Pulse pressure is associated with decline in physical function in older adults.

OBJECTIVES: This study examined the associations between pulse pressure, hypertension, and the decline in physical function in a prospective framework. STUDY DESIGN: The Healthy Aging Longitudinal Study tracked a group of Taiwanese adults aged 55 or more over an average of 6.19 years to assess pulse pressure and decline in physical function, including in handgrip strength, gait speed, and 6-min walking distance, at baseline (2009-2013) and in the second phase of assessments (2013-2020). MAIN OUTCOME MEASURES: Pulse pressure was calculated as the difference between systolic and diastolic blood pressure values. Weakness, slowness, and low endurance were defined as decreases of ≥0.23 m/s (one standard deviation) in gait speed, ≥5.08 kg in handgrip strength, and ≥ 57.73 m in a 6-min walk, as determined from baseline to the second phase of assessment. Linear and logistic regressions were employed to evaluate the associations between pulse pressure, hypertension, and decline in physical function. RESULTS: Baseline pulse pressure was associated with future handgrip strength (beta = -0.017, p = 0.0362), gait speed (beta = -0.001, p < 0.0001), and 6-min walking distance (beta = -0.470, p < 0001). In multivariable models, only handgrip strength (beta = -0.016, p = 0.0135) and walking speed (beta = -0.001, p = 0.0042) remained significantly associated with future pulse pressure. Older adults with high systolic blood pressure (≥140 mmHg) and elevated pulse pressure (≥60 mmHg) exhibited a significantly increased risk of weakness (odds ratio: 1.30, 95 % confidence interval: 1.08-1.58), slowness (1.29, 1.04-1.59), and diminished endurance (1.25, 1.04-1.50) compared with the reference group, who exhibited systolic blood pressure of <140 mmHg and pulse pressure of <60 mmHg. CONCLUSIONS: Among older adults, pulse pressure is associated with a decline in physical function, especially in terms of strength and locomotion.

[Population characteristics and impact on heart rate variability, heart rate and blood pressure of passive smoking].

OBJECTIVE: To investigate the basic characteristics of passive smoking population, and the impact of passive smoking on heart rate variability, heart rate and blood pressure. METHODS: Eighty-six passive smokers [mean age: (52.4 ± 7.6) years] were recruited from patients and their relatives who visited cardiovascular outpatient department and excluded structural heart disease between June 2010 and June 2012, 80 normal subjects who were not exposed to smoking served as controls. Questionnaire survey, 24 hours ambulatory electrocardiogram examination and blood pressure measurement were performed in all recruited subjects. RESULTS: (1) Non-marriage rate [18.60% (16/86) vs. 3.75% (3/80), P < 0.01] was significantly higher while education level were significantly lower in passive smoking group than in control group. Passive smokers were more likely service industry workers [29.07% (25/86) vs. 15.00% (12/80), P < 0.05] and had longer daily working time [(7.56 ± 1.24) h vs. (6.02 ± 0.96) h, P < 0.01], and were less likely to be professional technology industry employers [20.93% (18/86) vs. 36.25% (29/80), P < 0.05] and managers [13.95% (12/86) vs. 38.75% (31/80), P < 0.01] compared to controls. The main place of passive smoking was workplace (67.44%, 58/86), entertainment venues (63.95%,55/86), restaurants (48.84%, 42/86). (2) Standard of the normal sinus RR intervals (SDNN), the normal consecutive sinus RR interval difference between the root-mean-square (rMSSD) and adjacent the difference between the RR interval>50 ms the number of share the percentage (PNN50) were significantly lower in passive smoking group than in the control group (all P < 0.05). Every 5 min average of the standard deviation of sinus RR cycle (SDNN index) and 24 h every 5 min sinus RR interval mean standard deviation (SDANN) were similar between the 2 groups (all P > 0.05). Ultra-low-frequency power (VLF), low frequency power (LF), high frequency power (HF) and LF/HF were significantly lower in passive smoking group than in the control group (all P < 0.01). (3) Heart rate and diastolic blood pressure were significantly higher in passive smoking group than in control group (all P < 0.05) while systolic blood pressure was similar between the 2 groups (P > 0.05). CONCLUSIONS: Marriage status, education level, profession and daily working time are independent determinants for passive smoking. Passive smoking mainly occurred in the workplace, entertainment venues and restaurants. Passive smoking is linked with reduced heart rate variability, increased 24 h average heart rate and diastolic blood pressure.

