Association of sleep behavior with depression: a cross-sectional study in northwestern China.

Background: This study aimed to examine the association between sleep duration, sleep problems, and depression in Northwest China. Method: Depression was diagnosed at the hospital and self-reported by the participants in the baseline survey. Sleep duration and problems, including difficulty initiating and maintaining sleep, early morning awakening, daytime dysfunction, use of sleeping pills or drugs, and any sleep problems, were obtained by a self-reported questionnaire. Logistic regression was used to estimate odds ratios (ORs) with corresponding 95% confidence intervals (CIs) for exploring the association between sleep duration, sleep problems, and depression, adjusting for demographic and socioeconomic characteristics and health behaviors. The association between depression and sleep duration was also evaluated continuously with restricted cubic spline curves based on logistic models. Results: 36,515 adults from Regional Ethnic Cohort Study in Northwest China were included. About 24.04% of participants reported short sleep duration (<7 h), and 15.64% reported long sleep duration (≥9 h). Compared with standard sleep duration (7-9 h), short sleep duration was associated with a higher risk of depression (OR: 1.69, 95%CI: 1.26-2.27, p = 0.001). Self-reported sleep problems were also related to four times depression risk increased (OR: 4.02, 95%CI: 3.03-5.35, p < 0.001) compared with no sleep problems. In addition, a nonlinear relationship was found between sleep duration and depression after adjusting covariates (p = 0.043). Conclusion: Sleep duration and sleep problems are associated with depression. Enough sleep time and healthy sleep habits in life course might be a practical health promotion approach to reduce depression risk in Northwest Chinese adults. A further study from cohort study is needed to verify the temporal association.

Age at smoking initiation and smoking cessation influence the incidence of stroke in China: a 10-year follow-up study.

Our study aimed to explore the correlation between age at smoking initiation and smoking cessation for the risk for stroke in China. We investigated 50,174 participants from one of the urban areas of China Kadoorie Biobank (CKB) Study. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for association between smoking and incidence of stroke were estimated using Cox regression model. During a median of 10.7 years of follow-up, 4370 total stroke cases were documented. Among men, comparing current smokers to never smokers, the HR of total stroke for current smokers was 1.279 (95% CI, 1.134-1.443) for total stroke. The HRs of total stroke were 1.344 (1.151-1.570) for those started smoking at age less than 20 years, 1.254 (1.090-1.443) for those started smoking at age 20-30 years, and 1.205 (1.012-1.435) for those started smoking at age 30 year and above, with a dose-response relation (P for trend, 0.004). Comparing former smokers to current smokers, in the low pack-year group, those stopped smoking at age less than 65 years had a 18.2% decreased risk for total stroke (0.818; 0.673-0.994). The decreased risk was not found in those stopped smoking at age 65 years and above. Similar results were observed in the high pack-year group. In conclusion, we found that current smokers had a higher stroke risk than never smokers, and the risk increased with a younger age at smoking initiation. Smoking cessation can reduce the risk for stroke, especially could benefit from cessation at a younger age.

Residential greenness and dyslipidemia risk: Dose-response relations and mediation through BMI and air pollution.

BACKGROUND: Evidence on associations of residential greenness with dyslipidemia is limited, particularly regarding dose-response relations and mediation. OBJECTIVES: To investigate associations between greenness and dyslipidemia, non-linear dose-response relationships and mediators. METHODS: This cross-sectional study draws on the 2018 Fujian Behavior and Disease Surveillance (FBDS) cohort that used multi-stage stratified random sampling from the general population of Fujian Province, China. Participants with one or more abnormities in total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), or low-density lipoprotein cholesterol (LDL-C) were classified as having dyslipidemia. Residential greenness was operationalized as 3-year average of the normalized difference vegetation index (NDVI500m) and enhanced vegetation index (EVI500m). A doubly robust approach was used for effect quantification. Dose-response relations were studied with natural cubic splines. Mediation via physical activity (PA), body mass index (BMI), PM2.5, PM10, SO2, and NO2 was also examined. RESULTS: Data from 43,183 participants were analyzed. Increases in NDVI500m and EVI500m residential greenness were associated with decreased dyslipidemia risk and improved blood lipids. Non-linear dose response relationships were discovered. Significant reduction of dyslipidemia risk was observed at levels of EVI500m > 0.48 and NDVI500m > 0.65. Joint mediation effects of PA, BMI, PM2.5, PM10, NO2, and SO2 on the associations of NDVI500m and EVI500m with dyslipidemia risk were 49.74% and 44.64%, respectively. CONCLUSIONS: Increased residential exposure to greenness was associated with decreased risk of dyslipidemia. A non-linear dose-response relationship between greenness and dyslipidemia suggests that specific thresholds of greenness need to be reached in order to achieve effects. BMI, PM2.5, and PM10 partially mediated the association.

