Ultrastructure of proliferative ileitis in hamsters (Mesocricetus auratus)

The ileum of affected hamsters bore microvilli which were much shorter, less regularly arranged and less densely packed than those from control animals. Organelle derangements such as atrophy of mitochondria, degranulation and dilated cisterna of endoplasmic reticulum, were observed. Some hyperplastic epithelial cells contained multiple intracytoplasmic inclusion bodies and amyloid deposits were present extracellularly.

Stimulation of DNA synthesis in the lungs of hamsters exposed intermittently to nitrogen dioxide

Stimulation of [3H] thymidine incorporation in the lungs of hamsters exposed singly and repeatedly to 10 ppm NO2 was studied. Within 24 hr of the first exposure to NO2, the response was characterized by a marked increase in [3H] thymidine labeling in the bronchi, bronchioles, and alveolar ducts, but not in the trachea or the peripheral alveoli. If, after the first NO2 exposure, subsequent exposures were repeated daily, no further stimulation of [3H] thymidine incorporation was observed in any part of the respiratory tract. However, if the interval between the first and subsequent exposures was 2-3 days rather than 1 day, stimulation of [3H] thymidine incorporation was observed in the bronchi, bronchioles, and alveolar ducts for up to 21 NO2 exposures. A significantly greater increase in [3H] thymidine incorporation was observed when the interval between subsequent exposures was extended to 7 days. However, no repeated exposure, whether at 2-3 or 7 day intervals, was as effective as the first NO2 exposure in stimulating incorporation of [3H] thymidine.

Malignant melanoma metastatic to the lung in a pet hamster

A 2 year old pet male hamster died with spontaneously occurring ocular melanoma. Metastasis occurred in the lung.

Ultrastrutural studies of vascular and muscular changes in ascorbic acid deficient guinea-pigs

Disorganization of muscle structures such as fragmentation of myofilaments with a loss of contrast in the Z bands, swelling of mitochondria and glycogenic infiltration, was seen in ascorbic acid deficient guinea-pigs. Vacuolar degeneration of external and internal endothelial cell membranes with accompanying dystrophic changes of the surrounding muscle and lack of collagen formation were consistent findings. Chondroblasts showed a marked dissolution of the matrix vesicle and a lack of hyaline droplets.

Immunological injury in "shipping fever" pneumonia of cattle

Electron opaque deposits were found on the alveolar capillary walls, luminia of alveolar capillaries, subendothelium and interstitium of four out of 10 Holstein dairy cattle with past shipping histories. The deposits were positive for anti-IgG bovine immunoglobulin by fluorescent antibody technique. Evidence is presented that antigen antibody complexes may play an important role in bovine respiratory diseases.

Scanning electron microscopic studies of simian lung mites (Pneumonyssus santos-diasi, Zumpt and Till, 1954)

Scanning electron microscopy was used to study general morphological features of female Pneumonyssus santos-diasi, the most common lung mite found in the baboon (Papio cynocephalus), and its effect on host tissues. The technique provides an excellent three-dimensional correlation with light microscopic taxonomic identification and brings further insight to a detailed host parasite relationship.

An epizootic outbreak of ringworm in a guinea-pig colony caused by Trichophyton mentagrophytes

The disease was characterized by loss of hair, initially occurring at the tip of the nose and spreading throughout the body. Lesions appeared as circular, scaley alopecia with occasional scarring. Although spread of the infection in the colony was random, the most severe infection occurred in an inbred line with light coat colour. The unusually high temperature and humidity, and the open type of outdoor management, appear to have contributed to the high incidence and severity of infection. Electron microscopic observation indicated that the organism multiplied in the keratin layer of the skin. The hyphae as well as chlamydospores were readily demonstrable by electron microscopy.

A review of 105 necropsies in captive baboons (Papio cynocephalus)

In contrast to the findings in newly caught babboons in Africa, the leading cause of death in captivity in America was a pneumonia and enteritis complex. Bacterial species such as Proteus morgani, Proteus mirabilis, Clostridium sp., Pseudomonas paracolon, pathogenic Escherichia coli and cocci have been isolated in association with a pneumoenteric syndrome of 35 newborn baboons, including neonates. The majority of these animals died with pulmonary factors such as anoxia and pneumonia.

Pathology of pulmonary acariasis in Baboons (Papio sp.)

Pulmonary acariasis is one of the important and more frequently observed spontaneously occurring diseases in African baboons (Papio sp.). It has been found more frequently in baboons in their native habitat than in those in captivity. Prevalence also varies with the sites of captivity. Histopathologic changes occurring in the lungs due to infection with Pneumonyssus santos diasi and P. mossambicensis are described.