Antigenicity of cortical bone allografts in dogs and effect of ethylene oxide-sterilization.

The aims of the present study were to determine the antigenicity of cortical bone allografts and the effect of ethylene oxide-sterilization (EO-sterilization). Cortical bone allografts from one donor dog were implanted in a muscle pouch in four groups of four dogs each. The grafts were either fresh, EO-sterilized, demineralized or demineralized and EO-sterilized. The immune response against the grafts was determined by measuring the antibody response against surface antigens of donor cells and by the mixed lymphocyte reaction. Dogs receiving EO-sterilized grafts or bone matrix did not demonstrate an immune response. Only two of the four dogs with fresh cortical bone grafts showed a very weak immune response. This suggests a priming of the host by the fresh bone grafts. However, implanting skin grafts from the donor dog subdermally, in one dog of each of the groups, four months after implanting the bone grafts did not induce a secondary immune response. Macroscopic and histologic examination of the bone grafts five months after their implantation consistently revealed graft resorption (activity of osteoclasts) and vascularization of the fresh bone grafts, but not of EO-sterilized fresh grafts. For most EO-sterilized grafts, a strong inflammatory reaction was present in the tissues surrounding the graft and this was not apparent around the non-sterilized grafts. The absence of resorption and the presence of the inflammation seemed to be unwanted effects of the EO-sterilization. The EO-sterilisation did not affect osteoinduction since osteocytes were observed in the EO-sterilized demineralized grafts. Results indicate that cortical bone allografts used in the present study are very weak antigens and that the EO-sterilization procedure used has no effect on osteoinduction, but decreases bone resorption.

Sufentanil and nitrous oxide anaesthesia for the recording of transcranial magnetic motor evoked potentials in dogs.

Transcranial magnetic motor evoked potentials were recorded from the extensor carpi radialis muscle of the forelimbs and from the cranial tibial muscle of the hindlimbs of anaesthetised dogs. The dogs were premedicated with droperidol and fentanyl and a light plane of anaesthesia was induced and maintained with sufentanil and nitrous oxide. The potentials recorded under sufentanil and nitrous oxide anaesthesia were suppressed in comparison with baseline recordings under droperidol and fentanyl sedation: their latencies were significantly increased and their amplitudes significantly decreased (P < 0.05). However, the potentials could be recorded reliably in all the dogs and with very good reproducibility. This narcotic anaesthesia also allowed sensory evoked potentials to be recorded reliably.

Comparison of two techniques of narcotic-induced anesthesia for use during recording of magnetic motor evoked potentials in dogs.

OBJECTIVE: To compare 2 types of narcotic-induced anesthesia for recording of transcranial magnetic motor evoked potentials (TMMEP) in dogs. DESIGN: The effect of different doses of sufentanil and midazolam and of sufentanil and nitrous oxide on onset latencies and peak-to-peak, amplitudes of TMMEP was evaluated and compared. ANIMALS: 18 neurologically normal dogs. PROCEDURE: Premedication with droperidol and fentanyl. Induction and maintenance of anesthesia either with sufentanil and midazolam or with sufentanil and nitrous oxide. Recording of TMMEP from the extensor carpi radialis muscle of the forelimb and from the cranial tibial muscle of the hind limb. RESULTS: Both types of narcotic anesthesia induced dose-dependent suppression of TMMEP; compared with baseline recordings, latencies increased, amplitudes decreased, and reproducibility became poorer with increasing dose of the anesthetics. Using surgical-depth doses of the anesthetics, TMMEP could still be recorded in all dogs with sufentanil and nitrous oxide, but not with sufentanil and midazolam anesthesia. CONCLUSIONS: Sufentanil and nitrous oxide anesthesia was superior to sufentanil and midazolam anesthesia for TMMEP recording. CLINICAL RELEVANCE: In small animal medicine, and in dogs in particular, spinal cord diseases are among the most frequently encountered neurologic disorders. The development of techniques for recording TMMEP in anesthetized dogs allows noninvasive evaluation of transmission along descending motor pathways of the spinal cord.

A tremor syndrome with a central axonopathy in Scottish terriers.

A central axonopathy in 2 male and 1 female Scottish Terrier puppies from 3 different but related litters is reported. Clinical signs consisting of severe whole-body tremors and ataxia were first detected at the age of 10 to 12 weeks. They worsened with activity and excitement and diminished during rest or sleep. Two dogs also had paraparesis. In 1 dog the neurological deficits progressed over several months. Neuropathological examination revealed widespread axonal changes, vacuolation, and gliosis in the white matter of the central nervous system.

Liquid chromatographic determination of ampicillin in bovine and dog plasma by using a tandem solid-phase extraction method.

