A prospective study on application of human umbilical cord mesenchymal stem cells combined with autologous Meek microskin transplantation in patients with extensive burns / 中华烧伤杂志

Objective: To investigate the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) combined with autologous Meek microskin transplantation on patients with extensive burns. Methods: The prospective self-controlled study was conducted. From May 2019 to June 2022, 16 patients with extensive burns admitted to the 990th Hospital of PLA Joint Logistics Support Force met the inclusion criteria, while 3 patients were excluded according to the exclusion criteria, and 13 patients were finally selected, including 10 males and 3 females, aged 24-61 (42±13) years. A total of 20 trial areas (40 wounds, with area of 10 cm×10 cm in each wound) were selected. Two adjacent wounds in each trial area were divided into hUCMSC+gel group applied with hyaluronic acid gel containing hUCMSCs and gel only group applied with hyaluronic acid gel only according to the random number table, with 20 wounds in each group. Afterwards the wounds in two groups were transplanted with autologous Meek microskin grafts with an extension ratio of 1∶6. In 2, 3, and 4 weeks post operation, the wound healing was observed, the wound healing rate was calculated, and the wound healing time was recorded. The specimen of wound secretion was collected for microorganism culture if there was purulent secretion on the wound post operation. In 3, 6, and 12 months post operation, the scar hyperplasia in wound was assessed using the Vancouver scar scale (VSS). In 3 months post operation, the wound tissue was collected for hematoxylin-eosin (HE) staining to observe the morphological changes and for immunohistochemical staining to observe the positive expressions of Ki67 and vimentin and to count the number of positive cells. Data were statistically analyzed with paired samples t test and Bonferronni correction. Results: In 2, 3, and 4 weeks post operation, the wound healing rates in hUCMSC+gel group were (80±11)%, (84±12)%, and (92±9)%, respectively, which were significantly higher than (67±18)%, (74±21)%, and (84±16)% in gel only group (with t values of 4.01, 3.52, and 3.66, respectively, P<0.05). The wound healing time in hUCMSC+gel group was (31±11) d, which was significantly shorter than (36±13) d in gel only group (t=-3.68, P<0.05). The microbiological culture of the postoperative wound secretion specimens from the adjacent wounds in 2 groups was identical, with negative results in 4 trial areas and positive results in 16 trial areas. In 3, 6, and 12 months post operation, the VSS scores of wounds in gel only group were 7.8±1.9, 6.7±2.1, and 5.4±1.6, which were significantly higher than 6.8±1.8, 5.6±1.6, and 4.0±1.4 in hUCMSC+gel group, respectively (with t values of -4.79, -4.37, and -5.47, respectively, P<0.05). In 3 months post operation, HE staining showed an increase in epidermal layer thickness and epidermal crest in wound in hUCMSC+gel group compared with those in gel only group, and immunohistochemical staining showed a significant increase in the number of Ki67 positive cells in wound in hUCMSC+gel group compared with those in gel only group (t=4.39, P<0.05), with no statistically significant difference in the number of vimentin positive cells in wound between the 2 groups (P>0.05). Conclusions: The application of hyaluronic acid gel containing hUCMSCs to the wound is simple to perform and is therefore a preferable route. Topical application of hUCMSCs can promote healing of the autologous Meek microskin grafted area in patients with extensive burns, shorten wound healing time, and alleviate scar hyperplasia. The above effects may be related to the increased epidermal thickness and epidermal crest, and active cell proliferation.

Association between metabolically healthy obesity and incident risk of stroke in adult aged over 40 from rural Henan province / 中华预防医学杂志

