[Relationship between body mass index and sexual development in Chinese children].

Objective: To investigate the relationship between body mass index (BMI) and sexual development in Chinese children. Methods: A nationwide multicenter and population-based large cross-sectional study was conducted in 13 provinces, autonomous regions and municipalities of China from January 2017 to December 2018. Data on sex, age, height, weight were collected, BMI was calculated and sexual characteristics were analyzed. The subjects were divided into four groups based on age, including ages 3-<6 years, 6-<10 years, 10-<15 years and 15-<18 years. Multiple Logistic regression models were used for evaluating the associations of BMI with sexual development in children. Dichotomous Logistic regression was used to compare the differences in the distribution of early and non-early puberty among normal weight, overweight and obese groups. Curves were drawn to analyze the relationship between the percentage of early puberty and BMI distribution in girls and boys at different Tanner stages. Results: A total of 208 179 healthy children (96 471 girls and 111 708 boys) were enrolled in this study. The OR values of B2, B3 and B4+ in overweight girls were 1.72 (95%CI: 1.56-1.89), 3.19 (95%CI: 2.86-3.57), 7.14 (95%CI: 6.33-8.05) and in obese girls were 2.05 (95%CI: 1.88-2.24), 4.98 (95%CI: 4.49-5.53), 11.21 (95%CI: 9.98-12.59), respectively; while the OR values of G2, G3, G4+ in overweight boys were 1.27 (95%CI: 1.17-1.38), 1.52 (95%CI: 1.36-1.70), 1.88 (95%CI: 1.66-2.14) and in obese boys were 1.27 (95%CI: 1.17-1.37), 1.59 (95%CI: 1.43-1.78), and 1.93 (95%CI: 1.70-2.18) (compared with normal weight Tanner 1 group,all P<0.01). Analysis in different age groups found that OR values of obese girls at B2 stage and boys at G2 stage were 2.02 (95%CI: 1.06-3.86) and 2.32 (95%CI:1.05-5.12) in preschool children aged 3-<6 years, respectively (both P<0.05). And in the age group of 6-10 years, overweight girls had a 5.45-fold risk and obese girls had a 12.54-fold risk of B3 stage compared to girls with normal BMI. Compared with normal weight children, the risk of early puberty was 2.67 times higher in overweight girls, 3.63 times higher in obese girls, and 1.22 times higher in overweight boys, 1.35 times higher in obese boys (all P<0.01). Among the children at each Tanner stages, the percentage of early puberty increased with the increase of BMI, from 5.7% (80/1 397), 16.1% (48/299), 13.8% (27/195) to 25.7% (198/769), 65.1% (209/321), 65.4% (157/240) in girls aged 8-<9, 10-<11 and 11-<12 years, and 6.6% (34/513), 18.7% (51/273), 21.6% (57/264) to 13.3% (96/722), 46.4% (140/302), 47.5% (105/221) in boys aged 9-<10, 12-<13 and 13-<14 years, respectively. Conclusions: BMI is positively correlated with sexual development in both Chinese boys and girls, and the correlation is stronger in girls. Obesity is a risk factor for precocious puberty in preschool children aged 3-<6 years, and 6-<10 years of age is a high risk period for early development in obese girls.

[Survey of height and weight of children and adolescents at different Tanner stages in urban China].

Objective: To investigate the status of height and weight of 3-18-year-old children and adolescents in urban China, and to provide a basis for establishing puberty phase specific curves for age-specific height and age-specific weight. Methods: A cross-sectional survey of 218 185 children and adolescents aged 3-18 years in urban China was conducted by using the method of stratified random cluster sampling from January 2017 to December 2019. The sampling areas included 12 provinces municipalities in China and autonomous regions in total. Data were collected on weight, height, waist circumference, hip circumference and secondary sexual characteristics. The generalized additive model for location, scale, and shape (GAMLSS) was employed to establish percentile reference values and growth curves of height and weight for boys and girls aged 3-18 years. Wilcoxon rank sum test was applied to compare the P50 value of height and weight between children of each Tanner stage and children of the same age ignoring the different puberty phase. Results: The 3rd, 50th, and 97th percentile curves for height and weight for age were developed for boys and girls aged 3-18 years. The 3rd, 50th, and 97th percentile curves for age-specific height and age-specific weight for each puberty phase were developed for boys and girls. Compared with all children ignoring the different puberty phase, boys aged 9 and over and girls aged 7 and over who are at Tanner stage 1 showed shorter height and lighter weight than those of the same age group (all P<0.01), the difference ranges of height at P50 are -4.0 to -0.6 cm for boys, and -4.4 to 0.5 cm for girls; the difference ranges of weight are -4.8 to 0.4 kg for boys, and -4.0 to -0.3 kg for girls; children at Tanner stage 2 & 3 initially were taller and heavier than those of the same age group; and later grew shorter and lighter than those of the same age group, the two sets of curves cross over; boys aged 16 and under and girl aged under 14 who are at Tanner stage 4 were taller and heavier than those of the same age group (all P<0.01), the difference ranges of height at P50 are 0.2 to 10.0 cm for boys, and 0.2 to 9.4 cm for girls; the difference ranges of weight at P50 are 0.7 to 10.9 kg for boys, and 1.0 to 11.2 kg for girls, and the differences showed narrowing trend with age. Conclusion: The puberty phase specific growth curves of age-specific height and age-specific weight for boys and girls aged 3-18 years are established, it is useful for clinical work to evaluate physical development of children at different puberty phases.

