[Associations between indoor volatile organic compounds and nocturnal heart rate variability of young female adults: A panel study]

OBJECTIVE

To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults.

METHODS

This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results.

RESULTS

The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m². During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m³, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m³, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m³ increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m³. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter.

CONCLUSION

Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.

[One-stage revision using intra-articular vancomycin infusion effectively treats chronic prosthetic joint infection caused by Enterococcal]

Objective: To investigate the clinical effects of one-stage revision combined with intra-articular infusion of vancomycin in the treatment of chronic prosthetic joint infection (PJI) caused by Enterococcal. Methods: From May 2013 to June 2020,the clinical data of 9 patients (2 males and 7 females) with chronic Enterococcal PJI treated with one-stage revision using intra-articular infusion of vancomycin at Department of Orthopaedics,First Affiliated Hospital of Xinjiang Medical University were retrospectively analyzed,including 8 hips and 1 knee.A total of 9 patients with age of (63.9±11.7)years (range:43 to 76 years) were included, and the body mass index was (23.6±4.3)kg/m² (range:18 to 30 kg/m²).There were 6 cases with antibiotic history and 5 cases with sinus tract.The joint fluid,infected tissue around the prosthesis and ultrasonic shock fluid of the prosthesis were collected during operation for microbial culture identification and drug sensitivity test.After thorough debridement of the infected site and removal of the infected prosthesis,a new prosthesis was implanted,then the drainage tube in the operation area was placed.After surgery,vancomycin(1.0 g,q12 h) was combined with intra-articular vancomycin(0.5 g,qd) in monomicrobial PJI,and vancomycin(1.0 g,q12 h) was combined with intra-articular vancomycin (0.5 g,qd) and imipenem/meropenem (0.5 g,qd),and the interval between the two drugs was 12 hours in polymicrobial PJI.Hip and knee functions were evaluated by Harris Hip Score or Knee Society Score(KSS),respectively.The comparison of hip function scores before and after operation was performed by paired t-test. Results: All patients were followed up for (60±39)months(range:24 to 110 months).Two cases were infected with Enterococcus faecium and 7 cases were infected with Enterococcus faecalis.There were 7 cases of monomicrobial infection and 2 cases of polymicrobial infection.Erythromycin(5/9),tetracycline(4/9),ciprofloxacin and β-lactam antibiotics(3/9) were the top three antibiotics in Enterococci resistance rate.The sensitive antibiotics for Enterococcal were vancomycin,linezolid and tigecycline.The average duration of intravenous antibiotics was (14±1)days (range:13 to 17 days),and the average duration of antibiotics in articular cavity was (15±2)days(range:11 to 20 days).Mean duration of oral antibiotic use after discharge was (2±1)months(range:1 to 3 months).One case of polymicrobial PJI treatment failed,with a failure rate of 1/9.At last follow-up,the Harris score of patients with hip PJI increased from (43±6)points to (84±6)points(t=-11.899, P<0.01). KSS score of knee function was improved from 33 point pre-operatively to 85 point post-operatively;overall function score was improved from 35 point pre-operatively to 80 point post-operatively.During the treatment,no formation of sinus tract of the hip joint caused by a catheter,skin necrosis at the knee puncture site or leakage of joint fluid;no complications such as deep vein thrombosis and pulmonary embolism occurred. Conclusions: One-stage revision combined with intra-articular infusion of vancomycin can achieve acceptable infection control rate and joint function in patients with chronic Enterococcus PJI.However,the treatment of polymicrobial PJI still needs to be further verified.

[Association of ambient fine particulate air pollution with hospitalization costs and stays for depression in China: a multicity analysis]

