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Bacterial contamination of cotton as an indicator of respiratory effects among card room workers.

The influence of the bacterial contamination of cotton dust on the development of pulmonary symptoms has been investigated. The pulmonary function of card room workers in 23 US cotton mills was tested before and after the Monday working shift. A significant relation was found between the delta FEV1.0 decrement and the vertical elutriator dust level in the different mills. An improved correlation was obtained when the number of Gram-negative bacteria cultured from the bale cotton used in the different mills was employed in the exposure description. The results support earlier epidemiological and experimental studies, which demonstrate the importance of the Gram-negative bacteria in the development of pulmonary symptoms among workers in cotton mills.

Air Pollutants, Occupational↗

Interaction of atopy and exposure to cotton dust in the bronchoconstrictor response.

A survey of 255 workers in four cottonseed crushing mills included a respiratory health questionnaire, allergy skin testing, and measurements of lung function over the Monday working shift. Atopy was defined as having two or more positive weal reactions to common inhalant antigens. Categories of exposure to dust were based on the stage of milling, and one category contained workers with continuous exposure to cotton dust derived from linters, the cotton fibres adherent to cottonseed. Atopy and exposure to dust were found to have significant interaction: large mean declines in FEV1 and FEF 25-75 occurred only in the workers exposed to linter dust who were also atopic. Skin-testing surveys in cotton textile mills have concentrated on specific cotton antigen reactivity and its first-order relations to symptoms. Our results indicate a need to identify atopic workers, and to search for interactions between atopy and other variables that may influence acute changes in expiratory flow rates.

Adult↗

Airway constrictor response to cotton bract extracts in the absence of endotoxin.

Crude and purified aqueous extracts of cotton bracts shown to cause airway constriction in naive subjects were assayed for endotoxin content. Pulmonary function measured by flow changes on partial expiratory flow volume curves was used to assess airway responses to the bract extracts after their inhalation by a panel of volunteers. These responses are similar to the acute responses experienced by cotton textile workers. Crude aqueous extracts from various bracts harvested before and after senescence of the cotton plant displayed endotoxin concentrations ranging widely from 0.086 to 50 micrograms/ml. No correlation was found between these differences in endotoxin content and the severity of the airway constrictor response. Purifying the bract extract by a series of procedures that included precipitation of polymeric material by addition of methanol and chromatography on an anion exchange column of DEAE-Sephacel resulted in the elimination of almost all the endotoxin. The partially purified extract contained less than 1 ng/ml of endotoxin. The panel of volunteers responded to this purified bract extract, however, with a decrease in pulmonary function which was more than 60% of that seen with the crude extract of bracts. It is concluded that aqueous extracts of cotton bract contain an agent(s) other than endotoxin that causes acute airway constriction in people.

Adolescent↗

Mortality and disability among cotton mill workers.

The mortality and disability of cotton mill workers were studied in five Finnish cotton mills. The population under study comprised all 1065 women exposed to raw cotton dust who had been hired between 1950 and 1971. The minimum exposure period was five years. For the study on disability, the cohort was followed up until the end of 1981. The follow up period for the mortality analysis was from 1950 to 1985. At the end of 1981 the observed number of prevalent disability pensions for respiratory disease was 15, whereas 3.9 were expected (p less than 0.01) on the basis of the national figures for women. There were 46 musculoskeletal diseases (27.7 expected, p less than 0.01), of which 24 were osteoarthritis (14.5 expected) and 13 rheumatoid arthritis (6.6 expected). The incidence rates of disability pensions were calculated for the period 1969-81. Comparison of incidence rates between cotton mill workers and the Finnish female population showed excessive rates for both respiratory diseases (p less than 0.001) and musculoskeletal diseases (p less than 0.01), with an excess of new cases of rheumatoid arthritis (p less than 0.05). By the end of 1985 the number of person-years was 31,678 and the number of deaths 95. The standardised mortality ratios for the total period of follow up (1950-85) showed no excess for respiratory diseases. Mortality from cardiovascular diseases was also lower than expected. The observed number of tumours was 33, the corresponding expected number 32.0. Thirteen tumours were in the digestive organs (6.6 expected, p<0.05) and three were lung cancers (1.9 expected). Five workers had died from renal disease; the expected number was 1.5 (p<0.05).

