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Biomedical subjects

G G Long

Publications and source records attributed to G G Long.

At least 37 records · Page 2Linked to original sources

Lymphocytic-plasmacytic colitis in the cat.

Lymphocytic-plasmacytic colitis was diagnosed in 6 cats. Owners sought veterinary care because of semiformed -to-liquid feces, tenesmus , fresh blood and/or mucus in the feces, or increased frequency of defecation in their cats. Lymphocytic, plasmacytic infiltration in the colonic lamina propria was found on colon biopsies. Clinical signs resolved in all 6 cats after dietary management, utilizing lamb and rice, horsemeat , or a feline prescription diet. Clinical improvement also occurred in 1 cat following sulfasalazine therapy.

Animals↗

Acute toxicosis in swine associated with excessive dietary intake of vitamin D.

Acute toxicosis developed in a group (n = 35) of fattening hogs and replacement gilts that had excessive vitamin D3 inadvertently added to their feed. All of the pigs were lethargic, and emesis was evident in about half of the pigs 1 to 2 days after they consumed the feed. On the 2nd day, 3 of the pigs died. The remaining pigs were given a different ration. Five additional pigs died during the next 2 weeks. Clinical toxicosis also was observed in 1 of 2 feeder pigs fed the suspect feed in the laboratory and in 2 of 2 pigs fed the suspect feed by the company that had mixed the feed. Gross necropsy findings consistently observed were hemorrhagic gastritis and diffuse interstitial pneumonia. Myocardial degeneration and nephrosis were seen in, respectively, 1 of 6 and 4 of 6 pigs necropsied. Histologically, necrosis and mineralization of variable severity were observed in the fundic gastric mucosa, lungs, kidneys, bone, heart, and small blood vessels of the lungs and heart. Less necrosis and more mineralization were observed in pigs that survived longer than 6 days. The 2 pigs fed the suspect feed in the laboratory had increased concentrations of serum calcium from the 3rd to the 9th days or the 1st to the 3rd days, after feeding the suspect feed. Serum phosphorus concentrations were increased from the 1st until the 2nd or 3rd day, and serum magnesium concentrations were increased from the 1st or 2nd to the 3rd day after feeding the suspect feed.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Effect of purified zearalenone on early gestation in gilts.

Purified zearalenone (Z) was added to the diet of gilts from d 2 to 15 postmating. Gilts received either 0, 5, 15, 30, 60 or 90 ppm Z (three to five gilts per dose) in 1.8 kg of feed daily. Serum concentrations of progesterone and estradiol-17 beta were determined weekly. On d 13 to 15 and 40 to 43 postmating, blood samples were drawn from a cannula at 20 min intervals for 4 h and analyzed for luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL). Gilts were killed 40 to 43 d postmating and embryonic development was assessed. Treatment with 5, 15 or 30 ppm Z had no effect on embryonic development when compared with 0 ppm. No fetuses were present in gilts fed 60 to 90 ppm Z, but two gilts given 60 ppm Z had remnants of fetal membranes in the uterus. The histologic appearance of reproductive tract tissues from the gilts given 60 ppm Z was similar to that from pregnant gilts. Tissues from gilts given 90 ppm Z appeared to be stimulated by both estrogen and progesterone. Serum concentrations of progesterone were decreased at 2, 3 and 6 wk postbreeding in gilts fed 60 and 90 ppm Z. Serum concentrations of estradiol-estradiol-17 beta were decreased at 4 wk postbreeding in gilts fed 60 and 90 ppm Z.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

Effect of Fusarium roseum (Gibberella zea) on pregnancy and the estrous cycle in gilts fed molded corn on days 7-17 post-estrus.

A laboratory produced corn culture of Fusarium roseum (Gibberella zea) was fed as 10% of the total diet to bred and non-bred gilts on days 7-17 postestrus. The corn culture contained both zearalenone and deoxynivalenol by analysis, and caused considerable feed refusal. Although 6 of 10 bred gilts fed the corn culture appeared to be pregnant by ultrasound testing between days 40-50 post-breeding, none of them farrowed. Progesterone analyses indicated that none of the 10 gilts cycled normally during the 20 week observation period. Three maintained high serum progesterone (greater than 10 ng/ml) during the entire period. Progesterone analyses were similar in 5 non-bred gilts fed the corn culture in that none of them cycled normally in 20 weeks. The retention or loss of corpora lutea could not be attributed to levels of luteinizing hormone, as no relationship was found between concentrations of progesterone and luteinizing hormone. This experiment indicates that limited dietary exposure of female swine to Fusarium roseum infected corn can result in embryonic loss and disruption of normal reproductive cycling for an extended length of time.

Animal Feed↗

Effect of Fusarium roseum corn culture containing zearalenone on early pregnancy in swine.

A corn culture of Fusarium roseum was added to a standard corn-soybean swine gestation ration. Low, middle, and high dosage mixed feeds contained 7, 38, and 64 mg of zearalenone/kg of feed (7, 38, and 64 ppm) and 0.5, 2.5, and 4.5 mg of deoxynivalenol/kg, respectively. Control feed was the standard ration without added F roseum corn culture. Mature gilts were bred by natural service and fed control or F roseum molded feed from 3 to 34 days after breeding. The main effect of the molded feed was an inhibition of fetal development, with decreased numbers of fetuses present in treated animals at slaughter (38 to 43 days after breeding). Normal litters were present in 7 of 8 control animals, in 2 of 4 gilts given the low-dosage feed, in 1 of 4 gilts given the medium dosage, and in 0 of 4 given the high-dosage feed. Corpora lutea were maintained in all treated animals, as evidenced by serum progesterone concentrations. Serum estradiol concentrations were decreased in gilts in the middle- and high-dosage groups. The genital system of the gilts fed low- and middle-dosage feeds had a gross and microscopic appearance similar to that of the pregnant controls and reflected prolonged progesterone stimulation. Morphologic changes in the genital system of the high-dosage group were intermediate between changes induced by progesterone and those induced by estrogen. Clinical signs of hyperestrogenism and partial feed refusal were noticed in only some of the high-dosage group animals.

