Mental health problems and social supports in the COVID-19 healthcare workers: a Chinese explanatory study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has spread rapidly in China and other overseas areas, which has aroused widespread concern. The sharp increase in the number of patients has led to great psychological pressure on health care workers. The purpose of this study was to understand their mental health status and needs, so as to provide a scientific basis for alleviating the psychological pressure of health care workers. METHODS: Using a cross-sectional study design, 540 health care workers were randomly selected from two designated tuberculosis medical institutions in Anhui Province. The basic situation, perceived social support, depression level, loneliness and COVID-19 related knowledge were collected and analyzed by questionnaire. RESULTS: A total of 511 valid questionnaires were finally retrieved. There were 139 people in epidemic prevention and control positions (27.20%). Depression level: People in isolation ward, fever clinic and pre-check triage were at the level of mild to moderate depression. Female was higher than male; nurse was higher than doctor; middle and junior job titles were higher than senior titles; junior college degree or below were higher than bachelor's degree, master's degree and above; isolation ward, fever clinic and pre-check triage were significantly higher than those of non-prevention and control positions (p < 0.05). Loneliness scores: Doctors were higher than that of medical technicians, and isolation ward, fever clinic and pre-check triage were higher than those of other medical departments (p < 0.05). Social support: Doctors were lower than that of medical technicians, and isolation ward, fever clinic and pre-check triage were significantly lower than those of other departments (p < 0.05). The score of social support was negatively correlated with depression and loneliness (p < 0.001), while depression was positively correlated with loneliness (p < 0.001). Health care workers most want to receive one-to-one psychological counseling (29.75%), and provide crisis management (24.07%). The awareness rate of health care workers on COVID-19's knowledge was relatively high. CONCLUSIONS: The psychological problems of health care workers, especially women, nurses with low educational background, low professional title, and staff in the epidemic prevention and control positions are relatively serious.

Short-term effect of ambient temperature change on the risk of tuberculosis admissions: Assessments of two exposure metrics.

BACKGROUND: Although the effects of seasonal variations and ambient temperature on the incidence of tuberculosis (TB) have been well documented, it is still unknown whether ambient temperature change is an independent risk factor for TB. The aim of this study was to assess the association between ambient temperature change and the risk of TB admissions. METHOD: A distributed lag non-linear model (DLNM) combined with Poisson generalized linear regression model was performed to assess the association between ambient temperature change and the risk of TB admissions from 2014 to 2018 in Hefei, China. Two temperature change metrics including temperature change between neighboring days (TCN) and diurnal temperature range (DTR) were used to assess the effects of temperature change exposure. Subgroup analyses were performed by gender, age and season. Besides, the attributable risk was calculated to evaluated the public health significance. RESULTS: The overall exposure-response curves suggested that there were statistically significant associations between two temperature change metrics and the risk of TB admissions. The maximum lag-specific relative risk (RR) of TB admissions was 1.088 (95%CI: 1.012-1.171, lag 4 day) for exposing to large temperature drop (TCN= -4 °C) in winter. Besides, the overall cumulative risk of TB admissions increased continuously and peaked at a lag of 7 days (RR=1.350, 95%CI: 1.120-1.628). Subgroup analysis suggested that exposure to large temperature drop had an adverse effect on TB admissions among males, females and adults. Similarly, large level of DTR exposure (DTR=15 °C) in spring also increased the risk of TB admissions on lag 0 day (RR=1.039, 95%CI: 1.016-1.063), and the cumulative RRs peaked at a lag of 1 days (RR=1.029, 95%CI: 1.012-1.047). We also found that females and elderly people were more vulnerable to the large level of DTR exposure. Additionally, the assessment of attributable risk suggested that taking target measures for the upcoming large temperature drop (b-AF = 4.17%, 95% eCI: 1.24%, 7.22%, b-AN = 1195) may achieve great public health benefits for TB prevention. CONCLUSION: This study suggests that ambient temperature change is associated with the risk of TB admissions. Besides, TCN may be a better predictor for the TB prevention and public health.

Association between short-term exposure to ambient air pollutants and the risk of tuberculosis outpatient visits: A time-series study in Hefei, China.