Dose-Response Relationship Between Oral Lutein Intake and Plasma Lutein Concentration: A Randomized Controlled Trial.

Lutein was shown to provide health benefits for a few diseases. The dose-response relation of oral lutein intake in humans has rarely been reported. The objective is to investigate the dose-response relation between oral lutein intake and plasma lutein concentration in humans. Forty subjects were recruited from Qingdao University, China in 2014. The subjects were randomly divided into four groups: (1-3) consuming 10, 20, or 40 mg lutein by one, two, or four capsules of lutein A, respectively; (4) consuming 20 mg lutein by two capsules of lutein B (containing 280 mg n-3 fatty acid). After a single oral dose, plasma lutein concentrations were measured at 9-time points. The raise of plasma lutein concentration by a 40 mg dose was significantly higher than by a 10 or 20 mg dose. Plasma lutein concentrations were not significantly different between taking 20 mg lutein A and 20 mg lutein B. A dose-response relation was demonstrated between oral lutein administration and plasma lutein concentration. The dose-response relation was more pronounced among men. The current work provides a scientific basis for recommending a dietary intake level of lutein. Future work should validate the results in other ethnic and age groups.

Associations between school bullying and anxiety in children and adolescents from an ethnic autonomous county in China.

School bullying is a widespread public health issue that negatively impacts the mental health of children and adolescents. This study aimed to investigate associations between school bullying involvement and anxiety of children and adolescents. A survey covering all types of pre-college schools (primary, middle, high, and vocational school) was conducted in an ethnic autonomous county in China. 1,943 students participated in this study. Being a victim of verbal (OR=3.08, 95%CI = [2.43,3.91]), physical (OR=3.24, 95%CI = [2.46,4.27]), relational (OR=3.72, 95%CI = [2.90,4.76]), or cyberbullying (OR=3.47, 95%CI = [2.61,4.61]) were associated with increased symptoms of generalized anxiety. Similarly, being a perpetrator of verbal (OR=2.12, 95%CI = [1.45,3.10]), physical (OR=1.85, 95%CI = [1.22,2.79]), relational (OR=1.78, 95%CI = [1.15,2.74]), or cyber-bullying (OR=1.59, 95%CI = [1.08,2.33]) were related to a higher degree of anxiety. Moreover, in both victims and perpetrators higher levels of anxiety were associated with a greater number of types of bullying they were involved in, suggesting a dose-response relation between school bullying involvement and anxiety. Therefore, both bullying victims and perpetrators need mental health support and anti-bullying strategies should address different forms of bullying evenhandedly.

Association between Sedentary Time and 6-Year All-Cause Mortality in Adults: The Rural Chinese Cohort Study.

OBJECTIVES: This study aims to prospectively explore the association between sedentary time and the risk of all-cause mortality in adults based on a cohort from rural areas of China. METHODS: The study population included 20,194 adults at baseline (2007-2008) who participated in the Rural Chinese Cohort Study. Cox's proportional hazard regression model was used to analyze the hazard ratios (HRs) and 95% confidence intervals (CIs) of sedentary time and all-cause mortality, and a restricted cubic spline was used to model the dose-response relation. We also carried out a series of sensitivity analyses to verify the robustness of our main results. RESULTS: The median follow-up duration was 6 years, with a total of 17,265 participants (response rate 85.5%) followed up, and 1,106 deaths observed. Data for 17,048 participants were analyzed, with the mean age of participants being 52.00. Compared with sedentary time <4 h/day group, the risk of all-cause mortality was significantly increased in the 8-11 h/day (HR=1.27, 95%CI:1.03-1.56) and ≥11 h/day groups (HR=1.48, 95%CI:1.20-1.84). With increases in sedentary time, the risk of all-cause mortality increased gradually (Ptrend <0.001). For each 1 h/day increase in sedentary time, the risk of all-cause mortality increased by 3% (HR=1.03, 95%CI: 1.01-1.05). Sensitivity analyses showed our main results were consistent. CONCLUSIONS: Prolonged sedentary time increases the risk of all-cause mortality in the adult rural Chinese population. Reducing sedentary time may have important implications for reducing mortality risk.

