Adenohypophyseal function in bitches treated with medroxyprogesterone acetate

The aim of this study was to investigate the effects of treatment with medroxyprogesterone acetate (MPA) on canine adenohypophyseal function. Five Beagle bitches were treated with MPA (10mg/kg, every 4 weeks) and their adenohypophyseal function was assessed in a combined adenohypophyseal function test. Four hypophysiotropic hormones (CRH, GHRH, GnRH, and TRH) were administered before and 2, 5, 8, and 11 months after the start of MPA treatment, and blood samples for determination of the plasma concentrations of ACTH, cortisol, GH, IGF-1, LH, FSH, prolactin, alpha-MSH, and TSH were collected at -15, 0, 5, 10, 20, 30, and 45 min after suprapituitary stimulation. MPA successfully prevented the occurrence of estrus, ovulation, and a subsequent luteal phase. MPA treatment did not affect basal and GnRH-induced plasma LH concentrations. The basal plasma FSH concentration was significantly higher at 2 months after the start of MPA treatment than before or at 5, 8, and 11 months after the start of treatment. The maximal FSH increment and the AUC for FSH after suprapituitary stimulation were significantly higher before treatment than at 5, 8, and 11 months of MPA treatment. Differences in mean basal plasma GH concentrations before and during treatment were not significant, but MPA treatment resulted in significantly elevated basal plasma IGF-1 concentrations at 8 and 11 months. MPA treatment did not affect basal and stimulated plasma ACTH concentrations, with the exception of a decreased AUC for ACTH at 11 months. In contrast, the maximal cortisol increment and the AUC for cortisol after suprapituitary stimulation were significantly lower during MPA treatment than prior to treatment. MPA treatment did not affect basal plasma concentrations of prolactin, TSH, and alpha-MSH, with the exception of slightly increased basal plasma TSH concentrations at 8 months of treatment. MPA treatment did not affect TRH-induced plasma concentrations of prolactin and TSH. In conclusion, the effects of chronic MPA treatment on adenohypophyseal function included increased FSH secretion, unaffected LH secretion, activation of the mammary GH-induced IGF-I secretion, slightly activated TSH secretion, suppression of the hypothalamic-pituitary-adrenocortical axis, and unaffected secretion of prolactin and alpha-MSH.     

Comparison of three closure methods and two absorbable suture materials for closure of jejunal enterotomy incisions in healthy dogs

The macroscopic and histological appearance of jejunal antimesenteric incisions approximated with two different absorbable suture materials (monofilament versus multifilament) and three closure techniques (appositional single layer, crushing single layer, and double layer) were compared in healthy dogs at 14 or 28 days, postoperatively. No significant differences between the two suture materials were observed for most of the macroscopic or histological variables. However, the monofilament suture material caused significantly more fibrous tissue reaction in the muscular layer of the jejunum than did the multifilament suture material. Of the three enterotomy closure techniques used in this study, the appositional single-layer method proved to be the best. The double-layer closure method caused a significant decrease in the incisional circumference, the relative circumference, and volume of the jejunum, and a significant increase in jejunal wall thickness. Our findings suggest that canine jejunal enterotomy incisions can be closed using an appositional suture pattern with relatively rapidly absorbable monofilament suture material. The use of double-layer suture patterns for closure of jejunal enterotomy incisions should be avoided because the size of the intestinal lumen may be reduced.     

Clinical neosporosis in the dog: a review

Neospora caninum is an intracellular protozoan parasite that was first recognized in dogs in 1988. N. caninum may cause neuromuscular disease in dogs. Later, it was discovered that N. caninum has a wide host range and is an important cause of abortion in cattle. In this article, the literature on N. caninum in the dog is reviewed, with emphasis on clinical signs, pathology, diagnosis, treatment, and prognosis.     

Identification of feline monocytes and neutrophils as effector cells in antibody-dependent cellular cytotoxicity: sequential analysis, using light microscopy, histochemistry, and scanning electron microscopy

Feline monocytes and neutrophils functioned as effector cells in antibody-dependent cellular cytotoxicity (ADCC) against antibody-coated chicken erythrocytes. Using light microscopy, effector cell populations were identified in effector-target cell interactions, with further characterization of these identical individual effector cells by histochemical evaluations and scanning electron microscopy. Monocytes and neutrophils, but not lymphocytes, were observed attacking target cells. Carbonyl iron depletion of monocytes and neutrophils from peripheral blood leukocytes caused a marked reduction from a mean of 62% to 3.6% lysis in ADCC as measured by a 4-hour 51Cr release assay. Effector cells functioning in the ADCC reaction were visualized, using sequential analysis and light microscopy, histochemistry, and scanning electron microscopy.     

