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Biomedical subjects

L D Olson

Publications and source records attributed to L D Olson.

At least 73 records · Page 4Linked to original sources
PubMed1976

A direct fluorescent antibody test for large spirochetes in swine dysentery using hyperimmunized swine serum.

A direct fluorescent antibody test was developed for the identification of large spirochetes which are considered to be the cause of swine dysentery. Sera from swine which had recovered from swine dysentery and had been hyperimmunized by the intravenous and intraperitoneal injection of filtered spirochetes were used for conjugation with fluorescein isothiocyanate. A bright greenish fluorescence of large spirochetes was observed with the conjugated serum from hyperimmunized pig No. 1 when diluted 1:8 and hyperimmunized pig No. 2 when diluted 1:2. Pig No. 1 had developed a serum titer of 1:64 using the indirect fluorescent antibody test for large spirochetes. The conjugated serum from the three swine which had recovered from swine dysentery fluoresced spirochetes only when undiluted. The conjugated serum from the two swine treated while having a hemorrhagic diarrhea did not fluoresce spirochetes. No immunofluorescence of Vibrio spp. was observed.

Animals↗
PubMed1976

Immunofluorescence of spirochetes with serum from swine recovered from swine dysentery using an indirect fluorescent antibody test.

Using an indirect fluorescent antibody test, immunofluorescence of large spirochetes was observed with serum from swine that had recovered from swine dysentery. The spirochetes were obtained from scrapings of the colonic mucosa on the first day of diarrhea which was the time when the spirochete population was observed to be the highest. Of 29 exposed nonmedicated swine which developed and recovered from a diarrhea characteristic of swine dysentery 27 had antispirochete serum titers which ranged from 1:2 to 1:16. None of the 50 nonexposes swine developed a titer. Of 19 swine with a serum titer and reexposed with infective swine dysentery inoculum, 18 did not develop a diarrhea and were presumed to be immune. Considering these findings it is possible that this test could be used to detect antispirochete antibody in unknown swine serum.

Animals↗
PubMed1976

Ronidazole in high concentrations in drinking water for treatment and prevention of diarrhea in swine dysentery.

Ronidazole administered in the drinking water at concentrations of 0.012, 0.006, and 0.003% was effective for the treatment of swine dysentery. All groups of medicated swine had more survivors, fewer days of hemorrhagic and nonhemorrhagic diarrhea, greater feed consumption, greater weight gain, and more favorable feed efficiency than did nonmedicated swine. The only adverse clinical sign and lesion observed in the medicated swine comprised the drug-delayed-augmented swine dysentery which affected 3 swine in a group given 0.003% ronidazole. Several of the swine given the 0.012% concentration developed nonhemorrhagic diarrhea while on medication, probably because of the high concentration of the drug. Diarrhea did not recur in swine after the withdrawal of medication in both of 2 groups given the 0.012% concentration, in 3 of 4 groups given the 0.006% concentration, or in 1 of 4 groups given the 0.003% concentration. One or more swine were susceptible to reexposure to swine dysentery in both groups given the 0.012% concentration, in 1 group given the 0.006% concentration and in 1 group given the 0.003% concentration. Large spirochetes were observed in fecal smears from all exposed swine which developed either hemorrhagic or nonhemorrhagic diarrhea.

Administration, Oral↗
PubMed1976

Ronidazole in low concentrations in drinking water for treatment and development of immunity to swine dysentery.

