POLYARTHROPATHY AND ANTERIOR UVEITIS AS PARANEOPLASTIC SYNDROMES IN A GUINEA PIG WITH DISSEMINATED LYMPHOMA

A 4-year-old, intact male guinea pig was presented for evaluation of ocular pain and forelimb lameness. Initial examination confirmed that the ocular pain was associated with bilateral anterior uveitis and that the lameness was attributed to a bilateral carpal and metacarpal polyarthropathy. Carpal joint taps revealed nonseptic marked mixed inflammation later confirmed as a nonerosive immune-mediated polyarthropathy. Treatment with topical steroid ophthalmic ointment resulted in rapid resolution of the uveitis; the arthropathy was initially managed with pain medication and anti-inflammatories, then later with doxycycline and cyclosporine. Over the course of 7 days, the joint swelling and pain improved slightly, but the patient developed severe exophthalmos of the right eye. An ocular ultrasound examination revealed a space occupying mass in the retrobulbar space and results of a fine needle aspirate of the mass was diagnosed as lymphoma. Treatment with prednisone was set to be initiated after a 3-day wash-out period of meloxicam, but the patient was euthanized before the initiation of chemotherapy. Necropsy results confirmed the lymphoma had infiltrated the right eye, kidneys, adrenal glands, thyroid glands, lungs, liver, spleen, testicular interstitium, urinary bladder, pancreas, mesentery, lymph nodes, and meninges. This is an unusual presentation of apparent paraneoplastic uveitis and immune-mediated polyarthropathy in a guinea pig.     

DIAGNOSIS AND SURGICAL TREATMENT OF A TRANSITIONAL CELL CARCINOMA IN THE BLADDER APEX OF A PET RABBIT (ORYCTOLAGUS CUNICULUS)

A 6-year-old, 1.9-kg female spayed lop-eared European rabbit (Oryctolagus cuniculus) was evaluated for acute hematuria and inappropriate urination and defecation of less than 12-hours duration. Abdominal ultrasonography revealed a suspected bladder mass. Ultrasound-guided cystocentesis was performed and the results of the urinalysis were unremarkable. An abdominal exploratory surgery revealed a nodular cystic mass at the cranial ventral apex of the bladder wall which measured 0.5 cm × 0.5 cm. Based on histopathologic evaluation, excision of the neoplasm was complete and the mass was diagnosed as transitional cell carcinoma of the bladder. This case suggests that urinary bladder transitional cell carcinoma should be considered in pet rabbits presenting with similar clinical signs.     

Progesterone production in granulosa cells of the domestic fowl: effects of incubation media, pH, cell density and some other factors

The objective of this study was to determine the optimal conditions for the short term incubation of chicken granulosa cells. Compared to mechanically-dispersed cells, collagenase-treatment yielded granulosa cells of greater viability and responsiveness to ovine LH (oLH) stimulation. The rate of progesterone secretion by enzyme-dispersed chicken granulosa cells was subsequently compared in five different culture media during incubation periods of up to 24 hr. Under room air as the gas phase, Medium 199 (M199) containing Hank's salts and Ham's F-12 medium (F-12) were the most effective, whereas Krebs-Ringer bicarbonate-buffered glucose solution (KRBG) and Dulbecco's medium were the poorest. When pH and the ionic strength of KRBG was maintained by continuous gassing with O₂:CO₂ (95:5), progesterone production was similar to that obtained with Hepes-buffered M199. The pH optimum was found to be 7.4, although within the range of 6.6–8.5 granulosa cells remained responsive to LH stimulation. The optimal cell density was observed to be 1 × 10⁴ to 5 × 10⁵/ml. Although time course studies showed that both basal and stimulated progesterone production peaked by about 12 hr of incubation regardless of the media composition, the amounts released were significantly greater in M199 and F-12 during more prolonged (up to 24 hr) incubations. Glucose, a key medium ingredient for hormone-stimulated steroidogenesis, could be replace by pyruvate. On the other hand, lactate was inhibitory. It is concluded that the mature ovarian follicles of the domestic fowl are an excellent source of pure granulosa cells that can be obtained in high yield after a brief treatment with collagenase. These cells remain viable up to 24 hr and continue to produce large amounts of progesterone in response to LH when incubated in an appropriate medium and at optimal cell density.     

