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Biomedical subjects

B K Gustafsson

Publications and source records attributed to B K Gustafsson.

12 recordsLinked to original sources
PubMed1988

Distribution of chloramphenicol in the genital tract of postpartum cows.

Chloramphenicol was administered by constant IV infusion to 7 healthy postpartum cows at rates predicted to approach a steady-state plasma concentration of 5 micrograms/ml. After 8 hours of constant IV infusion, uterine tissues were removed surgically and were assayed for chloramphenicol concentrations. Mean plasma-to-tissue ratios of chloramphenicol concentrations were 3.05, 3.63 (6 cows only), and 3.22 for caruncles, endometrium, and uterine wall, respectively. Plasma-to-tissue ratios of the 3 tissues were not significantly different (P greater than 0.10). Intrauterine (IU) injections of chloramphenicol (20 mg/kg of body weight) were administered to 3 healthy post-partum cows. The mean value of the fraction of the drug absorbed from the uteri of these cows was 0.40. Mean concentrations of chloramphenicol were 43.8 micrograms/g in caruncles, 34.6 micrograms/g in endometrium, 2.8 micrograms/g in uterine wall, and 2.9 micrograms/ml in plasma 8 hours after IU injections. Chloramphenicol has now been banned for use in food-producing animals in the United States because of its potential for causing toxicosis in human beings. It is illegal to use chloramphenicol in food-producing animals in the United States and in some other countries as well. This includes use by the IU route of administration because chloramphenicol and most drugs are absorbed from the uterus into the bloodstream and are distributed to milk and tissues.

Animals↗
PubMed1987

Florfenicol in non-lactating dairy cows: pharmacokinetics, binding to plasma proteins, and effects on phagocytosis by blood neutrophils.

Serial blood samples were collected and plasma concentrations of florfenicol (FLO) were measured following the administration of an intravenous bolus of 50 mg/kg FLO to five healthy non-lactating dairy cows. A triexponential equation provided the best fit of the data for four of the five cows. The mean value for beta corresponded to a half-life of 3.2 h. The mean apparent volume of distribution was 0.67 l/kg, and the mean body clearance was 0.15 l/kg/h. The extent of binding of FLO to bovine plasma proteins was determined in vitro at concentrations of 5 micrograms/ml and 50 micrograms/ml by equilibrium dialysis and ultrafiltration. The drug was 18% and 19% bound by equilibrium dialysis, and 23% and 19% bound by ultrafiltration, at 5 micrograms/ml and 50 micrograms/ml, respectively. Phagocytosis of 32phosphorus-labelled Staphylococcus aureus by bovine blood neutrophils was compared in vitro between neutrophils incubated in phosphate-buffered saline alone or in combination with 5, 125, or 1000 micrograms/ml chloramphenicol or FLO. There was no significant effect of chloramphenicol at any concentration. Florfenicol significantly inhibited phagocytosis at all concentrations, but the percentage inhibition was small. The clinical significance, if any, of this effect of FLO remains to be demonstrated.

Animals↗
PubMed1986

Endotoxin-induced bovine mastitis: arachidonic acid metabolites in milk and plasma and effect of flunixin meglumine.

Arachidonic acid metabolites (AAM) were measured in milk and plasma during the course of acute endotoxin-induced mastitis in 12 lactating cows. Mastitis was induced by intramammary challenge exposure with 10 micrograms of Escherichia coli (026:B6) endotoxin. Endotoxin was injected into the teat cistern via the teat canal of a single randomly selected rear quarter of each cow. Concentrations of prostaglandin (PG) F2 alpha and thromboxane (Tx) B2 in fat-free unextracted milk and of 15-keto-13,14-dihydro-PGF2 alpha in plasma were measured by radioimmunoassay. Total production of AAM in milk was determined by measuring quarter milk production. The AAM were compared in 6 cows administered flunixin meglumine (1.1 mg/kg of body weight) and in 6 cows administered saline solution. Concentrations of TxB2 in milk were significantly (P less than 0.001) increased during the early course of acute mastitis in endotoxin-treated quarters of cows not administered flunixin meglumine. Peak concentrations of TxB2 in milk occurred at 8 hours after endotoxin inoculation. Flunixin meglumine treatment produced significant (P less than 0.05) reductions in milk TxB2 and plasma 15-keto-13,14-dihydro-PGF2 alpha concentrations. Concentrations of PGF2 alpha in milk and total PGF2 alpha and TxB2 production per quarter per milking were not significantly influenced by endotoxin challenge or by flunixin meglumine treatment.