Dose-Response Reduction in Risk of Nasopharyngeal Carcinoma From Smoking Cessation: A Multicenter Case-Control Study in Hong Kong, China.

BACKGROUND: Cigarette smoking is associated with nasopharyngeal cancer (NPC) risk. Whether quitting reduces the risk is unclear. We investigated the associations of NPC with duration of and age at quitting in an endemic region. METHODS: We investigated the associations between NPC and quitting in a multicenter case-control study in Hong Kong with 676 newly diagnosed NPC cases and 1,285 hospital controls between 2014 and 2017, using a computer-assisted self-administered questionnaire. Multivariable unconditional logistic regression yielded adjusted odds ratios (AORs) of NPC by quitting status, duration and age of quitting, combinations of duration and age of quitting, and quitting to smoking duration ratio, compared with current smoking. RESULTS: Quitting (AOR: 0.72; 95% CI: 0.53-0.98) and never smoking (0.73, 0.56-0.95) were associated with lower NPC risk. NPC risk decreased with (i) longer quitting duration (p < 0.01), reaching significance after 11-20 (0.62, 0.39-0.99) and 21+ years (0.54, 0.31-0.92) of quitting; (ii) younger quitting age (p = 0.01), reaching significance for quitting at <25 years (0.49, 0.24-0.97); and (iii) higher quitting to smoking duration ratio (p < 0.01), reaching significance when the ratio reached 1 (0.60, 0.39-0.93). Quitting younger (age <25) appeared to confer larger reductions (49% for ≤10 years of quitting, 50% for 11+ years) in NPC risk than quitting at older ages (25+) regardless of quitting duration (16% for ≤10 years, 39% for 11+ years). CONCLUSIONS: We have shown longer duration and younger age of quitting were associated with lower NPC risk, with dose-response relations. Our findings support including smoking as a cause of NPC. Stronger tobacco control measures and quitting services are needed to prevent NPC.

The Effect and Mechanism of Cholesterol and Vitamin B12 on Multi-Domain Cognitive Function: A Prospective Study on Chinese Middle-Aged and Older Adults.

Background: Nutrients are associated with cognitive function, but limited research studies have systematically evaluated on multi-domain cognitive function. The aim of this study was to investigate the effect and mechanism of specific nutrient on multi-domain cognitive function, and provide nutrition guidance for improving cognitive function. Methods: Participants were selected based on a multicenter prospective study on middle-aged and older adults in China. Global cognitive function was evaluated by the Mini-Mental State Examination (MMSE). Nutrients intake was assessed according to food frequency questionnaire and China Food Composition Database, and principal component analysis was performed to extract nutrient patterns. Associations between specific nutrients and cognitive function were assessed using log-binomial regression. Restricted cubic spline was used to illustrate the dose-response relationship of nutrients with multi-domain cognitive function. Mediation analysis was used to determine the mechanism of nutrients in cognitive function. Results: Four nutrient patterns were identified (vitamin-mineral, protein-carbohydrate, fatty acid-vitamin E, and cholesterol-vitamin B12), and only a nutrient pattern rich in cholesterol and vitamin B12 was found associated with cognitive function (RR = 0.891, 95%CI = 0.794-0.999). In multi-domain cognitive function, dietary cholesterol and vitamin B12 were related to better performance of visual memory function (P = 0.034, P = 0.02). In dose-response relationship, it suggested a U-shaped association between vitamin B12 and MMSE (P = 0.02) within a certain range. Conclusions: Dietary intake rich in cholesterol and vitamin B12 was associated with better cognitive function, and vitamin B12 had a U-shaped dose-response relation with MMSE. Thus, ensuring moderate cholesterol and vitamin B12intake may be an advisable strategy to improve cognitive function in middle-aged and older adults. Clinical Trial Registration: EMCOA, ChiCTR-OOC-17011882, Registered 5th, July 2017-Retrospectively registered, http://www.medresman.org/uc/project/projectedit.aspx?proj=2610.

Dose-response Relation Deduced for Coronaviruses From Coronavirus Disease 2019, Severe Acute Respiratory Syndrome, and Middle East Respiratory Syndrome: Meta-analysis Results and its Application for Infection Risk Assessment of Aerosol Transmission.

