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Biomedical subjects

I K Barker

Publications and source records attributed to I K Barker.

At least 73 records · Page 4Linked to original sources
PubMed1988

The effect of certain topical medications on healing of cutaneous wounds in the common garter snake (Thamnophis sirtalis).

The effects of four topical medications on the rate and character of healing of cutaneous wounds were studied in six common garter snakes (Thamnophis sirtalis) held at an ambient temperature of 30 degrees C. Two sets of five 6 to 8 mm round excisional wounds, four test and one control site in each set, were created on the dorsolateral body wall of each snake. Wounds were examined daily and treated for ten days, then the snakes were killed and sections of all wounds were examined by light microscopy. Composite scores, derived by ranking each treatment group in relation to the control group (control score = 0) for each of 22 characteristics associated with wound healing, were used to compare the overall effects of each treatment. Statistical comparisons were made between groups for 20 characteristics. Wounds treated with a polyurethane film merited a score of +12 and had significantly more advanced healing than untreated controls for three characteristics. Wounds treated with an ointment containing scarlet red scored +6 but healing was not significantly greater than controls. Wounds treated with an antibacterial spray powder and an antibacterial ointment healed more slowly than controls and had scores of -6 and -12 respectively.

Administration, Topical↗
PubMed1987

Epithelial and pillar cell replacement in gills of juvenile trout, Salmo gairdneri Richardson.

Young rainbow trout, Salmo gairdneri (Richardson) were injected intraperitoneally with tritiated thymidine, and killed at intervals between 2 hr and 16 days after inoculation. Labelled epithelial cells were first detected autoradiographically along the base of gill lamellae. Epithelial cells proliferated here and then migrated toward the tips of the lamellae. Uniform labelling along the length of the filaments at the base of lamellae indicated that cells were dividing at a constant rate. Transverse sections of filaments showed that epithelial proliferation was also uniform across the base of the lamellae. The interior of the lamellae often had labelled pillar cells, indicating that these cells also divide. The high intensity of the label in animals killed 16 days after inoculation with tritiated thymidine suggests that division probably occurs slowly, less than once every 16 days.

Animals↗
PubMed1987

An outbreak of schistosomiasis in Atlantic brant geese, Branta bernicla hrota.

A heavy infection with schistosomes of the genera Trichobilharzia and Dendritobilharzia was considered the cause of 90% mortality in a group of 40 wild-caught Atlantic brant geese (Branta bernicla hrota) that were maintained in captivity on a fresh-water pond in Aurora, Ontario. Numerous adult worms and eggs were disseminated in many organs throughout the body of all birds examined. The main pathological findings, attributed to both eggs and adults, included emaciation, thrombosis of the caudal mesenteric vein and its branches, fibrinohemorrhagic colitis, and in some birds, heptomegaly. Translocation of brant geese from their natural marine environment to a fresh-water pond may have caused them to be exposed to parasites which they would not normally encounter.

Animals↗
PubMed1986

Tyzzer's disease as a complication of canine distemper in a raccoon.

Intercurrent canine distemper and Tyzzer's disease were diagnosed in a mature raccoon (Procyon lotor) submitted for necropsy. Clinical, gross and microscopic findings characteristic of canine distemper virus (CDV), included ataxia, dyspnea, suppurative conjunctivitis, interstitial pneumonitis and generalized lymphocytolysis. Inclusion bodies typical of CDV infection were present in many epithelial tissues. Acute multifocal hepatic necrosis and acute segmental necrotizing enteritis were attributed to the presence of Bacillus piliformis organisms in these lesions, confirmed by special stains and electron microscopy. This is apparently the first reported case of Tyzzer's disease in a raccoon.

Animals↗
PubMed1985

Klossiella (Apicomplexa, Klossiellidae) in petaurid and macropodid marsupials in Australia.

Six new species of Klossiella are described in the kidneys of Australian marsupials: Klossiella rufogrisei in Bennett's Wallaby, Macropus rufogriseus; Klossiella rufi in the Red Kangaroo, Macropus rufus; Klossiella thylogale in the Red-Bellied or Tasmanian Pademelon, Thylogale billardierii; Klossiella beveridgei in the Spectacled Hare-Wallaby, Lagorchestes conspicillatus; Klossiella bettongiae in the Tasmanian Bettong, Bettongia gaimardi; and Klossiella schoinobatis in the petaurid Greater Glider, Petauroides volans. It is concluded that the genus Klossiella has radiated widely among Australian marsupials, and that since it is present in American marsupials, it may have an ancient association with the subclass.

Animals↗
PubMed1984

Endogenous development and pathogenicity of Eimeria angusta in the ruffed grouse, Bonasa umbellus.

