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At least 343 records · Page 19Linked to original sources
PubMed1990

Prevalence and effect of subclinical ovine progressive pneumonia virus infection on ewe wool and lamb production.

The prevalence of infection with ovine progressive pneumonia (OPP) virus and its effects on ewe wool and lamb production were investigated in a flock of 2,976 ewes of 6 breed types (Rambouillet, Targhee, Columbia, Polypay, 1/4 cross Finnsheep, and 1/2 cross Finnsheep). Prevalence of seropositivity was significantly (P less than or equal to 0.01) lower among Rambouillet and Targhee breeds (44 and 42%, respectively), intermediate in Polypay, Columbia, and 1/4 cross Finnsheep (approximately 53%), and higher among 1/2 cross Finnsheep (62%). Seropositivity increased with age in all breed types from 11% at 1 year of age to 93% at greater than or equal to 7 years of age. Lateral disease transmission is indicated by linear increase of seropositivity prevalence with increasing age, including that in sheep greater than 6 years old. Subclinical infection with OPP virus had no apparent detrimental effect on number of lambs born, lamb viability, birth weight, number of lambs weaned, or growth rate of single and twin lambs, compared with findings for noninfected sheep in the same flock. Mature ewe body weight and grease fleece weight did not differ between subclinically infected seropositive and seronegative ewes. Subclinical infection with OPP virus does not appear to have an adverse economic effect on ewe wool and lamb production. Culling rate attributable to clinical manifestation of infection with OPP virus must be accurately determined before the true effects of virus infection on production can be determined and an eradication program can be recommended.

Age Factors↗
PubMed1990

[Current hygiene problems and main risk factors in wool industry].

The labour conditions of the workers engaged in raw wool manufacturing are characterized by irrational management of the technological processing, inadequate labour and rehabilitation regimen, nutrition, organization of social and medical services for those engaged in shearing, as well as by incompatibility of the industrial sites to the existing hygienic and technological requirements. All this accounts for the high relevance of respiratory diseases (42%), and inflammatory and allergic diseases of the skin and subcutaneous fat, which are etiologically related to wool dust's action. The contributors propose newly elaborated hygienic recommendations and occupational health related standards designed to promote prevention of these diseases and elimination of industrial risk-factors.

Animals↗
PubMed1983

Retardation of wool growth in Merino sheep caused by bacteria.

A condition evidenced by retarded growth of wool with alteration of the yolk into a yellow, sticky, wax-like substance was investigated. The condition was associated with hyperaemia and cellular infiltration into the dermis in the affected areas. Three bacterial species, viz. Enterobacter aerogenes, E. agglomerans and Hafnia alvei, which could grow on the water-extractable component of wool-yolk, were incriminated as the cause of the condition.

Animals↗
PubMed1982

Defleecing effect of betamethasone and other long-acting corticosteroids, their influence on wool growth and some physiological processes in sheep.

The defleecing effects of the long-acting derivatives of prednisolone, triamcinolone and dexamethasone were compared with those of betamethasone alcohol when these steroids were administered at the rate of 3.3 mg/kg liveweight in three equal intramuscular injections of 1.1 mg to Merino wethers. Prednisolone showed no defleecing activity whereas the other steroids produced positive but variable responses. Prolonged depression of wool growth was evident following treatment with dexamethasone esters. Betamethasone alcohol injected intramuscularly at 1.1 mg/kg daily for 3 days produced a similar defleecing response to intravenous infusion of 3.3 mg/kg betamethasone phosphate over 8 days. A range of dose rates (0.3-3.3 mg/kg) of betamethasone as multiple and single intramuscular injections indicated that the minimum effective defleecing dose was approximately 2.1 mg/kg. The response to simultaneous administration of betamethasone and insulin or chlorpropamide (to increase glucose utilization) and glucose or xylazine (to increase hyperglycaemia) suggested that the gluconeogenic role of this steroid had little effect on fibre shedding. Thyroxine (300 micrograms per sheep) administered on the first day with an injection of betamethasone (0.9 mg/kg), and alone daily for 20 days thereafter, did not influence the changes in wool production resulting from betamethasone treatment. These results are discussed in relation to the molecular structure and physiological characteristics of a potentially specific defleecing steroid.

Adrenal Cortex Hormones↗
PubMed1980

Patterns of wool moisture in merino sheep and its associated with blowfly strike.

