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Acute lung function response to cotton dust in atopic and non-atopic individuals.

Acute spirometric responses to inhaled cotton dust were examined in a population of 226 healthy, non-asthmatic adults whose atopic status had been evaluated by skin prick tests to 10 common environmental allergens. Exposure to cotton dust occurred in model cardrooms where elutriated dust levels were carefully controlled (1.02 mg/m3). Atopy, defined as positive prick tests to at least two allergens, was observed in 26% of subjects. Significant forced expiratory volume in one second (FEV1) decrements occurred after exposure to cotton dust independent of atopic status (p less than 0.001). The mean FEV1 decline in atopic subjects, however, was significantly greater than in non-atopic subjects (p less than 0.05). Degree of atopy, as measured by number of positive skin tests, also exhibited a significant association with cotton induced decrements in FEV1 (p less than 0.05). These data suggest that atopy may be an important determinant of the magnitude of the acute pulmonary response to cotton dust. This may reflect the non-specific airways hyperresponsiveness that has been described in non-asthmatic, atopic individuals.

Adult↗

Effect of alkali treatment on physiological activity of cotton condensed tannin.

Cotton dusts contain condensed tannins and endotoxins, which are suspected of contributing to the development of acute and chronic biological responses in some cotton textile mill workers. Condensed tannin extracted from cotton dust was coated on to cellulose powder, and the tannin coated powder was treated with an alkali solvent system previously developed to reduce the endotoxin content and pulmonary toxicity of cotton dust. Physiological activities of the dusts and powders were compared by assaying the production of the arachidonic acid metabolites prostaglandin F2 alpha (PGF2 alpha), thromboxane A2 (TxA2) (the precursor to thromboxane B2 (TxB2], leukotriene C4 (LTC4), and prostaglandin E2 (PGE2) by guinea pig pulmonary cells obtained by lung lavage. Cotton dust stimulated the pulmonary cells to produce a total of 29 pg metabolites per 10(6) cells. Production of metabolites by cells stimulated with tannin coated cellulose powder was reduced to 8.3 pg/10(6) cells. Alkali treatment of the tannin coated cellulose powder resulted in a further decrease in its ability to stimulate the cells, producing 3.5 pg metabolites per 10(6) cells. The ability of the dusts and powders to stimulate production of metabolites of arachidonic acid by pulmonary cells from guinea pigs was highly correlated with tannin content of the materials, but not with endotoxin content as measured by the Limulus amoebocyte lysate (LAL) assay.

Animals↗

Biophysical alteration of lung surfactant by extracts of cotton dust.

Byssinosis, a lung disease that can affect cotton mill workers, may be caused in part by lipopolysaccharides (LPS) from Gram negative bacteria. In vitro, LPS complexes with sheep lung surfactant (SLS). To determine whether LPS in extracts of cotton dust alters the biophysical characteristics of lung surfactant, aqueous extracts (1.0% w:v) of sterile surgical cotton (SSC) and a bulk raw cotton dust (1182DB) were prepared. Aliquots of the soluble extracts were incubated with SLS and studied by sucrose gradient centrifugation, surface tension analysis, and high pressure liquid chromatography (HPLC). The chromatography was employed to analyse for 3-hydroxymyristate (3-HM), a fatty acid indicating LPS. Also, purified Enterobacter agglomerans LPS and 3-HM as controls and as mixtures with SLS, were studied by HPLC. Sucrose gradient centrifugation showed that SLS-SSC, SLS-1182DB, and the SLS control had similar densities that differed from the remaining controls. The SLS-1182DB exhibited a floccule absent in the other samples. Surface tension values of SLS-SSC and SLS-1182DB differed significantly from all controls but only slightly from one another. 3-Hydroxymyristate was detected by HPLC in the 3-HM control, EA-LPS, SLS-EA-LPS, and SLS-1182DB, but not in SLS-SSC or the remaining controls. Apparently, 3-HM was below the HPLC detection range in SSC. The data indicate that LPS in the 1182DB, SSC and EA-LPS samples complexed with SLS. Floccule development in SLS-1182DB but not in SLS-EA-LPS suggests a further component(s) present in the bulk raw cotton dust, as well as LPS, which complexes with SLS. The data suggest that biophysical alterations to lung surfactant may play a part in the pathogenesis of byssinosis.