[Effect of the smoking cessation services in the out-patient department for patients with coronary heart disease].

OBJECTIVE: To evaluate the effects and clinical prognosis of out-patient department-based smoking cessation services for coronary heart disease (CHD) patients. METHODS: A total of 140 smoking patients diagnosed with coronary heart disease in our cardiovascular department were randomly divided into the intensive smoking cessation clinic follow-up group (intervention group, patients were informed on the importance and methods to quit smoking at the first visit and reminded for that at months interval for 6 months, n = 70) and the conventional treatment group (control group, n = 70). After 6 months, the smoking status, cardiovascular event rates, drug usage, out-patient medical costs and quality of life were compared between the two groups. RESULTS: Age, gender, concomitant diseases, drug usage were similar between the two groups at baseline (all P > 0.05). After 6 months, smoking quit rate [34.2% (24/70) vs. 5.7% (4/70), P < 0.01], drug use rates: lipid-lowering drugs [95.3% (67/70) vs. 80.4% (56/70)], ß blockers [82.4% (57/70) vs. 41.3% (28/70)], and ACEI/ARB [61.4% (43/70) vs. 34.4% (24/70)] were significantly higher in the intervention group than in the control group, while total cardiovascular event rates [21.4% (15/70) vs. 47.1% (33/70), P < 0.01] and out-patient medical costs (3789.3 RMB vs. 4984.2 RMB, P < 0.01) were significantly lower in the intervention group than in the control group. The quality of life scores derived from MYO health survey questionnaire was significantly higher in the intervention group than in the control group (P < 0.01). The top three reasons responsible for continuous smoking for all patients failed to quit smoking were: (1) others smoked more than me and still alive and healthy [90.3% (56/62)]; (2) smoking helped me to keep relaxed and reduce trouble in daily work and life [70.9% (44/62)]; (3) smoking was essential while chatting and drinking with friends [66.1% (41/62)]. The overall satisfactory rate to this smoking cessation program was 42.8% and the satisfactory rate was up to 50.0% by patients. CONCLUSIONS: Intensive outpatient smoking cessation follow-up program can significantly improve the smoking cessation rates, the guideline drug use rate and the quality of life while reduce medical costs for coronary heart disease patients.

[Types and risk factors of arrhythmia on young patients with acute coronary syndrome in Henan province].

OBJECTIVE: The types and risk factors of arrhythmia were analyzed on acute coronary syndrome (ACS) patients under the age of 44 years who were hospitalized in Henan province between September 2009 to June 2012. METHODS: Medical records of eligible patients were obtained from the information system of the First Affiliated Hospital of Zhengzhou University teleconsultation information center. Middle aged and elderly ACS patients who were hospitalized at the same period served as controls. Data on arrhythmia types, blood pressure, thyroid disease, respiratory sleep apnea syndrome, smoking history, history of alcohol consumption, eating habits, family history of early-onset arrhythmia, laboratory tests were analyzed. RESULTS: (1) Arrhythmia was detected in 110 out of young ACS patients (55%), which was significantly lower than that in the elderly ACS patients (71.05%, P < 0.01). (2) The top three arrhythmias in young ACS patients were: sinus tachycardia (30.50%), the premature ventricular contractions (19.00%), atrial flutter/atrial fibrillation (16.50%). Incidence of sinus tachycardia, atrial flutter/atrial fibrillation were significantly higher while incidence of ventricular tachycardia, ventricular fibrillation, paroxysmal supraventricular tachycardia were significantly lower in young ACS patients than in middle-aged ACS patients (all P < 0.05). The incidence of sinus tachycardia was higher while incidence of ventricular premature accelerated ventricular spontaneous cardiac rhythm, ventricular tachycardia, ventricular fibrillation, non-paroxysmal supraventricular tachycardia, atrial flutter/atrial fibrillation, paroxysmal supraventricular tachycardia, sinus bradycardia, nodal escape, atrioventricular block were significantly lower in young ACS patients than in elderly ACS patients (all P < 0.05). (3) Body mass index, incidence of smoking, coronary three-vessel disease, drinking, eating salty foods, thyroid dysfunction, sleep apnea were significantly higher in youth ACS patients with arrhythmia than in young ACS patients without arrhythmia (all P < 0. 05). (4) Logistic regression analysis found that number of diseased coronary vessels (OR = 24.293), smoking (OR = 1.112) and alcohol consumption (OR = 1.039) were independent risk factor for developing arrhythmia in young ACS patients from Henan province. CONCLUSIONS: The main types of arrhythmia are sinus tachycardia, premature ventricular contractions, atrial flutter/atrial fibrillation and the major risk factors related to the arrhythmia are number of diseased coronary vessels, smoking and alcohol consumption in young ACS patients from Henan province.