BACKGROUND: The current evidence has presented mixed results between air pollutants exposure and the progression of tuberculosis (TB). The purpose of this study was to explore the association between short-term exposure to air pollutants and the risk of TB outpatient visits in Hefei, China. METHODS: Time-series analysis was used to assess the effect of short-term exposure to ambient air pollutants on the risk of TB outpatient visits. A Poisson generalized linear regression model combined with a distributed lag non-linear model (DLNM) was applied to explore the association. The effects of different gender (male, female), age (≤65 years old, >65 years old) and season (cold season, warm season) on the risk of TB were investigated by stratified analysis. Sensitivity analyses were conducted to test the robustness of our findings. RESULTS: A total of 22,749 active TB cases were identified from November 1, 2013 to December 31, 2018 in Hefei. The overall exposure-response curve showed that the concentration of particulate matter with aerodynamic diameter less than 2.5 µm (PM2.5) and nitrogen dioxide (NO2) exposure were positively correlated with the risk of TB outpatient visits, while ozone (O3) and sulfur dioxide (SO2) exposure were negatively correlated with the risk of TB outpatient visits. The maximum lag-specific and cumulative relative risk (RR) of TB outpatient visits were 1.057 [95%CI: 1.002-1.115, lag 3 day] and 1.559 (95%CI: 1.057-2.300, lag 13 days) for each 10 µg/m³ increase in PM2.5; 1.026 (95% CI: 1.008-1.044, lag 0 day) and 1.559 (95%CI: 1.057-2.300, lag 07 days) for each 10 µg/m³ increase in NO2; 0.866 (95% CI: 0.801-0.935, lag 5 day) and 0.852 (95%CI: 1.01-1.11, lag 0-14 days) for each 10 µg/m³ increase in SO2 in the single-pollutant model. There was only a negative association between O3 exposure and the cumulative risk of TB outpatient visits (RR = 0.960, 95%CI: 0.936-0.984, lag 07 days). Stratified analyses showed that the effects of SO2 and O3 exposure were different between warm and cold seasons. The effect of NO2 exposure remained statistically significant in male, younger, and cold season subgroups. Besides, elderly people are more susceptible to PM2.5 exposure. CONCLUSION: This study suggests that exposure to PM2.5, NO2, SO2, and O3 are associated with the risk of TB outpatient visits. Seasonal variation may have a greater impact on the risk of TB outpatient visits compared with gender and age.

Prevalence of and Factors Influencing Anti-Tuberculosis Treatment Non-Adherence Among Patients with Pulmonary Tuberculosis: A Cross-Sectional Study in Anhui Province, Eastern China.

BACKGROUND To assess the non-adherence rate among pulmonary tuberculosis (TB) patients in Anhui Province, eastern China and to explore the influential factors, so as to identify targets for intervention. MATERIAL AND METHODS A total of 339 TB patients were recruited from TB dispensaries in 8 counties of Anhui Province, eastern China using a stratified sampling method. All study subjects were surveyed using a structured questionnaire. Differences between groups involving categorical data were analyzed using the chi-square test. RESULTS Overall, of the 339 patients, 33.63% missed medication. Divorced and widowed patients were more likely to miss medication compared with those who were married or unmarried (P<0.01). Regarding the knowledge related to topics such as transmission route, preventive measures, and suspicious symptoms, the awareness rate in the group with good medication compliance was higher than in the group with poor compliance (P<0.05). We found that compliance was not significantly associated with seeking medical treatment in professional institutions, the national free TB treatment policy, or discrimination (P>0.05). The rate of non-compliance under supervision (26.10%) was lower than that without supervision (64.18%) (P<0.001). CONCLUSIONS The anti-TB treatment non-adherence rate in TB patients is relatively high in Anhui Province, eastern China, and is associated with marital status, annual income, TB knowledge, and medical staff visits.

Effect of Short Message Service on Management of Pulmonary Tuberculosis Patients in Anhui Province, China: A Prospective, Randomized, Controlled Study.

BACKGROUND To explore the significance of short message service (SMS) on the management of pulmonary tuberculosis (TB) patients in reinforcing the treatment adherence and health awareness, and provide scientific evidences for popularizing this model and formulating related polices and measures. MATERIAL AND METHODS Six counties (districts) were selected by stratified cluster sampling method, and randomly divided into control group and intervention group. Pulmonary TB patients eligible to the study criteria were included in the study. SMS management and regular education of core knowledge about pulmonary TB were carried out in SMS group patients. The conventional directly observed therapy (DOT) was carried out in control group. Data was collected by questionnaire method. RESULTS A total of 350 patients were included in the study, including 160 cases in the SMS group and 190 cases in the control group. There were 270 males (77.1%) and 80 females (22.9%). The treatment completion rate in SMS group (96.25%) was significantly higher than that in the control group (86.84%) (χ²=9.52, P=0.002). Both the interrupted treatment rate and the missed dose rate in the SMS group were significantly lower than those in the control group (χ²=10.41, P=0.001; χ²=28.54, P<0.001). After a period of treatment, the reexamination rate of SMS group patients was significantly higher than that in control group (except the reexamination rate after 5 months treatment). CONCLUSIONS The management of pulmonary TB patients by SMS can effectively reinforce the completed treatment rate of pulmonary TB patients and reduce their missed dose rate and interrupted treatment rate, and further enhance their reexamination awareness. Therefore, SMS on the management of patients may be a new promising therapeutic strategy for pulmonary TB.