Animals↗

Longitudinal study of the health of cotton workers.

OBJECTIVES: To follow up a group of newly employed workers in a cotton mill, and to report changes in symptoms over time. METHODS: A group of 110 mill workers at a cotton mill in Shijiazhuang, China, was investigated by questionnaire, skin testing, and spirometric measurements of airway responsiveness through forced expiratory volume in one second (FEV1). The workers were examined before starting work, at 10 weeks, and at one year. RESULTS: Decreases in FEV1 over shifts were small at 10 weeks and one year, and slightly higher among people with skin reactions to cotton dust extracts. Airway responsiveness, defined as the average decrease in FEV1 after 1.25 mg methacholine was increased at 10 weeks. It remained about the same after one year, except in the workers positive for the skin test, in whom it was further increased. Subjective symptoms of chest tightness and cough with phlegm increased progressively at 10 weeks and one year; nasal irritation remained unchanged and dry cough decreased between 10 weeks and one year. CONCLUSION: The results suggest that the airway inflammation caused by cotton dust increases with increasing exposure time and that the changes are more notable in workers with reactivity to cotton dust extract.

Adolescent↗

Prevalence of byssinosis and respiratory symptoms among cotton mill workers.

BACKGROUND: While the prevalence of byssinosis is decreasing in industrialized countries and persists at high levels in developing countries, this prevalence is remaining constant in Turkey. OBJECTIVE: In order to determine the effects of past cotton dust exposure on the respiratory tract, a total of 223 persons working in a cotton mill were included in this study. METHODS: A questionnaire was used to inquire about respiratory symptoms. Participants underwent several spirometric measurements, which were performed on the 1st, 3rd and 5th day of the working week. Cotton dust measurements were performed in different divisions of the factory. RESULTS: The most common respiratory symptom was chest tightness (20.3%). The prevalence of byssinosis was 14.2% in cotton-processing workers. Among these cases, 28.6% had symptoms on the 1st day of the week, and 71.4% had symptoms on all days of the week. An acute effect was seen in 53.6% of the workers with byssinosis. Mean respirable dust levels were between 0.095 and 0.413 mg/m(3). CONCLUSIONS: In spite of technological improvements, respirable dust concentrations are still above the permissible limits, and thus the risk of byssinosis remains. Workers in the cotton industry where obsolete technology is used and standardized protection measures are not applied should be followed for byssinosis.

Adult↗

Nasal antibodies against gram-negative bacteria in cotton-mill workers.

Antibody activity to cotton dust bacteria in the nasal secretions of cotton-mill cardroom workers was studied using the ELISA technique. Secretion samples were collected by inserting a roll of filter paper into the nasal cavities of the subjects. The amount of secretion was significantly less among cotton-mill workers than workers in a wood factory. No significant differences were seen between byssinotic and nonbyssinotic cotton-mill workers. No significant differences were observed between cotton and wood workers regarding antibody activity against Pseudomonas syringae and Enterobacter agglomerans. Workers tested before and after the shift showed no difference in amount of secretion or in antibody activity. Smokers had a lower antibody activity than nonsmokers.

Adolescent↗

Cotton block method: one-step method of cell block preparation after fine needle aspiration.