Objective: To explore the effect of fine particulate matter (PM_2.5) pollution on depression hospitalization cost and length of stay in 57 cities of China. Methods: A total of 84 207 patients with depression in 57 cities of China from January 2013 to December 2017 were selected as the subjects. The demographic characteristics and hospitalization status of the patients were obtained from the database of basic medical insurance for urban workers and urban residents in China. The environmental exposure data of the same period were obtained from the national air quality real-time release platform of China Environmental Monitoring Station. A generalized additive model based on quasi-Poisson distribution was used to analyze PM_2.5 exposure effect in each city, and the nonlinear mixing of moving average temperature, relative humidity and date was controlled by natural smooth spline function. Results: Among the included cities, southern cities accounted for 50.88% (29), and the number of female inpatients, hospitalization costs and hospitalization days accounted for 62.65%, 63.50% and 60.85% (42 735 cases, 567.78 million yuan and 1.14 million days, respectively). The proportion of hospitalized cases, hospitalization cost and length of stay in the age group of 40 to 64 years old were 59.15% (40 346 cases), 53.92% (482.15 million yuan) and 52.07% (0.98 million days), respectively. PM_2.5 level was positively correlated with the number of hospitalized cases with depression, hospitalization cost and length of stay. When the 3-day moving average of PM_2.5 exposure level increased by 10 μg/m³, the number of hospitalization cases increased by 0.64%. The attributed percentage (95%CI) of hospitalized cases, hospitalization costs and length of stay were 3.35% (0.57%-6.04%), 3.04% (0.52%-5.48%) and 3.07% (0.49%-5.56%), respectively. Subgroup analysis showed that the attributed percentage of hospitalization cases, hospitalization cost and length of stay to PM_2.5 exposure ranged from 3.97% to 4.68%, 4.04% to 4.33% and 4.13% to 4.30% in northern China, male and cold season, respectively. Conclusion: PM_2.5 exposure is associated with the increase of hospitalization cost and length of stay among Chinese urban population with depression.

[Analysis of emergency venous sinus stenting in the treatment of acute visual impairment caused by idiopathic cranial hypertension]

Objective: To investigate the efficacy and safety of emergency venous sinus stenting in the treatment of acute visual impairment caused by idiopathic intracranial hypertension (IIH). Methods: A descriptive cross-sectional study design was used to retrospectively analyze 38 patients undergoing venous sinus stenting in the First Affiliated Hospital of Zhengzhou University from January 2013 to October 2019. A total of 9 patients who had sudden short-term vision loss met the inclusion criteria. Routine visual field and fundus examination were performed. The venous sinus stenosis (CVSS) was confirmed by MR venography or DSA. The pressure gradient at both ends of CVSS was ≥10 mmHg(1 mmHg=0.133 kPa). All patients were treated with emergency venous sinus stenting. Six-month follow-up data were collected for comparison, evaluation of the therapeutic effect, and observation of adverse reactions. Results: All 9 patients were successfully treated with venous sinus stent. The pressure gradient at the distal and proximal ends of the stenosis after stent implantation decreased to (2.3±1.2) mmHg. After 6 months of follow-up, the papilledema was significantly improved or disappeared in all patients. The average grade of papilledema decreased from 2.44±0.73 before operation to 0.56±0.53 after treatment (t=6.314, P<0.001). The visual acuity of 9 patients recovered to the pre-onset level or improved significantly after 6 months. The average baseline value of preoperative visual acuity (logMAR) was 0.12±0.11, which increased to 0.74±0.13 on average 6 months after operation (t=-10.827, P<0.001). No recurrence of symptoms or serious adverse reactions occurred in all patients during the follow-up period. Conclusion: For patients with acute visual impairment caused by idiopathic cranial hypertension, emergency venous sinus stenting is a relatively safe and effective treatment that can effectively improve visual acuity.

[Monitoring metrics for short-term exposure to ambient ozone and pulmonary function and airway inflammation in healthy young adults]

OBJECTIVE

To assess the associations of different monitoring metrics for short-term exposure to ambient ozone (O₃) with pulmonary function and airway inflammation in healthy young adults.

METHODS

A total of 97 healthy young college students were recruited and followed in a panel study conducted from December 2017 to June 2018. Each participant underwent 3 follow-up visits, and lung function and fractional exhaled nitric oxide (FeNO) were measured at each visit. Ambient air pollutant concentrations were obtained from the environment monitoring station of Beijing closest to the participant residences, and meteorological data were collected from China Meteorological Data Service Center. Linear mixed-effect models were applied to assess the associations between different monitoring metrics for ambient O₃ short-term exposure with pulmonary function or airway inflammation in the healthy young adults.

