ObjectiveTo analyze the biomechanics of ascending and descending stairs.MethodsThe moment of force of knee joint and contract strength of quadriceps muscles were analyzed by three dimensional motion analysis system and electromyograph (EMG) in three healthy men.ResultsFor the moment of force of knee joint, there were differences among different styles of ascending and descending stairs, but there were no differences in angles of knee joint flexion. The contract strength of quadriceps muscles during ascending stairs was stronger than that during descending stairs.Conclusion There are differences of knee joint moment and quadriceps muscles activities among 4 strategies during descending, and it is shown that quadriceps muscles' activities and knee joint moment became smaller during forward stepping, double stepping on one stair, side stepping, and 45°side stepping in sequence during descending stairs.

Based on the electrophysiologic mechanism of cardiac electrical action and the theory of voltage effect, the limit amplitude technique was employed to obtain the best clinical record effects. The results showed that limiter could limit the oversize signals overlapping each other and make the tiny signals magnification whthout distortion, such as the His bundle deflection in His Bundel Electrogram. At the same time, all signals recorded at multichannel physiologic recorder were clear and did not interfere with each other. Furthermore, the limiter not only improved the recording quality but also protected the cardiac electronic equipment because overdue stimulation signal was limited at a given electronic level during the recording of transesophageal pacing.

AIM: To explore the role of purinergic signaling mediated by ATP in the Alzheimer ’ s disease (AD)-related colon motility disorder and its related molecular mechanisms .METHODS:(1)Clinical trials:AD patients in our hospital were collected and studied .Radioimmunoassay was used for the determination of plasma motilin (MTL), cholecystokinin (CCK), vasoactive intestinal peptide (VIP) and nitric oxide (NO), and high-performance liquid chroma-tography ( HPLC) was applied to test the level of adenosine triphosphate ( ATP) .The patients were assessed by neuropsy-chology and scored accordingly .( 2 ) In animal experiments , AD mice received Morris water maze test , and the spatial learning and memory function were evaluated .The plasma levels of MTL , CCK, VIP and NO were examined by radioimmu-noassay , and the level of ATP was measured by HPLC .Choline acetyltransferase ( ChAT ) , VIP, nitric oxide synthase ( NOS) and ATP synthase were detected by immunohistochemistry .Western blot and immunohistochemistry were used to detect the expression of P2Y receptor.(3) In vitro, organ bath was applied to observe the effect of α,β-methylene ATP (α,β-MeATP), an agonist of P2Y receptor, on both spontaneous and electrically evoked contraction of colonic smooth muscle strip, and the technique of intracellular microelectrode was applied to observe the effect of α,β-MeATP on the membrane potential of colonic smooth muscle cells .RESULTS:Compared with control group , the levels of MTL and CCK were decreased (P<0.01), and the levels of NO and ATP were increased (P<0.05 or P<0.01), while the VIP level was not changed.Mini-Mental State Examination (MMSE) score was decreased (P<0.05), Alzheimer’s Disease Assess-ment Scale-Cognitive Subscale (ADAS-Cog) score, Neuropsychiatric Inventory (NPI) score and Alzheimer’s Disease Co-operative Study-Activities of Daily Living Scale ( ADCS-ADL ) were all increased as compared with control group ( P <0.01).The 4~6 d escape latency of APP/PS1 AD mice was significantly prolonged (P<0.05), and the space explora-tion ability distinctly reduced (P<0.05).In AD mice, the levels of MTL and CCK were decreased (P<0.01), and the levels of NO and ATP were increased (P<0.05 or P<0.01), while the VIP level was not changed .The protein expres-sion of colonic ATP synthase was significantly increased (P<0.05), but the expression of ChAT, VIP and NOS was not changed.The expression of P2Y receptor was increased (P<0.01).The results of in vitro experiment displayed that α,β-MeATP, from 20 μmol/L to 100 μmol/L, inhibited the spontaneous contraction of colonic smooth muscle strip in the nor-mal mice and AD mice ( P<0.05 or P<0.01 ) , and this inhibition was reversed by Na +channel inhibitor tetrodotoxin (TTX) (P<0.05 or P<0.01).In addition, the effect of α,β-MeATP at 100μmol/L on the AD mice was more obvious than that on the normal mice (P<0.05), and this inhibition was also antagonized by TTX (P<0.05 or P<0.01), pro-minent in AD group as compared with control group (P<0.05).In 10 Hz electrically evoked contraction of colonic smooth muscle strip,α,β-MeATP inhibited both the normal and AD mice (P<0.05 or P<0.01), while the inhibition was more obvious in the AD mice at the concentration of 40μmol/L or 100μmol/L (P<0.05 or P<0.01).CONCLUSION:AD patients and AD mice are accompanied by decreased MTL and CCK levels , and enhanced NO level , thus inducing colonic motor dysfunction along with AD .Meanwhile, ATP in plasma, purinergic neurons , and P2Y receptor expression are in-creased in the AD mice .Purinergic signaling mediated by ATP inhibits colonic smooth muscle strip contraction and further paralyzes the colonic movement function in AD .

