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PubMed1976

Variation in trash composition in raw cottons.

Raw cotton from 4 machine picked varieties and 2 machine stripped varieties is examined by stereomicroscope and bright-field microscopy for presence of plant trash(bract, leaf, stem, seed, boll, and weed fragments-size range 841-2000mum) that gives rise to cotton dust during yarn manufacturing operations. Bract was found to be the major trash component in all raw cottons examined. Cotton leaf and non-cotton weed materials were also major trash components in most raw cottons.

Byssinosis↗
PubMed1978

Evaluation of a fluorescent dust tracer technique in cotton ginning.

A technique employing a fluorescent tracer for following the break-up and dispersion of cotton trash has been developed. Senescent cotton leaves were treated with a fluorescent dye, pulverized to match the same particle size distribution as naturally occurring leaf in raw seed cotton and uniformly incorporated into the seed cotton mass prior to processing in a saw-type micro-gin. A control lot was similarly processed, excluding any dye. Airborne samples collected from the major fugitive dust emission points by standard techniques, macro trash samples collected from four locations, and the final condensed lint product clearly show that the use of such tracers is not only feasible but highly useful in determining the locations where respirable dust is emitted. From the fraction of labelled tracer material found at any site, the relative amounts of both total and respirable dust emissions of that plant component can be estimated from the known masses of dyed material added to a given mass of seed cotton. Estimates of the relative severity of fugitive dust emissions from various processing steps in a cotton gin are presented based on vertical elutriator, high volume and multistage cascade impactor sampler data.

Coloring Agents↗
PubMedDate not supplied

Byssinosis: thromboxane release from human platelets by cotton dust and bract extracts.

Extracts of cotton dust and bract induced in vitro release of arachidonic acid metabolite thromboxane A2 (TxA2), a potent bronchoconstricting agent, from human platelets. TxA2 release, determined by radioimmunoassay of the stabile metabolite TxB2, was both time- and dose-dependent. Cotton green bract extract was significantly more potent in releasing TxA2 from human platelets than cotton dust extract or cotton brown bract (field-dried bract) extract, while brown bract extract was least active, which suggests that the etiological agent(s) is of plant origin and not microbial in nature. TxA2 release was shown to be enzyme-dependent by inhibition of the reaction by indomethacin (cyclooxygenase inhibitor) and 7-(1-imidazolyl) heptanoic acid (thromboxane synthetase inhibitor). This study is the first to show in vitro platelet TxA2 release by cotton extracts and may provide an explanation for increased concentrations of TxB2, a metabolite of TxA2, in the bronchoalveolar spaces of rabbits exposed to aerosolized cotton dust extract. Platelet aggregation and production of TxA2 may prove to be an important mechanism in the pathogenesis of bronchoconstriction in byssinosis.

Blood Platelets↗
PubMed2001

Widespread risks of dental fluorosis in cotton rats (Sigmodon hispidus) residing on petrochemical waste sites.

Fluoride has been identified as a ubiquitous contaminant of soils where petrochemical wastes have been disposed. The purpose of this study was to assess how widespread toxicity risks are to resident vertebrates from chronic exposure to fluoride in the soil of petrochemical-contaminated waste sites. In total, 573 wild cotton rats (Sigmodon hispidus) were examined. The rats that were seasonally collected from 12 contaminated and 12 ecologically matched reference sites across Oklahoma over a 3-yr period. The risks of cotton rats exposed to fluoride were analyzed by means of gross examination, histopathology, and scanning electron microscopy of rat incisors. Cotton rats from reference sites showed no pathologic changes in incisors (98%). In comparison, 46% of cotton rats from contaminated sites had various degrees of dental lesions. The prevalence and severity of dental lesions in cotton rats from contaminated sites were significantly influenced by season. There was a 45% increase in prevalence and a 65% increase in severity of dental lesions from summer to winter. This study demonstrated that cotton rats are very sensitive biomonitors for assessing toxicity risks from soils contaminated with fluoride and that such assessments should consider seasonal influences.

