Antioxidation mechanism studies of caffeic acid: identification of antioxidation products of methyl caffeate from lipid oxidation

As a part of a research project on the elucidation of the chain-breaking antioxidation mechanism of natural phenols in food components, caffeic acid, a polyphenolic acid widely distributed in edible plants, was investigated. The identification and time course analysis of the antioxidation reaction products from methyl caffeate were carried out in the ethyl linoleate oxidation system. The antioxidation reaction produced a quinone derivative of methyl caffeate as an antioxidation product during the initial stage, which was identified by (13)C NMR. The quinone, however, was not the final product, and a further reaction occurred to produce several new peroxides. The isolation and structure determination of the peroxides revealed that they had tricyclic structures, which consisted of ethyl linoleate, methyl caffeate, and molecular oxygen. On the basis of the formation pathway of these products, an antioxidation reaction mechanism of methyl caffeate, including the redox reaction of the caffeate and Diels-Alder reaction of the produced peroxides, was proposed.     

Races of <Emphasis Type="Italic">Phytophthora infestans</Emphasis> isolated from potato in Hokkaido,Japan

The virulence of 29 isolates of Phytophthora infestans collected in potato fields in Hokkaido, Japan, in 2013 and 2014, was tested for race identification. Thirteen different races were identified, each of which had five to eight virulence factors. All of the isolates caused a virulent reaction against plants with R1 and R7, and most of the isolates caused a virulent reaction against plants with R3, R4, R10, and R11. On the other hand, no isolate was virulent against plants with R9. These results demonstrate that the current Japanese P. infestans population is more complex than the population in the 1990s from the viewpoint of race.     

Successful treatment by percutaneous transvenous coil embolization in a small-breed dog with intrahepatic portosystemic shunt

A Miniature Dachshund, 3-month-old, 3.1 kg, was diagnosed as an intrahepatic portosystemic shunt (PSS) with the shunting vessel in 6-mm diameter. Percutaneous transvenous coil embolization (PTCE) was performed with a stainless steel coil in 8-mm diameter. Intraoperative portal pressure elevated about 2.5 times after one-stage coil occlusion. Two weeks after the PTCE, serum bile acid levels reduced within the normal range. The portogram showed complete occlusion of the shunting vessel 4 months after the PTCE. Approximately 3 years after the PTCE, the patient has shown no clinical signs. PTCE could be performed more easily and less invasively in a small-breed dog. It is therefore suggested that PTCE is a promising therapeutic technique in canine intrahepatic PSS.     

Effects of first breeding age on the production and reproduction of Holstein heifers up to the third lactation

The effects of early initiation of first service for dairy heifers on their fertility and productivity up to the third lactation were examined under constant raising and management conditions. Eight Holstein heifers in their early breeding regimens and eight Holstein heifers in their late breeding regimens were initiated to be bred at 12 and 15 months of age, respectively, and were first calved at 21.5 and 25.1 months of age, respectively, with bodyweights of 563 and 638 kg after calving, respectively. Early first breeding resulted in a lower bodyweight and a lower body condition score, but it did not affect the fertility or milk production during the first lactation of heifers as cows. The calving intervals of cows to the second and third calving were similar in early and late bred heifers. Although the early bred heifers had a significantly lower fat‐corrected milk yield at the second lactation than that of the late bred heifers, early breeding did not impair the productivity indicated by the mean milk yield per day from birth to the end of the third lactation with a shorter production period.     

VP2 gene of a canine parvovirus isolate from stool of a puppy

VP2 gene of a canine parvovirus (CPV) isolate from the feces of a puppy which was diagnosed to be CPV infection was analysed. The result indicated that this clinical isolate was phylogenetically close to the isolate of wild-type CPV (strain CPV-T37) prevailing in Taiwan rather than isolates from Japan.     

Assessment of left ventricular function using pulsed tissue Doppler imaging in healthy dogs and dogs with spontaneous mitral regurgitation

Pulsed tissue Doppler imaging (pulsed TDI) has been demonstrated to be useful for the estimation of left ventricular (LV) systolic and diastolic functions in various human cardiac diseases. The objectives of this study were to investigate the relationship between pulsed TDI and LV function by using cardiac catheterization in healthy dogs and to evaluate the clinical usefulness of pulsed TDI in dogs with spontaneous mitral regurgitation (MR). The peak early diastolic velocity (E'), peak atrial systolic velocity (A'), and peak systolic velocity (S') were detectable in the velocity profiles of the mitral annulus in all the dogs. In the healthy dogs, S' and E' were correlated with LV peak +dP/dt and -dP/dt, respectively. E' was lower in dogs with MR than in dogs without cardiac diseases. E/E' in the MR dogs with decompensated heart failure was significantly increased in comparison with those with compensated heart failure. The sensitivity and specificity of the E/E' cutoff value of 13.0 for identifying decompensated heart failure were 80% and 83%, respectively. In addition, E/E' was significantly correlated with the ratio of left atrial to aortic diameter. These findings suggest that canine pulsed TDI can be applied clinically for estimation of cardiac function and detection of cardiac decompensation and left atrial volume overload in dogs with MR.     

Homogeneous cell suspension of Malassezia pachydermatis obtained with an ultrasonic homogenizer

It is difficult to produce homogeneous cell suspensions of Malassezia pachydermatis, since yeast cells paste up and form many clumps. However, homogeneous fungal suspensions are required for susceptibility examinations and biochemical analyses. Although several types of trials have been carried out using glass homogenizers and many types of agents to obtain homogeneous fungal suspension. They have not yielded good results. We therefore attempted to use an ultrasonic homogenizer to separate clumps of yeast cells into separate individual cells. We succeeded in this fashion in producing homogeneous cell suspensions of M. pachydermatis. These results indicate that an ultrasonic homogenizer can be used to prepare homogeneous fungal suspensions of M. pachydermatis.     

Differences in vernalisation responses in onion cultivars

Onions normally form bulbs in the first year of growth; however, exposure to low temperatures can induce flowering (vernalisation) before bulbs are produced. Based on the cultivation data of onions grown in Japan, we evaluated and validated a reported model describing the onion vernalisation response. The observed bolting rates of ‘Sapporoki’, which was used in the construction of a previous model, were a good fit to the model, whereas, the bolting rates of one of the overwinter-type cultivars, ‘Momiji No.3?, were lower than the predicted value. The difference between the predicted and observed bolting rates in ‘Momiji No.3? was caused by a larger VD_0.5, the coefficient in vernalisation response models that represents the time point when half of the plants have bolted. Overwinter-type and/or bolting resistant cultivars can have parameters that indicate a further vernalisation requirement for bolting. The parameters in our model can be customised to the cultivar being investigated, and our study suggests the viability of modelling onion bolting by using air temperature.