Computed tomography and radiographic lymphography of the thoracic duct by subcutaneous or submucosal injection

A simple method of lymphography of the thoracic duct was investigated. Using three female beagles, contrast media were administered rectally, vaginally and into the perianal tissue. The administration sites were gently massaged, and imaging was carried out at constant intervals using computed tomography and radiograph. Moreover, Indian ink was administered into the rectum mucous membrane in dogs for proof of this method of lymphography, and the lymph drainage routes were observed. The investigation showed that clear computed tomography and radiographic contrast images of the thoracic duct were obtained by subcutaneous and submucosa injection of angiography contrast medium and 3D processing of these images revealed the three-dimensional positions and course of the thoracic duct and cisterna chyli.     

Evaluation of a PCR-restriction fragment length polymorphism (PCR-RFLP) assay for molecular epidemiological study of Shiga toxin-producing Escherichia coli

In this study, we have evaluated our recently developed polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay for the molecular subtyping of Shiga toxin-producing Escherichia coli (STEC). A total of 200 STEC strains including O157 (n=100), O26 (n=50), O111 (n=10), and non-O26/O111/O157 (n=40) serogroups isolated during 2005-2006 in Japan, which were identified to be clonally different by pulsed-field gel electrophoresis (PFGE) were further analyzed by the PCR-RFLP assay in comparison to PFGE. Ninety-five of O157, 48 of O26, five of O111 and 19 of non-O26/O111/O157 STEC strains yielded one to three amplicons ranging from 6.0 to 15.5 kb in size by the specific primer set targeting region V which is located in the upstream of stx genes. These strains were classified into 41 (O157), 8 (O26), 4 (O111) and 17 (non-O26/O111/O157) groups based on the RFLP patterns obtained by subsequent restriction digestion, respectively. Although the discriminatory power of PCR-RFLP assay was somewhat less than that of PFGE, it is more convenient for molecular subtyping of STEC strains especially for O157, the most important serogroup implicated in human diseases, as well as to identify the outbreak-associated isolates because of its simplicity, rapidity, ease and good reproducibility.     

Effects of 3-methyl-4-nitrophenol in diesel exhaust particles on the regulation of reproductive function in immature female Japanese quail (Coturnix japonica)

In a previous study, we found that 3-methyl-4-nitrophenol (PNMC), a component of diesel exhaust particles and also a degradation product of the insecticide fenitrothion, exhibits reproductive toxicity in the adult male Japanese quail. The present study investigated the toxicity of PNMC in the female Japanese quail and its ability to influence reproduction in immature females. The quail (21-day-old) were injected intramuscularly (im) with PNMC at doses 0.1, 1 or 10 mg/kg body weight daily for 3 days. There was no significant difference in body growth between the PNMC-administered and control birds. However, the weights of the oviducts were significantly lower in the PNMC-treated birds at all doses. Furthermore, the plasma concentrations of luteinizing hormone (LH) and estradiol-17 beta were significantly decreased with 1 and 10 mg/kg of PNMC. These findings suggest that PNMC might influence the hypothalamo-pituitary-gonadal axis with decreasing in secretion of GnRH, LH and ovarian steroid hormones and subsequently disturb growth of the reproductive organs of immature female quail. This study indicates that PNMC induces reproductive toxicity at the central level and disrupts reproductive function in the immature female quail.     

A canine case of skull base meningioma treated with hydroxyurea

An 11-year-old female miniature schnauzer was tentatively diagnosed with the skull base meningioma, based on several examinations. Because surgical treatment was difficult, and outpatient radiation therapy was not available in the local area, chemotherapy with hydroxyurea combined with dexamethasone was selected. The patient's clinical symptoms improved after one week of treatment, and the tumor size was obviously reduced on MRI performed 37 days after treatment began. The patient received hydroxyurea for 7 months, with symptoms remaining stable, and the tumor re-increased to almost the same size at 7 months as that at the initial examination. At that time, hydroxyurea was discontinued. The patient died from pulmonary edema 14 months after treatment began. Pathologically, the tumor was diagnosed as a meningioma.     

Gonadal morphogenesis and sex differentiation in cultured chub mackerel,Scomber japonicus

The timing of primordial germ‐cell (PGC) migration with regard to the gonadal anlagen, gonad formation and sex differentiation was examined histologically in the chub mackerel (Scomber japonicus) at 5–190 days post hatching (dph). At 5 dph, PGCs appeared on the peritoneal epithelium surface or in the mesentery, on the dorsal side of the abdominal cavity. By 10 dph, stromal cells around the PGCs proliferated. The gonadal primordium was formed by 15 dph. The gonadosomatic index was 0.01% at 30 dph and increased thereafter (0.32% in females and 0.04% in males at 160 dph). Ovarian differentiation occurred at 30–40 dph, indicated by ovarian cavity formation (elongation and fusion of the upper and lower ovarian edges). Meiosis was subsequently initiated. A few meiotic oocytes surrounded the cavity at 50 dph; most were in the perinucleolus stage at 60 dph and attained a diameter of 60–70 μm at 190 dph. Testicular differentiation occurred at 30 dph, indicated by the formation of the sperm duct primordium. Spermatogonia gradually proliferated, developing into spermatocytes at the chromatin–nucleolus stage (after 90 dph) and subsequently into spermatids and spermatozoa (160 dph). These data could aid the development of seeding and cell‐engineering technologies for scombrid fish.     