BACKGROUND: A comprehensive understanding of the transmission routes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of great importance to effectively control the spread of coronavirus disease 2019 (COVID-19). However, the fundamental dose-response relation is missing for evaluation of the infection risk. METHODS: We developed a simple framework to integrate the a priori dose-response relation for SARS-CoV-2 based on mice experiments, the recent data on infection risk from a meta-analysis, and respiratory virus shedding in exhaled breath to shed light on the dose-response relation for humans. The aerosol transmission infection risk was evaluated based on the dose-response model for a typical indoor environment. RESULTS: The developed dose-response relation is an exponential function with a constant k in the range of about 6.4 × 104 to 9.8 × 105 virus copies, which means that the infection risk caused by 1 virus copy in viral shedding is on the order of 10-6 to 10-5. The median infection risk via aerosol transmission with 1-hour exposure (10-6 to 10-4) was significantly lower than the risk caused by close contact (10-1) in a room with an area of 10 to 400 m2 with 1 infected individual in it and with a typical ventilation rate of 1 air change per hour. CONCLUSIONS: The infection risk caused by aerosol transmission was significantly lower than the risk caused by close contact. It is still necessary to be cautious for the potential aerosol transmission risk in small rooms with prolonged exposure duration.

Associations of perceived indoor environmental quality with stress in the workplace.

Indoor environmental quality (IEQ) is a general indicator of the quality of conditions inside a building. We investigated associations of perceived IEQ including air quality, thermal comfort, noise, and light quality with stress at work and the extent to which workplace location modifies these associations. We recruited 464 full-time workers from four companies in Singapore. Data on socio-demographic characteristics, lifestyle/health-related factors, and workplace factors were collected through self-administered questionnaires. Perceived IEQ satisfaction scores of all four factors were collected using the validated OFFICAIR questionnaire. We fitted a logistic regression model to assess associations between each perceived IEQ score and stress at work, adjusting for potential confounders. The odds ratio for stress at work associated with a 1-unit increase in perceived air quality score was 0.88 (0.82-0.94), 0.89 (0.82-0.97) for thermal comfort, 0.93 (0.87-0.98) for noise, and 0.88 (0.82-0.94) for light quality. Significant associations were found in office and control rooms for all four perceived IEQ, except for thermal comfort in office rooms. Higher satisfaction levels of perceived air quality, thermal comfort, noise, and lighting, were significantly associated with a reduction in stress at work. Our findings could potentially provide a useful tool for environmental health impact assessment for buildings.

Dietary saturated fat intake and risk of stroke: Systematic review and dose-response meta-analysis of prospective cohort studies.

BACKGROUND AND AIMS: Because of the conflicting research results, the association between saturated fatty acid (SFA) consumption and the risk of stroke remains controversial. We conducted a meta-analysis to evaluate potential dose-response relation between SFA intake and stroke. METHODS AND RESULTS: PubMed, Embase, the Cochrane Library Central Register of Controlled Trials, and Web of Science were searched. Summary relative risks (RRs) of the highest vs. the lowest category of SFA intake and their 95% confidence intervals (CIs) were pooled by random-effects models. Linear or nonlinear dose-response trend estimations were evaluated with data from categories of SFA consumption in each study. Fourteen studies involving a total of 598,435 participants were eligible for high vs. low meta-analysis, and 12 studies involving a total of 462,268 participants were eligible for the dose-response relation assessment. Higher dietary SFA intake was associated with a decreased overall risk for stroke (RR, 0.87; 95% CI, 0.78-0.96; I2 = 37.8%). A linear relation between SFA and stroke was explored (P = 0.01), the pooled RR of stroke per 10 g/day increase in SFA intake was 0.94 (95% CI, 0.89-0.98; P = 0.01). CONCLUSION: This meta-analysis further demonstrated that a higher consumption of dietary SFA is associated with a lower risk of stroke, and every 10 g/day increase in SFA intake is associated with a 6% relative risk reduction in the rate of stroke. Further research is needed to explore the influence of specific SFA types and different macronutrient replacement models of SFA on the stroke risk.

Dose-response association between sleep duration and obesity risk: a systematic review and meta-analysis of prospective cohort studies.