Animals↗
PubMed1988

Serologic study of guinea pigs exposed for 12 months to cotton dust.

A guinea pig animal model of byssinosis has been described that demonstrates both acute and chronic effects of cotton dust inhalation (Ellakkani et al., 1984, 1987). During the latter study in which guinea pigs were exposed to 21 mg/m3 cotton dust 5 d/wk, 6 h/d for 52 wk, blood samples were taken from animals (20 exposed, 20 sham-exposed) prior to exposure and monthly during the exposure period. Sera were evaluated for quantities of the major protein fractions, and for IgG antibodies to cotton dust components. At the completion of the study, blood was evaluated for total and differential leukocytes. At 6 mo of exposure, each of the five protein fractions was significantly different from the corresponding fraction in the control animals. Antibodies reactive with an aqueous cotton dust extract (ACDE) were prominent by 2 mo of exposure and the titer was increased with continued exposure. The extract was composed of 2.6% protein, 12.8% reducing sugar, and 4.1% nucleic acid, with the remainder being largely simply sugars and inorganic material. A fraction of the antibodies showed reactivity with gram-negative bacteria and specifically with Enterobacter agglomerans, the most prevalent gram-negative microorganism in the dust. Minimal antibody response was detected using lipopolysaccharide from this microorganism or gram-positive bacteria. These results indicate that exposure of guinea pigs to cotton dust resulted in hematologic changes and in specific antibody formation. The presence of antibodies in each of the animals suggests their possible use as an indicator of cotton dust exposure.

Animals↗
PubMed1980

Capitate hairs on cotton textile wastes.

Bract and leaf samples from growing cotton plants and from cotton textile wastes were examined by scanning electron microscopy to determine if intact capitate hairs are important components fo raw cotton wastes. The density of capitate hairs on bract and leaf fragments in raw cotton was similar to that found on bracts and leaves from greenhouse and field collections. A bale of strict low middling raw cotton contains between 1.23 an 2.54 X 10(8) capitate hairs of bract origin alone. Capitate hairs could be important components of cotton textile wastes because of their abundance and because they contain chemicals that may be involved in the cause of respiratory disease in textile workers.

Gossypium↗
PubMed1987

Capillary gas chromatography of cotton dusts associated with human pulmonary function studies.

The effects of geographical area of growth and cotton variety on pulmonary activity have been evaluated through human volunteer exposure studies conducted by NIOSH and USDA at the Cotton Quality Research Station, Clemson, S.C. These studies demonstrate that carding California cottons releases dust with less human pulmonary activity than dust released from the corresponding Mississippi cottons. Dust released from Texas cottons grown in 1982 was considerably less active than the dust from Texas cottons grown in 1983. Distinct differences in the chemical compositions of the Mississippi, Texas, and California cardroom dusts were found. Aqueous extracts of the dusts were freeze-dried and then derivatized. Capillary gas chromatography revealed that the California dust extracts and the 1982 Texas dust extract were characterized by relatively higher levels of malic acid, whereas the Mississippi dust extracts and the 1983 Texas dust extracts were characterized by relatively higher mannitol levels.

Byssinosis↗
PubMed1987

Isolation and identification of gram negative bacteria from raw baled cotton and synthetic textile fibers with special reference to environmental GNB and endotoxin concentrations of textile mill.

The objective of this study was to examine the gram-negative bacterial (GNB) content of Indian raw baled cotton fibers and to compare with the U.S. cottons. Airborne endotoxin also was estimated in the different work places of the mill. On comparison with data on U.S. cottons, GNB content was found to be as high as in U.S. cottons. Moreover, endotoxin concentration of cardroom dust from an Indian cotton mill was found to be significantly (P less than 0.01) higher than in the research laboratory of the same cotton mill as well as in the cardroom of a synthetic mill.

Air Microbiology↗
PubMed2004

Effect of the red imported fire ant on cotton aphid population density and predation of bollworm and beet armyworm eggs.

