The use of semi-quantitative tests at Cesarean section delivery for the differentiation of canine fetal fluids from maternal urine on the basis of biochemical characteristics.

In dogs, there is no diagnostic test to identify and differentiate fetal fluids from maternal urine in the event that a clear-yellowish vulvar discharge is observed pre-whelping. The objective of this study was to find a test that could easily and accurately identify rupture of the fetal membranes preceding parturition. Maternal urine, and amniotic fluid (AMF) and allantoic fluid (ALF) from only one fetus per bitch, were collected intraoperatively during Cesarean section. Specific gravity (SG) was analyzed with a refractometer, whereas the presence of leukocytes, protein, glucose, ketones, bilirubin, urobilinogen, nitrite, erythrocyte/hemoglobin (Hb), and the pH were assessed using a urine dipstick (Combur-Test®). Combined calcium and magnesium (Ca/Mg) content were evaluated with the Total Hardness Test. The AmniSure test, which detects rupture of fetal membranes in women on the basis of the presence of human placental alpha microglobulin-1, was also performed on canine AMF, ALF, and urine. Data were analyzed using the Fisher's exact test, Wilcoxon signed-rank test, and Pearson's correlation. Sensitivity, specificity, and positive and negative likelihood ratios (LR) were calculated for parameters with significant difference between urine and both fetal fluids. Maternal urine had higher SG and lower leukocyte, protein, Hb, and Ca/Mg content than AMF and ALF. Glucose was more often present in AMF (n = 17) and ALF (n = 12) than in urine (n = 1), whereas ketone bodies were rarely detected in ALF compared with urine. Bilirubin content was higher in urine and ALF than in AMF. AMF pH was less variable and higher than the pH of ALF or urine. The AmniSure was negative in all samples tested. Sensitivity and specificity for SG and for the detection of leukocytes, protein, glucose, Hb, Ca/Mg, and glucose without ketones in urine and fetal fluids were between 42% to 100% and 65% to 100%, respectively. Best positive LR was achieved for the detection of glucose without ketones and best negative LR for SG of 1.022 or less. In conclusion, the AmniSure test, which is used in humans with high diagnostic accuracy, cannot identify AMF and ALF in dogs. On the basis of our results in 26 dogs undergoing Cesarean section, the presence or absence of fetal fluids could be best determined by a positive glucose test without ketone bodies or by SG higher than 1.022, respectively. These tests may serve as additional tools to recognize parturition if clear-yellowish vulvar discharge is present in a term pregnant bitch, but their accuracy and practicability in the clinical setting need to be confirmed.

Endocrine control of canine mammary neoplasms: serum reproductive hormone levels and tissue expression of steroid hormone, prolactin and growth hormone receptors.

BACKGROUND: Neoplasms of the mammary gland are among the most common diseases in female domestic dogs (Canis familiaris). It is assumed that reproductive hormones influence tumorigenesis in this species, although the precise role of the endocrine milieu and reproductive state is subject to continuing discussion. In line with this, a recent systematic review of available data on the development of mammary neoplasms revealed weak evidence for risk reduction after neutering and an effect of age at neutering. Investigation of several hormone receptors has revealed decreased expression of estrogen receptor-alpha (ERα, ESR1), progesterone (P4) receptor (PGR), prolactin (PRL) receptor (PRLR) and growth hormone receptor (GHR) associated with neoplastic differentiation of mammary tissues. In other studies, increased levels of estrogens, progesterone and prolactin were found in serum and/or tissue homogenates of dogs with malignant neoplasms. However, the association between these entities within one animal population was never previously examined. Therefore, this study investigated the association between circulating serum concentrations of estradiol-17ß, progesterone and prolactin, and gene expression of ERα (ESR1), ERß (ESR2), PGR, PRLR, PRL and GHR, with respect to reproductive state (spayed vs. intact) and cycle stage (anestrus vs. diestrus). Additionally, the expression of E-cadherin (CDH-1) was evaluated as a possible indicator of metastatic potential. RESULTS: For all receptors, the lowest gene expression was found in malignant tumors compared to normal tissues of affected dogs. Steroid levels were not influenced by their corresponding receptor expression in mammary neoplasms, but increased PRL levels were negatively associated with low PRLR gene expression in malignant tumors. The expression of CDH-1 was influenced by tumor malignancy and cycle stage, i.e., the highest gene expression was found in benign mammary tumors in diestrous dogs compared to normal and malignant mammary tissues of anestrous and spayed dogs. CONCLUSIONS: Herein, it has been confirmed that transformation towards malignant neoplasms is associated with significant reduction of gene expression of particular hormone receptors. Only PRLR in malignant tumors seems to be influenced by circulating PRL levels. In dogs, CDH-1 can be used as a prognostic factor; its expression, however, in benign tumors is influenced by cycle stage.

Expression of prolactin receptors in normal canine mammary tissue, canine mammary adenomas and mammary adenocarcinomas.

