[Urban-rural disparities of depression symptoms and its influencing factors among the elderly aged ≥65 years old in Anhui Province from 2019 to 2020]

Objective: To analyze the difference in depression symptoms and influencing factors between urban and rural elderly people aged ≥65 years old in Anhui Province. Methods: Based on the data from a survey of 68 communities in Anhui Province that implemented the National Elderly Psychological Care Project from 2019 to 2020, the current status of depression symptoms in the elderly was evaluated using the Patient Health Questionnaire-9 (PHQ-9). The difference in the detection rate of depression symptoms between urban and rural elderly people with different characteristics was compared by using the χ2 test. The logistic regression model was used to analyze the relevant factors of depression symptoms in urban and rural elderly people. Results: A total of 15 532 elderly people aged≥65 years old were included in the survey. The detection rate of depressive symptoms was 7.12%, which was higher in rural areas (9.08%) than in urban areas (6.48%). Logistic regression showed that chronic diseases were risk factors for depressive symptoms in elderly people from both urban and rural areas. Positive attitudes towards aging and good mental resilience were protective factors for depressive symptoms in elderly people. Having hobby (OR=0.64, 95%CI: 0.45-0.91), good relationship with children (OR=0.56, 95%CI: 0.41-0.76), good relationship with spouse (OR=0.51, 95%CI: 0.37-0.71), and having at least 6 friends (OR=0.48, 95%CI: 0.32-0.71) were the protective factors for depressive symptoms in urban elderly people. A good relationship with neighbors (OR=0.58, 95%CI: 0.41-0.82) and having 1-2 friends (OR=0.40, 95%CI: 0.25-0.64) were the protective factors for depressive symptoms in rural elderly people. Women (OR=1.49, 95%CI: 1.06-2.10) and higher education level (OR=1.81, 95%CI: 1.19-2.74, compared with illiterate/semi-illiterate in primary school; OR=2.94, 95%CI: 1.82-4.76, compared with illiterate/semi-illiterate in junior high school and above) were the risk factors for depressive symptoms in rural elderly people. Conclusion: There are differences between urban and rural areas in depressive symptoms among elderly people in Anhui Province. The detection rate of depression symptoms among rural elderly people is higher, and the influencing factors of depressive symptoms between urban and rural elderly people are also different, which should be treated specifically in the implementation of intervention measures.

[A cross-sectional study of prevalence of chronic kidney disease and related factors in adults in Anhui province]

Objective: To understand the prevalence of chronic kidney disease (CKD) and related factors in adults in Anhui province based on the data of Chinese Chronic Diseases and Nutrition Surveillance program (2018) in Anhui. Methods: Multi-stage stratified cluster random sampling was used to select participants aged ≥18 years. Moreover, questionnaire survey, body measurements and laboratory tests were conducted. The complex weighting method was used to estimate the prevalence of CKD in residents with different characteristics, and complex sampling data logistic regression model was used for multivariate analysis to identify related risk factors. Results: A total of 7 181 participants were included. The overall prevalence of CKD was 11.06% in adults in Anhui, and the prevalence was 12.49% in women and 9.59% in men (P<0.05). The moderate, high and very high risk for CKD progression were 8.66%, 2.02% and 0.38%, respectively. Multivariate analysis showed that age (OR=1.03, 95%CI: 1.00-1.05), BMI (OR=1.05, 95%CI: 1.01-1.09), being woman (OR=1.38,95%CI: 1.22-1.55), hypertension (OR=2.50, 95%CI: 1.76-3.56), diabetes (OR=2.28, 95%CI: 1.51-3.43), dyslipidemia (OR=1.26, 95%CI: 1.11-1.43) and hyperuricemia (OR=2.16, 95%CI: 1.68-2.78) were risk factors for CKD. Conclusion: The prevalence of CKD in adults in Anhui was relatively high and age, gender, BMI, hypertension, diabetes, dyslipidemia and hyperuricemia were found to be associated with the prevalence of CKD. To prevent CKD and its complications, attention should be paid to the management of related risk factors, including overweight and obesity, hypertension, diabetes, dyslipidemia and hyperuricemia.

[Analysis of hemagglutinin-neuraminidase gene characteristics of human parainfluenza virus type 3 among children with acute respiratory tract infection in Qingdao city]

The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.

[Estimation of dietary salt intake in adult residents in Anhui province, 2019]

Objective: Based on the data of the baseline survey of hypertension and sodium intake monitoring in Anhui province in 2019, the salt intake in adult residents was estimated. Methods: Multi-stage stratified cluster random sampling was used to select participants aged 18-69 years, questionnaire survey and related measurements were conducted. Salt intake in participants with different characteristics were estimated with complex sample and linearization of Taylor series based on design and the correlation between salt intake and blood pressure, waist circumference and BMI were tested by linear regression. Results: A total of 1 500 participants were included. The overall salt intake was 9.14 g/d, which was 9.84 g/d in men and 8.47 g/d in women (P<0.05). The differences in salt intake across different subgroups were significant (P<0.05). Univariate linear regression analysis showed that salt intake was positively correlated with SBP, DBP, waist circumference and BMI (P<0.05), while multivariate linear regression analysis (adjusted for other factors) only showed a positive correlation between salt intake and BMI (β=0.053,95%CI: 0.028-0.078, P<0.05). Conclusion: The dietary salt intake in adult residents in Anhui was higher than WHO recommendation, suggesting that public health education need to be taken to reduce salt intake.

[In vitro study of non-thermal atmospheric plasma influencing the surface properties of dentin]

Objective: To study the influence of non-thermal atmospheric pressure plasma (NTAPP) on dentine surface temperature, wettability and morphology of collagen fibrils under different treatment condition. Methods: Helium was used as the operating gas at the flow rate of 3, 4, 5 L/min respectively. The plasma jet was operated at various input power of 8, 9, 10, 11 W. Thermal accumulation on human dentine surface (6 specimens per group, acquired from Department of Stomatology, The First Affiliated Hospital of Xi'an Medical University and Department of Stomatology, The Second Affiliated Hospital of Xi'an Medical University) of each group was measured continuously at 5 s intervals for 60 s by infrared thermography. Mean values were calculated and temperature curves were drawn. Dentine surface contact angles were measured after NTAPP treatment for 5, 10, 15, 20 s with gas flow rate and input power described above. The micro structure of the collagen fibrils of the negative control group (without NTAPP treatment) and NTAPP treatment groups (5 L/min gas flow rate, input power of 8, 9, 10, 11 W and treating time for 5, 10, 15, 20 s) was observed by field emission scanning electron microscopy (FE-SEM). All data were analyzed by SPSS 18.0. Results: Input power, gas flow and treatment time all showed significant influences on dentine surface temperature and wettability (P<0.01). Dentine temperature rose along with time. The greater input power was, the higher dentine temperature was. The greater gas flow rate was, the faster the temperature rose. Dentine surface temperature reached the highest point of (35.10±0.24) ℃ with NTAPP treatment for 60 s, at input power of 11 W and flow rate of 5 L/min. The contact angles of each experimental group decreased with time, and significant differences were found in the contact angles between the experimental groups and the negative control group (75.57°±1.45°). The contact angles showed a decreasing trend as the input power and the gas flow rate increased. The contact angles reached the lowest point of 13.19°±2.01° with NTAPP treatment for 20 s, at input power of 10 W and flow rate of 5 L/min. The FE-SEM results showed that, along with the increase of input power and extension of time, the demineralized collagen fibrils were destroyed in varying degrees. The collagen fibrils were curled, fractured, fused, and even disappeared. Conclusions: NTAPP could significantly increase the surface temperature, modify dentine wettability and alter the micro structure, which was significantly influenced by input power, gas flow rate and treating time.