The effects of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), on cotton aphid, Aphis gossypii Glover, populations and its predation of bollworm, Helicoverpa zea (Boddie), and beet armyworm, Spodoptera exigua (Hübner), (both Lepidoptera: Noctuidae) eggs were evaluated in cotton under field conditions during 2001 and 2002 in central and northern Texas. In central Texas, cotton aphid populations were approximately 5.5 times greater and predation of sentinel bollworm eggs 2 times greater in the presence of S. invicta versus in its absence, although aphid populations did not reach economic levels. Most predation of beet armyworm egg masses, measured via direct nocturnal observations, was due to S. invicta (68%) and cotton fleahopper, Pseudatomoscelis seriatus (Reuter) (21%), where S. invicta was present, and by the mite Abrolophus sp. (52%), spiders (13%), and minute pirate bug (Orius sp.) (13%) where S. invicta was absent. Predation of sentinel bollworm eggs and beet armyworm egg masses was approximately 1.5 and 4.1 times greater, respectively, in the presence of S. invicta versus in their absence. In the presence of S. invicta, the relative frequencies of minute pirate bug and cotton fleahopper were higher, and of S. invicta and native ants lower in beat bucket samples compared with their relative frequencies in nocturnal observations of predation upon beet armyworm egg masses. In the absence of S. invicta seven of eight predators sampled were similarly represented in beat bucket samples and nocturnal observations of beet armyworm egg mass predation, whereas minute pirate bug occurred at a higher frequency in beat bucket samples relative to nocturnal observations. These observations suggested that the relative frequencies of minute pirate bug, cotton fleahopper, S. invicta and native ants in beat bucket samples do not closely reflect the frequency with which these predators prey on noctuid eggs. Overall, the results of this study show that although S. invicta may promote aphid populations early in the growing season, it is an important predator of bollworm and beet armyworm eggs later in the season.

Animals↗
PubMed1996

Evaluation of permethrin-impregnated cotton balls as potential nesting material to control ectoparasites of woodrats in California.

The dusky-footed woodrat, Neotoma fuscipes Baird is a natural reservoir of the Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner, in California. To investigate the potential of host-targeted insecticide to control the tick vectors of B. burgdorferi, permethrin-impregnated or untreated cotton balls were distributed in metal cylinders as potential nesting material adjacent to 95 woodrat houses in chaparral-covered rangeland. Laboratory experiments demonstrated that adult woodrats would enter the cylinders and construct nests from permethrin-treated or untreated cotton. The residual concentration of permethrin did not vary significantly during an 11-mo period and remained > 60% of the registered insecticidal formulation (7.5% [AI] by cotton weight). The abundance of 4 species of ticks (Ixodes neotomae Cooley; the western blacklegged tick I. pacificus Cooley & Kohls; I. woodi Bishopp; and the Pacific Coast tick, Dermacentor occidentalis Marx) infesting woodrats was similar in the treatment and control areas. Although > 90% of the cotton disappeared from the metal cylinders in both areas, examination of 8 active woodrat houses revealed that small amounts of cotton had been incorporated into the nest cups of only 25%. In contrast, the abundance of the flea Orchopeas sexdentatus (Baker) decreased significantly in the treatment area only. Spirochetes were not detected in 168 adult O. sexdentatus fleas that had fed on spirochetemic woodrats, which demonstrates that this flea is an inefficient host of B. burgdorferi. We conclude that the use of permethrin-impregnated cotton as potential nesting material is ineffective for controlling ticks associated with the dusky-footed woodrat in brushlands, but this methodology may be useful for reducing populations of sylvatic fleas.

Animals↗
PubMed2005

Brassinosteroid regulates fiber development on cultured cotton ovules.

