Induction of short-term pseudopregnancy in gilts by the administration of estradiol benzoate or estradiol dipropionate to achieve ovulatory synchronization for embryo collection

A study was conducted to investigate whether ovulation in gilts could be synchronized for embryo collection by the administration of estradiol benzoate (EB) or estradiol dipropionate (EDP) to induce pseudopregnancy, followed by the treatment with prostaglandin F_2α (PGF_2α) on 10 days after. Ten gilts each received a total of 20 mg of EB or EDP on Day 10 or EB on Day 10 and 14 to induce pseudopregnancy (Day 0 = onset of estrus). Donors received PGF_2α 10 or 15 days (as a control) after the first administration of estrogens and subsequently eCG and hCG, and were then inseminated artificially. The embryos were collected 7 days after the administration of hCG, and assessed for embryo yield and their developmental stages. All protocols resulted in good embryo yield (9.8–13.2 embryos in average), and the embryos showed average ability to develop to the expanded blastocyst stage (3.29–4.03 as developmental scores) without any significant differences among the protocols. These results suggest that the administration of PGF_2α 10 days after the treatment of gilts with EB or EDP would allow synchronization of ovulation and embryo collection, as well as shortening the period from estrus detection to embryo collection, thus improving embryo collection efficiency.     

Malignant Mesothelioma in the Thoracic Cavity of a Crj:CD(SD) Rat Characterized by Round Hyalinous Stroma

Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers.     

Dose assessment of 2% chlorhexidine acetate for canine superficial pyoderma

The dose of 2% chlorhexidine acetate (2CA; Nolvasan^® Surgical Scrub; Fort Dodge Animal Health, Fort Dodge, IA, USA) for canine superficial pyoderma was evaluated. The first trial compared three doses (group 1, 57 mL/m² body surface area; group 2, 29 mL/m² body surface area; and group 3, 19 mL/m² body surface area) in a randomized, double‐blind, controlled fashion. Twenty‐seven dogs with superficial pyoderma were treated with 2CA at the allocated doses every 2 days for 1 week. The owners and investigators subjectively evaluated the dogs, and investigators scored skin lesions, including erythema, papules/pustules, alopecia and scales, on a 0–4 scale. There were no significant differences in response between the treatment groups. The second trial established a practical dose‐measuring method for 2CA. Sixty‐eight owners were asked to apply 2CA on their palm in an amount corresponding to a Japanese ¥500 coin, 26.5 mm in diameter. This yielded an average dose of 0.90 ± 0.40 mL. Mathematically, the doses used in groups 1, 2 and 3 can be represented as one coin per approximately one‐, two‐ and three‐hand‐sized lesions, respectively. The results therefore suggest that owners instructed to apply one coin of the product per two‐hand‐sized areas of superficial pyoderma would use the range of doses evaluated in this trial.     

Trichomoniasis in finches from the Canadian Maritime provinces — An emerging disease

Trichomoniasis was diagnosed in multiple incidents of mortality in wild purple finch (Carpodacus purpureus) and American goldfinch (Carduelis tristis) in the Canadian Maritimes. Birds exhibited regurgitation, emaciation, and hyperplastic oropharyngitis, ingluvitis, and esophagitis. Trichomonas gallinae was identified by histopathology and polymerase chain reaction (PCR). Trichomoniasis (trichomonosis) is an emerging disease in wild finches of eastern Canada.     

Natural zeolites in diet or litter of broilers

1. This study aims to analyse the influence of adding natural zeolites (clinoptilolite) to the diet or litter of broilers and their effects on growth performance, carcass yield and litter quality.

2. Three consecutive flocks of broilers were raised on the same sawdust litter, from d 1 to d 42 of age, and distributed in three treatments (control with no added zeolites, addition of 5 g/kg zeolite to diet and addition of 100 g/kg zeolites to litter).

3. The addition of zeolites to the diet or litter did not affect growth performance or carcass yield.

4. The addition of zeolites to the diet did not influence moisture content of the litter, ammonia volatilisation was reduced only in the first flock and pH of litter was reduced in the second and third flock.

5. However, the addition of zeolites to the litter reduced moisture content, litter pH and ammonia volatilisation in all flocks analysed.

6. The addition of 5 g/kg zeolite to the diet in three consecutive flocks was not effective in maintaining litter quality, whereas the addition of 100 g/kg natural zeolites to sawdust litter reduced litter moisture and ammonia volatilisation in three consecutive flocks raised on the same litter.

     

Mead acid supplementation does not rescue rats from cataract and retinal degeneration induced by N-methyl-N-nitrosourea

