Efficacies of trimethoprim-sulfadiazine and gentamicin sulfate in the treatment of fibrinous peritonitis in rats

Trimethoprim-sulfadiazine and gentamicin sulfate decreased early mortality in an established model of fibrinous peritonitis in the rat. Both drugs failed to prevent abscess formation, indicating that there was poor penetration of fibrin; however, they significantly decreased (P less than 0.01) bacterial numbers in residual abscesses. The colony count per abscess in the gentamicin sulfate-treated group was significantly lower (P less than 0.01) than that in the trimethoprim-sulfadiazine-treated group.     

Anesthetic management of ruminants and swine with selected pathophysiologic alterations

Surgical diseases induce pathophysiologic alterations in ruminants and swine that are often of critical importance in the perioperative period. Circulation and ventilation may be severely compromised. Alterations in acid-base balance, fluids, and electrolytes should be anticipated, identified, and corrected. Also discussed is the selection of appropriate anesthetic techniques and supportive therapy based upon the patient's physiologic status and surgical requirements.     

Ultrastructural and functional correlates of increased luteinizing hormone synthesis and secretion in castrated male mice.

The changes in the ultrastructure of gonadotrops and in the plasma levels of LH were studied three, five, seven, ten, twenty and forty days after castration in adult male mice. Gonadotrops in sham operated animals contained numerous granules and moderately developed synthetic organelles. Castration induced mobilization of the secretory granules at three days, and degranulation of gonadotrops and a hypertrophy of the synthetic organelles at seven days. By ten days after castration gonadotrops were greatly enlarged, while in addition at forty days they frequently contained large cytoplasmic vesicles filled with lipid-like material. These changes were paralleled by an initial three fold increase in serum LH three days after castration, and a further ten fold increase in the levels of the hormone forty days after castration. In conclusion, the castration-induced morphologic changes in gonadotrops correlate well with increased release of LH. The subtle differences in the control of timing of LH secretion in mice and rats are discussed. A trans-cytoplasmic route for rapid transport of gonadotropic hormones in the mouse is postulated, and the significance of cytoplasmic vesicles in the castrate discussed.     

Pharmacokinetics of imipenem-cilastatin following intravenous administration in healthy adult horses

In two studies, six healthy adult horses were given imipenem-cilastatin by slow intravenous (i.v.) infusion at an imipenem dosage of 10 mg/kg (study 1) and 20 mg/kg (study 2). The same horses were used in each dosage schedule, with a 2-week washout period between studies. In each dosage group, serial blood and synovial fluid samples were collected for 6 h after completion of the infusion. HPLC was used to determine the imipenem concentration in all samples. Imipenem was well tolerated by all horses at both dosages; no adverse effects were noted during the study period or during the 24-hour postinfusion observation period. The pharmacokinetic profiles of imipenem in the plasma and synovial fluid indicate that an imipenem dosage of 10-20 mg/kg by slow i.v. infusion q6h (every 6 h) is appropriate for most susceptible pathogens.     

Disseminated Acanthamoeba sp. infection in a dog

Several species of free-living amoebae can cause encephalomyelitis in animals and humans. Disseminated acanthamoebiasis was diagnosed in pyogranulomatous lesions in brain, thyroid, pancreas, heart, lymph nodes, and kidney of a one-year-old dog. Acanthamoeba sp. was identified in canine tissues by conventional histology, by immunofluorescence, by cultivation of the parasite from the brain of the dog that had been stored at -70 degrees C for two months, and by PCR. The sequence obtained from the PCR product from the amoeba from the dog was compared to other sequences in the Acanthamoeba sp. ribosomal DNA database and was determined to be genotype T1, associated with other isolates of Acanthamoeba obtained from granulomatous amebic encephalitis infections in humans.     

Evaluation of EEG based determination of unconsciousness vs. loss of posture in broilers

Evaluation of the loss of consciousness in poultry is an essential component in evaluating bird welfare under a variety of situations and applications. Many current approaches to evaluating loss of consciousness are qualitative and require observation of the bird. This study outlines a quantitative method for determining the point at which a bird loses consciousness. In this study, commercial broilers were individually anesthetized and the brain activity recorded as the bird became unconscious. A wireless EEG transmitter was surgically implanted and the bird anesthetized after a 24-48 h recovery. Each bird was monitored during treatment with isoflurane anesthesia and EEG data was evaluated using a frequency based approach. The alpha/delta (A/D) ratio and loss of posture (LOP) were used to determine the point at which the birds went unconscious. There was no statistically significant difference between time to unconsciousness as measured by A/D ratio or LOP.     

Design of bioelectronic interfaces by exploiting hinge-bending motions in proteins

We report a flexible strategy for transducing ligand-binding events into electrochemical responses for a wide variety of proteins. The method exploits ligand-mediated hinge-bending motions, intrinsic to the bacterial periplasmic binding protein superfamily, to establish allosterically controlled interactions between electrode surfaces and redox-active, Ru(II)-labeled proteins. This approach allows the development of protein-based bioelectronic interfaces that respond to a diverse set of analytes. Families of these interfaces can be generated either by exploiting natural binding diversity within the superfamily or by reengineering the specificity of individual proteins. These proteins may have numerous medical, environmental, and defense applications.     

Differences among restriction endonuclease DNA fingerprints of Pennsylvania field isolates, vaccine strains, and challenge strains of infectious laryngotracheitis virus.

Restriction endonuclease fingerprints of infectious laryngotracheitis virus (ILTV) DNA from 13 Pennsylvania field isolates, embryo-propagated and tissue-culture-propagated vaccine strains, and three reference strains were compared. These comparisons were made to evaluate the possible contribution of mutation of ILTV vaccine strains to recent outbreaks of infectious laryngotracheitis (ILT) in Pennsylvania. Six different restriction enzymes were used to generate the fingerprints. Differences in DNA banding patterns were revealed between the currently used ILTV vaccine strains and six of the 13 field isolates. Even greater DNA banding pattern differences were found between the older ILTV reference strains and the vaccine strains. The ILTV DNA fingerprints generated in the present study suggest that at least five different strains of ILTV have contributed to the outbreaks of ILT that have occurred since 1987 in Pennsylvania.