Our current understanding of the role of phytohormones in the development of cotton fibers is derived largely from an amenable culture system in which cotton ovules, collected on the day of anthesis, are floated on liquid media. Under these conditions, supplemental auxin and gibberellin were found to promote fiber initiation and elongation. More recently, addition of low concentrations of the brassinosteroid brassinolide (BL) were also found to promote fiber elongation while a brassinosteroid biosynthesis inhibitor brassinazole2001 (Brz) inhibited fiber development. In order to elucidate the role of brassinosteroid in cotton fiber development further, we have performed a more detailed analysis of the effects of these chemicals on cultured cotton ovules. Our results confirm that exogenous BL promotes fiber elongation while treatment with Brz inhibits it. Furthermore, treatment of cotton floral buds with Brz results in the complete absence of fiber differentiation, indicating that BR is required for fiber initiation as well as elongation. Expression of fiber genes associated with cell elongation increased in ovules treated with BL and was suppressed by Brz treatment, establishing a correlation between brassinosteroid-regulated gene expression and fiber elongation. These results establish a clear connection between brassinosteroid and fiber development and open the door for genetic analysis of cotton development through direct modification of the brassinosteroid signal transduction pathway.

Base Sequence↗
PubMed2001

Degradation of the sealing properties of a zinc oxide-calcium sulfate-based temporary filling material by entrapped cotton fibers.

During root canal therapy cotton may be placed in the pulp chamber before placement of a temporary filling. This study evaluated the effect on the sealing of a zinc oxide-calcium sulfate-based temporary filling material when fibers of the internal cotton passed through the filling material and reached the external surface of the temporary filling. Glass tubes were filled with a 3.5 mm thickness of the temporary filling incorporating a bundle of cotton fibers that passed from the inner surface of the restoration to the outer surface. The time for methylene blue stain to penetrate the filling was compared among four groups. Group 1 (large bundles of fibers) had 20 to 40 fibers, group 2 (medium bundles) had 10 to 15 fibers, group 3 (small bundles) had 3 to 5 fibers, and group 4 (negative controls) had no cotton fibers. All samples with cotton fibers leaked within 12 min. None of the negative controls leaked within the 21 -day observation time. These results demonstrate that even a very small amount of cotton trapped between the wall of the tube and the filling material dramatically reduced the sealing quality of the temporary restoration.

Calcium Sulfate↗
PubMed2005

Evaluation of Aa point and cotton-tipped swab test as predictors of urodynamic stress incontinence.

OBJECTIVE: To compare the predictive abilities of the Aa point of the pelvic organ prolapse quantification examination and the cotton-tipped swab test straining angle to diagnose urodynamic stress incontinence. METHODS: A case-control study was conducted between June 1997 and February 2003. Cases were defined as patients with urodynamic stress incontinence (n = 352). Controls were patients who also underwent urodynamic testing but who did not have a diagnosis of urodynamic stress incontinence (n = 245). Independent variables were defined as Aa point, Aa point of 0 or greater, straining cotton-tipped swab angle, and straining cotton-tipped swab angle of 30 degrees or greater. Logistic regression estimated the odds ratio of stress incontinence in women based on Aa values and cotton-tipped swab straining angle measurements, controlling for other variables commonly associated with stress incontinence. RESULTS: The mean (+/- standard deviation) age of the cases was 55.9 +/- 13.4 and of controls was 55.3 +/- 14.8, (P = .6). The median parity of the cases was 2 (range 0-10) and of controls, 2 (range 0-9) (P = .7). The Aa point was not associated with a diagnosis of stress incontinence (odds ratio 1.01, 95% confidence interval (CI) 0.83-1.23). The adjusted odds ratios of having an Aa value of 0 or greater was 0.49 (95% CI 0.26-0.92), and of having a cotton-tipped swab angle of 30 degrees or greater was 3.1 (95% CI 1.09-5.07), in a model that adjusted for age, parity, race, and postmenopausal and hormonal replacement status. CONCLUSION: Aa point is not associated with a diagnosis of stress incontinence. However, a cotton-tipped swab angle of 30 degrees or greater is positively associated with stress incontinence.

Case-Control Studies↗
PubMed1998

Dispersed repetitive DNA has spread to new genomes since polyploid formation in cotton.