RESULTS

During the study period, the P₅₀ (P₂₅, P₇₅) values for ambient O₃ concentration expressed as daily 1-hour maximum (O₃-1 h max), daily maximum 8-hour average (O₃-8 h max) and 24-hour average (O₃-24 h avg) were 102.5 (76.8, 163.0) μg/m³, 91.1 (68.3, 154.3) μg/m³ and 61.6 (36.9, 81.7) μg/m³, respectively. The different monitoring metrics for short-term exposure to ambient O₃ were significantly associated with reduced forced expiratory volume in the first second (FEV₁) and increased FeNO. An interquartile range (IQR) increase in 6-d moving average of O₃-1 h max (IQR=71.5 μg/m³) was associated with a 6.2% (95%CI: －11.8%, －0.5%) decrease in FEV₁ and a 63.3% (95%CI: 13.8%, 134.3%) increase in FeNO. An IQR increase in 7-d moving average of O₃-8 h max (IQR=62.0 μg/m³) was associated with a 6.2% (95%CI: －11.6%, －0.7%) decrease in FEV₁and a 75.5% (95%CI: 19.3%, 158.0%) increase in FeNO. An IQR increase in 5-d moving average of O₃-24 h avg (IQR=32.9 μg/m³) was associated with a 3.7% (95%CI: －7.1%, －0.2%) decrease in FEV₁and a 25.3% (95%CI: 3.6%, 51.6%) increase in FeNO. There was no significant association between the three monitoring metrics for O₃ exposure and peak expiratory flow (PEF).

CONCLUSION

Short-term exposure to ambient O₃ was associated with decreased lung function and increased airway inflammation among the healthy young adults, and daily 1-hour maximum was more sensitively to the respiratory effects of O₃.

[Short-term effects of household indoor- and outdoor-originating fine particulate matters on heart rate and heart rate variability in chronic obstructive pulmonary diseases patients, Beijing]

Objective: To assess the associations of indoor fine particulate matter (PM(2.5)) from outdoor and indoor sources with heart rate (HR) and heart rate variability (HRV) in patients with chronic obstructive pulmonary disease (COPD) of Beijing. Methods: A total of 40 male patients in a stable stage of COPD were recruited from a hospital in a panel study in Beijing with 5 consecutive days of measurement for each subject. General information and disease history of the participants from questionnaires were obtained prior to the study. HR and HRV were repeatedly examined using dynamic electrocardiograph. HRV included standard deviation of all NN intervals (SDNN), root mean square of successive differences between adjacent NN intervals (rMSSD), total power (TP) power in the low-frequency band (LF) and the high-frequency band (HF). Iron was used as tracer element to separate indoor-originated PM(2.5) and outdoor-originated PM(2.5). Mixed-effect models were applied to assess the associations of outdoor-originated PM(2.5) or indoor-originated PM(2.5) and health effects. Results: The P(50) (P(25), P(75)) values of daily indoor PM(2.5), indoor-originated PM(2.5) and outdoor-originated PM(2.5) were 50.9 (26.8, 122.7), 16.0 (1.9, 43.7) and 27.3 (13.5, 61.8) μg/m(3), respectively. The mean±SD of concentrations of real-time indoor PM(2.5), indoor-originated PM(2.5) and outdoor-originated PM(2).5 were (61.5±58.8), (25.3±39.1) and (36.2±42.7) μg/m(3), respectively. Compared with outdoor-originated PM(2.5), indoor-originated PM(2.5) had significant associations with HRV and HR. Each 10 μg/m(3) increase at 4 h indoor-originated PM(2.5) and outdoor-originated PM(2.5) moving average was associated with 3.4% (95%CI: -4.7%, -2.1%) and 0.6% (95%CI: -2.0%, -0.8%) reduction in TP (P<0.001). Each 10 μg/m(3) increase at 12 h indoor-originated PM(2.5) moving average was associated with 7.6% (95%CI: -10.1%, -5.1%), 4.7% (95%CI: -6.7%, -2.7%), 3.3% (95%CI: -4.2%,-2.4%) and 3.0% (95%CI: -4.5%, -1.5%) reduction in HF, LF, SDNN and rMSSD, respectively. Each 10 μg/m(3) increase at 12 h outdoor-originated PM(2.5) moving average was associated with 0.7% (95%CI: -2.7%, -1.4%), 0.2% (95%CI: -1.9%, 1.4%), 0.7% (95%CI: -1.4%, -0.1%) and 0.2% (95%CI: -1.3%, 0.9%) reduction in HF, LF, SDNN and rMSSD, respectively (P<0.001). Each 10 μg/m(3) increase at 8 h indoor-originated PM(2.5) and outdoor-originated PM(2.5) moving average was associated with 0.7% (95%CI: 0.4%, 1.0%) and 0.4% (95%CI: 0.2%, 0.6%) increase in HR. Conclusion: Exposure to indoor-originated PM(2.5) was more strongly associations with HRV indices and HR compared with outdoor-originated PM(2.5) in male COPD patients.