[Analysis on the relationship between smoking status and the onset age of onset and the direct medical expenditure expenses of gastric cancer patients]

Objective: To investigate the relationship between smoking status and the onset age of stomach cancer patients and estimate the patients' direct medical cost burden of stomach cancer due to smoking in Anhui province. Methods: The information about the primary stomach cancer patients and their direct treatment expenditures in 10 cancer-registered areas in Anhui were collected in 2017. The association between smoking status and the age of onset of stomach cancer patients was analyzed by univariate regression and multivariate logistic regression models. The median and smoking-attributed risk method was used to describe the direct treatment expenditure of stomach cancer patients in Anhui due to smoking. Results: A total of 736 patients with stomach cancer were analyzed in this study. Univariate regression analysis showed that rural household registration (t=2.091, P=0.037), smoking (t=-2.357, P=0.001 9) and alcohol consumption (t=-2.036, P=0.042) were related to the age of onset of stomach cancer. After adjusting for gender, alcohol consumption, body mass index and household registration type, the risk of early stomach cancer in people who quitted smoking cessation was lower than that in smokers (OR=0.36, 95%CI: 0.17-0.75). The total direct medical cost burden of 736 newly diagnosed stomach cancer patients was 6.939 6 million RMB. The direct medical expenditure in stomach cancer patients who had smoking behavior was higher than that in stomach cancer patients who quitted smoking and never smoked. Conclusions: Smoking is one of the risk factors for the earlier onset of stomach cancer in Anhui. It is necessary to strengthen tobacco control to reduce the economic burden of patients with stomach cancer.

[Investigation on two family clusters of COVID-19 in a county of Baotou city in Inner Mongolia Autonomous Region]

Objective: To investigate the epidemiological characteristics and transmission chain of COVID-19 in two families, and to provide scientific evidence for effective prevention and control measures. Methods: Field epidemiological investigation was conducted for the COVID-19 cases occurred in two families and the close contacts in a county of Baotou city in Inner Mongolia Autonomous Region. Descriptive statistical analysis on epidemiological data was conducted. Results: The infection source of the COVID-19 cases in the two families was a man who had living history in Wuhan. After his return, his parents were infected by him. A few days later, the members of a neighbor family were found to be infected, and relatives of this family were also infected after dining together repeatedly. Finally, ten confirmed cases and three suspected cases of COVID-19 were detected in the two families. Conclusions: Human-to-human transmission of COVID-19 can occur not only in a family but also in neighborhoods. The cases in two families had close relationship, indicating the necessity to strengthen the health education about COVID-19 prevention and control and the management of groups at high risk to reduce the incidence of COVID-19 in families and neighborhoods.

[Epidemiological analysis on 1 052 cases of COVID-19 in epidemic clusters]

Objective: To understand the epidemiological characteristics of the cases of COVID-19 epidemic clusters, and explore the influence of family factors and social factors such as group activities on the spread of the disease. Methods: The data of cases of COVID-19 epidemic clusters from 19 January, 2020 to 25 February, 2020 were collected from the official platforms of 36 cities in 6 provinces in China. Descriptive statistical methods, χ(2) test and curve fitting were used to analyze the epidemiological characteristics of the clustered cases. Results: By 25 February, 2020, the data of 1 052 cases in 366 epidemic clusters were collected. In these clustered cases, 86.9%(914/1 050) occurred in families. Among the 1 046 cases with gender information, 513 were males (49.0%) and 533 were females (51.0%). The cases were mainly young adults between 18 and 59 years old, accounting for 68.5% (711/1 038). In the 366 epidemic clusters , the clusters in which the first confirmed cases with the history of sojourn in Wuhan or Hubei accounted for 47.0%(172/366). From 19 January to 3 February, 2020, the first confirmed cases with Wuhan or Hubei sojourn history accounted for 66.5%. From 4 to 25 February, the first confirmed cases who had Wuhan or Hubei sojourn history accounted for only 18.2%. The median of interval between the first generation case onset and the second generation case onset was 5 (2-8) days. The median of onset- diagnosis interval of the initial cases was 6 (3-9) days, and the median of onset-diagnosis interval of the secondary cases was 5 (3-8) days. Conclusions: Epidemic clusters of COVID-19 were common in many cities outside Wuhan and Hubei. Close contact in family was one of the main causes for the spread of household transmission of the virus. After 4 February, the epidemic clusters were mainly caused by the first generation or second generation cases in local areas, and the time for diagnosis became shorter.

[Analysis on epidemic situation and spatiotemporal changes of COVID-19 in Anhui]

We used the epidemic data of COVID-19 published on the official website of the municipal health commissions in Anhui province to map the spatiotemporal changes of confirmed cases, fit the epidemic situation by the population growth curve at different stages and analyze the epidemic situation in Anhui Province. It was found that the cumulative incidence of COVID-19 was 156/100 000 by February 18, 2020 and the trend of COVID-19 epidemic declined after February 7 with a change from J-shaped curve to S-shaped curve. As the reporting time of cases might be 3-5 days later than the actual onset time, the number of new cases in Anhui province actually began to decline around February 2 to February 4, 2020.

[A cross-sectional study on the prevalence and related factors of dyslipidemia among adults in Anhui province, in 2015]

Objective: Based on the data of chronic diseases and nutrition surveillance among Chinese adults in 2015, dyslipidemia and related factors were analyzed. Methods: Multi-stage stratified cluster random sampling was used to select participants who were aged 18 and over, with questionnaire survey and related measurements conducted. Prevalence rates of dyslipidemia among participants by different characteristics and influencing factors were analyzed, using the method of complex weighting and post-weighted stratification. Results: In all, 7 404 participants were included. The overall prevalence of dyslipidemia was 30.5% among the adults. The overall prevalence of dyslipidemia were 36.5% in males and 24.4% in females (P<0.05). The prevalence rates of hypercholesterolemia, hypertriglyceridemia, high LDL-C, and low HDL-C were 3.7%, 12.2%, 5.3%, and 19.4%, respectively. Results from the multivariate logistic regression model analysis showed that age (OR=1.009, 95%CI: 1.000-1.018), female (OR=0.501, 95%CI: 0.397-0.632), College degree or above (OR=1.728, 95%CI: 1.257-2.374), alcohol consumption 3 (OR=0.711, 95%CI: 0.536-0.943), central obesity (OR=1.868, 95%CI: 1.547-2.257), BMI (OR=1.141, 95%CI: 1.098-1.186), hypertension (OR=1.259, 95%CI: 1.077-1.473) and diabetes (OR=2.025, 95%CI: 1.446-2.835) were influencing factors on dyslipidemia. Conclusions: The prevalence of dyslipidemia seemed high among adults in Anhui. Risk factors should be closely monitored and under control, including those people with unhealthy lifestyles or being overweight, obesity, hypertensive and diabetic.