Animals↗

Field studies: pseudomonas pneumonia of mink.

Epizootics of pneumonia in mink caused by Pseudomonas aeruginosa were investigated to characterize the serotype of organisms and to identify possible predisposing factors. Most epizootics were associated with P aeruginosa Fisher serotype 1, and a few were associated with 3 other serotypes. There were no predisposing factors identified that could be used to differentiate farms affected and those not affected with pseudomonas pneumonia. Cultural studies indicated that P aeruginosa was present in mink from affected and nonaffected herds. Organisms isolated included serotypes associated with naturally occurring disease. Serostudy results were similar among herds. A prospective field vaccination trial did not yield definitive results, since only slight losses occurred in both vaccinated and nonvaccinated mink. Significant levels of antibody were detected in mink 15 to 17 weeks after they were given a single dose of P aeruginosa lipopolysaccharide vaccine.

Animals↗

Metastatic canine medullary thyroid carcinoma: a case report.

A medullary carcinoma of the thyroid in a dog first became evident because of a distant metastasis. The histologic characteristics of the tumor differ from those previously reported in dogs in that this tumor was highly malignant; anaplasia and mitotic figures were common. The diagnosis was substantiated by radioimmunoassay for calcitonin. Serotonin and 5-hydroxytryptophan also were elevated in the neoplastic tissue. The relation of the biochemical alterations to the clinical course was not clear.

5-Hydroxytryptophan↗

Naturally occurring picornavirus infection of domestic mink.

The isolation and preliminary characterization of a virus from domestic mink- are reported. The virus was tentatively classified as a member of the family Picornaviridae on the basis of its physicochemical properties. The mink virus was not neutralized by antiserum to some known members of the calicivirus genus, which included the nine serotypes of vesicular exanthema of swine virus, ten serotypes of San Miguel sea lion virus and feline calicivirus. Seroepidemiological studies indicated that the incidence of mink virus infection was widespread in domestic mink populations. Although the virus was isolated from mink on ranches with a history of hemorrhagic pneumonia (pseudomonas pneumonia), no specific disease process could be attributed to the virus infection.

Animals↗

Pseudomonas pneumonia of mink: pathogenesis, vaccination, and serologic studies.

Fulminating pneumonia was produced in mink by the intratracheal administration of Pseudomonas aeruginosa. The sequence of pulmonary lesions was focal inflammation, focal necrosis, and widespread inflammation and necrosis. Secondary lesions of peracute hemorrhage and necrosis were the result of bacterial spread via the airways. Invasion of vessel walls by P aeruginosa was a terminal event and was secondary to bacillary invasion and necrosis of adjacent tissues. Regional (lymphatic) and systemic spread of bacteria followed the development of pulmonary lesions, but there was little morphologic evidence of tissue damage in other organs. Immunofluorescence studies showed that P aeruginosa antigen was dispersed within pulmonary cells and was free in the lung parenchyma. Mink surviving beyond postinfection hour 60 had a macrophage infiltration into limited pulmonary lesions. A vaccine trial was conducted with P aeruginosa lipopolysaccharides (LPS) used as antigen, and an enzyme-linked immunosorbent assay was used to detect antibody. Antibody was detected in mink after vaccination with LPS or natural exposure. Mink with antibody to LPS, from vaccination or naturally acquired, were resistant to experimental infection.

Animals↗

Pathogenesis of respiratory Klebsiella pneumoniae infection in rats: bacteriological and histological findings and metabolic alterations.

Gram-negative bacterial pneumonias have been increasingly important as nosocomial infections. The following model was developed to study the pathogenesis and evaluate therapy of such infections. Intranasal instillation of rats with a suspension of 5 x 10(6) Klebsiella pneumoniae caused bronchopneumonia with 24 h. Bacteria were isolated from the lungs in large numbers (greater than 10(5) colony-forming units [CFU] for at least 13 days after inoculation. Thereafter, the viable concentration decreased to about 10(3) CFU at 21 days but increased to 10(4) CFU at 25 days. Mortality rarely exceeded 25%. Plasma zinc concentration decreased, and plasma seromucoid, lysozyme, and alpha2-macrofetoprotein increased during respiratory K. pneumoniae infection in rats. There seemed to be a linear relationship between seromucoid concentration and the concentration of K. pneumoniae in the lung expressed in log10 units. Plasma zinc, alpha2-macrofetoprtoein, or lysozyme levels, however, did not change until the concentration of bacteria retrieved fron lungs exceeded 4 to 5 logs, Analysis of blood samples obtained serially from the orbital sinuses revealed that rats that succumbed to infection had significantly higher levels of seromucoid, alpha2-macrofetoprotein, and lysozyme and lower levels of plasma zinc than infected rats that survived. Progressive increases in seromucoid and particularly in lysozyme and alpha2-macrofetoprotein appeared to be predicative of death. It is postulated that the threshold effect observed for alpha2-macrofetoprotein and lysozyme reflect significant damage to lung tissue, and thus these two variables are good indexes of the severity of this infection. We propose that this model may be of value in elucidating the pathogenesis of respiratory K. pneumoniae as well as in assessing various models of therapy.

Animals↗