Seasonal and lactational effects on response to thyrotropin releasing hormone injection in Holstein cows

Fifty-four lactating Holstein cows were used to define relationships between stage of lactation and environmental measures on thyrotropin releasing hormone (TRH)-induced secretion of triiodothyronine (T₃, thyroxine (T₄) and prolactin. Mean black globe temperatures were -.3, 20.6, and 25.5C for winter, spring, and summer months, respectively. The circulating hormone responses of T₃, T₄ and prolactin were significantly affected by season, sampling time and there was a season by sampling time interaction. T₄ response was affected by stage of lactation, while prolactin responses differed by stage of lactation across the three seasons. Both T₃ and T₄ responses were lowest in winter and may indicate greater utilization rates to meet metabolic demands. T₃ responses peaked near 3 hr post TRH, while T₄ increased to the end of the 7 hr sampling period. Prolactin responses to TRH increased from winter through summer and were responsive to changes in ambient temperature and photoperiod. T₄ response increased with advancing stage of lactation and could be due to changes in metabolic activity and clearance. Spring TRH-induced prolactin response decreased with advancing lactation whereas, the response increased as lactation progressed during the summer. Monthly milk yield was affected by stage of lactation and lactation number. Early lactation cows produced most milk and milk yield peaked in third lactation. Differential responses to TRH may reflect alterations in milk yield during different stages of lactation.     

Malunion of an in utero open tibial fracture in an aborted equine fetus

An in utero tibial fracture was examined at necropsy in a seven-month-old male aborted Thoroughbred fetus. Grossly the healed fracture had a smooth cortical surface. Histologically there was no callus formation or excessive osteoclastic or osteoblastic activity.     

Thyroid stimulating hormone and prolactin secretion after thyrotropin releasing hormone administration to mares: Dose response during anestrus in winter and during estrus in summer

The response of thyroid stimulating hormone (TSH) and prolactin (PRL) concentrations to administration of thyrotropin releasing hormone (TRH) was determined in light-horse mares during the anestrous season (winter) and during estrus (standing heat) in the summer. Within each season, mares (4/group) were treated with either saline (controls) or one of four doses of TRH (80, 400, 2,000 or 10,000 ug) intravenously. Samples of blood were drawn at −15, −.5, 15, 30, 45, 60, 90, 120, 180 and 240 min relative to TRH injection. Concentrations of TSH and PRL in pre-TRH samples were greater (P<.05) in anestrous mares during winter than in estrous mares during summer. Concentrations of TSH increased (P<.05) within 30 min after administration of TRH and remained elevated during the 4-hr sampling period. The maximal net change in TSH concentrations and the area under the response curve were greatest for 2,000 ug of TRH; 80 ug did not produce a significant TSH response. There was no interaction (P >.10) between reproductive state and TRH dose for TSH concentrations. Concentrations of PRL were not significantly affected by any TRH dose during either season. It appears that mares differ from many mammalian species in that they do not respond to an injection of TRH with increases in both TSH and PRL.     

Plasma clearance and tissue uptake of native and desialylated equine gonadotropins

Equine luteinizing hormone (eLH), equine follicle stimulating hormone (eFSH) and equne chorionic gonadotropin (eCG) were desialylated and their plasma disappearance, tissue uptake and degradation determined. Both native hormones and their desialylated derivatives were radioiodinated and injected intravenously into male rats. Plasma samples were taken at different time intervals and examined for both total and trichloroacetic acid (TCA) precipitable radioactivity. Disappearance curves for each hormone consisted of two exponential components: a fast clearance followed by a slow phase. The apparent $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of the fast component for native eCG, eLH and eFSH were 18.3 min, 17.0 min and 17.1 min, respectively; this is in contrast to their desialylated derivatives which had a $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of 2.8 min, 4.9 min and 7.1 min, respectively. The slower component for native and desialylated eCG had at $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of 355.5 min and 171.2 respectively. After TCA precipitation more than 90 percent of the radioactivity in plasma was in the pellet, whereas in urine almost 95 percent of the radioactivity was in the TCA supernatant. Coincident with the disappearance of the hormone from the plasma its uptake and release was observed in liver, kidney, testis, and muscle tissue. Gel filtration data on plasma and urine samples indicated that the former had mostly intact hormone in contrast with the latter. Together these results indicate that eLH, eFSH and eCG disappear from the plasma of male rats in a biphasic manner with a rate slower than their desialylated derivatives.     

