Experimental transmission of h-type bovine spongiform encephalopathy to bovinized transgenic mice

To characterize the biological and biochemical properties of H-type bovine spongiform encephalopathy (BSE), a transmission study with a Canadian H-type isolate was performed with bovinized transgenic mice (TgBoPrP), which were inoculated intracerebrally with brain homogenate from cattle with H-type BSE. All mice exhibited characteristic neurologic signs, and the subsequent passage showed a shortened incubation period. The distribution of disease-associated prion protein (PrP(Sc)) was determined by immunohistochemistry, Western blot, and paraffin-embedded tissue (PET) blot. Biochemical properties and higher molecular weight of the glycoform pattern were well conserved within mice. Immunolabeled granular PrP(Sc), aggregates, and/or plaque-like deposits were mainly detected in the following brain locations: septal nuclei, subcallosal regions, hypothalamus, paraventricular nucleus of the thalamus, interstitial nucleus of the stria terminalis, and the reticular formation of the midbrain. Weak reactivity was detected by immunohistochemistry and PET blot in the cerebral cortex, most thalamic nuclei, the hippocampus, medulla oblongata, and cerebellum. These findings indicate that the H-type BSE prion has biological and biochemical properties distinct from those of C-type and L-type BSE in TgBoPrP mice, which suggests that TgBoPrP mice constitute a useful animal model to distinguish isolates from BSE-infected cattle.     

Inotropic and lusitropic effects of incremental doses of dobutamine in dogs with right ventricular apical pacing‐induced cardiac dysfunction

This study aimed to assess the effects of incremental doses of dobutamine on diastolic function in healthy and rapid ventricular apical pacing (RVAP)‐induced cardiac dysfunction anesthetized dogs. Inotropic and lusitropic effects of dobutamine (2, 4, 8, and 12 μg kg^?1 min^?1) were assessed through left ventricle (LV) pressure–volume relation and Doppler echocardiography in six female dogs before and after 8 weeks of RVAP. Peak rate of LV pressure fall (?dP/dt_min) improved with doses >4 μg kg^?1 min^?1 in healthy (4,490 ± 970 vs. 3,265 ± 471 mmHg/s, p < 0.05) and >8 μg kg^?1 min^?1 in RVAP dogs (3,385 ± 1,122 vs. 1,864 ± 849 mmHg/s, p < 0.05) while the time constant of relaxation (tau) reduced with doses >4 μg kg^?1 min^?1 in both groups (healthy: 24.0 ± 3.7 vs. 28.2 ± 4.9 ms; RVAP: 32.6 ± 8.5 vs. 37.5 ± 11.4 ms, p < 0.05) comparing with baseline. Indices of relaxation (?dP/dt_min and tau) suggested preserved lusitropic response in contrast with markedly reduced indices of contractility in the RVAP group compared with healthy group at same infusion rates. Doppler echocardiography showed significant reduction of elastic recoil in failing hearts. The results of this study demonstrated maximal positive lusitropic effects of dobutamine at a dose of 8 μg kg^?1 min^?1 in ventricular pacing‐induced cardiac dysfunction without further impairment of ventricular filling.     

An occurrence of Salmonella typhimurium infection in sika deer (Cervus nippon)

Seven sika deer (Cervus nippon) in a herd of 30 deer in a park died. Upon examination of three dead deer, Salmonella Typhimurium was isolated from the organs and intestinal contents. Histopathological examination revealed catarrhal enteritis and focal necroses in the liver. Immunohistochemically, Salmonella antigen of O4 was detected in the enteric lesions. The case was diagnosed as S. Typhimurium infection in the sika deer. Because of the importance of Salmonella in public health, fecal and soil samples were continuously collected from the paddock. However, no Salmonella was isolated from any samples collected after medication of the deer and thorough disinfection of the immediate environment.     

Antibabesial activity of protoberberine alkaloids and 20-hydroxyecdysone from Arcangelisia flava against Babesia gibsoni in culture

Bioassay-guided fractionation of the boiled extract from the stems of Arcangelisia flava led to the isolation of palmatine (1), berberine (2), jatrorrhizine (3), dihydroberberine (4) and 20-hydroxyecdysone (5). The chemical structures of these compounds were elucidated on the basis of their chemical and spectral evidence. The isolated compounds were evaluated for their growth inhibiting effects on Babesia gibsoni in culture for a week. Compounds (1-4) showed significant inhibitions at concentrations from 100 to 1.0 microg/ml, while compound 5 at a concentration of 100 microg/ml, only.     

Plasma melatonin secretion rhythms in cattle under varying seasonal conditions

The purpose of the present study was to investigate the secretion cycles of melatonin (MEL) in cattle over the course of four seasons. Four female Japanese Shorthorn cattle under free‐stall and ad libitum feeding conditions were used, and plasma MEL concentrations were measured over a 48 h period at 1 h intervals. The time‐series data were analyzed by spectral analysis, and the cycle hour was determined. Data indicated that the secretion cycle for MEL was approximately 23.5 h for all four seasons. The area under the curve of MEL from start to end of experiment for 48 h did not differ significantly among the four seasons. However, the duration of high MEL secretion which defined the duration time of the values were more than 10 pg/mL and differed significantly among the four seasons. In conclusion, this study, which was the first to use spectral analysis to evaluate the cyclic rhythm of MEL in cattle, revealed that MEL secretion cycles did not differ among the seasons. These findings are inconsistent with previous study results in that previous reports suggested that the MEL secretion cycle differed under different lighting conditions.     