The association between sleep duration and obesity risk remains unclear. We performed an updated meta-analysis to quantify a potential dose-response relation between sleep duration and risk of obesity. PubMed and Embase were searched for prospective cohort studies examining the association between sleep duration and risk of obesity that were published up to October 28, 2017. Random effects models were used to evaluate the pooled relative risks (RRs) and 95% confidence intervals (CIs) for the association of sleep duration and obesity. Restricted cubic splines were used to model the dose-response association. The meta-analysis included 12 studies (16 reports). We found a reverse J-shaped relation between sleep duration and obesity, with the lowest risk at 7-8-h sleep per day. Compared with 7-h sleep duration per day, the pooled relative risks for obesity were 1.09 (95% CI 1.05-1.14) for each 1-h decrement among individuals who slept < 7 h per day and 1.02 (95% CI 0.99-1.05) for each 1-h increment of sleep duration among individuals with longer sleep duration. Short sleep duration significantly increased the risk of obesity. Compared with 7-h sleep duration per day, the risk of obesity increases 9% for each 1-h decrease in sleep duration.

Evolutionarily adapted hormesis-inducing stressors can be a practical solution to mitigate harmful effects of chronic exposure to low dose chemical mixtures.

Although the toxicity of synthetic chemicals at high doses is well known, chronic exposure to low-dose chemical mixtures has only recently been linked to many age-related diseases. However, it is nearly impossible to avoid the exposure to these low-dose chemical mixtures as humans are exposed to a myriad of synthetic chemicals as a part of their daily lives. Therefore, coping with possible harms due to low dose chemical mixtures is challenging. Interestingly, within the range of environmental exposure, disease risk does not increase linearly with increasing dose of chemicals, but often tends to plateau or even decrease with increasing dose. Hormesis, the over-compensation of various adaptive responses through cellular stresses, is one possible mechanism for this non-linearity. Although the hormetic effects of synthetic chemicals or radiation have long been debated in the field of toxicology, the hormesis concept has recently been generalized in the field of molecular biology; similar to responses to synthetic chemicals, mild to moderate intermittent stressors from any source can induce hormetic responses. Examples of stressors are exercise, calorie restriction, intermittent fasting, cognitive stimulation, and phytochemicals. Mitohormesis is hormesis induced by such stressors through mitochondrial retrograde signalling including the increased production of mild reactive oxygen species. Xenohormesis is phytochemical-induced hormesis, reflective of a mutualistic relationship between plant and animals. As humans had repeated exposure to all of these stressors during their evolution, the hormetic effects of these health behaviours may be considered to be evolutionarily adapted. Although hormesis induced by synthetic chemicals occurs in humans, such hormesis may not be recommended to the public due to unresolved issues on safety including the impossibility of control exposure. However, the use of personal health behaviors which enhance mitohormetic- or xenohormetic-stress can be readily incorporated into everyone's daily lives as a practical way to counteract harmful effects of unavoidable low-dose chemical mixtures.

Estimations of the lethal and exposure doses for representative methanol symptoms in humans.

BACKGROUND: The aim of this review was to estimate the lethal and exposure doses of a representative symptom (blindness) of methanol exposure in humans by reviewing data from previous articles. METHODS: Available articles published from 1970 to 2016 that investigated the dose-response relationship for methanol exposure (i.e., the exposure concentration and the biological markers/clinical symptoms) were evaluated; the MEDLINE and RISS (Korean search engine) databases were searched. The available data from these articles were carefully selected to estimate the range and median of a lethal human dose. The regression equation and correlation coefficient (between the exposure level and urinary methanol concentration as a biological exposure marker) were assumed from the previous data. RESULTS: The lethal human dose of pure methanol was estimated at 15.8-474 g/person as a range and as 56.2 g/person as the median. The dose-response relationship between methanol vapor in ambient air and urinary methanol concentrations was thought to be correlated. An oral intake of 3.16-11.85 g/person of pure methanol could cause blindness. The lethal dose from respiratory intake was reported to be 4000-13,000 mg/l. The initial concentration of optic neuritis and blindness were shown to be 228.5 and 1103 mg/l, respectively, for a 12-h exposure. CONCLUSION: The concentration of biological exposure indices and clinical symptoms for methanol exposure might have a dose-response relationship according to previous articles. Even a low dose of pure methanol through oral or respiratory exposure might be lethal or result in blindness as a clinical symptom.

Factors of concern in a human 3D cellular airway model exposed to aerosols of nanoparticles.