The addition of ronidazole to the drinking water at the concentration of 0.003% was effective for the treatment of experimentally induced swine dysentery in swine. Ronidazole at concentrations of 0.0015% and 0.00075% aided in the treatment of swine dysentery and the development of immunity to the disease. In experiment I, in which swine were given concentrations of 0.003, 0.0015, and 0.00075%, there were more survivors, fewer days of hemorrhagic diarrhea, greater feed and water consumption and body weight gain, and more favorable feed efficiency in the medicated swine than in the nonmedicated swine. With the 0.003% concentration, there were no deaths, and the diarrhea receded during or after treatment with the 0.0015% and 0.00075% concentrations, the incidence of nonhemorrhagic diarrhea was greater in medicated than in nonmedicated swine, and the diarrhea did not subside during treatment. In experimetn II, there were more survivors in the groups of swine medicated with the 0.0015% concentration than in the nonmedicated groups of swine. All surviving nonmedicated swine in experiment I were immune to reexposure 3 months after initial exposure. More swine given to the 0.0015% and 0.00075% concentrations in the same experiment were immune to reexposure 3 months after initial exposure than were the swine given the 0.003% concentration. In experiment II, neither the swine previously medicated with the 0.0015% concentration nor the nonmedicated swine were immune to reexposure 5 weeks after initial expsoure. Large spirochetes were observed in fecal smears from all exposed swine which developed either hemorrhagic or nonhemorrhagic diarrhea.

Administration, Oral↗
PubMed1975

The use of ketamine hydrochloride as an anesthetic for raccoons.

Ketamine hydrochloride was observed to be an effective anesthetic for recently captured raccoons (Procyon lotor) when they were injected intramuscularly with 20-29 mg/kg body weight. Excellent anesthesia occurred from 5 to 15 min after injection. No respiratory difficulties were encountered. The only undesirable clinical sign was excessive salivation.

Anesthesia, General↗
PubMed1974

Clinical and pathological observations on the experimental passage of swine dysentery.

The length of incubation for 36 eight and 12 week old swine in eight experimental passages averaged 11 days and ranged from five to 24 days. The duration of diarrhea for 24 of these swine averaged 6.4 days and ranged from two to 19 days. The consistent macroscopic lesion was a colitis and, subsequently, a typhlitis. In the swine euthanized on the first day of diarrhea, the colitis was most intense in the coils near the apex of the colon and, frequently, these swine had a hyperemia of the fundus of the stomach. The amount of visible blood in the colon varied. Organisms identified microscopically and ultrastructurally as spirochetes were observed commonly in the feces and the mucosal glands of the colon of swine with a diarrhea, but not in the adjacent mesenteric lymph nodes. These spirochetes which were the most numerous on the first day of diarrhea, could not be isolated and propagated in vitro. Swine which recovered naturally or were medicated at the height of a diarrhea, developed a resistance to swine dysentery. Colon from infected swine remained infectious when stored at -77 degrees C for nine months but not when stored at -16 degrees C. Feces from infected swine were not infectious after lyophilization and storage at -12 degrees C.

Animals↗
PubMed1973

Duration of viability and the growth and expiration rates of group E streptococci in soil.

In irradiated and nonirradiated feedlot and pasture soils inoculated with group E streptococci, the organism was not recovered 17 days postinoculation from either the irradiated or nonirradiated feedlot soils incubated at 37 C, but survived in the irradiated pasture soils for 24 and 31 days postinoculation. The streptococci survived in irradiated and nonirradiated soils incubated at 4 C for 116 days and in one irradiated feedlot soil for 165 days. The population of streptococci did not increase in either irradiated or nonirradiated soil, and the expiration rate was greater in the soils incubated at 37 and 25 C than at 4 C. With the relatively prolonged duration of viability of group E streptococci in soil at 4 C, it is suggested that soil contaminated with exudate from draining abscesses of infected swine could act as a source of infection during the colder season.

Animals↗
PubMed1973

In vitro studies of group E streptococci in swine leukocytes. I. Phagocytic and bactericidal properties of polymorphonuclear leukocytes from swine.

Serum from both immune and nonimmune ten-week-old swine contained factors which promoted phagocytosis of group E Streptococci (GES). The factors in nonimmune serum, which were heat labile at 70 degrees C for ten minutes, were less efficient than the factors present in immune serum.Bactericidal activity of the polymorphonuclear (PMN) leukocytes against GES was observed with serum from both immune and nonimmune ten-week-old swine, as well as with serum from normal sows and piglets. However, the bactericidal activity of PMN leukocytes in serum from either normal sows or immune ten-week-old swine was greater than the bactericidal activity of PMN leukocytes in either piglet serum or serum from nonimmune ten-week-old swine. When the serum was either heated to 70 degrees C for ten minutes or treated with 2-mercaptoethanol, bactericidal activity of PMN leukocytes against GES was only observed in the presence of immune serum.