Objective: To investigate the association between metabolically healthy obesity and the incident risk of stroke in people aged ≥40 years from rural areas of Henan Province. Methods: During 2007 to 2008, 20 194 residents aged ≥18 years were selected for baseline examination by random cluster sampling and 17 265 participants were followed up during 2013 to 2014. According to the aim of current study, a total of 11 864 eligible subjects were included in this post-hoc analysis. Depending on body mass index and metabolic status, subjects were divided into four groups: metabolically healthy normal weight, metabolically healthy obesity, metabolically abnormal normal weight and metabolically abnormal obesity. Multivariate logistic regression model was used to analyze the relationship between metabolically healthy obesity and the risk of stroke. Results: The median (Q1, Q3) age of study participants was 54(46, 61) years, and 4 526 participants were men. During the mean follow-up of 6 years, the cumulative incidence of stroke was 7.16%. The incidence of stroke in metabolically healthy normal weight, metabolically healthy obesity, metabolically abnormal normal weight, and metabolically abnormal obesity were 3.73%, 4.61%, 8.99% and 9.38%, respectively (χ²=117.458, P<0.001). After adjusting possible confounding factors, compared with metabolically healthy normal weight, the risk of stroke was significantly increased in the metabolically healthy obesity group, metabolically abnormal normal weight group and metabolically abnormal obesity group with the odds ratio (OR) and 95% confidence interval (CI) of 1.52(1.10-2.12), 2.11(1.61-2.77) and 2.78(2.18-3.55), respectively. Stratified analysis showed that the risk of stroke was significantly higher in metabolically healthy obesity people aged 40-59 years compared with metabolically healthy normal weight group (OR=2.12, 95%CI: 1.36-3.30). Conclusion: Metabolically healthy obesity, metabolically abnormal normal weight and metabolically abnormal obesity are positively associated with the risk of stroke.

Association of cardiovascular diseases with milk intake among general Chinese adults / 中华医学杂志(英文版)

BACKGROUND@#The association of milk intake with cardiovascular disease (CVD) and cause-specific mortality remained controversial and evidence among the Chinese population was limited. We aimed to study the relationship between milk intake and CVDs among general Chinese adults.@*METHODS@#A total of 104,957 participants received questionnaire survey. Results of physical examination such as anthropometric measurements and biochemical tests during 2007 to 2008, demographic data and their information on milk intake were collected through standardized questionnaires. Cox proportional hazard regression models were used to calculate hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) of CVD incidence, cause-specific mortality and all-cause mortality related to milk intake. Restricted cubic splines (RCSs) were applied to examine dose-response associations.@*RESULTS@#Among the 91,757 participants with a median follow-up period of 5.8 years, we documented 3877 CVD cases and 4091 all-cause deaths. Compared with participants who never consumed milk, the multivariate-adjusted HRs (95% CIs) of CVD incidence for 1 to 150 g/day, 151 to 299 g/day, and ≥300 g/day were 0.94 (0.86-1.03) (P > 0.05), 0.77 (0.66-0.89) (P < 0.05), and 0.59 (0.40-0.89) (P < 0.05), respectively; each 100 g increase of daily milk intake was associated with 11% lower risk of CVD incidence (HR, 0.89; 95% CI: 0.85-0.94; P < 0.001), and 11% lower risk of CVD mortality (HR, 0.89; 95% CI: 0.82-0.97; P = 0.008) after adjustment for age, sex, residential area, geographic region, education level, family history of CVD, smoking, alcohol drinking, physical activity level, body mass index, and healthy diet status (ideal or not). RCS analyses also showed a linear dose-response relationship with CVD (P for overall significance of the curve <0.001; P for non-linearity = 0.979; P for linearity <0.001) and stroke (P for overall significance of the curve = 0.010; P for non-linearity = 0.998; P for linearity = 0.002) incidence, and CVD mortality (P for overall significance of the curve = 0.045; P for non-linearity = 0.768; P for linearity = 0.014) within the current range of daily milk intake.@*CONCLUSIONS@#Daily milk intake was associated with lower risk of CVD incidence and mortality in a linear inverse relationship. The findings provide new evidence for dietary recommendations in CVD prevention among Chinese adults and people with similar dietary pattern in other countries.

The sex- and age-specific association between resting heart rate and hypertension in rural adult residents of Henan province / 中华心血管病杂志

