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Biomedical subjects

J B Stevens

Publications and source records attributed to J B Stevens.

At least 73 records · Page 4Linked to original sources
PubMed1981

Acute hepatic necrosis associated with the administration of mebendazole to dogs.

Mebendazole was administered to 7 adult Dachshunds and 2 adult Doberman Pinschers at 6-month intervals for routine parasite control. Two weeks after the 1st treatment, a 3-year-old Dachshund died of acute hepatic failure. Approximately 2 weeks following the 2nd treatment, two 5-year-old Dachshunds and one 3-year-old Dachshund had evidence of acute hepatic necrosis; 1 of these dogs died of fulminant hepatic failure. Typical clinical signs in affected dogs included anorexia, depression, vomiting, icterus, and hemorrhagic diarrhea. Two additional Dachshunds had biochemical evidence of hepatic dysfunction, ie. high serum alanine aminotransferase and serum alkaline phosphatase activities. One Dachshund and 2 Doberman Pinschers had no clinical or laboratory evidence of hepatic disease.

Acute Disease↗
PubMed1981

Mineral composition of urinary calculi from miniature schnauzer dogs.

The mineral composition of 150 calculi from the urinary tracts of Miniature Schnauzer dogs was determined by qualitative and quantitative methods. Struvite was the predominant mineral in 92% of the calculi. Other calculi contained predominantly apatite, calcium oxalate, ammonium urate, or silica. Most calculi were from the urinary bladder or urethra, or both. Four were from the renal pelves. Struvite calculi were more frequently encountered in females than males. The mean age of the dogs at the time of detection of calculi was 4.8 years. Qualitative analysis failed to detect some minerals that were identified by quantitative analysis.

Animals↗
PubMed1981

Canine and feline urinalysis: value of macroscopic and microscopic examinations.

A retrospective survey of complete urinalyses performed on dogs and cats hospitalized at the University of Minnesota Veterinary Teaching Hospital was performed to determine the frequency of abnormal findings in urine sediment, compared with normal and abnormal macroscopic findings. One thousand consecutive urine samples collected from dogs and 1,000 consecutive urine samples collected from cats were studied. Results indicated that failure to examine urine sediment of macroscopically normal samples would have yielded false-negative results in 16.5% of the canine patients and 5.7% of the feline patients. Microscopic findings in macroscopically normal canine samples consisted primarily of pyuria and bacteriuria, whereas in cats they consisted of hematuria and bacteriuria. Microscopic abnormalities were detected in almost 50% of the canine and feline samples with macroscopic abnormalities. The results of this evaluation confirm the value of routine microscopic examination of urine sediment as a component of complete urinalysis.

Animals↗
PubMed1981

Blood concentrations of beta hydroxybutyrate in clinically normal Holstein-Friesian herds and in those with a high prevalence of clinical ketosis.

Statistical parameters necessary for the comparison of herd blood beta hydroxybutyrate (HB) concentration means with HB concentrations in the general population were determined in 11 clinically normal herds of Holstein-Friesian cows. These parameters were then used to compare clinically normal cows from 2 Holstein-Friesian herds experiencing a high prevalence of clinical ketosis with the normal population. Blood HB concentration means were compared with plasma glucose concentration means for their relative value as predictors of clinical ketosis prevalence within a herd. Blood HB concentration values were distributed approximately log normal and were directly related to amount of milk production. Herds with a high prevalence of clinical ketosis had blood HB log means higher (P less than 0.01) and glucose means lower (P less than 0.05) than did the normal population. Herd blood HB log means should be determined on 7 or more animals within specified production groups. When these means exceed the normal population log mean by more than 1 SD, susceptible cows in the herd may be at increased risk for the development of clinical ketosis. Blood HB log means may be of greater value than are plasma glucose concentration means for the prediction of herd ketosis prevalence.

3-Hydroxybutyric Acid↗
PubMed1981

Influence of ration composition and energy balance on blood beta-hydroxybutyrate (ketone) and plasma glucose concentrations of dairy cows in early lactation.