[Effects of high-efficiency particulate air purifiers on indoor fine particulate matter and its constituents in a district of Beijing during winter]

OBJECTIVE

To analyze the effect of domestic high-efficiency particulate air (HEPA) purifiers on the concentrations of indoor fine particulate matter (PM_2.5) and its elementary constituents in 20 residences in a district of Beijing during winter.

METHODS

From November 2015 to January 2016, 20 residences in a district of Beijing were selected, where indoor and outdoor PM_2.5 data were collected simultaneously in three time periods according to the operating of air purifiers (Group 0 h: 24 hours before operating; Group 24 h: 24 hours after operating; Group 48 h: 24 to 48 hours after operating). The content of 21 elements in PM_2.5 samples were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Indoor/outdoor particle concentration ratio (I/O ratios) and ΔI/O ratios were used to describe the pollution levels and the variation range of PM_2.5 and its 21 elementary constituents. One-way analysis of variance (ANOVA) for repeated measurement data was applied to compare the I/O ratios of PM_2.5 and its elementary constituents among the different groups, and Bonferroni method was used for comparison in pairs. Wilcoxon signed rank test for paired-samples was used to compare ΔI/O ratios of 21 elementary constituents with that of PM_2.5.

RESULTS

The median I/O ratios of PM_2.5 in the three groups were 1.27 (P25-P75: 0.50-2.68), 0.45 (P25-P75: 0.27-1.03) and 0.36 (P25-P75: 0.28-2.48), respectively. Compared with Group 0 h, the I/O ratios of PM_2.5 in Group 24 h (P=0.042) and Group 48 h (P=0.006) decreased significantly. However, there was no significant difference between Group 24 h and Group 48 h. Significant differences were found comparing ΔI/O ratios of aluminium, ferrum and titanium to that of PM_2.5, in both Group 24 h and Group 48 h (P<0.05). No significant change was found in the I/O ratios of these three elements among the three groups before and after air purifier operating (P>0.05). Distances from residences to traffic arteries could affect I/O ratios of some elements from traffic-related source (P<0.05).

CONCLUSION

Domestic HEPA air purifiers could effectively reduce indoor PM_2.5 concentration, and the pollution level of PM_2.5 tend to be stable after the purifier operating for a time. The purifiers had different effects on different elements, among which most showed statistical significances.

[The effect of short-term exposure to ambient NO(2) on lung function and fractional exhaled nitric oxide in 33 chronic obstructive pulmonary disease patients]

Objectives: To investigate the effect of short-term exposure to ambient NO(2) has influence on lung function and fractional exhaled nitric oxide (FeNO) in chronic obstructive pulmonary disease (COPD) patients. Methods: A panel of doctor-diagnosed stable COPD patients (n=33) were recruited and repeatedly measured for lung function and FeNO from December 2013 to October 2014. The patients who lived in Beijing for more than one year and aged between 60 and 85 years old were included in the study. We excluded patients with asthma, bronchial tensor, lung cancer and other respiratory disorders other than chronic obstructive pulmonary disease and occupational exposure and chest trauma surgery patients. Because the frequency of each subject visiting to the hospital was different, a total of 170 times of lung function measurements and 215 times of FeNO measurements were conducted. At the same time, the atmospheric NO(2) data of Beijing environmental monitoring station near the residence of each patient during the study period were collected from 1 day to 7 days lag before the measurement. Effects of short-term NO(2) exposure on lung function and FeNO in COPD patients were estimated by linear mixed-effects models. Results: The subjects' forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), peak expiratory flow (PEF), and exhaled NO of subjects were (3.26±0.83) L, (1.66±0.61) L, (4.13±1.77) L/s, and (48.99±14.30) μg/m(3), respectively. The concentration of NO(2) was (70.3±34.2) μg/m(3) and the interquartile range (IQR) was 39.0 μg/m(3). Short-term exposure to NO(2) resulted in a significant decrease in FVC among COPD patients' which was most obvious in 2 days lag. Every quartile range increased in NO(2) (39 μg/m(3), 2 day) would cause a 1.84% (95%CI: -3.20%- -0.48%) reduction in FVC. The effects of exposure to higher concentration of NO(2) (≥58.0 μg/m(3)) on FVC estimate was -2.32% (95%CI: -4.15%- -0.48%)(P=0.02). No significant relevance of FeNO and NO(2) was observed in this study. Conclusions: Short term exposure to ambient NO(2) may bring down pulmonary function in COPD patients.

