Effects of dietary phytoestrogens on plasma testosterone and triiodothyronine (T3) levels in male goat kids

Background

Exposure to xenoestrogens in humans and animals has gained increasing attention due to the effects of these compounds on reproduction. The present study was undertaken to investigate the influence of low-dose dietary phytoestrogen exposure, i.e. a mixture of genistein, daidzein, biochanin A and formononetin, on the establishment of testosterone production during puberty in male goat kids.

Methods

Goat kids at the age of 3 months received either a standard diet or a diet supplemented with phytoestrogens (3 - 4 mg/kg/day) for ~3 months. Plasma testosterone and total and free triiodothyronine (T₃) concentrations were determined weekly. Testicular levels of testosterone and cAMP were measured at the end of the experiment. Repeated measurement analysis of variance using the MIXED procedure on the generated averages, according to the Statistical Analysis System program package (Release 6.12, 1996, SAS Institute Inc., Cary, NC, USA) was carried out.

Results

No significant difference in plasma testosterone concentration between the groups was detected during the first 7 weeks. However, at the age of 5 months (i.e. October 1, week 8) phytoestrogen-treated animals showed significantly higher testosterone concentrations than control animals (37.5 nmol/l vs 19.1 nmol/l). This elevation was preceded by a rise in plasma total T₃ that occurred on September 17 (week 6). A slightly higher concentration of free T₃ was detected in the phytoestrogen group at the same time point, but it was not until October 8 and 15 (week 9 and 10) that a significant difference was found between the groups. At the termination of the experiment, testicular cAMP levels were significantly lower in goats fed a phytoestrogen-supplemented diet. Phytoestrogen-fed animals also had lower plasma and testicular testosterone concentrations, but these differences were not statistically significant.

Conclusion

Our findings suggest that phytoestrogens can stimulate testosterone synthesis during puberty in male goats by increasing the secretion of T₃; a hormone known to stimulate Leydig cell steroidogenesis. It is possible that feedback signalling underlies the tendency towards decreased steroid production at the end of the experiment.     

Retinal degeneration in nine Swedish Jämthund dogs

The Jämthund is the fourth most common breed in Sweden with approximately 1600 pups registered each year. Although it has been known that some adult dogs go blind, so they cannot hunt, the Jämthund dog has historically not been screened for hereditary eye diseases. This report describes nine Swedish Jämthund dogs with retinal degeneration. These dogs represent all Jämthund dogs diagnosed with progressive retinal atrophy (PRA) by the Swedish Eye Panel and registered with the Swedish Kennel Club from January 1998 to September 2008. The dogs were examined with indirect opthalmoscopy and slitlamp biomicroscopy. Additionally, electroretinograms (ERGs) following ECVO guidelines were performed in two dogs (one affected and one normal) and the eyes from three affected dogs were examined by light‐microscopy postmortem. Typical findings were bilateral symmetric generalized retinal degeneration with tapetal hyper‐reflectivity, attenuation of blood vessels and pigment clumping in the nontapetal fundus. These retinal findings progressed with time in two dogs after re‐examination. Visual impairment, especially under dim light conditions, was observed in the affected dogs. ERG from one affected dog showed profoundly reduced rod responses, whereas cone responses were better preserved. Microscopic changes in the eyes from three dogs were characterized by a severe diffuse predominantly outer retinal degeneration and atrophy. Re‐sequencing of the prcd‐gene for eight of the nine investigated dogs revealed that none of the individuals carried disease allele that has been associated with prcd‐PRA in other breeds. In conclusion, ophthalmoscopic, electroretinographic, and light‐microscopic alterations observed in nine Jämthund dogs were compatible with PRA. The prcd mutation was excluded as a cause of this retinopathy.     