[Analysis of four carnitine-acylcarnitine translocase deficiency cases caused by homozygous mutation of SLC25A20 c.199-10T> G].

Objective: To investigate the clinical, biochemical and genetic features of four carnitine-acylcarnitine translocase deficiency cases. Methods: Four cases diagnosed with carnitine-acylcarnitine translocase deficiency from Guangxi Maternal and Child Health Hospital were studied. DNA was extracted from dry blood filter for gene analysis. SLC25A20 gene analysis was performed in 1 case and the whole exon sequence analysis was performed in 3 cases. Results: Retrospective study on unrelated carnitine-acylcarnitine translocase deficiency patients, the age of onset was 1-28 d, the age of death were 1.5-30 d, main clinical features were hypoglycemia (4 cases), arrhythmia (2 cases), sudden death (2 cases). Biochemical test showed hypoglycemia (1.2-2.0 mmol/L) , elevated creatine kinase (955-8 361 U/L) and creatine kinase isozyme(199-360 U/L), normal or decreased free carnitine level (3.70-27.07 µmol/L) , elevated long-chain acylcarnitine (palmityl carnitine 1.85-14.84 µmol/L). The gene tests showed that all 4 cases carried SLC25A20 gene c.199-10T> G homozygous mutation, inherited from their parents. By analyzing the haplotype, we found that the mutation loci of C. 199-10T> G were all in the same haplotype. Conclusion: The c.199-10T> G mutation is an important molecular cause of carnitine-acylcarnitine translocase deficiency, which has relatively high frequency in Guangxi population, and is related to the founder effect.

Investigation on the properties of borate bonding agents: Ti6Al4V-porcelain bonding, chemical durability and preliminary cytotoxicity.

The purpose of this study was to investigate the properties of the borate bonding agents (BBAS) including chemical durability, biocompatibility and bonding characteristics of porcelain to Ti6Al4V. The bond strength was performed by the three-point bending test. And the chemical durability and ion release of BBAS were tested by chemical soaking and inductively coupled plasma optical emission spectrometry (ICP-OES), respectively. Moreover, cytotoxicity was evaluated by cell viability assay and cell adhesion using human osteosarcoma cells (MG-63) and cell counter kit-8 (CCK-8) assay. To investigate the influences of composition and microstructure changes on all the properties mentioned above, the 11B and 27Al spectra and infrared spectra of BBAS were measured by solid-state nuclear magnetic resonance (SSNMR) and Fourier transform infrared spectroscopy (FTIR), respectively. Combined with all these properties of BBAS, the optimal addition proportion of Al2O3 into BBAS is 20 mol%. The relative contents of [BO3], [BO4], [AlO4], [AlO5] and [AlO6] have great influences on these properties of BBAS. BBAS, possessing excellent chemical durability, good biocompatibility and low ion release and being an effective way to improve the Ti6Al4V-porcelain bond strength, have significant clinical potentials in porcelain fused to metal restorations.

[Study on handgrip strength of elderly ≥60 years old from longevity areas in China].