Mucilair 3D bronchial airway models, cultured at an air-liquid interface, were exposed to aerosols of copper oxide (CuO) nanoparticles in Vitrocell air exposure modules. Four cell donors, four exposure modules and four exposure concentrations were varied within four different exposure sessions using a statistical experimental design called a hyper-Graeco-Latin square. Analysis of variance techniques were used to investigate the effects of these factors on release and RNA expression of inflammation markers monocyte chemoattractant protein-1 (MCP-1) interleukines 6 and 8 (IL-6 and IL-8) an cytotoxicity marker lactate dehydrogenase (LDH) determined 24h after exposure. The same techniques were also used to conduct a global analysis on RNA expressions of 10,000 genes. There were no major signs of cytotoxicity. Release of IL-6 and MCP-1 was affected by CuO concentration, and, for MCP-1, by donor variation. IL-8 release was not affected by these factors. However, gene expression of all three inflammation markers was strongly affected by CuO concentration but not by the other factors. Further, among the 10,000 genes involved in the global analysis of RNA expression, 1736 were affected by CuO concentration, 704 by donor variation and 269 by variation among exposure sessions. The statistical design permitted the assessment of the effect of CuO nanoparticles on 3D airway models independently of technical or experimental sources of variation. We recommend using such a design to address all potential sources of variation. This is especially recommended if test materials are expected to be less toxic than CuO, because the variation among the concentration levels could then be close to the variation among donors or exposure sessions.

Cumulative childhood maltreatment and its dose-response relation with adult symptomatology: Findings in a sample of adult survivors of sexual abuse.

In the present study, we examined the role of cumulative childhood maltreatment experiences for several health related outcomes in adulthood, including symptoms of psychological distress as well as perceived social support and hardiness. The sample comprised adult survivors of sexual abuse (N=278, 95.3% women, mean age at first abusive incident=6.4 years). One-way ANOVAs revealed a statistically significant dose-response relation between cumulative childhood maltreatment scores and self-reported symptoms of posttraumatic stress (PTSS), anxiety, depression, eating disorders, dissociation, insomnia, nightmare related distress, physical pain, emotional pain, relational problems, self-harm behaviors as well as on a measure of symptom complexity. Cumulative childhood maltreatment was also associated with lower levels of work functioning. An inverse dose-response relation was found for perceived social support and hardiness. Using a Bonferroni corrected alpha level, cumulative childhood maltreatment remained significantly associated with all outcome measures with the exception of eating disorder symptoms after controlling for abuse-related independent variables in hierarchical regression analyses. Results add to previous literature by showing that dose-response relation between cumulative childhood adversities and adult symptom outcomes could also be identified in a sample characterized by high exposure to adversities, and lends support to the notion put forth by previous authors that cumulative childhood adversities seem to be related to the severity of adult health outcomes in a rule-governed way.

Estimations of the lethal and exposure doses for representative methanol symptoms in humans

BACKGROUND: The aim of this review was to estimate the lethal and exposure doses of a representative symptom (blindness) of methanol exposure in humans by reviewing data from previous articles. METHODS: Available articles published from 1970 to 2016 that investigated the dose-response relationship for methanol exposure (i.e., the exposure concentration and the biological markers/clinical symptoms) were evaluated; the MEDLINE and RISS (Korean search engine) databases were searched. The available data from these articles were carefully selected to estimate the range and median of a lethal human dose. The regression equation and correlation coefficient (between the exposure level and urinary methanol concentration as a biological exposure marker) were assumed from the previous data. RESULTS: The lethal human dose of pure methanol was estimated at 15.8–474 g/person as a range and as 56.2 g/person as the median. The dose-response relationship between methanol vapor in ambient air and urinary methanol concentrations was thought to be correlated. An oral intake of 3.16–11.85 g/person of pure methanol could cause blindness. The lethal dose from respiratory intake was reported to be 4000–13,000 mg/l. The initial concentration of optic neuritis and blindness were shown to be 228.5 and 1103 mg/l, respectively, for a 12-h exposure. CONCLUSION: The concentration of biological exposure indices and clinical symptoms for methanol exposure might have a dose-response relationship according to previous articles. Even a low dose of pure methanol through oral or respiratory exposure might be lethal or result in blindness as a clinical symptom.

