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Skin cancer has long been associated with industrial and environmental exposure to individual chemical compounds, complex chemical mixtures, X-irradiation and UV-irradiation. Skin carcinogenesis in animal models has been used as a toxicity assay and to study mechanisms of neoplastic progression. Using a mouse-skin carcinogenesis model, we conducted assays(More)
This study assessed the relationship between nitrogen dioxide inhalation and the development of pulmonary emphysema and investigated how the severity of preexisting emphysema brought about by protease (elastase) instillation into the lung may be augmented by a subchronic exposure to a relatively high concentration of nitrogen dioxide. Lungs of adult(More)
Min-U-Sil5, a form of alpha quartz, has been shown to induce peripheral lung tumors in rats exposed to the dust by inhalation. The animals were exposed to a nominal particle concentration of 12.4 mg/m3 for 8 hr/day, 4 days/week, for 2 years. The induced tumors were large and peripheral, and, when examined by electron microscopy, were found to be composed(More)
The sizes of the alveolar macrophage (AM) and interstitial macrophage (IM) populations in the lungs of adult Fischer-344 rats were determined during steady state. AM labeled with opsonized erythrocytes during an in situ phagocytic assay were lavaged from excised lungs. The lungs were then dispersed into single-cell suspensions with collagenase and(More)
Language, speech, cognitive-associated communication deficits, and dysphagia are common following acquired brain injury (stroke, traumatic brain injury, and others). Treatment of these disorders can be divided into restorative, compensatory, and supportive approaches. Although therapy must be individualized for each person, components of all three(More)
  • L M Holland
  • 1990
The International Agency for Research in Cancer (IARC) has recently stated that crystalline silica should be regarded as a potential carcinogen. The IARC bases this statement on a finding that there is limited evidence of carcinogenicity in humans and sufficient evidence for carcinogenicity in animals. Recent laboratory animal experiments demonstrating a(More)
Seven rhesus monkeys (14 eyes) were exposed to 1064-nanometer radiation in single pulses of 25 to 35 picoseconds fromn a mode-locked Nd: YA G laser. Threshold injury resulted from single pulses with a mnean energy of 13 +/- 3 mnicrojoules. Electron microscopy of the retina revealed that damnage was highly localized in the photoreceptor and pigmented(More)
Classic mouse skin-painting assays of such highly-complex mixtures as petroleums and synthetic fuels may lead to severe local cytotoxic effects that can alter tumorigenesis. This effect can be particularly disruptive in dose-response studies where a wide range of doses is employed. The experiments described here illustrate that frequency of exposure may be(More)