Is experience on a farm an effective approach to understanding animal products and the management of dairy farming?

The understanding of animal products and dairy farming is important for the promotion of dairy farming. Thus, to examine the effects of farm experience on the understanding of animal products and the management of dairy farming, the interaction between students and dairy cows was investigated in groups of first‐year veterinary nursing students in 2011 and 2012 (n = 201). These students included 181 women and 20 men. Nine items about dairy cows were presented in a questionnaire. The survey was performed before and after praxis on the educational farm attached to the authors' university. After praxis on the farm, increases occurred in the number of positive responses to the items involving the price of milk, dairy farming and the taste of milk. For these items, a significant difference (P < 0.05) was found between the scores obtained before and after training. The results of the study suggested that farm experience is useful for improving the understanding of animal products and dairy farming.     

Hair cortisol levels of lactating dairy cows in cold‐ and warm‐temperate regions in Japan

We compared the hair cortisol levels of lactating dairy cows in a cold‐ and a warm‐temperate region out of four climatic zones in Japan. We simultaneously investigated the effects of calving number, lactation period and month of hair sampling. Hair of nine Holstein lactating cows chosen from each region (i.e. 18 cows per sampling) was sampled in March, June, September and December. Number of calvings (1, 2, ≥3) and lactation duration (early: <100, middle: 101–200, and late: >201 days) were balanced between regions. Cortisol was extracted from hair by methanol, and its level was determined with a cortisol immunoassay kit. A multi‐way analysis of variance revealed that the effects of month of hair sampling (P < 0.001) and its combination with region (P < 0.05) were significant. In a multiple comparison test, significant differences (P < 0.01) in hair cortisol level (pg/mg of hair) were found between June (13.0 ± 1.0) and the other 3 months, and between September (1.6 ± 0.2) and December (4.5 ± 0.3). The rise in cortisol level from March to June was more intense in the cold‐temperate region. These results demonstrate the necessity of considering seasonal variations in each climatic region when we use hair cortisol level as an indicator of stress.     

Evidence for estrogen receptor expression during medullary bone formation and resorption in estrogen-treated male Japanese quails (Coturnix coturnix japonica)

The temporal expression of estrogen receptor (ER)-α and ER-β mRNA was examined in male Japanese quails. Femurs of quails receiving 17β-estradiol underwent RTPCR and histochemical analysis 1 to 15 days after treatment. Untreated quails were used as controls (day 0). Between days 0 and 5, cells lining the bone endosteal surface differentiated into osteoblasts, which in turn formed medullary bone. Expression of ER-α was already observed on day 0 and increased slightly during bone formation whereas ER-β was hardly detected throughout this process. After osteoclasts appeared on the medullary bone surface, this type of bone disappeared from the bone marrow cavity (days 7~15). ER-α expression simultaneously decreased slightly and ER-β levels remained very low. These results suggest that estrogen activity mediated by ER-α not only affects medullary bone formation but also bone resorption.     

Molecular cloning of gonadotropin cDNA in sevenband grouper, Epinephelus septemfasciatus

The cDNA for glycoprotein hormone (GPH) α-subunit, β-subunits of the FSH (GtH I) and LH (GtH II) were isolated, cloned, and sequenced from sevenband grouper pituitary using RACE PCR. These results show that sevenband grouper has two different types of gonadotropins FSH (GtH I) and LH (GtH II), as other teleosts.     

Fine structure and differentiation of the alimentary canal in captive-bred Japanese eel Anguilla japonica preleptocephali

ABSTRACT:   The fine structure of the alimentary canal in preleptocephali produced by artificially matured Japanese eel was examined. At 1 day posthatch (dph), the alimentary canal was found only above the dorsal side of the yolk mass, and the epithelium was composed of a single layer of epithelial cells. By 5 dph, the alimentary canal was divided into three segments based on the structure of the epithelial cells: foregut, midgut and hindgut, corresponding to the future esophagus, intestine and rectum, respectively. After 7 dph, the epithelium in the foregut was surrounded by a circular muscle layer, suggesting a role in the transportation of food materials. The epithelial cells of the midgut exhibited well-developed membranous structures, which are deduced to be invaginations of the cytoplasmic membrane. Pinocytotic invaginations and vacuoles were observed in the epithelial cells of the hindgut; this observation suggests that this region is involved in the uptake of food. Significant changes in morphological features of the epithelial cells in each segment were observed until 7 dph; however, these were not evident between 7 dph and 13 dph. Consequently, the differentiation of the alimentary canal was completed by 7 dph, and preleptocephalus had developed the ability to absorb food by 7 dph.