Central obesity and elevated blood pressure in middle life are associated with physical and cognitive impairment in later life: A retrospective design with repeated measures.

BACKGROUND AND AIMS: Physical and cognitive function decline indicates the prestage of disability and is associated with mortality among older adults. We investigated the association of metabolic disorders in midlife with physical and cognitive function decline in later life in a retrospective cohort. MATERIAL AND METHODS: A total of 618 older adults aged ≥60 years in wave-6 (2014-2017) were enrolled in the Cardiovascular Disease Risk Factor Two-Township Study to evaluate physical (hand grip strength and 4-m walking speed) and cognitive function (Mine-Mental State Examination [MMSE] score). Repeated metabolic disorder measures in wave-2, wave-3, and wave-5 were obtained to identify three trajectory pattern groups according to each metabolic disorder through group-based trajectory modeling. Linear and logistic regressions were conducted to investigate the association of metabolic disorders in middle life with physical and cognitive function decline in later life. RESULTS: The prevalence rates of a weak hand grip (<28 kg for men and <18 kg for women), slow walking speed (<0.8 m/s), and poor cognitive function (MMSE <25) were 24.43 %, 16.83 % and 10.5 %, respectively, among the older adults. In the retrospective cohort with 15-year follow-up, those with a waist circumference of ≥95 cm for men and ≥85 cm for women in middle life exhibited a significantly weak hand grip (odds ratio: 2.78 [95 % confidence interval: 1.26, 6.11]) and slow walking speed (2.26 [1.15, 4.43]) in later life compared with those with a smaller waist circumference (<85 cm for men and <75 cm for women). Elevated blood pressure (systolic blood pressure [BP] ≥130 mmHg or diastolic BP ≥80 mmHg) was significantly associated with a higher risk of cognitive function decline in later life. Furthermore, the high-trajectory and middle-trajectory groups' body mass index (3.17 [1.25, 8.04] and 2.27 [1.28, 4.00], respectively) and waist circumference (4.39 [2.07, 9.31] and 2.54 [1.39, 4.67], respectively) were significantly associated with a weak hand grip and slow walking speed, respectively, compared with those of the low-trajectory group. The high-trajectory diastolic BP group was significantly associated with a higher risk of cognitive function decline compared with the low-trajectory diastolic BP group. CONCLUSION: Waist circumference and BP in middle life were associated with physical function decline and poor cognitive function in later life. The management of central obesity and BP in midlife may slow the decline of physical and cognitive function in later life.

[Quality of life change and its influencing factors in patients with acute coronary syndrome after drug-eluting stent implantation].

OBJECTIVE: To prospectively evaluate the change of quality of life in patients with acute coronary syndrome following percutaneous coronary intervention (PCI) with drug-eluting stents and explore the influencing factors of quality of life. METHODS: There hundred and thirty four consecutive patients with acute coronary syndrome receiving drug-eluting stents implantation between September 2008 and December 2009 were enrolled. Of them, two hundred and ninety three patients completed 36-item short form health survey at baseline and 6 months after PCI procedure. Change of quality of life and influencing factors on quality of life were analyzed. RESULTS: Compared with baseline, quality of life improved significantly after PCI in terms of both physical component summary and mental component summary [ (51.07 ± 20.39) scores vs. (61.69 ± 19.73) scores and (63.27 ± 20.00) scores vs. (68.81 ± 18.71) scores, respectively; all P < 0.01]. Multiple linear regression analysis showed that female, diabetes and ST-segment elevation myocardial infarction were independent predictors of physical component summary improvements post PCI (ß values were -0.310, -3.880 and 1.302, respectively; P < 0.05 or P < 0.01). Previous PCI and diabetes were independent predictors of mental component summary improvements post PCI (ß values were -1.483 and -2.790, respectively; all P < 0.01). CONCLUSIONS: Quality of life of acute coronary syndrome patients is significantly improved at 6 months after drug-eluting stents implantation. The predictors of physical quality of life improvement are female, diabetes, and ST-segment elevation myocardial infarction. Predictors of mental quality of life improvement are previous PCI and diabetes.