Arthritis, Rheumatoid↗

The pineal body and pinealectomy in the cotton rat, Sigmodon hispidus.

The pineal body is known to be an important component in the regulation of seasonal reproduction. The gross morphology of the rodent pineal gland is highly variable and this variability may be related to the degree of its involvement in regulating reproduction. The size and complexity of the pineal gland of the cotton rat appear to be well correlated with the known reproductive responses of this species to photoperiod. The cotton rat pineal is a large (2,500 micrometer X 500 micrometer) mass originating from the dorsal diencephalon and extending dorsally to the superior sagittal sinus. The cotton rat pineal is solid and cannot be divided into deep and superficial portions as in some rodents. Animals obtained from the field were found to survive conventional pinealectomy when it was carried out under methoxyflurane anesthesia. These results indicate that the cotton rat could be used as a wild animal model for pineal gland-seasonal reproduction research.

Animals↗

Studies on the antigenic composition of aqueous cotton dust extracts.

An immune response to cotton dust components has been proposed as a possible mechanism of byssinosis. To evaluate this possibility, specific precipitating antibodies against aqueous cotton dust extracts (ACDE) were raised in rabbits, and a reference pattern for crossed immunoelectrophoresis (CIE) was established using this extract. A significant portion of the immune response was directed against Alternaria tenuis, Aspergillus niger, and Fusarium solani, all documented contaminants of cotton dust. Preliminary crossed radio-immunoelectrophoretic studies demonstrated that some of these antigens are allergenic in man, suggesting that an IgE-mediated hypersensitivity against cotton dust, or a fungal component of the dust, may be important in byssinosis pathogenesis.

Alternaria↗

Lung function, bronchial reactivity, atopic status, and dust exposure in Lancashire cotton mill operatives.

A total of 645 cotton mill operatives were administered a respiratory questionnaire. Of these, 85 (13.2%) complained of one or more work-related respiratory symptoms: 23 (3.6%) had byssinosis and the remaining 62 had symptoms not conforming to byssinosis (nonbyssinotic symptomatics, NBS). All byssinotic, 56 NBS, and 84 matched asymptomatic operatives underwent pulmonary function testing (FEV1 and FVC), skin testing to common allergens, and histamine bronchial challenge. Work area and personal breathing zone cotton dust concentrations were assessed, and a cumulative cotton dust exposure index was calculated for each individual. Byssinotic, NBS, and asymptomatic operatives all had reduced FEV1; observed mean liters (95% CI); predicted mean: byssinosis, 2.36 (2.09 to 2.63), 3.02; NBS, 2.94 (2.71 to 3.17), 3.29; and asymptomatic, 3.12 (2.95 to 3.29), 3.31. Only byssinotic subjects had evidence of impaired FVC: 3.31 (2.97 to 3.65), 3.69. The majority of byssinotic operatives (18 of 23) had bronchial hyperreactivity (BHR) in comparison with 21 of 56 NBS and 14 of 84 asymptomatic operatives. Mean log PD20 (95% CI) values were significantly lower in the byssinotic group -0.72 (-1.42, -0.02) than in NBS 0.57 (0.08, 1.06) and asymptomatic subjects 0.57 (-0.26, 1.39). The distribution of atopy did not differ significantly between groups, and lung function did not differ significantly between atopic and nonatopic subjects. The cumulative cotton dust exposure index was the only dust parameter to be significantly greater in those with BHR (mean mg-yr/m3 [95% CI] 14.13 [13.1 to 15.1]) than those with normal reactivity [5.35 (3.9 to 6.8)].

Adult↗

Bronchial reactivity, atopy, and airway response to cotton dust.

