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Biomedical subjects

A B Larsen

Publications and source records attributed to A B Larsen.

At least 19 recordsLinked to original sources
PubMed1988

Comparative plasma concentration profiles after i.v., i.m. and rectal administration of pethidine in children.

Plasma concentration-time curves of pethidine and norpethidine were studied in 25 children allocated after operation to three groups to receive pethidine 1 mg kg-1 i.v., i.m. or rectally. Peak concentrations occurred after 5 +/- 1, 10 +/- 2, and 60 +/- 10 min, respectively, while the maximum concentrations amounted to 2800 +/- 462, 1609 +/- 367 and 531 +/- 179 nmol litre-1, respectively. The area under the curve (0-240 min) was similarly reduced in the group with rectal administration (P less than 0.05). Compared with the i.v. data, approximately 40% systemic availability occurred after rectal application, although considerable individual variation was noted. In one child very high plasma concentrations were observed after rectal administration, possibly as a result of redistribution/recirculation phenomena. The average results are similar to those obtained when other opioids are given rectally.

Administration, Rectal↗
PubMed1981

Mycobacterium paratuberculosis in the semen and genital organs of a semen-donor bull.

Mycobacterium paratuberculosis, the cause of Johne's disease, was isolated from the feces of a donor bull in an artificial insemination stud. During isolation and observation for 21 months, the organism was recovered from all of 26 fecal samples and from 8 of 31 semen samples. At necropsy, it was isolated from the intestine and adjacent lymph nodes, lung, spleen, seminal vesicles, and prostate gland but not from the testicles. We concluded that routine fecal cultures at bull studs will reveal infected bulls before they become genitally infected and shed M paratuberculosis in semen.

Animals↗
PubMed1979

Susceptibility of the lemming (Dicrostonyx rubricatus) to Mycobacterium paratuberculosis.

The susceptibility of the lemming (Dicrostonyx rubricatus) to Mycobacterium paratuberculosis was studied. Twelve lemmings were exposed to cultural material of M paratuberculosis and were necropsied at 40- to 260-day intervals after exposure. Selected tissues were examined bacteriologically and histologically. Mycobacterium paratuberculosis was recovered from all exposed lemmings except the one necropsied 40 days after exposure. Pathologic changes typical of paratuberculosis were seen in a few lemmings. Clinical signs of disease were not seen. Rate of growth and general appearance of the exposed lemmings and the normal controls did not differ. The extent of infection in this species of lemming was similar to that seen in exposed hamsters.

Animals↗
PubMed1978

Effect of dexamethasone on Mycobacterium paratuberculosis infection in hamsters.

Sixty hamsters were randomly divided into 4 equal groups: group 1--given only dexamethasone, group 2--given dexamethasone and exposed to Mycobacterium paratuberculosis, group 3--exposed to M paratuberculosis but not treated, and group 4--used as normal controls. Group 2 hamsters (treated with dexamethasone and exposed to the bacterium) had significantly higher bacterial counts in spleen and aggregated lymphatic nodules (Peyser's patches) than did those in group 3. None of the hamsters exposed to M paratuberculosis (groups 2 and 3) developed clinical signs of disease. All hamsters treated with the drug (groups 1 and 2) grew more slowly than did the hamsters not treated.

Animals↗
PubMed1978

Mammary gland exposure of cows to Mycobacterium paratuberculosis.

Mycobacterium paratuberculosis injected into the mammary gland was transported to the supramammary lymph nodes in 5 of 6 cows and to the intestine of 1 cow. The bacillus caused hypersensitivity to johnin and stimulated the production of complement-fixing antibodies. Apparently, the bacillus is not a cause mastitis.

Animals↗
PubMed1977

Skin testing, fecal culture, and lymphocyte immunostimulation in cattle inoculated with Mycobacterium paratuberculosis.

Fourteen calves at 21 days of age were experimentally inoculated with 100 mg (wet weight) of Mycobacterium paratuberculosis. Three calves were inoculated orally, 4 intravenously, and 7 subcutaneously. Lymphocyte immunostimulation, fecal culture, and intradermal tuberculin skin testing were done between 112 to 150 days following exposure. Lymphocyte immunostimulation test results, conducted at 112 days after inoculation, showed all animals positive to Mycobacterium avium purified protein derivative. Fecal culture results, taken at 120 days after inoculation, showed that 2 of 3 animals inoculated intravenously were positive, whereas only 2 of 7 inoculated subcutaneously were positive (8 of 14 total were positive). Intradermal skin testing results at 150 days with M avium purified protein derivative showed 13 of the 14 calves were positive. Calves were examined at necropsy 153 days after inoculation, and M paratuberculosis was isolated from tissues of each of the 14 calves.

Animals↗
PubMed1977

Subcutaneous exposure of calves to Myobacterium paratuberculosis compared with intravenous and oral exposures.

Three groups of calves, 21 days of age, were exposed to Mycobacterium paratuberculosis by oral, intravenous, and subcutaneous routes. Fecal cultural examination and intradermal tests were made, and at 150 days after exposure, the calves were euthanatized and tissues were collected for histopathologic and bacteriologic cultural examination. Calves in the 3 groups were infected. Those exposed intravenously had significantly higher colony counts than did either of the other groups. There was no significant difference between colony counts of cultures from tissues of calves exposed orally and those of calves exposed subcutaneously.

Administration, Oral↗
PubMed1975

Age of cattle as related to resistance to infection with Mycobacterium paratuberculosis.

Two 1-month-old calves, four 9-month old calves, and 4 adult (5 to 11 years old) cattle were exposed to Mycobacterium paratuberculosis. At 150 days after exposure, all cattle were killed and necropsied, and at that time, tissues of the 1-month-old calves had more bacilli and lesions than did tissues of the 9-month-old calves or the adult cattle. All cattle responded to immunologic tests during the experiment.

Administration, Oral↗