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Biomedical subjects

J M Gaskin

Publications and source records attributed to J M Gaskin.

At least 55 records · Page 3Linked to original sources
PubMed1979

Fetal mortality and malformations associated with experimental infections of western equine encephalomyelitis vaccine virus in rhesus monkeys (Macaca mulatta).

Pregnant Rhesus monkeys were infected via installation of Western Equine Encephalomyelitis (WEE) vaccine virus into the amniotic sacs at 50 and 80 days gestation to determine if the resulting infections would produce fetal mortality or fetal malformations, particularly within the central nervous system. Of those receiving virus at 50 days gestation, 13 of 18 fetuses were aborted or dead in utero at time of Caesarean section; 2 of 18 were malformed (hydrocephalus and polyarthrosis); and 3 of 18 were anatomically normal. Of those receiving virus at 80 days gestation four of eight fetuses were aborted or dead in utero at time of Caesarean section, one of eight was malformed (hydrocephalus) and three of eight were anatomically normal. Three of three controls receiving neutralized virus at each gestational age were anatomically normal. Fetal WEE vaccine virus infection significantly increased fetal mortality and resulted in a significant incidence of fetal malformations.

Animals↗
PubMed1978

Cyclic thrombocytopenia induced by a Rickettsia-like agent in dogs.

Hematologic manifestations and the ultrastructure of a platelet-specific microorganism isolated from a dog in Florida were studied. The agent was readily transmitted experimentally to adult dogs by intravenous inoculation with infected blood. Parasitemias and concomitant thrombocytopenias were cyclic in that both recurred within relatively constant periods of one to two weeks following experimental infections. Hemorrhage was not a manifestation of the disease even though thrombocytopenias were severe. Microorganisms were visualized by light and electron microscopy. They were observed only in platelets and were composed of single or multiple subunits (morula forms). The microorganisms were ultrastructurally very similar to those reported in Ehrlichia canis infections of dogs and Anaplasma marginale infections of cattle. Microorganisms were surrounded by single membranes which more or less conformed to the external surfaces of subunits that were surrounded by double membranes. From electron microscopic studies, it is suggested that these organisms be classified in the order Rickettsiales.

Alphaproteobacteria↗
PubMed1978

Feline myeloproliferative disease. Changing manifestations in the peripheral blood.

A 4 1/2-year-old cat had myeloproliferative disease characterized by severe anemia. Peripheral blood had a profusion of relatively normal-appearing nucleated erythroid cells in all stages of development and a few primitive cells with nucleoli. The term "erythremic myelosis" best described the appearance of the peripheral blood. Two weeks later, the peripheral blood picture was that of regenerative anemia. During the next 2 months the cat made an apparent clinical recovery without treatment, but relapsed 3 months after the initial examination. One-fourth of the cells in circulation at the time of relapse contained nucleoli and appeared identical to those described in reticuloendotheliosis in cats. This transition suggested the progressive development of a greater degree of immaturity of erythroid precusors with time. The use of the term "reticuloendotheliosis" in conjunction with feline myeloproliferative disease was considered and determined inappropriate.

Animals↗
PubMed1978

Ultrastructure of erythrocytes parasitized by Haemobartonella felis.

Experimental Haemobartonella felis infections were studied in 3 mature, intact cats by examining peripheral blood, lung, and spleen by electron microscopy. Coccoid, rod, or ring forms of the organism were found on or close to the erythrocytic membrane, and adjacent parasitized erythrocytes often were attached. Intracytoplasmic crystalloid inclusions occupying most of erythrocytic cytoplasm were seen in the 3 infected cats. The cat with the highest parasitemia had inclusions in about 10% of the erythrocytes. Less than 0.01% of the erythrocytes of a control cat contained inclusions. Parasitized erythrocytes, with and without inclusions, were seen in capillaries of the lung and spleen of infected cats. Macrophages in the lung and spleen of infected cats contained parasitized erythrocytes, either with or without inclusions. Some macrophages contained erythrocyte-free organisms in phagocytic vacuoles.

Anaplasmataceae↗
PubMed1978

Effects of diet on feline urine.

Urine specific gravity, osmolality, and the incidence of proteinuria were assessed in 18 caged cats. The values for these parameters were increased when dry, as compared to moist, cat food was fed. Failure to recognize these characteristics of feline urine could lead to erroneous interpretations of laboratory data since elevation of these values, particularly protein, has been associated with renal disease.

Animal Feed↗
PubMed1977

Encephalomyocarditis virus infection of captive elephants.

Four African elephants at each of 2 widely separated zoologic gardens in Florida died following a fulminating illness. Tissue suspensions obtained from an elephant from each of the zoologic gardens were inoculated into newborn mice, 3- to 4-week-old mice, and buffalo green monkey and baby hamster kidney cell cultures. Encephalitis and myocarditis developed in the mice. The cell cultures were destroyed within 24 to 72 hours, and intracytoplasmic viral inclusions were observed in infected cells by electron microscopy. The viral agent was neutralized by known antiserum to encephalomyocarditis virus.

Animals↗
PubMed1977

Fatal generalized feline viral rhinotracheitis in a young adult cat.

A 7-month-old cat died following a 17-day illness. Necropsy findings included sharply demarcated lingual ulcers and multifocal necrotic hepatitis. Intranuclear inclusions were found in the lesions, and a herpesvirus was recovered from specimens of liver and tongue. The virus was identified by neutralization with specific antiserum as feline rhinotracheitis virus.

