of TERT rs2736098 G>A was found to significantly increase the risk of LC in all genetic models (GA vs GG: OR =1.13, 95% CI =1.02-1.25, P=0.017; AA vs GG: OR =1.78, 95% CI =1.53-2.07, P<0.001; GA/AA vs GG: OR =1.25, 95% CI =1.14-1.38, P<0.001; AA vs

GA/GG

OR =1.66, 95% CI =1.45-1.92, P<0.001). In the subgroup analysis, significant associations were found in Chinese group and hospital-based studies. Different genotype test methods showed no influence on the final results.

CONCLUSION

Our study identified that TERT rs2736098 G>A polymorphism significantly increased the risk of LC in Asian populations.

Effectiveness of contact investigations for tuberculosis control in Arkansas

Comprehensive assessment of the effectiveness of contact investigations for tuberculosis (TB) control is still lacking. In this study, we use a computational model, calibrated against notification data from Arkansas during the period 2001-2011, that reproduces independent data on key features of TB transmission and epidemiology. The model estimates that the Arkansas contact investigations program has avoided 18.6% (12.1-25.9%) of TB cases and 23.7% (16.4-30.6%) of TB deaths that would have occurred during 2001-2014 if passive diagnosis alone were implemented. If contacts of sputum smear-negative cases had not been included in the program, the percentage reduction would have been remarkably lower. In addition, we predict that achieving national targets for performance indicators of contact investigation programs has strong potential to further reduce TB transmission and burden. However, contact investigations are expected to have limited effectiveness on avoiding reactivation cases of latent infections over the next 60 years.

Effects of coarse chalk dust particles (2.5-10 μm) on respiratory burst and oxidative stress in alveolar macrophages

The main aim of the present study was to examine in vitro responses of rat alveolar macrophages (AMs) exposed to coarse chalk dust particles (particulate matter in the size range 2.5-10 μm, PM(coarse)) by respiratory burst and oxidative stress. Chalk PM(coarse)-induced respiratory burst in AMs was measured by using a luminol-dependent chemiluminescence (CL) method. Also, the cell viability; lactate dehydrogenase (LDH) release; levels of cellular superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), malondialdehyde (MDA), and acid phosphatase (ACP); plasma membrane ATPase; and extracellular nitric oxide (NO) level were determined 4 h following the treatment with the different dosages of chalk PM(coarse). The results showed that chalk PM(coarse) initiated the respiratory burst of AMs as indicated by strong CL, which was inhibited by diphenyleneiodonium chloride and L-N-nitro-L-arginine methyl ester hydrochloride. It suggested that chalk PM(coarse) induced the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in AMs. This hypothesis was confirmed by the fact that chalk PM(coarse) resulted in a significant decrease of intracellular SOD, GSH, ACP, and ATPase levels and a notable increase of intracellular CAT, MDA content, and extracellular NO level, consequently leading to a decrease of the cell viability and a increase of LDH release. It was concluded that AMs exposed to chalk PM(coarse) can suffer from cytotoxicity which may be mediated by generation of excessive ROS/RNS. Graphical Abstract The possible mechanism of coarse chalk particles-induced adverse effects in AMs.

Validation of an RNA cell cycle progression score for predicting death from prostate cancer in a conservatively managed needle biopsy cohort

BACKGROUND

The natural history of prostate cancer is highly variable and difficult to predict accurately. Better markers are needed to guide management and avoid unnecessary treatment. In this study, we validate the prognostic value of a cell cycle progression score (CCP score) independently and in a prespecified linear combination with standard clinical variables, that is, a clinical-cell-cycle-risk (CCR) score.

METHODS

Paraffin sections from 761 men with clinically localized prostate cancer diagnosed by needle biopsy and managed conservatively in the United Kingdom, mostly between 2000 and 2003. The primary end point was prostate cancer death. Clinical variables consisted of centrally reviewed Gleason score, baseline PSA level, age, clinical stage, and extent of disease; these were combined into a single predefined risk assessment (CAPRA) score. Full data were available for 585 men who formed a fully independent validation cohort.

