[Effect of Suanzaoren Decoction on expression of ionotropic glutamate receptors and synaptic plasticity in hippocampus of anxiety rats]

This study investigated the effect of Suanzaoren Decoction on the expression of N-methyl-D-aspartate receptors(NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors(AMPAR) in the hippocampus and synaptic plasticity in rats with conditioned fear-induced anxiety. The effect of Suanzaoren Decoction on rat behaviors were evaluated through open field experiment, elevated plus maze experiment, and light/dark box experiment. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of glutamate(Glu) and γ-aminobutyric acid(GABA) in the rat hippocampus. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to assess the gene and protein expression of ionotropic glutamate receptors in the hippocampal region. Transmission electron microscopy was utilized to observe the changes in the ultrastructure of synaptic neurons in the hippocampal region. Long-term potentiation(LTP) detection technique was employed to record the changes in population spike(PS) amplitude in the hippocampal region of mice in each group. The behavioral results showed that compared with the model group, the Suanzaoren Decoction group effectively increased the number of entries into open arms, time spent in open arms, percentage of time spent in open arms out of total movement time, number of entries into open arms out of total entries into both arms(P<0.01), and significantly increased the time spent in the light box and the number of shuttle crossings(P<0.01). There was an increasing trend in the number of grid crossings, entries into the center grid, and time spent in the center grid, indicating a significant anxiolytic effect. ELISA results showed that compared with the model group, the Suanzaoren Decoction group exhibited significantly reduced levels of Glu, Glu/GABA ratio(P<0.01), and significantly increased levels of GABA(P<0.01) in the rat hippocampus. Furthermore, Suanzaoren Decoction significantly decreased the gene and protein expression of NMDAR(GluN2B and GluN2A) and AMPAR(GluA1 and GluA2) compared with the model group. Transmission electron microscopy results demonstrated improvements in synapses, neuronal cells, and organelles in the hippocampal region of the Suanzaoren Decoction group compared with the model group. LTP detection results showed a significant increase in the PS amplitude changes in the hippocampal region of Suanzaoren Decoction group from 5 to 35 min compared with the model group(P<0.05, P<0.01). In conclusion, Suanzaoren Decoction exhibits significant anxiolytic effects, which may be attributed to the reduction in NMDAR and AMPAR expression levels and the improvement of synaptic plasticity.

Ligature-Induced Periodontitis Drives Colorectal Cancer: An Experimental Model in Mice

Periodontitis is a prevalent inflammatory oral disease associated with an increased risk of colorectal cancer. Experimental animal models are critical tools to investigate the effects and mechanisms of periodontitis on colorectal cancer. Several murine periodontitis models have been used in research, including oral gavage, periodontal pathogen injection, and ligature models. The role of experimental periodontitis caused by silk ligation in colorectal cancer remains unclear. In this study, we used an experimental periodontitis model on a colitis-associated colorectal cancer model and a spontaneous model, respectively. We observed the promotion of colorectal cancer in ligature-induced periodontitis mice compared to those control mice in 2 different models, as assessed by tumor number, tumor size, and tumor load. Since bacterial dysbiosis is an important feature of periodontitis, we next analyzed the oral and gut microbiomes using 16S ribosomal RNA gene sequencing. We found that the experimental periodontitis model reshaped the microbial community in the oral cavity and gut. In addition, we found a higher extent of programmed death 1 (PD-1)-positive CD8⁺ T-cell infiltration in tumor samples of the periodontitis group than in controls by immunofluorescence staining. Regarding the potential molecular mechanism, we transplanted the fecal microbiota of the periodontitis patient into mice and observed a tumor-promoting effect in the periodontitis group, assessed by tumor volume and tumor weight, together with a low level of INF-γ⁺ CD8⁺ T-cell infiltration in subcutaneous tumor mice. Taken together, we show that ligature-induced periodontitis model promotes colorectal cancer by microbiota remodeling and suppression of the immune response.