Oocysts of Eimeria angusta were recovered from the cecum of a captive ruffed grouse which died of coccidial typhlitis. Five experimental passages were made in grouse over a 2-yr period. Prepatent period was 6.5-7.0 days; sporulation time at 22 C was 54-60 hr. Endogenous stages were not found in grouse killed 1 and 2 days after inoculation (DAI). A few immature schizonts were in cecal epithelium 4 DAI. Developing and mature schizonts, and undifferentiated gamonts were in cecal epithelium 5 DAI. Developing micro- and macrogamonts, but no oocysts, were present 6.5 DAI. Fibrinohemorrhagic typhlitis, associated with large numbers of gamonts and oocysts in the epithelium, was found 9 DAI. Cecal glands were hypertrophic and there was a heavy mixed inflammatory cell reaction. Diarrhea, depression and reduced feed intake occurred 7-10 DAI with most severe signs and greatest oocyst passage 8 or 9 DAI. Most infected birds lost weight 5-8 or 9 DAI, but none died.

Animals↗
PubMed1983

Morphogenesis of Trichostrongylus rugatus and distribution during development in sheep.

Morphogenesis of Trichostrongylus rugatus was examined in 16 sheep experimentally-infected with 120 000 third-stage larvae and killed 2, 4, 6, 8, 10, 12, 16 and 20 days later (DAI). Third stage larvae moulted between Days 4 and 6, and fourth stage larvae moulted on Day 10 after infection. Four sheep first passed eggs in the faeces between Days 16 and 18 after infection. Rate of growth of larvae was constant between 2 and 10 DAI followed by a period of rapid growth from 10 to 16 DAI. Major features of larval development are described. Nematodes were largely restricted to the first 6 m of gut with 71% of worms occurring in the first 3 m.

Abomasum↗
PubMed1983

Development of villus atrophy in the small intestine of sheep infected with Trichostrongylus rugatus.

Pairs of sheep infected with 120 000 larvae of Trichostrongylus rugatus were killed at intervals from 2 to 56 days after infection (DAI). Worms were located in tunnels in the epithelium of villi or upper intestinal crypts at all stages of development. Villus atrophy developed progressively until 16 DAI, when surface microtopography, characterised by subtotal villus atrophy, stabilised. Most severe lesions were in the first 3 m of small intestine where the density of nematodes was highest. Discontinuities in the epithelium and effusion of inflammatory cells and tissue fluids into the lumen were rare. No effects of infection on body-weight gain, appetite or serum total protein and albumin were evident in the first 20 days of infection. However, it was concluded that T. rugatus fundamentally resembled T. colubriformis and T. vitrinus in the response it elicited in the intestine of sheep, and must be considered potentially pathogenic.

Animals↗
PubMed1983

Four cases of Hodgkin's disease in striped skunks (Mephitis mephitis).

Twelve of 152 striped skunks (Mephitis mephitis) necropsied at the Ontario Veterinary College between 1970 and 1980 had neoplasms. Tumors occurred in one of 86 wild skunks, and 11 of 66 captive skunks. Captive skunks were primarily from one source and were older animals. Tumors in four skunks resembled those found in Hodgkin's disease of man. This diagnosis was based on the presence of Sternberg-Reed cells, the cellular pattern, and the malignant behavior of the neoplasms. In two of these skunks, a second neoplasm also was present. Other tumors diagnosed included pulmonary adenocarcinoma, pulmonary adenomatosis, undifferentiated adenocarcinoma, renal adenocarcinoma, thyroid adenoma, interstitial cell tumor, pheochromocytoma, pinealoma, squamous cell carcinoma, and spindle cell sarcoma.

Animal Diseases↗
PubMed1983

Response of mink, skunk, red fox and raccoon to inoculation with mink virus enteritis, feline panleukopenia and canine parvovirus and prevalence of antibody to parvovirus in wild carnivores in Ontario.

Mink virus enteritis, feline panleukopenia and canine parvovirus-2 were inoculated separately into groups of raccoon, mink, red fox and striped skunk. Raccoons were highly susceptible to mink virus enteritis and feline panleukopenia, with animals developing clinical illness, and several dying within six to ten days of inoculation with lesions typical of parvovirus infection. Both viruses were shed in high titre in the feces of infected raccoons, and high antibody titres were stimulated. Raccoons inoculated with canine parvovirus-2 showed no signs; shedding of virus was sporadic though moderate titres of antibody developed. Mink inoculated with mink virus enteritis and feline panleukopenia developed signs and lesions of early parvovirus infection. No signs or significant lesions followed canine parvovirus-2 inoculation. Shedding of virus was heavy (mink virus enteritis) or sporadic (feline panleukopenia and canine parvovirus-2), though good serological responses were elicited to all three viruses. Red fox showed no signs of infection, shed all three viruses only sporadically, and the serological response was strong only to feline panleukopenia. Skunks developed low antibody titres, but no signs, and did not shed virus. Antibody to parvovirus was found in 79.2% of 144 wild red foxes; 22.3% of 112 wild raccoons; 1.3% of 157 wild skunks and 6/7 coyotes in southern Ontario. The likely significance of these viruses to wild and captive individuals and populations of these carnivores is discussed.