[A Meta-analysis of Pin1 gene polymorphism at -842 loci and cancer susceptibility]

Objective: Using Meta-analysis to evaluate the association between Pin1 gene polymorphism at -842 loci and cancer susceptibility. Methods: Pin1, polymorphism, tumor, variant and cancer as key words were used to systematically search for the case-control research on the association between the -842G/C polymorphisms of Pin1 and cancer susceptibility through China National Knowledge Infrastructure (CNKI), Wanfang Data, Embase and PubMed. The time of literatures was up to April 2(nd), 2019. Heterogeneity test, combined risk of cancer with the -842 C allele of Pin1, publication bias test and sensitivity analysis were performed by using Stata 12.0 software. Results: A total of 144 articles were retrieved. According to the inclusion criteria, a total of 11 articles were included (2 Chinese documents and 9 English documents). There were 5 667 cases and 6 120 controls in eligible articles. The heterozygous model showed that Pin1 (-842G/C) polymorphism was associated with cancer susceptibility, and the pooled OR (95%CI) value was 0.78 (0.61, 0.99). Subgroup analysis by cancer type suggested that the Pin1 (-842G/C) polymorphism could significantly decrease the incidence of breast cancer and lung cancer under the heterozygous model (GC vs GG), dominant model (GC+CC vs GG) and allele model (C vs G). The pooled OR (95%CI) values were 0.73 (0.58, 0.92), 0.71 (0.57, 0.89), and 0.73 (0.60, 0.89) in breast cancer and 0.64 (0.52, 0.78), 0.64 (0.53, 0.78), and 0.67 (0.55, 0.80) in lung cancer. The variant -842 C allele could significantly increase the risk of nasopharyngeal carcinoma under the homozygote model (CC vs GG) and recessive model (CC vs GG+GC). The pooled OR (95%CI) values were 2.22 (1.03-4.75) and 2.47 (1.16-5.26). No significant association was observed in squamous cell carcinoma. Conclusion: This Meta-analysis demonstrated that Pin1gene polymorphism at -842 was associated with cancer susceptibility.

[Electrocardiographic characteristics of idiopathic ventricular arrhythmias originating from the tricuspid annulus regions]

Object: To explore the electrocardiographic characteristics of ventricular arrhythmias (VAs) originating from tricuspid annulus region. Methods: Present study included 169 consecutive patients undergoing catheter ablation of VAs from tricuspid annulus origin in our department from August 2007 to September 2016. Based on the origin sites, the patients were divided into two subgroups, the free wall group (81 cases) and septal wall group (88 cases). Based on the location, patients in the free wall group were classified into anterolateral (22 cases), lateral (26 cases) and posterolateral (33 cases) subgroups. Patients in the septal group were classified into anteroseptal (10 cases), midseptal (71 cases) and posteroseptal (7 cases) subgroups. We analyzed the electrocardiographic features of these patients and in 87 patients with PVCs/VT originating from right ventricular outflow tract. Results: (1) A positive R wave inⅠ, aVL, V(5)-V(6) leads were found among most of patients, only few cases originating from tricuspid annulus anteroseptum group and tricuspid annulus anterolateral group demonstrated qr or qs pattern in aVL lead. 97.53% (79/81) patients demonstrated rS pattern in V(1)-V(3) leads with VAs originating from tricuspid annulus free wall, and 9/10 patients demonstrated rS pattern in V(1) lead with VAs originating from anteroseptum, and 97.44% (76/78) patients demonstrated QS pattern in V(1) lead with VAs originating from midseptum and posteroseptum. Precordial lead transition zone was on or behind V(3) for tricuspid annulus free wall group (96.3%, 78/81), but in front of V(3) for tricuspid annulus septum wall group (47.73%, 42/88) (P<0.01). The S wave's amplitude smaller than-1.81 mV in lead V(2) can be used as a cutoff value to identify if PVC/VT is originating from free wall or septum of TA. R wave in inferior wall leads was found among 98.85% (86/87) patients with PVCs/VT originating from right ventricular outflow tract. Conclusion: A positive R wave in Ⅰ, aVL, V(5)-V(6) leads was found among most of patients with idiopathic ventricular arrhythmias originating from the tricuspid annulus regions, but VAs originating from different portions of tricuspid annulus area have distinct electrocardiographic characteristics.

[Clinical significance of syndecan-1 and syndecan-2 expression in gallbladder squamous cell/adenosquamous carcinoma and adenocarcinoma]

Objective: To investigate the expression of syndecan-1 and syndecan-2 and their clinicopathological significance in patients with gallbladder squamous cell (SC)/adenosquamous carcinoma (ASC) and adenocarcinoma (AC). Methods: A total of 126 patients with SC/ASC (n=46) and AC (n=80) were included in this study. The expression levels of syndecan-1 and syndecan-2 were detected by Envison™ immunohistochemistry assay. The clinical and prognostic significance of syndecan-1 and syndecan-2 were analyzed. Results: In the 46 SC/ASC samples, syndecan-1 and syndecan-2 were positively expressed in 29 (63.0%) and 28 (60.9%) tumor tissues, respectively. (Positive expression was defined based on the staining in the component of squamous cell carcinoma. That is to say, the tissue which adenocarcinoma part was positively stained, but squamous cell carcinoma part was negatively stained is also regarded as negative.) In the 80 AC samples, 47 (58.8%) cases showed syndecan-1 positive expression, and 51 (63.8%) showed syndecan-2 positive expression. There was no significant difference in the positive rates of syndecan-1 and syndecan-2 between SC/ASC and AC groups (P>0.05 for all). The levels of syndecan-1 and syndecan-2 were associated with tumor size, TNM staging, lymph node metastasis, invasion of adjacent tissue, and surgical procedures in SC/ASC patients (P<0.05 for all). However, their expression was associated with tumor differentiation, tumor size, TNM staging, lymph node metastasis, invasion of adjacent tissue, and surgical procedures in AC patients (P<0.05 for all). The Kaplan-Meier survival analysis of SC/ASC and AC patients revealed that the average survival time for patients with positive syndecan-1 and syndecan-2 expression was significantly shorter than that of those with negative expression (P<0.01 for all). Cox multivariate analysis indicated that syndecan-1 and syndecan-2 expression were independent unfavorable prognostic factors for SC/ASC and AC patients (P<0.05 for all). Conclusion: The syndecan-1 and syndecan-2 expression are associated with the tumor progression and poor prognosis in patients with gallbladder SC/ASC and AC.