[Acute effect of air pollutants (carbon monoxide and ozone) on myocardial infarction mortality in Ningbo]

Objective: To explore the effect of carbon monoxide (CO) and ozone (O(3)) in the air on the myocardial infarction mortality in Ningbo, Zhejiang province, from 2011 to 2015. Methods: The data of daily air quality surveillance and the causes of deaths in Ningbo from January 1, 2011 to December 31, 2015 were collected and the time series study using a generalized additive model was conducted to evaluate the relationship between the mortality of myocardial infarction and the air pollutants after adjustment for the long-term trend of death, weather conditions," days of the week" and other confounding factors. Results: The daily average concentrations of CO and O(3) in Ningbo during 2011-2015 were 0.90 (0.02-3.31) mg/m(3) and 82.78 (4-236) μg/m(3), respectively. A total of 5 388 myocardial infarction deaths occurred, with a daily average of 3 deaths. In single-pollutant model, an increase of 0.1 mg/m(3) in average concentration of CO could increase the risk of myocardial infarction mortality by 1.06% (95% CI: 0.29%-1.93%) in general population, and by 1.26% (95% CI:0.28%-2.24%) in aged people aged ≥65 years in lagged 6 days, but the influence was not significant in people aged <65 years. The influence had no significant difference in males, but it increased the risk of myocardial infarction mortality by 1.77% in females (95% CI: 0.44%-3.13%). In multi-pollutant model, CO did remain robust after adjusting for other co-pollutants. Whereas the effect of O(3) had no significant influence. Conclusion: These findings suggested that the increased risk of daily myocardial infarction mortality was associated with the increase of CO concentration, but no such association was found for O(3) in Ningbo.

[Effect of air pollution on health service demand of the elderly and middle-age patients with hypertension, cardiovascular and cerebrovascular diseases: based on analysis of data from CHARLS]

OBJECTIVE

To study the association of air pollution with health service demand of the elderly and middle-age patients with cardiovascular and cerebrovascular diseases, and to provide a scientific basis for development of environmental protection policy and health service policy of the Chinese government.

METHODS

This study included survey data on self-evaluated health, outpatient service demand and inpatient service demand of the patients with hypertension, heart disease and stroke in 62 cities of 17 provinces from China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 2013, and combined it with the data on the annual concentrations of inhalable particulate matter (PM(10)), sulfur dioxide(SO(2)) and nitrogen dioxide (NO(2)) of those provinces and cities. Conditional Logistic regression was carried out to assess the possible effects of air pollutants on self-evaluated health and health service utilization.

RESULTS

The results showed that turning points existed in the effects of concentrations of NO(2) and SO(2) on the health service demand of the patients with hypertension, heart disease and stroke. The inpatient service demand of the hypertension patients increased with NO(2) concentration when it was lower than 35.1 μg/m(3) and decreased with NO(2) concentration for higher value. Self-evaluated health of the patients with heart disease and stroke decreased with SO(2) concentration when it was lower than 63.8 μg/m(3) and increased with SO(2) concentration for higher value. In addition, no evidence was found for the association between PM(10) and health service demand.

CONCLUSION

Air pollution may have effects on health service demand of the patients with hypertension,cardiovascular and cerebrovascular diseases, and different air pollutants at high or low concentration may have different health effects.

Perceptions of public attitudes towards persons with mental illness in Beijing, China: results from a representative survey

OBJECTIVES

Many studies have examined the general public's attitudes towards people with mental illness, but such studies are scarce in China. This study examined the perceptions of the Beijing population regarding their society's prevalent attitudes towards people with mental illness.

METHODS

A total of 5000 individuals aged 18 or above living in Beijing were selected using a multistage, stratified, cluster and random sampling method. This was followed by a face-to-face interview which used a standardized questionnaire asking about societal attitudes towards individuals with mental illness.

RESULTS

4602 out of 5000 eligible individuals met the inclusion criteria and participated in the interview. 4596 questionnaires were deemed valid and included in the analyses. A large proportion of respondents believed that most individuals within their society held negative attitudes and had a strong desire to distance themselves from people with mental illness. Respondents aged 60 or older, who lived farther to downtown Beijing, or with higher education tended to believe that most individuals have relatively positive and tolerant attitudes towards people with mental illness.