Kv1.3 potassium channel mediates macrophage migration in atherosclerosis by regulating ERK activity.

Ion channels expressed in macrophages have been tightly related to atherosclerosis by coupling cellular function. How the voltage-gated potassium channels (Kv) affect macrophage migration remain unknown. The aim of our study is to investigate whether Kv1.3-ERK signaling pathway plays an important role in the process. We explored the expression of Kv1.3 in coronary atherosclerotic heart disease and found Kv1.3 channel was increased in acute coronary syndrome patients. Treatment of RAW264.7 cells with Kv1.3 small interfering RNA, suppressed cell migration. The expression of phosphorylated ERK1/2 also decreased after knockdown of Kv1.3. On the other hand, overexpression of Kv1.3 channel promoted cell migration and ERK1/2 phosphorylation. U-0126, the mitogen-activated protein kinase inhibitors, could reverse macrophage migration induced by Kv1.3 channel overexpression. Downregulation of Kv1.3 channel by siRNA could not further inhibit cell migration when cells were treated with U-0126. It means that ERK is downstream signal of Kv1.3 channel. We concluded that Kv1.3 may stimulate macrophage migration through the activation of ERK.

Associations of exposures to air pollution and greenness with mortality in a newly treated tuberculosis cohort.

Some previous studies had linked air pollutants and greenness to the risk of death from tuberculosis (TB). Only a few studies had examined the effect of particulate matter (PM2.5) on the mortality of TB, and few studies had assessed the impact and interaction of multiple air pollutants and greenness on the mortality of newly treated TB patients. The study included 29,519 newly treated TB patients from three cities in Anhui province. We collected meteorological data and five pollutants data from The National Meteorological Science Center and air quality monitoring stations. Greenness data were generated by remote sensing inversion of medium-resolution satellite images. We geocoded each patient based on the residential address to calculate the average exposure to air pollutants and the average greenness exposure for each patient during treatment. The Cox proportional risk regression model was used to evaluate the effects of air pollutants and greenness on mortality in newly treated tuberculosis patients. Our results found that the higher the concentration of air pollutants in the living environment of newly treated TB patients, the greater the risk of death: HR 1.135 (95% CI: 1.123-1.147) and HR 1.333 (95% CI: 1.296-1.370) per 10 µg/m3 of PM2.5 and SO2, respectively. Greenness reduced the mortality among newly treated TB patients: HR for NDVI exposure 0.936 (95% CI: 0.925-0.947), HR for NDVI_250m exposure 0.927 (95% CI: 0.916-0.938), and HR for NDVI_500m exposure 0.919 (95% CI: 0.908-0.931). Stratifying the cohort by median greenness exposure, HRs for air pollutants were lower in the high greenness exposure group. Mortality in newly treated TB patients is influenced by air pollutants and greenness. Higher green exposure can mitigate the effects of air pollution. Improving air quality may help reduce mortality among newly treated TB patients.

Prevalence and clinical implications of polypharmacy and potentially inappropriate medication in elderly patients with heart failure: results of six months' follow-up.