Polyploid formation has played a major role in the evolution of many plant and animal genomes; however, surprisingly little is known regarding the subsequent evolution of DNA sequences that become newly united in a common nucleus. Of particular interest is the repetitive DNA fraction, which accounts for most nuclear DNA in higher plants and animals and which can be remarkably different, even in closely related taxa. In one recently formed polyploid, cotton (Gossypium barbadense L.; AD genome), 83 non-cross-hybridizing DNA clones contain dispersed repeats that are estimated to comprise about 24% of the nuclear DNA. Among these, 64 (77%) are largely restricted to diploid taxa containing the larger A genome and collectively account for about half of the difference in DNA content between Old World (A) and New World (D) diploid ancestors of cultivated AD tetraploid cotton. In tetraploid cotton, FISH analysis showed that some A-genome dispersed repeats appear to have spread to D-genome chromosomes. Such spread may also account for the finding that one, and only one, D-genome diploid cotton, Gossypium gossypioides, contains moderate levels of (otherwise) A-genome-specific repeats in addition to normal levels of D-genome repeats. The discovery of A-genome repeats in G. gossypioides adds genome-wide support to a suggestion previously based on evidence from only a single genetic locus that this species may be either the closest living descendant of the New World cotton ancestor, or an adulterated relic of polyploid formation. Spread of dispersed repeats in the early stages of polyploid formation may provide a tag to identify diploid progenitors of a polyploid. Although most repetitive clones do not correspond to known DNA sequences, 4 correspond to known transposons, most contain internal subrepeats, and at least 12 (including 2 of the possible transposons) hybridize to mRNAs expressed at readily discernible levels in cotton seedlings, implicating transposition as one possible mechanism of spread. Integration of molecular, phylogenetic, and cytogenetic analysis of dispersed repetitive DNA may shed new light on evolution of other polyploid genomes, as well as providing valuable landmarks for many aspects of genome analysis.

Amino Acid Sequence↗
PubMed1986

Diurnal fluctuations in cotton leaf carbon export, carbohydrate content, and sucrose synthesizing enzymes.

In fully expanded leaves of greenhouse-grown cotton (Gossypium hirsutum L., cv Coker 100) plants, carbon export, starch accumulation rate, and carbon exchange rate exhibited different behavior during the light period. Starch accumulation rates were relatively constant during the light period, whereas carbon export rate was greater in the afternoon than in the morning even though the carbon exchange rate peaked about noon. Sucrose levels increased throughout the light period and dropped sharply with the onset of darkness; hexose levels were relatively constant except for a slight peak in the early morning. Sucrose synthase, usually thought to be a degradative enzyme, was found in unusually high activities in cotton leaf. Both sucrose synthase and sucrose phosphate synthetase activities were found to fluctuate diurnally in cotton leaves but with different rhythms. Diurnal fluctuations in the rate of sucrose export were generally aligned with sucrose phosphate synthase activity during the light period but not with sucrose synthase activity; neither enzyme activity correlated with carbon export during the dark. Cotton leaf sucrose phosphate synthase activity was sufficient to account for the observed carbon export rates; there is no need to invoke sucrose synthase as a synthetic enzyme in mature cotton leaves. During the dark a significant correlation was found between starch degradation rate and leaf carbon export. These results indicate that carbon partitioning in cotton leaf is somewhat independent of the carbon exchange rate and that leaf carbon export rate may be linked to sucrose formation and content during the light period and to starch breakdown in the dark.

Journal Article↗
PubMed1985

Quantitative aspects of passive immunity to respiratory syncytial virus infection in infant cotton rats.

The amount of passively acquired serum respiratory syncytial virus (RSV)-neutralizing antibodies required to protect the respiratory tract of cotton rats against infection was studied. Infant cotton rats were inoculated intraperitoneally with various dilutions of a single pool of sera derived from cotton rats convalescent from RSV infection. After 24 h, these animals were inoculated with RSV intranasally. Virus replication in the respiratory tract was suppressed in cotton rats which had a serum neutralizing antibody titer of 1:100 or greater. Resistance was greater in the lungs than in the nose. Complete or almost complete resistance in the lungs was observed in cotton rats with a serum neutralizing antibody titer of 1:380 or greater. The level of serum RSV-neutralizing antibodies required to confer significant resistance to infection in the cotton rat was similar to the level of maternally derived serum antibodies possessed by human infants less than 2 months of age, who as a group exhibit relative resistance to RSV disease compared with infants 2 to 6 months of age.