[Relationship and clinicopathological significance of Numb and epithelial-mesenchymal transition related proteins in human pancreatic cancer]

Objective: To study the relationship and clinicopathological significance of Numb and epithelial-mesenchymal transition related proteins in human pancreatic cancer(PC). Methods: Sixty-three cases of pancreatic cancer tissues were obtained from department of gastrointestinal surgery in the First Hospital of China Medical University from January 2005 to December 2012, all samples were histopathologically proved to be adenocarcinoma. The expressions of Numb, E-cadherin and Vimentin proteins in 63 cases of pancreatic cancer specimens were detected by immunohistochemistry. Western blot and real-time PCR were used to examine the protein and mRNA levels in two pancreatic cancer cell lines. Pearson and chi-squared tests were used to analyze the relationship and clinicopathological characters with PC patients. Kaplan-Meier curve and log rank test were used to estimate the difference of PC patients' survival. Results: The positive rates of Numb, E-cadherin and Vimentin expressions were 46.0%, 41.3% and 28.6%, respectively. Numb expression was negatively associated with tumor size, differentiation and UICC stage(r=-0.310, P=0.010; r=-0.359, P=0.004; r=-0.228, P=0.020), while E-cadherin expression was negatively related with tumor differentiation(r=-0.316, P=0.012). In contrast, Vimentin expression was positively related with pancreatic cancer differentiation and lymph metastasis(r=0.264, P=0.036; r=0.274, P=0.030). Correlation analysis showed Numb had a positive association with E-cad expression(r=0.325, P=0.010), but had no association with Vimentin. Moreover, patients with co-expression of Numb and E-cadherin had a significantly better overall survival in Kaplan-Meier univariate analysis(P=0.046). Immunoblotting and real-time PCR showed that high Numb protein and mRNA levels in BxPC-3 cells were followed with high E-cadherin and low Vimentin expressions, whereas low Numb protein and mRNA levels in PANC-1 cells were followed with low E-cadherin and high Vimentin expressions, respectively. Conclusions: Numb has a positive relationship with E-cadherin in both pancreatic cancer tissues and cells.The interaction between them might participate in the initiation and development of epithelial-mesenchymal transition in pancreatic cancer.

Characterization of submicron particles during biomass burning and coal combustion periods in Beijing, China

An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed along with other observation instruments to measure the characteristics of PM1 (particulate matter with a vacuum aerodynamic diameter of ≤1μm) during the biomass burning period (October 1 to 27; BBP) and the coal combustion period (December 10 to 31; CCP) in Beijing in 2014. The average PM1 mass concentrations during the BBP and CCP were 82.3 and 37.5μgm(-3), respectively. Nitrate, ammonium and other pollutants emitted by the burning processes, especially coal combustion, increased significantly in association with increased pollution levels. Positive matrix factorization (PMF) was applied to a unified high-resolution mass spectra database of organic species with NO(+) and NO2(+) ions to discover the relationships between organic and inorganic species. One inorganic factor was identified in both periods, and another five and four distinct organic factors were identified in the BBP and CCP, respectively. Secondary organic aerosols (SOAs) accounted for 55% of the total organic aerosols (OAs) during the BBP, which is higher than the proportion during the CCP (oxygenated OA, 40%). The organic nitrate and inorganic nitrate were first successfully separated through the PMF analysis based on the HR-ToF-AMS observations in Beijing, and organic nitrate components accounted for 21% and 18% of the total nitrate mass during the BBP and CCP, respectively. Although the PM1 mass concentration during the CCP was much lower than in the BBP, the average concentration of polycyclic aromatic hydrocarbons (PAHs) during the CCP (107.3±171.6ngm(-3)) was ~5 times higher than that in the BBP (21.9±21.7ngm(-3)).

[Trend and characteristics of fall in elderly adults based on data from national injury surveillance sentinel hospitals in Anhui province, 2006-2014]

OBJECTIVE

To understand the incidence pattern of fall among older adults in Anhui province during 2006-2014, and provide scientific basis for intervention strategies and decision-making.

METHODS

The incidence data of fall in elderly adults from 6 sentinel hospitals in 2 national injury surveillance areas in Anhui province between 2006 and 2014 were collected for this descriptive epidemiological analysis of the overall incidence trend, demographic characteristics, case distribution and clinical characteristics of fall cases in the elderly.

RESULTS

The fall case number, the proportions of fall cases to injury cases and to overall fall cases in the elderly all increased from 2006 to 2014. The fall was the first cause of the elderly injury during the past 9 years. The sex ratio was 0.74 and the cases in males decreased with age. In both males and females, the cases in retirees and the jobless accounted for the highest proportions. The annual incidence peak was during August to October, and two daily incidence peaks were during 9 am-11 am and 16 pm-18 pm. The elderly falls mainly occurred at home(62.07%), and more females were affected than males(70.27% vs. 50.97%). Leisure activity and homework related falls accounted for 49.18% and 28.67% respectively, and more housework related falls occurred in females than in males. Contusion/abrasion was the first injury caused by fall in males(42.63%)and fracture was the first injury caused by fall in females(47.27%). Head was the first injury site in males(38.04%)and leg was the first injury site in females(29.29%). Most injuries caused by fall were mild(55.12%)and moderate(41.84%)in severity, but the proportions of moderate and severe cases increased gradually with age.

CONCLUSION

Fall in the elderly has become a public health problem. It is necessary to take targeted prevention and control measures according to the gender and age distributions of the fall in the elderly.

PKA phosphorylation reshapes the pharmacological kinetics of BmK AS, a unique site-4 sodium channel-specific modulator

Although modulation of the activity of voltage-gated sodium channels (VGSCs) by protein kinase A (PKA) phosphorylation has been investigated in multiple preparations, the pharmacological sensitivity of VGSCs to scorpion toxins after PKA phosphorylation has rarely been approached. In this study, the effects of BmK AS, a sodium channel-specific modulator from Chinese scorpion Buthus martensi Karsch, on the voltage-dependent activation and inactivation of Nav1.2 were examined before and after PKA activation. After PKA phosphorylation, the pattern of dose-dependent modulation of BmK AS, on both Nav1.2α and Nav1.2 (α + β1) was reshaped. Meanwhile, the shifts in voltage-dependency of activation and inactivation induced by BmK AS were attenuated. The results suggested that PKA might play a role in different patterns how β-like toxins such as BmK AS modulate gating properties and peak currents of VGSCs.

The prevalence of family childhood adversities and their association with first onset of DSM-IV disorders in metropolitan China

BACKGROUND

The prevalence of family childhood adversities (FCAs) and their joint effects on the first onset of subsequent mental disorders throughout the life course are rarely examined, especially in Asian communities.

METHOD

Face-to-face household interviews of 5201 people aged 18-70 years in Beijing and Shanghai were conducted by a multi-stage household probability sampling method. The first onsets of four broad groups of mental disorders and six categories of FCAs were assessed using The World Mental Health Composite International Diagnostic Interview (WMH-CIDI). Joint effects of FCAs were analyzed by the best fitting of several competitive multivariate models.

RESULTS

FCAs were highly prevalent and inter-correlated. Half of them were in a family-dysfunction cluster. The best-fitting model included each of six types of FCA (with family-dysfunction FCAs being the strongest predictors), number of family-dysfunction FCAs, and number of other FCAs. Family-dysfunction FCAs had a significant subadditive association with subsequent disorders. Little specificity was found for the effects of particular FCAs with particular disorders. Predictive effects of FCAs reached the highest in ages 13-24 compared to ages 4-12 and ≥ 25. Estimates of population-attributable risk proportions indicated that all FCAs together explained 38.5% of all first-onset disorders.