Objective: To investigate the sex- and age-specific association between resting heart rate and hypertension in rural adult residents of Henan province. Methods: At baseline, a total of 20 194 participants were randomly selected from Xin'an County of Henan province between July 2007 and August 2008. After excluding participants with hypertension or without resting heart rate data at baseline, and participants died or without hypertension outcome or diagnosed as gestational hypertension during follow-up between July 2013 and October 2014, 10 212 participants were finally included in this study. Multiple linear regression model was used to examine the association between resting heart rate and change of blood pressure. Logistic regression model was used to estimate the association between resting heart rate and risk of hypertension. Results: There were 2 059 new hypertensive cases (839 male) during the 6 years follow-up. After controlling for potential confounders, per 5 beats/minutes increases in resting heart rate was associated with 0.18 mmHg (1 mmHg=0.133 kPa) (95%CI 0.01-0.36 mmHg, P=0.046) absolute increase in systolic blood pressure and 7% higher risk of developing hypertension in women (95%CI 1.03-1.11, P<0.05). Compared with resting heart rate<70 beats/minutes, the adjusted RRs for 76-82 and>82 beats/minutes groups were 1.39 (95%CI 1.18-1.63, P<0.05) and 1.22 (95%CI 1.02-1.45, P<0.05), respectively. For both age groups, increased resting heart rate was positively associated with risk of hypertension in women(RR=1.05(95% CI 1.01-1.10), P<0.05 (the women those <60 years); RR=1.14(95% CI 1.04-1.25), P<0.05 (the women those≥60 years). However, no significant association was found between resting heart rate and hypertension in male residents. Conclusions: Increased resting heart rate is associated with high risk of hypertension in women who live in rural area, especially in elder women of this cohort.

Cardiovascular disease risk in diabetes patients aged 40 years old and above in China / 中华心血管病杂志

Objective: To evaluate the incidence of cardiovascular disease (CVD), ischemic and hemorrhagic cardiovascular events among Chinese diabetic patients aged 40 years and above with different CVD risk levels. Methods: This study enrolled participants aged 40 years and above in 15 provinces from a prospective cohort study, the China-PAR project (Prediction for Atherosclerotic Cardiovascular Disease Risk in China). Participants were categorized into two groups according to the presence or absence of diabetes at baseline. Individuals were further classified into low (0-4.9%), moderate (5%-9.9%) and high risk groups (≥10%), based on predicted ten-year CVD risk using the China-PAR equations. Two followed-up surveys were conducted between 2007 and 2015 to identify CVD events, which were defined as nonfatal acute myocardial infarction, or death due to coronary heart disease, or stroke. Ischemic cardiovascular events included nonfatal acute myocardial infarction, or death due to coronary heart disease, or ischemic stroke. Hemorrhagic cardiovascular events included subarachnoid hemorrhage and intracerebral hemorrhage. The incidences of CVD, ischemic and hemorrhagic cardiovascular events were compared in diabetes and non-diabetes population with different CVD risk levels. Results: This study included 89 209 participants aged 40 years and above, the average follow-up period was 8.5 years. The age was (54.8±9.4) years, and 36 794 (41.2%) were men, and 5 730 (6.4%) were diabetic patients. In diabetes patients aged 40 years and above, 53.7% (3 075/5 730) were at high risk of CVD. Age-and sex-adjusted incidence of CVD, ischemic and hemorrhagic cardiovascular events (1 066.93/100 000 person-years, 824.23/100 000 person-years, and 211.56/100 000 person-years) were significantly lower in diabetes patients than those in non-diabetes population with high CVD risk (1 773.73/100 000 person-years, 1 228.18/100 000 person-years, and 446.49/100 000 person-years) (all P<0.001). Among high CVD risk populations, incidence of ischemic events was significantly higher in diabetic patients than in non-diabetes population (1 638.47/100 000 person-years vs. 1 228.18/100 000 person-years, P<0.001), but incidence of hemorrhagic events tended to be lower in diabetic patients than in non-diabetes population (415.70/100 000 person-years vs. 446.49/100 000 person-years, P=0.635). Incidence of ischemic and hemorrhagic events were similar between diabetes patients and non-diabetes population at low or moderate CVD risk groups (all P>0.05). Conclusions: More than half of diabetes patients aged 40 years and above in China have high CVD risk. The incidence of CVD, ischemic and hemorrhagic cardiovascular events are different in diabetic patients with different CVD risk levels.

