Occurrence of all-<Emphasis Type="Italic">cis</Emphasis>-5,8,11,14,17,20,23-hexacosaheptaenoic acid (26:7n-3) in roughscale sole <Emphasis Type="Italic">Clidoderma asperrimum</Emphasis> flesh lipids

Fatty acid analysis of roughscale sole Clidoderma asperrimum flesh lipids was carried out by gas chromatography. An unidentified peak appeared in the chromatogram in the elution region of ≥C24 fatty acids. After enrichment by solvent partitioning, reversed-phase thin-layer chromatography (TLC), and argentation TLC, the peak component was subjected to structural analyses. The partially hydrogenated products after reaction with hydrazine hydrate gave seven isomers of cis-hexacosenoic acid (26:1). Gas chromatography-mass spectrometry (GC–MS) analyses of their dimethyl disulfide adducts identified the monounsaturates as 5-, 8-, 11-, 14-, 17-, 20-, and 23-26:1. The peak component was assigned to all-cis-5,8,11,14,17,20,23-hexacosaheptaenoic acid (26:7n-3). GC–MS analyses of the 4,4-dimethyloxazoline derivative and methyl ester confirmed this structure. This fatty acid is a rare, very long-chain polyunsaturated fatty acid (VLCPUFA). The concentrations of the acid found in roughscale sole were 0.69 ± 0.34% (N = 5) of total fatty acids in flesh lipids. Roughscale sole appears to be characterized by the occurrence of 26:7n-3, which is lacking in popular sources of methylene-interrupted VLCPUFA, such as vertebrate retina, spermatozoa, and herring.     

Seasonal variations in and effect of incubation water temperature on vertebral number in naturally spawning chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis>

Seasonal variations and reaction norms for vertebral number (V _N) in response to incubation water temperature were estimated in adult and juvenile naturally spawning chum salmon Oncorhynchus keta. The mean V _N of adults varied according to spawning time; the early-spawning population had higher V _N values than the late-spawning population. Moreover, the mean V _N values in the early-spawning population decreased with seasonal changes, whereas V _N values in the late-spawning population remained stable. Chum salmon embryos in three full-sib families were incubated at five different temperatures until hatching, and the V _N values of the resulting juveniles were analyzed. The V _N reaction norm to incubation water temperature showed a V-shaped curve that was lowest at an intermediate temperature. The mean V _N at the same incubation temperature varied among the three families. These results suggest that V _N values in chum salmon are influenced by genetic components and incubation water temperatures. V _N may be a useful parameter for estimating the environmental conditions during ontogenesis and the genetic background by detecting population changes.     

Piezoelectric behavior of wood under combined compression and vibration stresses II: Effect of the deformation of cross-sectional wall of tracheids on changes in piezoelectric voltage in linear-elastic region

This study investigated and clarified the relation between the piezoelectric voltage and microscopic fracture of hinoki (Chamaecyparis obtura Endl.), in particular the deformation of the cross-sectional wall of the tracheid in linear-elastic regions under combined compression and vibration stresses. The piezoelectric voltage-deformation (P-D) curve consisted of a linear region starting from the origin followed by a convex curved region. The linear region of theP-D curve was only about 60% of that of the load-displacement (L-D) curve. By applying combined stresses to a specimen, the cross-sectional walls of the tracheid were deformed mainly at the radial walls. When a tracheid was regarded approximately as a hexagonal prism, the elastic buckling stress of the radial wall was estimated from scanning electron microscope images and our method based on a modification of the Gibson and Ashby method. As a result, it was estimated that the elastic buckling stress was only about 80% of the stress at the proportional limit of theP-D curve. It is found that there are two consecutive regions before the proportional limit of theP-D curve: One is the region up to the spot where the radial cell wall generates the elastic buckling, and the other is the region starting from the end of the aforementioned region up to the proportional limit of theP-D curve.Part of this paper was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, April 3–5, 1997     

Multiple taste functions of the umami substances in muscle extracts of yellowtail and bastard halibut