CONCLUSIONS

Chinese children were exposed to a broad spectrum of inter-related FCAs, as found in Western countries. FCAs related to family dysfunction were especially associated with subsequent mental disorders. Biological and/or environmental factors that mediate these long-term effects should be studied in prospective research on broad groups of FCAs.

The epidemiology of depression in metropolitan China

BACKGROUND

Previous surveys on depression in China focused on prevalence estimates without providing a detailed epidemiological profile.

METHOD

Face-to-face household interviews were conducted with a multi-stage household probability sample of 2633 adults (age > or = 18 years) in Beijing and 2568 in Shanghai between November 2001 and February 2002. The World Health Organization Composite International Diagnostic Interview (CIDI) was used to assess major depressive episode (MDE) according to Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria.

RESULTS

The lifetime prevalence and 1-year prevalence estimates of DSM-IV/CIDI MDE were 3.6% [95% confidence interval (CI) 2.8-4.4%] and 1.8% (95% CI 1.2-2.4%) respectively. No significant gender difference was found in these estimates. Respondents born in 1967 or later were at elevated lifetime risk compared with respondents born in earlier cohorts. The mean age of onset was 30.3 years. Among those reporting 1-year MDE, 15.7, 51.8, 25.3 and 6.4% reported mild, moderate, severe and very severe symptoms respectively; 4.8, 2.6 and 3.2% reported suicidal ideation, plans, and recent attempts in the same year respectively. Respondents with 1-year MDE reported a mean of 27.5 days out of role owing to their depression in the year before interview. Significant co-morbidity was found between MDE and other mental disorders [odds ratio (OR) 22.0] and chronic physical disorders (OR 3.2). Only 22.7% of respondents with 1-year MDE sought treatment.

CONCLUSIONS

The low prevalence and insignificant gender difference, but not patterns of onset, course, co-morbidity, and impairment, distinguish the epidemiological profile of MDE in metropolitan China from those in other countries.

Lifetime prevalence of suicide ideation, plan, and attempt in metropolitan China

OBJECTIVE

This is the first community-based epidemiological study examining the prevalence of suicidal behaviors, their transitional pathways, and their relationship with mental disorders in metropolitan China.

METHOD

Suicidal behaviors, including ideation, plans, and attempts were assessed by face-to-face household interviews among 5201 respondents in Beijing and Shanghai in 2001-2002. Lifetime prevalence and risk factors were examined using multivariate discrete-time survival models.

RESULTS

The lifetime prevalence estimates of suicidal ideation, plans, and attempts were 3.1%, 0.9%, and 1.0% respectively. Among suicide ideators, the conditional probability of ever making a plan and an attempt was 29.5% and 32.3% respectively. Progression from ideation to plan and attempt was the highest during the first year after onset. Suicide attempt was predicted by young adulthood, being unmarried, recent onset of ideation and plan, and the presence of mental disorders, especially mood disorder.

CONCLUSION

Suicidal behaviors in metropolitan China exhibit a low prevalence and an epidemiological profile resembling that found in Western countries.

Delay in initial treatment contact after first onset of mental disorders in metropolitan China

OBJECTIVE

There has been no community-based research on treatment delay among people with mental disorders in China. This study examines lifetime treatment and treatment delay in metropolitan China.

METHOD

A multi-stage probability survey of 5201 respondents was administered in Beijing and Shanghai. Age of first treatment contact after onset of each of the three lifetime DSM-IV/CIDI disorder classes was compared with retrospective information on age of disorder onset. Length and predictors of treatment delay were examined using survival analysis.

RESULTS

Survival curves estimate that 44.7%, 25.7%, and 7.9% of people with anxiety, substance, and mood disorders, respectively, will ever make treatment contact. Delays in first treatment contact of anxiety (21 years) and substance (17 years) disorders are longer than that of mood disorders (1 year). These delays are largely unrelated to sociodemographic variables.

CONCLUSION

Failure to receive treatment is a pervasive phenomenon among people with mental disorders in metropolitan China.

Facile synthesis of optically pure (S)-3-p-hydroxyphenyllactic acid derivatives

Optically pure (S)-3-p-hydroxyphenyllactic acid derivatives are important intermediates of peroxisome proliferator-activated receptor alpha/gamma dual agonists and heteropeptides. Many efforts have been made for synthesis of those intermediates, but there exist some flaws yet. We observed that dielectric constants of organic solvents drastically affected diazotization of O-benzyl-L-tyrosine. Optically pure (S)-3-p-benzyloxyphenyllactic acid was obtained by simple recrystallization when DMF or DMSO of higher dielectric constant was used as a co-solvent in diazotization of O-benzyl-L-tyrosine. It was easily turned into various optically pure (S)-3-p-hydroxyphenyllactic acid derivatives.

Metal binding affinity and structural properties of an isolated EF-loop in a scaffold protein

To establish an approach to obtain the site-specific calcium binding affinity of EF-hand proteins, we have successfully designed a series of model proteins, each containing the EF-hand calcium-binding loop 3 of calmodulin, but with increasing numbers of Gly residues linking the loop to domain 1 of CD2. Structural analyses, using different spectroscopic methods, have shown that the host protein is able to retain its native structure after insertion of the 12-residue calcium-binding loop and retains a native thermal stability and thermal unfolding behavior. In addition, calcium binding to the engineered CD2 variants does not result in a significant change from native CD2 conformation. The CD2 variant with two Gly linkers has been shown to have the strongest metal binding affinity to Ca(II) and La(III). These experimental results are consistent with our molecular modeling studies, which suggest that this protein with the engineered EF-loop has a calmodulin-like calcium binding geometry and backbone conformation. The addition of two Gly linkers increases the flexibility of the inserted EF-loop 3 from calmodulin, which is essential for the proper binding of metal ions.

[Determination of rate constants of gas-phase reactions of alpha-pinene and beta-pinene with ozone]

alpha-pinene and beta-pinene are the most dominating species among natural terpenes. Terpenes are mainly emitted from forest trees, flowers and grass. In the lower troposphere terpenes can react fast with OH radical, ozone, NO3 radical and ground state oxygen atom. These reactions may contribute to the occurring of aerosols, peroxides (hydrogen peroxide and organic peroxide), carbon cycle (mainly CO), acid rain (organic acids, NO3- and SO4(2-), ozone and active radicals such as OH radical. Reactions with ozone occur both in the daytime and in the night. The study in this field in China began in the late 1980. The main work focus on the source emission and the experimental simulation has just started. It is most of our group's work. In this paper preliminary experimental simulation of the gas-phase reactions of alpha-pinene and beta-pinene with ozone were carried out in the quartz chamber. The rate constants of these reactions were measured using long-path Fourier transform infra-red combined with relative rate constant method. And the rate constants for the gas-phase reactions of alpha-pinene, beta-pinene with ozone were determined as 2.83 x 10(17) cm3.molecule-1.s-1 and 1.48 x 10(17) cm3.molecule-1.s-1 at 1.0 x 10(5) Pa and 296 +/- 3 K. The results are quite similar to the data from Atkinson group. No cyclohexane was added to the reaction system during the measurement to restrain the formation of OH radical. The formation of OH radical could not be quantified, so that the effect of subsidiary reactions induced by OH radical has not been calculated. In the later simulation study and model this effect should be considered.