The effect of ration composition, with respect to concentrate, crude protein, and methionine hydroxyanalog content, on blood beta-hydroxybutyrate and plasma glucose concentrations was assessed in Holstein cows every 2 weeks over the first 6 weeks of lactation. The correlation of these metabolites with estimated energy balance, and the effects of these ration variables on this correlation were studied. High concentrate diets (60% of dry matter) compared with low concentrate diets (40% of dry matter) increased mean plasma glucose values and reduced mean blood beta-hydroxybutyrate concentration. Variation in crude protein and methionine hydroxyanalog supplementation did not affect metabolite concentration. The correlations between blood beta-hydroxybutyrate and energy balance and between plasma glucose and energy balance were weak and subject to the influence of variation in ration composition. It was concluded that plasma glucose and blood beta-hydroxybutyrate concentrations cannot be used as valid indicators of energy balance. However, it did appear that blood beta-hydroxybutyrate might be used as an indicator of the relative glucogenic potential of dairy rations and that blood concentrations of this metabolite could potentially be used to adjust factors in the ration which influence glucose availability to the cow.

3-Hydroxybutyric Acid↗
PubMed1980

Colonic perforation following neurosurgical procedures and corticosteroid therapy in four dogs.

Perforation of the proximal descending colon occurred in four Dachshund dogs, each of which died 5 to 10 days following neurosurgical procedures. The complication was believed to be associated with parenteral use of dexamethasone. Correct antemortem diagnosis was made in only one of the four cases, probably because signs of a perforated viscus were so modified by the antiphlogistic effects of corticosteroids as to prevent early detection of the complication.

Animals↗
PubMed1980

Adaptation to hyperoxia in the neonatal rat: kinetic parameters of the oxygen-mediated induction of lung superoxide dismutases, catalase and glutathione peroxidase.

The activities of the enzymes superoxide dismutase, catalase and glutathione peroxidase increase in the lungs of neonatal rats exposed to normobaric hyperoxia. The oxygen-mediated increase in activity of these enzymes, known from previous studies to be an inductive response, was studied in 10- and 25-day-old rats as a function of both oxygen concentration and length of time of exposure to greater than 95% oxygen. In the lungs of 10-day-old rats the increase in superoxide dismutase, catalase, and glutathione peroxidase occurs only at 80% ambient oxygen or greater. In 25-day-old rats a similar pattern of response occurs with pulmonary catalase and glutathione peroxidase. However, unlike the response in 10-day-old rats, pulmonary superoxide dismutase does not increase in oxygen-exposed 25-day-old rats. The time course of enzyme induction was different for 10-day-old rats compared with 25-day-old rats. Exposure of 10-day-old rats to 95+% oxygen resulted in a significant increase in activity of superoxide dismutase after only 4 h when compared with air-exposed control animals. Catalasee and glutathione peroxidase in the same age group increased significantly after 6 h and 12 h of exposure to oxygen, respectively. Maximal levels of superoxide dismutase, catalase and glutathione peroxidase were reached after 6, 12 and 24 h of exposure to hyperoxia, respectively. This level of activity was then maintained throughout the subsequent exposure time up to 96 h. The activity of pulmonary catalase and glutathione peroxidase in 25-day-old rats did not increase significantly after 6 h of exposure to hyperoxia. An apparent plateau of increased activity was reached after 24 h of exposure. As observed with the 3 enzymes in 10-day-old rats, maximal enzyme activities were maintained throughout the subsequent period of oxygen exposure up to 96 h.

Adaptation, Physiological↗
PubMed1980

Proposed mechanism for neonatal rat tolerance to normobaric hyperoxia.

Induction of two forms of superoxide dismutase, catalase and glutathione peroxidase, occurs very rapidly in neonatal rat lung tissue upon exposure of these animals to 94 + % normobaric oxygen. No such oxygen-mediated enzyme induction occurs in the lungs of adult rats. The aged-dependent pattern of enzyme induction correlates with the well-established age-dependent tolerance of neonatal rats to hyperoxia. Enzyme induction occurs in the lungs of neonates in only those species known to be resistant to oxygen-provoked lung damage. Compromise of oxygen-mediated enzyme induction predisposed the neonatal rats to pulmonary oxygen toxicity. These data have formed the basis of the proposal that oxygen induction of the superoxide dismutases catalase and glutathione peroxidase provides a vital part of the defense mechanism against oxygen toxicity. A biochemical mechanism of oxygen-provoked pulmonary damage has been elaborated to explain the role of each enzyme in the protection against oxygen and free radical toxicity.