Studies of cotton textile workers have found an association between atopy and drop in FEV1 over a workshift. We studied the response of previously nonexposed volunteers with and without a history of mild atopy to a 5-h exposure to 1 mg/m3 of respirable cotton dust in a model cardroom. All participants were nonsmokers, had no history of asthma, and had normal spirometry. Twenty atopic subjects gave a personal history of mild respiratory allergy to pollen, dusts, or animals that had been confirmed by a physician. Thirty-two nonatopic subjects had no history of allergy. Spirometry and a methacholine challenge test were performed 1 to 2 days prior to exposure. Spirometry was repeated immediately before exposure to cotton dust; spirometry and a methacholine challenge were performed immediately after exposure. Atopic subjects showed a significantly higher mean serum IgE level to Phadiatop, a screening test to common inhalant allergens, than did nonatopic subjects (mean percent binding, 32.1 versus 1.5; p < 0.001). Atopic subjects had a significantly greater mean fall in FEV1 during exposure (8.3% versus 4.9%, p < 0.05). The difference in FEV1 decline between atopic and nonatopic subjects was similar in magnitude to that reported for workshift FEV1 declines between textile workers with and without mild atopy. Atopic subjects had significantly higher baseline methacholine responsiveness than did nonatopic subjects (26% versus 0% reaching a PD20, p < 0.0005). After cotton dust exposure, there was a significant increase in airway reactivity in both groups (68% versus 20% reaching a PD20, p < 0.0005). For all subjects combined baseline responsiveness was significantly related to the change in FEV1 after exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Chemotaxins in cotton mill dust: possible etiologic agent(s) in byssinosis.

Through the application of a simplified in vitro assay for chemotaxis of polymorphonuclear leukocytes, potent chemotaxins have been found to exist in cotton mill dust extracts. These substances may be involved in the recruitment of cells to pulmonary surfaces and in the etiology of byssinosis in textile workers who inhale cotton dust. The chemotaxins were extracted from cotton dust with alkaline aqueous solution and purified by chromatography on paper and Sephadex G-25. The active agents were readily water-soluble, stable to heat at 100 degrees C in water, inactivated by hydrolytic conditions, anionic, nonfluorescent, and had molecular weights of 200 to 2,000 daltons. Lacinilene, a fluorescent component of cotton dust reported by others to be chemotactic, was excluded by these properties and did not stimulate migration of leukocytes obtained from a variety of animal species. Pluronic polyol F68, a polypropylene glycol used as a dispersing agent, was found to represent a new class of chemokinetic substances and may account for earlier reports of chemotactic activity of lacinilene.

Animals↗

Cell-mediated cytotoxic responses in lungs of cotton rats infected with respiratory syncytial virus.

Pneumonia induced in cotton rats (Sigmodon hispidus) after inoculation of respiratory syncytial virus (RSV) was accompanied by the appearance of leukocytes in infected lungs. The number of these leukocytes increased until Day 5 after inoculation when sixfold more leukocytes were recovered from infected lungs using transpleural lavage than were recovered from lungs of uninfected control animals. Although macrophages and lymphocytes constituted approximately 65 and 25%, respectively, of the cells observed in lavage suspensions from both infected and uninfected lungs, only leukocytes in suspensions from infected animals appeared to be activated, as judged by cellular morphologic examination, cytochemical staining, and bactericidal activity. Leukocytes from lungs and adjacent lymph nodes of infected cotton rats, but not similar cells from uninfected animals, caused significant chromium release when they were added to primary cotton rat embryo and Hep-2 tissue culture cells infected with RSV in cytotoxicity assays. Cytotoxic activity peaked 5 days after inoculation, was neither virus-specific nor H-2 restricted, and was associated with both adherent and nonadherent fractions of lung cells. There was a close temporal relationship between the appearance of cytotoxic activity in the lung and termination of virus replication in this organ, suggesting a role for cytotoxic effector cells in recovery from respiratory syncytial virus infection of cotton rats.

Animals↗

Genetically modified cotton and farmers' health in China.

This study provides the first evidence of a direct link between the adoption of a genetically modified (GM) crop and improvements in human health. Estimation of the impact of Bacillus thuringiensis (Bt) cotton adoption on pesticide use from data from a survey of cotton farmers in northern China, 1999-2001, showed that Bt cotton adoption reduced pesticide use. Assessment of a health-production function showed that predicted pesticide use had a positive impact on poisoning incidence. Taken together, these results indicate that the adoption of Bt cotton can substantially reduce the risk and the incidence of poisonings.

Agriculture↗

Confirmation and quantification of strigolactones, germination stimulants for root parasitic plants Striga and Orobanche, produced by cotton.

