Histomorphology and ultrastructure of spontaneous pulmonary neoplasms in strain A mice.

The microscopic and ultrastructural characteristics of spontaneous pulmonary neoplasms in strain A (strA) mice are described. Fifty-one spontaneous lung tumors were identified in 34 out of 57, 11-23-month-old male strA/Hen mice. Grossly, all tumors appeared as yellow-white, discrete nodules ranging in size from 1.

Epididymal interstitial (Leydig) cell tumors in B6C3F1 mice.

Six primary interstitial cell tumors of the epididymis were identified from 46,752 male B6C3F1 mice used in chronic toxicity and carcinogenicity studies. Five of the tumors occurred at the end of 2-year studies; none were attributed to treatment. None of the mice with epididymal tumors had a primary testicular tumor.

Classification and morphometric quantitation of insoluble materials from the lungs of patients with alveolar proteinosis.

Insoluble materials isolated by bronchoalveolar lavage from the lungs of four patients with alveolar proteinosis were examined under the electron microscope, categorized according to ultrastructural criteria, and quantitated using morphometric procedures. The major component of the insoluble accumulations was the tubular myelinlike multilamellated structure that accounted for 42.6 +/- 12.

Ultrastructural changes in the nasal mucosa of Fischer 344 rats and B6C3F1 mice following an acute exposure to methyl isocyanate.

Male rats and male mice received a single 2-hr exposure to 0 (control), 10, or 30 ppm of methyl isocyanate and were sacrificed after 1, 3, 14, or 90 days to assess the ultrastructural changes in the nasal mucosa by transmission electron microscopy. One day after exposure to methyl isocyanate, there were widespread areas of necrosis and degeneration of the respiratory and olfactory epithelium of rats and mice in the 10 ppm and 30 ppm groups. Qualitatively the ultrastructural findings were similar for both exposure groups and species.

Dissolution and reassembly of tubular myelin-like multilamellated structures from the lungs of patients with pulmonary alveolar proteinosis.

Tubular myelin-like multilamellated structures that accumulate in the alveoli of patients with pulmonary alveolar proteinosis are a characteristic manifestation of the disease. These multilamellated structures appear to be an abnormal form of tubular myelin consisting of phospholipid bilayers separated from each other by amorphous proteinaceous material. Treatment of tubular myelin-like multilamellated structures with 10% N-acetylcysteine in aqueous solution resulted in the dissolution and extraction of the intermembranous amorphous material.

Acceptability of Bacon Stored Six Weeks at 4 or -23°C.

Bacon was obtained from production lines of two local processing plants, H and M. The slices from 8 bellies from each plant were sequentially rearranged to form composite portions representative of each belly; these were analyzed for moisture-phase NaCl and for acceptability by a panel of judges using a 9-point hedonic scale. Samples were tasted shortly after processing and again after 6 weeks of storage at 4 or -23°C.

Multilamelled structures from the lungs of patients with pulmonary alveolar proteinosis.

Multilamellated structures (MS), which accumulate in the lungs of patients with pulmonary alveolar proteinosis, were examined under the electron microscope. MS, in general, consisted of alternating light and dark lamellae arranged concentrically about membranous vesicles or electron-dense bodies. The darker osmiophilic lamellae consisted of trilaminar membranes 80 to 100 A thick, and the lighter lamellae, which varied from 150 to 300 A in width, appeared amorphous.

Peritoneal macrophage alterations caused by naturally occurring mouse hepatitis virus.

During routine harvest of murine resident peritoneal cells for macrophage function assays the authors recently noted that mice showed a 3-4-fold spontaneous increase in number of peritoneal cells within 1 week of being placed in one of their animal rooms. While the mice appeared clinically normal, the collected macrophages had highly convoluted membranes, showed enhanced spontaneous tumor cell killing, and showed increased erythrophagocytosis. Histopathologic findings included mild peritonitis and occasional foci of individual hepatocyte necrosis.

Composition of bronchoalveolar lavage effluents from patients with pulmonary alveolar proteinosis.

The lungs of patients with pulmonary alveolar proteinosis were lavaged with saline. The lavage effluents were examined for the presence of unusual components which might be considered characteristic of the disease. Soluble proteins were resolved by electrophoresis on polyacrylamide linear gradient (2.

Intracytoplasmic hyaline globules in the adrenal medulla of laboratory animals.

Intracytoplasmic hyaline globules were found frequently in chromaffin cells of the adrenal medulla from several species of laboratory animals that died from various causes. The globules stained intensely red with PAS, were weakly acid-fast, did not stain with oil-red O and showed bright yellow autofluorescence. Ultrastructurally, they were finely granular, round to oval, intensely osmiophilic and were surrounded by an intimately bound trilaminar membrane.

The fine structure of intracranial neoplasms induced by the inoculation of avian sarcoma virus in neonatal and adult rats.

Groups of F-344 rats were inoculated with the Bratislava-77 strain of avian sarcoma virus (B-77 ASV) within 24 hours of birth, at 9 days of age, or between 97 and 119 days of age. Intracranial tumors developed in each age group. Multiple tumors with mixed histologic patterns developed in rats inoculated at 1 or 9 days of age.

Effects of vinyl chloride exposures to rats pretreated with phenobarbital.

Male rats were exposed to 10 consecutive days, 6 hr/day, to vinyl chloride vapors at an average concentration of 13,500 ppm. The exposed rats were divided into three groups of eight rats each: one group was pretreated with 3-methylcholanthrene, one group was pretreated with phenobarbital, and the third group received no treatment. Half the animals in each group were sacrificed 18 hr after the last exposure and half were sacrificed 4 days later.