Objective To explore the predictive value of blood pressure variability for long-term prognosis in elderly hypertension patients with coronary heart disease(CHD).Methods A total of 272 elderly patients with CHD and hypertension admitted to our hospital from January 2015 to January 2018 were enrolled retrospectively,and all of them were followed up for 5 years.Accord-ing to that they had adverse cardiovascular events or not,they were divided into adverse cardio-vascular events group(n=102)and control group(n=170).The differences in clinical features were compared between the two groups.ROC curve was plotted to analyze the value of blood pressure variability at first admission in predicting adverse cardiovascular events in elderly hyper-tension patients with CHD.Multivariate logistic regression analysis was applied to identify the risk factors for adverse cardiovascular events in these patients.Results Compared with the con-trol group,the incidence of diabetes,the proportion of coronary artery stenosis＞75％,and 24-hour SBP variability were significantly higher in the adverse cardiovascular events group(P＜0.05,P＜0.01).The area under curve value of 24-hour SBP variability in predicting adverse cardio-vascular events in elderly patients with CHD and hypertension was 0.777(95％CI:0.720-0.835,P=0.000).24-hour SBP variability ≥11.71 mm Hg(1 mm Hg=0.133 kPa,OR=5.017,95％CI:2.911-8.647,P=0.000),diabetes(OR=2.479,95％CI:1.231-4.993,P=0.011),and coronary artery stenosis＞75％(OR=2.303,95％CI:1.022-5.190,P=0.044)were independent risk factors for adverse cardiovascular events in elderly patients with CHD and hypertension.Conclusion 24-hour SBP variability can be used to predict the occurrence of adverse cardiovascu-lar events in elderly hypertension patients with CHD.

Polygraph has become a necessary instrument in interventional cardiology and fundamental research of medicine up to the present. In this study, a LabView development system (DS) (developed by NI in U.S.) used as software platform, a DAQ data acquisition module and universal computer used as hardware platform, were creatively coupled with our self-made low noise multi-channels preamplifier to develop Multi-channels electrocardiograph. The device possessed the functions such as real time display of physiological process, digit highpass and lowpass, 50Hz filtered and gain adjustment, instant storing, random playback and printing, and process control stimulation. Besides, it was small-sized, economically practical and easy to operate. It could advance the spread of cardiac intervention treatment in hospitals.
Electrocardiography ; instrumentation ; Monitoring, Intraoperative ; Monitoring, Physiologic ; Signal Processing, Computer-Assisted ; Software

OBJECTIVEDiscussion on utility and purposed value of obesity and abdomen obesity when body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) used as indexes predicting hypertension, hyper-blood glucose, and both clusters, to provide scientific basis for the decision on the indexes and their cut-off points of obesity and abdomen obesity in Chinese people.

METHODSUsing the data of diabetes mellitus (DM) from epidemiological studies carried out in 11 provinces/autonomous regions/municipalities of China from July 1995 to June 1997. Partial relative analysis, logistic multi-factors regression analysis, interaction analysis were used. Relative risk (RR), attributable risk proportion (ARP) and population attributable risk proportion (PARP) of hypertension, hyper-blood glucose, and the both cluster as BMI, WC, WHR with the different cut off points were analysed.