OBJECTIVE: To describe the cotton block method, an easy, inexpensive, 1-step method of obtaining a cell block after fine needle aspiration biopsy. STUDY DESIGN: Before connection to a 10-mL syringe, the plastic hub of a 22-23-gauge needle is filled with the 3-4-mm, woolly tip of a cotton bud. Aspiration is performed as described elsewhere. After smear preparation, the material remaining in the needle and the material retained in the cotton wool mesh are immediately fixed by aspiration ofa fixative fluid (70% alcoholic formaldehyde-acetic acid). After fixation, the cotton tip is removed and routinely processed for paraffin embedding, and the sections are stained by routine methods used in cytopathology. RESULTS: The results demonstrate that the amount and quality of material obtained in the cotton wool tip is similar to that in the traditional cell block obtained from the pellet after centrifugation of aspirated fluid. CONCLUSION: The method is easy to perform and cost effective and is a rapid way to prepare cell blocks of high quality, allowing special staining techniques and improving cytohistologic correlation.

Biopsy, Fine-Needle↗

Cotton dust produces an increase in intraepithelial mucosubstances in rat airways.

Occupational exposure to endotoxin-contaminated organic dusts is associated with a variety of adverse pulmonary effects, including chronic bronchitis and sputum production. We have previously demonstrated in F344 rats that inhaled endotoxin rapidly induces an increase in the volume of stored intraepithelial mucosubstances (Vs) in the respiratory tract. The present study examined whether endotoxin-contaminated cotton dust can produce a similar increase in Vs in this animal model. Rats were exposed to air or 1.5 to 15.0 mg/m3 cotton dust for 2 h/d for 3 d. Twenty-four hours after the final exposure, the nasal cavity and lungs were fixed in formalin and the presence of Alcian blue/periodic acid-Schiff-staining mucosubstances determined by morphometry. Exposure to cotton dust produced concentration-dependent changes in Vs in the nasal septum and intrapulmonary airways. Statistically significant increases in Vs were observed in the epithelial lining of the nasal septum of animals exposed to 5.3 and 14.5 mg/m3 cotton dust (equivalent to 2.8 and 8.9 micrograms/m3 endotoxin). Vs in the intrapulmonary airways was also significantly increased at these concentrations. No significant changes were observed in the nasal septum or intrapulmonary airways after exposure to 1.8 mg/m3 cotton dust. These results are consistent with the hypothesis that endotoxin may contribute to the increase in human cases of chronic bronchitis reported in occupational settings in which endotoxin-contaminated dusts are encountered.

Animals↗

Toxicity of intratracheally instilled cotton dust, cellulose, and endotoxin.

Cotton dust includes respirable particles containing endotoxin and elastase, agents associated with emphysema. To examine whether a respirable fraction of cotton dust could produce emphysema in an animal model, we intratracheally instilled hamsters with respirable cotton dust particles (0.75 mg/100-g animal), mass median aerodynamic diameter less than or equal to 4.8 microns, twice weekly for 6 wk. We also examined whether instilled endotoxin (255 micrograms/100-g animal) could produce emphysema in hamsters and whether cellulose (0.75 mg/100-g animal) is an appropriate inert comparison dust. A saline-instilled group was the control. Hamsters were killed 8 wk after the last instillation. Static pressure-volume deflation curves of air-filled excised lungs were analyzed to measure lung distensibility. Lungs were fixed in inflation using glutaraldehyde and were examined morphometrically to obtain surface area and numbers of granulomata. Endotoxin-treated animals had increased distensibility, reduced surface-to-volume (S/V) ratio, and morphologically apparent mild centrilobular emphysema. Cellulose-treated animals had decreased distensibility, normal S/V ratio, and significant numbers of granulomata with patchy areas of thickened interalveolar septa. Cotton-dust-instilled animals had normal distensibility, reduced S/V ratio, significant numbers of granulomata, and mild centrilobular emphysema. These data suggest that cotton dust produces a significant parenchymal lesion with elements similar to both the emphysematous response to endotoxin and the fibrotic nodular response to cellulose.

Animals↗

Airway reactivity in cotton bract-induced bronchospasm.