Listeriosis in a raccoon dog (Nyctereutes procyonoides) associated with canine distemper

A wild raccoon dog (Nyctereutes procyonoides) that manifested severe illness and died was examined. Necropsy revealed severe emaciation, systemic icterus and petechial hemorrhages on the mucous membranes. Histopathologically, necroses were seen in the liver and brain stem associated with meningitis. Eosinophilic intranuclear inclusion bodies were observed in the spleen and intestinal mucosa, and eosinophilic intracytoplasmic inclusion bodies were seen in transitional epithelium in the bladder. Listeria monocytogenes 4b was isolated from the liver, spleen, kidneys and lungs, and the pathogen was also detected in the liver and brain stem immunohistopathologically. The disease was diagnosed as listeriosis associated with canine distemper virus infection in a raccoon dog.     

The real-time stellar evolution of Sakurai's object

After a hot white dwarf ceases its nuclear burning, its helium may briefly and explosively reignite. This causes the star to evolve back into a cool giant, whereupon it experiences renewed mass ejection before reheating. A reignition event of this kind was observed in 1996 in V4334 Sgr (Sakurai's object). Its temperature decrease was 100 times the predicted rate. To understand its unexpectedly fast evolution, we have developed a model in which convective mixing is strongly suppressed under the influence of flash burning. The model predicts equally rapid reheating of the star. Radio emission from freshly ionized matter now shows that this reheating has begun. Such events may be an important source of carbon and carbonaceous dust in the Galaxy.     

Temperature effects on sex differentiation of the reciprocal hybrids of Odontesthes bonariensis and Odontesthes hatcheri (Atherinopsidae)

The pejerrey Odontesthes bonariensis (Valenciennes 1835) and the Patagonian pejerrey Odontesthes hatcheri (Eigenmann 1909) are Atherinopsid species with commercial importance and potential for aquaculture. The hybrids of the two species are viable but their mode of sex determination is unknown. This study examined the gonadal histology and sex ratios of reciprocal hybrids that were reared at 15, 17, 21, 25 or 29 °C during the sex differentiation period. The genetic sex of hybrids from O. hatcheri fathers was inferred from a sex‐linked SNP marker. Both hybrids showed female‐biased sex ratios at the lowest temperature, female‐biased to balanced sex ratios at intermediate temperatures and balanced or male‐biased sex ratios at 29 °C, but unlike in purebred O. bonariensis, the lowest and highest temperatures did not yield monosex populations. The proportion of females in the offspring was affected more by parental genome than by hybrid combination. Female hybrids bearing the O. hatcheri Y chromosome showed temporary arrest of ovarian development that was rescued in adults. These results reveal strong interactions between genotype and temperature for sex determination and differentiation of the hybrids and provide important clues to understand the mechanisms of sex determination in these species.     

Disinfection of Tomato chlorotic dwarf viroid by chemical and biological agents

We investigated the effectiveness of various chemical or biological agents in disinfecting Tomato chlorotic dwarf viroid (TCDVd), which causes extensive damage to tomato crops. Among seven tested chemicals, sodium hypochlorite (NaOCl) was the most effective in disinfecting TCDVd-contaminated scalpels with a 15-s dipping. TCDVd-contaminated scalpels were effectively disinfected by sodium hypochlorite solution at a concentration of 0.5% or more. Sodium hypochlorite at 0.25% and 0.125% could also reduce rates of infection via contaminated scalpels, suggesting that solutions of more than about 0.2% could also be used to suppress infection via TCDVd-contaminated tools. Low-pH sodium hypochlorite solution, which has powerful oxidizing activity, was found to degrade TCDVd dramatically even at low concentrations (below 0.1%). However, the effectiveness of such low-pH solutions in disinfecting TCDVd decreased to a level similar to that of high-pH solutions in the presence of plant tissue residues on tool surfaces, probably because of a reduction in cleaning activity. Although trisodium phosphate (Na₃PO₄) at a concentration of 5% was effective against TCDVd, a 2.5% solution of this chemical was not sufficiently effective against the viroid. Among the biological agents tested, crude sap of pepper plants significantly suppressed TCDVd infection.     

The evaluation of secretion volume and immunoglobulin A and G concentrations in sow colostrum from anterior to posterior teats

Among domestic animals, teat order is only observed in the pig. In order to achieve the healthy growth and weaning of piglets, it is important to elucidate if volume of colostrum secretion and immunoglobulin A (IgA) and IgG concentrations differ among the teats of a sow. Nine sows were used to evaluate the difference in colostrum secretion volume (CSV) and four of these sows were assessed for IgA and IgG concentrations from each teat. Samples were collected five times during 21 h following parturition. Teats were assigned anatomical locations of teat (1 to 7) from anterior to posterior. The CSV of anterior (locations 1 and 2) and middle teats (locations 3–5) was significantly higher than those of posterior teats (locations 6 and 7) throughout the experiment except for 18 h post‐parturition (P < 0.05). The CSV of the teats at location 1 was significantly higher at most collection times than those at locations 6 and 7. A positive correlation of CSV was observed with IgA and IgG concentrations from 12 h and 6 h post‐parturition, respectively (P < 0.05). The results suggest that anterior teats secrete greater volumes of colostrum and that these tend to contain higher IgA and IgG than posteriors teats.