Full length transcriptomes analysis of cold-resistance of Apis cerana in Changbai Mountain during overwintering period

Apis cerana in Changbai Mountain is an ecological type of Apis cerana, which is an excellent breeding material with cold-resistant developed by long-term natural selection under the ecological conditions. However, the physiological and molecular mechanisms of Changbai Mountain population under cold stress are still unclear. In this study, the Nanopore sequencing was carried out for the transcriptome of Apis cerana in Changbai Mountain in the coldest period of overwintering, which will provide a reference to the cold-resistant mechanism. We determined 5,941 complete ORF sequences, 1,193 lncRNAs, 619 TFs, 10,866 SSRs and functional annotations of 11,599 new transcripts. Our results showed that the myosin family and the C2H2 zinc finger protein transcription factor family possibly have significant impacts on the response mechanism of cold stress during overwintering. In addition, the cold environment alters genes expression profiles in honeybees via different AS and APA mechanisms. These altered genes in Hippo, Foxo, and MARK pathways help them counter the stress of cold in overwinter period. Our results might provide clues about the response of eastern honeybees to extreme cold, and reflect the possible genetic basis of physiological changes.

[An acute schistosomiasis case in Wuhan City imported from another province of China in 2020]

An imported case of acute schistosomiasis was reported in Wuhan City in 2020. The case was infected with Schistosoma by contact with the infested water due to playing water in the Yangtze River when working out of Hubei Province. The patient visited four medical institutions and the duration from onset to definitive diagnosis was 20 days. The patient's low awareness of schistosomiasis prevention and control knowledge and lack of diagnosis and treatment awareness for schistosomiasis among medical institutions were considered as main causes of the development of acute schistosomiasis and progression to severe case. Intensifying schistosomiasis health education among mobile populations and improving the awareness and capability of early diagnosis of schistosomiasis among clinicians are recommended.

The complete chloroplast genome sequence of Artocarpus hypargyreus

The complete chloroplast genome sequences of Artocarpus hypargyreus was reported in this study. The length of the sequence was 160,952 bp in length with a large single copy (LSC) region of 89,476 bp, the small single copy (SSC) region of 20,070 bp and two inverted repeat (IR) regions of 25,703 bp. The complete genome contains 129 genes including 84 protein-coding genes, 8 rRNA genes and 37 tRNA genes. Phylogenetic analysis of the Moraceae based on 8 plastome sequence shows that A. hypargyreus is most related to Morus cathayana.

[Diagnostic and epidemiological features of the first two HIV-2 indigenous infections in Hunan province]

Objective: To study the diagnostic and epidemiological features of the first two HIV-2 indigenous cases in Hunan province. Methods: Blood samples from two individuals with "HIV antibody indeterminate" and HIV-2 specific band showed by HIV-1/2 western blotting method, were repeatedly collected and detected under HIV 1+2 strip immunoassay and PCR, in Changsha city, Hunan province, through March to November, 2017. An epidemiological survey was carried out at the same time. Results: Our findings showed that the two cases were sex partners, without histories of sexual contact with foreigners and the source of infection was unknown. Results from the HIV 1+2 antibody confirmation test showed that they were "HIV-2 antibody positive" . Through amplifying and sequencing the gag area of HIV-2 and BLAST, the similarity of HIV-2 strains presented as 98%. The results also showed that there were HIV-2 specific fragments in the two cases. Conclusion: HIV-2 indigenous cases had never been reported in China. These cases had brought new challenge on prevention, diagnosis and treatment of HIV/AIDS in China.

[Survey of the depressive disorders prevalence and related risk factors among male new drug users in certain drug rehabilitation center of Changsha city]

Objective: To understand the depressive disorders prevalence and related risk factors among new drug users in a male drug rehabilitation center. Methods: The cross-sectional study was used. A total of 250 new drug users from a male drug rehabilitation center were recruited during March, 2017. The drug users who only use new type of drugs single or use traditional drugs at the same time were collected as the new drug users. Their general information and drug-related information were collected by self-made questionnaire, and depressive disorders and sleep quality information were collected by the self-reported Patient Health Questionnaire-9 (PHQ-9) and the self-reported Pittsburgh Sleep Quality Index Questionnaire respectively. Logistic regression test was used to establish associations between variables. Results: Of all 250 drug users, the mean age (P(25), P(75)) was 30 (26, 35) years old, and 32.8% (82) had the depressive disorders. The individuals taking drug dose over 0.4 g daily before entering drug rehabilitation center had significantly more risk of the depressive disorders for 3.18 (1.71-5.90) than those not over 0.4 g daily.The individuals who bad sleep quality had significantly more risk of the depressive disorders for 6.07 (95%CI:3.31-11.12) than those had good sleep quality.The individuals who were depressive patients before the first drug use for 2.39 (95%CI: 1.12-5.10) than those were not depressive patients before the first drug use. Conclusion: There were a high rate of the depressive disorders among new drug users in the rehabilitation center; In addition, several risk factors including the individuals taking drug dose over 0.4 g daily and bad sleep quality, history of the depressive disorders were negatively associated with depressive disorders.

