Publications by authors named "Steffens W"

Context: Diisocyanates have been associated with respiratory and dermal sensitization. Limited number of case reports, and a few case studies, media, and other references suggest potential neurotoxic effects from exposures to toluene diisocyanate (TDI), 1,6 hexamethylene diisocyanate (HDI), and methylene diisocyanate (MDI). However, a systematic review of the literature evaluating the causal association on humans does not exist to support this alleged association.

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Avian thymic hormone (ATH) is a β-parvalbumin produced by epithelial cells in the thymic cortex and in the eyes of chickens. Chicken parvalbumin 3 (CPV3) is a homologous protein produced in the thymus and in hair cells of the chicken ear. ATH circulates in the blood on a five-day cycle and stimulates cell-mediated immunity when administered to young chickens.

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Adenovirus infections are documented in at least 12 different species of reptiles. In contrast to their mammalian and avian counterparts reptilian adenoviruses are not well characterized as to their pathogenic potential and their ability to cause primary disease. In the diagnostic setting, fresh tissues are often not available for virus isolation, and the confirmation of reptilian adenovirus infections is dependent largely upon electron microscopy for the identification of intranuclear viral inclusions associated with histopathologic changes.

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A comparative evaluation of the location of immunoreactive porcine zona pellucida (pZP) glycoproteins was performed with polyclonal rabbit anti-pZP antibodies on ovarian sections of the dog, cat, horse, and elephant. For this, formalin (light microscopy) and glutaraldehyde (transmission electron microscopy [TEM]) fixed ovarian sections were incubated with antibodies raised against highly purified pZP. Staining patterns were determined with diaminobenzidine (DAB) at the light level.

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The primary objective of this study was to determine the effects of diets containing 18% or 34% protein on glomerular mesangial area (GMA) and basement membrane thickness (GBMT) in uninephrectomized aged dogs. A secondary objective was to determine the combined effects of aging and uninephrectomy on GMA and GBMT in dogs. Ten clinically healthy, pure-bred dogs were unilaterally nephrectomized at about 8 y of age.

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During a 6 mo study of moribund trout from Buford hatchery, Buford, Georgia, USA, a Loma cf. salmonae microsporidian parasite was studied in the gills of brook trout Salvelinus fontinalis, brown trout Salmo trutta, and rainbow trout Oncorhynchus mykiss. This parasite was morphologically similar to L.

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Lafora bodies (polyglucosan deposits) were identified in the brain of a young adult cat with neurologic signs characterized by intermittent but progressively worsening head and body tremors. The cerebellar cortex was the most severely affected area of brain, and the deposits were identified within Purkinje cell bodies and processes and throughout the neuropil. The association of Lafora bodies with neurologic signs, occurrence of deposits within neuronal perikarya, and distribution primarily within the cerebellar cortex are features distinct from the more commonly recognized situation in which Lafora bodies occur as incidental lesions in cats.

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Recombinant plasmid pHK11 was transformed into an avirulent, wild-type avian Escherichia coli (E. coli Av) in order to study the plasmid's effect on colonization of the chicken trachea. The transformant (E.

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Escherichia coli establishes a secondary respiratory tract infection in birds following inhalation of contaminated dust and litter particles. Escherichia coli express adhesins under conditions reflective of the ambient temperatures present in poultry houses. These microbial adhesins allow E.

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Formaldehyde gas used to fumigate hatcheries for control of microbial contamination has an adverse effect on tracheal cilia function and morphology. Evaluation of the changes revealed alterations in the ultrastructure of the axoneme with the absence of B subfibers and the production of additional A subfibers. Spikes and vesicular blebs in the cilia walls were evident in formaldehyde-exposed cilia.

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An adult female canebrake rattlesnake (Crotalus horridus atricaudatus) at Zoo Atlanta (Atlanta, Georgia, USA) had a subcutaneous mass on the left lateral abdomen. Microscopically, the tumor contained a pleomorphic population of cells with abundant intracytoplasmic brown to gold nonrefractile pigment (chromatophores), large stellate cells resembling neurons, and small stellate cells whose cytoplasmic processes formed a fibrillar matrix. The pigment stained black with the Fontana-Masson technique and was positive with the periodic acid-Schiff technique (prior to and after diastase treatment).