A method for determining the moisture content of wool with a minimum disturbance to the constituents is described. The method was used to show differences in moisture content according to anatomical site, age, sex, strain of merino and in lesions of fleece rot, bacterial stain and active flystrike. The incidence of natural flystrike was recorded and related to the higher levels of moisture content. The moisture content in proximal wool was found to increase at different rates, following wetting of the fleece with droplets of water falling under gravity to simulate rain. A level of 20 per cent moisture content was reached after different time intervals in different strains of merino sheep, which may explain one of the differences in strain susceptibility to fleece rot

Animals↗
PubMed1977

Parasitism (Trichostrongylus colubriformis and Eimeria ninakohlyakimovae) in sheep: relationship between wool fiber diameter changes and feed conversion efficiency.

Twenty-five lambs, 5 months of age, were used to compare the infection pressure of Trichostrongylus colubriformis with that of Eimeria ninakohlyakimovae. Effects of the parasitic infection pressure were assayed by determining body weight gains, feed conversion efficiencies, and wool fiber diameter changes (reflecting changes in protein metabolism) in lambs fed a good ration and those given a marginal diet (dehydrated alfalfa pellets). Significant differences in weight grains or feed conversion efficiencies of nematode- or coccidia-infected lambs and noninfected controls were not found, but significant differences due to the parasites' effect on wool fiber diameters and in lamb response to different feeds were found. Protein uptake or assimilation, or both, were apparently affected by a combination of infection with E ninakohlyakimovae and a marginal diet.

Animal Feed↗
PubMedDate not supplied

[Promotion of wool growth and body weight development of sheep by alimentary supplementation with thiocyanate].

Adult sheep were administered 12 mg thiocyanate (SCN-)/kg body weight orally twice a year in altogether 16 respectively 41 single doses under conventional keeping during the period of stabling (winter) in two consecutive years. Fattening lambs got an analogous SCN- dosage with altogether 4 respectively 34 single doses under intensive keeping. Aided by this temporarily obtained balance of an alimentary SCN- deficiency the following effects were reached during conventional keeping: Significant increase of the wool mass in the greasy state and a tendency to better breading performance. During intensive fattening an increase of the wool mass and of the staple cross-section was proven statistically in the mean for all the test animals, but for the increase of the staple length it could be shown only by comparison of twins.

Aging↗
PubMed1978

Increased pulmonary arteriovenous shunting in humans following blood transfusion. Relation to screen filtration pressure of transfused blood and prevention by Dacron wool (Swank) filtration.

Transfusion through standard filters to dogs of stored blood containing microaggregates results in an increase in pulmonary arteriovenous shunting (Qs/Qt) and a decreased diffusion capacity of the lung for O2. These effects are due to microemboli that pass the filters and are prevented by use of Dacron wool (Swank) micropore transfusion filters. It was the purpose of this study to determine whether alterations in pulmonary shunting occur in humans following transfusions of stored blood through standard transfusion filters. In eight patients transfused over 20% of blood volumes through standard filters, Qs/Qt and alveolar-arterial O2 tension differences increased significantly. These changes did not occur in patients transfused comparable amounts of blood through Dacron wool (Swank) filters or in patients transfused less than 20% of blood volumes. A direct correlation was found between the absolute percent change in Qs/Qt and the quantity of microaggregates passing the filter and present in the transfused blood. It is concluded that removal from stored blood of microaggregates by administration of the blood through effective micropore transfusion filters prevents an increase in Qs/Qt caused by administration of such material.

Adult↗
PubMed2001

The use of glass wool as an attachment surface for studying phenotypic changes in Pseudomonas aeruginosa biofilms by two-dimensional gel electrophoresis.

Two-dimensional polyacrylamide gel electrophoresis was used to demonstrate phenotypic differences between Pseudomonas aeruginosa biofilm cells and the planktonic counterpart cells under defined culture conditions. Glass wool was used as a substratum for cell attachment as it affords a large surface-to-volume ratio (1 g with a mean diameter of 15 microns = 1300 cm2), supports the growth of biofilms, allows for free movement of cells between the inter-strand spaces, and it facilitates the exchange of nutrients and oxygen. It also allows for the separation of the biofilm biomass from the surrounding surface influenced planktonic (SIP) cells for further characterization. Comparative analysis of the respective proteomes indicated striking differences in the protein patterns of planktonic, biofilm and SIP cells. We selected 41 proteins, the levels of which varied in a significant and reproducible way in the respective protein profiles. In the biofilm cells, a general up-regulation of the spots was seen, but in SIP cells expression of these spots were generally down-regulated. Altogether six unique proteins were seen in the planktonic cells, while the biofilm and SIP cells contained five and two unique proteins, respectively. Glass wool, therefore, appears to be an ideal attachment surface for the study of biofilm development.

