Research progress on the structure of crystal protein of Bacillus thuringiensis and its mechanism / 中国热带医学

@#Abstract: Mosquitoes are involved in the transmission of serious diseases such as malaria, dengue, chikungunya, yellow fever, Zika virus disease, and filariasis, and their prevention and control have always been a research hotspot. Currently, mosquito control methods mainly include physical control, chemical control and biological control. Physical control methods are environmentally friendly, but they are slow to take effect and have unsatisfactory control effects; although chemical control can quickly eliminate mosquitoes, it has been eliminated due to its high pollution, high residual, and easy drug resistance; biological control uses natural enemies or pathogens to kill mosquitoes and reduce their ability to transmit disease. Therefore, environmentally friendly biological control has become the main measure for controlling and preventing mosquitoes. In recent years, significant progress has been made in bacterial mosquito control agents, among which Bacillus thuringiensis has been the most extensively studied. Bacillus thuringiensis is a Gram-positive soil microorganism, which is the pathogenic bacterium of a variety of agricultural pests such as Lepidoptera, Coleoptera and Diptera. During the sporulation process, its strains produce a variety of insecticidal crystal proteins (ICPs) or δ-endotoxins with insecticidal activity against mosquito larvae. This review firstly introduces the crystal proteins of Bacillus thuringiensis, describes in detail the types and structures of crystal proteins in detail, and also reveals the mechanism of action of crystal proteins related to receptors.

Exploration and intervention of campus exclusive behavior from the perspective of evolutionary psychology / 中国学校卫生

Abstract@#Campus exclusion behavior attracts much attention in the filed of school-based social exclusion research field. It threatens the normal relationship and belonging acquisition of primary and secondary school students, resulting in frustration of students needs and negative emotions and behaviors, inability to handle classmates and social relationships well, and hindering mental health development of. Evolution believes that behaviors have a certain adaptive value. From the perspective of evolutionary psychology, a preliminary interpretation of the influencing factors of exclusion in terms of language, needs and motivations, and social status has been made. Resource acquisition, hunting-gathering hypothesis, homosexual competition, etc. Provides a certain evolutionary basis. Therefore, in the intervention and prevention of rejection behaviors, creating a campus atmosphere that accepts diversity has a positive effect on the guidance of all students, and strengthening emotional and cognitive interventions also alleviates the adverse effects of rejection behaviors.

Psychological flexibility training for career adaptability improvement among second-year middle-school students / 中国学校卫生

Objective@#To test the effectiveness of psychological flexibility training on career adaptability among middle school students who undertook psychological courses based on acceptance commitment therapy and the adolescent mental flexibility model(DNA-V), and to provide a reference plan to improve the mental health of middle school students.@*Methods@#This study recruited 110 junior high school students (60 boys and 50 girls) from a middle-school in Beijing. The students were randomly divided by class into a DNA-V face-to-face course group(offline group n=33), a DNA-V online course group(online group n=40), and a regular school psychology course group(control group n=37). Louise Hayes DNA-V intervention program was condensed into a six-hour middle-school DNA-V psychology curriculum. Using the Avoidance and Fusion Questionnaire for Youth and the Career Adaptability Scale, changes in psychological flexibility and career adaptability were measured before(T1), one week after(T2), and two months after (T3) the intervention.@*Results@#Linear mixed models were used for the analysis, while controlling for demographic variables. Psychological flexibility and career adaptability in the offline group were higher at T2 and T3 than at T1(psychological flexibility t=4.22, 3.11; career adaptablity t=3.05, 4.16, P<0.01), while the difference between T2 and T3 was not statistically significant. The psychological flexibility and career adaptability of the online group were not statistically significant at T1, T2, and T3. The psychological flexibility and career adaptability of the control group increased from T1 to T2(t=4.64, 2.47, P<0.05), but T3 decreased back to a level close to T1.@*Conclusion@#In terms of both psychological flexibility and career adaptability, the DNA-V face-to-face psychology course resulted in a retention period of at least two months.

