Effects of small and large face masks and translaryngeal and tracheostomy intubation on ventilation, upper-airway dead space, and arterial blood gases

Pulmonary function was examined in pentobarbital-anesthetized dogs that were spontaneously breathing through a large poorly fitted face mask, a small snug-fitted face mask, an endotracheal tube, and a tracheostomy tube. Increasing upper-airway dead space volumes were associated with higher minute ventilation and faster breathing rates. Minute and tidal alveolar ventilation, calculated ideal alveolar oxygen, alveolar-arterial oxygen gradient, venous admixture, arterial pH and blood gases, cardiac output, and systemic and pulmonary arterial blood pressure were not changed. The functional dead space of each mask was considerably less than that measured by water displacement. The small mask only slightly increased, and the endotracheal tube slightly decreased, the dead space estimated for a nasally breathing healthy dog.     

Nonweightbearing lameness secondary to synovial sarcoma in a young dog

Synovial sarcoma was diagnosed in the right carpus of a 2 1/2-year-old mixed-breed dog. The dog had developed a right forelimb lameness before one year of age. The lameness was progressive for nearly 2 years, resulting in severe disuse atrophy of the right forelimb musculature and pronounced osteopenia. A definitive diagnosis was not made until the dog was referred after 2 years of conservative treatment was ineffectual. Right forelimb amputation was done and the dog survived an additional 15 months. The protracted clinical course before definitive diagnosis underscores the need for aggressive pursuit of a diagnosis when conservative treatment of a lameness is not efficacious.     

Dietary sodium bicarbonate as a treatment for exertional rhabdomyolysis in a horse

A 3-year-old mare repeatedly had clinical signs of rhabdomyolysis on mild exertion. Serum creatine kinase and aspartate transaminase activities were high at rest. Responses to dietary sodium bicarbonate were tested through 7 alternating periods of supplementation of a basal ration of timothy hay and oats. Physical signs; venous blood pH and gases; blood glucose and lactate; serum electrolytes, enzymes, and creatinine; and urine pH were monitored before and after exercise. Dietary sodium bicarbonate raised resting venous blood pH and bicarbonate slightly and significantly increased urine pH from pH 7.46 to 8.2 (P less than 0.001). An exercise test included 5 minutes at the walk followed by 20 minutes at the trot. The exercise induced gait stiffness, muscle fasciculations, and muscle induration when the diet was not supplemented, but not when it was supplemented with sodium bicarbonate. Myoglobin was present in 16 of 21 urine samples after exercise during nonsupplemented periods, but only in 3 of 28 urine samples during supplemented periods (P less than 0.0001). Bicarbonate supplementation significantly decreased the responses of blood lactic acid, serum creatine kinase, and aspartate transaminase to exercise. Supplementation of the diet was associated with higher venous blood pH and bicarbonate ion concentrations throughout exercise. Dietary sodium bicarbonate apparently mitigated or prevented physical, chemical, and enzymatic characteristics of exertional rhabdomyolysis in this mare, possibly through its enhancement of buffering capacity in muscle tissue fluids.     

The effect of feeding pellets of different types of roughage on the incidence of lesions in the abomasum of veal calves

Pellets of three types of roughage were fed to veal calves, to determine their effect on the frequency of lesions (erosions or ulcers) of the abomasal mucosa. The number was increased in the calves fed roughage. Pellets produced from corn silage caused a greater number of lesions than pellets produced from barley straw or lucerne hay. It is concluded that the nature of the roughage plays a role in the pathogenesis of abomasal lesions.     

Effect of electroimmobilisation on ovine plasma concentrations of beta-endorphin/beta-lipotrophin, cortisol and prolactin

The effect of electroimmobilisation on the plasma concentrations of beta-endorphin/beta-lipotrophin (beta-EP/beta-LPH), cortisol and prolactin (PRL) has been assessed in sheep. Serial blood samples were collected from control and electroimmobilised animals during the first and fourth of a series of four repeated treatments over two days. After electroimmobilisation the mean (+/- SEM) plasma concentrations of beta-EP/beta-LPH increased significantly from 132 +/- 19 pg ml-1 to 545 +/- 111 pg ml-1; the plasma concentrations of cortisol also increased significantly from 22.3 +/- 3.5 ng ml-1 to 108.0 +/- 12.9 ng ml-1. There was no significant change in plasma PRL concentrations after electroimmobilisation and also no significant difference between the plasma concentrations of PRL in the control and electroimmobilised animals. There was no significant difference between the effects of the first and fourth exposure to electroimmobilisation on the plasma concentrations of beta-EP/beta-LPH, cortisol and PRL. These results suggest that the endocrine response to electroimmobilisation may be specific to the pituitary-adrenal axis.     