Objective: To assess the status of handgrip strength of elderly population from longevity areas in China, and to analyze the correlative factors of handgrip strength of elderly people. Methods: Data from Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2012 was used, from which1 967 participants aged ≥60 years old with valid data of grip strength value from 8 Chinese longevity areas were included. Information on demographics characteristic, life style and health status was collected using questionnaires. The handgrip strength of both left and right hands were measured by grip dynamometer. The different characteristics of group of participants with different grip strength were compared and then analyzed by adopting the Cumulative odds Logistic regression model to identify main factors associated with hand grip strength. Results: The P(50) (P(25)-P(50)) of hand grip strength of elderly people from the eight longevity areas was 20 (11-28) kg; The hand grip strength of males was 26 (18-34) kg, which was higher than that of females(14 (9-20) kg) (P<0.001). Cumulative odds Logistic regression model showed that the hand grip strength of females was lower than males, whose ß value (95%CI) was-1.22 (-1.43--1.00). The elderly who was at a higher age, smoking, drinking or with anemia, had a comparatively lower handgrip strength, whose ß (95%CI) value were separately-0.08(-0.09~-0.07),-0.29(-0.56~-0.02),-0.54(-0.80~-0.28), and-0.41(-0.62~-0.20). And the elderly who had a higher boby mass index, drinking tea and outdoor activities, had a comparatively higher handgrip strength, whose ß(95%CI) value were separately 0.28 (0.15-0.40), 0.25(0.03-0.47) and 0.51(0.30-0.71). Conclusion: Age and gender were the main correlative factors, lifestyles and physical conditions might also be correlative factors of hand grip strength of the elderly from longevity areas in China.

[Follow-up study of body mass index and risk of cognitive impairment among elderly adults aged ≥65 years old from longevity areas of China].

Objective: To discuss the relationship between body mass index (BMI) and cognitive impairment among elderly adults aged ≥65 years old from longevity areas of China. Methods: A total of 2 439 elderly adults from 8 longevity areas were included in our baseline survey by answering questionnaire and taking body measurements and blood biochemical examinations in 2012. In the follow-up study in 2014, we studied the cognitive impairment status among the 1 135 elderly adults aging ≥65 years old. Multivariate logistic regression model was used to analyze the relationship between BMI and cognitive impairment risk. Results: 113 participants were defined as cognitive impairment, with a positive rate at 10.0%. The positive rate in group of underweight, normal weight, and overweight and obese elderly were 22.2% (51/230), 7.5% (47/629), 5.4% (15/276). The rate of cognitive impairment in groups of low BMI (<19.7 kg/m(2)), middle BMI (19.7-23.1 kg/m(2)) and high BMI (>23.1 kg/m(2)) were separately 17.7% (66/372), 7.1% (27/379) and 5.2% (20/384) (P<0.001). Every 1.0 kg/m(2) increase in BMI, the risk of cognitive impairment would significantly decreased by 7% (RR(95%CI): 0.93(0.87-0.99)). Compared with participants with middle BMI level, the group of low BMI participants was associated with a significantly increased risk of cognitive impairment (RR (95% CI): 1.98(1.14-3.44)); while there was no significant association was observed in the high BMI group (RR(95%CI): 1.15(0.57-2.32)). Compared with elderly in normal weight, the elderly with under weight was in higher risk of cognitive impairment (RR (95%CI: 2.19(1.31-3.66)) and there was no significant association found between the elderly with overweight (RR(95%CI): 1.18(0.58-2.38)). Conclusion: Among the elderly ≥65 years old from longevity area, low BMI level and underweight were associated with the increased risk of cognitive impairment.

[Association between biomarkers and activities of daily living in the elderly ≥65 years old from longevity areas in China].

Objective: To explore the association between biomarkers and activities of daily living (ADL) in the elderly over 65 years old from longevity areas in China. Methods: A total of 2 439 people from 8 longevity areas were included in our baseline survey in 2012. Using questionnaires, body measurements, and blood biochemical examinations, information on demographics characteristic, life style, ADL, blood pressure and biomarkers were collected. Based on these six items of ADL (bathing, dressing, indoor activities, toileting, eating, bowel and bladder control), we constructed a dichotomous indicator for ADL. A respondent was defined as ADL disabled if any difficulty in one or more of the above six activities was reported. Information were collected in the follow-up in 2014 using the same questionnaires and examinations. We excluded information on the elderly who lacked ADL or biomarkers test results or with ADL disability at baseline study. Finally 938 elderly people over 65 years old were included in this analysis. Multivariate logistic regression model was used to analyze the influence factors of ADL disability. Results: During the 2-year follow-up, 100 (10.7%) participants developed into ADL disability, with a rate at 10.7%. Multivariate logistic regression analysis indicated that each year increase in age or each 1 mmHg (1 mmHg=0.133 kPa) increase in systolic blood pressure (SBP) would cause the risk of ADL disability to increase 9% or 1%, whose OR (95%CI) were separately 1.09 (1.06-1.12), 1.01 (1.00-1.02). Han nationality or cognitive impairment increased the risk of ADL disability, whose OR (95%CI) values were separately 4.90 (1.13-21.24), 2.47 (1.44-4.25), while increased lymphocyte count (>1.60×10(9)/L), being married, or participating in recreational activities decreased the risk of ADL disability, whose OR (95%CI) values were separately 0.51 (0.31-0.82), 0.52 (0.28-0.96), 0.43 (0.23-0.80). Conclusion: In the elderly elevated lymphocyte count was associated with lower risk of ADL disability. In addition, incresed age, increased SBP, unmarried, Han nationality or cognitive impairment were associated with the increasing risk of ADL disability in older people, while participating in recreational activities would reduce the risk.

