Free PSA performs better than total PSA in predicting prostate volume in Chinese men with PSA levels of 2.5-9.9 ng ml-1 / 亚洲男科学杂志(英文版)

This study investigated whether free prostate-specific antigen (fPSA) performs better than total PSA (tPSA) in predicting prostate volume (PV) in Chinese men with different PSA levels. A total of 5463 men with PSA levels of <10 ng ml-1 and without prostate cancer diagnosis were included in this study. Patients were classified into four groups: PSA <2.5 ng ml-1, 2.5-3.9 ng ml-1, 4.0-9.9 ng ml-1, and 2.5-9.9 ng ml-1. Pearson/Spearman's correlation coefficient (r) and receiver operating characteristic (ROC) curves were used to evaluate the ability of tPSA and fPSA to predict PV. The correlation coefficient between tPSA and PV in the PSA <2.5 ng ml-1 cohort (r = 0.422; P < 0.001) was markedly higher than those of the cohorts with PSA levels of 2.5-3.9 ng ml-1, 4.0-9.9 ng ml-1, and 2.5-9.9 ng ml-1 (r = 0.114, 0.167, and 0.264, respectively; all P ≤ 0.001), while fPSA levels did not differ significantly among different PSA groups. Area under ROC curve (AUC) analyses revealed that the performance of fPSA in predicting PV ≥40 ml (AUC: 0.694, 0.714, and 0.727) was better than that of tPSA (AUC = 0.545, 0.561, and 0.611) in men with PSA levels of 2.5-3.9 ng ml-1, 4.0-9.9 ng ml-1, and 2.5-9.9 ng ml-1, respectively, but not at PSA levels of <2.5 ng ml-1 (AUC: 0.713 vs 0.720). These findings suggest that the relationship between tPSA and PV may vary with PSA level and that fPSA is more powerful at predicting PV only in the ''gray zone'' (PSA levels of 2.5-9.9 ng ml-1), but its performance was similar to that of tPSA at PSA levels of <2.5 ng ml-1.

Preparation of human monoclonal antibody against SARS-CoV-2 spike protein using single B cell / 中国生物制品学杂志

@#Abstract：Objective To prepare human monoclonal antibody against spike protein（S protein）of severe acute respiratory syndrome coronavirus 2（SARS⁃CoV⁃2）by using single B cell，and determine its neutralizing activity. Methods Venous blood with high antibody level was collected from people immunized with inactivated SARS⁃CoV⁃2 vaccine（Vero cells） twice，of which peripheral blood mononuclear cells（PBMCs）were isolated by lymphocyte stratified fluid and used to isolate single B cell expressing S protein antibody by magnetic beads coupled with S1 protein. Variable region genes of IgG heavy chain and light chain were amplified by nested PCR after reverse transcription of single B cell，which were connected with CMV promoter，IgG leader sequence，IgG constant region and polyA sequence by overlapping PCR to construct antibody linear expression cassette. Linear expression cassette of the heavy chain and light chain from the same B cell was transfected to HEK293T cells to express human monoclonal antibody of SARS⁃CoV⁃2 S protein. Immunoreactivity was detected by immuno⁃ fluorescence while neutralizing activity by pseudovirus neutralization test. Results A total of 26 monoclonal antibodies against SARS⁃CoV⁃2 S protein were expressed，which showed heavy chain and light chain protein bands of IgG antibody at

Characteristics of fat free mass among middle and high school adolescents in Yinchuan City / 中国学校卫生

Objective@#To elucidate age and sex specific characteristics in fat free mass (FFM) among middle and high school adolescents in Yinchuan City, China, and to provide a scientific basis for healthy development, chronic disease prevention and intervention in children and adolescents.@*Methods@#Using a convenient cluster sampling method, 1 175 middle and high school adolescents, aged 10 to 20 years old, from Yinchuan, China, were selected to participate in a questionnaire survey and physical examination, which involved body composition by bioelectrical impedance analysis(BIA).@*Results@#For adolescents aged 12 to 18 years, FFM and the fat free mass percentage (FFMP) of boys increased with age(from 39.78 to 52.63 kg; 77.51% to 83.80%, respectively), the age trends of the FFM and FFMP of body parts were in the similar pattern, and were significantly higher than those of girls(all P <0.05). In girls, the FFM reached a peak of 40.96 kg at 15 years old, and decreased slightly between the ages of 15 and 18 years, the age trends of the FFM of body parts were in the similar pattern, and the FFMP decreased with age (from 75.63% to 71.91 %). In addition, in girls, the age trends of the FFMP of left and right legs were the same as the general trend, while the FFMP of left and right arms increased with age. The FFMP of the trunk reached a minimum of 29.93% at 15 years old and increased from 15 to 18 years old(all P <0.05).@*Conclusion@#For middle and high school adolescents aged 12 to 18 years old in Yinchuan City, China, the distribution of FFM changed in accordance with age and gender differences, in accordance with the characteristics of the adolescents growth and development.