Dose-response relationship of anhydrous alcohol for thoracic sympathetic block in treating primary palmar hyperhidrosis / 中华麻醉学杂志

Objective To determine the dose-response relationship of anhydrous alcohol for thorac-ic sympathetic block in treating primary palmar hyperhidrosis. Methods Two hundred patients with prima-ry palmar hyperhidrosis, aged 18-33 yr, grade of palmar sweating 3 or 4, scheduled for elective surgery under thoracic sympathetic block, were divided into 5 different mixture of anhydrous alcohol and iohexol (iohexol : anhydrous alcohol=1 : 5)groups(n=40 each)using a random number table. Under CT guid-ance, thoracic intervertebral puncture was performed between T3and T4until the needle tip reached the spot around T4and above capitis costae. The mixture of anhydrous alcohol 10 ml(group R1), 15 ml(group R2), 20 ml(group R3), 25 ml(group R4)and 30 ml(group R5)and iohexol was injected into the thoracic sympathetic ganglia on both sides. Effective block was defined as the rise in the palm tempera-ture of both hands more than 3℃ and sweating completely disappeared at 10 min after thoracic sympathetic block was performed with anhydrous alcohol. The median effective dose(ED50), ED95and 95% confi-dence interval(CI)of anhydrous alcohol for thoracic sympathetic block in treating primary palmar hyper-hidrosis were calculated by probit analysis. Results The ED50(95% CI)of anhydrous alcohol for thorac-ic sympathetic block in treating primary palmar hyperhidrosis was 1882(1564-2201)ml, and the ED95 (95% CI)was 2806(2420-3812)ml. Conclusion The ED50and ED95of anhydrous alcohol for tho-racic sympathetic block in treating primary palmar hyperhidrosis are 1882 and 2806 ml, respectively.

Time-dependent dose-response relation for absence of vaginal elasticity after gynecological radiation therapy.

BACKGROUND AND PURPOSE: To investigate the dose-response relation between the dose to the vagina and the patient-reported symptom 'absence of vaginal elasticity' and how time to follow-up influences this relation. MATERIAL AND METHODS: The study included 78 long-term gynecological cancer survivors treated between 1991 and 2003 with external beam radiation therapy. Of those, 24 experienced absence of vaginal elasticity. A normal tissue complication model is introduced that takes into account the influence of time to follow-up on the dose-response relation and the patient's age. The best estimates of the dose-response parameters were calculated using Probit, Probit-Relative Seriality (RS) and Probit-time models. Log likelihood (LL) values and the Akaike Information Criterion (AIC) were used to evaluate the model fit. RESULTS: The dose-response parameters for 'absence of vaginal elasticity' according to the Probit and Probit-time models with the 68% Confidence Intervals (CI) were: LL=-39.8, D50=49.7 (47.2-52.4) Gy, γ50=1.40 (1.12-1.70) and LL=-37.4, D50=46.9 (43.5-50.9) Gy, γ50=1.81 (1.17-2.51) respectively. CONCLUSIONS: The proposed model, which describes the influence of time to follow-up on the dose-response relation, fits our data best. Our data indicate that the steepness of the dose-response curve of the dose to the vagina and the symptom 'absence of vaginal elasticity' increases with time to follow-up, while D50 decreases.

Dose-response Relation and Synergy Effects of Bioactive Components in Ginkgo biloba on Antiplatelet Aggregation and DPPH Free Radical Scavenging / 世界科学技术-中医药现代化

This study was aimed to investigate the dose-response relations and synergy effects of bioactive components in Ginkgo bilobaon antiplatelet aggregation and DPPH free radical scavenging.The antiplatelet aggregation experiment and DPPH free radical scavenging experiment were conducted respectively to investigate the dose-response relations and synergy effects.Firstly,the effect of inhibiting platelet aggregation induced by PAF of ginkgolides in rabbits was investigated.And then,the effect of DPPH free radical scavenging by ginkgo flavonoids was also investigated.Finally,the synergy effects among effective components were studied.The results showed that ginkgolide A,ginkgolide B,ginkgolide C and bilobalide had dose-response relations on antiplatelet aggregation.Quercetin,kaempferol and isorhamnetin had DPPH free radical scavenging effects with dose-response relation.It was concluded that ginkgolide had the dose-response relation on antiplatelet aggregation.Ginkgolide A and ginkgolide B had synergy effect.Ginkgo flavonoids had DPPH free radical scavenging effect.Quercetin and isorhamnetin had synergy effect.