OBJECTIVES: To investigate the prevalence of polypharmacy and potentially inappropriate medication (PIM) in elderly patients with heart failure (HF) and their impact on readmission and mortality. METHODS: We conducted a study of 274 participants aged 60 years or older with HF. The prevalence of polypharmacy (defined as the use of five or more medications) was calculated, and the 2019 American Geriatrics Society Beers criteria were applied to access PIMs. Medications and PIMs were characterized at admission and discharge, and changes in prescriptions during hospitalization were compared. The impact of polypharmacy and PIM on readmission and mortality were investigated. RESULTS: The median age of this study population was 68 years old. The median number of prescribed drugs was 7 at admission and 10 at discharge. At discharge, 99.27% of all patients were taking five or more drugs. The incidence of composite endpoint and cardiovascular readmission increased with the number of polypharmacy within 6 months. The use of guideline-directed medical therapy reduced the incidence of composite endpoint events and cardiovascular readmission, while the use of non-cardiovascular medications increased the composite endpoint events. The frequency of PIMs was 93.79% at discharge. The incidence of composite endpoint events increased with the number of PIMs. "PIMs in older adults with caution" increased cardiovascular readmission and "PIMs based on kidney function" increased cardiovascular mortality. Several comorbidities were associated with cardiovascular mortality or non-cardiovascular readmission. CONCLUSIONS: Polypharmacy and PIM were highly prevalent in elderly patients with HF, and their use was associated with an increased risk of composite endpoint events, readmission and mortality. Non-cardiovascular medications, "PIMs in older adults with caution", "PIMs based on kidney function" and several comorbidities were important factors associated with hospital readmission and mortality. Our findings highlight the importance of medication optimization in the management of HF in elderly patients.

Effect of gaseous pollutant and greenness exposure on mortality during treatment of newly treated tuberculosis patients: a provincial population-based cohort study.

BACKGROUND: Previous studies addressing the impact of environmental factors on TB prognosis are scarce, with only some studies examining the effect of particulate pollutants on TB mortality. Moreover, few studies have evaluated the effects of multiple gaseous pollutants and greenness exposures on newly treated TB patients on a large population scale. METHODS: Through the Centers for Disease Control and Prevention, data were collected from January 1, 2015 to December 31, 2020 for newly treated TB patients in Anhui Province, China. Data on gaseous pollutants sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone were collected through the National Earth System Science Data Center of China. Normalized vegetation index data were obtained through NASA. The Cox proportional risk model was also applied to calculate the hazard ratios of SO2, NO2, CO, O3, and NDVI with 95% confidence intervals for mortality among newly treated TB patients. RESULTS: Multifactorial Cox regression analysis showed that for every 0.10 µg/m3 increase in SO2, the risk of death among newly treated TB patients increased by 13.2% (HR = 1.132, 95% CI: 1.045-1.1.225), for every 10 µg/m3 increase in NO2, the risk of death among newly treated TB patients increased by 11.4%, and for each 0.1 mg/m3 increase in CO, the risk of death among newly treated TB patients increased by 5.8%. For each 0.1 increase in NDVI 250m-buffer and 500m-buffer, the risk of death among newly treated TB patients decreased by 8.5% and 6.4%, respectively. The effect of gaseous pollutants on mortality decreased progressively with elevated greenness exposure when greenness exposure was grouped from low to high. CONCLUSION: Gaseous pollutants are a risk factor during the treatment of newly treated TB patients and greenness exposure is a protective factor. Higher greenness exposure reduces the risk of death due to exposure to gaseous pollutants.

Nutritional status in patients with active pulmonary tuberculosis and new nutritional risk screening model for active tuberculosis: a national, multicenter, cross-sectional study in China.

Background: Tuberculosis (TB) remains a significant challenge for public health and is closely associated with malnutrition; however, few studies have attempted to screen malnutrition among TB patients. The study aimed to evaluate the nutrition status and build a new nutritional screening model for active TB. Methods: A retrospective, multicenter, large cross-sectional study was conducted in China from 1 January 2020 to 31 December 2021. All included patients diagnosed with active pulmonary TB (PTB) were evaluated both by Nutrition Risk Screening 2002 (NRS 2002) and Global Leadership Initiative on Malnutrition (GLIM) criteria. Univariate and multivariate analyses were conducted to screen the risk factors associated with malnutrition, and a new screening risk model, mainly for TB patients, was constructed. Results: A total of 14,941 cases meeting the inclusion criteria were entered into the final analysis. The malnutrition risk rate among PTB patients in China was 55.86% and 42.70%, according to the NRS 2002 and GLIM, respectively. The inconsistency rate between the two methods was 24.77%. A total of 11 clinical factors, including elderly, low body mass index (BMI), decreased lymphocyte cells, taking immunosuppressive agents, co-pleural TB, diabetes mellitus (DM), human immunodeficiency virus (HIV), severe pneumonia, decreased food intake within a week, weight loss and dialysis were identified as independent risk factors of malnutrition based on multivariate analyses. A new nutritional risk screening model was constructed for TB patients with a diagnostic sensitivity of 97.6% and specificity of 93.1%. Conclusions: Active TB patients have severe malnutrition status according to screening by the NRS 2002 and GLIM criteria. The new screening model is recommended for PTB patients as it is more closely tailored to the characteristics of TB.

