Naturally occurring Tyzzer's disease in a calf.

Naturally occurring Clostridium piliforme infection (Tyzzer's disease) was found in a calf. Light microscopic examination revealed multifocal coagulative necrosis in the liver, catarrhal gastroenteritis, tracheitis and pneumonia, and thymic atrophy. Warthin-Starry staining clearly showed large filamentous bacilli in bundles or criss-cross patterns within the hepatocytes and epithelium and smooth muscle cells of the ileum and cecum. Immunohistochemistry using anti-C. piliforme RT and MSK strain antisera showed positive reaction against the bacilli. Electron microscopic examination revealed bacilli within the hepatocytes that demonstrated a characteristic vegetative form, with peritrichous flagella, and spores. The polymerase chain reaction (PCR) study using the paraffin-embedded liver sections, the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme was amplified. The characteristics of these bacilli are consistent with those of of C. piliforme. The PCR technique using paraffin-embedded sections should be useful for confirming C. piliforme infection in spontaneous cases.     

The first production of glass eel in captivity: fish reproductive physiology facilitates great progress in aquaculture

Weekly injections of salmon pituitary extracts (SPE) were administered to female Japanese eel, Anguilla japonica at a dose of 20 mg/fish. This induced vitellogenesis and caused oocytes to reach the migratory nucleus stage. Later, a majority of the females that received an injection of SPE at a priming dose, followed 24 h later by 17,20β-dihydroxy-4-pregnen-3-one (DHP), ovulated 15 to 18 h after the final injection. In cultivated males, repeated injections of human chorionic gonadotropin (hCG) at a dose of 1 IU/g BW/week induced spermatogenesis and spermiation. Since potassium ions were revealed to be an essential constituent for the maintenance of motility in the eel spermatozoa, artificial seminal plasma containing KCl was designed as a diluent of milt, and enabled the preservation of milt for several weeks in refrigeration. As a result, artificial fertilization performed immediately after ovulation with pre-diluted and stocked milt consistently resulted in the production of high-quality gametes. Recently, a slurry-type diet made from shark egg yolk has been found to be a suitable feed for captive-bred eel larvae. Although preleptocephalus larvae can be reared with this diet beyond the depletion of their yolk and oil droplet stores, it remains inadequate because larvae reared under this way cannot be raised to the following stage. Therefore, the diet was improved by supplements of krill hydrolysate, soybean peptide, vitamins and minerals. Larvae fed on this new diet have grown to 50 to 60 mm in total length (TL), and have begun to metamorphose into glass eels approximately 250 days after hatching.     

Natural infection with canine distemper virus in a Japanese monkey (Macaca fuscata)

A case of encephalitis in a Japanese monkey (Macaca fuscata) was examined histopathologically and serologically. The animal had brain lesions consisting of perivascular cuffs, malacia, inclusion bodies and giant cells. Monoclonal antibody to the nucleoprotein of canine distemper virus (CDV) stained the inclusions, and the distribution of the virus antigen was closely associated with that of the histological lesions. Serologically, all the 22 monkeys in the same group as the diseased monkey had relatively high titers of neutralizing antibody to CDV, but not to measles virus (MV). The pattern of the antibody titers to CDV and MV closely resembled that of cynomolgus monkeys experimentally inoculated with CDV, but differed from that of monkeys inoculated with MV. These findings suggest that an epidemic of CDV occurred in these Japanese monkeys, associated with one case of fatal viral encephalitis. This is believed to be the first report of a natural infection by CDV in non-human primates.     

Perirenal pyelocaliceal diverticulum in an infant cat

A 3-month-old female tortoise-shell cat showing azotemia died with a marked swollen abdomen. Necropsy revealed a huge perirenal cyst (8.5 x 6.0 x 4.5 cm) on the ventral aspect of the right kidney. The cyst was filled with the pellucid yellow fluid with a smell of urine. The lumen was connected with irregularly dilated renal pelvis by a narrow channel passing through the renal parenchyma. The cyst was lined by epithelial cells and its wall was consisted of collagen fibers and smooth muscle cells as that of the renal pelvis and ureter. Renal parenchyma adjacent to the channel showed interstitial infiltration of the lymphoid cells. The cyst was a diverticulum of the renal pelvis due to an impaired development.     

The effect of colostrum ingestion during the first 24 hours of life on early postnatal development of piglet immune systems

It has been suggested that colostrum is important not only for direct protection from pathogens but also for proper development of immune systems in piglets. In this study, we focused on the effect of colostrum ingestion during the first 24 h of life on early postnatal development of piglet immune systems. Thirty‐six piglets from five litters were divided into colostrum‐fed (CoF) and colostrum‐deprived (CoD) groups. The former group was allowed to suckle normally while formula milk was fed to the latter group during the first 24 h of life. At the weaning period, the concentrations of fecal immunoglobulin (Ig) A and plasma IgG as well as the number of blood leukocyte subsets were analyzed. Fecal IgA and plasma IgG concentrations in the CoF group were more than twice as high as those in the CoD group (P < 0.01). In addition, the number of blood B cells was significantly higher in the CoF group than that in the CoD group (P < 0.05). This study demonstrates that colostrum ingestion during the first 24 h plays a significant role in early postnatal development of both mucosal and systemic immunity of piglets.     

Antiatherogenic effect of isoflavones in ovariectomized apolipoprotein e-deficient mice

The consumption of isoflavone-containing foods such as soybean and soybean products has been reported to have beneficial effects on the cardiovascular system in postmenopausal women. The present study was carried out to examine the mechanism underlying the beneficial effects of isoflavones in apolipoprotein (apo) E-deficient mice subjected to ovarian resection. Compared with sham-operated mice, ovariectomized mice had a larger arterial lesion area in the aortic root. Feeding the ovariectomized mice an isoflavone-containing diet (0.055 mg/kJ of total isoflavones/cal of diet) reduced the size of these lesions more than did feeding them with an isoflavone-free diet. Neither ovariectomy nor diet had a significant effect on the concentration of cholesterol in serum and urinary levels of isoprostanes, which are biomarkers for oxidative stress in vivo. The ovariectomized mice showed a greater increase in mRNA abundance for monocyte chemoattractant protein (MCP)-I in the aorta and in the level of nitric oxide (NO) secreted by peritoneal macrophages in culture than did the sham-operated mice. The isoflavone-containing diet lowered the MCP-I expression and the NO secretion more than did the isoflavone-free diet. These results suggest that dietary isoflavones confer an antiatherogenic effect by preventing the activation of macrophages due to the removal of ovaries.