Association of the ADIPOQ Rs2241766 and Rs266729 Polymorphisms with Metabolic Syndrome in the Chinese Population: A Meta-analysis / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This meta-analysis was performed to summarize the association of the ADIPOQ rs2241766 and rs266729 polymorphisms with metabolic syndrome (MS) in the Chinese population.</p><p><b>METHODS</b>We searched for articles in MEDLINE via PubMed, EMBASE, HuGE Navigator, CNKI, and Wanfang databases and calculated odds ratios (ORs) with 95% confidence intervals (CIs) to determine the strength of associations in fixed- or random-effects models.</p><p><b>RESULTS</b>We included 21 articles in the meta-analysis: 17 reports of ADIPOQ rs2241766 with 3628 cases and 3000 controls and 8 of rs266729 with 2021 cases and 2226 controls. We found an increased risk of MS with the ADIPOQ rs2241766 polymorphism in some genetic models (allele model: OR=1.12, 95% CI: 1.03-1.21; dominant model: OR=1.15, 95% CI: 1.04-1.28; homozygote model: OR=1.22, 95% CI: 1.00-1.49) but no association with the ADIPOQ rs266729 polymorphism (allele model: OR=0.98, 95% CI: 0.82-1.17; dominant model: OR=0.90, 95% CI: 0.79-1.02; recessive model: OR=1.09, 95% CI: 0.85-1.39; homozygote model: OR=1.03, 95% CI: 0.80-1.33).</p><p><b>CONCLUSION</b>The results of this meta-analysis suggest an association between the ADIPOQ rs2241766 polymorphism and MS in the Chinese population. G allele of ADIPOQ rs2241766 increases the risk of MS. Better designed studies with different ethnic populations and larger sample sizes are needed for assessing the relationship between ADIPOQ rs2241766 and rs266729 polymorphisms and MS in the future.</p>

Association of TCF7L2 and GCG Gene Variants with Insulin Secretion, Insulin Resistance, and Obesity in New-onset Diabetes / 生物医学与环境科学（英文）

This cohort study was designed to evaluate the association of transcription factor 7-like 2 (TCF7L2) and proglucagon gene (GCG) variants with disordered glucose metabolism and the incidence of type 2 diabetes mellitus (T2DM) in a rural adult Chinese population. A total of 7,751 non-T2DM participants ⋝18 years old genotyped at baseline were recruited. The same questionnaire interview and physical and blood biochemical examinations were performed at both baseline and follow-up. During a median 6 years of follow-up, T2DM developed in 227 participants. After adjustment for potential contributory factors, nominally significant associations were seen between TT genotype and the recessive model of TCF7L2 rs7903146 and increased risk of T2DM [hazard ratio (HR)=4.068, 95% confidence interval (CI): 1.270-13.026; HR=4.051, 95% CI: 1.268-12.946, respectively]. The TT genotype of rs7903146 was also significantly associated with higher fasting plasma insulin level and the homeostasis model assessment of insulin resistance in case of new-onset diabetes. In addition, the TCF7L2 rs290487 TT genotype was associated with abdominal obesity and the GCG rs12104705 CC genotype was associated with both general obesity and abdominal obesity in case of new-onset diabetes.

The Status and Associated Factors of Successful Aging among Older Adults Residing in Longevity Areas in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>This study aims to assess the status of successful aging (SA) in longevity areas in China and explore multiple factors associated with SA among the young-old and oldest-old.</p><p><b>METHODS</b>A total of 2296 elderly people aged 65 and older were interviewed in the longevity areas sub-sample of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2012. Baseline assessments included a researcher-administered questionnaire, physical examination, and laboratory testing. A logistic regression model was used to identify factors associated with SA.</p><p><b>RESULTS</b>The prevalence of SA was 38.81% in the CLHLS in 2012. There were significant differences between ages groups, with SA compromising 56.85% among ⋝65 years group and 20.31% among ⋝100 years group (χ2trend=126.73, P<0.01). The prevalence of SA among females was 33.59%, which was significantly lower than that among males (45.58%) (χ2gender=33.65, P<0.05). In the regression analysis, having anemia (OR=0.744, 95% CI: 0.609-0.910), poor lifestyle (OR=0.697, 95% CI: 0.568-0.854), poor sleep quality (OR=0.558, 95% CI: 0.456-0.682), and central obesity (OR=0.684, 95% CI: 0.556-0.841) were the main factors associated with SA. The promoting SA rate decreased as age increased, and the group of 65-79 years had higher odds than the other age group.</p><p><b>CONCLUSION</b>Preventing central obesity, improving sleep quality and promoting healthy lifestyle may contribute to achieve SA among the elderly.</p>