Identification of a locus for disseminated superficial actinic porokeratosis at chromosome 12q23.2-24.1

Disseminated superficial actinic porokeratosis is an autosomal dominant cutaneous disorder characterized by many uniformly small, minimal, annular, anhidrotic, and keratotic lesions. The genetic basis for this disease is unknown. Using a genomewide search in a large Chinese family, we identified a locus at chromosome 12q23.2-24. 1 responsible for disseminated superficial actinic porokeratosis. The fine mapping study indicates that the disseminated superficial actinic porokeratosis gene is located within a 9.6 cM region between markers D12S1727 and D12S1605, with a maximum two-point LOD score of 20.53 (theta = 0.00) at D12S78. This is the first locus identified for a genetic disease where the major phenotype is porokeratosis. The study provides a map location for isolation of a gene causing disseminated superficial actinic porokeratosis.

Detection of a novel ATP-dependent cross-linked protein at the 5' splice site-U1 small nuclear RNA duplex by methylene blue-mediated photo-cross-linking

Assembly of spliceosomes involves a number of sequential steps in which small nuclear ribonucleoprotein particles (snRNPs) and some non-snRNP proteins recognize the splice site sequences and undergo various conformational rearrangements. A number of important intermolecular RNA-RNA duplexes are formed transiently during the process of splice site recognition. Various steps in the assembly pathway are dependent upon ATP hydrolysis, either for protein phosphorylation or for the activity of helicases, which may modulate the RNA structures. Major efforts have been made to identify proteins that interact with specific regions of the pre-mRNA during the stages of spliceosome assembly and catalysis by site-specific UV cross-linking. However, UV cross-linking is often inefficient for the detection of proteins that interact with base-paired RNA. Here we have used the complementary approach of methylene blue-mediated photo-cross-linking to detect specifically proteins that interact with the duplexes formed between pre-mRNA and small nuclear RNA (snRNA). We have detected a novel cross-link between a 65-kDa protein (p65) and the 5' splice site. A range of data suggest that p65 cross-links to the transient duplex formed by U1 snRNA and the 5' splice site. Moreover, although p65 cross-linking requires only a 5' splice site within the pre-mRNA, it also requires ATP hydrolysis, suggesting that its detection reflects a very early ATP-dependent event during splicing.

Crosslinking of the U5 snRNP-specific 116-kDa protein to RNA hairpins that block step 2 of splicing

Step 2 of pre-mRNA splicing has characteristics that are suggestive of a 5' to 3' scanning process from the branch point to locate the 3' splice site. Specifically, the 3' splice site is almost always at the first AG downstream of the branch point even when the two elements are separated by hundreds of nucleotides. Insertion of new AGs between the branch and 3' splice site, or mutation of the wild-type 3' splice site, usually results in use of the new first AG as the 3' splice site. Finally, insertion of stable secondary structure between the branch point and 3' splice site, but distant from both elements, results in a block to step 2. We have sought to complement this circumstantial evidence by detecting physical contacts between the spliceosome and the RNA substrate in regions that are not themselves important for splicing, other than that they lie between the branch point/polypyrimidine tract and the 3' splice site. We have blocked step 2 of splicing by insertion of hairpin structures between the branch point and 3' splice site and applied methylene blue-mediated crosslinking, which is specific for protein-dsRNA interactions. Using this approach, we have detected a 116-kDa crosslinked protein that appears after step 1 of splicing with all transcripts containing a hairpin downstream of the branch point. The protein was identified as the 116-kDa U5 snRNP protein, which is a GTP-binding protein involved in step 2 of splicing. The crosslinking characteristics of U5 p116 are consistent with it having a role in locating the 3' splice site AG prior to step 2 of splicing.

Selective DNA binding of (N-alkylamine)-substituted naphthalene imides and diimides to G+C-rich DNA

Alkylamine-substituted naphthalene imides and diimides bind DNA by intercalation and have applications as anticancer agents. The unique structures of these imides in which two adjacent carbonyl groups lie coplanar to an extended aromatic ring system allow the possibility of sequence-selective interactions between the intercalated chromophore and guanine amino groups situated in the DNA minor groove. The binding affinities of N-[3-(dimethylamino)propyl amine]-1,8-naphthalenedicarboxylic imide (N-DMPrNI) and N,N'-bis [3,3'-(dimethylamino)propylamine]-naphthalene-1,4,5,8-tetracarboxylic diimide (N-BDMPrNDI) for natural DNAs of differing base composition were determined spectroscopically and by equilibrium dialysis. In agreement with the above proposition, binding studies indicated that both the naphthalene imide and diimide strongly prefer to intercalate into steps containing at least one G:C base pair. The dependencies of association constants on DNA base composition are consistent with a requirement for one G:C pair in the binding site of the monomide, and two G:C pairs in binding sites of the diimide. These selectivities are comparable to or exceed that of actinomycin D, a classic G:C-selective drug. Protection footprinting with DNase I confirmed that the naphthalene monoiimide (N-DMPrNI) prefers to bind adjacent to G:C base pairs, with a most consistent preference for "mixed" steps containing both a G:C and an A:T pair, excepting GA:TC. Several 5'-CG-3' steps were also good binding sites as indicated by nuclease protection, but few GC:GC or GG:CC steps were protected. The naphthalene diimide inhibited DNase I digestion, but did not yield a footprint. The base recognition ability and versatile chemistry make naphthalene imides and diimides attractive building blocks for design of highly sequence-specific, DNA-directed drug candidates including conjugated oligonucleotides or oligopeptides.

Detection of double-stranded RNA-protein interactions by methylene blue-mediated photo-crosslinking

Double-stranded(ds) RNA-binding proteins have diverse functions in the cell. An obstacle to investigating the interactions between these proteins and dsRNA is the relative inefficiency of traditional UV-crosslinking methods for extended regions of dsRNA. We have therefore developed an alternative procedure for RNA-protein photo-crosslinking that efficiently induces RNA-protein crosslinks in double-stranded regions of RNA. We show that dsRNA-protein crosslinks can be induced by visible light in the presence of the dye methylene blue, which most likely mediates crosslinking by intercalating in the dsRNA helix. A recombinant dsRNA binding domain from the Drosophila staufen protein and human protein kinase R were crosslinked by UV or methylene blue to a series of dsRNAs. In each case, the degree of crosslinking was greater with methylene blue, particularly with RNAs with few single-stranded loops. Methylene blue-mediated crosslinking therefore complements and extends the existing repertoire of crosslinking methods for detecting RNA-protein interactions.

