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Objective@#To understand the vision status of primary and secondary school students in Beijing, in order to provide scientific reference for myopia prevention and control.@*Methods@#From 2018 to 2021, a stratified cluster sampling method was used to monitor myopia among 191 293 primary and secondary school students selected from 6 urban areas and 10 suburban areas in Beijing. Myopic screening was in accordance with the "standards for children and adolescents myopic screening", and was measured by an automatic desktop computer optometer under non-cycloplegic conditions. Statistical analysis was used by Chi-square test.@*Results@#The total myopia rate of primary and middle school students in Beijing from 2018 to 2021 were 60.7%, 57.6%, 59.2% and 59.7%, respectively. In 2018, the myopia rates of primary school students, middle school students, regular high school students and vocational high school students were 38.3%, 77.3%, 88.3% and 73.2% respectively. In 2019, they were 34.7%, 76.4%, 87.7% and 72.0%, respectively; in 2020, they were 37.5%, 76.8%, 86.8%, 74.9%; in 2021, they were 38.7%, 77.4%, 86.5% and 74.9 % respectively. Significant differences in educational stage were observed ( χ 2=7 386.07, 11 104.28, 9 850.08, 9 714.59, P <0.01). From 2018 to 2021, the overall myopia rate of girls (62.1%) was higher than that of boys (56.5%)( χ 2=613.75, P <0.01). The myopia rate of girls were higher than that of boys in each year, and significant differences in educational stage were observed, respectively( χ 2=120.47, 163.47, 168.01, 162.24, P <0.01). The overall myopia rate of urban students(63.0%) was higher than that of suburban students (56.0%)( χ 2=978.82, P <0.01). The myopia rate of urban students were higher than that of suburban students every year, and significant differences in educational stage were observed, respectively ( χ 2=86.71, 240.96, 302.56, 409.30 , P < 0.01 ).@*Conclusion@#The detection rate of myopia rate of primary and middle school students in Beijing is still high. It is necessary to strengthen the publicity and intervention of poor visual acuity in primary and middle school students, especially among urban area students, with the aim of effectively control and reduction in the myopia rate, and the improvement of student visual health.
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Objective@#To explore the association between reading and writing posture with the occurrence of myopia in Chinese children and adolescents, so as to provide a reference for reducing its prevalence among primary and secondary school students.@*Methods@#Using data from the 2020 survey on the current status of hyperopia reserve in primary and secondary school students from six provinces/cities, namely Beijing, Zhejiang, Chongqing, Shaanxi, Liaoning, and Henan selected by multi stage stratified cluster probability sampling method during November 2020 to June 2022. A total 16 782 students who completed the optometry examination of cycloplegia according to the Children and Adolescents Myopia Screening Standard and questionnaire survey were included for analyzing analyze the association between reading and writing posture with myopia.@*Results@#The overall detection rate of myopia among primary and secondary school students was 45.7%, of which 35.0% were primary school students, 84.1% junior high school students, and 90.4% senior high school students. Poor reading and writing posture was found in 73.6% of primary and secondary school students. Adjusting for confounding factors such as gender, school period, region, outdoor time every day, and whether parents were myopic, the results of the multilevel Logistic regression showed that the following factors were positively correlated with myopia:poor reading and writing posture ( OR=1.17, 95%CI =1.07-1.28), never/occasionally reading and writing with a reading distance which was more than one foot away between the eyes and book ( OR=1.28, 95%CI=1.08-1.53, OR=1.23, 95%CI = 1.08- 1.40), teachers occasionally reminding the child of their reading and writing posture ( OR=1.13, 95%CI =1.01-1.25), and often/always reading and writing while lying down or with the face on the arm ( OR=1.15, 95%CI=1.01-1.32, OR=1.46, 95% CI = 1.17-1.82), always reading and writing with the head in the hand ( OR=1.56, 95%CI =1.20-2.01). Further, a negative correlation was detected between myopia and parents occasionally reminding their children of their reading and writing posture ( OR= 0.85 , 95%CI =0.76-0.96) ( P <0.05).@*Conclusion@#Poor reading and writing posture is a risk factor for the development of myopia in primary and secondary school students, and interventions for reading and writing posture need to be strengthened to reduce the occurrence of myopia among primary and secondary school students.
