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Biomedical subjects

J E Gallagher

Publications and source records attributed to J E Gallagher.

At least 55 records · Page 3Linked to original sources
PubMed1981

Lesions in the small intestine of newborn pigs inoculated with porcine, feline, and canine coronaviruses.

The infectivity and pathogenicity to newborn pigs of antigenically related coronaviruses from pigs (transmissible gastroenteritis virus; TGEV), cats (feline infectious peritonitis virus; FIPV), and dogs (canine gastroenteritis virus; CGEV) were studied by light, scanning electron, and immunofluorescence microscopy. Hysterectomy-derived, 12-hour-old pigs were orally given tissue culture or frozen preparations of 6 coronavirus strains (3 porcine, 2 feline, and 1 canine). The pigs were killed at regular intervals between 24 and 144 hours after exposure. Virulent TGEV and virulent FIPV produced necrosis of villous epithelium, resulting in villous atrophy in the jejunum and the ileum. Similar, but less extensive and severe lesions, were produced by the 4 other viruses. Coronaviral antigens were identified by immunofluorescence in villous epithelial cells of pigs that had been inoculated with virulent TGEV, attenuated TGEV, virulent FIPV, and tissue culture-adapted FIPV. In contrast, coronaviral antigens were not induced by the small plaque variant TGEV and virulent CGEV in the villous epithelium, but rather in cells of the lamina propria and crypt epithelium.

Animals↗
PubMed1981

Effects of Mycoplasma hyopneumoniae and M. hyorhinis on ependymal cells of the porcine lateral ventricles as observed by scanning and transmission electron microscopy.

Porcine lateral ventricular ependymal cells were used to study the effects of infection with Mycoplasma hyopneumoniae and M. hyorhinis on the central nervous system (CNS) of pigs. After cerebral or cerebrospinal inoculation, cellular sequential changes were observed by scanning (SEM) and transmission (TEM) electron microscopy. Strains of M. hyopneumoniae and M. hyorhinis were recovered from infected tissues at 1 and 3 weeks postinoculation. The mycoplasmas caused lesions of ependymal cells. Degenerative processes ranged from loss of microvilli and cilia to membrane breakdown and invasion of cells. The results suggest that mycoplasmas cause ependymal cytopathological effects similar to those that they cause in ciliated epithelial cells of the trachea and lung. Both M. hyopneumoniae and M. hyorhinis may be involved in the pathogenesis of certain ill-defined CNS disorders in swine. The potential value of using both SEM and TEM to observe the effects of mycoplasmal infection on ependymal cells of the porcine CNS was demonstrated.

Animals↗
PubMed1979

Simplified preparation of mycoplasmas, an acholeplasma, and a spiroplasma for scanning electron microscopy.

A simple, effective procedure was developed for scanning electron microscopic examination of mycoplasmas and similar organisms. Cultivation of several mycoplasmal species, an acholeplasma, and a spiroplasma in broth media in Leighton tubes with cover slips resulted in attachment of the organisms to the cover slips. The attached cells were easily processed for either scanning electron microscopy or light microscopy. By eliminating the need for centrifugation, which was used in previously described techniques, physical stress on the cell is minimized. The effects of different preparative procedures on the morphology of Mycoplasma gallisepticum are described.

Acholeplasma laidlawii↗
PubMed1978

Preparation and long-term cultivation of porcine tracheal and lung organ cultures by alternate exposure to gaseous and liquid medium phases.

Conventional methods of organ culture have proved unsatisfactory for mammalian lung because of the rapid collapse of the tissue and the loss of its normal structure. In an effort to circumvent this problem and to provide a means for visualizing the cellular relationships throughout the culture period, respiratory organs consisting of trachea and lungs of fetal or hysterectomy-derived 1- to 4-week-old pigs were embedded in warm 3% Noble agar in phosphate buffer silicone solution and cooled to firmness. By use of a described cutting device, the respective organs were sliced into thin, 0.5- to 1.0-mm tracheal ring or lung explants. These organ sections then were cultured by exposure to alternate gaseous and liquid-medium phases by rotation (12 rev per hr) in sealed Leighton tubes fitted in a described rotator. In short-,erm culture experiments, explants were best maintained in a culture-support medium containing Eagle's minimal essential medium, 20% fetal bovine serum, 0.5% lactalbumin hydrolysate, and other supplements in a pH range of 6.5 to 8.2, and a NaCl concentration of 0.1 M or less. By bright-field and scanning-electron microscopy, tracheal ring and lung explant cultures incubated for 2 months showed intact, uniform and active ciliated epithelial surfaces which compared favorably with those of fresh preparations. The lung cultures showed alveoli that remained expanded, and the cellular integrity of the tissues remained normal in appearance. This new method provides respiratory organs as continuous records with exceptional cellular clarity and readily available for histological processing. The organ cultures lend themselves well to pathogenesis studies in which subtle cellualr changes or a sequence of changes induced in pulmonary tissues are difficult to observe in the host.