Age Factors↗
PubMed1980

Adverse effects caused by polypropylene and polyvinyl feline urinary catheters.

Effects of 3 days of open dwelling urethral catheterization were evaluated in normal male cats. Commercially manufactured polypropylene and polyvinyl feline urinary catheters of sufficient length to permit constant urine drainage were compared. Catheters were similar in length, diameter, and design. Hematuria occurred in 6 of 6 cats with polypropylene catheters and in 4 of 6 cats with polyvinyl catheters. For cats with polypropylene catheters, hematuria began within 24 hours of catheter insertion. Hematuria induced by polypropylene catheters was usually more severe in final urinalyses than that induced by polyvinyl catheters. Catheter-induced bacteriuria was found in 5 of 6 cats with polypropylene catheters and in 3 of 6 cats with polyvinyl catheters. Staphylococci and streptococci were the most common bacterial isolates. Microscopic lesions in urethras and bladders were significantly less severe in cats with polyvinyl catheters than cats with polypropylene catheters. With few exceptions, urethras of cats with polyvinyl catheters were microscopically indistinguishable from urethras of noncatheterized cats. Polypropylene catheters consistently induced urethritis which was most severe in some bacteriuric cats. Severe lesions were found in the bladders of all cats with polypropylene catheters. Bladder lesions were common in cats with polyvinyl catheters, but were usually less severe in cats with polypropylene catheters. There was no apparent relation between bacteriuria and bladder lesions.

Animals↗
PubMed1979

Effects of 1 alpha,25-dihydroxycholecalciferol on disuse osteoporosis in the dog: a histomorphometric study.

Disuse osteoporosis was produced in dogs by immobilization of the left rear limb in a plaster cast. The trabecular bone volume of the calcaneus was then determined following treatment with 1 alpha,25-dihydroxycholecalciferol for 4 weeks with oral dosages of 60 to 240 ng/kg of body weight. The trabecular bone volume percentage of the immobilized calcaneus was in direct relation to the dosage of 1 alpha,25-dihydroxycholecalciferol.

Animals↗
PubMed1978

Analysis of cerebrospinal fluid specific gravity.

The specific gravity of 71 CSF samples from clinically normal dogs ranged from 1.004 to 1.006, with a mean of 1.005. A 3-year retrospective study of CSF samples obtained from 124 animals suspected of having neurologic disease revealed only 30 samples (24.2%) having a specific gravity greater than 1.006. Diagnostic or prognostic value from CSF specific gravity determination was not recognized.

Animals↗
PubMed1978

Bilateral torsion of uterine horns in a nongravid bitch.

Hematometra was diagnosed in a 13-year-old, nulliparous Toy Poodle by fine needle aspiration and radiographic studies, including pneumoperitoneography. Attempted uterine evacuation with simultaneous use of diethylstilbestrol and ergonovine was unsuccessful. Exploratory celiotomy revealed 1,080-degree torsion of the right uterine horn around the left horn, which was itself twisted 270 degrees. Ovariohysterectomy was performed without complications.

Animals↗
PubMed1977

Effects of blood contamination on cerebrospinal fluid analysis.

Data were obtained from 190 cerebrospinal fluid samples collected from both clinically normal and diseased dogs, cats, cows, and horses. Red blood cells, indicating blood contamination, were identified in 115 samples. White blood cells were a rare finding in normal animals. Blood contamination appeared to have little effect on white blood cell numbers even though, in several samples, thousands of red blood cells were identified. An accepted formula to correct for blood contamination was found to be an unreliable method to determine "uncontaminated" values for white blood cells, total protein, or creatine phosphokinase.

Animals↗