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Objective@#To understand the current situation of teaching and living environment in primary and secondary schools in Beijing and to provide basis for further intervention.@*Methods@#According to the national plan, an annual average of 92 schools in 16 districts of Beijing were investigated from 2017 to 2020, including school drinking water, canteen, toilet, dormitory management and equipment allocation. Classroom environment of some schools were tested,including the per capita area of classrooms, the agreement rate of desks and chairs distribution, blackboard reflectance, the average illumination and uniformity of desks, the average illumination and uniformity of blackboards, and noise.@*Results@#From 2017 to 2020,most of schools provided water purifiers and direct drinking water, accounting for 85.1% of all investigated schools. The proportion of students canteens in urban schools was increasing,accounting for 90.5% of all schools in 2020. And there was little change in suburban schools,reaching 85.1% in 2020. The proportion of school toilets equipped with soap increased significantly, 92.0% of school toilets were equipped with soap in 2020. The proportion of student dormitories with a per capita area of less than 3 m 2 decreased by year, and all reached the standard in 2020. The qualified rates of various classroom testing indicators, including per capita area in classroom, desk illumination uniformity, and noises, were higher than 80%, while the qualified rates of the blackboard illumination uniformity, desk allotment were lower than 80%.@*Conclusion@#The teaching and living environment in Beijing has improved in recent years, but there are still some problems need to be solved.
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Objective@#To understand current situation of e cigarette use and associated factors in primary and secondary school students in Beijing, in order to promote the construction of smoke free schools.@*Methods@#During April to June in 2019, PPS sampling was used to select primary schools, secondary schools and trade schools. In each selected school, randomly sampling method was conducted until the sample size was reached. There were 18 312 students included in the analysis. Surveillance information mainly included the current situation of electronic cigarette use and associated factors.@*Results@#Among primary and secondary school students who have known about e cigarettes, female students were less likely to use e cigarettes than male students ( OR = 0.47 , 95% CI =0.42- 0.54 ). After entering the second year of junior high school, the possibility of using e cigarettes increased. Smoke free home was associated less e cigarettes usage ( OR =0.78, 95% CI =0.69-0.88). Primary and secondary school students with average daily allowance of 30~<150 yuan and no less than 150 yuan were 1.43 (95% CI =1.22-1.67) times and 2.24 (95% CI =1.79-2.79) times more likely to use e cigarettes than those with 0-10 yuan allowance, respectively. The probability of using e cigarettes among primary and secondary school students who have not tried using cigarettes was only 16.4% compared with those who have tried cigarettes ( OR =0.16, 95% CI =0.14-0.19).@*Conclusion@#It is necessary to curb the prevalence of e cigarettes among primary and secondary school students. Actions need to be taken urgently to fill in the gaps or correct the mistakes in children and adolescents cognition of e cigarettes, and to adopt more innovative methods to scientifically guide children and adolescents to stay away from e cigarettes.
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Objective@#To understand the current situation of tobacco use in primary and secondary school staff members in Beijing in 2019, and its association with adolescent tobacco use and exposure, in order to promote the construction of smoke-free schools.@*Methods@#During April to June in 2019，PPS sampling was used to select primary schools, secondary schools and vocational high school. Each selected school randomly investigates 20 faculty members, totalling 2 737. The monitoring contents mainly include the current tobacco use, knowledge and attitude towards health risk of smoking among the school staff.@*Results@#The faculty did not receive the training of adolescent tobacco control (OR=0.20,95%CI=0.14-0.28) were only 20% likely to teach tobacco hazard knowledge compared to the trained staff, and refusal to use tobacco control instruction manual (OR=0.21,95%CI=0.14-0.32) was negatively associated with teaching tobacco control with students. Staff members having given lectures on tobacco refusal were more inclined to uphold "any people can t smoke anywhere on campus "(98.53%), and the interpretation of the rules tends to be more clear. Staff who has been employed for 20-30 years (OR=3.35,95%CI=2.22-5.05) were the most probably to preach tobacco control among students(P＜0.05).@*Conclusion@#Staff caring about health and participate actively in health training were more willing to spread health knowledge. More attention should be paid to the cultivation of health literacy of school staff, and proactively guide faculty unwilling to instruct students in health hazard of smoking to gradually realize the importance of adolescent tobacco control.