Association between Low-density Lipoprotein Receptor-related Protein 5 Polymorphisms and Type 2 Diabetes Mellitus in Han Chinese: a Case-control Study / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the association between low-density lipoprotein receptor-related protein 5 (LRP5) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese.</p><p><b>METHODS</b>A total of 1842 T2DM cases (507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms (SNPs). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to describe the strength of the association by logistic regression.</p><p><b>RESULTS</b>In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2DM, even after adjusting for relevant covariates. When stratified by body mass index (BMI), the two SNPs were also not associated with T2DM. Among the 3 common haplotypes, only haplotype TT was associated with reduced risk of T2DM (OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI (P<0.001) and rs4930588 was associated with triglyceride levels (P=0.043) in 507 newly diagnosed T2DM cases but not in healthy controls.</p><p><b>CONCLUSION</b>No LRP5 variant was found to be associated with T2DM in Han Chinese, but haplotype TT was found to be associated with T2DM.</p>

Financial burden of hepatitis B-related diseases and factors influencing the costs in Shenzhen,China / 中华流行病学杂志

Objective To investigate the direct, indirect and intangible costs due to hepatitis B-related diseases and to explore main factors associated with the costs in Shenzhen. Methods Cluster sampling for cases collected consecutively during the study period was administrated. Subjects were selected fiom eligible hepatitis B-related patients. By pre-trained professional investigators,health economics-related information was collected, using a structured questionnaire. Hospitalization expenses were obtained through hospital records after the patients were discharged from hospital.Total economic burden of hepatitis B-related patients would involve direct, indirect and intangible costs. Direct costs were further divided into direct medical costs and direct nonmedical costs. Human Capital Approach was employed to measure the indirect costs both on patients and the caregivers in 1-year time span. Willing to pay method was used to estimate the intangible costs. Multiple linear stepwise regression models were conducted to determine the factors linked to the economic burden.Results On average, the total annual cost of per patient with hepatitis B-related diseases was 81 590.23 RMB Yuan. Among which, direct, indirect and intangible costs were 30 914.79 Yuan (account for 37.9% ), 15 258.01 Yuan (18.7% ), 35 417.43 Yuan (43.4%), respectively. The total annual costs per patient for hepatocellular carcinoma, severe hepatitis B, decompensated cirrhosis,compensated cirrhosis, chronic hepatitis B and acute hepatitis B were 194 858.40 Yuan, 144 549.20 Yuan, 120 333.60 Yuan, 79 528.81 Yuan, 66 282.46 Yuan and 39 286.81 Yuan, respectively. The ratio of direct to indirect costs based on the base-case estimation foot add to 2.0∶1, increased from hepato-eellular carcinoma (0.7∶1)to compensated cirrhosis (3.5∶ 1 ), followed by acute hepatitis B (3.3∶1 ), severe hepatitis B (2.8∶1 ), decompensate cirrhosis (2.3:1)and chronic hepatitis B(2.2∶1 ).Direct medical costs were more than direct nonmedical. Ratio between the sum total was 16∶1. The proportions of total annual cost per patient with hepatitis B-related diseases accounted for annual patient income were 285.3%, and 75.4% for annual household income. Furthermore, proportions of direct costs accounted for annual patient income and annual household income were 108.1% and 28.6%. The total annual indirect cost per person was 8123.38 Yuan for patients of all hepatitis B-related diseases, while 7134.63 Yuan for caregivers. Corresponding work-loss days were 55.74 days for patients and 19.83 days for caregivers. Based on multiple linear stepwise regression analysis, age of patients was a common influencing factor to all kinds of costs. Other factors were as follows:complicated with other diseases, antiviral medication, monthly household income and selfmedications. Conclusion The economic burden of hepatitis B-related diseases was substantial for patients and their families. All costs tended to increase with the severity of disease. The direct costs were larger than the indirect costs. And the direct medical costs were more than the direct ones.Indirect costs based on patients were larger than the ones of caregivers.

Multilevel regression analysis on region duster and risk factors of hypertension in the Chinese adult population / 中华流行病学杂志