Bacterial Adhesion↗
PubMed2006

Pulmonary fibrosis in a patient with exposure to glass wool fibers.

Glass wool or vitreous fibers are non-crystalline, fibrous inorganic substances (silicates) made primarily from rock, slag, glass, or other processed minerals. They belong to the man-made mineral fibers (MMMFs) group and their respiratory effects are well described by De Vuyst et al. [1995]. The authors pointed out the absence of firm evidence that exposure to these fibers is associated with lung fibrosis, pleural lesions, or non-specific respiratory disease in humans. Because of this observation, we find it of importance to present a case of interstitial fibrosis, which implies a direct association between long-term exposure to glass wool and the clinical outcome.

Adult↗
PubMed2002

High-alumina low-silica HT stone wool fibers: a chemical compositional range with high biosolubility.

Man-made vitreous fibers (MMVF) are classified within the European Union (EU) as carcinogenic category 3 (possibly carcinogenic), but criteria exist to exonerate fibers from this classification. The HT stone wool fiber type is a MMVF that fulfills European regulatory requirements for exoneration from classification as a carcinogen based on in vivo testing. The chemical composition of the fibers and the results of the in vivo and in vitro studies that defined the chemical compositional range for a CAS registry number for these fibers are presented and discussed. Results from in vitro dissolution measurements at pH 4.5 of 52 fiber compositions (9-23 wt% Al(2)O(3) and 32-47 wt% SiO(2)) ranging from traditional stone wool to the biosoluble HT fibers are presented. The results are evaluated as a function of the ratio Al/(Al+Si) in the glass network and as a function of the fraction of Si-O-Si linkages in the glass. It is suggested that the dissolution mechanism for these fibers relates to the density of the surface silica layer on dissolving fibers and that the fraction of Si-O-Si linkages influences this.

Aluminum Oxide↗
PubMed1989

Glass wool-filtered spermatozoa and their oocyte penetrating capacity.

The capacity of glass wool-filtered spermatozoa to penetrate zona-free hamster oocytes was studied. As compared to prefiltered sperm samples, oocyte penetration was significantly increased. A significant increase in the penetration rate for the filtered sperm population was noted even after the sperm motility in the filtrate was adjusted with medium equal to that of the prefiltered sample. However, no significant differences in oocyte penetration were seen between the prefiltered and the filtered sperm population when the filtered sperm samples were diluted with nonviable spermatozoa. These results show that glass wool filtration yields a sperm population with a greater penetrating capacity. It was concluded that motility alone could not account for the improved penetrability and that the removal of nonviable spermatozoa may at least, in part, be responsible for this effect.

Female↗
PubMed1977

Stored blood microfiltration. Evaluation of micro-aggregate filter composed of polyurethane foam and nylon wool.

Aggregates of amorphous material which develop during storage of banked blood have been implicated as a cause of pulmonary micro-embolism in man following massive transfusion. Such pulmonary micro-embolism may be a causal factor in the development of post traumatic pulmonary insufficiency. At present several microaggregate filters for use in massive transfusion are commercially available, and on of these is the Fenwal filter. It is composed of a screen filter which removes microclots of 250 microns and higher, a layer of polyurethane foam and a layer of nylon wool. The resistance of this device is very acceptable and the filter may be used for several blood units, but its efficiency seems less than that of Dacron wool filter.

Blood Platelets↗
PubMed1985

Suppression of the antibody response by phorbol esters in the mouse is due to an effect on the nylon wool adherent cell population.