CONCLUSIONS

Many people in Beijing perceive that most members of their society have negative beliefs towards people with mental illness. Further efforts are needed to determine if these perceptions are accurate and to reduce the stigma that is reinforced by these perceptions.

[Detection of GLO I phenotypes in blood and blood stains using agarose starch gel electrophoretic analysis]

The distribution of GLO I phenotypes was studied using mixed agarose starch gel electrophoresis in 234 Chinese Han population in Changsha area. Three GLO I phenotypes were detected. The gene frequencies were as follows: GLO I1 = 0.1303 and GLO I2 = 0.8697. The phenotype frequencies of GLO I were compared not only among the different nationalities but with those reported by other countries. Both the 20 bloodstain samples kept at room temperature for 40 days and the other 20 bloodstain samples kept at 4 degrees C for at least 100 days could be correctly phenotyped. Two out of 8 watered bloodstains, their GLO I2-1 phenotype was changed to GLO I2-2. In blind trial, 15 bloodstain samples kept at room temperature for 40 days could be phenotyped correctly.

Dose findings of dihydroartemisinin in treatment of falciparum malaria

Forty patients with uncomplicated P. falciparum malaria were respectively treated in an open randomized comparative study of dihydroartemisinin tablets given at total doses of 480 mg over 5 days and 640 mg over 7 days in a drug-resistant malaria endemic area in Hainan, China. The result showed that all patients were clinically cured. In 5-day and 7-day groups, the mean fever clearance times (FCT) were 26.1+/-10.2 and 21.1+/-11.8 hours respectively; the mean parasite clearance times (PCT) were 58.7+/-20.9 and 59.4+/-20.9 hours respectively, which showed no significant difference. 28-day follow-ups were accomplished on 39 and 37 cases respectively in two groups, the recrudescence rates were 20.5% (8/39) in 5-day group, while 2.7% (1/37) in 7-day group with significant difference (chi2=4.19, p<0.05). No clinical drug-related side effect was found in two groups during treatment.

The infectivity of gametocytes of Plasmodium falciparum from patients treated with artemisinin

Twenty-seven patients with gametocytes of Plasmodium falciparum (PF) were divided into groups A, B, and C. A daily dose of 1200 mg artemisinin was given for 5 days to group A, a state dose of 750 mg of mefloquine to group B and a single dose of 750 mg mefloquine combined with 45 mg primaquine to group C. After treatment, the gametocyte count was taken daily, and infectivity of the gametocytes to Anopheles dirus via membrane feeding was also studied. Results showed that in group A, the density of gametocyte and infectivity were significantly reduced on days 4, 7, 14 and 21 after treatment; In group B, the gametocytes were significantly reduced on days 7, 14 and 21 and infectivity was significantly cut down on days 14 and 21 after medication. In group C, gametocytes disappeared in 5 out of 9 patients with failure of infecting mosquitoes in all 9 patients on day 4 after treatment. These indicate that artemisinin can effectively influence the infectivity of gametocytes of PF. Artemisinin is much better in blocking the transmission of PF malaria than mefloquine.

Clinical trials of artemisinin and its derivatives in the treatment of malaria in China

Since 1979 several derivatives of artemisinin have been synthesized and studied in China. Artemisinin suppositories, artesunate (oral or parenteral), intramuscular artemether and dihydroartemisinin tablets have all proved rapidly effective. In all, 2352 patients (2150 with Plasmodium falciparum and 202 with P. vivax) have been included in clinical trials from our centre. All preparations have been well tolerated. These drugs have now replaced chloroquine and quinine for the treatment of malaria in China.

[The infectivity of gametocytes of Plasmodium falciparum from patients treated with artemisinine]

27 patients with gametocytes of P. falciparum were divided into groups A, B and C. 1,200 mg of artemisinine was given as a daily dose for 5 days to group A, 750 mg of mefloquine plus 45 mg of primaquine as a single dose to group C. After medication, gametocyte count was observed daily in addition to the infectivity of gametocytes of P. falciparum to Anopheles dirus. In group A, the density of gametocytes and the infectivity were significantly reduced on days 4, 7, 14 and 21 during the study. In group B, the density of gametocytes was significantly reduced on days 7, 14 and 21 and the infectivity was obviously lowered on days 14 and 21 after medication. In group C, gametocytes disappeared in 5 out of 9 patients with the failure of infection to mosquitoes on day 4 after treatment. This indicates that artemisinine can effectively influence the infectivity of gametocytes of P. falciparum. Artemisinine is superior to mefloquine in blocking the transmission of P. falciparum malaria.