Animals↗
PubMed1986

Efficacy of flunixin meglumine for the treatment of endotoxin-induced bovine mastitis.

The clinical effect of flunixin meglumine administration was determined in cows with acute mastitis induced by intramammary administration of endotoxin. In 12 lactating cows, 10 micrograms of Escherichia coli 026:B6 endotoxin were administered via a teat cannula into the teat cistern of single randomly selected rear quarters. Cows were challenge exposed as pairs. One cow in each pair was administered parenteral flunixin meglumine (6 cows) and 1 cow per pair was administered saline solution (6 cows). Multiple doses (7) of 1.1 mg of flunixin meglumine/kg of body weight or saline solution were administered at 8-hour intervals beginning 2 hours after endotoxin. Cow and quarter clinical signs as well as milk somatic cell concentrations, bovine serum albumin, electrical conductivity, and milk production were determined before and for 14 days after endotoxin inoculation. Intramammary endotoxin produced signs characteristic of acute coliform mastitis. Quarter and systemic abnormalities occurred and milk production was reduced by approximately 50% at 12 hours after endotoxin. Flunixin meglumine therapy significantly (P less than or equal to 0.05) reduced rectal temperatures and quarter signs of inflammation and improved clinically graded depression when compared with these signs in saline solution-treated controls. Milk production and laboratory indicators of inflammation in milk were not significantly (P greater than 0.05) different for flunixin meglumine vs saline solution controls. The clinical response observed was consistent with the antipyretic, analgesic, and anti-inflammatory properties of flunixin meglumine.

Animals↗
PubMed1986

Endotoxin-induced bovine mastitis: immunoglobulins, phagocytosis, and effect of flunixin meglumine.

Milk whey immunoglobulins (Ig) and phagocytosis of staphylococci by milk polymorphonuclear neutrophilic leukocytes (PMN) were measured in 12 cows (allotted to 6 pairs) during acute bovine mastitis induced by intramammary inoculation of endotoxin. Six of these cows (or 1 in each pair) were treated with flunixin meglumine and were compared with the others (given only saline solution). The endotoxin inoculation comprised 10 micrograms of Escherichia coli O26:B6 lipopolysaccharide injected into one of the rear quarters (mammae). Flunixin meglumine was administered parenterally at a dosage of 1.1 mg/kg every 8 hours (total of 7 doses) beginning at 2 hours after endotoxin was injected. Milk samples were obtained, and whey samples were prepared from each quarter of each cow 3 times before inoculation and at 2, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168, and 336 hours after endotoxin was inoculated. Significant increases (P less than 0.05) in milk whey IgG1, IgG2, IgM, and IgA concentrations were observed in whey samples from endotoxin-inoculated quarters. Greatest relative increase was seen for IgG2. Increased whey Ig concentrations were not observed in quarters which were not inoculated with endotoxin. Concentrations of whey IgG1 and IgM in endotoxin-inoculated quarters were significantly (P less than 0.05) decreased in flunixin meglumine-treated cows, compared with those in saline solution-treated cows. Significant increases in phagocytosis of staphylococci by milk PMN were observed in whey samples from endotoxin-inoculated quarters. Significant differences in PMN phagocytosis were not found in whey samples from cows given flunixin meglumine when compared with whey samples from cows given saline solution.

Analysis of Variance↗
PubMed1986

Plasma cortisol and norepinephrine concentrations in castrated male pigs maintained in pairs in outdoor pens and in a confinement finishing house: assessment of stress.