The yin and yang of corpus luteum-derived endothelial cells: balancing life and death

A dense network of capillaries irrigates the corpus luteum (CL) allowing an intricate cross talk between luteal steroiodgenic and endothelial cell (EC) types. Indeed, luteal endothelial cells (LEC) play pivotal roles throughout the entire CL life-span. Microvascular endothelial cells are locally specialized to accommodate the needs of individual tissues, therefore unraveling the characteristics of LEC is imperative in CL physiology. Numerous studies demonstrated that endothelium-derived endothelin-1 (ET-1) is upregulated by the luteolytic hormone-prostaglandin F2alpha (PGF2alpha) and functions as an important element of the luteolytic cascade. To have a better insight on its synthesis and action, members of ET system (ET-1, ET converting enzyme -ECE-1 and ET(A) and ET(B) receptors) were quantified in LEC. The characteristic phenotype of these cells, identified by high ET-1 receptor expression (both ET(A), ET(B)) and low ET-1 and ECE-1 levels, was gradually lost during culture suggesting that luteal microenvironment sustains the selective phenotype of its resident endothelial cells. Proper vascularization and endothelial cell activity per se are essential for normal CL function. Therefore, factors affecting vascular growth are expected to play major role in the regulation of luteal function. Concomitantly with the angiogenic process, luteal PGF2alpha and its receptors (PGFR) are induced and maintained during most of the CL life-span, suggesting a possible role of PGF2alpha in LEC proliferation and function. Dispersed LEC expressed PGFR and incubation with the prostaglandin stimulated mitogen-activated protein kinase (MAPK) signaling cascade. PGF2alpha activated p42/44 MAPK phosphorylation also in long-term cultured LEC. In this cell type, PGF2alpha increased cell number, 3H-Thymidine incorporation and cell survival. Additionally, PGF2alpha rapidly and transiently stimulated the expression of immediate-early response genes, i.e. c-fos and c-jun mRNA, further suggesting a mitogenic effect for this prostaglandin in LEC. These data imply that PGF2alpha may assume different and perhaps opposing roles depending on luteal microenvironment.     

Characterization of the bacterial population of the genital tract of adult cats

OBJECTIVE: To characterize the bacteria of the genital tract in adult cats; assess the effect of estrus, mating, and administration of progestins on those microorganisms in females; and evaluate whether results of bacteriologic culture of vaginal swabs are affected by cleansing of the vulva prior to sampling or by repeated sampling. ANIMALS: 66 female and 29 male cats undergoing routine ovariohysterectomy or castration. PROCEDURE: Specimens were obtained from vaginal and uterine or preputial mucosae with swabs moistened with sterile saline (0.9% NaCl) solution. In 9 cats, vaginal specimens were obtained before and after cleansing of the vulva with ethanol; in 7 female cats, 2 vaginal speci mens were obtained in immediate succession. RESULTS: Aerobic bacteria were most commonly isolated from cats' vaginas and prepuces; anaerobic bacteria were isolated frequently from males (41%) but rarely from females (5%). Generally, culture results were not affected by cleansing of the vulva or repeated vaginal sampling. The bacterial population of the vaginas of cats was influenced by stage of the estrous cycle but not by mating or administration of progestins. Bacteria were not isolated from the uterus of any cat. CONCLUSIONS AND CLINICAL RELEVANCE: In cats, bacteria of the genital tract in females are predominantly aerobic; in males, aerobic and anaerobic bacteria are found. The bacterial population of the vagina is affected by stage of the estrous cycle. Pure growth of bacteria in culture of genital tract specimens is a normal finding; antimicrobials should only be administered if clinical signs of genital infection are present.     

