Intraspecies genetic variability of Ornithobacterium rhinotracheale in commercial birds in Peru

Strains of the bacterium Ornithobacterium rhinotracheale (ORT), a causal agent of respiratory diseases in birds, were microbiologically isolated, identified, and molecularly characterized. Blood-enriched culture media and biochemistry tests were used for microbiologic identification. Polymerase chain reaction (PCR) and repetitive extragenic palindromic PCR (rep-PCR) techniques were used for molecular identification and characterization, respectively, of the microorganism. ORT strains were isolated in enriched media from the trachea and air sacs of broilers, breeders, and layers from several geographic zones of Peru. Of the original 75 strains isolated from 75 clinical samples from which ORT was recovered during 1998-2000, 25 were selected for further study based on ORT as the primary pathogenic isolate (no other pathogens were detected). Selected isolates were molecularly identified and characterized by PCR using specific primers designed from the conserved zones of the 16S ribosomal genes. Primers used for the identification of ORT produced a specific fragment of 784 base pair (bp), which did not appear in Haemophilus paragallinarum or Pasteurella multocida, microorganisms with similar morphologic and biochemical characteristics that produce dinical signs identical to those of ORT. All 25 strains of ORT tested with rep-PCR had a genetic profile similar to that of ORT American Type Culture Collection 51463, indicating the presence of only one genotype in the ORT strains studied.     

Experimental use of polyamide bands in combination with intramedullary pinning for repair of oblique femoral fractures in rabbits

OBJECTIVE: To evaluate the use of polyamide bands, manufactured for securing electrical cables, for repair of oblique femoral fractures in rabbits. STUDY DESIGN: Experimental study. ANIMALS: Twelve nulliparous, 21-25-week-old, California female rabbits. METHODS: Rabbits were divided into 3 groups (n=4) and studied for 14, 28, or 56 days. A Z-shaped mid-diaphyseal femoral osteotomy was repaired with a 2.5 mm intramedullary pin and a polyamide 6.6 cerclage band. Healing was evaluated at intervals by physical examination, limb use, femoral radiographs, and callus histology. RESULTS: Rabbits had early limb use with good wound healing. From the 1st day, movement of the hip and stifle joints was satisfactory. Radiographically, fractures were healed at 28 days. Histologically, there was no foreign body reaction and bone healing was normal. CONCLUSION: Nylon cerclage band application was accomplished easily, maintained reduction, and resulted in good healing and limb use. CLINICAL RELEVANCE: Sterilized nylon bands, manufactured for electrical use, can be used for cerclage in rabbits.     

The central retinal artery and regression of the hyaloid artery in perinatal cattle

The arterial supply to the retina and lens of 10 fetal, 10 neonatal and four adult Zavot-bred cattle of both sexes was studied macroscopically and by stereoscopic microscopy by means of vascular perfusion with latex, giving special emphasis on the hyaloid artery. The central retinal artery ramified in four major retinal arterioles, which formed a compact network throughout the retina (holangiotic or euangiotic pattern). The hyaloid artery was patent in all fetal stages and extended through the vitreous cavity of the eye to the caudal surface of the capsule of the lens. Atrophy of the hyaloid artery began immediately after birth and was completed on day 17 after parturition. No remnant of the hyaloid artery in the vitreous cavity was observed in the adult cattle examined at stereoscopic microscopic level.     

The developmental pattern of c-fos expression in the rat thalamus following open-field stress stimulation

The thalamic nuclei with their defined set of input-output connections are the primary channel for information flow to the cerebral cortex. Several data suggest that neurons of that area are involved in the response to various aversive stimulations. However the pattern of activation seems to depend on the stress model as well as the stage of maturation. In the present study we would like to check which nuclei of the thalamus show expression of c-fos in the response to the "open field test", and how this response pattern changes during the maturation process. 30 rats of age ranged from P0 to P120 (P-postnatal day) were studied. The experimental group was exposed to the "open field test" for 10 minutes. After perfusion and fixation, brains were cut and stained for c-fos with immunohistochemical method. Our results showed that during development the pattern of c-fos activity in the thalamic nuclei after stress stimulation undergoes significant changes. Distinct c-fos expression was observed in the paraventricular nucleus, intergeniculate leaflet and ventral lateral geniculate nucleus. These findings suggest that these nuclei may play a direct role in the stress reaction involved in the response to the "open field test".     

Analysis of the right ventricular function in the exercising horse: use of the Fourier Transform

The objective of this study was to develop and test a technique to allow dynamic cardiac function to be studied during exercise in the horse. Blood pressure waveforms in the exercising horse are difficult to interpret because of the large influence of stride and respiration. A method has been devised to study dynamic right ventricular variables during high-speed exercise in the horse. A Fast Fourier Transform was performed on the digitised pressure waveforms and the frequency components associated with stride and respiration were removed. An inverse Fourier Transform was then performed to generate a time-domain pressure signal. Several dynamic right ventricular variables were calculated using the derived signal. Various parameters associated with removing frequencies from the frequency-domain pressure signal were changed to determine their influence on the variables. Most of the variables were not sensitive to these parameters. When compared during separate exercise bouts, some variables differed among runs, while others were not significantly different. Using the signal separation technique described here, right ventricular function of an exercising horse can be critically analysed.     

Long-term EKG in dogs: comparison between a computerized system and visual arrhythmia analysis]

Based on results of holter ecg recordings taken from 38 dogs the computerized analyses system turned out as method not exactly valuing the frequency and sensitivity of arrhythmias. Despite there was a significant correlation between the computerized and visual arrhythmia analysis for ventricular respectively supraventricular premature beats, in individual cases there was an important aberration between the particular values.     

Regulation of atrial fibrillation in horses with oral quinidine sulfate. Discussion of the disease picture in a typical case

Atrial fibrillation is a disorder of cardiac rhythmicity, and its importance in the horse depends on the underlying cause and the function of the horse. Before the decision is taken to start treatment, it has first to be ascertained whether treatment is worthwhile and whether the horse is an appropriate candidate for treatment. This article gives a short overview of current opinion on the cause and treatment of atrial fibrillation in the horse. The most used treatment at the moment, oral chinidine sulphate, is discussed. The hemodynamic consequences of atrial fibrillation and the response of a patient to treatment with chinidine sulphate are also discussed.