RESULTS

In univariate analysis, the CCP score hazard ratio was 2.08 (95% CI (1.76, 2.46), P<10(-13)) for one unit change of the score. In multivariate analysis including CAPRA, the CCP score hazard ratio was 1.76 (95% CI (1.44, 2.14), P<10(-6)). The predefined CCR score was highly predictive, hazard ratio 2.17 (95% CI (1.83, 2.57), χ(2)=89.0, P<10(-20)) and captured virtually all available prognostic information.

CONCLUSIONS

The CCP score provides significant pretreatment prognostic information that cannot be provided by clinical variables and is useful for determining which patients can be safely managed conservatively, avoiding radical treatment.

Different doses of partial liver irradiation promotes hepatic regeneration in rat

The aim of this study is to investigate whether partial liver irradiation promotes hepatic regeneration in rat. Left-half liver of rat was irradiated to 10 Gy, and the Right-half to 0, 5, 10 and 15 Gy, respectively. Then, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels were evaluated on 0 day, 15-day, 30-day, 45-day and 60-day after liver irradiation. Next, the serum HGF, NF-κB and TGF-β1 levels were also analyzed on 60-day after liver irradiation. Lastly, the cyclinD1 protein expression was appraised by western blots on 60-day after liver irradiation. ALT, AST and ALP levels were reduced compared with that of controls. The serum HGF, NF-κB and TGF-β1 levels, and the cyclinD1 protein expression in liver irradiation group were increased compared with that of controls group. However, hepatic regeneration of higher dose-irradiated cirrhotic liver was triggered a more enhanced regeneration, compared with that of higher doses group. In summary, these results suggest that different doses of partial liver irradiation promotes hepatic regeneration in rat.

The molecular mechanisms of sodium metabisulfite on the expression of K ATP and L-Ca2+ channels in rat hearts

Sodium metabisulfite (SMB) is used as an antioxidant and antimicrobial agent in a variety of drugs and foods. However, there are few reported studies about its side effects. This study is to investigate the SMB effects on the expression of ATP-sensitive K(+) (KATP) and L-type calcium (L-Ca(2+)) channels in rat hearts. The results show that the mRNA and protein levels of the KATP channel subunits Kir6.2 and SUR2A were increased by SMB; on the contrary, SMB at 520 mg/kg significantly decreased the expression of the L-Ca(2+) channel subunits Cav1.2 and Cav1.3. This suggests that SMB can activate the expression of KATP channel by increasing the mRNA and protein levels of Kir6.2 and SUR2A, while it inhibits the expression of L-Ca(2+) channels by decreasing the mRNA and protein levels of Cav1.2 and Cav1.3 in rat hearts. Therefore, the molecular mechanism of the SMB effect on rat hearts might be related to the increased expression of KATP channels and the decreased expression of L-Ca(2+) channels.

Effect of sulfur dioxide inhalation on the expression of KATP and L-Ca(2+) channels in rat hearts

Epidemiological studies have revealed an association between sulfur dioxide (SO2) exposure and cardiovascular diseases. This study is designed to investigate the SO2 effect on the expression of ATP-sensitive K(+) (KATP) channel and L-type calcium (L-Ca(2+)) channel in rat hearts. The results show that the mRNA and protein levels of the KATP channel subunits Kir6.2 and SUR2A of rat hearts in SO2 groups were higher than those in control group. SO2 at 14mg/m(3) significantly decreased the expression of the L-Ca(2+) channel subunits Cav1.2 and Cav1.3. This suggests that SO2 can activate the KATP channels by up-regulating the expression of Kir6.2 and SUR2A, while it inhibits the L-Ca(2+) channels by down-regulating the expression of Cav1.2 and Cav1.3 in rat hearts. The molecular mechanism of SO2-induced negative inotropic effect might be linked to the expression changes of these subunits, which may contribute to the pathogenesis of SO2-associated cardiovascular diseases.

