The bioavailability and disposition kinetics of genistein in cats

The absorption and disposition kinetics of the soy isoflavone genistein were determined in cats (n = 6). An oral dose of 100 mg/kg was administered, which has previously been demonstrated to be the minimum oral estrogenic dose, and was administered intravenously at a dose of 20 mg/kg, being the largest practical dose that could be safely administered. Plasma free, and total (conjugated + free) genistein concentrations were determined by HPLC following organic extraction. Noncompartmental analysis revealed a half-life of 21.67 +/- 7.9 h (free) and 9.95 +/- 2.7 h (conjugated), volume of distribution 31.94 +/- 10.38 L/kg (free) and 11.82 +/- 3.96 L/kg (conjugated) following intravenous administration. Following oral administration the half-lives were determined to be 17 +/- 4.8 h (free) and 8.56 +/- 4.65 h (conjugated), with tmax = 4.4 +/- 0.6 h (free) and 4.42 +/- 0.99 h (conjugated), and Cmax = 0.276 +/- 0.1 microg/mL (free) and 6.24 +/- 6.58 microg/mL (conjugated). Oral bioavailabilities were 1.379 +/- 0.9% (free) and 29.85 +/- 22.61% (conjugated). The ratio of total:free genistein ranged from 25.9 to 5.5. Poor oral absorption and efficient conjugation explain the low bioavailability of free genistein. Accumulation of genistein in peripheral lipophilic compartments may occur.     

Salmonella enterica infections in Spanish swine fattening units

The present study is the first conducted in Spain to estimate the bacteriological herd prevalence of Salmonella enterica in fattening units and to describe the Salmonella serovar diversity on these farms using a sample representative of the entire swine population. For this purpose, 10 faecal samples were collected from 10 different pens containing pigs close to market weight in a total of 232 fattening units. Total sample size was proportionally distributed according to the fattener census in each of the regions of the country and all the samples were examined by culture of 25 g of faecal material. One hundred (43.1%) farms had at least one Salmonella-positive sample (95% CI: 37-49.1%). Salmonella enterica was detected in 290 (12.5%) pooled faecal floor samples (95% CI: 11.2-13.8%). The apparent herd prevalence of salmonellosis was similar among multi-site, finishing and farrow to finish farms. Overall, 24 different serovars were identified, with S. Typhimurium, S. Rissen and S. Derby being the most common both at herd and sample level. Results of phage typing were available for the 91 isolates of S. Typhimurium. A total number of 10 different phage types were identified, with DT 193 being the most frequent. Phage types DT 104, DT 104b and DT U302, which have been associated with several multi-resistant patterns, accounted for 23% and 29% of the Typhimurium total isolates or Typhimurium infected farms respectively.     

Primary intraocular primitive neuroectodermal tumor (retinoblastoma) causing unilateral blindness in a gelding

A 14-year-old gray gelding was presented for investigation of a visible, pale-colored ocular mass in the right eye. An intraocular mass was identified clinically and ultrasonographically as originating from the superior nasal quadrant of the ciliary body and retina. The mass occupied the majority of the vitreous chamber and some of the superior anterior chamber of the eye. The affected eye was blind. Following exenteration, a primary intraocular primitive neuroectodermal tumor (i.e. a retinoblastoma/medulloepithelioma), a rarely described intraocular mass in adult horses, was identified by pathologic examination. The gelding returned to normal use following a short recovery period.     

Development and validation of the maximal electro-shock seizure model in dogs

The development and validation of the maximal electro-shock (MES) model using phenobarbital (Pb) as the positive control is described. This approach builds on previous work in rodent model systems, and has been adapted to dogs as a tool for pharmaceutical dose selection. Dogs, like rodents, exhibit generalized convulsions which manifest as progressive clinical signs in a dose (electrical current) dependent fashion. At the limit (300 mA, 200 msec) animals underwent clonic-tonic convulsions consistent with complete generalized (Grand Mal) seizures with a grade 3 clinical score (CS) and a menace response time of 98.5 +/- 24.4 sec (n = 8). Pretreatment of animals with Pb at 3, 10, and 30 mg/kg, in a 4-by-4 complete block crossover design (Latin-Square), resulted in a dose-dependant reduction in CS and menace response time. Estimates of plasma Pb concentration taken prior to MES induction showed a similar dose-dependent reduction in CS and menace response time with concentration. Using a cumulative logistic regression model, a predicted 50% probability of a CS = 1 was approximately 11.4 mg/kg. In addition, plasma Pb concentrations predicted a 50% probability of a CS = 1 occurs at plasma Pb concentration of approximately 16.0 mug/mL. Combined these data suggest that MES is a useful model for evaluating generalized convulsions in canines and may provide a tool for dose selection of novel pharmaceutical compounds.     