Education level may modify the association between cardiac index and cognitive function among elders with normal ejection function.

Background: Lower cardiac index (CI) in elders has been associated with incident dementia, and higher CI has protectively effect with brain aging. In the present study, we investigated the modulating effects of education level and arterial stiffness on the association between CI and cognitive function among older adults. Methods: A total of 723 elders (≥60 years, 50.1% women) with normal left ventricular ejection fraction (≥50%) were identified from the Cardiovascular Diseases Risk Factor Two-Township Study. CI was calculated from the Doppler-derived stroke volume. We evaluated arterial stiffness by measuring carotid-femoral pulse wave velocity (CFPWV) and global cognitive function by using the Mini-Mental Short Examination (MMSE). Education level was determined by years of formal education. Results: In linear regression analysis adjusting for age, sex, formal years of education, and CFPWV, CI was significantly positively associated with MMSE (BETA=0.344±0.130, P = 0.0082). In logistic regression analysis adjusting for age, sex, formal years of education, and CFPWV, subjects with a CI≥75 percentile had a significantly lower risk of low MMSE (<26) (OR = 0.495, 95% CI = 0.274-0.896, P = 0.02). In subgroup analysis, higher CI was significantly associated with higher MMSE and lower risk of low MMSE only in elders with ≤ 9 years of formal education. Causal mediation analysis suggests that higher CI maintains higher MMSE in elders with lower education levels whereas higher CFPWV causes lower MMSE in all the elders. Conclusion: In elders with normal ejection fraction, a higher CI was associated with a lower risk of cognitive function impairment, independent of arterial stiffness, mainly in subjects with a lower education level and possibly a smaller cognitive reserve.

[Association between systemic inflammation and autoimmunity parameters and plasma lipid in patients with rheumatoid arthritis].

OBJECTIVE: The purpose of this study was to observe the association between inflammation status/autoimmune antibodies and plasma lipid in patients with rheumatoid arthritis (RA). METHODS: A total of 402 RA patients were admitted into our hospital during January 2008 to March 2009 and 225 RA patients who met the inclusion criteria were selected to perform a full lipid profile examination including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), anti-keratin antibody (AKA), anti-perinuclear factor autoantibody (APF) and complement (C) were also evaluated. Atherogenic index of plasma (AIP) was calculate by the formula Log (TG/HDL-C). RESULTS: (1) There were 12.9%, 10.2% and 14.2% patients with elevated TC, LDL-C and TC respectively, patients with reduced HDL-C accounted for 43.6%. (2) C(3) was higher in elevated TC group than normal TC group (P < 0.05). ESR and CRP were significantly higher in decreased HDL-C group than in normal HDL-C group (P < 0.05). CRP, C(3) and C(4) were significantly higher in elevated LDL-C group than in normal LDL-C group (P < 0.05). (3) Multiple stepwise regression analysis showed that C(3) was positively correlated with TC (R(2) = 0.067, P < 0.05). Both ESR and CRP were negative correlated with HDL-C (R(2) = 0.202, P < 0.05). CRP and anti-CCP were positively correlated with LDL-C (R(2) = 0.129, P < 0.05). ESR and C(4) were positively correlated with AIP (R(2) = 0.046, P < 0.05). CONCLUSION: This study showed that rheumatoid arthritis is associated with an abnormal lipid profile, especially in patients with increased inflammation markers and autoimmune antibodies. Moreover, ESR and C(4) were predictors of increased AIP in this cohort.

[Novel mutations of cardiac troponin T in Chinese patients with hypertrophic cardiomyopathy].

OBJECTIVE: To screen the cardiac troponin T (TNNT2) mutations in Chinese patients with hypertrophic cardiomyopathy (HCM) and to analyze the potential link between the genotype and the phenotype. METHODS: Clinical features of 100 probands with HCM and some family members were evaluated, 200 unrelated normal subjects served as control. The exons and flanking introns of TNNT2 were amplified with PCR and direct sequencing was used to screen TNNT2 mutations/polymorphisms. RESULTS: Two novel missense mutations were detected in 2 HCM patients: R92W and R286H. These 2 mutations were not found in 200 non-HCM controls. A five-basepair insertion/deletion polymorphism in intron 3 of TNNT2 was identified in this HCM cohort but was not related to the phenotype. CONCLUSIONS: Two missense mutations, R92W and R286H, were found in 2/100 patients with HCM, TNNT 2 mutation is relatively low in Chinese patients with HCM.

