Age-related changes in porcine corticosteroid-binding globulin (pCBG) as determined by an enzyme-linked immunosorbent assay

The objectives of this study were to develop an assay for the direct measure of porcine corticosteroid-binding globulin (pCBG) and to confirm age-related changes in plasma pCBG concentration. Isolation and purification of pCBG from plasma was performed by affinity chromatography and HPLC–DEAE anion exchange techniques. Analysis by SDS–PAGE revealed two polypeptides (54 and 59 kDa) having similar amino acid homology (>50%) to previously reported sequences of seven mammalian species for the first 33 amino acids. Porcine CBG (20 ng/well) was immobilized to microtiter plates and standards or samples added along with rabbit antiserum developed against the purified pCBG. Goat anti-rabbit IgG-alkaline phosphatase conjugate was added followed by p-NPP substrate. The resultant color development was read at 405 nm. Intra- and interassay coefficients of variation (n=26) of a pooled sample were 10 and 15%, respectively. Age-related changes (P<0.001) in plasma pCBG concentration (n=203) from day 3 through 168 of age confirmed that, in the pig, changes seen in the percent distribution of cortisol among protein bound and free forms around day 28 of age are associated with an increase in CBG concentration.     

Population pharmacokinetics of marbofloxacin in aqueous humor after intravenous administration in dogs

OBJECTIVE: To evaluate, by use of population pharmacokinetics, the disposition of marbofloxacin in the aqueous humor after IV administration in dogs and identify its potential usefulness in the prophylaxis and treatment of intraocular infection. ANIMALS: 63 dogs. METHODS: Dogs received a single dose of marbofloxacin (2 mg x kg(-1), IV) at various time intervals before cataract surgery. Aqueous humor and blood samples were collected at the beginning of surgery. Marbofloxacin concentrations were measured by high-pressure liquid chromatography. Data were analyzed with a nonlinear mixed-effect model and, by use of population pharmacokinetic parameters, the time course of aqueous humor concentration was simulated for single doses of 3, 4, and 5.5 mg x kg(-1) IV. Pharmacodynamic surrogate markers and measured aqueous humor concentrations were used to predict in vivo antimicrobial activity. RESULTS: A maximum marbofloxacin concentration of 0.41 +/- 0.17 microg x mL(-1) was reached in the aqueous humor 3.5 hours after IV administration. In the post-distributive phase, marbofloxacin disappeared from aqueous humor with a half-life of 780 minutes. The percentage penetration into the aqueous humor was 38%. Predictors of antimicrobial effects of marbofloxacin (2 mg x kg(-1), IV) indicated that growth of the enterobacteriaceae and certain staphylococcal species would be inhibited in the aqueous humor. Marbofloxacin administered IV at a dose of 5.5 mg x kg(-1) would be predicted to inhibit growth of Pseudomonas aeruginosa and all strains of staphylococci but would not eradicate streptococcal infections. CONCLUSIONS AND CLINICAL RELEVANCE: Marbofloxacin administered IV can penetrate the aqueous humor of canine eyes and may be suitable for prophylaxis or treatment of certain anterior chamber infections.     

Follicular and oocyte development in gilts of different age

The aim of the present study was to estimate follicular and oocyte development of the same gilts in three phases of their reproductive life--prepuberal gilt (6 months old), cycling gilt (9.5 months old) and primiparous sow. Follicular development was induced by injections of 1000 IU PMSG followed by 500 IU hCG 72 h later. Cumulus-oocyte-complexes (COCs) were recovered from preovulatory follicles of the left ovary, and follicular fluid (FF) from the right ovary always 34 h after hCG by endoscopy. Altogether, 19 gilts were used in the prepuberal (P) and cycling (C) trials and 12 of them in the primiparous trial (S). Altogether 168, 190 and 82 follicles were aspirated from the left ovary and 106, 125 and 42 COCs recovered (recovery rate 60.5 +/- 26.9, 62.7 +/- 20.9 and 52.9 +/- 21.8%). The average number of follicles was higher in C compared to P (19.7 +/- 6.8 vs. 15.7 +/- 6.8, p = 0.06) and to S (14.2 +/- 4.0, p < 0.05), respectively. More uniform expanded COCs were aspirated from prepuberal and cycling gilts as compared to sows (89.7 and 78.4% vs. 46.3%, p < 0.05). Furthermore, the meiotic configuration in oocytes differed (p < 0.05) between these groups (55.5 and 61.7% vs. 0% Telo 1/Meta 2). Concentrations of progesterone in FF decreased (p < 0.05) from 590.0 +/- 333.6 (P) to 249.1 +/- 72.6 (C) and 161.4 +/- 75.2 ng/ml (S). FF concentrations of oestradiol-17 beta were different between gilts and sows (9.3 +/- 2.9, 21.9 +/- 10.6 and 94.0 +/- 15.9 pg/ml, p < 0.05). The progesterone/oestradiol ratio was 72.1, 15.2 and 4.7. Results indicate a different follicular and oocyte development during the investigated lifetime periods. Cycling gilts should preferably be used in IVF and breeding programs. The lower reproductive potential of primiparous sows is taken into consideration at breeding. Prediction of lifetime performance based on individual ovarian reaction of prepuberal gilts is unsuitable.     

Long-term outcome of horses with a slab fracture of the central or third tarsal bone treated conservatively: 25 cases (1976-1993)

OBJECTIVE: To determine clinical features of horses with a slab fracture of the central or third tarsal bone and to report outcome of horses in which treatment did not include surgery. DESIGN: Retrospective study. ANIMALS: 25 horses (14 Standardbreds, 6 Thoroughbreds, 5 Quarter Horses). PROCEDURE: Medical records of horses with a slab fracture of the central (n = 9) or third (16) tarsal bone were reviewed. Only horses for which treatment consisted of confinement to a stall were included in this study. Clinical features and radiographic findings were recorded and summarized. Outcome was determined for racing breeds by obtaining official lifetime race results. Outcome for Quarter Horses was determined by phone survey of the owners. RESULTS: 16 (64%) horses had a successful outcome. Ten of 14 (71%) Standardbreds and 2 of 6 Thoroughbreds returned to racing and started at least 5 races after injury. Four of 5 Quarter Horses for which follow-up information was available successfully returned to their previous activity. Sex, age, limb affected, or gait was not associated with final outcome. Percentage of racehorses with central tarsal bone fractures that had a successful outcome (2/7) was significantly less than percentage with third tarsal bone fractures that did (10/13). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that enforced rest without surgical fixation can be an effective therapeutic option for horses with a slab fracture of the central or third tarsal bone, even if athletic function is expected.