Lack of association between polymorphisms of MASP2 and susceptibility to SARS coronavirus infection

<p>Abstract</p> <p>Background</p> <p>The pathogenesis of severe acute respiratory disease syndrome (SARS) is not fully understood. One case-control study has reported an association between susceptibility to SARS and <it>mannan-binding lectin </it>(<it>MBL</it>) in China. As the downstream protein of <it>MBL</it>, variants of the <it>MBL</it>-associated serine protease-2 (<it>MASP2</it>) gene may be associated with SARS coronavirus (SARS-CoV) infection in the same population.</p> <p>Methods</p> <p>Thirty individuals with SARS were chosen for analysis of <it>MASP2 </it>polymorphisms by means of PCR direct sequencing. Tag single nucleotide polymorphisms (tagSNPs) were chosen using pairwise tagging algorithms. The frequencies of four tag SNPs (rs12711521, rs2261695, rs2273346 and rs7548659) were ascertained in 376 SARS patients and 523 control subjects, using the Beckman SNPstream Ultra High Throughput genotyping platform.</p> <p>Results</p> <p>There is no significant association between alleles or genotypes of the <it>MASP2 </it>tagSNP and susceptibility to SARS-CoV in both Beijing and Guangzhou populations. Diplotype (rs2273346 and rs12711521)were analyzed for association with susceptibility to SARS, no statistically significant evidence of association was observed. The Beijing and Guangzhou sample groups were homogeneous regarding demographic and genetic parameters, a joined analysis also showed no statistically significant evidence of association.</p> <p>Conclusion</p> <p>Our data do not suggest a role for <it>MASP2 </it>polymorphisms in SARS susceptibility in northern and southern China.</p

Difference in Feeding Behaviors of Two Invasive Whiteflies on Host Plants with Different Suitability: Implication for Competitive Displacement

In China, Bemisia tabaci Q (commonly known as biotype Q) has rapidly displaced B (commonly known as biotype B) in the past 6 years. The mechanisms underlying such phenomenon have been studied extensively in recent years; however, we have not come to a definitive conclusion yet. In the present study, the differences in host suitability between B and Q whitefly adults to five host plants (cabbage, cotton, cucumber, poinsettia, and tomato) were evaluated based on their respective feeding behaviors using a direct-current electrical penetration graph (DC-EPG) system. Pair-wise comparisons of B. tabaci B and Q feeding on each of the five host plants clearly indicate that Q feeds better than B on tomato, cotton and poinsettia, while B feeds better than Q on cabbage and cucumber. The EPG parameters related to both phloem and non-phloem phases confirm that cabbage and cucumber are best suited to B, while tomato, cotton, and poinsettia are best suited to Q. Our present results support the contention that host suitability and adult feeding behavior contribute to the competitive displacement of biotype B by biotype Q. The discrepancy between field (previous studies) and laboratory results (this study), however, suggests that 1) whitefly displacement is apparently contributed by multiple factors; and 2) factor(s) other than the host plant suitability may play a vital role in dictating the whitefly biotypes in the field

Terahertz spectra of electrolyte solutions under applied electric and magnetic fields

Most biomolecules require an aqueous environment to fully exert their biological activity. However, the rotation mode, vibration mode, and energy associated with the hydrogen bonding network of water are in the terahertz band, resulting in strong absorption. Therefore, it is difficult to detect liquid biological samples using the terahertz technology. Here, a high-transmittance double-layer microfluidic chip was prepared using a cycloolefin copolymer material with high transmittance of terahertz waves. Combined with terahertz time-domain spectroscopy, the terahertz spectral characteristics of deionized water, NaCl, NaCO3, and CH3COONa solutions were studied. The changes in the terahertz transmission intensity of these electrolyte solutions under constant electric and magnetic fields were measured. The results show that the terahertz spectra of different sodium salt solutions with the same concentration of 0.9 mol/L are different. Furthermore, the terahertz absorption coefficients of the different electrolyte solutions gradually decrease with the increase of their residence time under the electric field, which is contrary to the results obtained under the external magnetic field. This study provides a new idea for the detection of sodium salt solution and lays a foundation for the development of THz technology

Original Article Benefit of a 360-degree horizontal turn following premedication with simethicone on image quality during gastroendoscopy: a randomized controlled trial

Abstract: Objectives: To investigate whether a 360-degree horizontal turn after oral premedication with simethicone improves the mucosal visibility during gastroendoscopic examination, and to determine the proper time to turn over the patient. Methods: This study involved 993 patients scheduled for gastroendoscopy. Just before gastroendoscopy，after oral premedication with simethicone, patients were randomly assigned to three groups：in Group A, patients waited for 20 min before gastroendoscopy; in Group B, patients were separately waited for 5/10/15/20 min and were then turned 360 degrees just before gastroendoscopy; in Group C, patients were immediately turned 360 degrees and then separately waited for 5/10/15/20 min before examination. The sum of the gastric mucosal visibility scores (MVS) was calculated after the examination. The MVS and proportion of images with higher visibility scores for the mucosal surface. Lower scores indicate better visibility of the mucosal surface. Results: In Groups B and Groups C, when waiting time more than 10 min had lower mean total MVS than Group A. The MVS of four subgroups of Group B were not different from those of Group C. Conclusion: Oral premedication with simethicone and immediately make a body posture change (turning over 360 degrees) then waiting for 10min can increase the image quality during gastroendoscopy and effectively decrease the premedication time