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Objective@#To clarify the importance and practical significance of the standardized rate in primary healthcare work by comparing the differences in the prevalence of myopia in districts in Beijing before and after standardization.@*Methods@#This study recruited a total of 41 029 students from 107 primary and secondary schools and 35 kindergartens from the 16 districts of Beijing municipality. All participants underwent distance vision and refractive testing. The presence of myopia was defined as naked eye vision of <5.0 and non-ciliary muscle paralysis under computer optometry with a spherical equivalent objective refractive error of <-0.50 diopters (<-0.50 D). The student composition outlined in the 2018-2019 Beijing Education Development Statistics Summary was used as a standard group to standardize the prevalence of myopia in students from various districts of Beijing. The difference in the pre-and post-standardization rates was used to compare the change in myopia in each district before and after standardization.@*Results@#In 2018, the prevalence of myopia in students from Beijing was 57.3%. Stratified by school period, the prevalence of myopia in preschool, primary school, junior high school, ordinary high school, and vocational high school students was 12.1%, 38.4%, 77.2%, 88.3%, and 73.1%, respectively. Although the prevalence of myopia in Daxing District was the highest both before and after standardization, the difference in the prevalence rate was 13.8 percentage points. The prevalence of myopia in Miyun District was the lowest before standardization. However, after standardization, the prevalence of myopia was lowest in Huairou District.@*Conclusion@#The prevalence of myopia among Beijing students is generally high. Before and after standardization, the prevalence of myopia in different districts was quite different. The results show that, in practice, the standardized prevalence can reveal the true epidemiological characteristics of specific disease.
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Objective@#To evaluated the application of General Provisions of Safety and Health for Writing Boards(GB 28231-2011), and to provide basis for the revision and improvement of the standard.@*Methods@#From June to October 2018, a questionnaire survey was conducted among 852 people engaged in the evaluation, use and production of writing boards in 8 districts of Beijing, Liaoning and Jiangsu. The contents of the survey include the awareness, implementation of the standard and evaluating the use of various parameters in the standard by personnel from different institutions.@*Results@#The overall awareness ratio of the standard among staffs from health, education and enter prise was 78.26%. For the nominal size of the writing board and the vertical distance between the lower edge and the platform, the reasonableness considered lower by health professionals(62.50%, 37.50%) than that of education professionals(90.00%, 90.00%) and enterprise staffs(90.00%, 90.00%)(P<0.05); For the frequency and reasonableness of the nine parameters such as gloss and adhesion, the perception of each institution were significantly different(P<0.05), with proportion of professionals in health lower than experts in education and enterprise. For the two parameters of color and light resistance, each institution considered the maneuverability was not strong(P>0.05).@*Conclusion@#Propagation and implement is still needed to strengthen comprehension, because different institutions have different understandings towards the standard. There are still some problems waiting to be solved, such as different standard limits, poor enforceability of two parameters which are writing board color and light resistance.
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Objective@#To observe the joint effect of school and family tobacco control on middle school students, and to explore its effectiveness in reducing second-hand smoke exposure in middle school students’ families, as so asto provide a new way of thinking for controlling smoking among middle school sudents.@*Methods@#A questionnaire survey was conducted on the study of 2 125 primary and high school students in four middle schools in the Dongcheng District of Beijing by means of a stratified group sampling method. Personal information of students, tobacco control environment around the family, school and surrounding ares, as well as the knowledge, attitude and behavior of students related to tobacco control was collected.@*Results@#The exposure rate of second-hand smoke in the families of middle and high school students in Dongcheng District of Beijing was 33.41%. Smoking by at least one parent was positively correlated with second-hand smoke exposure in the student’s home (OR=22.88, P<0.05). Among the students who saw the "clear no-smoking label" on campus, the exposure rate (4.92%) when the smoking restriction was set on the home was lower than that of those who did not have a regulation in the home (58.94%) (χ2=452.57, P<0.01). The results of Logistic regression showed that there was a combination of family smoking restrictions and second-hand smoke exposure in middle and high school students who had seen the smoking ban on campus (OR=0.08) and had the school’s tobacco control education (OR=0.08).@*Conclusion@#The joint tobacco control measures between school and family can effectively reduce the exposure rate of second-hand smoke in middle school students’ families, which is better than the effect of tobacco control alone.