The Healthy Taiwanese Eating Approach is inversely associated with all-cause and cause-specific mortality: A prospective study on the Nutrition and Health Survey in Taiwan, 1993-1996.

BACKGROUND: Few longitudinal studies have investigated the association between foods/dietary pattern and mortality risk in the Asian population. We investigated the prospective association between foods/dietary pattern and risk of death among ethnic Chinese adults in Taiwan. METHODS: The study population included 2475 young and middle-aged adults (aged 18-65 years at baseline) who completed the questionnaires and physical examinations in the Nutrition and Health Survey in Taiwan from 1993 to 1996. A food frequency questionnaire was administered to assess food consumption habits in a face-to-face interview. With survey data linked to the Taiwanese Death Registry, Cox proportional hazard model was used to identify the foods associated with all-cause mortality(followed until 2012), which were then tallied to calculate a dietary pattern score called Taiwanese Eating Approach(TEA) score. The TEA scores were then associated with various kinds of mortality outcomes. In addition, data from 431 elders (aged≥65 yrs) with 288 death endpoints were used to conduct a sensitivity analysis. RESULTS: A total of 385(15.6%) participants died (111 cardiovascular related deaths and 122 cancer related deaths) during the 17.8-year follow-up period(41274 person-years). Twelve foods (9 inverse [vegetables/fish/milk/tea](+1) and 3 positive[fatty meats/fermented vegetables/sweet drinks](-1)) were significantly associated with all-cause mortality risk. All adults were grouped by their cumulative food score into three diet groups: poor diet(29.3% of all subjects), average diet(44.0%), and healthy diet(26.70%). The better the diet, the lower the total, cardiovascular, and other cause mortality outcomes (trend-p < .001). The hazard ratio for the healthy diet was 0.64 (95% confidence interval:0.47-0.87) for total mortality, and 0.52(0.28-0.95) for cardiovascular death, compared with the poor diet in the multivariable models. This phenomenon was also seen in older adults for all-cause, cancer, and other cause mortalities. CONCLUSION: Consuming a healthy Taiwanese Eating Approach (TEA) diet is negatively associated with all-cause, cardiovascular, and other-cause mortalities in Taiwan.

The Role of Autophagy in Cancer Radiotherapy.

BACKGROUND: Autophagy, a pathway for lysosomal-mediated cellular degradation, is a catabolic process that recycles intracellular components to maintain metabolism and survival. It is classified into three major types: macroautophagy, microautophagy, and the chaperone-mediated autophagy (CMA). Autophagy is a dynamic and multistep process that includes four stages: nucleation, elongation, autophagosome formation, and fusion. Interestingly, the influence of autophagy in cancer development is complex and paradoxical, suppressive, or promotive in different contexts. Autophagy in cancer has been demonstrated to serve as both a tumour suppressor and promoter. Radiotherapy is a powerful and common strategy for many different types of cancer and can induce autophagy, which has been shown to modulate sensitivity of cancer to radiotherapy. However, the role of autophagy in radiation treatment is controversial. Some reports showed that the upregulation of autophagy was cytoprotective for cancer cells. Others, in contrast, showed that the induction of autophagy was advantageous. Here, we reviewed recent studies and attempted to discuss the various aspects of autophagy in response to radiotherapy of cancer. Thus, we could decrease the viability of cancer cell and increase the sensibility of cancer cells to radiation, providing a new basis for the application of autophagy in clinical tumor radiotherapy.

Hyperuricemia and pulse pressure are predictive of incident heart failure in an elderly population.