Boiled muscle extracts obtained from yellowtail Seriola quinqueradiata and bastard halibut Paralichthys olivaceus were treated with two kinds of purified enzymes (acid phosphatase and glutamate decarboxylase), and the change in contents of nucleotides, related compounds, and free amino acids was examined. The change in taste qualities was also investigated by a taste test. The enzyme treatment resulted in a marked decrease in the contents of such umami substances as inosine 5′-monophosphate (IMP) and glutamic acid (Glu). The taste test revealed that the treatment of these fish muscle extracts with both or either of the enzymes caused a sharp decrease in umami intensity and also an increase in sourness but not a change in pH. The treatment also effected marked decreases in thickness and overall taste intensity. These findings suggest that IMP and Glu function not only to intensify the thickness and overall taste as well as the umami, but also to repress the sourness sensation elicited by the fish muscle extracts.     

Dystrophin-deficient muscular dystrophy in a Toy Poodle with a single base pair insertion in exon 45 of the Duchenne muscular dystrophy gene

A 10-month-old, intact male Toy Poodle was referred for a postural abnormality. Blood biochemical tests revealed a marked increase in plasma creatine phosphokinase (CPK) concentration. The isoenzyme test showed that 99% of serum CPK consisted of CPK-MM. Histopathological evaluation of muscle biopsy samples confirmed scattered degeneration and necrosis of myofibers. Immunohistochemistry for dystrophin showed an absence of staining in muscle cells. Based on these findings, the dog was diagnosed with dystrophin-deficient muscular dystrophy. Whole genome sequencing using genomic DNA extracted from blood revealed a single base pair insertion in exon 45 of the Duchenne muscular dystrophy (DMD) gene. This is the first report on muscular dystrophy in Toy Poodles and identified a novel mutation in the DMD gene.     

Genotypic yield responses of lowland rice in high-altitude cropping systems

Rising global mean temperatures open opportunities in high-altitude production systems for temperature-sensitive crops such as lowland rice. Currently, the cropping window for rice in higher altitudes is still narrow, and thus, genotypes that tolerate a certain degree of chilling are needed to achieve their potential yield. Final yield depends on the interaction between genotype and environmental conditions. Exposing the genotype to a wide range of environments is a way to evaluate its adaptability into an expanding cropping calendar. Over a 2-year period, an experiment was conducted in lowland rice systems in Madagascar at two locations differing in altitude. Twenty genotypes with contrasting levels of tolerance to low temperature were sown monthly in a non-replicated rice garden trial. Plant development was monitored and yield and yield components were determined. Yield stability across the different growing environments was investigated. While crop duration was affected by sowing dates and altitude, yield was mainly determined by sowing date. Panicle number per m² and number of spikelets per panicle were the most limiting factors for yield potential in mid-altitude, while in high altitude, yield was mainly limited by spikelet fertility. Resulting cropping calendar and genotype recommendations are discussed.     

Evaluation by weight change rate of dairy herd condition

The purpose of this study was to clarify whether weight change rate (WCR) is useful in evaluating herd health. Five herds (A, B, C, D, and E) were examined monthly for approximately 1 year to measure both WCR and BCS. WCR was calculated using the following equation: WCR (%) = (body weight of current month-body weight of the preceding month)/body weight of current month x 100. In addition, blood profiles were performed in each herd before and after calving. The incidence of periparturient diseases was higher in Herds A, B, and C compared with Herds D and E. Reproductive performance in Herds A and B was rather poor compared with Herds C, D, and E. There were significantly lower WCRs in Herd A compared with Herd C during the period of day -30 to day 30 after calving. According to the blood profiles, high levels of non-essential fatty acids (NEFA) were observed during the period of day -30 to -1 and high beta-hidroxybutyricacid (BHB) and low levels of glucose were observed at day 30 after calving in Herd A. A marked poor condition in Herd A during the peripaturient period was clearly expressed by low WCR in this experiment. WCR can express body condition of herds and is suggested to be a useful parameter in the determination of herd performance in field experiments.     

