A local increase in the mammary IGF-1: IGFBP-3 ratio mediates the mammogenic effects of estrogen and growth hormone

A single epithelium-free mammary fat pad was surgically prepared in each of twenty-five one-month-old, Friesian heifers. At 18 mo of age, heifers were randomly assigned to one of four treatment groups. Treatments were: control (C), growth hormone (GH), estrogen (E) or growth hormone + estrogen (GE). Hormones were administered for 40 hr before the animals were sacrificed to provide mammary samples of parenchyma (PAR), intact fat pad (MFP), and epithelium-free or "cleared" fat pad (CFP). IGF-1 and IGF binding protein-3 (IGFBP-3) mRNA was highest in CFP and MFP whereas the protein products were highest in PAR. IGFBP-2, a 28-kDa IGFBP and a 24-kDa IGFBP were more abundant in CFP and MFP. E and GH increased incorporation of [(3)H]thymidine into DNA of PAR. Incorporation of [(3)H]thymidine into the DNA of MFP or CFP was minimal. Coincident with the changes observed in mammary epithelial proliferation, E increased IGF-1 protein in MFP and PAR, and to a lesser extent in CFP. E tended to increase IGF-1 mRNA levels in MFP, but not CFP implying that the regulation of IGF-1 expression is modulated by adjacent epithelium. GH and E reduced IGFBP-3 protein in PAR and increased the 24-kDa IGFBP in CFP and MFP. Increased proliferation of mammary parenchymal cells was associated with increased IGF-1 and reduced IGFBP-3 protein in mammary tissue. An increase in the ratio of mammary IGF-1: IGFBP-3 likely increases the proportion of the mammary IGF-1 available to stimulate proliferation. These data also indicate that stromal: epithelial interactions regulate the IGF-1 axis in mammary tissue.     

Sebaceous adenitis in the Akita: clinical observations, histopathology and heredity

Ninety-seven pure-bred Akitas were examined clinically and histologically for sebaceous adenitis. The diagnosis was established histologically in 23 Akitas by demonstrating an inflammatory reaction targeted against the sebaceous glands or a reduction in the number of glands. The clinical course of sebaceous adenitis in the Akita was similar to that seen in other breeds. The first skin lesions occurred mainly on the dorsal midline and ears. Compared with the Poodle, the age at first onset of the disease was more variable and the hair loss affected mainly the undercoat. The progression of sebaceous gland destruction varied between dogs and was not seen in all cases. Because bud-like sebaceous gland proliferation could be identified, it seems that regeneration of the sebaceous glands may occur. An autosomal recessive inheritance appears to be possible. Apart from a genetic background, immune-mediated factors possibly influence the onset and course of sebaceous adenitis.     

Response of Corriedale and Crioula Lanada Sheep to Artificial Primary Infection with Haemonchus Contortus

Clinical, parasitological and biochemical parameters were evaluated in Corriedale and Crioula Lanada sheep after a single experimental infection with Haemonchus contortus. Ten 4-month-old worm-free lambs, of each breed, were infected with 200 L₃ H. contortus per kg live weight and four uninfected animals of each breed were used as controls. Every week, the animals were weighed and blood and faecal samples were collected for measurement of packed cell volume (PCV), total serum protein (TSP) and albumin (ALB), and the number of eggs per gram of faeces (EPG), respectively. Twelve weeks after infection, the animals were slaughtered. The worm burden was determined and samples of the abomasal mucosa were processed for determination of the number of eosinophils, mast cells and globule leukocytes. No significant differences in PCV, TSP, ALB, parasite burden or the cell populations of the abomasal mucosa were observed between breeds, but Crioula lambs had a lower EPG count. The comparison of the infected groups with their respective controls revealed significant alterations in PCV, TSP and ALB in the Corriedale lambs and in PCV, TSP, ALB and the density of eosinophils and mast cells in the Crioula lambs.     

Hyaluronidase administered with xylazine–tiletamine–zolazepam into adipose tissue shortens recovery from anesthesia in pigs

Objective

To evaluate the effect of hyaluronidase on uptake, duration and speed of elimination of xylazine–tiletamine–zolazepam administered in the subcutaneous fat over the dorsal lumbar region of swine.