[Relationship between the successful aging and survival status among the elderly from longevity areas in China].

Objective: To explore the relationship between successful aging (SA) index and the survival status among elderly from longevity areas of China. Methods: A total of 2 296 old people aged ≥65 years old from 8 longevity areas were enrolled in our baseline survey in 2012. The information of demographics characteristic, life style, self-assessed health and mood or emotional state, cognitive function, abilities of daily living and physical activity were collected by questionnaire. There were 891 SA people in total, whose SA score was 4-5. 891 SA and 1 396 non-SA participated in the follow-up study in 2014. Finally, 860 SA and non-SA people were matched by orientation analysis. A Cox proportional hazards model was used to explore the relationship between successful aging index and survival status. Results: After 2 years of follow-up, a total of 1 442 elderly survived, with an average baseline age at (83.69±10.81) years old and 278 elderly people died, with an average baseline age at (93.41±9.05) years old. The mortality rate was 16.16% (278/1 720) in total, and it was 13.14% (113/860) in SA group, which was lower than it in non-SA group (19.19%, 165/860), and the difference was statistically significant (P=0.001). The analysis of the multivariate Cox regression showed that SA was the protective factor of the survival of the elderly after age and sex adjusted. Compared to the non-SA group, the risk of mortality rate in SA group decreased by 38%, the HR (95% CI) was 0.62 (0.49-0.79). Conclusion: The mortality rate in the SA group was low in the longevity areas in China; compared with non-SA group, the death rate in SA group reduced by 38%.

[A perspective cohort study on influence factors of survival outcome among the elderly aged ≥80 years old from longevity areas in China].

Objective: To investigate the influence factors of survival outcome among elderly aged ≥80 years old. Methods: In baseline survey in 2009, 930 participants aged ≥80 years old were enrolled from 7 longevity areas, to collect the information of socioeconomic factors, life style, cognitive function, activities of daily living and diseases, as well as physical examination to test biomarkers of blood and urine. The survival status was followed up at 2012 and 2014 survey. Stepwise Cox proportional hazards models were used to screen influence factors of 5-year survival. Results: During 5 years of follow-up, 571 participants died, 133 participants were lost to follow up, and the all-cause mortality was 63.4%. In stepwise Cox proportional hazards models, male, unmarried, self-reported poor life quality, disability in daily life, cognitive impairment, cardiovascular and cerebrovascular diseases, chronic kidney diseases were risk factors for elderly survival outcome, with the HR (95%CI) at 1.75 (1.40-2.12), 1.49 (1.10-2.03), 1.40 (1.16-1.69), 1.37 (1.11-1.70), 1.51 (1.22-1.88), 1.62 (1.18-2.23) and 1.48 (1.23-1.77) respectively. Each 1 year increase in age corresponded to 4% increase in mortality risk (HR (95%CI)=1.04 (1.02-1.05)); each 1 kg/m(2) increase in BMI corresponded to 5% increase in mortality risk (HR (95%CI)=0.95 (0.93-0.98)); each 1.0×10(9)/L increase in total lymphocyte count (TLC) corresponded to 13% increase in mortality risk (HR (95%CI)=0.87 (0.76-0.99)). Additionally, the mortality risk decreased 19% (HR (95%CI)=0.81 (0.66-0.98)) in participants with regularly physical exercise compared to those without; and the mortality risk decreased 41% (HR (95% CI)=0.59 (0.40-0.88)) in participants with elevated triglycerides (TG, ≥2.26 mmol/L) compared to those without. Conclusion: In Chinese longevity areas, some nutritional and immune indices such as relatively higher level of BMI, TLC and TG were independent protective factors for 5-year survival outcome, which was different from general adults and younger elderly.

[Association between serum albumin and cognitive performance in elderly Chinese].