N,N'-bis[3,3'-(dimethylamino)propylamine]-3,4,9, 10-perylenetetracarboxylic diimide, a dicationic perylene dye for rapid precipitation and quantitation of trace amounts of DNA

A novel dicationic dye with a polycyclic aromatic perylene core and flexible cationic side chains- N,N'-bis[3, 3'-(dimethylamino)propylamine]-3,4,9,10-perylenetetracarboxylic diimide-termed "DAPER," was synthesized and characterized. The dye appears to exist in a highly stacked form in aqueous solution. DAPER precipitates extremely low concentrations of DNA very rapidly, efficiently, and with a stoichiometry of one tightly bound dye per DNA base pair, corresponding to a neutral complex. Precipitation may occur due to side-by-side association between the polyanionic DNA helix and polycationic dye stacks. DNA precipitation by DAPER is less sensitive to DNA concentration and length, and prevailing salt concentrations, than precipitation with ethanol or propanol. DAPER can be quantitatively extracted from DNA into a standard phenol:chloroform mixture under slightly alkaline conditions. The recovered DNA is suitable for treatment with enzymes typically used in DNA sequencing procedures. The amount of DNA precipitated is accurately determined by visible absorption or fluorescence spectroscopic analyses of the phenol:chloroform extracts. Several samples of DNA can be precipitated, recovered, and quantitated in about 1 h using standard microscale procedures and equipment. The unique qualities of DAPER provide the basis for a very sensitive, rapid, and versatile method for simultaneous precipitation and quantitation of microgram and submicrogram amounts of DNA.

Experimental study of chuanxiong on cerebrovascular hemodynamic parameters

In the experimental rabbit arteriosclerosis, the change of the cerebrovascular hemodynamic parameters (CVHP) and the effect of Chuanxiong (CX) on CVHP were observed. In arteriosclerosis group (AS group), the mean flow (Qmean), mean velocity (Vmean), maximal velocity (Vmax) and minimal velocity (Vmin) of the carotid blood flow and cerebrovascular compliance for zero pressure (CO) were significantly decreased (P < 0.05, 0.01), but the values of cerebrovascular peripheral resistance (R) and characteristic impedance (Zc) were significantly increased (P < 0.05 and 0.01), and the value of R showed significant positive correlation with the extent of carotid lesions (P < 0.01). All indexes of CVHP of the Chuanxiong group (CX group) were close to and had no significant difference from those of the normal group (N group) but Qmean, Vmean, Vmin, CO and R were significantly better than those of the AS group (P < 0.05, 0.01). These results showed that CX can effectively improve cerebrovascular hemodynamics.

Investigation of the mechanism underlying the inhibitory effect of heterologous ras genes in plant cells

The ras genes from yeast and mammalian cells were fused to plant expression promoters, and introduced into plant cells via Agrobacterium, to study their effect on cell growth and development. All introduced ras genes had a strong inhibitory effect on callus and shoot regeneration from plant tissues. This is consistent with earlier findings that heterologous ras genes were highly lethal to protoplasts following direct DNA uptake. These effects could not be reversed by increasing exogenous or endogenous cytokinin levels. These effects were also independent of the v-Ha-ras mutations in functionally important regions of Ras proteins such as effector-binding and membrane-binding sites. Similarly, co-transformation with the genes encoding the Ras-negative regulators, GTPase-activating protein and neurofibromin did not affect the ras inhibitory effect, indicating that the mechanism of ras inhibition of plant cells is not related to normal ras cellular functions. This conclusion was supported by further studies in which ras gene expression was modified using various promoters and antisense constructs. The introduced ras sequences remained fully inhibitory regardless of which promoters (inducible or tissue-specific) or which orientations (sense or antisense) were tested. This strongly suggests that the ras DNA sequence itself, rather than the Ras protein or ras mRNA, is directly involved in the inhibitory effect. The mechanism underlying this novel phenomenon remains unknown. Introduced ras genes may inhibit plant cell growth by inducing co-suppression of unknown endogenous ras or ras-related genes, thereby leading to the arrest of cell growth.

Structural alterations in desferrioxamine compatible with iron clearance in animals

The design, synthesis, and biological evaluation of amideless desferrioxamine analogues are described. The design concept is predicated on the idea that a low molecular weight desferrioxamine analogue would represent a better pharmacophore from which to construct an orally effective or more efficient trihydroxamate than the parent chelator. The study demonstrates that (1) the monohydroxamate units of desferrioxamine must be linked to promote iron clearance, (2) the N-propanoyl-N-pentyl fragments of desferrioxamine can be replaced with smaller, e.g., C-5, methylene units without compromising the analogue's iron-clearing properties, and (3) a delicate balance exists between the molecule's iron-clearing efficiency and its lipophilicity.

Single amino acid substitution alters T cell determinant selection during antigen processing of Staphylococcus aureus nuclease

The effect of amino acid residues outside of T cell determinant regions of Staphylococcus aureus nuclease (Nase) on the activation of T cell hybridomas has been investigated. T cell hybridomas derived from BALB/c mice immunized with Nase were screened against a nested set of overlapping synthetic peptides spanning the entire Nase molecule. Five regions of Nase, encompassing residues 1 to 20, 21 to 40, 61 to 80, 101 to 120, and 112 to 130, were found to be the T cell determinants. Region 61 to 80 is the immunodominant site. Mutants of Nase with a single amino acid substitution outside the defined T cell determinants were tested for their ability to stimulate the T cell hybridomas. The substitution of arginine for glutamic acid at residue 43 markedly reduces the antigenic potency of the protein for I-Ed restricted T cell hybridomas, which recognize Nase peptides comprised of residues 21 to 40 (p21-40) or 112 to 130 (p112-130). In contrast, the stimulatory capacity of this mutant for I-Ad restricted T cell hybridomas remains unchanged. Our results suggest that selective regulation of an immune response may be achieved by appropriately mutagenizing protein Ag.

Single amino acid substitution alters T cell determinant selection during antigen processing of Staphylococcus aureus nuclease

The effect of amino acid residues outside of T cell determinant regions of Staphylococcus aureus nuclease (Nase) on the activation of T cell hybridomas has been investigated. T cell hybridomas derived from BALB/c mice immunized with Nase were screened against a nested set of overlapping synthetic peptides spanning the entire Nase molecule. Five regions of Nase, encompassing residues 1 to 20, 21 to 40, 61 to 80, 101 to 120, and 112 to 130, were found to be the T cell determinants. Region 61 to 80 is the immunodominant site. Mutants of Nase with a single amino acid substitution outside the defined T cell determinants were tested for their ability to stimulate the T cell hybridomas. The substitution of arginine for glutamic acid at residue 43 markedly reduces the antigenic potency of the protein for I-Ed restricted T cell hybridomas, which recognize Nase peptides comprised of residues 21 to 40 (p21-40) or 112 to 130 (p112-130). In contrast, the stimulatory capacity of this mutant for I-Ad restricted T cell hybridomas remains unchanged. Our results suggest that selective regulation of an immune response may be achieved by appropriately mutagenizing protein Ag.