RESULTS1) The correlations between BMI, WC and blood pressure, blood glucose were better than the WHR. 2) After adjusted by age, sex, occupation leisure physical activity, education degree and the family history of DM, the results suggested that BMI, WC, WHR were important predictive factors, with relative importance as BMI > WC > WHR. 3) There were augment interactions on BMI, WC and WHR with hypertension, hyper-blood glucose, with the interaction of BMI and WC in particular. Their pure attributable interaction proportion were from 5.95% to 29.34%. 4) The values of RR were about 2.5 when BMI >/= 23, >/= 24 and >/= 25, suggesting the relationship with exposure factors and diseases were with medium and high maleficent extent. Their ARP were from 0.580 to 0.623 with PARP from 0.259 to 0.425. The values of RR were from 2.06 to 3.08 as WC >/= 85 cm in males, WC >/= 80 cm in females while WC >/= 90 cm in males, WC >/= 80 cm in females, which suggested that the relationship with exposure factors and diseases were in medium and high maleficent extent. Their ARP were from 0.515 to 0.676 while PARP from 0.241 to 0.431.

CONCLUSIONSSince the maleficent extent of exposure factors to diseases, the acceptability for overweight and obesity in population, and the prevention and care for overweight and obesity were just in the introduction stage in China. The utility value of predicted hypertension, hyper-blood glucose in BMI and WC seemed to be better then in WHR. We suggested that BMI used as the obesity index, with the diagnostic cut-off point BMI >/= 24. WC as the abdomen obesity index. The diagnostic cut-off points are suggested to be WC >/= 85 cm in males, and WC >/= 80 cm in females.

Adult ; Aged ; Blood Glucose ; metabolism ; Blood Pressure ; physiology ; Body Constitution ; Body Mass Index ; Diastole ; Female ; Humans ; Hyperglycemia ; diagnosis ; physiopathology ; Hypertension ; diagnosis ; physiopathology ; Logistic Models ; Male ; Middle Aged ; Obesity ; physiopathology ; Predictive Value of Tests ; Systole

Objective:To evaluate the post-marketing safety and immunogenicity of a 23-valent pneumococcal polysaccharide vaccine (PPV23).Methods:From September 2020 to June 2021, a clinical trial of single-dose PPV23 was conducted in people ≥3 years old in Centers for Disease Control and Prevention of Guizhou, Hunan and Fujian provinces. Blood samples were collects from the subjects before and 30 d after vaccination. ELISA was used to quantitatively detect IgG antibodies against capsular polysaccharides of 23 Streptococcus pneumoniae serotypes in serum samples. The adverse events (AEs) were monitored within 7 d after vaccination. Results:A total of 409 subjects were enrolled and included in safety analysis. Except for one with antibody level inversion, the other 408 participants were included in immunogenicity analysis. The levels of antibodies against the 23 Streptococcus pneumoniae serotypes were all increased after vaccination by an average of 4.24 folds. The two-fold growth rates of the antibodies ranged from 51.72% to 96.81% with a total two-fold growth rate of 78.59%. The overall rate of AEs was 27.14% (111/409). Local AEs were mainly pain, induration, redness and swollen. No serious adverse events related to vaccination occurred. Conclusions:This study preliminarily demonstrated the good immunogenicity and safety of PPV23 vaccine.

Objective:To describe the regional and demographic differences on passive non-smokers from 10 regions involved in the China Kadoorie Biobank (CKB) study.Methods:Detailed information regarding passive smoking behaviors related to 317 486 non-smokers who were 30-79 years old from the 10 study regions were gathered and analyzed.Results:Following the standardization of the 2010 China national population, the prevalence rate of passive smoking was 56.7 %, and the prevalence rate of living with smokers was 66.5 % among the Chinese adults. Both of the aforementioned rates were higher in rural than in urban areas. Meanwhile, the regional distribution of weekly passive smoking frequency and cumulative duration of passive smoking per week and cumulative duration of passive smoking per day were significantly different. The cumulative passive smoking duration per week increased along with the weekly frequency in people living in urban areas. Among women, the weekly passive smoking frequency was the highest, and the cumulative durations per week and per day appeared the lowest in Hunan, opposite to the situation in Henan. The prevalence of passive smoking among participants living with smokers was 2.27 times (95 %CI: 2.24 -2.29) of those who were not and the association appeared stronger in women ( OR=2.61, 95 %CI: 2.58-2.64) but not in men ( OR=1.01, 95 %CI: 0.95-1.06). Almost all the indicators seemed higher in women than those in men, except for the cumulative duration per day. Furthermore, these indicators appeared higher among those who were at younger age or with less education. The prevalence rates of passive smoking and living with smokers were lower but the cumulative duration per day was higher among those with lower household income. And the two rates were higher in married women and lower in married men, as compared to their counterparts. Conclusion:Regional and demographic differences in passive smoking were noticed among study population of CKB in the 10 regions.