Immunohistochemical Expression of Potential Therapeutic Targets in Canine Thyroid Carcinoma

Background

Thyroid carcinoma is a common endocrine tumor in the dog. Local invasive growth frequently precludes surgical excision and, in up to 38% of dogs, the tumor has already metastasized by the time of diagnosis. Therefore, it is important to investigate new treatment modalities that may be useful for the large number of dogs with inoperable tumors or metastatic disease.

Hypothesis/Objectives

To investigate the immunohistochemical expression of potential therapeutic targets in canine thyroid tumors.

Animals

74 dogs with thyroid neoplasia.

Methods

Immunohistochemistry was performed for thyroglobulin, calcitonin, vascular endothelial growth factor (VEGF), p53, cycloxygenase‐2 (cox‐2), and P‐glycoprotein (P‐gp).

Results

Fifty‐four (73%) tumors were classified as follicular cell thyroid carcinomas (FTCs) and 20 (27%) as medullary thyroid carcinomas (MTCs). Eighty percent of FTCs and all MTCs had a high percentage (76–100%) of neoplastic cells immunopositive for VEGF. Thirteen percent of FTCs and 50% of MTCs expressed cox‐2. Seven percent of FTCs and 70% of MTCs expressed P‐gp. No tumor was immunopositive for p53 expression. Expression of VEGF (P = .034), cox‐2 (P = .013), and P‐gp (P < .001) was significantly higher in MTCs compared to FTCs.

Conclusions and Clinical Importance

VEGF is a potential therapeutic target in both FTC and MTC in dogs. Cox‐2 and P‐gp may be useful molecular targets in canine MTC.     

Polyuria and Polydipsia and Disturbed Vasopressin Release in 2 Dogs With Secondary Polycythemia

In dogs, secondary polycythemia (SP) may be associated with polyuria and polydipsia (PU/PD). The pathogenesis of this PU/PD has not yet been explained. We hypothesized that hyperviscosity and increased blood volume in SP might affect vasopressin (VP) release, resulting in PU/PD. This hypothesis was tested in 2 dogs with SP caused by renal neo-plasia and PU/PD. Osmoregulation of VP release was studied by a modified water deprivation test and by investigating the VP response to hypertonic saline infusion.
Water deprivation test results were consistent with an inability to produce concentrated urine despite increasing plasma osmolality. During hypertonic saline infusion, the osmotic threshold of VP release was markedly increased in both dogs, resulting in a delayed VP response to increasing plasma osmolality. The sensitivity of VP release was low normal in both dogs. We conclude that blood hyperviscosity and increased blood volume led to impaired VP release and polyuria.     

Integrated research in archaeology using soil micromorphology and palynology

Archaeologists often encounter problems in interpreting the genesis of layers and the context in which specific materials occur in excavations. Field visits of geologists, soil scientists or biologists can solve a number of questions, but often, problems remain that only can be studied by microscopic research as, for example, soil micromorphology and palynology. In the past, the employment of these two disciplines, one in earth science and one in biology, generally occurred independently of each other, also in interdisciplinary research and contract research. Consequently, results could not always be correlated, permitting only a restricted integration of data. It was realised that soils, as archives, contain much more information than generally utilised. A skillful employment and balancing of both specialties create a real integrated approach that offers a substantially improved interpretation potential without hardly additional efforts and costs. The results of 7 years of experience were very stimulating and presented here.In this article, the essence of soil micromorphology and palynology applied to archaeology is briefly outlined and illustrated by selected examples of the different research themes covered, showing the possibilities and results of integrated research. Both specialties generate essential information that, when combined and integrated properly, lead to improved understanding of the landscape genesis and human activities in the past. To be able to employ the full interpretive potential of this integrated approach, the research procedures followed by both specialties had to be compared. The key requirements for optimal integration of each other's databases comprised a combined effort to compare the pros and cons during the first four steps of the research procedure: defining research questions, field survey, selection of sampling locations and sampling. This approach enabled optimal correlation of the individual results, made cross-checking and references possible and led to higher levels of interpretation that would not have been possible otherwise. The integrated research elucidated lacunae in the other's discipline, resulting in a distinctly more complete reconstruction of paleoenvironments and past land uses, important research themes of archaeologists for the specialties concerned.