Animals↗
PubMed1978

Cytopathogenicity of Mycoplasma hyopneumoniae in porcine tracheal ring and lung explant organ cultures alone and in combination with monolayer cultures of fetal lung fibroblasts.

Porcine tracheal rings and lung explants alone and in combination with monolayer cultures of porcine lung fibroblasts (PLF) were separately inoculated with virulent strains of Mycoplasma hyopneumoniae and incubated at various times. The preparations were observed by bright-field, phase-contrast, and scanning electron microscopy. In PLF cultures, the strains at initial concentrations of 10(1.3) colony-forming units/ml increased within 3 days to 10(6) colony-forming units/ml, showed progressive clustering on the cells, and caused some sloughing. Introduction of a tracheal ring or lung explant into these mycoplasma-infected PLF cultures caused the explant to lose its epithelial ciliary motility. Eventually parts or whole cells of the respective ciliated epithelium were lost. Without infected PLF monolayers, the explants inoculated with M. hyopneumoniae were less susceptible to infection. When uninfected explants were incubated for 18 days or kept in stock for 2 months, they did not show the above changes. With 5 h postinoculation, M. hyopneumoniae cultures became intimately associated with the PLF culture, but when epithelial cell sloughing occurred, the mycoplasmal cells became dependent on the introduction of a fresh PLF monolayer or a tracheal or lung explant for survival.

Culture Techniques↗
PubMed1978

A method for locating individual leukocytes for comparative study by light and scanning electron microscopy.

A method is presented for locating individual leukocytes and platelets in Wright's stained blood films for comparative study by light and scanning electron microscopy. The individual cells in the blood films were photographed and the field was circled with a diamond marker objective. The slide was scored and broken; pieces of the stained slide containing the numbered circles were fixed (with conductive cement) to a metal stub, air dried, and coated with metallic gold. The metal stub was placed in a scanning electron microscope, and the marked cells were readily located and photographed so that their three-dimensional surface morphology could be compared with the morphologic features of stained cells in the blood film photographed with the light microscope. Characteristics of individual cell types are discussed.

Animals↗
PubMed1977

Ureaplasmal epithelial lesions related to ammonia.

The pathological effects of ureaplasmas on oviductal epithelium (ciliostasis and deciliation) were duplicated by adding ammonia to the medium as ammonium sulfate or by adding jack bean urease, which hydrolyzed the urea in the medium.

Ammonia↗
PubMed1976

Growth and effects of ureaplasmas (T mycoplasmas) in bovine oviductal organ cultures.

Ureaplasmas isolated from the human genital tract and from the genital and respiratory tracts of cattle were grown in association with organ cultures of bovine oviduct (uterine tube). All strains of unreaplasmas multiplied in organ cultures, stopped ciliary activity, and caused histological lesions. Most strains grew well, and 10(8) to 10(9) color-changing units were determined 18 to 144 h after inoculation. Twenty-four to 144 h after inoculation with unreaplasmas, ciliostasis was complete. Ciliostasis was also caused by additions of nonviable cultures at pH 8.8 (or adjusted to 7.4) or washed disrupted cells (100 mug of protein/ml); it occurred in 48 to 96 h. The cilia-stopping effect of nonviable cultures was diminished by heating (56 C for 30 min) and was abolished by boiling. When added to fresh medium in amounts exceeding 25%, nonviable unreaplasmal cultures completely inhibited ureaplasmal growth. By light, scanning, and transmission electron microscopy, cilia-stopping effect was correlated with collapse and sloughing of the cilia (the initial lesion was "bent" cilia), with bulging and vacuolization of secretory and ciliated cells, and finally with disorganization of the epithelium, necrosis, and desquamation.

Animals↗
PubMed1975

Scanning electron microscopy of the bovine, equine, porcine, and caprine uterine tube (oviduct).

The luminal surface topography of bovine, equine, porcine, and caprine uterine tubes was studied by scanning electron microscopy. The main types of epithelial cells were secretory and ciliated. Both types were more active during estrus. Cilia were observed in both the infundibular and the ampular parts of the uterine tube, but ciliated cells were more numerous than secretory cells on the surface of the fimbriae. Sperm were observed in the ampulla of the uterine tube of the cow 2 hours after artificial insemination.

Animals↗
PubMed1975

Effects of Mycoplasma spp, Trichomonas fetus, and Campylobacter fetus on ciliary activity of bovine uterine tube organ cultures.

Microscopic observations were made of sections of normal bovine uterine tube (oviduct) and fimbriae maintained in vitro and exposed to agents known to localize in the bovine genital tract, i.e., mycoplasma, Trichomonas fetus, and Campylobacter fetus (Vibrio fetus). Only C fetus stopped ciliary activity. Scanning electron microscopy (SEM) revealed loss of most cilia. Sterile filtrate of C fetus culture had no effect.

Animals↗