Short-term effect of ambient air pollutant change on the risk of tuberculosis outpatient visits: a time-series study in Fuyang, China.

There is growing evidence that air pollution plays a role in TB, and most studies have been conducted in the core countries with inconsistent results. Few studies have comprehensively included the six common air pollutants, so they cannot consider whether various pollutants interact with each other. Our objectives were to investigate the association between short-term exposure to six common air pollutants and the risk of tuberculosis outpatient visits in Fuyang, China, 2015-2020. We combined the two models to explore the effects of exposure to six air pollutants on the risk of tuberculosis outpatient visits, including the Poisson generalized linear regression model and distributed lag non-linear model (DLNM). We performed stratified analyses for the season, type of cases, gender, and age. We used the lag-specific relative risks and cumulative relative risk obtained by increasing pollutant concentration by per 10 units to evaluate the connection between six air pollutants and TB; PM2.5 (RR = 1.0018, 95% CI: 1.0004-1.0032, delay of 12 days) and SO2 (RR = 1.0169, 95% CI: 1.0007-1.0333, lag 0-16 days) were 0.9549 (95% CI: 0.9389-0.9712, lag 0 day) and 0.8212 (95% CI: 0.7351-0.9173, 0-20-day lag). Stratified analyses showed that seasonal differences had a greater impact on TB, males were more likely to develop TB than females, older people were more likely to develop TB than younger people, and air pollution had a great impact on new cases. Exposure to O3, CO, PM10, PM2.5, and NO2 increases the risk of TB outpatient visits, except SO2 which reduces the risk. The incidence of TB has seasonal fluctuations. It is necessary for the government to establish a sound environmental monitoring and early warning system to strengthen the monitoring and emission management of pollutants in the atmosphere. Management, prevention, and treatment measures should be developed for high-risk groups (males and older people), reducing the risk of TB by reducing their specific behaviors and changing their lifestyle. We need to pay more attention to the impact of seasonal effects on TB to protect TB patients and avoid a shortage of medical resources, and it is necessary for the government to develop some seasonal preventive measures in the future.

Contributions of ambient temperature and relative humidity to the risk of tuberculosis admissions: A multicity study in Central China.

BACKGROUND: As a communicable disease and major public health issue, many studies have quantified the associations between tuberculosis (TB) and meteorological factors with inconsistent results. The purpose of this multicenter study was to characterize the associations between ambient temperature, humidity and the risk of TB hospitalizations and to investigate potential heterogeneity. METHOD: Data on daily hospitalizations for TB, meteorological factors and ambient air pollutants for 16 cities in Anhui Province were collected from 2015 to 2020. A distributed lag nonlinear model (DLNM) was performed to obtain the estimates of meteorological-TB relationships by cities. Then, we used the multivariate meta-regression model to pool the city-specific estimates with air pollution, demographic indicators, medical resource and latitude as potential modifiers to explore the sources of heterogeneity. Finally, we divided the whole province into three regions to validate the meteorological-TB relationships by regions. RESULTS: The overall pooled temperature-TB association presented an approximate S-shaped curve, with relative risk (RR) peaking at 5 °C (RR = 1.536, 95% CI: 1.303-1.811) compared to the reference temperature (27 °C). Lag-response curve suggested that low temperature exposure increased the risk of TB hospitalizations at lag 0 and 1 day (lag0 day: RR = 1.136, 95% CI: 1.048-1.231, lag1 day: RR = 1.052, 95% CI: 1.023-1.082). However, the overall exposure-response curve between relative humidity and TB showed almost horizontal line with reference relative humidity to 78%. The residual heterogeneity ranged from 27.1% to 36.9%, with air pollution, latitude and medical resource explained the largest proportion. CONCLUSION: We found that low temperature exposure is associated with an acute increased risk of TB hospitalizations in Anhui Province. The association between temperature and TB admission varies depending on air pollution, latitude, and medical resources. Since the effect of short-term exposure to humidity is not significant, further studies are supposed to focus on the long-term effect of humidity.

Short-term effect of sulfur dioxide (SO2) change on the risk of tuberculosis outpatient visits in 16 cities of Anhui Province, China: the first multi-city study to explore differences in occupational patients.