Daily violence exposure and its impact on campus bullying among middle school students in Xinxiang / 中国学校卫生

Objective@#The study is to explore daily violence exposure and its association with campus bullying, to provide theoretical basis for positive development of middle school students.@*Methods@#Questionnaire survey was conducted by using Violence Exposure Scale, Normative Beliefs about Aggression Scale, Middle School Students’ Self-control Scale, and Middle School Students’ Campus Bullying Scale. During Aug. to Oct. 2019, 1 372 middle school students were selected by the convenient sampling method as subjects of study from 2 junior high schools and 3senior high schools in Xinxiang.@*Results@#The total score in daily violence exposure was (34.22±12.09). The scores of violence exposure, traditional bullying and cyberbullying in female were lower than in male(t=-2.60--6.32, P<0.05). The scores of violence exposure, traditional bullying and cyberbullying in junior high school students were higher than senior high school students(t=4.59-7.50, P<0.05). The relationship between violence exposure and normative beliefs about aggression, traditional bullying, cyberbullying were positive (r=0.20, 0.44, 0.51, P<0.01). The relationship between violence exposure and self-control was negative (r=-0.29, P<0.01) . The relationship between normative beliefs about aggression and traditional bullying, cyberbullying were positive (r=0.28, 0.22, P<0.01). The relationship between normative beliefs about aggression and self-control was negative (r=-0.38, P<0.01). Violence exposure indirectly affects traditional bullying/cyberbullying through normative beliefs about aggression. The effect of normative beliefs about aggression on the traditional bullying/cyberbullying of middle school students is reduced with the increase of self-control.@*Conclusion@#Normative beliefs about aggression plays an intermediary role in violence exposure and traditional bully/cyberbullying, and self-control regulates the relationship between them.

Mediation of stressful life events and online game intention in the relationship between role attachment and Internet game addiction among middle school students / 中国学校卫生

Objective@#To explore possible mediating effects of stressful life events and Internet game intention in the relationship between role attachment and Internet game addiction,and to provide a theoretical reference for preventing Internet game addiction among middle school students.@*Methods@#During Sept. to Dec. 2018, 1 869 middle school students were selected from 8 middle schools form Liaoning and Henan Province for this investigation through stratified random cluster sampling. Internet Gaming Role Attachment Scale, Adolescent Internet Game Addiction Scale, Adolescent Stressful Life Events Checklist and Adolescent Internet Game Intention Scale was administered.@*Results@#The prevalence of Internet game addiction was 5.00% in middle school students with boys(6.07%)signficantly higher than girls(3.57%)(χ2=5.29，P<0.01). Positive associations were found between Internet game addition with role attachment, stressful life events, Internet game intention (r=0.34-0.58, P<0.01). The results of Bootstrap test showed that stressful life events and Internet game intention had a chain intermediary effect between role attachment and Internet game addiction, and the chain intermediary effect accounted for 6.31% of the total effect.@*Conclusion@#Role attachment may affect the occurrence of Internet game addiction through stressful life events and Internet game intention. Helping middle school students to properly cope with stressful life events and Internet game intention may be beneficial for Internet game addiction prevention and intervention.

Mediation of shame in parent-child attachment and bullying among high school students / 中国学校卫生

Objective@#To explore mediating effect of shame on parent-child attachment and bullying among high school students, and to provide the basis for school bullying prevention among high school students.@*Methods@#From September to November 2018, a total of 1 149 students’ bullying behavior from 4 high schools in Shenyang and Xinxiang, were investigated with the Inventory of Parents and Peer Attachment, Middle School Students’ Bullying Scale and Middle School Students’ Shame Scale.@*Results@#About 31.07% of the subjects involved in school bullying. The report rates of bullying among boys, high school students of second grade, only child, students from rural area were higher (P<0.01). Mother-child attachment was negatively correlated with traditional and cyber bullying(r=-0.14, -0.21, -0.20, P<0.01). Father-child attachment was negatively correlated with traditional and cyber bullying(r=-0.19, -0.21, -0.19, P<0.01). Shame was positively correlated with traditional bullying and cyber bullying (r=0.20, 0.19, P<0.01). Shame mediates mother-child attachment, traditional and cyber bullying, accounting for 11.78% and 15.70% of the total effects. Shame mediates father-child attachment, traditional and cyber bullying, accounting for 15.17% and 17.43% of the total effect.@*Conclusion@#Mother-child and father-child attachment have direct effect on school bullying, and indirect effect on school bullying through shame.