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Objective@#To understand the sanitation status of teaching environment of schools in Beijing, and to provide basis for school environmental improvement through monitoring it.@*Methods@#In 2019, 661 primary and secondary schools were selected according to the coverage rate of 50% of all schools. Two classrooms were randomly selected from each school for testing, 1 322 classrooms were monitored. The testing contents included per capita area of the classroom, rate of correct desks-chairs adjusting for school height, blackboard size, reflection ratio of blackboard,illumination, carbon dioxide and noise.@*Results@#The qualified rate of noise(92.3%), per capita area(86.5%), blackboard size (85.6%) and illumination uniformity of table top (83.4%) were higher than 80%, while the qualified rate of other indexes were lower than 80%. In 2019, the qualified rate of blackboard size, blackboard average illuminance and blackboard illuminance uniformity were higher than 2018 year(85.6%, 52.7%, 36.2%; 81.9%, 42.7%, 31.7%)(χ2=10.97, 7.80, 5.90, P<0.05), while the noise (92.3%) was lower than 2018 year(98.3%)(χ2=70.82, P<0.05). Both classroom and blackboard, the average illuminance and evenness of the desk and blackboard installed with LED light were higher than those installed with fluorescent lights.@*Conclusion@#Teaching environment monitoring in Beijing is not optimistic. It is necessary to strengthen the promotion and evaluation of standards,and the classroom environment needs to be further improved.
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Objective; To investigate the inhibitory effect of resveratrol on the pulmonary inflammation in the mice with neutrophilic asthma, and to elucidate its mechanism. Methods; A total of 18 female C57BL/6J mice were selected. The mouse models of neutrophilic asthma were established by sensitization with lipopolysaccharide (LPS) and ovalbumin (OVA). The model mice were randomly divided into model group (LPS + OVA group), resveratrol group (Res group, intragastric administration of 30 mg. kg-1 resveratrol at 2 h before challenge) and N-acetylcysteine group (NAC group, intragastric administration of 3 mmol · kg-1 N-acetylcysteine at 2 h before challenge). Other 6 age-matched female C57BL/6J mice were choosen as normal control group (PBS group). The behavioral changes of mice in various groups were observed during the atomization with methacholine; the airway hyperresponsiveness (AHR) of mice was analyzed with a lung function instrument, and the total number of cells and inflammatory cells in the bronchoalveolar lavage fluid (BALF) were observed with light microscope; the pathological changes of lung tissue were observe by HE staining; the levels of interleukin-17 (IL-17) in the supernatant of BALF of the mice in various groups were detected by enzyme-linked immunosorbent assay (ELISA); the level of reactive oxygen species (ROS) in lung tissue was analyzed by specific fluorescent probe DCF-DA staining; the level of malondialdehyde (MDA) in lung homogenate was measured by MDA kit. Results: Compared with PBS group, the Penh value, total number of cells, inflammatory cells, airway inflammation and scores of the mice in LPS+OVA group were significantly increased (P<0. 05 or P<0. 01); the IL-17 level in BALF supernatant was significantly increased (P<0. 01); the ROS fluorescence intensity in lung tissue was significantly increased, and the MDA level in lung homogenates was significantly increased (P<0. 01). Compared with LPS + OVA group, the Penh value, total number of cells, inflammatory cells, airway inflammation and scores in Res group and NAC group were significantly decreased (P<0. 05 or P<0. 01); the IL-17 levels in BALF supernatant were significantly decreased (P<0. 05 or P<0. 01); the ROS fluorescence intensities in lung tissue were decreased, and the MDA levels in lung homogenates were significantly decreased (P < 0.01). Conclusion: Resveratrol can effectively inhibit the inflammatory response of lung tissue in the mice with neutrophilic asthma, and its mechanism may be related to inhibiting the oxidative stress reaction.