Objective:To explore the correlation between chronic diseases and muscle mass, strength and quality in adults in China.Methods:Based on the second resurvey of China Kadoorie Biobank (CKB) in 2013-2014, logistic regression models were used to analyze the correlation of different types, number and duration of chronic diseases with low muscle mass, handgrip strength and muscle quality.Results:The prevalence rate of diabetes, coronary heart disease (CHD), stroke and chronic obstructive pulmonary disease (COPD) were 9.6%, 5.8%, 3.2% and 26.8%, respectively, and 38.8% of the participants had at least one disease, and they were more likely to have low handgrip strength and low arm muscle quality (AMQ), and the longer the chronic diseases duration, the higher the risk. The ORs (95% CIs) for low handgrip strength and low AMQ in patients with 1 chronic disease for more than 10 years was 1.64 (1.42-1.90) and 1.83 (1.60-2.10), respectively. The ORs (95% CIs) for low handgrip strength were 1.26 (1.17-1.37), 1.42 (1.23-1.64) and 2.27 (1.55-3.32) and the ORs (95% CIs) for low AMQ were 1.28 (1.18-1.38), 1.67 (1.46-1.92) and 2.41(1.69-3.45), respectively, in patients with 1, 2, ≥3 chronic diseases, the correlation showed a linear trend ( P for trend <0.001). Diabetes, CHD and stroke were positively correlated with low handgrip strength and low AMQ. Compared with participants without COPD, COPD patients were more likely to have low appendicular skeletal muscle mass index (ASMI), low total skeletal muscle mass index (TSMI) and low handgrip strength, and the risk was positively correlated with disease duration. Conclusions:Patients with chronic diseases were more likely to have lower muscle strength and muscle quality, especially the patients with multi diseases and longer disease duration. The proportion of low handgrip strength and low AMQ was higher in patients who reported multi-prevalence and longer duration of chronic diseases.

Objective:To evaluate the correlation of dietary patterns with low muscle mass, strength and quality in Chinese adults.Methods:Based on the second resurvey of China Kadoorie Biobank, factor analysis was conducted to derive dietary patterns from 20 food groups. Low muscle mass, strength, and quality were defined as the sex-specific lowest quintile of appendicular skeletal muscle mass index (ASMI), total skeletal muscle mass index (TSMI), handgrip strength and arm muscle quality (AMQ) according to Asian Working Group for Sarcopenia recommendations. Logistic regression models were used to evaluate the correlation of dietary patterns with low muscle mass, strength, and quality.Results:Two major dietary patterns were extracted. The balanced dietary pattern was characterized by the intake of a variety of foods, whereas the rice-meat dietary pattern was characterized by high intakes of rice, meat, poultry and fish. Individuals who had the highest quintile score of the balanced dietary pattern were less likely to have low TSMI, handgrip strength or AMQ( OR=0.83, 95% CI: 0.74-0.95 for low TSMI; OR=0.64, 95% CI: 0.56-0.74 for low handgrip strength; OR=0.82, 95% CI: 0.72-0.93 for low AMQ; for trend P<0.05). And those who scored higher on the rice-meat dietary pattern had lower risk of low muscle mass and strength ( OR=0.67, 95% CI: 0.55-0.82 for low ASMI; OR=0.69, 95% CI: 0.56-0.85 for low TSMI; OR=0.74, 95% CI: 0.60-0.91 for low handgrip strength; for trend P<0.05). Conclusion:Individuals followed the balanced dietary pattern, as well as those who followed the rice-meat dietary pattern, had better levels of skeletal muscle mass, strength and quality.