OBJECTIVE: This study investigated the associations between hyperuricemia, pulse pressure (PP) and heart failure (HF) hospitalization among the elders in a community population. BACKGROUND: Hyperuricemia and PP have been related to the development of HF. Whether PP acts synergistically with hyperuricemia or mediates the causal relationship of HF, especially in the elderly, remains elucidated. METHODS: This cohort included 1665 adults aged ≥65 years from the National Nutrition and Health Survey in Taiwan Elderly were followed. HF hospitalization (ICD-9-CM:428) was defined by the National Health Insurance Dataset. A Cox proportional hazard model and a Fine and Grays model were adjusted for the conventional cardiovascular risk factors and death as a competing risk to estimate the association between hyperuricemia, PP and HF hospitalization. RESULTS: A total of 228 elders occurred HF hospitalization, and 692 died during a median of 12 years follow-up period, from 1999 to 2012. The incidence of HF was 14.2 per 1000 person-years. High PP (top quartile) and hyperuricemia (≥6.0 mg/dL [women] and 7.0 mg/dL [Men]) significantly correlated with incident HF (hazard ratio and 95% confidence intervals: 2.131;1.625-2.794 and 1.433;1.071-1.918, respectively). Compared with normal uric acid level and PP, combined hyperuricemia and high PP was additively related to incident HF (4.186:2.874-6.099). The associations remained after accounting for traditional cardiovascular risks, coronary heart disease as a time-dependent covariate, and mortality as a competing risk factor in the study population. CONCLUSION: Both hyperuricemia and high PP were associated with HF hospitalization in this elderly population. Combine hyperuricemia and high PP would further improve the risk stratification in the prediction of incident HF.

[Novel MYBPC3 mutations in Chinese patients with hypertrophic cardiomyopathy].

OBJECTIVE: To screen the MYBPC3 gene mutations in Han Chinese patients with hypertrophic cardiomyopathy (HCM). METHODS: Sixty-six patients with HCM were enrolled for the study. The exons in the functional regions of MYBPC3 were amplified with PCR and the products were sequenced. RESULTS: Four novel mutations and four common polymorphisms were identified in this patient cohort. A Lys301fs mutation in exon10 was evidenced in a H30, and when he was 47 years old, he had the chest tightness, shortness of breath with septal hypertrophy of 18.7mm; a Asp463stop mutation in exon17 was detected in a H48, he was 24 years old 24-year-old when a medical examination showed ventricular septal hypertrophy of 15.4 mm; both Gly523Arg mutation in exon18 and Tyr847His mutation in exon26 were found in a H53 with onset age 36 years old, feeling chest tightness after excise and his ventricular septal hypertrophy was 27 mm that time. MYBPC3 mutations occurred in 4.5% patients in this cohort. These mutations were not found in 100 non-HCM control patients. CONCLUSION: MYBPC3 mutation is presented in a small portion of Han Chinese patients with HCM.

Modeling the Spatial Distribution of Plateau Pika (Ochotona curzoniae) in the Qinghai Lake Basin, China.

The plateau pika (Ochotona curzoniae) is a keystone species in the alpine rangeland ecosystem of the Qinghai-Tibetan Plateau. Most previous studies of habitat selection by plateau pika have been conducted at a local microhabitat scale; however, little is known about the relationship between the distribution of plateau pika and macrohabitat factors at broad spatial scales. Using a presence-only ecological niche model (maximum entropy, Maxent), we predicted the distribution of plateau pika in the Qinghai Lake basin based on a set of environmental and anthropogenic variables at 1-km spatial resolution, and identified key macrohabitat factors that contribute to the predictive performance. Our results showed suitable area for plateau pika in the Qinghai Lake basin being approximately 3982 km2, which is 15.8% of the land area in the whole watershed. The distance to road emerged as the most important predictor of the distribution patterns of plateau pika, while the soil type was of ancillary importance. Mean air temperature of wettest quarter, distance to resident site and altitude also produced high gains in defining plateau pika's distribution. A higher predictive accuracy was achieved by the model that combined environmental and anthropogenic variables. With the constraint of human factors, the presence probability of plateau pika in about 1661 km2 will increase. These findings demonstrate the impact of human activities on the distribution of plateau pika, and the importance of vegetation reservation for plateau pika control.

The Role of MMP-9 in Regulating Degradation of the Splenic Microvascular Basement Membrane Induced by High Altitude Hypoxia / Rol de la MMP-9 en la Regulación de la Degradación de la Membrana Basal Microvascular Esplénica Inducida por Hipoxia de Altura

SUMMARY: To investigate changes of MMP-9 in the rat spleen and hypoxia-induced microvascular basement membrane under high altitude hypoxia. Thirty male specific pathogen-free Sprague Dawley rats were randomly divided into control and hypoxia groups, with 15 rats in each group. The rats in the control group were placed in Dingxi City, Gansu Province (2080 m above sea level) for 30 days. Rats in the hypoxia group were raised in a hypoxic environment in Maduo County, Qinghai Province (4300 m above sea level), for 30 days to establish a hypoxic rat model. Routine blood tests, MMP-9 mRNA, MMP-9 protein, and the spleen microvascular basement membrane were detected. (1) Compared with the control group, the red blood cell count, hemoglobin, and hematocrit levels of the rats in the hypoxia group were all increased; thus, a hypoxia model was successfully established. (2) Compared with the control group, the expression of MMP-9 mRNA and protein was significantly higher in the spleen of rats in the hypoxic group, and the difference was statistically significant (P <0.05). (3) Compared with the control group, the blood vessel basement membrane in the spleen of the hypoxia group was degraded. Under natural low air pressure and high altitude conditions, the expression of MMP-9 in rat spleen tissue increases and participates in the degradation of the microvascular basement membrane.