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Objective To test the antimicrobial susceptibility of Staphylococcus aureus from children with impetigo,and to assess the differences in randomly amplified polymorphic DNA profiles between sensitive and resistant Staphylococcus aureus strains.Methods Secretion specimens were obtained from the impetiginous lesions of 178 children,and subjected to bacterial culture.The susceptibility of 162 Staphylococcus aureus isolates against 21 antibiotics was tested.Randomly amplified polymorphic DNA PCR(RAPD-PCR)was performed to characterize the genotype of Staphylococcus aureus.Results Totally,180 bacterial strains were isolated from 178 children with impetigo in Chengdu,including 162(90.00％)Staphylococcus aureus strains.Of the 162 Staphylococcus aureus strains,148 were methicillin sensitive Staphylococcus aureus(MSSA),14 methicillin resistant Staphylococcus aureus(MRSA).The most active antibiotic was minocycline,followed by teicoplanin,quinupristin,vancomycin and nitrofurantoin,while the resistance rate to penicillin was highest,followed by that to erythromycin,clindamycin,compound sulfamethoxazole and tetracycline.All the Staphylococcus aureus isolates were sensitive to fusidic acid,nitrofurantoin,vancomycin,minocycline and teicoplanin.According to RAPD-PCR,the 162 Staphylococcus aureus strains were divided into 8 genotypes,with the three most prevalent genotypes being Ⅲ(31.48％),Ⅱ(26.54％)and Ⅵ(25.93％),which accounted for 65.43％(106/162)in all the strains.The 148 MSSA strains fell into 8 genotypes,with genotype Ⅲ(50 strains,33.78％),Ⅵ(39 strains,26.35％)and Ⅱ(33 strains,22.30％)being the most prevalent genotypes;the 14 MRSA strains fell into 3 genotypes,i.e.,genotype Ⅱ(10 strains,71.43％),Ⅵ(3 strains,21.43％),and Ⅲ(1 strain,7.14％).Conclusions Staphylococcus aureus is the most prevalent pathogenic bacteria in children with impetigo in Chengdu area,which is highly sensitive to minocycline,teicoplanin and quinupristin,and falls into 8 genotypes according to RAPD-PCR with genotype Ⅲ being the most common genotype.
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<p><b>BACKGROUND</b>Because of the potential proarrhythmic effect of current antiarrhythmic drugs, it is still desirable to find safer antiarrhythmic drugs worldwide. Paeoniflorin is one of the Chinese herb monomers that have different effects on many ion channels. The present study aimed to determine the effects of paeoniflorin on cardiac ion channels.</p><p><b>METHODS</b>Whole-cell patch-clamp technique was used to record ion channel currents. L-type calcium current (I(Ca-L)), inward rectifier potassium current (I(K1)), and transient outward potassium current (I(to1)) were studied in rat ventricular myocytes and sodium current (I(Na)), slow delayed rectifier current (I(Ks)), and HERG current (I(Kr)) were investigated in transfected human embryonic kidney 293 cells.