Search

Transmissible spongiform encephalopathies (TSEs), or prion diseases, are neurodegenerative diseases that affect many mammalian species. Some examples include bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep and goats, Creutzfeldt-Jakob [...]

Staphylococcus aureus community-acquired pneumonia is often associated with influenza or an influenza-like syndrome. Morbidity and mortality due to methicillin-resistant S. aureus (MRSA) or influenza and pneumonia, which includes bacterial co-infection, are among the top causes of death by infectious diseases in the United States. We developed a non-lethal influenza A virus (IAV) (H3N2)/S. aureus co-infection model in cynomolgus macaques (Macaca fascicularis) to test the hypothesis that seasonal IAV infection predisposes non-human primates to severe S. aureus pneumonia. Infection and disease progression were monitored by clinical assessment of animal health; analysis of blood chemistry, nasal swabs, and X-rays; and gross pathology and histopathology of lungs from infected animals. Seasonal IAV infection in healthy cynomolgus macaques caused mild pneumonia, but unexpectedly, did not predispose these animals to subsequent severe infection with the community-associated MRSA clone USA300. We conclude that in our co-infection model, seasonal IAV infection alone is not sufficient to promote severe S. aureus pneumonia in otherwise healthy non-human primates. The implication of these findings is that comorbidity factors in addition to IAV infection are required to predispose individuals to secondary S. aureus pneumonia. [ABSTRACT FROM AUTHOR]

2,4,6-Trichlorophenol (TCP) has been found in drinking water as a result of its use as a fungicide and due to its inadvertent production in the water purification process. This study was conducted since information on the toxicity from repeated ingestion was inadequate. Male and female Sprague-Dawley rats were gavaged with TCP administered in corn oil (2 ml/kg body weight) for 90 consecutive days at dose levels of 0, 80, 240, and 720 mg/kg per day. Treatment-related effects were observed at the highest dose (720 mg/kg/day) and consisted of salivation, urine stains on the fur, increase in absolute and relative weights of the kidneys, liver, adrenal glands, and testes. At this dose, increases were seen in serum protein, albumin, and alanine aminotransferase (ALT), with a decrease in urinary pH. Some effects observed at 240 mg/kg per day were an increase in the absolute and relative weights of the liver and adrenal glands in females, relative liver weights in males, and an increase in serum albumin in males. No treatment-related effects were observed at 80 mg/kg per day. No mortality or significant effects were observed at any dose level for body weight, food consumption, ophthalmic lesions, hematology, gross pathology, or histopathology. Based on clinical chemistry and organ weight changes, it appears that the liver, kidney, and adrenal glands were target organs for systemic toxicity to TCP in this study, although this was not correlated with histopathology lesions. It was concluded that 240 mg/kg/day represents a lowest observed adverse effect level (LOAEL), although the toxic effects were minimal. The no observed adverse effect level (NOAEL) for subchronic exposure to TCP by the oral route was 80 mg/kg per day. [ABSTRACT FROM PUBLISHER]

A method is described for the determination of dimetridazole (1,2-dimethyl-5-nitroimidazole) in pig tissues. The final estimation is made by direct current polarography. [ABSTRACT FROM AUTHOR]

Residues of dimetridazole (1,2-dimethyl-5-nitroimidazole) in the tissues of pigs after administration of the drug are reported. Three dosing regimes were examined, administration of 0.05% dimetridazole in the feed for a period of 1 month, administration of 0.05% dimetridazole in the feed for a period of 2 months, and administration of 0.05% dimetridazole in the drinking water for a period of 1 week. The maximum drug level found was 6.9 μg/ml in the plasma of a pig after one week's medication with dimetridazole in the drinking water. Depletion of the drug was rapid and 48 h after the withdrawal of medication tissue levels of the drug were invariably less than 0.1 μg/g. [ABSTRACT FROM AUTHOR]

Recent advances in the technology associated with digital radiography have created new opportunities for biomedical research applications. Here we evaluated the use of thoracic radiography as a noninvasive refinement methodology for the cynomologus macaque (Macaca fascicularis) model of H1N1 infection. Thoracic radiographic evaluations of macaques infected with any of 3 strains of emerging H1N1 swine-associated influenza virus isolated during the recent pandemic were compared with those of macaques infected with the currently circulating Kawasaki strain of H1N1 influenza. Ventrodorsal, right, and left lateral thoracic radiographs were obtained at days 0, 1, 6, 8, 11, and 14 after infection. A board-certified veterinary radiologist who was blinded to the study design evaluated the images. Numeric scores of extent and severity of lung involvement assigned to each radiograph were compared and demonstrated a significant and substantial difference among groups. The radiographic evaluation allowed for noninvasive assessment of lung involvement, disease onset, progression, and resolution of radiographic changes associated with H1N1 influenza infection.