Objective To analyze the region cluster and risk factors of hypertension in the Chinese adult population and to explore the application of multilevel regression model in the risk factors of hypertension. Methods Multi-stage random sampling technique was used to choose 15 540 individuals aged 35-74 years from 10 regions in China. Two-level logistic regression models were fitted under MLwiN 2.02 software. Results The region cluster of hypertension existed and variance portion coefficient was 3.1%. After adjusting for the age and gender, overall obese people (BMI≥28 kg/m2) were 4.50(95%CI: 4.00-5.06) times, overweight people (BMI=24-27.9 kg/m2) were 2.26 (95%CI: 2.07-2.46) times more likely to be hypertensive as compared with those of normal BMI (18.5-23.9 kg/m2), and those centrally obesive people (Waist circumference≥85 cm in male or 80 cm in female) were 2.62 (95%CI: 2.42-2.83) times more likely to be hypertensive as compared with those of normal WC. The age-and gender-adjusted odds ratios (Ors) of triglyceride (TG), serum total cholesterol (TC), glucose, low-density lipoprotein cholesterol (LDL-C) , high-density lipoprotein cholesterol (HDL-C) and drinking alcohol were 2.10 (95% CI: 1.89-2.33) , 2.08 (95% CI: 1.84-2.35) , 1.85 (95% CI: 1.60-2.14) , 1.58 (95% CI: 1.38-1.81), 1.49(95%CI: 1.32-1.69) and 1.15(95%CI: 1.05-1.27), respectively. Conclusion The prevalence of hypertension was not only affected by individual risk factors, such as obesity, drinking alcohol, abnormal glucose and serum lipids profile, but also affected by the geographic environment where people resided in. Population-and risk factors targeted strategies, proved a promising way to reduce individual risk of hypertension in the primary prevention of hypertension.

Perilipin gene 1237 T > C polymorphism is not associated with obesity risk in northern Chinese Han adults / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To identify the association between PLIN 1237 polymorphism and obesity in Chinese Han adults.</p><p><b>METHODS</b>A total of 994 adults (157 obese subjects, 322 overweight subjects, and 515 normal controls) were recruited from two rural communities. PLIN 1237 polymorphism was genotyped by polymerase chain reaction-restriction-fragment-length-polymorphism (PCR-RFLP). Association between PLIN polymorphisms and obesity status was estimated by ordinal logistic regression.</p><p><b>RESULTS</b>The three genotypes of PLIN 1237 were detected with a percentage of 54.3%, 37.1%, and 8.6% in TT, TC, and CC genotypes, respectively. For the PLIN 1237 polymorphism locus, the frequency of alleles T and C was 0.73 and 0.27, respectively. The PLIN 1237 polymorphisms were in Hardy-Weinberg equilibrium. PLIN 1237 polymorphism was not associated with obesity. The odds ratio for overweight or obesity for the CC+TC genotype was 0.8 (0.4, 1.4) in women (P = 0.4) and 0.6 (0.3, 1.3) in men (P = 0.2) after adjustment for age, education, household income and alcohol consumption, smoking, and physical activity.</p><p><b>CONCLUSION</b>Chinese Han adults have a lower frequency of variant-allele C in PLIN 1237. PLIN 1237 T > C polymorphism is not significantly associated with obesity in northern Chinese adults.</p>

Epidemiological and molecular characterization of seasonal influenza A/H3N2 viruses circulating in Shenzhen, 2005 - 2007 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To determine the epidemiological characteristics of seasonal influenza in Shenzhen from 2005 to 2007 and the molecular variation of HA1 domain of influenza H3N2 viruses.</p><p><b>METHODS</b>The consultation rate for influenza-like illness (ILI) were calculated weekly for indicating the influenza activities (the Shenzhen Influenza Surveillance System mainly consisted of 16 institutions with 9 hospitals, 6 districts and one municipal centers of disease control and prevention). Pharyngeal swabs from the cases of ILI, which were collected during 2005 to 2007 from the city-wide and quality-controlled surveillance network, were used to propagate the viruses. The HA1 region of the influenza A/H3N2 viruses were detected by RT-PCR and sequenced subsequently. The analyses of pairwise amino acid variations, genetic clustering and phylogenetics was performed.</p><p><b>RESULTS</b>The activity levels of influenza showed certain changes during each year from 2005 to 2007, and there were summer peaks from May to July in 2006 and 2007. The positive rates of influenza virus were 4.78% (114/2385), 5.77% (212/3674) and 12.12% (343/2831) from 2005 to 2007 respectively. The weekly isolating rates changed accordingly with the trend of the percentages of ILI. The proportions of influenza H3N2 virus were 25.46% (28/114) and 2.83% (6/212) in 2005 and in 2006 respectively, but the proportion increased to 62.68% (215/343), which indicated that H3N2 virus became the predominant strain in 2007. Phylogenetic clustering analysis of influenza H3N2 virus revealed that there were 5 clades. The viruses which were isolated in 2005 contained in the clade I and II, the viruses in 2006 were comprised in clade III, and clade IV and V included the viruses isolated in 2007. Although the stem of cladogram developed with one accord of the time isolated viruses, the viruses which were similar to vaccine strains had circulated in Shenzhen before a given strain was determined as vaccine strain by WHO. It was also noticed that more amino acid changes at antigenic sites, especially at sites A and B in the H3N2 viruses, were found in 2007 than that in 2005 and in 2006. But the sequences at the receptor-binding sites and disulphide bond sites were conserved and no new circulating strain for genetic reassortment had been found in the period.</p><p><b>CONCLUSION</b>Shenzhen might be one of areas where the ongoing genetic drift of influenza H3N2 viruses appeared earlier in China. The changes of influenza H3N2 virus showed the active status in the population. The results suggested that monitoring seasonal influenza viruses by sequence analysis could provide important and timely information on the appearance of strains with epidemiologic significance.</p>