Most healthy subjects challenged with cotton bract extract demonstrate some degree of bronchospasm. This response has been associated with the endogenous production of histamine by the inhalation of cotton bract extract. We examined whether this responsiveness reflects increased sensitivity to histamine. Thirty-one healthy subjects were screened for sensitivity to cotton bract extract administered by nebulization. Pulmonary function was measured using partial expiratory flow-volume curves on which flows at 60% of the control vital capacity below total lung capacity were measured (MEF40%(P)). Responders were defined as subjects who exhibited a 20% or greater decrease in MEF40%(P) after 10 min inhaling cotton bract extract. Of those screened, 10 subjects were responders. From the remaining nonresponders, 11 consecutive subjects were selected. The maximal decrease in MEF40%(P) in responders was 40.5 +/- 5.1%, compared to 10.9 +/- 2.2% in nonresponders. The dose-response relationship for histamine was measured in all subjects, using inhalations of progressively more concentrated histamine solutions. The mean +/- SEM threshold for the responders was 38.4 +/- 7.4 mg of histamine per ml, compared to 42.2 +/- 6.8 mg of histamine per ml for responders (difference not significant). The percentage decrease in MEF40%(P) at the threshold dose was 27.6 +/- 3.7% for responders and 32.4 +/- 5.2% for nonresponders (difference not significant). We conclude that healthy subjects sensitive to cotton bract extract do not exhibit increased reactivity to histamine. This suggests that responders are not, in general, subclinical asthmatics, and that the difference between responders and nonresponders to CBE is not due to increased histamine sensitivity among responders.

Adult↗

Fluorosis in a wild cotton rat (Sigmodon hispidus) population inhabiting a petrochemical waste site.

We have developed an in situ mammalian model for evaluating environmental contamination using wild cotton rats. In a series of experiments, 200 male cotton rats were captured during 4 collection periods (spring 1991 = 35; fall 1991 = 60; spring 1992 = 53; fall 1992 = 52). A total of 103 of these cotton rats were captured from control sites, and the remaining 97 were captured from an abandoned oil refinery. All sites were located in the vicinity of Cyril, Oklahoma. There were alterations in the incisors of cotton rats captured from the refinery site. Normal color of cotton rat incisors is deep yellow-orange, which is imparted by a pigment normally produced by ameloblasts. Grossly, the upper incisors of 37 of 97 rats and lower incisors of 54 of 97 rats were affected. The affected incisors were white, chalky, and thin with striations and erosions of the enamel. Microscopic examination revealed that there were dysplastic and necrotic changes in the ameloblasts. The bone fluoride levels were significantly higher in rats captured from the refinery as compared to the rats captured from the control sites.

Animals↗

Immunoglobulin administration and ribavirin therapy: efficacy in respiratory syncytial virus infection of the cotton rat.

We studied the effects of combined administration of human immunoglobulin (IVIG) and ribavirin aerosol on respiratory syncytial virus (RSV) infection in cotton rats (Sigmodon hispidus). Cotton rats assigned to receive combined therapy were administered Gamimune, a preparation of purified IVIG with a high titer of anti-RSV neutralizing activity, intraperitoneally 24 h prior to intranasal RSV challenge and then treated with ribavirin aerosol 3 days after challenge. Lung viral titers from these cotton rats (geometric mean titers [GMT] log10 = 0.15 +/- 0.5) were lower than titers from untreated animals (GMT, log10 = 3.7 +/- 0.6) and animals treated with either IVIG alone (GMT, log10 = 1.8 +/- 0.9) or ribavirin alone (GMT, log10 = 1.9 +/- 1.1). Only one of 12 cotton rats treated with both IVIG and ribavirin had a demonstrable titer of virus after RSV challenge. When IVIG administration was delayed until day 3 after virus challenge, lung viral titers were still lowest in animals receiving both IVIG and ribavirin. In comparison, there was no additive antiviral effect between IVIG and ribavirin against RSV infections of HEp-2 cells in vitro. Pathologic changes on histologic examination of pulmonary tissues from animals challenged with RSV were least prominent in animals treated with both IVIG and ribavirin. Despite the apparent absence of in vitro additive antiviral effect, combined use of IVIG and ribavirin was more efficacious against RSV infection in the cotton rat than use of either agent alone.