Leukocyte endothelial cell interactions in pig to human organ xenograft rejection

In cases where antibody- and complement-mediated hyperacute rejection (HAR) of vascularized organ xenografts has been prevented, acute vascular rejection (AVR) and acute T cell-mediated rejection (ACR) cause graft destruction. Infiltration of leukocytes (innate and graft-primed T cells) into the graft execute the latter two rejection modalities. The leukocyte extravasation process, which is a prerequisite for graft infiltration, is governed by adhesion molecules, including the selectin, integrin and immunoglobulin protein families, and the chemokine protein family. The compatibility between porcine endothelial cell and human leukocyte adhesion molecules was investigated in dynamic adhesion and static transendothelial migration assays. The effect of human anti-pig antibodies on human leukocyte adhesion to, and transendothelial migration across, porcine endothelium was assessed under dynamic and static conditions, respectively. In contrast to previously published results, no difference in the ability of neutrophils to adhere to pig and human endothelium was observed. Furthermore, no evident quantitative or qualitative differences in the capacity of human and porcine endothelium to support transendothelial migration of human leukocytes (T, B and natural killer (NK) cells, monocytes, and neutrophils) could be detected. The presence of human anti-pig antibodies (Abs) modulated the migration of leukocytes across porcine endothelium, as well as neutrophil adhesion to porcine endothelium under conditions of flow. Antibodies specific for pig endothelial adhesion molecules can potentially be used as species (graft)-specific immunosuppressive reagents in order to prevent cellular organ xenograft rejection.     

Effects of management, feeding, and treatment on clinical and biochemical variables in cattle with displaced abomasum

OBJECTIVE: To determine effects of management, feeding, and treatment on clinical and biochemical variables in cows with displaced abomasum (DA). ANIMALS: 374 cows that received 470 treatments for DA. PROCEDURE: Blood and milk samples were obtained from 139 affected cows for analysis; for all cows, clinical data, management, feeding, and treatments were evaluated. RESULTS: Multiparous cows were more predisposed to DA than primiparous cows were, and Swedish Friesians were more predisposed than Swedish Red and Whites were. Eighty percent of cows had left-sided DA, and 20% had right-sided DA. In > 50% of affected cows, clinical signs appeared just before calving to 2 weeks after calving. Incidence of twin calves and periparturient diseases was significantly higher in affected cows than in the overall Swedish cow population. Content of neutral detergent fiber in the silage was low in herds with DA. Feeding a total mixed ration was a risk factor for DA. Treatment by surgical methods gave a significantly higher recovery rate than nonsurgical methods. CONCLUSIONS AND CLINICAL RELEVANCE: Displaced abomasum is a periparturient nutritional disease. Feeding roughage with low neutral detergent content is a more important causative factor than the amount of concentrates fed at the time of calving. The basic principle for prevention of DA is to maintain good ruminal filling before and at calving. The amount of high-quality roughage fed before and at calving should be kept to a minimum. By changing routines for periparturient feeding, it should be possible to reduce the incidence of DA.     

Photocatalytic degradation of pesticides and bio-molecules in water

Two approaches are suggested for the acceleration of the photocatalytic oxidation of organic contaminants of water: acceleration by oxidants and photo-enhancement by dyes. These processes were examined with several substances: two widely applied herbicides, bromacil (a uracil) and metribuzin (a triazine), and three proteins, studied as models of biocontaminated waters. The effects of oxygen and hydrogen peroxide indicated two different reaction patterns of photo-oxidation of the herbicides. With metribuzin, oxygen had a pronounced effect on the rate of photo-oxidation, while the influence of hydrogen peroxide was quite moderate; with bromacil, oxygen had a limited effect on the rate of photo-oxidation, which however was considerably enhanced by hydrogen peroxide. Acceleration of the photo-catalytic oxidation of colourless refractory contaminants by photo-excited dye was observed. Both UV and visible light were required for the enhanced decomposition. The mechanism of the reaction seems to involve a combination of oxidation by hydroxyl radicals, via the hole-electron semiconductor route, with subsequent oxidation of photo-intermediates by singlet oxygen formed by dye sensitization. The TiO2-photocatalyzed oxidation of proteins (albumin, ovalbumin and gamma-globulin) showed the susceptibility of proteins to photocleavage and of the amino acids to photocatalytic degradation. Tyrosine was the most sensitive, while the degradation of the aliphatic amino acids Gly and Asp was slow.     