Animals↗
PubMed1973

In vitro studies of group E streptococci in swine leukocytes. II. Phagocytic and bactericidal properties of macrophages from immune and nonimmune swine.

Macrophages collected from susceptible swine and grown in nonimmune serum phagocytized and digested group E Streptococci (GES). However, macrophages collected from immune swine and grown in nonimmune serum were capable of much higher rates of phagocytosis and intracellular digestion of the organism. The addition of immune serum to cultures of immune macrophages increased the rate of phagocytosis but not the rate of intracellular digestion of GES by the macrophages. These findings are discussed in relation to mechanisms of cellular immunity.

Animals↗
PubMed1973

In vitro studies of group E streptococci in swine leukocytes. 3. The migration inhibition test as an indication of delayed hypersensitivity in streptococcic lymphadenitis.

A procedure for conducting tests for leukocyte migration inhibition was developed for swine leukocytes. Leukocytes from normal swine were found to be inhibited by a factor of less than 20% in the presence of the whole cell antigen of group E Streptococci (GES). However, the migration of leukocytes from swine which had been exposed to GES was inhibited by more than 60% in the presence of the antigen. This was considered as significant and an indication for the presence of delayed hypersensitivity to GES in previously exposed swine.

Animals↗
PubMed1973

Transmissible gastroenteritis in feeder swine: clinical, immunofluorescence and histopathological obervations.

Eight feeder swine (four to six months of age) were inoculated orally with 200,000 to 500,000 pig infectious doses (PID) of the Purdue strain of transmissible gastroenteritis (TGE) virus. Biopsies obtained from their small intestines were examined histopathologically and by fluorescent antibody tissue section technique at intervals that included 24, 48, 72 and 96 hours postexposure, and similar examinations were carried out at necropsy 168 hours postexposure. Evidence of virus infection was demonstrated in all segments of the small intestine except the upper duodenum and the viral antigen was found only in the cytoplasm of the absorptive cells covering the villi. Although six of the eight pigs failed to show clinical signs of TGE, typical microscopic lesions of villous atrophy with replacement of columnar absorptive cells by cuboidal cells were observed in seven pigs, and TGE virus antigen was demonstrated in the intestinal cells of four of eight pigs during the first week postexposure. The infection was usually mild to moderate and focal in the pigs without clinical signs of the disease and more severe and extensive in the pigs with clinical signs of the disease variable in severity. It was concluded that TGE virus probably replicated in all feeder swine exposed, and that the presence or absence of clinical signs of TGE in these pigs was related to the severity and extent of the villous atrophy and columnar cell replacement induced in their small intestines.

Administration, Oral↗
PubMed1973

Viability and ultrastructural changes in group E Streptococci after in vitro phagocytosis by swine macrophages.

The loss of viability and ultrastructural changes were studied in group E Streptococci (GES) after in vitro phagocytosis in immune swine macrophages. There was a 50% reduction in the viability of intracellular GES during the first 60 minutes of incubation and a total loss of viability by 300 minutes as compared to the control tubes where the GES increased. Loss of viability in phagocytized group E Streptococci was associated with the appearance of degenerative changes in the bacterial cytoplasm. This was followed by disruption of the bacterial cell membrane and its separation from the bacterial cell wall. No definite evidence of cell wall degeneration could be found. Unphagocytized organisms incubated for similar periods and fixed in the same manner did not lose viability nor have any degenerative changes.

Animals↗
PubMed1973

A direct fluorescent antibody test for identification of group E streptococci.

A rapid and specific direct fluorescent antibody test was developed for the identification of group E Streptococci (GES). Tests for specificity included an inhibition test and application of the conjugate to smears of Staphylococcus aureus, Pasteurella multocida, and streptococci of Lancefield's groups, A, B, C, D, E (types I, IV and untypeable), F and G. With the inhibition test, a specific blocking reaction occurred and the conjugate cross-reacted only with group C Streptococci (GCS). Adsorption with GCS eliminated the cross-reaction and rendered the conjugate specific for GES.

Adsorption↗