QUANTITATIVE CONTRAST-ENHANCED ULTRASONOGRAPHY OF CANINE SPLEEN

Contrast-enhanced ultrasonography has an important role in the detection of tumors in humans. The second-generation contrast agent Sonazoid has the ability of real-time contrast imaging along with parenchymal imaging. The purposes of this study were to determine the effect and duration of Sonazoid on the changes in gray-scale enhancement of canine spleen and to establish an appropriate protocol for contrast-enhanced ultrasonography of canine spleen. Six healthy beagles were injected with an intravenous bolus of Sonazoid. In the spleen parenchyma, the enhancement was maintained up to 30 min after injection. Moreover, for 5–22 s after injection, gray-scale enhancement of splenic arteries afforded arterial imaging. Perfusion of the kidney may be investigated from 3.6 s to 3.5 min after injection of Sonazoid. These results suggest that Sonazoid is applicable to canine spleen parenchymal imaging and that the optimal time for the parenchymal imaging is 7–30 min after injection. The findings of this quantitative study should prove useful in the evaluation of diffuse or focal splenic and renal diseases in dogs.     

Relationship between parity and mineral status in dairy cows during the periparturient period

Data from 65 cows were collected to clarify the relationship between parity and mineral status in Holstein cows during the periparturient period. Milk fever occurred in a second‐ and a fourth‐lactation cow at parturition. Bodyweight of cows decreased immediately after parturition, and the decreased weights of cows from 1 to 6 days after parturition ranged from 11 to 27 kg. Milk yield of multiparous cows was higher than that of primiparous cows, but Ca and P concentrations in colostrum were not affected by the parity. Plasma glucose of primiparous cows was higher than that of multiparous cows, and plasma nonesterified fatty acids of fourth‐and‐more‐lactation cows at parturition was highest. Plasma Ca concentration of cows at parturition decreased with advancing parity, and plasma inorganic P concentration of third‐and‐more‐lactation cows was lowest at parturition. Plasma parathyroid hormone of fourth‐and‐more‐lactation cows at parturition was highest, but plasma hydroxyproline and alkaline phosphatase was lowest. These results suggest that the large transfer of Ca and P to colostrum is a factor in the development of milk fever in third‐and‐more‐lactation cows.     

Deleterious effects of fungi isolated from paddy soils on seminal root of rice

Soil samples were collected from rice paddies at 22 locations in northeastern Honshu, Japan. In 20 of the samples, seedling growth of rice was improved by soil pasteurization (aerated steaming at 60°C for 30 min), although no typical disease symptoms were observed in the seedlings grown in the untreated soil samples. In most locations, rice seedlings grew better in a potting medium containing root material from plants grown in the pasteurized portion of a soil sample than in a medium with root material from plants grown in the unpasteurized portion of the same sample. The results suggest that microorganisms that restrained rice seedling growth may be common in the soils of rice paddies. Approximately 800 isolates were obtained from seedling roots grown in unpasteurized soils and grouped by cultural and microscopic morphologies. The deleterious effects of 79 isolates from 21 major groups, most of which were soil-dwelling taxa, were examined after direct inoculation of the seminal roots. Isolates of Curvularia sp., Cirrenalia sp., Eppicoccum nigrum, Fusarium graminearum, F. oxysporum, Gliocladium virens, Humicola sp., Penicillium sp., Rhizoctonia oryzae-sativae, Sclerotium hydrophilum, Trichoderma aureoviride, and T. harzianum inhibited root growth, suggesting that deleterious root-infecting fungi were more common in paddy soil than previously thought. These fungi may be involved in the restraint of rice seedling growth.     

Effects of high potassium chloride supplementation on growth rate and renal function in mice

Fifty‐four mice were assigned to a control diet group or a KCl diet group to clarify the effects of KCl supplementation on growth rate, water intake and renal function in mice, and 5% of KCl was supplemented in KCl diets for 1–4 weeks. Bodyweights of KCl supplemented mice were significantly lower than those of control mice, and bodyweights of control and KCl supplemented mice at 28 days after treatment were 45.5 and 41.2 g, respectively. Feed intake was not affected by KCl supplementation, but water intake of KCl supplemented mice was significantly higher than that of control mice. Bone weights of KCl supplemented mice at 2 weeks after treatment were significantly lower than those of control mice. Serum urea nitrogen concentration at 4 weeks and serum K and Cl concentrations at 2 weeks were significantly lower in KCl supplemented mice. Histological alteration using hematoxylin–eosin and Sirius red staining was not found in the kidney of each mouse at 1, 2, and 4 weeks after treatment. These results suggest that high KCl supplementation decreases the rate of bodyweight gain and increases water intake in mice.     

Pigments in green tea leaves (Camellia sinensis) suppress transformation of the aryl hydrocarbon receptor induced by dioxin

Environmental contaminants such as dioxins enter the body mainly through diet and cause various toxicities through transformation of the aryl hydrocarbon receptor (AhR). We previously reported that certain natural flavonoids at the dietary level suppress the AhR transformation induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In this study, we identified lutein and chlorophyll a and b from green tea leaves as the novel antagonists for AhR. These active compounds suppressed AhR transformation dose-dependently with the 50% inhibitory concentration (IC(50)) values against 0.1 nM TCDD-induced AhR transformation at 3.2, 5.0, and 5.9 microM, respectively. (-)-Epigallocatechin gallate, which is the most abundant flavonoid in green tea leaves, also showed stronger suppressive effects than did other major tea components, with the IC(50) value of 1.7 microM. Thus, these pigments of green tea leaves have the potential to protect from dioxin toxicity through the suppression of AhR transformation.     

Mechanism of production of troponin T fragments during postmortem aging of porcine muscle

Troponin T (TnT) is one of the myofibrillar proteins that is easily degraded during postmortem aging of pork. In this study, we determined the N-terminal amino acid sequences of TnT degradation fragments produced during postmortem aging and by m-calpain hydrolysis. The N-terminal amino acid sequences of TnT fragments produced during postmortem aging were EVHEPEEKPRPKLTAP, EKPRPKLTAPKIPEG, and APKIPEGEKVDF. On the other hand, the N-terminal amino acid sequences of TnT fragments produced by the action of m-calpain were APPPPAEV, EVHEPEEK, and APK. These sequences of degradation fragments could be mapped on fast type TnT isoform 2. The peptide bonds of His37-Glu38 and Thr51-Ala52 in fTnT2 were cleaved during postmortem aging as well as by the calpain hydrolysis; therefore, calpain was concluded to have an important role in TnT degradation during postmortem aging. It was also found that the sourness-suppressing peptide APPPPAEVHEVHEEVH (Okumura et al. Biosci. Biotechnol. Biochem. 2004, 68, 1657-1662) derived from TnT degradation could be produced by the action of calpains on Glu21-Ala22 and His37-Glu38 sites.