Development and application of KASP marker for high throughput detection of AhFAD2 mutation in peanut

Background: Cultivated peanut (Arachis hypogaea L.) is a major oilseed crop worldwide. Fatty acid composition of peanut oil may affect the flavor and shelf life of the resulting food products. Oleic acid and linoleic acid are the major fatty acids of peanut oil. The conversion from oleic acid to linoleic acid is controlled by theΔ12 fatty acid desaturase (FAD) encoded byAhFAD2AandAhFAD2B, two homoeologous genes from A and B subgenomes, respectively. One nucleotide substitution (G:C→A:T) ofAhFAD2Aand an "A" insertion ofAhFAD2Bresulted in high-oleic acid phenotype. Detection ofAhFAD2mutation had been achieved by cleaved amplified polymorphic sequence (CAPS), real-time polymerase chain reaction (qRT-PCR) and allele-specific PCR (AS-PCR). However, a low cost, high throughput and high specific method is still required to detectAhFAD2genotype of large number of seeds. Kompetitive allele specific PCR (KASP) can detect both alleles in a single reaction. The aim of this work is to develop KASP for detectionAhFAD2genotype of large number of breeding materials. Results: Here, we developed a KASP method to detect the genotypes of progenies between high oleic acid peanut and common peanut. Validation was carried out by CAPS analysis. The results from KASP assay and CAPS analysis were consistent. The genotype of 18 out of 179 BC4F2seeds was aabb. Conclusions: Due to high accuracy, time saving, high throughput feature and low cost, KASP is more suitable fordeterminingAhFAD2genotype than other methods.

Uptake of DNA by cancer cells without a transfection reagent

BACKGROUND: Cancer cells exhibit elevated levels of glucose uptake and may obtain pre-formed, diet-derived fatty acids from the bloodstream to boost their rapid growth; they may also use nucleic acid from their microenvironment. The study of processing nucleic acid by cancer cells will help improve the understanding of the metabolism of cancer. DNA is commonly packaged into a viral or lipid particle to be transferred into cells; this process is called transfection in laboratory. Cancer cells are known for having gene mutations and the evolving ability of endocytosis. Their uptake of DNAs might be different from normal cells; they may take in DNAs directly from the environment. In this report, we studied the uptake of DNAs in cancer cells without a transfection reagent. METHODS: A group of DNA fragments were prepared with PCR and labeled with isotope phosphorous-32 to test their uptake by Huh 7 (liver cancer) and THLE3 (normal liver cells) after incubation overnight by counting radioactivity of the cells' genomic DNA. Multiple cell lines including breast cancer and lung cancer were tested with the same method. DNA molecules were also labeled with fluorescence to test the location in the cells using a kit of "label it fluorescence in situ hybridization (FISH)" from Mirus (USA). RESULTS: The data demonstrated that hepatocellular carcinoma cells possess the ability to take in large DNA fragments directly without a transfection reagent whereas normal liver cells cannot. Huh7 and MDA-MB231 cells displayed a significantly higher Rhodamine density in the cytoplasmic phagosomes and this suggests that the mechanism of uptake of large DNA by cancer cells is likely endocytosis. The efficacy of uptake is related to the DNA's size. Some cell lines of lung cancer and breast cancer also showed similar uptake of DNA. CONCLUSIONS: In the present study, we have revealed the evidence that some cancer cells, but not nontumorigenic cells, can take DNA fragments directly from the environment without the aid of the transfecting reagent.