Surface proteins of Breda virus

The serotypes 1 and 2 of Breda virus from feces of experimentally infected gnotobiotic calves were studied with respect to their sedimentation and density properties in sucrose gradients and their structural polypeptides; Berne virus, the proposed prototype of the new family Toroviridae, was included for comparison. After Breda-1 virus had been stored at 4 C for a prolonged period, it showed a heterogeneous sedimentation behavior (480 to 520 Svedberg units [S]) and density (1.18 to 1.21 g/ml) indicative of its poor state of preservation. In contrast, freshly prepared Breda-2 virus sedimented at 350 S and showed a buoyant density of 1.18 g/ml; these values compare well with those of Berne virus (400 S and 1.16 g/ml, respectively). Efficient purification of the Breda viruses could be achieved by a 2-step method, involving pelleting by ultracentrifugation followed by isokinetic and isopyknic sucrose gradient centrifugation. Radioiodinated purified virus showed polypeptides with apparent molecular weights of 105,000, 85,000 37,000, and 20,000; another labeled protein of 65,000 D is of doubtful virus specificity. Mouse immune serum raised against Breda-2 virus recognized the polypeptides of the homologous virus and the 2 highest molecular weight proteins of Breda 1 virus in radioimmune precipitation. The same serum inhibited hemagglutination of the heterologous serotype to a low, but significant, degree and efficiently neutralized the infectivity of Berne virus. These observations are taken as indications that the 105,000- and 85,000-D polypeptides represent surface structures of torovirions, probably peplomeric proteins.     

Primary isolation and identification of avian rotaviruses from turkeys exhibiting signs of clinical enteritis in a continuous MA 104 cell line

Avian rotaviruses were isolated from turkeys with enteritis using MA 104 cell line. MA 104 cells were suitable for primary isolation and propagation of avian rotaviruses. Trypsin appeared essential for the enhancement of infectivity and the occurrence of cytopathic effect (CPE). Serum neutralization (SN), electron microscopy (EM), and analysis of genomic RNA were done to identify and confirm the identity of rotaviruses. Electrophoretic migration patterns of genomic RNA from avian rotaviruses were examined, and they were compared with those from mammalian rotaviruses. The migration patterns differed between these groups.     

Tetrodotoxin- and resiniferatoxin-induced changes in paracervical ganglion ChAT- and nNOS-IR neurons supplying the urinary bladder in female pigs

The aim of the present study was to establish the effect of intravesical administration of resiniferatoxin (RTX) and tetrodotoxin (TTX) on the chemical coding of paracervical ganglion (PCG) neurons supplying the urinary bladder in the pig. In order to identify the PCG neurons innervating the bladder, retrograde tracer Fast Blue was injected into the bladder wall prior to intravesical RTX or TTX administration. Consequent application of immunocytochemical methods revealed that in the control group 76.82% of Fast Blue positive PCG neurons contain nitric oxide synthetase (nNOS), and 66.92% contain acetylcholine transferase (ChAT). Intravesical infusion of RTX resulted in a reduction of the nNOS-IR neurons to 57.74% and ChAT-IR to 57.05%. Alternative administration of TTX induced an increase of nNOS-IR neurons up to 79.29% and a reduction of the ChAT-IR population down to 3.73% of the Fast Blue positive PCG cells. Our data show that both neurotoxins affect the chemical coding of PCG cells supplying the porcine urinary bladder, but the effects of their action are different. Moreover, these results shed light on the possible involvement of NO-ergic and cholinergic neurons in the mechanisms of therapeutic action exerted by RTX and TTX in curing the overactive bladder disorder.