Potential use of lymphocyte blastogenic responses in diagnosis of bovine tuberculosis

A comparison of in vitro lymphocyte responses and delayed type tuberculin skin test responses was made in an animal experimentally exposed to a Mycobacterium bovis-infected animal and in cattle naturally infected with M. bovis. Tuberculin skin tests did not suppress in vitro lymphocyte responses to M. bovis PPD and to M. avium PPD tuberculin. The whole blood test used in these studies provided for considerable savings in time as compared to use of purified lymphocytes for evaluating in vitro cellular responses. Variations in the responsiveness of lymphocytes to specific mycobacterial antigens was observed, therefore, it is recommended that profiles be established using three or more tests conducted at 14-day intervals.     

Efficacy of two dichlorvos formulations against larval and adult Hyostrongylus rubidus in swine.

Coated (V-13) and uncoated (V-22) formulations of dichlorvos were used to treat experimentally established Hyostrongylus rubidus infections of pigs at intervals after exposure to infective larvae. Both dichlorvos formulations were efficacious against the adult stomach worm H rubidus, but showed little or no activity against 5- or 15-day-old worms. Neither formulation was as effective against H rubidus in sows as in barrows and gilts.     

Cardiopulmonary effects of fentanyl-droperidol, nitrous oxide, and atropine sulfate in dogs.

The cardiopulmonary effects of droperidol-fentanyl, nitrous oxide, and atropine were evaluated in 12 adult male Beagle dogs. All dogs were surgically instrumented with a cardiac output thermistor and arterial and venous catheters and were prepared with a chronic tracheostomy. Each dog was used as its own control, and data obtained when dogs were nonanesthetized and nonmedicated were compared with data recorded after the test drugs were administered. The dogs were randomly allotted to 3 groups of 4 dogs each. Group I dogs were given droperidol-fentanyl alone intravenously (IV); group II dogs were given droperidol-fentanyl IV with 67% nitrous oxide; and group III dogs were given atropine sulfate intramuscularly followed by droperidol-fentanyl IV with 67% nitrous oxide. Minute volume was decreased in the 3 groups of dogs for 3 to 5 minutes after droperidol-fentanyl was injected. This resulted in respiratory and metabolic acidosis in all dogs, as indicated by increased arterial carbon dioxide tension, decreased pH, and increased base deficit. In addition, droperidol-fentanyl given alone caused a decrease in systolic pressure and a slight decrease in heart rate. Group 1 dogs were sensitive to auditory stimulation. Cardiovascular changes were not seen when nitrous oxide was added; however, analgesia and muscle relaxation were improved. Premedication with atropine sulfate resulted in increased cardiac output, heart rate, and diastolic pressure, and subsequent administration of droperidol-fentanyl with nitrous oxide caused a transient increase in mean arterial and systolic pressure. This last anesthetic regimen, along with assisted or controlled respiration, seems to provide an excellent anesthetic state with minimal cardiopulmonary depression.     

Periovulatory changes in peripheral plasma progesterone and estrogen concentrations in the mare.

Concentrations of progesterone and estrogen were measured in peripheral blood plasma samples from mares around the time of ovulation. Samples were collected every 2 hours from 36 hours before, to 26 hours after, ovulation and assayed by radioimmunoassay. Progesterone concentrations were between 60 and 100 pg/ml for the period 24 hours before ovulation through 8 hours after ovulation. By 10 hours after ovulation, concentrations increased to 140 pg/ml and, by 26 hours after ovulation, reached 346 pg/ml. Plasma estrogen concentrations did not change significantly throughout the same period.