Relationship between body mass index, waist circumference and waist circumference height ratio and bone metabolism markers in Yinchuan middle school students / 中国学校卫生

Objective@#To analyze the relationship between body mass index (BMI), waist circumference (WC), waist to height ratio (WHtR) and bone metabolism markers.@*Methods@#By using the method of cluster sampling, a total of 1 084 adolescents aged 12 to 18 from one middle school in Yinchuan were investigated by questionnaire, physical examination and laboratory examination during sept. to Dec., 2018.@*Results@#BMI, WC and WHtR were significantly negatively correlated with Ca (r=-0.10, -0.15, -0.15, P<0.05), and WC was negatively correlated with β-CTX(r=-0.06 P<0.05). After adjusting for age, sex and vitamin D supplementation, WC had significant effects on Ca and β-CTX(β=-0.33, -0.22, P<0.05). Logistic regression analysis showed that there was no significant relationship between different types of obesity and the level of OC(P>0.05). The level of serum β-CTX in obese students was 1.93 times higher than that in normal students, Ca serum levels of obese students was 0.31 times higher than that in normal students that in abdominal obese students (defined as WC) was 0.54 times higher than that in normal students.@*Conclusion@#BMI, WC and WHtR were correlated with OC, β-CTX and Ca in adolescents in Yinchuan city, and WC was more closely related to Ca and β-CTX, suggesting that obesity has a negative effect on bone absorption.

Association of cardiovascular disease risk factors with fat mass percentage and waist circumference in children and adolescents in Yinchuan City / 中国学校卫生

Objective@#To analyze the association between fat mass percentage (FMP) and waist circumference (WC) with cardiovascular risk factors in children and adolescents in Yinchuan City, and to provide a reference for preventing and contyolling the risk factors of cardiovascular diseases among children and adolescents.@*Methods@#A questionnaire survey, physical examination, body composition determination and biochemical tests were conducted among 1 043 children aged 12-18 years in Yinchuan selected through a convenient cluster sampling method.@*Results@#Among boys and girls, both FMP and WC were associated with high rate of high blood pressure and high TG in children and adolescents(P<0.01). The increased risk of metabolic abnormalities by FMP and WC were 1.14-2.36 times and 1.32-2.09 times, respectively. About 4.9%-22.1% of cardiovascular disease risk was explained by the combination of FMP and WC, which was significantly higher than separate interpretation of FMP or WC (3.5%-22.0%). Standardized regression coefficient for TC and LDL-C (0.25 and 0.22) was greater than WC (0.17 and 0.14) by FMP, and the absolute value of the standardized regression coefficient for SBP, DBP, TG, HDL-C was less than WC by FMP. The predictive risk for high blood pressure, high TG, high TC, low HDL-C and high LDL-C by combination of FMP and WC was 3.67(95%CI=2.42-556), 3.09(95%CI=2.04-4.69), 3.37(95%CI=1.38-8.28), 2.00(95%CI=1.35-2.98) and 4.73(95%CI=2.15-10.44) times higher than different combinations risk groups(P<0.01).@*Conclusion@#The ability of fat mass percentage and waist circumference to predict the risk of cardiovascular risk factors is similar. It might be used as a predictor of cardiovascular risk factors in children and adolescents. It is recommended to combine FMP with WC to predict the risk of cardiovascular disease among children and adolescents.

Blood pressure and blood biochemical indexes between obese students and normal-weight middle school students in urban area of Yinchuan / 中国学校卫生

Objective@#To analyze the differences of cardiovascular(CV) risk factors between middle school students with normal weight but high body fat and students with normal weight and normal body fat in urban area of Yinchuan,to provide a theoretical basis for early detection of their invisible obesity and controlling CV metabolism disease.@*Methods@#During 2017 to 2018, a total of 1 043 secondary school students in urban area of Yinchuan were selected through cluster sampling. Questionnaire survey, physical examination, body composition and blood lipid test were conducted among all the participants.745 middle school students with normal body mass index (BMI) were included in the analysis.@*Results@#Nearly 31.1% students with normal BMI had high body fat, with girls significantly higher than that in boys across different age groups(χ2=10.37，106.49，P<0.01). Total cholesterol (TC) in boys with normal-weight obesity was higher than that in the normal group, while diastolic blood pressure (DBP), triglyceride (TG), TC and lowdensity lipoprotein cholesterol (LDL-C) in girls with normal-weight obesity were significantly higher than that in the normal group, with statistically significant differences (t=-2.37，-3.82，-3.48，-4.46，-4.68，P<0.01). The detection rates of high blood pressure, high TC level and high LDL-C level in normalweight obese girls were all higher than those in normal group (χ2=4.17，8.77，5.91，P<0.05). The detection rate of CV risk factors ≥2 in normal-weight obesity group was higher than that in the normal group, and the difference was statistically significant(χ2=7.05，P<0.01).@*Conclusion@#Normal-weight obesity among middle school students in urban area of Yinchuan is prevalent, which is mainly concentrated in female students. Moreover, cardiovascular risk factors are more common among those normal-weight obese students compared with normal students. Interventions for preventing and controlling normal-weight obesity should be developed and implemented as early as possible.

PhoR/PhoP two component regulatory system affects biocontrol capability of Bacillus subtilis NCD-2

The Bacillus subtilis strain NCD-2 is an important biocontrol agent against cotton verticillium wilt and cotton sore shin in the field, which are caused by Verticillium dahliae Kleb and Rhizoctonia solani Kuhn, respectively. A mutant of strain NCD-2, designated M216, with decreased antagonism to V. dahliae and R. solani, was selected by mini-Tn10 mutagenesis and in vitro virulence screening. The inserted gene in the mutant was cloned and identified as the phoR gene, which encodes a sensor kinase in the PhoP/PhoR two-component system. Compared to the wild-type strain, the APase activities of the mutant was decreased significantly when cultured in low phosphate medium, but no obvious difference was observed when cultured in high phosphate medium. The mutant also grew more slowly on organic phosphate agar and lost its phosphatidylcholine-solubilizing ability. The suppression of cotton seedling damping-off in vivo and colonization of the rhizosphere of cotton also decreased in the mutant strain when compared with the wild type strain. All of these characteristics could be partially restored by complementation of the phoR gene in the M216 mutant.