[Randomised comparison on the treatment of falciparum malaria with dihydroartemisinin and piperaquine]

In 1988, 50 cases each of falciparum malaria were treated by dihydroartemisin (360 mg in 5 days and 480 mg in 7 days respectively), and compared randomly with piperaquine phosphate group. The results showed that the plasmodium of falciparal malaria in Dong Fang County, Hainan province, is much more resistant to piperaquine phosphate, in the 51 cases treated by piperaquine, 33.3% were sensitive, 19.0% were RI, 21.6% were RII, and 25.5% were RIII. The effect of dihydroartemisinin (both 5 days and 7 days therapy) were obviously better than that of pipera quine, fever subsidence time and parasite clearance time were similar and parasite recrudescence rate showed no obvious difference in these two groups too.

Serum ionized calcium, serum and intracellular phosphate, and serum parathormone concentrations in acute malaria

Previous studies have shown depressed serum corrected calcium and phosphate concentrations in acute falciparum malaria. To characterize malaria-associated disturbances in mineral homoeostasis further, serum ionized calcium and intracellular phosphate were measured in 18 patients (10 with falciparum malaria, 8 with vivax malaria) and 10 healthy controls. Six patients (4 falciparum, 2 vivax) had admission serum ionized calcium concentrations below the absolute control range (< 1.15 mmol/litre) and a further six (3 falciparum, 3 vivax) developed ionized hypocalcaemia during treatment. The patients with falciparum malaria had the lowest values at presentation (median [95% confidence intervals in brackets]: 1.17 [1.12-1.23] vs. 1.20 [1.18-1.24] mmol/litre in controls, P = 0.035) in the presence of depressed simultaneous serum parathormone concentrations (1.2 [0.6-1.9] vs. 1.6 [1.1-2.6] pmol/litre; P = 0.05). Admission serum phosphate concentrations were lower in the malaria patients (P = 0.007 vs. controls), especially in those with falciparum malaria (0.85 [0.7-1.1] vs. 1.2 [1.1-1.3] mmol/litre in controls; P = 0.002); patients with falciparum malaria also had significantly lower intracellular phosphate than controls (0.74 [0.58-0.90] vs. 0.88 [0.66-1.04] mmol/litre red cells; P = 0.047). There was a weak association between serum corrected and ionized calcium in the malaria patients (rs = 0.31, n = 18, P > 0.1), but serum and intracellular phosphate correlated significantly (rs = 0.71, n = 17, P < 0.001) with a regression line slope of 0.49 and intercept of 0.27 mmol/litre of red cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Indium inhibits gap junctional communication between rat hepatocytes in primary culture

The effect of indium on gap junctional communication was investigated in primary cultured rat hepatocytes. Treatment of hepatocytes with indium chloride at concentrations of 100 microM to 1 mM for 2 h resulted in dose-dependent inhibition of gap junctional communication between hepatocytes. The effect of indium on hepatocytes was also evaluated using two indices for cell viability: lactate dehydrogenase (LDH) leakage and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction. Indium did not cause any increase in LDH leakage from hepatocytes at the above concentrations, but inhibition of MTT reduction was observed at concentrations above 500 microM. These results suggest that the gap junctions between hepatocytes may be vulnerable sites to indium toxicity.

Pharmacokinetics of the combination pyrimethamine with sulfadoxine and mefloquine (FANSIMEF) in Chinese volunteers and the relative bioavailability of a lacquered tablet

The oral single-dose pharmacokinetics and bioavailability of mefloquine (M) in combination with pyrimethamine (P) and sulfadoxine (S) from a single non-lacquered tablet (NL; M 250 mg, P 25 mg, S 500 mg) and two lacquered tablets (L; M 125 mg, P 12.5 mg, S 250 mg) were investigated in 6 healthy Chinese volunteers. The plasma concentrations of P and S were measured by high-performance liquid chromatography with UV detector over 11 days and the plasma concentrations of M were measured by gas chromatography with electron capture for 63 days. The pharmacokinetic evaluation of each of the three components was based on the assumption of an open linear one-compartment model. The model-independent pharmacokinetic parameters such as elimination half-life and total clearance of P and S in the present study were not appreciably different from those reported previously. The pharmacokinetic parameters of elimination half-life, total clearance and apparent volume of distribution of M were 11 days, 45.8 ml/h.kg, and 14.8 l/kg, respectively. Compared to previously published data on M in Thai patients, Caucasian, Brazilian and African subjects, it was found that the elimination half-life in Chinese subjects was similar to that in Thai patients, but different from Caucasian, Brazilian and African subjects. There were significant differences in total clearance and volume of distribution among Chinese subjects and Thai patients. The differences in pharmacokinetic behaviour of M between subject groups needs to be examined further. The relative bioavailability of P, S, and M in the lacquered and non-lacquered tablet formulations in the 6 subjects studied were not significantly different with values (mean +/- SD) of 0.98 +/- 0.06, 1.28 +/- 0.20 and 1.02 +/- 0.17, respectively.