Ovarian inhibition of pulsatile luteinizing hormone secretion in prepuberal holstein heifers

Fifteen prepuberal Holstein heifers were utilized to examine pulsatile luteinizing hormone (LH) secretion before and after ovariectomy. Heifers were ovariectornized at 3, 6 or 9 months of age (n=5/group) and scheduled for blood sampling at 1 week before, 1 week after and 4 weeks following ovariectomy. During each 8 hr sampling period (0600–1400 hr), blood samples (10 ml) were collected via indwelling jugular canulae at 10 min intervals. Prior to ovariectomy, mean plasma LH concentration and both number and amplitude of LH pulses per 8 hr sampling period were similar (P>.05) among age groups, and the absence of a pulsatile LH secretion profile was accompanied by a low mean LH concentration. Within 1 week after ovariectomy, both number of LH pulses and mean LH concentrations increased (P<.O1) in all age groups. Between 1 and 4 weeks after ovariectomy, both amplitude of LH pulses and mean LH concentrations increased (P<.O1) when the data from the three age groups were combined. We conclude that ovarian inhibition of pulsatile LH secretion is established by 3 months of age and is maintained through 9 months of age. In addition, the initial elevation mean plasma LH concentration is due to greater pulse frequency, while the subsequent rise in mean LH concentration reflects increased amplitude of LH pulses.     

Pasteurella haemolytica: purification of saline-extractable proteins by isoelectrofocusing

A procedure was developed for separating antigens associated with a saline extract of Pasteurella haemolytica serotype 1. Seven antigens were identified by immunoelectrophoresis to be associated with the extract. The extract was subjected to preparative isoelectrofocusing in a pH range of 3-10. The majority of extracted proteins were found to have pI's of 4-6, whereas the carbohydrate antigen(s) were distributed over a pI range of 3.0-8.0. The fractions that were of interest were pooled and refocused in a narrower pH range to improve resolution of the protein antigens. Specific antigens from defined pH ranges were pooled to form 6 antigen groups. These antigen groups were examined further by immunoelectrophoresis, analytical isoelectrofocusing, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The molecular weights of the proteins found in the capsular extracts ranged from 33 k to greater than 80 k. Injection of mice with capsular extract or antigen Groups 1-6 in Freund's incomplete adjuvant resulted in a serum antibody response to the various antigens as detected by an enzyme-linked immunosorbent assay. Significant protection (P less than 0.05) against challenge with virulent P. haemolytica was seen in mice injected with antigen Groups 2 and 4. Six calves were immunized with saline extract. These calves had greater resistance to experimental pneumonic pasteurellosis than did 6 non-vaccinated calves. A serum antibody response to the crude extract and to each antigen group was detected in vaccinated calves by an enzyme-linked immunosorbant assay.     

MOTOR AND SENSORY NERVE CONDUCTION STUDY IN THE FERRET

Ferrets are considered a popular small mammal pet, and like other companion animals they are reported to suffer from diseases affecting the neuromuscular system. There currently is a lack of comprehensive electrodiagnostic study regarding the appendicular nerves of ferrets. In this research investigation, 25 domestic ferrets were used for electromyography and motor nerve conduction studies of the tibial, fibular, ulnar, and radial nerves, including H reflexes of the tibial and ulnar nerves, as well as sensory conduction of the fibular nerve. Mean and standard deviations for motor and sensory nerve studies were established. The hypothesis that weight would be correlated with all distal and proximal compound muscle action potential latencies was tested and confirmed for the tibial, fibular, and radial nerves but not the ulnar nerve.     