</p><p><b>RESULTS</b>One hundred µmol/L paeoniflorin reduced the peak I(Ca-L) by 40.29% at the test potential of +10 mV (from (-9.78 ± 0.52) pA/pF to (-5.84 ± 0.89) pA/pF, n = 5, P = 0.028). The steady-state activation curve was shifted to more positive potential in the presence of the drug. The half activation potentials were (-11.22 ± 0.27) mV vs. (-5.95 ± 0.84) mV (n = 5, P = 0.007), respectively. However, the steady-state inactivation and the time course of recovery from inactivation were not changed. One hundred µmol/L paeoniflorin completely inhibited the peak I(Na) and the effect was reversible. Moreover, paeoniflorin inhibited the I(K1) by 30.13% at the test potential of -100 mV (from -25.26 ± 8.21) pA/pF to (-17.65 ± 6.52) pA/pF, n = 6, P = 0.015) without effects on the reversal potential and the rectification property. By contrast, 100 µmol/L paeoniflorin had no effects on I(to1), I(Ks) or I(Kr) channels.</p><p><b>CONCLUSIONS</b>The study demonstrated that paeoniflorin blocked I(Ca-L), I(Na), and I(K1) without affecting I(to1), I(Ks), or I(Kr). The multi-channel block effect may account for its antiarrhythmic effects with less proarrhythmic potential.</p>
Subject(s)
Animals , Humans , Male , Rats , Anti-Inflammatory Agents, Non-Steroidal , Pharmacology , Benzoates , Pharmacology , Bridged-Ring Compounds , Pharmacology , Drugs, Chinese Herbal , Pharmacology , Glucosides , Pharmacology , Heart , In Vitro Techniques , Ion Channels , Monoterpenes , Patch-Clamp Techniques , Rats, Sprague-DawleyABSTRACT
Objective To study the biological characteristics of arsenic resistance cell model chronic arsenic exposure human bone marrow mesenchymal stem cells (CAsE-hFBMSCs) and discuss the consequence of chronic arsenite exposure to human mesenchymal stem cells (hFBMSCs). Methods hFBMSCs cultivated under general conditions,hFBMSC cell survival rate was detected in 48 hours with arsenite toxicity test under different doses arsenic [0(control),0.25,0.50,1.00,2.00,4.00,8.00,20.00,40.00,80.00,120.00 μmol/L]of the fist 2-generation(P2). According to the test results,1.00 μmol/L sodium arsenite was chosen to stimulate hFBMSCs for 14 weeks as experimental group,simultaneous 0 μmol/L sodium arsenite as the control group. And then,the phenotype was detected by fluorescence-activated cell sorting,and the cell cycle by flow cytometry. Finally,the cell malignant transformation was detected by soft-agar assay. Results Arsenite low than 10 μmol/L promoted cell proliferation,but inhibited cell proliferation when exceeding 10 μmol/L. Half of the lethal dose (LC_(50)) in experimental and control groups were (89.42±0.64),(52.48±0.71)μmol/L. The difference between two groups was statistically significant(t = 123.89,P < 0.05). The phenotype of CAsE-hFBMSCs was CD29,CD90,CD166 positive and CD34,CD45 negative. The phenotype of CAsE-hFBMSCs was the same as the control. Comparing to control group[(8.44±0.45)%,(9.14μ0.14)%,(82.42±0.60)%],G2/M phage[(17.72±5.47)%]and S phage [(25.34±3.36)%]cell increased,G0/G1 phage[(56.96±8.83)%]cell decreased in P2 CAsE-hFBMSCs. The cell cycle became nearly the same as the control group after adaption. CAsE-hFBMSCs did not show clone formation in soft agar clone formation assay. Conclusion Long last and low level exposure to arsenite does not influence the biologic features of hFBMSCs.