Objective: To explore association between serum albumin level and cognitive performance in elderly Chinese. Methods: All the subjects aged ≥65 years in the 8 longevity areas in Chinese longitudinal health longevity survey (CLHLS) were invited to participate the biomedical indepth CLHLS study, information about subjects' demographic characteristics, lifestyle, prevalence of diseases and health status was collected through household-interview. The cognitive performance was assessed with Mini Mental State Evaluation (MMSE) scale. Health examination was conducted by medical personnel and fasting venous blood samples were collected to detect the levels of triglycerides, total cholesterol, fasting glucose, creatine and blood albumin. MMSE score was compared and the trend was analyzed with generalized linear model. Association between albumin concentration and cognitive impairment was analyzed by logistic regression model. Results: Generalized linear model showed that adjusted MMSE score increased from 23.22 in the lowest quartile group to 25.07 in the highest quartile group (P for linear trend <0.001). Logistic regression analysis results showed that the higher albumin level was associated with the lower risk of cognitive impairment (P< 0.001), the OR decreased linearly with the increasing level of albumin (P<0.01), with the OR (95%CI) for the lower, higher and highest quartile groups was 0.64(0.45-0.91), 0.60(0.40-0.89) and 0.43(0.27-0.69), respectively, compared with the lowest quartile group. Conclusion: High level of serum albumin was associated with low risk of cognitive impairment.

[Follow-up study on the effects of lipid ratios on all-cause mortality among elderly adults in longevity areas of China].

OBJECTIVE: To explore the association between lipid ratios and all-cause mortality among elderly adults aged 80 years and older living in longevity areas of China. METHODS: A total of 874 participants in the Chinese Longitudinal Healthy Longevity Survey during June 2009 were included in our baseline survey. Lipid concentrations were measured and lipid ratios including LDL-C/HDL-C, TG/HDL-C, and atherosclerosis index (AI) were calculated at baseline, and the information on questionnaires, body measurement, and blood biochemical profiles was collected. Survival time and survival status were followed up in August 2012. Subjects were stratified into three groups (low, middle and high) by tertiles of lipid ratios. All-cause mortality was calculated. Cox regression models were used to assess the association of lipid ratios with mortality. RESULTS: During 38 months of follow-up, a total of 427 participants had died, 378 participants survived, and 69 participants were lost to follow-up; overall mortality was 50.5%. For these participants, P50 (P25-P75) values for LDL-C/HDL-C were 1.68 (1.22-2.05), 1.85 (1.34-2.16), and 1.78 (1.33-2.08), respectively (H=6.93, P=0.025); values for TG/HDL-C were 1.00 (0.79-1.34), 1.20 (0.97-1.53), and 1.23 (0.95-1.72), respectively (H=9.18, P=0.008). AIs were 2.12 (1.72-2.61), 2.27 (1.84-2.75), and 2.13 (1.80-2.58), respectively (H=6.37, P=0.041). Values for 38-month all-cause mortality were 53.1%, 50.0%, and 44.0% among participants with low, middle, and high LDL-C/HDL-C ratios (<1.39, 1.39-1.92, ≥1.92), respectively (χ(2)=7.54, P=0.024); these values were 54.8%, 46.4%, and 45.3% among participants with low, middle, and high AIs (<1.83, 1.83-2.39, ≥2.39), respectively (χ(2)=6.67, P=0.035). Each 1 unit increase of LDL-C/HDL-C, TG/HDL-C , and AI corresponded to a 17%, 15%, and 13% decrease in 38-month all-cause mortality, respectively; adjusted HRs were 0.83 (0.72-0.97), 0.85 (0.74-0.99), and 0.87 (0.76-0.99), respectively. Compared with participants who had low LDL-C/HDL-C ratios, high ratios were associated with lower risk of mortality (HR 0.88; (95% CI: 0.78-0.99)). Compared with low AIs, middle and high values were associated with lower risk of mortality HRs (95%CI) were 0.84 (0.72-0.98) and 0.87 (0.78-0.98);respectively. CONCLUSION: LDL-C/HDL-C, TG/HDL-C, and AI were negatively associated with all-cause mortality among elderly adults aged 80 years and older living in longevity areas of China.

[Association between oxygen saturation and cognitive function in older adults from longevity areas in China].