Phorbol esters, in particular 12-O-tetradecanoyl-phorbol-13-acetate (TPA), have been shown to have profound effects on most biological systems including tumor promotion. Presented here are studies on the acute toxic effects of TPA, and the effects of phorbol esters on the in vivo and in vitro, T cell-dependent, antigen-specific antibody response in the mouse. The LD50 of a single i.v. dose of TPA in the mouse was 309 micrograms/kg. Acute toxic effects included lethargy, hypothermia and enlarged, hemorrhagic spleens at the higher doses. TPA was shown to be a potent inhibitor of the in vivo primary antibody response as measured by the IgM antibody-forming cell (AFC) response to sheep red blood cells (sRBC). The ED50 of a cumulative i.v. dose was 145 micrograms/kg administered the day before and the day of immunization (72.5 micrograms/kg/day). A cumulative dose of 500 micrograms/kg (250 micrograms/kg/day) resulted in a 100% suppression of the response. This in vivo exposure to TPA did not alter B cell/T cell ratio in the spleen. Phorbol ester analogs inactive in other biological systems were also inactive in the in vivo AFC response. The in vitro AFC assay was used to determine what cell type was being affected by TPA. Separation of the adherent spleen cells into B and T cell populations was done using nylon wool columns and anti-theta plus complement treatment. Experiments with these cell populations indicated that TPA produced suppression of the response due to an effect on the nylon wool adherent cell population.

Animals↗
PubMed1994

Growth of wool follicles in culture.

A procedure for the culture of isolated wool follicles from Merino sheep is described. Follicles were microdissected from midside skin samples of 2-yr-old wethers and transferred, individually, to 24-well tissue culture plates. When maintained in supplemented Williams' E medium containing 5 to 10% fetal bovine serum (FBS), insulin, hydrocortisone, and a trace element mixture, fibre growth rates of 40 to 80 microns/day were observed. Follicles maintained their morphologic integrity for up to 7 days, incorporated [methyl-3H]thymidine into DNA and [35S]methionine into intermediate-filament keratins of the growing fiber. Insulin and hydrocortisone stimulated fiber growth at concentrations of 10 micrograms/ml and 50 ng/ml, respectively, but higher doses were inhibitory. The growth of fibers in response to hydrocortisone and the changes in follicle morphology was similar to those induced in skin after systemic administration of cortisol in vivo. A positive interaction between hydrocortisone and trace elements for follicle survival and hydrocortisone, insulin, and FBS for fiber growth was also found. The successful culture of Merino sheep follicles provides a model with which to study the direct influence of endocrine, nutritional and local factors on wool keratin synthesis independently of systemic shifts in the animals' metabolism.

Aging↗
PubMed1981

A comparison of Lyoband with cotton wool as a lining for plaster casts.

Polyurethane foam bandage (Lyoband) was compared with conventional cotton wool bandage of similar dimensions as a lining in below-knee walking plasters used for the immobilization of fractures of one malleolus. A device was designed to measure the potential space between the limb and the plaster and therefore the loosening of the cast. By virtue of its expansile nature, the Lyoband lining proved a considerably more satisfactory material than cotton wool bandage.

Bandages↗
PubMed1981

HLA-DR typing: a comparison between nylon wool adherence and T cell rosetting in the isolation of B cells.

A comparison was made between two different methods of B cell isolation, nylon wool adherence versus SRBC rosetting in terms of the technical ease of B cell purification and the reproducibility of DR phenotyping. It was found that B cells isolated by either method from 30 randomly selected donors gave equivalent results in the determination of DR phenotypes. Due to its simplicity and reliability, nylon wool adherence may be preferred over the SRBC rosette method for the routine phenotyping of B cells.

Animals↗
PubMed1983

Effects of long-term consumption of sewage solids on reproductive performance and serum progesterone and estradiol-17beta in mature fine-wool ewes.

Eighty-four mature fine-wool ewes were randomly allotted to one of three dietary treatments to examine the influence of dietary sewage solids on reproductive performance. Treatments were a basal diet or basal plus either 3.5% cottonseed meal (CSM) or 7% sewage solids. Serum progesterone and estradiol-17beta measured in blood samples collected through an estrous cycle just before the breeding season of the first and second years were not adversely influenced by sewage feeding. Progesterone concentrations quantified in weekly blood samples collected during gestation and lactation of both years did not differ (P>0.10) among treatments. During the first lambing season, lambing data showed that ewes consuming CSM produced slightly more lambs per ewe exposed (P<0.10) than either basal- or sewage-fed ewes. During the second breeding season, midventral laparotomies revealed that ovaries from ewes receiving CSM contained more (P<0.10) corpora lutea than did those from either basal- or sewage-fed animals. However, at the end of the second lambing season, no differences (P>0.10) among treatments in the number of lambs born or weaned were observed. A third year's lambing data also revealed no difference (P>0.10) among treatments for lambing rates. These data indicate that prolonged consumption of a diet containing 7% sewage solids has little, if any, detrimental effect on reproductive performance of mature fine-wool ewes.

Journal Article↗