Interaction of oridonin with human serum albumin by isothermal titration calorimetry and spectroscopic techniques

Oridonin has been traditionally and widely used for treatment of various human diseases due to its uniquely biological, pharmacological and physiological functions. In this study, the interaction between oridonin and human serum albumin (HSA) was investigated using isothermal titration calorimetry (ITC), in combination with fluorescence spectroscopy and UV-vis absorption spectroscopy. We found that the hydrogen bond and van der Waals force are the major binding forces in the binding of oridonin to HSA. The binding of oridonin to HSA is driven by favorable enthalpy and unfavorable entropy. Oridonin can quench the fluorescence of HSA through a static quenching mechanism. The binding constant between oridonin and HSA is moderate and the equilibrium fraction of unbound oridonin f(u) > 60%. Binding site I is found to be the primary binding site for oridonin. Additionally, oridonin may induce conformational changes of HSA and affect its biological function as the carrier protein. The results of the current study suggest that oridonin can be stored and transported from the circulatory system to reach its target organ to provide its therapeutic effects. But its side-effect in the clinics cannot be overlook. The study provides an accurate and full basic data for clarifying the binding mechanism of oridonin with HSA and is helpful for understanding its effect on protein function during the blood transportation process and its biological activity in vivo.

Effects of sodium metabisulfite on the expression of BK(Ca), K(ATP), and L-Ca(2+) channels in rat aortas in vivo and in vitro

Sodium metabisulfite (SMB) is most commonly used as the preservative in many food preparations and drugs. So far, few studies about its negative effects were reported. The purpose of this study was to investigate the effect of SMB on the expression of big-conductance Ca(2+)-activated K(+) (BKCa), ATP-sensitive K(+) (KATP), and L-type calcium (L-Ca(2+)) channels in rat aorta in vivo and in vitro. The results showed that the mRNA and protein levels of the BKCa channel subunits α and β1 of aorta in rats were increased by SMB in vivo and in vitro. Similarly, the expression of the KATP channel subunits Kir6.1, Kir6.2, and SUR2B were increased by SMB. However, SMB at the highest concentration significantly decreased the expression of the L-Ca(2+) channel subunits Cav1.2 and Cav1.3. These results suggest that SMB can activate BKCa and KATP channels by increasing the expression of α, β1, and Kir6.1, Kir6.2, SUR2B respectively, while also inhibit L-Ca(2+) channels by decreasing the expression of Cav1.2 and Cav1.3 of aorta in rats. The molecular mechanism of SMB-induced vasorelaxant effect might be related to the expression changes of BKCa, KATP, and L-Ca(2+) channels subunits. Further work is needed to determine the relative contribution of each channel in SMB-mediated vasorelaxant effect.

Investigation of fine chalk dust particles' chemical compositions and toxicities on alveolar macrophages in vitro

The aim of the study is to investigate chemical compositions of fine chalk dust particles (chalk PM2.5) and examine their adverse effects on alveolar macrophages (AMs) in vitro. Morphologies and element concentrations of individual chalk particles were analyzed by using the quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA). The oxidative response of AMs and the potential to generate nitric oxide (NO) by luminol-dependent chemiluminescence (CL) and nitrate reductase method were assessed 4h following the treatment of AMs with differing dosages of fine chalk particles, respectively. Oxidative stress and cytotoxicity elicited by chalk PM2.5 were also examined. The results showed that fine chalk particles were mainly composed of gypsum, calcite, dolomite and a little amount of organic adhesives. Exposure to chalk PM2.5 at 100 μg mL(-1) or 300 μg mL(-1) significantly increased intracellular catalase, malondialdehyde, and NO levels and decreased superoxide dismutase level in AMs, leading to leakage of lactate dehydrogenase (LDH) and reduction of the cell viability. Furthermore, luminol-dependent CL from respiratory burst in AMs was enhanced. It was suggested that chalk PM2.5 could make oxidative damages on AMs and result in cytotoxicity, being likely attributed to excessive reactive oxygen species or reactive nitrogen species induced by mixture of fine gypsum and calcite/dolomite particles.

First-principles investigation on the structural, electronic properties and diffusion barriers of Mg/Al doped NaCoO2as the cathode material of rechargeable sodium batteries

Divalent Mg ion doping in NaCoO₂can significantly decrease the diffusion barriers and enhance the Na ion diffusion rate.

High-quality water-soluble luminescent carbon dots for multicolor patterning, sensors, and bioimaging

A rapid and high-output strategy for the fabrication of polymer-like CDs is developed. The CDs are inexpensive to be synthesized and are useful for versatile applications such as anti-counterfeiting, information encryption, and information storage.