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Immunoprobes are used in the qualitative and semi-quantitative demonstration of antigens in clinical samples. In the present study, an immunogold method has been used for routine and rapid detection of avian leukosis/sarcoma virus (AL/SV) in sections of formalin-fixed chicken heart and kidney. Application of this ultrastructural indirect immunogold labelling technique (IILT) will enable pathologists to obtain a definitive diagnosis of avian AL/SV infection when inclusions or putative viral particles are observed by light or electron microscopy.

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Pyrethroids have varying activities depending on vehicle or route of administration (oral, dermal, inhalational). Specific features like the sensory irritation potential of the alpha-cyano-pyrethroids on the respiratory tract can only be quantified adequately by inhalation testing. Thus equitoxic dosages can vary between inhalative and oral application, especially for alpha-cyano-pyrethrolds.

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Necropsy tissues were examined from an adult wild-caught Ducorps' cockatoo (Cacatua ducorpsii) with progressive neurologic signs. Of the tissue specimens selected for histologic evaluation, only the brain contained rare amphophilic, glassy intranuclear inclusions within astrocytes and some neurons. Astrocyte and neuronal degeneration and necrosis also were observed.

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In a laboratory construction for heterotrophic biological denitrification of drinking water treatment, the formation of nitrite, the potency of nitrosation and the genotoxic activity were tested. Parameter as nitrate concentration, the water flow rate in the system, nitrite and morpholine addition and the pH-value were checked. For testing the potency of nitrosation and formation of nitrite in the reactor we took morpholine, a fast nitrosing amine.

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Eastern equine encephalomyelitis (F.EE) virus was detected in infected formalin-fixed horse and emu tissues and in infected chicken embryo fibroblasts. Results of in situ hybridization using a digoxigenin-labeled 40-base DNA probe complementary to a conserved region of the EEE virus RNA compared favorably with results of both virus isolation and serum neutralization tests.

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Although carp is in a position to utilize carbohydrates efficiently, lipids are an important energy source in carp diets. In general fat-enriched high-energy diets result in rapid growth and favourable feed conversion. Many authors emphasize the protein-sparing effect of lipid supplementation in carp diets.

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The purpose of the present study was to use clinical epidemiologic tools to define the relationship between production performance data, virus particles, and intestinal fringed membranous particles (FMPs) in healthy turkey poults and in poults that were experiencing an outbreak of poult enteritis complex (PEC) and spiking mortality syndrome (SMS). Small and large intestines from flocks of healthy poults and poults with PEC/SMS were collected, processed, and examined for viruses. Production performance parameters were collected and analyzed.

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With a new ultrahigh-vacuum deposition/ref lectometer system, Mo/Y multilayer mirrors were deposited by dc-magnetron sputtering and characterized in situ with synchrotron radiation. The Mo/Y multilayer mirrors, measured before exposure to air, had near-normal-incidence reflectances as high as 46% at wavelengths near 11.4 nm.

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The suitability of various vegetable and fish oils was tested as feed components for one-summer-old carp fingerlings. Five diets were used: a basal diet, which served as control feed, was supplemented with 10% corn-germ oil, 10% sunflower oil, 10% fish oil or 10% rapeseed oil, respectively. By means of the lipid supplementation the crude protein content decreased from 35.

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Four adult dogs received experimentally controlled stings in the dorsolateral abdominal skin by imported fire ants (Solenopsis invicta). The sites were examined grossly 15 minutes and at 1, 2, 3, 4, 5, 6, 24, 48, and 72 hours and histologically 15 minutes and 6, 24, 48, and 72 hours after stinging. The initial gross lesions at 15 minutes were swelling and erythema, and the microscopic changes were vascular congestion and superficial dermal edema.

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