The germination stimulants for root parasitic plants Striga and Orobanche produced by cotton (Gossypium hirsutum L.) were examined in detail. Seeds of cotton were germinated and grown on glass wool wetted with sterile distilled water in sterile filter units. The root exudate was collected daily and extracted with ethyl acetate. Each of these ethyl acetate extracts was analyzed directly by high-performance liquid chromatography linked with tandem mass spectrometry (LC/MS/MS). The results demonstrate that cotton roots exuded strigol and strigyl acetate, but no other known strigolactones such as orobanchol and alectrol. The production of strigol was detected even in the root exudate collected during the first 24 h of incubation and reached a maximum 5-7 days later. The average exudation of strigol and strigyl acetate during the incubation period was ca. 15 and 2 pg/plant/day, respectively, indicating that strigol mainly contributed to germination stimulation by the cotton root exudate.

Germination↗

The chemical composition of standard cotton dust.

Cotton dust samples from Cotton Incorporated were investigated by X-ray fluorescence and proximate analysis methods. These dust samples are known as "standard cotton dust" and have been used by many researchers investigating the causative agent(s) and physiological mechanisms of byssinosis. Silicon, calcium, potassium, and aluminum were present in relatively high concentrations (1-4%) in the dust fractions. The ash content of the dust fractions increased as the fraction particle size decreased. Proximate analyses demonstrate that "noncellulosic organics" are the major class of constituents (35-45%) in cotton dust. Cellulose comprises only 10-15% of the dust, while water-extractable materials comprise approximately 20% of the dust. Capillary gas chromatography performed on silylated, freeze-dried, aqueous extracts of the less than or equal to 38 micron dust fraction revealed the presence of phosphate, malate, arabitol, citrate, fructose, glucose, and mannitol.

Carbohydrates↗

Biologic activity of purified cotton bract extracts in man and guinea pig.

Purified aqueous extracts of cotton bract induce acute airway constriction in healthy volunteers never before exposed to cotton bract. The response is similar to that of textile workers who inhale cotton dust. Approximately 60% of volunteers respond to bract extract with significant decreases in lung function, and these volunteers show an increased number of lymphocytes present in their lungs. Following inhalation of bract, the percent of polymorphonuclear leukocytes increases. Macrophages obtained by bronchoalveolar lavage from volunteers pre-challenged with bract extract release increased amounts of chemotactic factor and superoxide anion. Efforts to detect release of histamine and leukotrienes in volunteers following challenge with bract show no increase in urinary histamine and no significant release of leukotrienes in lung lavage fluid. Purified extracts exhibit chemotactic activity in vitro. They also contract guinea pig ileal longitudinal muscle in vitro. This preparation contains mast cells but no basophils, and the H-1 blocker, mepyramine blocks the contraction. Purified bract extracts contain no histamine or endotoxin but other contractors of smooth muscle may be present. The purified extract exhibits spectral, fluorescent, and radioimmune assay properties similar to a leukotriene B-like component. Cotton bract appears to have direct as well as cell-mediated activities.

Adolescent↗

Functional analysis of a reproductive organ predominant expressing promoter in cotton plants.

Transgenic Bt insect-resistant cotton plants have high insect resistance in the early stage of development, but relatively low resistance in the late stage. Substituting a reproductive organ-specific promoter for the CaMV35S promoter presently being used could be an ideal solution. For the first time, the promoter sequence of ADP-ribosylation factor 1 (arf1) gene was isolated from Gossypium hirsutumY18 by means of inverse PCR. The sequencing result discovered the unique structure of the arf1 promoter, including four promoter-specific elements, the initiator, TATA box, CAAT box and GC box, and also an intron in 5'-untranslation region. Four plant expression vectors were constructed for functional analysis of the promoter. Based on the pBl121 plant expression vector, four truncated arf1 promoters took the place of the CaMV35S promoter. These vectors were different only in their promoter regions. They were introduced into cotton plants via pollen tube pathway. Histochemical GUS staining and fluorescence quantitative analyses were performed to examine the expression patterns of the GUS gene driven by the 4 arf1 truncated promoters in transgenic cotton plants respectively. The results showed that the arf1 promoter was a typical reproductive organ-specific promoter. Hopefully, the arf1 promoter can be a regulatory element for designing cotton reproductive organs with desired characteristics.