BACKGROUND: Mammary tumors represent the most common neoplastic disease in female dogs. Recently, the promoting role of prolactin (PRL) in the development of human breast carcinoma has been shown. Possible proliferative, anti-apoptotic, migratory and angiogenic effects of PRL on human mammary cancer cells in vitro and in vivo were suggested. The effects of PRL are mediated by its receptor, and alterations in receptor expression are likely to play a role in tumor development. Currently, not much data is available about prolactin receptor (PRLR) expression in canine mammary tumors. To set the basis for investigations on the role of PRL in mammary tumorigenesis in this species, prolactin receptor expression was evaluated by semi-quantitative real time PCR and immunohistochemistry on 10 formalin-fixed, paraffin-embedded samples each of canine non-neoplastic mammary tissue, mammary adenomas and adenocarcinomas. RESULTS: The highest PRLR expression levels were found in normal mammary tissue, while adenomas, and to an even higher degree adenocarcinomas, showed a significant decrease in prolactin receptor expression. Compared to normal tissue, PRLR mRNA was reduced 2.4 fold (p = 0.0261) in adenomas and 4.8 fold (p = 0.008) in adenocarcinomas. PRLR mRNA expression was significantly lower in malignant than in benign lesions (p = 0.0165). Immunohistochemistry demonstrated PRLR expression in all three tissue types with signals mostly limited to epithelial cells. CONCLUSIONS: Malignant transformation of mammary tissue was associated with a decline in prolactin receptor expression. Further studies are warranted to address the functional significance of this finding.

Luteal and placental function in the bitch: spatio-temporal changes in prolactin receptor (PRLr) expression at dioestrus, pregnancy and normal and induced parturition.

BACKGROUND: Endocrine mechanisms governing canine reproductive function remain still obscure. Progesterone (P4) of luteal origin is required for maintenance of pregnancy. Corpora lutea (CL) are gonadotrop-independent during the first third of dioestrus; afterwards prolactin (PRL) is the primary luteotropic factor. Interestingly, the increasing PRL levels are accompanied by decreasing P4 concentrations, thus luteal regression/luteolysis occurs in spite of an increased availability of gonadotropic support. PRL acts through its receptor (PRLr), the expression of which has not yet been thoroughly investigated at the molecular and cellular level in the dog. METHODS: The expression of PRLr was assessed in CL of non-pregnant dogs during the course of dioestrus (days 5, 15, 25, 35, 45, 65 post ovulation; p.o.) as well as in CL, the utero/placental compartments (Ut/Pl) and interplacental free polar zones (interplacental sites) from pregnant dogs during the pre-implantation, post-implantation and mid-gestation period of pregnancy and during the normal and antigestagen-induced luteolysis. Expression of PRLr was tested by Real Time PCR, immunohistochemistry and in situ hybridization. RESULTS: In non-pregnant CL the PRLr expression was significantly upregulated at day 15 p.o. and decreased significantly afterwards, towards the end of dioestrus. CL of pregnancy showed elevated PRLr expression until mid gestation while prepartal downregulation was observed. Interestingly, placental but not interplacental expression of PRLr was strongly time-related; a significant upregulation was observed towards mid-gestation. Within the CL PRLr was localized to the luteal cells; in the Ut/Pl it was localized to the fetal trophoblast and epithelial cells of glandular chambers. Moreover, in mid-pregnant animals treated with an antigestagen, both the luteal and placental, but not the uterine PRLr were significantly downregulated. CONCLUSIONS: The data presented suggest that the luteal provision of P4 in both pregnant and non-pregnant dogs may be regulated at the PRLr level. Furthermore, a role of PRL not only in maintaining the canine CL function but also in regulating the placental function is strongly suggested. A possible functional interrelationship between luteal P4 and placental and luteal PRLr expression also with respect to the prepartal luteolysis is implied.

Design of correlation filters for recognition of linearly distorted objects in linearly degraded scenes.

Generalized correlation filters are proposed to improve recognition of a linearly distorted object embedded in a nonoverlapping background when the input scene is degraded with a linear system and additive noise. Several performance criteria defined for the nonoverlapping signal model are used for the design of filters. The derived filters take into account information about an object to be recognized, disjoint background, noise, and linear degradations of the target and the input scene. Computer simulation results obtained with the proposed filters are discussed and compared with those of various correlation filters in terms of discrimination capability, location errors, and tolerance to input noise.

Evaluation of the repeatability of rhinomanometry and its use in assessing transnasal resistance and pressure in dogs.

OBJECTIVE: To evaluate a modified posterior rhinomanometric method for clinical application in dogs. ANIMALS: 15 healthy Beagles and 8 Bulldogs (4 healthy and 4 with respiratory problems). PROCEDURES: Rhinomanometry was performed 3 times within a 15-minute period in anesthetized dogs. Transnasal pressure (P(NA)) and nasal resistance (R(NA)) were determined by use of artificial airflow (adjusted for body weight) for inspiration (P(NAin) and R(NAin), respectively) and expiration (P(NAout) and R(NAout)). Procedures were repeated for the Beagles 7 days later. RESULTS: For the Beagles, mean +/- SD of P(NAin) for both days (0.162 +/- 0.042 kPa) was significantly lower than P(NAout) (0.183 +/- 0.053 kPa). Similarly, R(NAin) (1.47 +/- 0.41 kPa/[L/s]) was significantly lower than R(NAout) (1.64 +/- 0.46 kPa/[L/s]). Pairwise comparison of values for P(NA) and R(NA) for the 2 days revealed no significant difference. Repeatability of the method (estimated as within-day variation) for R(NA) was +/- 0.19 kPa/(L/s), whereas variation between the days was +/- 0.36 kPa/(L/s) for R(NAin) and +/- 0.44 kPa/(L/s) for R(NAout). The 4 clinically normal Bulldogs had R(NA) values ranging from 1.69 to 3.48 kPa/(L/s), whereas in the 4 Bulldogs with respiratory problems, R(NA) ranged from 9.83 to 20.27 kPa/(L/s). CONCLUSIONS AND CLINICAL RELEVANCE: R(NA) is inversely dependent on body size and nonlinearly associated with airflow. We propose that R(NA) in dogs should be determined for airflows standardized on the basis of body size. The P(NA) and R(NA) in Beagles can be measured with sufficient repeatability for clinical use and nasal obstructions are detectable.