A catheter-backpack system was developed for repeated blood collection in pigs. Castrated male pigs (n = 12) were maintained in pairs in outdoor pens and later in a slotted-floor confinement finishing house. Blood collection required no restraint and appeared to be stress free. Serum cortisol concentration was unchanged by mode of maintenance. However, diurnal variation of cortisol was more pronounced when pigs were housed. A significant decrease (P less than 0.05) in serum norepinephrine concentration occurred during the housing period.

Animals↗
PubMed1986

Recording uterine motility in the nonanesthetized bitch.

Spontaneous and drug-induced uterine motility (UM) was recorded in 5 nonanesthetized bitches for 2 to 4 days. Catheter-tip pressure transducers were surgically implanted in 1 uterine horn, tunneled subcutaneously to exit from the skin over the dorsal lumbar area, and protected by a bandage. On the day after implantation, spontaneous UM was recorded in the awake bitch. Effects of IV prostaglandin (PG) F2 alpha (5 micrograms/kg of body weight) and oxytocin (0.05 USP U/kg) and IM PGF2 alpha (25 micrograms/kg) were measured. Estradiol (1 to 25 micrograms/kg) was administered and the study was repeated 24 hours later. In awake bitches, spontaneous UM was 190% greater than UM in anesthetized bitches. Uterine motility was increased by more than 100% after IV PGF2 alpha or oxytocin and by 52% after IM PGF2 alpha. Estradiol abolished spontaneous UM, but did not affect drug-induced responses. Seemingly, spontaneous and drug-induced UM can be documented in the nonanesthetized bitch.

Animals↗
PubMed1985

Arachidonic acid metabolites in milk of cows during acute coliform mastitis.

Concentrations of prostaglandin F2 alpha (PGF2 alpha) and thromboxane B2 (TXB2) were evaluated in the milk of cows with naturally occurring (n = 3) and experimentally induced (n = 5) acute coliform mastitis. These arachidonic acid metabolites were measured by radioimmunoassay in unextracted milk. Experimental infections were induced by inoculating 600 to 1,200 colony-forming units of Escherichia coli into 1 mammary quarter per experimental cow. In the experimental cows, milk was collected before inoculation and at 12, 24, 36, 48, 60, and 72 hours after inoculation. Somatic cell concentrations, bovine serum albumin, and concentrations of PGF2 alpha and TXB2 were determined in milk collected at each sampling. Mild-to-moderate increases in milk PGF2 alpha and TXB2 concentrations were observed in cows with naturally occurring mastitis. the increases corresponded to the clinical severity and course of mastitis. In the experimental cows, increases in milk PGF2 alpha and TXB2 concentrations were observed, but the increases were not significant, using a statistical model that included factors of treatment, cows, hours after inoculation, cows-by-treatment and hours-by-treatment interactions, and random error (residual). Results of the present study indicated a large biological variability in milk arachidonic acid metabolite concentrations in cows with acute coliform mastitis, and that arachidonic acid metabolites may be important in the pathophysiologic process of acute coliform mastitis.

Acute Disease↗
PubMed1979

The use of fibre-optic techniques in clinical diagnosis and visual assessment of experimental intrauterine therapy in mares.

Intrauterine fibroscopy was used in the clinical evaluation of 40 mares with established histories of subfertility. The average age of the mares was 12.2 years with a 2.8-year interval from last foaling in multiparous mares. Transluminal adhesions, endometrial cysts, diffuse fibrosis, fluid accumulation or myometrial tumours were found in 26 mares. When compared to other techniques, fibroscopy did not seem to be superior to uterine biopsy but had some advantage over rectal palpation as a single diagnostic technique. Only 3 mares failed to exhibit pathological findings when all 3 techniques were used. A second study was conducted to examine visually the effect of infusing various antibiotics and disinfectants into the uteri of clinically normal dioestrous mares. Fibre-optic examinations were performed before and after infusion of 3 mares/treatment. No gross pathological changes were seen 3 days after infusion of potassium penicillin, chloramphenicol succinate or a soluble oxytetracycline powder in a dextrose base. Lugol's solution caused severe inflammation, fibrin deposition, and ulceration of the endometrium. Ampicillin resulted in a white precipitate which adhered to the the endometrium for 10 days after treatment.

Animals↗