Animal Population Groups↗
PubMed1982

Mass mortality of harbor seals: pneumonia associated with influenza A virus.

More than 400 harbor seals, most of them immature, died along the New England coast between December 1979 and October 1980 of acute pneumonia associated with influenza virus, A/Seal/Mass/1/180 (H7N7). The virus has avian characteristics, replicates principally in mammals, and causes mild respiratory disease in experimentally infected seals. Concurrent infection with a previously undescribed mycoplasma or adverse environmental conditions may have triggered the epizootic. The similarities between this epizootic and other seal mortalities in the past suggest that these events may be linked by common biological and environmental factors.

Animals↗
PubMed1982

Spontaneous gastric squamous cell carcinomas and other neoplasms in Greenland collared lemmings (Dicrostonyx groenlandicus).

Malignant neoplasms were present in 39/66 Dicrostonyx groenlandicus of varying ages, examined from a laboratory colony. The presence of multiple neoplasms in some resulted in an overall average of 1.15 tumors/affected animal. Gastric squamous papillomas were present in nine, and locally invasive or metastatic gastric squamous cell carcinomas in a further 36 animals. Three mammary adenocarcinomas, one pancreatic islet cell tumor, one probable pancreatic adenocarcinoma and one adrenal cortical adenoma were also seen in lemmings with gastric tumors. Two others had mammary adenocarcinoma alone, and one animal had bilateral Harderian gland adenocarcinoma. Lesions resembling glomerulonephrosis of rats were seen in 23/51 animals whose kidneys were examined. These findings were not considered artefacts of captivity since concurrent gastric squamous cell carcinoma, mammary adenocarcinoma and glomerulonephrosis were present in the single animal examined directly from the wild at Eskimo Point, Northwest Territories.

Adenocarcinoma↗
PubMed1981

Cytomegalovirus infection of the prostate in the dasyurid marsupials, Phascogale tapoatafa and Antechinus stuartii.

Infection by a herpesvirus producing cytomegalic disease in the prostate was demonstrated in the dasyurid marsupials, Phascogale tapoatafa and Antechinus stuartii. The prevalence of lesions among the latter was highest in mature animals during breeding, when the animals are known to be under stress, and in animals treated daily with high levels of exogenous corticosteroid. Occasional cytomegaly was observed in the kidneys of some A. stuartii and may represent a site of latent infection. Virus particles of herpes type were demonstrated by electron microscopy in the nucleus and cytoplasm of infected prostatic cells. It is suggested that the infection may be venereal.

Animals↗
PubMed1981

Campylobacter jejuni colitis in gnotobiotic dogs.

Campylobacter jejuni of human and canine origin was inoculated orally into six gnotobiotically reared Beagle puppies and reactions were compared with two controls. Inoculated dogs developed transient lassitude, inappetence, mild diarrhea and tenesmus during the period 36-72 hours after inoculation. Pairs of dogs killed 43 hours, and five and seven days after inoculation had lesions limited to typhlitis and colitis. Congestion of colonic mucosa, associated loss of goblet cells, attenuation and exfoliation of surface epithelium with microerosions, hypertrophy of glands and neutrophil infiltration of lamina propria were seen during the acute phase. Less severe surface and inflammatory lesions were evident at five and seven days, with hyperplasia of the proliferative compartment in mucosal glands. Campylobacter established at over 10(10) organisms per gram of colonic content but did not invade the mucosa. It was concluded that the gnotobiotic dog may be a suitable model for investigation of the pathogenesis of Campylobacter colitis.

Animals↗
PubMed1980

Influenza viruses isolated from waterfowl in southern Ontario, 1976-1978.

From 1976 to 1978, samples were collected from 720 ducks, 100 terns, and 50 gulls for attempted isolation of influenza viruses. Influenza viruses were isolated from 32 of the ducks samples: 10.2% of those sampled in 1976, 4.8% in 1977, and 2.4% in 1978. At least six different hemagglutination and seven neuraminidases were identified in the viruses isolated, in 14 different combinations.

Animals↗