OBJECTIVE: To explore the relationship between oxygen saturation (SpO2) and cognitive function in older adults from longevity areas in China. METHODS: A total of 2 285 participants aged ≥65 years according to the 2012 Chinese Longitudinal Healthy Longevity Survey were included in this study. Among them, 1 739 participants aged 65-99 years were randomly selected, and 546 participants aged ≥100 years were totally involved. A standardized questionaire was used to collect the information of demographic characteristics, life styles, disease history, etc. Cognitive function was evaluated using the Mini Mental State Examination Scale. Arterial oxygen saturation and heart rate were measured by pulse oximetry. Differences in cognitive function between the low SpO2 group (<0.94) and normal SpO2 group (≥0.94) were analyzed, and logistic regression models were used to analyze the relationship between SpO2 and cognitive function. RESULTS: The total score of cognitive function was 22.6±9.7 for the 1 922 participants in the normal SpO2 group, and 18.8 ± 11.0 for the 363 participants in the low SpO2 group (t=6.11, P<0.001). The proportion of cognitive impairment in the low SpO2 group was 36.6% (n=133), and 22.9% (n=441) in the normal SpO2 group (χ(2)=30.44, P<0.001). RESULTS from stepwise logistic regression analysis showed that the risk of cognitive impairment increased with each year of increased age (OR 1.07; (95% CI: 1.05-1.09), P<0.001). Low SpO2, vision disorders, impaired activities of daily living, dyslipidemia, unmarried status, and lack of exercise were also associated with increased risk of cognitive impairment (OR 1.64; (95% CI: 1.11-2.43), OR 1.73; (95% CI: 1.27-2.35), OR 3.54; (95% CI: 2.62-4.79), OR 1.38; (95% CI: 1.02-1.86), OR 2.05; (95% CI: 1.34-3.13), OR 1.83; (95% CI: 1.13-2.97), respectively, P<0.05). Stratified analysis by age group showed that the association between SpO2 and cognitive impairment was most significant in participants aged ≥90 years (OR 1.58; (95% CI: 1.09-2.28), P=0.016). CONCLUSION: Low oxygen saturation was associated with higher risk of cognitive impairment in our population of elderly adults.

[Association between the hypersensitive C-reactive protein and activities of daily living among elderly adults in longevity areas of China].

OBJECTIVE: To explore the association between the hypersensitive C-reactive protein (hs-CRP) and activities of daily living (ADL) in elderly adults in longevity areas of China. METHODS: This analysis included data on 2 352 adults aged ≥65 years from eight longevity areas from the Chinese Longitudinal Healthy Longevity Survey in 2012. We excluded information on adults who lacked ADL or blood test data; the final study population comprised 2 227 elderly adults. Using questionnaires, body measurement, and blood biochemical examination, information on demographic characteristics, lifestyle, ADL, blood pressure, blood lipids, and biomarkers was collected. Study participants who were able to independently carry out the six kinds of activities of daily living (bathing, dressing, indoor activities, toileting, eating, bowel and bladder control) comprised the normal ADL group, and those who could not were included in the impaired ADL group. A multivariate logistic regression model was used to analyze factors influencing ADL impairment. RESULTS: Among the 2 227 participants, 1 674 (75.2%) were included in the normal ADL group and 553 (24.8%) in the impaired ADL group. Among all participants. Adults in the normal ADL group had lower hs-CRP levels (P50 (P25-P75)=0.88; 0.38-2.29 mg/L) than those in the impaired ADL group (1.27; 0.47-4.28 mg/L); (Z=- 4.71, P<0.001). Participants in the normal ADL group also had lower hs-CRP elevation rates (214; 12.8%) than those in the impaired ADL group (125; 22.6%); (χ(2)= 31.06, P<0.001). Multivariate logistic regression analysis indicated that each age increase of one year increased the risk of ADL impairment by 1.08 times (OR 1.08 (95%CI: 1.07-1.10); P<0.001). Participants with increased hs-CRP levels, those of Han nationality, and participants with a previous history of stroke had a higher risk of ADL impairment (OR(95% CI) values were 1.42(1.04-1.94), 1.87(1.13-3.08), 2.81(1.87-4.23); P<0.05). Elderly adults who participated in recreational activities had a lower risk of impaired ADL (OR 0.29 (95%CI: 0.22-0.38); P<0.001). CONCLUSION: In this study among elderly adults living in longevity areas of China, hs-CRP levels were related to ADL and elevated hs-CRP was associated with a higher risk of ADL impairment.

[Management of subglottic stenosis in children with endoscopic balloon dilation].

OBJECTIVE: To evaluate the efficacy of endoscopic balloon dilation for subglottic stenosis. METHODS: The clinical outcomes of 9 pediatric patients treated with balloon dilation were retrospectively analyzed. There were 8 male and 1 female. Their age ranged from 7 months to 7 years (mean 2.5 years). The degree of stenosis was classified according to Myer-Cotton classification as follows: grade Ⅱ (n=7) and grade Ⅲ (n=2). The causes of the stenosis were postintubation lesions (n=8) and laryngeal penetrating trauma (n=1). RESULTS: The patients had undergone 1 to 3 dilations with an average of 1.8 procedures per patient. Six (66.7%) patients were decannulated. Among them, 4(44.4%) were decannulated after one dilation procedure. Pneumothoraces occurred in 2 children postoperatively. CONCLUSION: Endoscopic balloon dilation is an effective, relatively safe and minimally invasive surgical method for patients with low-grade subglottic stenosis.