El objetivo de este trabajo fue investigar los cambios de la MMP-9 en el bazo de la rata y la membrana basal microvascular inducida bajo hipoxia a gran altura. Treinta ratas macho Sprague Dawley, libres de patógenos específicos, se dividieron aleatoriamente en dos grupos de 15 ratas cada uno, un grupo control y un grupo hipoxia. Durante 30 días las ratas del grupo control estuvieron en la ciudad de Dingxi, provincia de Gansu (2080 m sobre el nivel del mar). Las ratas del grupo de hipoxia se criaron en un entorno hipóxico en el condado de Maduo, provincia de Qinghai (4300 m sobre el nivel del mar), durante 30 días para establecer un modelo de rata hipóxica. Se realizaron análisis de sangre de rutina, ARNm de MMP-9, proteína MMP-9 y de la membrana basal microvascular del bazo. En comparación con el grupo control, el recuento de glóbulos rojos, la hemoglobina y los niveles de hematocrito de las ratas del grupo de hipoxia aumentaron; por lo tanto, se estableció con éxito un modelo de hipoxia. En comparación con el grupo control, la expresión de ARNm y proteína de MMP-9 fue significativamente mayor en el bazo de las ratas del grupo hipóxico, siendo la diferencia estadísticamente significativa (P <0,05). En comparación con el grupo control, la membrana basal de los vasos sanguíneos estaba degradada en el bazo del grupo hipoxia. En condiciones naturales de baja presión atmosférica y gran altitud, la expresión de MMP-9 en el tejido del bazo de la rata aumenta y participa en la degradación de la membrana basal microvascular.

[Seasonal divergence in the responses of vegetation growth to PDO in Tibetan Plateau, China]. / 青藏高原植被生长对PDO响应的季节分异.

Regional-scale normalized difference vegetation index (NDVI) derived from satellite remote sensing observations and gridded climate data were used to study the seasonal responses and underlying mechanisms of vegetation growth over Tibetan Plateau to Pacific Decadal Oscillation (PDO) at period of 1982-2015, by performing Spearman correlation analysis and enhanced multivariate regression model: structural equation model (SEM). The results showed that there was significant negative correlation between PDO index and mean growing-season (April-October) NDVI over Tibetan Plateau; however, marked seasonal divergence in the relationship between PDO and vegetation growth existed among different seasons. It characterized with stronger negative correlation between PDO and NDVI in autumn than in summer, and winter PDO had significant effect on consequent summer vegetation growth. Additionally, it showed great divergence in control processes of PDO on vegetation growth among different seasons, with significant control of PDO on both temperature and precipitation in summer, and significant control of PDO on temperature only in autumn.

[A survey of Brugada-type electrocardiogram recorded from high right precordial spaces in healthy Chinese].

OBJECTIVE: To investigate the prevalence and the significance of the Brugada-type electrocardiogram (ECG) recorded from higher intercostal space in healthy Chinese. METHODS: The population of the present study consisted of 1005 subjects receiving a health examination. All subjects underwent history inquiry, physical examination and chest X-ray survey. ECGs were taken from the 4th and the 2nd intercostal spaces and examined for Brugada-type ECG according to the diagnostic criteria recommended by European Society of Cardiology. RESULTS: Four patients with cardiovascular disorders were excluded and a total of 1001 healthy subjects [age 17 - 75 years, mean (28.3 +/- 14.8) years, 877 males and 124 females] were included in the study. Five males of the 1001 subjects (0.50%) had Brugada-type 2 pattern on routine 12-lead ECGs. Forty-seven males of all the subjects (4.70%) had Brugada-type ECGs recorded from the 2nd intercostal space and Brugada-type 2 and type 3 patterns were found in 40 and 7 respectively. All these males had no unaccountable syncope, presyncope or a family history of sudden death. CONCLUSIONS: It should be careful to diagnose of Brugada syndrome according to Brugada-type 2 or type 3 ECGs recorded from either the 4th or higher intercostal spaces when typical symptoms are absent.