ADP-Ribosylation Factor 1↗

Some observations on epidemiologic studies in Egyptian gins, cotton pressing plants and cottonseed oil extraction plants.

The follow-up studies presented in this report wee conducted to evaluate the impact of the relative technical improvements that took place in the cotton processing industries of Egypt in the last 10-15 years on the health of the workers. Results have indicated tha: 1) the health status of the workers has been relatively improved; however, their work environment is far from being safe. 2) The prevalence of byssinosis and reduction in FEV1 during the first day of work after the weekend are related to the duration of exposure, level of dustiness and content of plant debris in dust. 3) Chronic effect of exposure to cotton dust, demonstrated as reduction in predicted FVC, develops in workers continuing exposure for long durations, even if the classic symptoms of byssinosis and reduction in FEV1 do not occur. 4) Women workers are more liable to be affected by cotton dust exposure than the men. 5) "Cottonseed dust" may not be a "byssinnogenic" dust; however, it is capable of producing ventilatory function effects similar to those produced by cotton dust.

Adolescent↗

Effect of selected insecticides on the natural enemies Coleomegilla maculata and Hippodamia convergens (Coleoptera: Coccinellidae), Geocoris punctipes (Hemiptera: Lygaeidae), and Bracon mellitor, Cardiochiles nigriceps, and Cotesia marginiventris (Hymenoptera: Braconidae) in cotton.

We evaluated the toxicity of three insecticides (lambda cyhalothrin, spinosad, and S-1812) to the natural enemies Bracon mellitor Say, Cardiochiles nigriceps Viereck, Coleomegilla maculata De Geer, Cotesia marginiventris (Cresson), Geocoris punctipes (Say), and Hippodamia convergens Guérin-Méneville, in topical, residual, and field assays. Lambda cyhalothrin exhibited the greatest toxicity to the natural enemies. In topical toxicity tests, lambda cyhalothrin adversely affected each natural enemy species studied. Residues of lambda cyhalothrin on cotton leaves were toxic to B. mellitor, C. nigriceps, C. maculata, and C. punctipes. Interestingly, residues of this insecticide were not very toxic to C. marginiventris and H. convergens. Geocoris punctipes and C. maculata numbers in the field generally were significantly lower for lambda cyhalothrin treatments than for the other four treatments, substantiating the previous tests. Although cotton aphids began to increase over all treatments around the middle of the test period, the number of cotton aphids in the lambda cyhalothrin plots was significantly higher than the number in any of the other treatments. As cotton aphids increased in lambda cyhalothrin field plots, the predator H. convergens also increased in number, indicating that lambda cyhalothrin did not adversely affect it in accordance with the residual tests. Spinosad exhibited marginal to excellent selectivity, but was highly toxic to each parasitoid species and G. punctipes in topical toxicity tests and to B. mellitor in residual tests. Spinosad generally did not affect the number of G. punctipes, H. convergens, and C. maculata in the field except for one day after the second application for G. punctipes. S-1812 exhibited good to excellent selectivity to the natural enemies. Some reduction of G. punctipes occurred for only a short period after the first and second application of this insecticide in the field. H. convergens and C. maculata were affected very little by S-1812.

Animals↗

Precision application of aldicarb to enhance efficiency of thrips (Thysanoptera: Thripidae) management in cotton.

Field studies were conducted during 1999-2001 in two climatic/edaphic areas of Georgia (Southern Piedmont and East Gulf Coastal Plain) to test the hypothesis that precision placement of aldicarb with cotton seed in hill planting at spatially specific intervals could decrease insecticide use for management of tobacco thrips, Frankliniella fusca (Hinds). Precision-placed aldicarb controlled thrips during cotton seedling stages using per ha amounts of one-half or less than standard in-furrow application rates with no significant differences in yield. Residual analysis of cotton plants showed that plants in precision placement plots had as much or more aldicarb and aldicarb metabolites present as compared with cotton treated with conventional in-furrow treatments. Higher rates of precision-placed aldicarb did cause phytotoxic burning early in the growing season, but no significant impact on yield was observed.

Aldicarb↗