The influence of N2-O2 and He-O2 saturation diving on electroencephalogram of human bodies

This paper reports the changes of the EEG of human bodies during saturation exposure at different depths to different mixed gases. The results of the research show that the most obvious on EEG was the appearance of diffused slow waves, usually theta waves of 4-7 times/s, and delta waves of 2-3 times/s within individual subjects. The EEG changes at 50 m were more obvious than those at 36.5 m. With the prolonging of time under high pressure, the EEG had some improvements, for instance, the slow waves decreased and the alpha waves increased. There was a certain relationship between these changes and the symptoms which appeared in the human body. The chief factor of the EEG changes is due to the effect of nitrogen narcosis during the oxygen-nitrogen diving experiment. In addition, carbon dioxide retention under the high pressure is also a factor of the EEG changes, because repeated inhaling of CO2-dense mixtures could aggravate the EEG changes and the reduction of carbon dioxide in humans by hyperventilation could improve abnormal EEGs. The main changes of the EEG during the helium-oxygen exposure at 302 m were the increase of theta waves, and even of delta waves, the decrease in alpha rhythm and the decline of amplitude of alpha waves. Increased theta index and decreased alpha index could be seen at the depth of 302 m. Under any of the above-mentioned pressure conditions when slow waves characteristic of abnormal changes appeared in the EEGs, the EEGs could be temporarily improved by photic stimulation, i.e. slow waves disappeared and alpha waves reappeared. When photic stimulation was over, alpha waves disappeared and slow waves reappeared. It was indicated that abnormal changes of the EEG under high pressure were a kind of temporary and reversible changes of the brain function.

Aortic compliance in human hypertension

Aortic compliance in normotensive and hypertensive Chinese subjects undergoing diagnostic cardiac catheterization was compared by using a newly described method that allows for determination of the pressure dependence of compliance if one assumes a value for the exponential coefficient of the pressure-volume relation of the large arteries. Under baseline conditions in the normotensive and hypertensive groups at mean aortic pressures of 96.3 and 128.6 mm Hg, aortic compliance averaged 1.47 and 0.80 ml/mm Hg, respectively. Compliance in the hypertensive group at a diastolic pressure of 99.4 mm Hg (which was nearly equal to the mean normotensive pressure) was 1.072 ml/mm Hg--still significantly lower than in the normotensive group. During nitroprusside infusion, however, the compliances in the hypertensive group increased to levels equal to or greater those in the normotensive group. Thus, these data confirm that aortic compliance is lower in hypertensive than in normotensive humans. They further demonstrate that the lower compliance cannot be attributed entirely to the elevated blood pressure, suggesting that excess smooth muscle tone may be partly responsible.

Estimating arterial resistance and compliance during transient conditions in humans

Almost all existing methods for estimating hemodynamic parameters are valid only during steady-state conditions. There is often a need, however, for estimating peripheral resistance and total arterial compliance during beat-to-beat transients such as during atrial fibrillation. During such transients the pressure at the onset and end of a cardiac cycle usually differ. This pressure difference necessitates a modification of usual methods used for estimating these hemodynamic parameters. In this paper we formulate a method for estimating resistance and total arterial compliance during such beat-to-beat transients. For simplicity the expressions are derived for a two-element windkessel model of the circulation. The method is a generalization of one we previously proposed. Rather than using parameter estimation techniques or having to assume a monoexponential pressure decay during diastole, our method uses the areas under the systolic and diastolic portions of the aortic pressure versus time tracing to obtain explicit expressions for compliance; both for the case where it is constant and when it is assumed to be nonlinear (exponential) function of pressure. Aortic pressure and flow data from patients undergoing cardiac catheterization are employed to illustrate the method. Results illustrate the quantitative difference between uncorrected and corrected estimates of both resistance and compliance as a function of the pressure difference between the onset and end of each beat. The uncorrected parameters were found to be linearly and highly correlated with these pressure differences. Regressions of pressure difference against normalized values revealed that the pooled data for all patients defined a single relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

Impedance of arterial system simulated by viscoelastic t tubes terminated in windkessels

An improved asymmetric t-tube model of the arterial system is proposed. The model consists of two viscoelastic tubes of differing lengths, each terminated in a modified windkessel with inductance as well as resistance and compliance. Equations for calculating the input impedance of this model are presented. Using typical data from the literature, the model predicts a more realistic impedance modulus and phase than previous models of the circulation. Parametric analysis shows that when peripheral compliances are altered, sharp peaks in the very low frequency portions of the impedance spectra are produced, whereas alterations of either the characteristic impedances or inductances of the terminations have little effect on input impedance. Alteration of the elasticity or relative lengths of the tubes results in shifts in the positions of the maxima and minima akin to those observed experimentally. Change in the viscosity of the walls or of the blood only affects the fluctuations of the impedance spectra without affecting the positions of the maxima and minima. Thus, with this still simple model, very realistic impedance spectra are obtainable. The model provides more insight than previously proposed models into the individual influence of various parameters of the proximal and peripheral vasculature on central hemodynamics.

Beta-2-microglobulin synthesis is increased during activation of human monocytes

We have investigated the regulation of beta 2-microglobulin (beta 2-M) synthesis by monocytes. Recent interest in beta 2-M has developed since the discovery that this protein forms amyloid fibrils in patients undergoing long-term, chronic hemodialysis. The beta 2-M amyloidosis is linked to the greatly elevated levels of monomeric beta 2-M in their circulation. Since factors that govern beta 2-M release from plasma membranes are not known, we endeavored to evaluate beta 2-M release during monocyte activation. Utilizing a human monocyte-like cell line, U937, we studied the effect of bacterial toxin stimulation on levels of membrane, cell surface, and supernatant beta 2-M. We now present a novel method to purify beta 2-M, a solid-phase radioimmunoassay to measure soluble beta 2-M, and an ELISA to measure membrane beta 2-M. Using these methods we found that the levels of beta 2-M in the cell membrane or on the cell surface did not change during monocyte activation. However, activation did induce a significant increase in the concentration of beta 2-M in monocyte supernatants, indicating that beta 2-M synthesis by monocytes is increased during monocyte activation. These results suggest that monocyte activation by hemodialysis membranes may be a contributing factor to the observed increase in circulating beta 2-M levels.

Normalization of hemodynamic parameters: application to vascular resistance and impedance

Comparison of hemodynamic parameters among different species is complicated by the wide variety of body sizes and shapes. Although some parameters such as blood pressure and flow velocity seem to have similar absolute values among species, most other parameters such as cardiac output, pulse wave velocity, and heart rate vary greatly. Comparisons would be facilitated if one uses indices that are independent of body size and/or shape. An ideal index will bring values for individuals or species of different sizes into the same range and yet exhibit large relative changes to responses to small increments of an intervention in an individual. In this paper we demonstrate how dimensional analysis together with Buckingham's pi theorem and the assumption of biological similarity can be used to derive dimensionless hemodynamic normalization indices. Using data from the literature and from our own laboratory, we illustrate the approach by examining resistance and impedance. We compare our results with previously proposed methods of accounting for different body sizes, namely, dividing impedance by resistance or vice versa, multiplying by body weight, and using flow velocity rather than volume flow in the calculations. Both of our proposed indices bring the values for arterial and pulmonary resistance and impedance for rats, rabbits, dogs, and humans into the same range, although the variability among species using our indices is twice that of those previously proposed. On the other hand, the relative changes of our two indices induced by vasoactive agents or exercise in a dog are from two to five times greater than either the absolute values themselves or the previously used indices.