Comparison of the insulin reaction of peripheral blood T cells between healthy Holstein dairy cows and JB during the periparturient period

To compare the changes in the insulin reaction of Holstein dairy cows and Japanese Black cows (JB) during the periparturient period, the insulin resistance test in vivo and lymphocytes proliferation with insulin in vitro were performed. Ten healthy Holstein dairy cows (Holstein group) and 10 healthy JB cows (JB group) used in this study were observed on days 60, 40, and 20 before calving and days 7 and 20 after calving. In insulin resistance reaction in vivo and in vitro, a low insulin-stimulated glucose disposal rate and lymphocyte proliferation with insulin were observed in the Holstein group compared with the JB group during the experimental period. An analysis of the lymphocytes cultured with insulin showed that the percentage of CD4+CD45R- T cells in the Holstein group was significantly lower than that of the JB group before day 20. These findings indicate that T cells reaction to insulin in healthy periparturient Holstein cows is lower than that in Japanese Black.     

Separate development of nitric oxide synthase- and vasoactive intestinal polypeptide-immunoreactive nerves arising from the vertebral artery in the rat

Development of nitric oxide synthase (NOS)-and vasoactive intestinal polypeptide (VIP)-immunoreactive (-IR) nerves supplying the basilar and vertebral arteries (BA and VA) was investigated in White Wistar rats, using double immunohistochemistry. NOS-IR and VIP-IR nerves via the anterior circulation (AC), which mostly expressed NO(+)/VIP(+), extended to the BA during the second postnatal week, and usually reached as far as the rostral two third of the BA on PND 20. NOS-IR nerves were completely lack in the cBA and the VA on PND10, and often absent from these arterial regions even at PND 20. Nevertheless, a small number of VIP(+)/NOS(-) nerves were localized in the walls from the caudal BA (cBA) to the VA on PND 5. On PND 20, they frequently met with the descending NOS-IR and VIP-IR nerves via the AC around the lower portion of the middle BA. Fiber bundles containing NOS(+)/VIP(+) axons were first visualized on the caudal VA at PND 30 and observed frequently at PND 80, with a distinct increase in number of NOS-IR and VIP-IR nerves supplying the cBA and the VA. Thus, NOS-IR nerves coming from the VA develop through its own characteristic sequence that lags markedly behind the time of appearance for VIP-IR nerves from the same vascular route and for NOS-IR and VIP-IR nerves via the AC.     

The genetic mechanisms of warfarin resistance in Rattus rattus found in the wild in Japan

Warfarin is commonly used worldwide as a rodenticide. It inhibits blood coagulation by inhibiting vitamin K 2,3-epoxide reductase (VKOR) activity leading to hemorrhage. However, it has been reported that repeated or long-term treatment with warfarin results in resistance emerging in wild rodents. Such resistance may explain why it is difficult to control rodents in many regions in Japan. In this report, we studied mutations in the VKOR gene (including the VKOR complex subunit 1 (VKORC1)), while also analyzing VKOR and clotting factor activity in black rats (Rattus rattus) in order to understand better the mechanism of warfarin resistance in this species.We sequenced the VKORC1 gene from 275 rats living in the wild in Japan. We found several types of novel base substitutions, some of which conferred warfarin resistance.There was no difference in coagulation times between warfarin-sensitive and resistant rats measured under physiological conditions. However, after warfarin administration, no effect was noted in warfarin-resistant rats, although a prolonged coagulation time was noted in warfarin-sensitive rats.We also determined the kinetic differences in hepatic microsomal VKOR-dependent activity between warfarin-resistant and sensitive rats. Warfarin-resistant rats showed 2-3-fold lower V_max/K_m values than did sensitive rats. In addition, we report that resistant rats found in the Tokyo area had a VKOR activity which was poorly inhibited by warfarin.Finally, we conclude that reduced VKOR activity and warfarin resistance in the Japanese black rat might be due to mutations in the VKORC1 gene. However, further study is needed to clarify how such rats can maintain adequate vitamin K-dependent clotting factor levels, while simultaneously exhibiting low VKOR activity and warfarin resistance.