Study on molecular epidemiological characteristics of influenza H1N1 viruses circulating in Shenzhen,China from 2005 to 2007 / 中华流行病学杂志

Objective To study the genetic and epidemiological characteristics of HA1 of influenza H1N1 viruses circulating in Shenzhen from 2005 to 2007. Methods The HA1 region was analyzed by RT-PCR and subsequently sequenced to analyze the HA1 genetic evolution. Phylogenetic analysis was confirmed on the homology of nucleitide comparing with the reference viruses of vaccines recommended by WHO and representative virus confirmed by China CDC. Relationship between isolation rates and genetic evolutions was explored. Results The average isolation rate from 2005 to 2007 was 7.16%. Of the isolates, the proportions of influenza H1N1 viruses in 2005, 2006 and 2007 were 56.14%, 66.03%,3.61% ,respectively. Data from HA1 phylogenetic analysis showed that there were at least three clades circulated in Shenzhen. Different viruses isolated during January to April were clustered with A/New Caledonia/20/1999 viruses isolated in the latter months of 2005 clustered with A/Solomon Island/3/2006 and viruses from 2006 to 2007 were in the same clade with A/GDLH/219/2006. Results showed that most viruses had a deletion of lysine at position 130. Compared with A/New Caledonia/20/1999, the virus isolated after May of 2005 occurred T82K, Y94H, R146K, R209K, T267N amino acid substitution, while some virus isolated after May 2006 took place the amino acid substitutions of A190T, H193Y,E195D (located at antigenic site B) and R146K(antigenic site A). The sequences at the receptor-binding sites and glycosylation sites were conserved. Compared with referring viruses, A/SZ/68/2007 had 50 amino acid substitutions in the HA1 region.Of these,eleven and six were located at antigenic sites and receptor-binding sites,respectively.Four amino acid substitution resulted in the deletion of glycosylation site.Conclusion Three different genetic lineages of influenza H1N1 virus were circulated in the population in Shenzhen during 2005-2007.The special virus named A/SZ/68/2007 should be paid further attention on its antigenic and epidemiological characteristics.

Secular trend of nosocomial pneumonia in an university hospital in Zhengzhou / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the secular trend of infection rate, risk factor exposure rates for nosocomial pneumonia (NP), and to evaluate the nosocomial infection surveillance and control programs efficacy in an university hospital from 1993 to 2000.</p><p><b>METHODS</b>All 126 665 hospitalized patients from 1993 to 2000 were studied for NP. The independent risk factors for NP were analyzed by using case-control study method and logistic regression technique. The time-specific rates for NP and risk factor exposure were calculated annually.</p><p><b>RESULTS</b>The infection rates for NP were decreased by 50% from 1.20% in 1993 to 0.60% in 2000. The logistic regression analysis showed that the independent risk factors for NP were immunosuppressive therapy (OR = 2.72), chemotherapy (OR = 2.17), cancer (OR = 1.45), chronic obstructive pulmonary disease (COPD, OR = 1.88), ICU (OR = 3.18), coma (OR = 3.26), tracheotomy (OR = 14.95), hemodialysis (OR = 5.12), bone or lumbar puncture (OR = 1.82). The time-trends for exposure rates of COPD and bone or lumbar puncture were slightly decreased, however those for the others and the synthetic risk factors were not changed significantly.</p><p><b>CONCLUSION</b>The infection rates for NP were significantly decreased in the case of no change for exposure rates of risk factors for NP, this suggests that the nosocomial infection surveillance and control programs were effective for lowering infection rate for NP in this hospital.</p>