[Segmental tracheal resection and anastomosis for the treatment of cicatricial stenosis in cervical tracheal].

OBJECTIVE: To evaluate the efficacy of segmental tracheal resection with end-to-end anastomosis for cicatricial cervical tracheal stenosis. METHODS: The clinical outcomes of 40 patients treated with tracheal resection were retrospectively reviewed. There were 28 male patients and 12 female patients with the age ranged from 6 to 64 years (mean 33.7 years). The degree of stenosis was classified according to Myer-Cotton classification as follows: grade Ⅱ (n=7), grade Ⅲ (n=22) and grade Ⅳ (n=11). The stenosis extension ranged from 1.0 to 4.3 cm (mean 2.5 cm). The causes of the stenosis were postintubation (n=33), cervical trauma (n=6) and resection of tracheal neoplasm (n=1). RESULTS: Thirty-four(85.0%) patients were decannulated and 6 failed. Of the 6 patients failed, 4 were decannulated after reoperation with the sternohyoid myocutaneous flap or thyroid alar cartilage graft. Complications occurred in 10 patients. In 8 patients granulation tissues formed at the site of the tracheal anastomosis, which needed endoscopic resction, and in 2 patients anastomosic dehiscence occurred. No injury to recurrent laryngeal nerve or trachoesophageal fistula occurred. CONCLUSION: Segmental tracheal resection with end-to-end anastomosis is an effective surgical method for tracheal stenosis, which has a higher successful rate for primary operation and shorter therapeutic period.

Structural determinants in the second intracellular loop of the human cannabinoid CB1 receptor mediate selective coupling to G(s) and G(i).

BACKGROUND AND PURPOSE: The cannabinoid CB(1) receptor is primarily thought to be functionally coupled to the G(i) form of G proteins, through which it negatively regulates cAMP accumulation. Here, we investigated the dual coupling properties of CB(1) receptors and characterized the structural determinants that mediate selective coupling to G(s) and G(i). EXPERIMENTAL APPROACH: A cAMP-response element reporter gene system was employed to quantitatively analyze cAMP change. CB(1)/CB(2) receptor chimeras and site-directed mutagenesis combined with functional assays and computer modelling were used to determine the structural determinants mediating selective coupling to G(s) and G(i). KEY RESULTS: CB(1) receptors could couple to both G(s)-mediated cAMP accumulation and G(i)-induced activation of ERK1/2 and Ca(2+) mobilization, whereas CB(2) receptors selectively coupled to G(i) and inhibited cAMP production. Using CB(1)/CB(2) chimeric receptors, the second intracellular loop (ICL2) of the CB(1) receptor was identified as primarily responsible for mediating G(s) and G(i) coupling specificity. Furthermore, mutation of Leu-222 in ICL2 to either Ala or Pro switched G protein coupling from G(s) to G(i), while to Ile or Val led to balanced coupling of the mutant receptor with G(s) and G(i) . CONCLUSIONS AND IMPLICATIONS: The ICL2 of CB(1) receptors and in particular Leu-222, which resides within a highly conserved DRY(X)(5) PL motif, played a critical role in G(s) and G(i) protein coupling and specificity. Our studies provide new insight into the mechanisms governing the coupling of CB(1) receptors to G proteins and cannabinoid-induced tolerance.

Melting scenario in metallic clusters.

The isothermal Brownian-type molecular dynamics simulation has been applied to study the melting behavior of bimetallic clusters. It was found that the specific heat and Lindermann-like parameter customarily used in bulk system to describe solid-liquid transition show incongruity in the predicted melting temperature T(melt). The underlying mechanisms that lead to the incompatibility of T(melt) separately deduced from these two quantities were analyzed further. To gain insight into the melting behavior, we calculated in addition the velocity autocorrelation function and its Fourier transform, the power spectrum, and extracted from them the T(melt). It appears that the T(melt) inferred from the latter quantities is closer to that deduced from the principal peak position of specific heat. Two bimetallic clusters, namely, Ag(1)Cu(13) and Au(1)Cu(13), were selected for a thorough investigation. In the context of cluster morphology, we scrutinized the atomic distributions of Ag(1)Cu(13), Au(1)Cu(13), and Cu(14) and effected a comparative study between a bimetallic cluster and a pure cluster so as to learn from comparison the differences in the thermal reaction of atoms, in particular, the impurity atom in the bimetallic cluster. On analyzing the dynamical data, we observed at a lower temperature (T<

[Formation of the allogeneic tissue engineered cartilage using injectable biomaterial].