Concentrations of cardiac Troponin I before and after ovariohysterectomy in 46 female dogs with pyometra

Background

Canine pyometra is a common disease in countries where routine spaying of young dogs is not common practice. This disease is known to lead to systemic inflammation potentially affecting multiple organs in the body, including the heart. Cardiac-specific Troponin I (cTnI) is a sensitive marker of myocardial cell damage, which can result from ischemia, trauma, toxins or inflammation. Dogs with pyometra are also exposed to anaesthesia which can potentially result in myocardial cell damage. The aims of the study were 1) to evaluate the occurrence of myocardial cell damage as indicated by increased serum concentrations of cTnI in dogs with pyometra and relate these to presence of systemic inflammation and 2) to evaluate the change in cTnI-concentrations after anaesthesia and surgery.

Methods

Serum cTnI concentration was measured preoperatively and one day after surgery in 46 female dogs with pyometra and 15 female dogs that underwent surgery for other reasons (ovariohysterectomy and mammary tumours).

Results

Forty-six female dogs of different breeds diagnosed with pyometra were included. The dogs had a median age of 8.5 years (IQR 7.5–10) and a median weight of 29 kg (IQR 9–32). Of the 46 dogs, 37 (80%) fulfilled the chosen criteria for systemic inflammatory response syndrome (SIRS) at inclusion. Thirteen (28%) of the dogs had increased cTnI concentrations (> 0.2 μg/l) before surgery and 18 (39%) had increased cTnI-concentrations the day after surgery. The cTnI concentrations in the 13 dogs with increased preoperative cTnI concentrations decreased in 8 dogs, increased in 4 dogs, and was unchanged in one dog. Seven dogs with nondetectable preoperative cTnI concentrations had increased postoperative concentrations. The only significant association between the studied laboratory or clinical variables (including SIRS) and cTnI concentration was preoperative percentage band neutrophils (PBN) and postoperative cTnI concentration (P = 0.016). In total, 20 dogs (43%) had increased pre- or postoperative cTnI concentrations. Seven dogs (15%) had pre-or postoperative concentrations of cTnI of 1.0 μg/l or higher.

Conclusion

Mild to moderate increases in cTnI appears to be common in dogs with pyometra before and after surgery, but the clinical importance of this finding is uncertain. None of the studied clinical variables were found to reliably predict increased preoperative cTnI concentrations. Because of the pre- and postoperative variation in cTnI concentrations, it was not possible to identify a negative effect of anaesthesia and surgery on myocardial cell integrity.     

Aqueous Pb Reduction in Pb-Contaminated Soils by Florida Phosphate Rocks

Lead contamination is of great environmental concern due to its effect on human health. This study investigated the feasibility of using Florida phosphate rocks (PR) to immobilize aqueous Pb from Pb-contaminated soils. Occidental Chemical PR effectively immobilized Pb from 13 Pb-contaminated soils, but its effectiveness was affected by soil pH and extent of Pb contamination, with aqueous Pb reduction ranging from 21.8 to 100%. Longer reaction times improved aqueous Pb reduction. Six out of 7 Florida PR effectively immobilized aqueous Pb from the Burch Loam soil. Phosphate rock from Cargil Fertilizer was ineffective, with aqueous Pb reduction of 4.73%. The relative effectiveness of 6 Florida PR to immobilize aqueous Pb, excluding Cargil Fertilizer PR, was: Occidental Chemical > CF Chemical > Nu Gulf Industries > Agri-Chemical > IMC > Agrico Chemical. Phosphate rock solubility (as estimated by acid extraction and X-ray diffraction) failed to predicate the effectiveness of PR to immobilize aqueous Pb from Pb-contaminated soils, partially due to the complexity and kinetics of reactions between PR and soils. Our results demonstrate that PR has a potential to cost-effectively treat Pb-contaminated soils.