Changes of cathepsin B in human photoaging skin both in vivo and in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cathepsin B plays an important role in cell cycle, extracellular matrix changes and cutaneous tumorigenesis: whether it plays a role in photoaged skin remains unknown. This study aimed to investigate the role of cathepsin B in skin photoaging in vivo and in vitro.</p><p><b>METHODS</b>The expressions of cathepsin B were compared with immunohistochemical methods in solar exposed skin and solar protected skin of six healthy Chinese volunteers. The mRNA and protein expression of cathepsin B in ultraviolet light A (UVA) induced premature senescence fibroblasts in vitro were detected by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting technique.</p><p><b>RESULTS</b>Decreased expression of cathepsin B was observed in photoaged skin compared with that of the solar protected skin. In the UVA induced, premature senescence fibroblasts, a lower expression of cathepsin B was detected by Western blotting and a decreased synthesis of cathepsin B mRNA in the same cells was revealed by real-time RT-PCR.</p><p><b>CONCLUSIONS</b>The results demonstrated a significant negative correlation between skin photoaging and cathepsin B in vitro and in vivo. We propose that cathepsin B, besides matrix metalloproteinases and antioxidant enzymes, is involved in the process of skin photoaging in that it contributes to extracellular matrix remodelling and is a dominant protease in cellular apoptosis and senescence.</p>

Association between HLA-DRB1, DQB1 genes and pemphigus vulgaris in Chinese Hans / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the predisposing role of HLA-DRB1, DQB1 genes in pemphigus vulgaris (PV).</p><p><b>METHODS</b>Polymerase chain reaction-specific sequence primers method was used to type HLA-DRB1, DQB1 subregion in the patients with PV of Han nationality from Jiangsu and Anhui provinces and matched control subjects.</p><p><b>RESULTS</b>DR4, DRB1*14(*1401,*1404,*1405) gene frequencies in PV patients were significantly higher than those in controls (Pc<0.05 and Pc<0.01 respectively). DQB1*0302, DQB1*0503 gene frequencies were significantly higher in PV patients (Pc<0.05). Further typing of DR4 positive subjects revealed that the gene frequencies of DRB1*0406, *0403 were significantly increased in PV patients as compared with controls (Pc<0.05). The haplotype frequencies of HLA-DRB1*04, DQB1*0302 and HLA-DRB1*14, DQB1*0503 in PV patients were significantly higher than those in controls (P<0.05).</p><p><b>CONCLUSION</b>The results suggest that the combination of HLA-DRB1*4, DQB1*0302 and HLA-DRB1*14, DQB1*0503 forms putative susceptible haplotypes for PV patients in Chinese Hans.</p>

Epidemiological and bacteriological characteristics of Neisseria gonorrhoeae isolates in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the antimicrobial susceptibility,auxotype, and plasmid profile of Neisseria gonorrhoeae isolates in China and to provide evidence for the development of treatment guideline and policy for control.</p><p><b>METHODS</b>Agar dilution was used to detect antimicrobial susceptibility. The auxotype was determined by GC genetic medium. The plasmid was extracted by alkaline cleavage and electrophoresed.</p><p><b>RESULTS</b>A total of 4,976 gonococcal isolates were tested in the last 8 years. The resistant rate for penicillin was 71.60% with PPNG being 15.54%. Tetracycline-resistant (TRNG) isolates accounted for 93.02% with 10.48% high level tetracycline-resistant. The resistant rate for ciprofloxacin was also relatively high (31.78%). The resistant rates for spectinomycin and ceftriaxone were 0.36% and 0.46%. The predominant auxotypes of gonococcal isolates were proto and pro(-) during 1995 - 1996 in Nanjing, accounted for 46.4% and 47.53%, 48.4% and 50.22%, respectively. There were 8 strains harboring 4.2, 5.4, 39.5 kb plasmids and 2 harboring 4.2, 4.9, 5.4, 39.5 kb plasmids in 10 PPNG strains; 2 harboring no plasmid, 28 harboring 4.2, 4.9, 5.4, 39.5 kb plasmids in 30 non-PPNG strains. The 5.4 kb plasmid of PPNG could be digested with restriction endonuclease BamHI while the 5.4 kb plasmid of non-PPNG could not.</p><p><b>CONCLUSION</b>The gonococcal isolates were highly resistant to penicillin, tetracycline, and ciprofloxacin, while were still sensitive to spectinomycin and ceftriaxone. No significant auxotyping change was found in terms of predominant gonococcal strains in the last two years in Nanjing while 5.4 kb plasmid might be the most prevalent resistant plasmid in Nanjing.</p>