OBJECTIVE: To study the feasibility of the formation of allogeneic tissue-engineered cartilage of certain shape in immunocompetent animal using the injectable biomaterial. METHODS: Fresh newborn rabbits' articular cartilages were obtained under sterile condition (< 6 hours after death) and incubated in the sterile 0.3% type II collagenase solution. After digestion of 8 to 12 hours, the solution was filtered through a 150 micron nylon mesh and centrifuged, then the chondrocytes were washed twice with phosphate buffered saline (PBS) and mixed with the biomaterial to create a final cell density of 5 x 10(7)/ml. The cell-biomaterial admixture was injected into rabbits subcutaneously 0.3 ml each point while we drew the needle back in order to form the neocartilage in the shape of cudgel, and the control groups were injected with only the biomaterial or the suspension of chondrocytes with the density of 5 x 10(7)/ml. After 4, 6, 8 and 12 weeks, the neocartilages were harvested to analyze. RESULTS: The new nodes could be touched subcutaneously after 2 weeks. In the sections of the samples harvested after 4 weeks, it was found that the matrix secreted and the collagen formed. After 6 weeks and later than that, the neocartilages were mature and the biomaterial was almost completely degraded. The cudgel-shaped samples of neocartilage could be formed by injection. In the experiment group, there was no obvious immune rejection response. On the contrary, there were no neocartilage formed in the control group. CONCLUSION: The injectable biomaterial is a relatively ideal biomaterial for tissue engineering, and it is feasible to form allogeneic tissue engineered cartilage of certain shape by injection in an immunocompetent animal.

Comparison of the effects of immunosuppressive factors from newly established colon carcinoma cell cultures on human lymphocyte proliferation and cytokine secretion.

Tumor cells may influence the host's immune reactivity by the production of immunosuppressive factors (ISFs). In this study, the effects of ISFs derived from nine polyclonal colorectal carcinoma (CRC) cell lines on PHA-induced lymphocyte proliferation and cytokine secretion was investigated. We found that most of the culture supernatants (8/9) from CRC cell lines contained ISFs, which inhibited T cell proliferation to a variable degree in a dose-dependent manner. Comparison of T cell proliferation in the presence or absence of monocytes showed that monocytes can modulate the effects of tumor-derived ISFs on lymphocyte function. In addition, exposure of activated PBMC to the tumor cell supernatants resulted in an altered secretion of cytokines by these cells, i.e. the secretion of IFN-gamma was generally reduced while the secretion of IL-1beta, IL-2 and TNF-alpha was little affected. We further investigated the supernatants' inhibitory effects on PBMC in respect to the production of prostaglandin E(2) (PGE(2)). It was found that PGE(2) was secreted by all tumor cell cultures. Therefore this substance is probably involved in the immunosuppression in vivo. However, the secreted PGE(2) was shown not to be solely responsible for the observed suppression of lymphocyte proliferation in vitro. Our results suggest that the secretion of ISF is a common property of CRCs as demonstrated with newly established CRC cell cultures, and therefore this may also be an important immune escape mechanism of colonic carcinomas in vivo.

Biliary glycoprotein (CD66a), a cell adhesion molecule of the immunoglobulin superfamily, on human lymphocytes: structure, expression and involvement in T cell activation.

The biliary glycoproteins (BGP or CD66a), a group of different splice variants of a single gene, are members of the carcinoembryonic antigen family and the immunoglobulin superfamily. Recently, we detected CD66a on IL-2 activated lymphocytes. In this study we characterized the structure and the expression pattern of BGP on human lymphocytes and investigated its role in T cell activation. Lymphocytes express 2 of the 13 known splice variants, i.e. BGPa and BGPb, which are glycosylated in a lymphocyte-specific manner. Both BGPa and BGPb have the long cytoplasmic tail, which contains two immunoreceptor tyrosine-based inhibitory motif (ITIM)-like motifs, but differ in their extracellular region containing 4 and 3 immunoglobulin-like domains, respectively. On PBL BGP is expressed in small amounts only on B cells and Th cells. Stimulation with IL-2 leads to a strong up-regulation of BGP by these cells, and induces de novo BGP expression on gammabeta T cells, CD8+ and CD56+ cells, but not on CD16+ lymphocytes. This up-regulation of BGP seems to be part of the physiological process of T cell activation, since stimulation with anti-CD3 mAb is sufficient to induce BGP up-regulation. Based on the presence of the two ITIM-like motifs, one may expect that BGP inhibits T cell activation, but surprisingly, engagement of BGP enhances the proliferation of anti-CD3-stimulated T cells.