Animals↗

Enhanced protection against the migratory phase, but defective protection against the intestinal phase of Strongyloides venezuelensis infection in cotton rats, Sigmodon hispidus.

The protective capacity of the cotton rat, Sigmodon hispidus, against the migratory and intestinal phases of Strongyloides venezuelensis infection was examined. After subcutaneous infection with infective larvae (L(3)), adult worm recovery rates from male and female animals on Day 71 were only 0.10% and 0.06% of initial dose, respectively. To determine whether this enhanced protection was expressed during the migratory phase or the intestinal phase, larval recovery from the lungs of cotton rat was evaluated 3 days after subcutaneous L(3) infection. The larval recovery rate was only 0.5% of initial dose and about 40-fold lower than that from control mice. Protection in the intestine was also evaluated after intraduodenal implantation of adult worms. About 30% of implanted worms became established and worm burden remained constant until Day 28. Despite a high worm burden on Day 28, EPG was about 25-fold lower than the peak count. To evaluate expulsive capacity and monitor the cellular responses in the intestine of cotton rats, adult Nippostrongylus brasiliensis worms were implanted in addition to S. venezuelensis. Cotton rats were unable to expel adult S. venezuelensis worms, even after 21 days of observation. Although the number of mucosal mast cells increased significantly, the intraepithelial migration of mast cells was not observed. In contrast, N. brasiliensis was expelled by Day 6 in association with goblet cell hyperplasia. These results suggest that in cotton rats, the defective intestinal protection against adult S. venezuelensis worms results from dysfunction of mucosal mast cells.

Animals↗

Disseminated encephalitozoonosis in captive, juvenile, cotton-top (Saguinus oedipus) and neonatal emperor (Saguinus imperator) tamarins in North America.

Disseminated encephalitozoonosis was diagnosed in 2 sibling, juvenile, cotton-top tamarins (Saguinus oedipus) and 3 sibling, neonatal, emperor tamarins (S. imperator) by use of histologic examination, histochemical analysis, electron microscopy, and polymerase chain reaction (PCR) analysis with nucleotide sequencing. All tamarins were captive born at zoos in North America and died with no premonitory signs of disease. The main pathologic findings were myocarditis (4/5), hepatitis (3/5), interstitial pneumonia (3/5), skeletal myositis (3/5), meningoencephalitis (2/5), adrenalitis (2/5), tubulointerstitial nephritis (1/5), myelitis (1/5), sympathetic ganglioneuritis (1/5), and retinitis (1/5). Central nervous system lesions were the most prominent findings in cotton-top tamarins. The inflammation was predominantly lymphocytic and suppurative in cotton-top tamarins, whereas emperor tamarins had granulomatous or lymphoplasmacytic lesions. Intralesional periodic acid-Schiff-, gram-, or acid-fast (or all 3)-positive, oval-to-elliptical shaped organisms were found in 1 cotton-top and the 3 emperor tamarins. By electron microscopy, these organisms were consistent with microsporidia of the genus Encephalitozoon. E. cuniculi genotype III was detected by PCR analysis and sequencing in paraffin-embedded brain, lung, and bone marrow specimens from the cotton-top tamarins. Although PCR results were negative for one of the emperor tamarins, their dam was seropositive for E. cuniculi by ELISA and Western blot immunodetection. These findings and recent reports of encephalitozoonosis in tamarins in Europe suggest that E. cuniculi infection may be an emerging disease in callitrichids, causing high neonatal and juvenile mortality in some colonies. The death of 2 less than 1-day-old emperor tamarins from a seropositive dam supports the likelihood of vertical transmission in some of the cases reported here.

Adrenal Glands↗

Quantitative analysis of cotton-polyester textile blends from near-infrared spectra.