[The influence of chemotherapy-induced leucopenia on the disease-free survival of gastric cancer patients after radical gastrectomy]

Objective: To investigate the association between chemotherapy-induced leucopenia and patients' disease-free survival in gastric cancer patients who received radical gastrectomy. Methods: The clinical data of 273 gastric cancer patients who received radical gastrectomy and postoperative adjuvant chemotherapy between January, 2010 and December, 2015 in PLA 309(th) hospital was reviewed retrospectively. Results: A total of 195 (71.4%) patients experienced at least one time of leucopenia, while it was absent in the other 78 (28.6%) patients. The median disease-free survival of patients with or without leucopenia was 49.7 and 44.0 months respectively (P=0.009), leucopenia was an independent factor influencing patients' disease-free survival (HR=2.758, P=0.022), but there was no statistical difference between the disease-free survival of patients with different degrees and frequency of leucopenia (P=0.446, 0.123). Conclusion: Chemotherapy-induced leucopenia is a predictor of good prognosis for gastric cancer patients who receive radical gastrectomy.

[Effects of continuous positive airway pressure on periodic limb movements during sleep in patients with obstructive sleep apnea]

Objective: To investigate the effects of continuous positive airway pressure (CPAP) on periodic limb movements during sleep (PLMS) in patients with obstructive sleep apnea (OSA). Methods: The polysomnography (PSG) data of 828 consecutive OSA outpatients from January 2015 to January 2017 who had undergone overnight CPAP titration were analyzed retrospectively. On the basis of changes in periodic limb movements index (PLMI) values (cut off level≥15/h) from baseline PSG (BPSG) to CPAP titration PSG, patients were assigned to one of the following four groups: persistent, CPAP-emergent, CPAP-disappeared, and non-PLMS. Results: Among 828 patients, 756 (91.3%) were male and 72 (8.7%) were female. The mean age was (45.7±10.7) years old, the mean body mass index (BMI) was (27.6±3.5) kg/m(2). The rate of patients was 3.9% in the persistent group, 10.3% in the CPAP-emergent group, 7.5% in the CPAP-disappearance group, and 78.4% in the non-PLMS group. Multivariate Logistic regression analysis revealed that female appeared to be associated with the persistent group (P=0.004); older age and higher apnea-hypopnea index (AHI) on BPSG appeared to be associated with the CPAP-emergent group (P=0.012, 0.030). On the other hand, older age was negatively associated with the non-PLMS group (P=0.006). Conclusion: Elderly patients with higher AHI at BPSG may present with CPAP-emergent PLMS.

[Gender differences of REM related obstructive sleep apnea-hypopnea syndrome]

Objective: To explore the gender differences of rapid-eye-movement (REM) related obstructive sleep apnea-hypopnea syndrome (OSAHS). Methods: Consecutive patients with primary complaint of snoring from Sleep Medicine Center of West China Hospital between January 2016 and November 2016 were included in the study. All participants underwent one night polysomnography (PSG) and Epworth sleep scale (ESS) was estimated. The patients diagnosed with OSAHS were classified as REM related OSAHS (REM-OSAHS group) and non-rapid-eye-movement (NREM) related OSAHS (NREM-OSAHS group) based on the PSG parameters. And the gender differences of demographic and polysomnograpic characteristics in both groups were compared. The associations between apnea-hypopnea index (AHI) and body mass index (BMI), neck circumference and waist circumference among patients with OSAHS were explored by multiple linear regression analysis. Results: A total of 1 258 patients were diagnosed with OSAHS. There were 997 (79.3%) male and 261 (20.7%) female among these patients, the mean age was (46.4±12.0) years old and mean BMI was (26.6±3.4) kg/m(2). There were 236 patients (18.8%) classified into REM-OSAHS group, and 1 022 patients (81.2%) classified into NREM-OSAHS group; the proportion of REM-OSAHS in female was significantly higher than that in male (34.1% vs 14.7%, P<0.001). After controlling for age, drinking, smoking, hypnotics, coffee, strong tea and sleep related parameters, in NREM-OSAHS group, AHI was positively correlated with BMI, neck circumference and waist circumference (P<0.001) both in male and female. In REM-OSAHS group, AHI was positively correlated with BMI, neck circumference and waist circumference in female (P<0.05), but only significantly correlated with BMI and waist circumference in male (P<0.05). Conclusions: REM-OSAHS is commonly seen in female OSAHS patients. Evaluation of the influences of anthropometric data on the severity of REM-OSAHS should consider the impact of gender.