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<p><b>BACKGROUND</b>Imbalance of the sympathetic nervous system was involved in the pathogenesis of idiopathic ventricular outflow-tract tachycardia (IVOT). We aimed to investigate whether the major genetic variants in β(1)- and β(2)-adrenoceptors and GNB3 C825T were associated with IVOT and verapamil sensitive idiopathic left ventricular tachycardia (ILVT).</p><p><b>METHODS</b>Patients with IVOT and ILVT from December 2005 to December 2007 were consecutively enrolled into this study. Controls were randomly selected from the community-based inhabitants. Five genetic variants, Ser49Gly and Gly389Arg in the β(1)-adrenoceptor, Arg16Gly and Gln27Glu in the β(2)-adrenoceptor and GNB3 C825T, were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis.</p><p><b>RESULTS</b>A total of 227 patients with IVOT and 110 patients with ILVT were included. Genotyping revealed that the 16Gly allele of Arg16Gly variant of β(2)-adrenoceptor was associated with a higher risk of IVOT (OR: 1.40, 95%CI: 1.12 - 1.75, P = 0.003 in the addictive model and OR: 1.62, 95%CI: 1.14 - 2.31, P = 0.007 in the dominant model). Patients with Gly16Gln27 haplotype also had a higher risk of IVOT (OR: 1.38, 95%CI: 1.11 - 1.73, P = 0.012). Other four variants, including Ser49Gly and Arg389Gly in β(1)-adrenoceptor, Gln27Glu in β(2)-adrenoceptor and GNB3 C825T, did not differ between patients with IVOT and controls. In patients with ILVT, no significant difference was found in these five variants compared with controls.</p><p><b>CONCLUSIONS</b>Arg16Gly in β(2)-adrenoceptor is significantly associated with IVOT in Chinese Han population. Major genetic variants in β(1)- and β(2)-adrenoceptor and GNB3 C825T may not be associated with ILVT. These data suggest a different arrhythmogenic mechanism in IVOT and ILVT.</p>
Subject(s)
Adult , Humans , Male , Middle Aged , Genetic Predisposition to Disease , Genetic Variation , Genotype , Haplotypes , Receptors, Adrenergic, beta-1 , Genetics , Receptors, Adrenergic, beta-2 , Genetics , Sex Characteristics , Tachycardia, Ventricular , Genetics , Ventricular FunctionABSTRACT
Growth of animal is largely regulated by growth hormone (GH). In this study, the GH gene was isolated and cloned from the genomic DNA library from Rongjiang pig, a Chinese local swine, using polymerase chain reaction technique. The complete nucleotide sequence of a 1.903 kb genomic fragment containing Rongjiang swine GH gene has been determined. The GH gene contained five exons and four introns similar to the GH genes of other mammalians and exhibited 97%~99% identity to the GH genes of the four western meat-type breeds and nine Chinese local pigs. Polymorphism of GH genes was analyzed by using the restriction enzymes Dde I, Nar I and BsmN I in four western meat-type breeds and ten Chinese local pigs. Five polymorphic restriction sites, with Dde I at the base 622 (G/A) in exon 2 and 274 (T/C) in 5o-flank, with Nar I at 631 (G/A) in exon 2, and with BsmN I at the base 841 (T/C) in intron 2 and 1358 (A/G) in exon 4, were identified. The polymorphic restriction site at 1358 (A/G) leaded to the GH mature protein of Rongjiang pig differing from that of four western meat-type breeds and eight Chinese local breeds at the residue Val108 substituted by Ile108. According to the crystal structure of human GH mature protein, this Ile108 substitution might result in a lower affinity of GH for its receptor in Rongjiang breed.
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Animals , Breeding , China , Cloning, Molecular , Exons , Growth Hormone , Genetics , Physiology , Introns , Polymerase Chain Reaction , Polymorphism, Genetic , Polymorphism, Restriction Fragment Length , Species Specificity , SwineABSTRACT
Gonadotropin-releasing hormone (GnRH) and dopamine (DA) can stimulate growth hormone (GH) release, but their effects on GH mRNA synthesis are controversial and deficient in fish. Orange-spotted grouper (Epinephelus coioides) is a hermaphroditic marine fish with sex reversal. Few data are available concerning the regulation of GH in grouper. In the present study, the effects of GnRH and DA on GH release and GH mRNA expression were determined using pituitary fragments of orange-spotted grouper under static culture conditions. After incubation from 1 h to 24 h, salmon GnRH (sGnRH, 100 nmol/L) stimulated the release of GH and increased the level of GH mRNA time-dependently. The minimum duration of sGnRH effect was 1 h. Both of sGnRH and mammalian GnRH (mGnRH) augmented the release of GH and the level of GH mRNA in a dose-dependent manner. The potency of sGnRH on both GH release and GH mRNA level was more pronounced than that of mGnRH. The effects of 1 micromol/L APO (Apomorphine), an agonist of D(1)/ D(2) dopamine receptors, significantly stimulated GH release and GH mRNA synthesis after incubation for 12 h. APO stimulated GH release and GH mRNA abundance in a dose-dependent manner. These results demonstrate that both GnRH and DA directly stimulate GH release and GH mRNA expression at the pituitary level, the actions of GnRH are more potent than that of DA in orange-spotted grouper.