Rapid spread of tomato yellow leaf curl virus in China is aided differentially by two invasive whiteflies

BACKGROUND: Tomato yellow leaf curl virus (TYLCV) was introduced into China in 2006, approximately 10 years after the introduction of an invasive whitefly, Bemisia tabaci (Genn.) B biotype. Even so the distribution and prevalence of TYLCV remained limited, and the economic damage was minimal. Following the introduction of Q biotype into China in 2003, the prevalence and spread of TYLCV started to accelerate. This has lead to the hypothesis that the two biotypes might not be equally competent vectors of TYLCV. METHODOLOGY/PRINCIPAL FINDINGS: The infection frequency of TYLCV in the field-collected B. tabaci populations was investigated, the acquisition and transmission capability of TYLCV by B and Q biotypes were compared under the laboratory conditions. Analysis of B. tabaci populations from 55 field sites revealed the existence of 12 B and 43 Q biotypes across 18 provinces in China. The acquisition and transmission experiments showed that both B and Q biotypes can acquire and transmit the virus, however, Q biotype demonstrated superior acquisition and transmission capability than its B counterparts. Specifically, Q biotype acquired significantly more viral DNA than the B biotype, and reached the maximum viral load in a substantially shorter period of time. Although TYLCV was shown to be transmitted horizontally by both biotypes, Q biotype exhibited significantly higher viral transmission frequency than B biotype. Vertical transmission result, on the other hand, indicated that TYLCV DNA can be detected in eggs and nymphs, but not in pupae and adults of the first generation progeny. CONCLUSIONS/SIGNIFICANCE: These combined results suggested that the epidemiology of TYLCV was aided differentially by the two invasive whiteflies (B and Q biotypes) through horizontal but not vertical transmission of the virus. This is consistent with the concomitant eruption of TYLCV in tomato fields following the recent rapid invasion of Q biotype whitefly in China

Genetic Variation of the Human α-2-Heremans-Schmid Glycoprotein (AHSG) Gene Associated with the Risk of SARS-CoV Infection

Genetic background may play an important role in the process of SARS-CoV infection and SARS development. We found several proteins that could interact with the nucleocapsid protein of the SARS coronavirus (SARS-CoV). α-2-Heremans-Schmid Glycoprotein (AHSG), which is required for macrophage deactivation by endogenous cations, is associated with inflammatory regulation. Cytochrome P450 Family 3A (CYP4F3A) is an ω-oxidase that inactivates Leukotriene B4 (LTB4) in human neutrophils and the liver. We investigated the association between the polymorphisms of these two inflammation-associated genes and SARS development. The linkage disequilibrium (LD) maps of these two genes were built with Haploview using data on CHB+JPT (version 2) from the HapMap. A total of ten tag SNPs were selected and genotyped. In the Guangzhou cohort study, after adjusting for age and sex, two AHSG SNPs and one CYP4F3 SNP were found to be associated with SARS susceptibility: rs2248690 (adjusted odds ratio [AOR] 2.42; 95% confidence interval [CI] 1.30-4.51); rs4917 (AOR 1.84; 95% CI 1.02-3.34); and rs3794987 (AOR 2.01; 95% CI 1.10–3.68). To further validate the association, the ten tag SNPs were genotyped in the Beijing cohort. After adjusting for age and sex, only rs2248690 (AOR, 1.63; 95% CI, 1.30–2.04) was found to be associated with SARS susceptibility. The combined analysis of the two studies confirmed tag SNP rs2248690 in AHSG as a susceptibility variant (AOR 1.70; 95% CI 1.37–2.09). The statistical analysis of the rs2248690 genotype data among the patients and healthy controls in the HCW cohort, who were all similarly exposed to the SARS virus, also supported the findings. Further, the SNP rs2248690 affected the transcriptional activity of the AHSG promoter and thus regulated the AHSG serum level. Therefore, our study has demonstrated that the AA genotype of rs2268690, which leads to a higher AHSG serum concentration, was significantly associated with protection against SARS development

Smartphone-Based Electrochemical Systems for Glucose Monitoring in Biofluids: A Review

As a vital biomarker, glucose plays an important role in multiple physiological and pathological processes. Thus, glucose detection has become an important direction in the electrochemical analysis field. In order to realize more convenient, real-time, comfortable and accurate monitoring, smartphone-based portable, wearable and implantable electrochemical glucose monitoring is progressing rapidly. In this review, we firstly introduce technologies integrated in smartphones and the advantages of these technologies in electrochemical glucose detection. Subsequently, this overview illustrates the advances of smartphone-based portable, wearable and implantable electrochemical glucose monitoring systems in diverse biofluids over the last ten years (2012&ndash;2022). Specifically, some interesting and innovative technologies are highlighted. In the last section, after discussing the challenges in this field, we offer some future directions, such as application of advanced nanomaterials, novel power sources, simultaneous detection of multiple markers and a closed-loop system