Association between dietary intake of folate and MTHFR and MTR genotype with risk of breast cancer

We investigated the association between dietary intake of folate, vitamin B6, and the 5,10-methylenetetrahydrofolate reductase (MTHFR) genotype with breast cancer. A matched case-control study was conducted, and 413 patients with newly diagnosed and histologically confirmed breast cancer and 436 controls were recruited. Folate intake, vitamin B6, and vitamin B12 levels were calculated, and the MTHFR C677T and A1298C and MTR A2756G polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Breast cancer cases were generally older, older at first live birth, and younger at menarche, had a higher body mass index, were smokers, had higher energy intake, and more first-degree relatives with breast cancer as well as more live births compared to controls. With respect to energy intake, we found that higher energy intake were more likely to increase the risk of breast cancer. The MTHFR 667TT genotype was associated with a moderately increased risk of breast cancer when compared with the CC genotype, and a significant odds ratio (OR; 95% confidence interval, CI) was found (OR = 1.70, 95%CI = 1.06-2.73). Individuals carrying T allele were associated with higher risk of breast cancer when compared with C allele (OR = 1.34, 95%CI = 1.06-1.70). We did not find a significant effect of the MTHFR A1298C and MTR A2756G on the risk of breast cancer. We did not find any association between folate intake and MTHFR C677T polymorphisms. In conclusion, we found that the MTHFR C667T polymorphism is associated with the risk of breast cancer, indicating that this genotype plays a role in breast cancer development.

Neural activity in relation to temporal distance: differences in past and future temporal discounting

This study investigated the differences between past and future temporal discounting in terms of neural activity in relation to temporal distance. Results show that brain regions are engaged differently in past and future temporal discounting. This is likely because past temporal discounting requires memory reconstruction, whereas future temporal discounting requires the processing of uncertainty about the future. In past temporal discounting, neural activity differed only when preferences were made between rewards received one hour prior and rewards received further in the past. The peak amplitudes of P2 and P3 varied as the temporal distance increased from 2 weeks to 50 years. In future temporal discounting, neural activity differed only when preferences were evaluated between two delayed rewards. The delay conditions (6 months:5 years) and (6 months:50 years) had a significant influence on P2 and N2. Findings indicate the existence of different decision-making systems operating in past and future temporal discounting.

Is GPR39 the natural receptor of obestatin?

GPR39, an orphan receptor belonging to the family of G protein-coupled receptors, was originally reported to be the receptor of obestatin. However recently, numerous reports have questioned this conclusion. In mammals, GPR39 was reported to be involved in the regulation of gastrointestinal and the metabolic functions. In this article, a latest and brief review on the receptor family, structure, distribution and physiological functions of GPR39 has been reported.

Effect of phytase supplementation to a low- and a high-phytate diet for growing pigs on the digestibilities of crude protein, amino acids, and energy1,2,3

Supplementation of microbial phytase usually improves the digestibility and utilization of phosphorus in feedstuffs of plant origin. The effect of phytase supplementation on the digestibilities of AA also has been examined, but the results have been inconsistent. This study was carried out to determine the effect of phytase (Natuphos) supplementation, at a rate of 2,000 phytase units/kg, to two basal diets on the apparent ileal digestibilities (AID) of GE, CP, and AA, and on the apparent total-tract digestibilities (ATTD) of CP and GE. The basal diets contained 18% CP and were formulated (as-fed basis) to contain either a low (0.22%) or high content (0.48%) of phytate P. The high-phytate diet contained 20% rice bran, which is a rich source of phytate and has low intrinsic phytase activity. Eight barrows (average initial BW = 40.6 kg), fitted with a simple T-cannula at the distal ileum, were fed the four diets according to a replicated 4 x 4 Latin square design. The pigs were fed twice daily at 0800 and 2000, equal amounts each meal, at a rate of 2.4 times the daily maintenance requirement for ME. Each experimental period comprised 14 d. Ileal digesta were collected from 0800 to 2000 on d 12, 13, and 14. Feces were collected from 0800 on d 8 until 0800 on d 12. Chromic oxide was used as the digestibility marker. The AID of GE, CP, and AA and the ATTD of CP and GE were less in the high- than in the low-phytate diet (P < 0.01). With the exception of glutamic acid, phytase supplementation did not affect (P > 0.10) the AID of CP and AA. There was no effect (P > 0.05) of phytase on the ATTD of CP and GE. These results show that if a response occurs to phytase supplementation, it is independent of the dietary phytate content.