Animals↗
PubMed2005

The cotton rat (Sigmodon hispidus) is a permissive small animal model of human metapneumovirus infection, pathogenesis, and protective immunity.

Human metapneumovirus (hMPV) is a newly described paramyxovirus that is an important cause of acute respiratory tract disease. We undertook to develop a small animal model of hMPV infection, pathogenesis, and protection. Hamsters, guinea pigs, cotton rats, and nine inbred strains of mice were inoculated intranasally with hMPV. The animals were sacrificed, and nasal and lung tissue virus yields were determined by plaque titration. None of the animals exhibited respiratory symptoms. The quantity of virus present in the nasal tissue ranged from 4.6 x 10(2) PFU/gram tissue (C3H mice) to greater than 10(5) PFU/gram (hamster). The amount of virus in the lungs was considerably less than in nasal tissue in each species tested, ranging from undetectable (<5 PFU/g; guinea pigs) to 1.8 x 10(5) PFU/gram (cotton rat). The peak virus titer in cotton rat lungs occurred on day 4 postinfection. hMPV-infected cotton rat lungs examined on day 4 postinfection exhibited histopathological changes consisting of peribronchial inflammatory infiltrates. Immunohistochemical staining detected virus only at the luminal surfaces of respiratory epithelial cells throughout the respiratory tract. hMPV-infected cotton rats mounted virus-neutralizing antibody responses and were partially protected against virus shedding and lung pathology on subsequent rechallenge with hMPV. Viral antigen was undetectable in the lungs on challenge of previously infected animals. This study demonstrates that the cotton rat is a permissive small animal model of hMPV infection that exhibits lung histopathology associated with infection and that primary infection protected animals against subsequent infection. This model will allow further in vivo studies of hMPV pathogenesis and evaluation of vaccine candidates.

Animals↗
PubMed1994

Ocular and nasal irritation in operatives in Lancashire cotton and synthetic fibre mills.

OBJECTIVES: To document the prevalence of work related ocular (eyeWRI) and nasal (noseWRI) irritation in workers in spinning mills of cotton and synthetic textile fibres and to relate the prevalence of symptoms to atopy, byssinotic symptoms, work history, and measured dust concentrations in the personal breathing zone and work area. METHODS: A cross sectional study of 1048 cotton workers and 404 synthetic fibre workers was performed. A respiratory questionnaire was given to 1452 workers (95% of the total available population). Atopy was judged by skin prick tests to three common allergens. Work area cotton dust sampling (WAdust) was carried out according to EH25 guidelines in nine of the 11 spinning mills included in the study. Personal breathing zone dust concentrations were assessed with the IOM sampler to derive total dust exposure (PTdust) and a concentration calculated after the removal of fly (Pless). RESULTS: 3.7% of all operatives complained of symptoms of byssinosis, 253 (17.5%) complained of eyeWRI and 165 (11%) of noseWRI. These symptoms did not relate to atopy or byssinosis, or correlate univariately with any measure of cotton dust exposure (noseWRI v WAdust r = 0.153, PTdust r = 0.118, eyeWRI v WAdust r = 0.029, PTdust r = 0.052). Both of these symptoms on logistic regression analysis were related to being of white origin (P < 0.001), female sex (P < 0.001), and younger age (P < 0.001). With regression analysis, there was a negative relation between dust concentration and prevalence of symptoms. CONCLUSION: Work related ocular and nasal irritation are the most common symptoms complained of by cotton textile workers. There was no relation between these symptoms and atopy, byssinosis, or dust concentration. It is likely that they relate to as yet unidentified agents unrelated to concentration of cotton dust.

Adult↗