A growing number of biological studies suggest that exogenous sulfur dioxide (SO2) at a certain concentration may promote human resistance to Mycobacterium tuberculosis. However, the results of most relevant studies are inconsistent, and few studies have explored the relationship between SO2 exposure and tuberculosis risk at provincial level. In addition, occupational exposure has long been considered to have a certain impact on the human body, so for the first time, we discussed the differences between different occupations in the study on the relationship between air pollutant exposure and tuberculosis risk, and evaluated the impact of occupational exposure. This study aimed to explore the association between short-term SO2 exposure and the risk of outpatient visits to tuberculosis in Anhui province and 16 prefecture-level cities from 2015 to 2020. We used several models for multi-stage analysis, including distributed lag nonlinear model (DLNM), Poisson generalized linear regression model, and random-effects model. The association was assessed using the 28-day cumulative lag effect RR and 95%CI for each 10-unit increase in SO2 concentration. We divided all patients into the following six occupations: Worker, Farmer, Retired people, Children and Students, Cadre and Office clerk, and Service staff (catering, business, etc.). Sex, age, and season were analyzed by subgroup. Finally, the robustness of the multi-pollutant model was tested. At provincial level, the overall effect value of SO2 was RR=0.8191 (95%CI: 07702~0.8712); after grouping all patients by occupation, the association found only among Farmers (RR = 0.7150, 95%CI: 0.6699-0.7632, lag 0-28 days) and Workers (RR = 0.8566, 95%CI: 0.7930-0.9930, lag 0-4 days) was still statistically significant. Estimates for individual cities and using random-effects models to estimate average associations showed that SO2 exposure was associated with a reduced risk of outpatient TB visits in 14 municipalities, which remained significant when aggregated (RR = 0.9030, 95%CI: 0.8730-0.9340). Analysis of patients grouped by occupation in each municipality showed that statistical significance was again observed only in the Farmer (RR = 0.8880, 95%CI: 0.8610-0.9160) and Worker (RR = 0.8250, 95%CI: 0.7290-0.9340) groups. Stratified analysis of age, sex, and season showed that the effect of SO2 exposure was greater for middle-aged people (18-64 years old) and males, and less for seasonal changes. In summary, we found that exposure to SO2 reduces the risk of outpatient visits to tuberculosis, with farmers and workers more susceptible to SO2. Gender and age had a greater impact on the risk of TB outpatient visits than seasonal variations.

Factors influencing completion of treatment among pulmonary tuberculosis patients.

Objective: This study aimed to understand the influencing factors of treatment completion among pulmonary tuberculosis (PTB) patients in Anhui province, eastern People's Republic of China, in order to provide scientific evidence for improving the follow-up rate and treatment completion rate. Methods: A total of 262 PTB patients in six counties (districts) of Anhui province were investigated by questionnaire, and data about treatment interruption were collected. Results: The main causes of treatment interruption were forgetting to take medicine (24.5%), drug side effects (23.3%), and symptomatic improvement (19.5%). The education background, patient type, cause of interruption, and tracking method were factors influencing completion of treatment (all P<0.05). The education level was positively associated with the treatment completion rate. New smear-positive patients had a significantly higher completion rate than others. The patients interrupted by drug side effects had the highest risk of interruption. In terms of the tracking method, the completion rate of patients tracked by the rural medical staff was significantly lower. Conclusions: The management of PTB patients by medication supervision should be strengthened, especially for those with low education level and who had drug side effects, in order to improve their treatment completion rate.

A proton-activated, outwardly rectifying chloride channel in human umbilical vein endothelial cells.

Extracellular acidic pH-activated chloride channel I(Cl, acid), has been characterized in HEK 293 cells and mammalian cardiac myocytes. This study was designed to characterize I(Cl,acid) in human umbilical vein endothelial cells(HUVECs). The activation and deactivation of the current rapidly and repeatedly follows the change of the extracellular solution at pH 4.3, with the threshold pH 5.3. In addition, at very positive potentials, the current displays a time-dependent facilitation. pH-response relationship for I(Cl,acid) revealed that EC(50) is pH 4.764 with a threshold pH value of pH 5.3 and nH of 14.545. The current can be blocked by the Cl(-) channel inhibitor DIDS (100 microM). In summary, for the first time we report the presence of proton-activated, outwardly rectifying chloride channel in HUVECs. Because an acidic environment can develop in local myocardium under pathological conditions such as myocardial ischemia, I(Cl,acid) would play a role in regulation of EC function under these pathological conditions.

RETRACTED: Assessment of manidipine on left ventricular function in Chinese hypertensive patients using a tissue Doppler imaging (TDI) Tei index.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.biomag.2010.10.001 The duplicate article has therefore been withdrawn.