Effect of phytase supplementation to diets for weanling pigs on the digestibilities of crude protein, amino acids, and energy1,2,3

Four experiments were conducted with weanling pigs fitted with a simple T-cannula at the distal ileum, to determine the effect of phytase supplementation to four diets on the apparent ileal digestibilities (AID) of CP and AA, and the apparent total-tract digestibilities (ATTD) of CP and DE. Phytase (Natuphos, DSM Food Specialties, Delft, The Netherlands) was supplemented at rates of 0, 500 or 1,000 FTU/kg to the four diets. A 20% CP (as-fed basis) corn-soybean meal diet was used in Exp. 1; a 20% CP wheat-soybean meal diet in Exp. 2; a 20% CP wheat-soybean meal-canola meal diet in Exp. 3; and a 19% CP barley-peas-canola meal diet in Exp. 4. In each experiment, six barrows, fitted with a simple T-cannula at the distal ileum, were fed the basal plus phytase-supplemented diets according to a repeated 3 x 3 Latin square design. Each experimental period comprised 14 d. The piglets were at fed 0800 and 2000 daily, equal amounts for each meal, at a daily rate of at least 2.4 times the maintenance requirement for ME. Feces were collected from 0800 on d 8 until 0800 on d 12 of each experimental period. Ileal digesta were collected from 0800 to 2000 on d 12, 13, and 14. Chromic oxide was used as the digestibility marker. The average initial and final BW (average of all experiments) were 7.9 and 16.5 kg, respectively. Phytase supplementation did not improve the AID of CP and AA in Exp. 1, 2, and 4; however, there were improvements (P < 0.05) or tendencies (P < 0.10) toward improvements in the AID of CP and AA or the ATTD of CP and the content of DE with phytase supplementation in Exp. 3. These results suggest that the AA response factor to microbial phytase supplementation depends on diet composition.

Concentration-time exposure index for modeling soil fumigation under various management scenarios

Best management decisions in soil fumigation require informed management selections of soil type, field geometry, application dosage, and depth to maximize fumigant distribution for efficacy and minimize off-site transport for environmental safety. An efficacy- or exposure-based concentration-time exposure index (CTEI) was used to serve as a continuous quantitative efficacy assessment for soil fumigation by subsurface drip irrigation using numerical model simulations. The CTEI was defined as the ratio between the soil volume where concentration-time (CT) exceeded a threshold value for a particular pest-fumigant combination and the total soil volume required for fumigation treatment. Applications of CTEI as a simple efficacy index were demonstrated by simulating combinations of three soil types (loam, sandy loam, sand); three field configurations consisting of 102- and 203-cm-wide bed systems and a flat surface system; three application depths (15, 30, 45 cm); and two application rates (82 and 327 kg ha(-1)) for 1,3-dichloropropene against citrus nematode (Tylenchulus semipenetrans) using a threshold air-phase CT value of 12 microg h cm(-3) obtained from a separate field study. For soil fumigation by subsurface drip irrigation, the order of importance in optimizing CTEI was soil type, depth of application and depth of treatment, dosage, and field configuration. Model simulation using CTEI as a numeric efficacy index can be an effective alternative to assist in the planning of field trials for making final management decisions concerning soil fumigation or other pesticide applications.

Smoking and mortality in 81,344 drivers in Guangzhou, China

OBJECTIVES

Previous studies on drivers focused on the effect of their exposure to vehicle exhaust and there is little evidence of the effect of smoking. This cohort analytical study aimed to examine the mortality of drivers relative to smoking and professional driving in Guangzhou, China.

METHODS

Information on demographic characteristics, type of driver (professional and non-professional), smoking, and drinking were retrieved from medical records of drivers who applied for driving licences from March to December 1992. Vital status and causes of death of 81,344 men aged 30 or above were ascertained to the end of September 1999 (follow up, mean=7.14 years, median=7.17 years).

RESULTS

At baseline, the mean (SD) age was 40.8 (5.6) years. One third were professional drivers; 49.0% were daily smokers. 858 Deaths were identified. The relative risk of overall mortality for ever smoking was 1.24 (95% confidence interval (95% CI) 1.07 to 1.44) after adjusting for age, alcohol drinking, education, and type of drivers. Compared with non-professional drivers, professional drivers had similar risks of death, and their relative risk of overall mortality for ever smoking was 1.35 (1.06 to 1.71).