[Comparative study of artemisinin suppositories and piperaquine phosphate in the treatment of falciparum malaria]

Artemisinin, developed by Chinese scientists, is a new type of anti-malarial drug with quick effect and low toxicity. Since its solubility in water or oil is very low, it cannot be made into a clear injection to be given intramuscularly or intravenously for emergency use. The artemisinin suppositories used in the study was provided by the institute of Chinese Materia Medica in 1982. Phase I and Phase II clinical trials of the drug were made by Guangzhou College of TCM. The results showed that the therapeutic effect of Artemisinin suppositories was satisfactory with no apparent side effects. The total dosage recommended was 2800-3200 mg. In 1986, fifty-six adults with falciparum malaria were treated with a total dose of 2800 mg Artemisinin suppositories for 3 days and randomly compared with a control group of Piperaquine phosphate in the Dongfang Town Hospital, Dongfang ( ) County of Hainan Island. The parasite clearance time in Artemisinin suppositories group (71.8 +/- 16.0 hrs) was significantly faster than that of Piperaquine phosphate group (100.3 +/- 20.3hrs), but recrudescence rate by 28 days (48.2%) was much higher than that of Piperaquine phosphate (17.0%). Artemisinin suppositories is simple to administrate and therefore it could be applied in endemic area of remote countryside and to the patients of incapable of oral dosing.

Double-blind dose finding study of mefloquine-sulfadoxine-pyrimethamine in children with acute falciparum malaria

Three different doses of a combination of mefloquine-sulfadoxine-pyrimethamine (MSP), given double-blind as a single dose to 60 children, were evaluated for efficacy and tolerance. The children, 42 boys and 18 girls aged between 5 and 15 years, received a mefloquine dose equivalent to 1, 1.5, or 2 standard MSP (Fansimef) tablets. Radical cure was obtained in all patients with only mild to moderate side effects of nausea and vomiting, which were not worse in the higher dose groups. For children living in an endemic malarious area, a single dose of mefloquine 7.1-12.5 mg/kg, given in combination with sulfadoxine (14.3-25.0 mg/kg) and pyrimethamine (0.7-1.3 mg/kg), is a safe and effective treatment for uncomplicated chloroquine-resistant Plasmodium falciparum malaria. This dose of MSP is approximately 10 mg/kg, 20 mg/kg and 1.0 mg/kg respectively of mefloquine, sulfadoxine and pyrimethamine, which is equivalent to a single standard tablet of Fansimef (mefloquine, 250 mg; sulfadoxine, 500 mg; pyrimethamine, 25 mg) given to a child weighing 20-30 kg.

Randomised comparative study of mefloquine, qinghaosu, and pyrimethamine-sulfadoxine in patients with falciparum malaria

A prospective trial in 80 patients randomly allocated to four antimalarial treatment regimens--mefloquine plus pyrimethamine-sulfadoxine ('Fansidar'); mefloquine plus qinghaosu; mefloquine, fansidar, and qinghaosu; and qinghaosu alone--was carried out on Hainan Island, China, in patients with chloroquine-resistant falciparum malaria. A radical cure with slight side-effects was obtained with mefloquine plus fansidar; the addition of qinghaosu greatly increased the rate of parasite clearance with no additional side-effects. Qinghaosu alone had a rapid rate of parasite clearance, no side-effects, but a high recrudescence rate. These antimalarial drugs seem to act at different stages of the asexual parasite cycle and their most efficient use may depend on when in the course of the disease they are given. Because of the continuing appearance of drug-resistant strains of Plasmodium falciparum combination drug therapy is now indicated, but which drugs and how best they should be used remains to be decided.