The determination of ampicillin in plasma and serum by reversed-phase high-performance liquid chromatography with UV detection suffers from poor selectivity and sensitivity. Currently, the most common approach to overcoming these problems consists of improving the compound's detectability via pre- or postcolumn derivatization. In the method that we describe, however, enhanced selectivity is afforded by sample purification by a tandem solid-phase extraction method (ion-exchange and reversed-phase). This approach permits detection at wavelengths of as low as 210 nm, which results in enhanced sensitivity (detection limit, 0.01 microgram/ml). A second factor that affects selectivity is the addition to the chromatographic eluent of a crown ether to optimize the separation between ampicillin and polar endogenous plasma constituents. This combination of improved sample pretreatment and a more selective chromatographic system in conjunction with internal standardization forms the basis of a new assay for the quantitation of ampicillin in plasma. The overall recovery of ampicillin was 76.4% +/- 4.9% (n = 24), and the within-run and between-run coefficients of variation ranged from 1.6 to 7.2%. The method was applied to pharmacokinetic studies in cows and dogs after intramuscular or oral administration of the drug.

Concentrations of oestradiol and testosterone in peripheral and spermatic venous blood of dogs with unilateral cryptorchidism.

Plasma testosterone and oestradiol concentrations were measured in peripheral and spermatic venous blood of 13 dogs with unilateral inguinal cryptorchidism, 9 dogs with unilateral abdominal cryptorchidism, and in a control group of 36 mature normal dogs. The hormone concentrations were similar in the three groups, both in the peripheral and in the spermatic venous blood. The weight of the testes in the control group was correlated with the body weight and there was no significant difference between the weight of the right and the left testes. The weight of the abdominal testes was lower than that of the inguinal testes, and there was no compensatory enlargement of the contralateral scrotal testis. The cryptorchid testes showed little or no histological evidence of spermatogenesis, and spermatogenesis was usually normal in the scrotal testes.

Diabetes mellitus in dogs: relationship of obesity to glucose tolerance and insulin response.

The IV glucose-tolerance test was performed in 71 diabetic dogs (fasting glycemia greater than 6.70 mmol/L) and in 20 healthy dogs. All diabetic dogs were characterized by various degrees of glucose intolerance as expressed by an abnormal glucose disappearance coefficient. On the basis of the fasting plasma insulin concentration (Io), insulin peak response (IPR), the insulinogenic index (delta I/delta G), and the total insulin secretion (TIS), the diabetic dogs were classified, as follows: Type I dogs (n = 32) which had the severe clinical signs of diabetes and an absence of certain diagnostic responses: Io, IPR, delta I/delta G, and TIS. Type II dogs (n = 15) which also had marked diabetic signs and an absence of IPR, delta I/delta G, and TIS responses. The dogs were further subdivided into obese and nonobese groups; the Io was within acceptable limits in the nonobese group (n = 8), but was markedly increased in the obese group (n = 7). Type III dogs (n = 24) had no diabetic signs and a fasting plasma glucose less than 12 mmol/L. They were also subdivided into obese and nonobese groups. The nonobese dogs (n = 13) had Io values within acceptable limits and decreased IPR, delta I/delta G, and TIS. In contrast, the obese dogs had increased Io, IPR, delta I/delta G, and TIS. Statistical analyses indicated that the TIS and IO were highly significant linear functions of obesity.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucose uptake and insulin secretory responses to intravenous glucose loads in the dog.

Twenty-one healthy young non-anesthetized Dalmatian dogs (10 male, 11 female) were given IV glucose loads between 300 and 1,500 mg/kg of body weight in a standard time period of 30 s. The fractional glucose turnover rates and the insulin peak responses gradually increased with glucose loads to 1,000 mg/kg and the total insulin secretion with loads to 1,250 mg/kg and remained constant. The insulinogenic index (delta I/delta G) varied inversely with the size of the glucose loads. The pattern of responses indicates that the optimum glucose load is near 600 mg/kg for evaluating normal glucose metabolism in dogs by the IV glucose loading technique.

Internal fixation of a fractured humerus in a dog and late osteosarcoma development.

Five years after an intramedullary nailing of a fractured humerus a fistula developed in a dog. The nail was removed and a gross swelling developed 11 weeks later. Osteosarcoma was diagnosed.

Renal clearance, insulin secretion and glucose tolerance in spontaneous diabetes mellitus of dogs.

A standard intravenous glucose tolerance test (IVGTT) and the insulin response to the glucose loads were studied in 14 cases of diabetes mellitus in dogs. In addition, urinary glucose excretion, and clearances of urea, creatinine and phosphate were also determined in these dogs. All diabetic dogs were characterized by glucose intolerance as expressed by an abnormal half-time (T 1/2) or fractional clearance rate (k-value) and were further classified as Types I, II or III diabetes on the basis of their insulin responses. Renal functional impairment was observed in about 60 percent of the cases and was generally mild. There appeared to be no apparent relationship between advanced chronic renal disease and severity of diabetes in dogs.