Effect of suckling intensity on human growth hormone binding, biochemical composition and histological characteristics of ovine mammary glands

Suckling both, or only one contralateral mammary gland during 15 days postpartum was utilized to study lactogenic hormone binding to mammary microsomal membranes and quantitative mammary morphology in ewes. Binding of radiolabeled human growth hormone was specific for lactogenic hormones. Non-radiolabeled human growth hormone, ovine and bovine prolactin and human placental lactogen effectively competed with radiolabeled human growth hormone for binding sites but ovine and bovine growth hormone were completely ineffective. Specific binding of radiolabeled human growth hormone to 600 μg of membrane protein averaged 23 ± 3% in all lactating glands. Neither days postpartum nor treatment of contralateral mammary glands substantially altered hormone binding in lactating glands. Specific human growth hormone binding (6 ± 0.5%) in non-suckled glands (15 days postpartum both udder halves) was significantly lower (P<0.01) than in lactating tissue but only a moderate and variable reduction in specific binding was measured in membranes from glands non-suckled for 15 days but contralateral to a suckled gland (14 ± 4%). Specific binding was approximately doubled in assays with 600 compared with 300 μg of membrane protein and the pattern of binding among variously suckled glands was not changed by treatment of membranes with 4 M MgCl₂ prior to assay. Most secretory cells from all lactating glands had rounded, basally displaced nuclei, apical fat globules, secretory vesicles and abundant densely stained basal cytoplasm (ergastoplasm). Alveolar lumenal area was maximal (50% of tissue area) and stromal tissue area was minimal. After 15 days of non-suckling (both udder halves) mammary cells were engorged with lipid, ergastoplasm was reduced and nuclei were irregularly shaped and randomly displaced compared with lactating tissue. In addition, lumenal area was reduced and stromal tissue more evident. Lack of suckling for 5 days had little apparent effect on mammary cytology. Like lactogenic hormone binding, mammary tissue morphology was only moderately altered by 15 days of non-suckling when the remaining gland was suckled. RNA concentration was lowest (2.1 ± 0.3 mg/g) in mammary tissue from ewes in which neither gland was suckled for 15 days postpartum but non-suckling interval had no significant effect when contralateral glands were suckled. DNA concentration was not significantly influenced by suckling treatments. Relative lactogenic hormone binding closely corresponded to changes in cytological and biochemical indices of secretory cell function.     

Severe Leukemoid Response Associated With Mycobacterium genavense Infection in a Pet Budgerigar (Melopsittacus undulatus)

A 2-year-old pet budgerigar was presented after a period of general malaise that was unresponsive to supportive therapy. Radiographic images revealed a marked hepatomegaly. Hematology results indicated the bird had a severe leukocytosis with marked discrepancy between the hemocytometer white blood cell (WBC) count and WBC estimated from the smear. The leukocytosis was characterized by an extreme heterophilia with marked left shift, including the presence of metamyelocytes and promyelocytes with marked toxic changes, and a marked monocytosis, consistent with a leukemoid response. The bird died despite supportive treatment. Hepatosplenomegaly was present at necropsy. Histopathology of multiple tissues demonstrated acid-fast organisms on Ziehl-Neelsen staining, subsequently identified as Mycobacterium genavese by polymerase chain reaction analysis. Mycobacteriosis should be considered as a differential diagnosis in the presence of a severe leukemoid response with multiple heterophilic precursors in avian species.     

Central role of insulin in growth and development

Insulin has been shown to have an impact on both prenatal and postnatal growth. Specific mechanisms of insulin action on adipose cell function and lipid storage are well defined. Insulin probably acts in concert with other anabolic factors (i.e., growth hormone and somatomedins) to stimulate muscle protein anabolism and suppress protein catabolism (Figure 2). Insulin also plays a role in energy balance regulation by the hypothalamus, however exact mechanisms of effects on brain metabolism have not been clearly identified.