Fatty acids and their derivatives play a role in the response to ocular disease. Our current study investigated the effects of dietary mead acid (MA, 5,8,11-eicosatrienoic acid) supplementation on N-methyl-N-nitrosourea (MNU)-induced cataract and retinal degeneration in Sprague-Dawley rats. Experiment 1 was designed to inhibit cataract formation, with the dams fed a 2.4% MA or basal (<0.01% MA) diet during lactational periods. On postnatal day 7, male pups received a single intraperitoneal (ip) injection of 50 mg/kg MNU or vehicle. Lens opacity and morphology were examined 7 and 14 days after the MNU injection. Experiment 2 was designed to inhibit retinal degeneration and was performed with female postweaning rats. In this experiment, dams were fed the 2.4% MA or basal diet during the lactational periods. Thereafter, the female pups were continuously fed the same diets during their postweaning periods. On postnatal day 21 (at weaning), pups received a single ip injection of 50 mg/kg MNU. Retinal morphology was examined 7 days after the MNU injection. In experiment 3, six-week-old female rats were fed the 2.4% MA or basal diet starting at one week before the MNU injection and were then continuously fed the same diets until sacrifice. Rats at 7 weeks of age were given a single ip injection of 40 mg/kg MNU, and the retina was then examined morphologically one week after the MNU injection. In experiment 1, mature cataract was found in all of the MNU-treated groups, with or without MA supplementation. In experiments 2 and 3, atrophy of both the peripheral and central outer retina occurred in all rats exposed to MNU, with or without MA supplementation, respectively. The severities of the cataracts and retinal atrophy in the rats were similar regardless of MA supplementation. Dietary mead acid, which is used as a substitute in essential fatty acid deficiency in the body, does not modify MNU-induced cataract and retinal degeneration in rat models.     

Histopathological and Immunohistochemical Characterization of Spontaneously Occurring Uterine Deciduomas in Young Adult Rats

Uterine deciduomas were found in two female virgin rats, a 15-week-old Lewis rat and a 7-week-old Sprague-Dawley rat. The firm white nodules were located at the base of unilateral uterine horns and were approximately 6 mm and 4 mm in diameter. Histopathologically, the nodules were composed of three areas, each with a distinct type of proliferating cells: large epithelioid decidual cells with round nuclei, prominent nucleoli and abundant eosinophilic cytoplasm (antimesometrial region); compact spindle-shaped cells with oval nuclei and vacuolar cytoplasm (transitional region); and pleomorphic and spiny cells with round to oval nuclei and compact eosinophilic cytoplasm (mesometrial region). These cells proliferated in sheet-like arrangements and transformed into the other types of cells located in surrounding regions. Immunohistochemically, proliferating cells in all regions were strongly positive for proliferating cell nuclear antigen. The proliferating cells were positive for vimentin, and large decidual cells were positive for common acute lymphoblastic leukemia antigen 10, a marker of uterine interstitial cells. Large decidual cells were positive for α-smooth muscle actin and desmin, suggesting differentiation into muscular cells. Progesterone receptor was expressed in all cell types; however, estrogen receptor α was not expressed in the antimesometrial region. These extremely rare tumor-like nodules represent nonneoplastic lesions referred as decidual reactions of endometrial interstitial cells, and their biological behavior is that of a space-occupying benign tumor in young rats. Our cases might provide information as a historical control in toxicity and pharmacological studies in rats.     

Stability of the regulatory T cell lineage in vivo

Tissue maintenance and homeostasis can be achieved through the replacement of dying cells by differentiating precursors or self-renewal of terminally differentiated cells or relies heavily on cellular longevity in poorly regenerating tissues. Regulatory T cells (T(reg) cells) represent an actively dividing cell population with critical function in suppression of lethal immune-mediated inflammation. The plasticity of T(reg) cells has been actively debated because it could factor importantly in protective immunity or autoimmunity. By using inducible labeling and tracking of T(reg) cell fate in vivo, or transfers of highly purified T(reg) cells, we have demonstrated notable stability of this cell population under physiologic and inflammatory conditions. Our results suggest that self-renewal of mature T(reg) cells serves as a major mechanism of maintenance of the T(reg) cell lineage in adult mice.     

Coloration of ultra high molecular weight polyethylene fibers using alkyl-substituted anthraquinoid blue dyes

UHMWPE fibers were dyed with a series of anthrquinoid blue dyes having different length of alkyl substituents at general dyeing condition. The dyeability was investigated at various conditions and fastness of the dyeings was examined. As the length of alkyl substituents increased, the dyeability toward UHMWPE fibers tends to be improved gradually. Color strength of the fabrics was increased with the increase of dyeing temperature from 100 to 130 °C. From the dyeing rate, equilibrium dyeing at 130°C was achieved at 2–3 h. The tensile strength of UHMWPE fibers after dyeing at 130 °C for 1 h was maintained at a level of 95 % of untreated fiber. However, at prolonged dyeing time at 130 °C, the tensile strength was significantly decreased to a practically unacceptable level. The color fastnesses to washing, rubbing and light of the dyeings were very good showing higher than 4 ratings.     

Variation in Baiting Intensity Among CO2-Baited Traps Used to Collect Hematophagous Arthropods

Hematophagous arthropods transmit the etiological agents of numerous diseases and as a result are frequently the targets of sampling to characterize vector and pathogen populations. Arguably, the most commonly used sampling approach involves traps baited with carbon dioxide. We report results of a laboratory study in which the performance of carbon dioxide-baited traps was evaluated using measures of baiting intensity, the amount of carbon dioxide released per unit time during trap deployment. We evaluated the effects of trap design, carbon dioxide source, and wind speed on baiting intensity and documented significant effects of these factors on the length of sampling (time to baiting intensity = 0), maximum baiting intensity, and variation in baiting intensity during experimental trials. Among the three dry ice-baited trap types evaluated, traps utilizing insulated beverage coolers as dry ice containers sampled for the longest period of time, had the lowest maximum but most consistent baiting intensity within trials and were least sensitive to effects of wind speed and dry ice form (block vs. pellet) on baiting intensity. Results of trials involving traps baited with carbon dioxide released from pressurized cylinders suggested that this trap type had performance comparable to dry ice-baited insulated cooler traps but at considerably higher cost.