Quantitative analysis of textile blends and textile fabrics is currently of particular interest in the industrial context. In this frame, this work investigates whether the use of Fourier transform (FT) near-infrared (NIR) spectroscopy and chemometrics is powerful for rapid and accurate quantitative analysis of cotton-polyester content in blend products. As samples of the same composition have many sources of variability that affect NIR spectra, indirect prediction is particularly challenging and a large sample population is required to design robust calibration models. Thus, a total of more than three-hundred cotton-polyester samples were selected covering the range from the 0% to 100% cotton and the corresponding NIR reflectance spectra were measured on raw fabrics. The data set obtained was used to develop multivariate models for quantitative prediction from reference measurements. A successful approach was found to rely on partial least squares (PLS) regression combined with genetic algorithms (GAs) for wavelength selection. It involved evaluating a set of calibration models considering different spectral regions. The results obtained considering 27.5% of the original variables yielded a prediction error (RMSEP) of 2.3 in percent cotton content. It demonstrates that FT-NIR spectroscopy has the potential to be used in the textile industry for the prediction of the composition of cotton-polyester blends. As a further consequence, it was observed that the spectral preprocessing and the complexity of the model are simplified compared to the full-spectrum approach. Also, the relevancy of the spectral intervals retained after variable selection can be discussed.

Journal Article↗

Study of respiratory effect of short- and long-term cotton gin exposure.

No excess of obstructive airway disease was found in a group of 265 cotton gin workers when compared with other San Joaquin Valley agricultural workers. After an average of eight weeks' employment in San Joaquin Valley cotton gins, 125 workers showed no appreciable deterioration of pulmonary function compared with pre-employment measurements. In studies of pulmonary function during a workshift, cotton gin workers showed slightly greater mean decrements than control agricultural workers. These differences did not reach a level of statistical significance and were lower than those usually found in byssinosis. The unusual temporal pattern of employment in cotton gins in California precludes a simple approach to diagnosis by symptoms. No correlation was found in this study between symptoms of byssinosis and objective decrements in FEV1. The questionnaire as proposed by the Cotton Dust Standard was found to be of no value in detecting reactors in this study of gin workers.

Adolescent↗

Vegetable ingredients of dusts in textile and nontextile cotton industries.

The objective was to determine if garnetting and raw cotton dusts differed in botanical composition. Estimates of dust composition were based on the contents of gross trash in cotton raw materials and the potential of each gross trash component to be converted into less than 10 mum particulate by a laboratory abrasion test. All types of garnetting dusts are predicted to contain a lower percent content of leaflike material than raw cotton dust. Garnetting dusts arising from linter-polyester blends are estimated to contain only 20 to 25 percent of the concentration of leaflike ingredients predicted to be present in raw cotton dusts. The low prevalence of byssinosis reported in the garnetting industry may be explained, in part, by the relatively low percent content of leaflike particulate in this cotton dust.

Dust↗

Activity of rubidium and cesium in soybean looper (Lepidoptera: Noctuidae): insect feeding on cotton and soybean measured by elemental markers.

Uptake and translocation of the elemental markers rubidium (Rb) and cesium (Cs) within adult soybean looper, Pseudoplusia includens (Walker), were determined using atomic absorption spectrophotometry in the laboratory in various feeding and mating treatments. Neonates were tested to determine marker transfer from male and female adults fed rubidium chloride (RbCl)-treated artificial nectar, cesium chloride (CsCI)-treated artificial nectar, or both. All females contained detectable levels of Rb, Cs, or both, which were obtained either through direct feeding or via spermatophores. Rubidium was present in females at significantly greater levels than Cs. No significant differences in Rb levels were observed between feeding or spermatophore acquisitions. Most neonates had significantly higher levels of Rb than Cs. In a field cage study to evaluate adult feeding and oviposition behavior on blooming cotton and blooming soybean treated with RbCl and CsCl, respectively, more eggs contained Rb than Cs, indicating greater feeding on cotton nectar than soybean nectar, regardless of the host plant upon which eggs were laid. Females laid more eggs on blooming soybean than on blooming cotton. Higher levels of Rb in cotton than Cs in soybean were recorded and may be attributed to initial elemental marker quantities available to the insects. This study provides the support for the generalized observations that soybean looper infestations in soybean can be related to feeding activities by adults in cotton.

Animals↗