CONCLUSIONS

Smoking is a more important cause of death than professional driving itself. The results show serious public health problems in the early stage of the tobacco epidemic and support urgent measures to help drivers stop smoking.

Delta-aminolevulinate dehydratase polymorphism and blood lead levels in Chinese children

This study investigated the relationship between the delta-aminolevulinate dehydratase (ALAD) isozymes and the blood lead levels of Chinese children. The purpose of this study was to determine the precise ALAD genotyping in Chinese children and identify the contribution of the ALAD genotype to the body lead burden. Blood samples were obtained from 109 boys and 120 girls. These children were 6-10 years old and from a single primary school. Both the school and their homes were within a community in which a large smelter was located. An environmental questionnaire was obtained for each subject, and blood lead levels and ALAD isozyme phenotype were analyzed in a double-blinded fashion. The blood lead levels of 229 children ranged from 4.5 to 26.4 microg/dl; the mean was 10.3 microg/dl and the standard deviation was 3.3 microg/dl. The gene distribution of the ALAD isozyme phenotypes in these environmentally exposed children was ALAD 1-1 (92%), ALAD 1-2, (8%), and ALAD 2-2 (0%). The mean blood level of the environmentally exposed children, who were homozygous for the ALAD1 allele, was 9.7 microg/dl; the mean for those who were heterozygous for the ALAD2 allele was 11.7 microg/dl. Using the t test, the means of the groups were different at the level of t=2.2058, P<0.05. Step-wise regression and multiple analyses of covariance were employed to control the confounders to measuring the independent contribution of the ALAD genotype on blood lead levels. After controlling the confounders, the contribution of the ALAD genotype to the blood lead level was greater and still statistically significant (F=7.3201, P<0.01). These results indicate that individuals carrying the ALAD2 allele are more likely to have sustained increases in blood lead levels when exposed to a lead-contaminated environment.

Smoking and exposure to occupational hazards in 8,304 workers in Guangzhou, China

This cross-sectional study aimed to describe the pattern of smoking in relation to occupational hazard exposure in a working population in Guangzhou, China. In 1994, data on smoking and occupational hazard exposure from occupational health records of 8,304 subjects aged 35 years or older from 47 randomly selected factories were studied. About 49% of the men and 55% of the women were exposed to dust, chemicals or other hazards. The prevalence of smoking was 56.1% in men and 2.0% in women. The prevalence of smoking in men was higher in those who were younger, with primary education or who were workers. In women, those who were older, with primary education or in management jobs had higher smoking prevalence. In men and women, subjects who were exposed to occupational hazards had higher smoking prevalence: the highest (71.6%) was found in male workers exposed to dust. Urgent tobacco control measures are needed to prevent the epidemic of smoking-related and occupation-related diseases in the workplace in China.

Byssinosis in Guangzhou, China

OBJECTIVES

To study the prevalence of byssinosis and other respiratory abnormalities in workers exposed to cotton dust in Guangzhou in two factories that processed purely cotton.

METHODS

All the 1320 workers exposed were included. The controls were 1306 workers with no history of occupational dust exposure. Total dust and inhalable dust were measured by Chinese total dust sampler and American vertical elutriator respectively. A World Health Organisation questionnaire was used. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured by a Vitalograph spirometer.

RESULTS

The median inhalable dust concentrations ranged from 0.41 to 1.51 mg/m3 and median total dust concentrations from 3.04 to 12.32 mg/m3. The prevalence of respiratory abnormalities in the cotton workers were (a) typical Monday symptoms 9.0%; (b) FEV1 fall by > or = 5% after a shift 16.8%; (c) FEV1 fall by > or = 10% after a shift 4.2%; (d) FEV1 < 80% predicted 6.1%; (e) FEV1/FVC < 75% 4.0%; (f) cough or phlegm 18.2%; (g) chronic bronchitis 10.9%; and (h) byssinosis, defined by (a) plus (b) 1.7%. With the exception of (d), most of the prevalences increased with increasing age, duration of exposure, and cumulative inhalable dust exposure. No increasing trends of respiratory abnormalities were found for current total dust, inhalable dust, and cumulative total dust concentrations. Compared with controls, after adjustment for sex and smoking, with the exception of (d), all the pooled relative risks of respiratory abnormalities were raised for cotton exposure.

CONCLUSION

It is concluded that cumulative inhalable cotton is likely to be the cause of byssinotic symptoms, acute lung function decrements, cough, or phlegm, and chronic bronchitis.