Anaesthesia of a Sumatran tiger on eight occasions with ketamine, medetomidine and isoflurane

CASE: An 18-month-old male Sumatran tiger was referred for endoscopy and dilatation of an oesophageal stricture. Anaesthesia and bouginage was undertaken on eight occasions 2-3 weeks apart to dilate the oesophageal stricture. CLINICAL FINDINGS: On the first occasion, sedation was induced with a combination of medetomidine (30 microg/kg) and ketamine (2.35 mg/kg) given intramuscularly. Cardiopulmonary depression (characterised by bradycardia, ventricular arrhythmias, hypoventilation and cyanosis) was severe and in subsequent anaesthesias the medetomidine dose was decreased to about 18 microg/kg and the ketamine dose increased to about 3 microg/kg given intramuscularly. Immobilisation was adequate and the severity of the cardiopulmonary depression was reduced at the revised drug dosages. Atipamezole was effective in reversing both the cardiopulmonary and central nervous system depression. CONCLUSION: The dosage of medetomidine and ketamine recommended in the literature for immobilising tigers produced severe cardiopulmonary depression in this animal. A reduced dosage of medetomidine and higher dosage of ketamine provided adequate restraint with decreased cardiopulmonary depression.     

Characteristics of the response of ovine granulocytes (PMNs) to zymosan-activated serum (ZAS) and to recombinant human interleukin-8 (IL-8)

The chemotactic activity of zymosan-activated serum (ZAS) and of two concentrations of recombinant human IL-8 (IL-8(25), 25 ng/ml; IL-8(50), 50 ng/ml) for ovine polymorphonuclear granulocytes (PMNs) was tested in a modified Boyden chamber. Thick cellulose acetate filters and the leading front method were used to quantify the movements of the cells. Both ZAS and IL-8(25) exerted a chemotactic effect on ovine PMNs (P < 0.01): IL-8(50) induced a more homogeneous response (P < 0.001). To verify the characteristics of the responsiveness to the chemokines after short-term (st) or long-term (lt) repeated samplings, chemotaxis was investigated 1 (T1st), 2 (T2st), 24 (T3st) and 48 h (T4st) after the basal sampling (T0st) and 15 days (T1lt) after the basal sampling (T0lt). No differences in chemotaxis were found in long-term repeated samplings. In contrast an increase in the responsiveness to IL-8(25) and to IL-8(50) (P < 0.05) was detected at T2st in comparison with T0st. Furthermore, the significance of the distance run by activated PMNs compared with the controls, increased from T0st to T2st, as a sign of a more homogeneous response to the chemokines. In the absence of evident changes in circulating leucocyte numbers and in serum cortisol concentrations, these findings could be interpreted as a consequence of a different expression of chemoattractant receptors on the membrane of PMNs collected at different times.     

Evaluation of parameters for the differentiation of acute from chronic renal failure in the dog

The differentiation of acute (ARF) from chronic (CRF) renal failure is important for therapeutic and prognostic reasons and should be established as soon as possible. In practice this differentiation is often based on history, physical examination and laboratory results. In this retrospective study the diagnostic accuracy of parameters to differentiate ARF from CRF was tested in 19 dogs with ARF and 49 dogs with CRF. The diagnostic accuracy of body condition was 65%, of the hematocrit 78%, of serum potassium levels 28%, of total CO2 48%, of urinary casts 77%, of glucosuria 90% and of the urine protein-to-urine creatinine ratio 43%. Of all the parameters evaluated only glucosuria revealed an acceptable discriminating quality with a sensitivity of 92% and a specificity of 89%. A limitation of this factor is, that glucosuria depends on the cause of ARF. The single parameters tested are not very useful and the diagnosis of ARF or CRF is based on a combination of parameters from history, physical examination, laboratory results and diagnostic imaging. If a diagnosis can't be established immediately, treatment for ARF is recommended. With an immediate, aggressive treatment the possibility of total recovery from ARF is increased.     

Morphological aspects of in vivo cleavage in Myocastor coypus (coypu)

The objective of the present work was to characterize the in vivo cleavage stage of Myocastor coypus embryos. For this purpose a colpocytological follow-up and controlled mating of 18 females were performed. Specimens from the beginning of the first cleavage to the acquisition of a morula appearance were considered to be in cleavage stage. Embryos in cleavage were collected between days 3 and 6 post-coitus. Of the collected embryos, 80% presented an even number of blastomeres and the remaining 20% an odd number. Embryos from 3 to 7 cells were blastomere associations in a spherical disposition within the zona pellucida. Blastomeres were spherical or ovoid, presenting slight flattening in areas contacting with other blastomeres. Embryos of 8 and 9 cells were as a group of blastomeres slightly elongated, surrounded by a spherical zona pellucida. The percentage of peri-vitelline space occupied by the embryonic mass ranged from 74.1 to 95.8% for all the substages. The cleavage pattern, developed in the oviduct, was of a rotational holoblastic type and asynchronic.