Animals↗
PubMed1977

An epizootic among knots (Calidris canutus) in Florida. I. Disease syndrome, histology and transmission studies.

About 150 knots found sick or dead had distention of serosal blood vessels, and small, raised hemorrhagic foci on the serosal surface of the jejunum and ileum. The principal finding was endaortitis with large intimal multinucleated cysts that contained a protozoan parasite within a cytoplasmic vacuole. There was endarteritis of mesenteric arteries and muscular arteries of the external layers of the intestinal tract. Single or multiple schizont-like stages containing zoites were in the wall of the small intestine and close to affected muscular arteries. The more usual intestinal lesion was an aneurysm of the inflamed muscular artery. It was concluded that endarteritis led to colonic infarction. Schizonts in medullary renal tubular cells were smaller than stages in the intestine. There was necrosis of epithelial cells of themedullary collecting ducts and inflammatory and regenerative changes. Schizonts and zoites were free in collecting ducts and ureters.

Animals↗
PubMed1977

An epizootic of waterfowl associated with a red tide episode in Florida.

During February and March, 1974, an epizootic involving lesser scaup (Aythya affinis) occurred in the Tampa Bay area on the west coast of Florida. Several thousand ducks are estimated to have died. Concurrent with this epizootic was a red tide caused by heavy blooms of the toxic dinoflagellate Gymnodinium breve intoxication were evident in some of the lesser scaup. A controlled experimental feeding of G. breve toxic material to White Pekin ducklings produced illness and death with signs comparable to some of those seen in the scaup.

Animals↗
PubMed1977

Equine antibody to bovine serum induced by several equine vaccines as a source of extraneous precipitin lines in the agar gel immunodiffusion test for equine infectious anemia.

Precipitin lines not associated with equine infectious anemia (EIA) were observed in routine agar gel immunodiffusion (AGID) testing for the infection. The serums which produced these lines were obtained from horses which had been given multiple vaccinations with commercially available cell culture-origin equine virus vaccines as part of a comprehensive herd health program. The lines formed against cell culture-derived, but not spleen-derived EIA viral antigens. Investigation revealed that bovine serum proteins in the vaccines induced precipitating antibodies which reacted with bovine serum proteins in cell culture-derived antigens. A vaccination trial, utilizing 4 commercially available vaccines in various combinations, indicated that as few as 2 vaccinations could induce AGID-detectable antibodies to bovine serum proteins in individual ponies. These antibodies were very transitory, usually lasting no longer than a week. Some horses, however, which had been given 4 vaccinations developed similar antibodies which persisted 3 months beyond the last vaccination. The extraneous precipitin lines produced by these antibodies in the AGID test for EIA were readily distinguished from true EIA-associated reactions and did not result in false-positive interpretations of the test. However, heavy percipitin lines due to strong antibovine serum activity did mask weakly positive EIA reactions.

Animals↗
PubMed1975

Psittacine herpesvirus infection resembling pacheco's parrot disease.

Herpesvirus was detected by electron microscopy in hepatocytes of psittacine birds that died at a Florida aviary. The virus was identified in hepatocytes of chick embryos and budgerigars that were given injections of liver suspensions from naturally infected psittacines. Infected hepatocytes had prominent intranuclear inclusions that contained naked nucleocapsids. Both naked and enveloped virions were seen in the cytoplasm of hepatocytes, and enveloped nucleocapsids occasionally were seen in the perinuclear cisternae and extracellularly. The experimental and spontaneous disease mimicked a condition in parrots described previously by Pacheco. The viral agent was classified as Herpesvirus on the bases of the character of the intranuclear inclusions, the size and conformation of the agent as determined by electron microscopy and filtration, and the sensitivity of the agent to ether.

Animals↗
PubMedDate not supplied

Postoperative examination of the biceps femoris muscle sling used in excision of the femoral head and neck in dogs.

Twenty-four dogs underwent unilateral excision of the femoral head and neck. An adjunctive biceps femoris muscle sling procedure was done in 16 dogs. In eight dogs (controls), the flap was dissected and returned to its original position. Four dogs with muscle slings were euthanatized on days 2, 5, 30, and 60, respectively. Four control dogs were euthanatized on day 2 and four dogs on day 5. Limb function did not differ consistently between dogs with muscle slings and control dogs. There was marked swelling and edema of the affected limb in half the dogs with muscle slings but not in the controls. Postoperative temperature elevations were significantly higher in dogs with muscle slings on days 1 and 2 (p less than 0.05). Infection was documented in four dogs with muscle slings. Flaps from control dogs had only minor gross and histologic abnormalities. On days 2 and 5, flaps from dogs with muscle slings appeared congested and swollen beneath and distal to the ostectomy site, with infarction involving 50 to 90% of the muscle mass. On days 30 and 60, the muscle slings were atrophic and fibrous, and by day 60 a synovial membrane covered the surfaces of all slings within the pseudarthrosis. Muscle fiber loss was attributed to infarction, necrosis, and disuse atrophy.

Animals↗
PubMedDate not supplied

Magnetic resonance imaging of renal abscess in an experimental animal model.

The value of magnetic resonance imaging (MRI) in the diagnosis of renal abscess was investigated in an experimental animal model. MRI is capable of depicting the location and extent of the inflammatory process using T1 weighted scans because of relatively long T1 relaxation values which were significantly longer than T1 relaxation times of adjacent normal renal parenchyma.

Abscess↗