[The mechanistic rote of KCNH2 gene L413P and L559H mutations in long QT syndrome].

OBJECTIVE: To investigate the molecular pathogenesis for two novel mutations L413P and L559H of KCNH2 found in Chinese patients with long QT syndrome. METHODS: L413P and L559H mutant constructs were generated by site-directed mutagenesis using human wild-type (WT) pcDNA3-HERG cDNA as a template. WT and mutant constructs were transiently transfected into human embryonic kidney 293 cells using lipofectamine method. After transfection, the recording of HERG current was performed using patch clamp technique. The expression and cellular localization of HERG protein were studied with Western blot and immunofluorescence methods. RESULTS: Electrophysiological recordings showed that L413P and L559H mutations did not express HERG current. Western blot analysis revealed that only 135 000 immature HERG protein was expressed in L413P and L559H-transfected cells, whereas both mature and immature forms of HERG protein were observed in WT-transfected cells. Immunofluorescence study showed that L413P and L559H mutant proteins were predominantly localized around the nucleus, suggesting that the mutant channels are retained in the endoplasmic reticulum. When L413P or L559H was co-transfected with equal amount of WT plasmids, both 135 000 and 155 000 forms of HERG protein were observed, and the HERG current was not significantly changed as compared with that of WT transfection alone. Low temperature and E-4031could not rescue these two mutant channels. CONCLUSIONS: The L413P and L559H mutations resulted in protein trafficking defects with failure of mutant proteins to reach the plasma membrane. However, both biochemical and electrophysiological results showed that the mutations did not have a dominant-negative effect on WT, indicating that the mechanism of the L413P and L559H mutations might be haploinsufficiency.

[Application of transgenic animal in hypertrophic cardiomyopathy].

Hypertrophic cardiomyopathy is an autosomal-dominant disease. Disease-causing mutations have been found in genes encoding structural components of the thick and thin filament systems of cardiac myocyte; it has therefore been named as a disease of sarcomere. Many approaches have been used to characterize the pathogenesis of the disease. Transgenic animal models have been created to gain further insight into the pathogenesis of this disease. Most of these models has been made in mice; however, recently a transgenic rabbit model has been created. In addition, there are several natural-occurring forms of HCM in animals. The discovery of responsible genes and the elucidation of the molecular mechanisms of pathogenesis through the use of animal models promise improved and early diagnosis and the potential for mechanism-based therapeutics.

[Novel mutations of potassium channel KCNQ1 S145L and KCNH2 Y475C genes in Chinese pedigrees of long QT syndrome].

OBJECTIVE: Hereditary long QT syndrome (LQTS) is a cardiac disorder characterized by prolongation of QT interval on electrocardiograms (ECGs) and syncope and sudden death caused by a specific multi-polymorphic ventricular tachyarrhythmia known as torsade de pointes. LQTS is caused by mutations in cardiac sodium channel gene SCN5A; potassium channel subunit genes KCNQ1, KCNH2, KCNE1, KCNE2, KCNJ2; calcium channel gene Cav2.1. and ankyrin-B gene ANK2. METHODS: We characterized 77 Chinese LQTS patients with clinical manifestations and mutations in the main LQTS genes, KCNQ1 and KCNH2 using PCR and sequence analysis. RESULTS: The spectrum of ST-T-wave patterns of 24 (31.2%) probands were considered as LQT1, 42 (54.5%) as LQT2 and 3 (3.9%) as LQT3. The remaining 8 (10.3%) could not be characterized. The average age for this population of LQTS patients was (27.6 +/- 16.4) years and the average QTc (561 +/- 70) ms, and the age of the first syncopal attack was (17.6 +/- 14.7) years. The triggering factors for cardiac events happening in these mutation carriers included physical exercise, emotional excitement and auditory irritation. We identified 4 KCNQ1 mutations and 7 KCNH2 mutations. Six of them were first identified with some data already shown. In this paper we showed the data of 6 other mutations. CONCLUSIONS: LQT2 is the most common type of LQTS in Chinese; 2 mutations of KCNQ1 and KCNH2 were first identified in this report; there are some differences between Chinese and North American or European LQTS patients in clinical characters and ECG.