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Biomedical subjects

N Yamagishi

Publications and source records attributed to N Yamagishi.

At least 19 recordsLinked to original sources
PubMed2006

Dose response to vaginal administration of 1,25-dihydroxyvitamin D3 to cows.

It was previously reported that intravaginal (IVAG) administration of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) might be protective against bovine hypocalcaemia. In the present study, various doses of exogenous 1,25(OH)(2)D(3) were administered IVAG to ovariectomised cows, and the subsequent changes in the biochemical parameters of the blood were measured to assess the characteristics of vaginal absorption. Five cows received 1,25(OH)(2)D(3) IVAG at a dose of 0.125, 0.25, 0.5, or 1.0microg/kg of body weight (BW) or intravenously at a dose of 1.0microg/kg BW. Dosing was at intervals of at least two weeks in a 5x5 Latin square design. Vaginally administered 1,25(OH)(2)D(3) was absorbed in a dose-dependent manner. There was no correlation between the IVAG dose of 1,25(OH)(2)D(3) and subsequent changes in plasma calcium concentrations. The bioavailability of 1,25(OH)(2)D(3) administered IVAG at 1.0microg/kg BW was approximately 93%.

Absorption↗
PubMed2005

The expression of genes for transepithelial calcium-transporting proteins in the bovine duodenum.

Intestinal epithelial cells contain calcium-binding proteins and Ca2+-transporting adenosine triphosphatase (Ca2+-ATPase), which play important roles in intestinal Ca transport. However, the factors that affect the expression of these transepithelial Ca-transporting proteins in dairy cattle are unknown. In this study, a semi-quantitative reverse transcription polymerase chain reaction was used to determine the expression of the mRNAs for intestinal Ca-binding protein calbindin-D9k (CaBP9k), two isoforms of plasma membrane Ca2+-ATPase (PMCA1 and PMCA4), and vitamin D receptor (VDR) in duodenal tissue samples from 20 non-lactating, non-pregnant Holstein dairy cattle (0.4-135.9 months old). The correlations between the expressions of transepithelial Ca-transporting proteins, the ages of the cattle, and the presence of several plasma components were evaluated. The duodenal CaBP9k mRNA content had a significant negative correlation with age and positive correlations with plasma inorganic phosphorus (iP) and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) concentrations. The PMCA1 mRNA content was negatively correlated with the plasma Ca concentration. The duodenal PMCA4 mRNA content was correlated negatively with the plasma iP. The VDR mRNA content had a positive correlation with the plasma magnesium concentration.

Animals↗
PubMed2005

Distribution of new methylene blue injected into the caudal epidural space in cattle.

To investigate the distribution of solutions injected into the first intercoccygeal epidural space, 24 adult, standing cattle were randomly assigned to 5-, 10- and 20-mL groups and injected with 0.12% new methylene blue (NMB) in 0.9% saline. Ten heifers received 1 mL NMB solution/100 kg of body weight. There was a significant correlation between the injected volume and the number of cranially stained spinal segments in three adult cattle groups (correlation coefficient R2=0.46; P<0.0001). In three cattle, NMB solution did not distribute more than one spinal segment cranially from the injection site due either to fibrosis of the epidural tissue or to inadvertent intravenous administration into the epidural vein. The study showed that the larger the volume of solution injected, the greater the spread with increased individual variation. The results could form the basis for determining the volume of injection required and for evaluating the pharmacokinetics of anaesthetics used in caudal epidural anaesthesia.

Anesthesia, Epidural↗
PubMed2004

Technical note: Vaginal absorption of 1,25(OH)2D3 in cattle.

Although exogenous 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] administered via intravenous, intramuscular, and oral routes has been tested for efficacy in preventing parturient hypocalcemia in dairy cows, there are few reports concerning intravaginal administration. For this study, 1,25(OH)2D3 was administered via the bovine vaginal lumen, and subsequent changes in blood chemistry, including levels of 1,25(OH)2D3 and several minerals, were measured to confirm vaginal absorption. Each of 5 heifers received a single intravaginal dose of 1 microg of 1,25(OH)2D3/kg body weight; a single control heifer received the ethanol carrier alone. In heifers receiving 1,25(OH)2D3, the plasma 1,25(OH)2D3 levels increased markedly from baseline (88.3 +/- 20.3 pg/mL) within 2 h and reached a peak at 6 h after treatment (1967.4 +/- 1139.6 pg/mL). Plasma Ca levels increased from baseline (10.4 +/- 0.4 mg/dL) to a peak of 11.96 +/- 0.7 mg/dL at 24 h. The levels of inorganic phosphate in plasma increased over time from 7.3 +/- 0.5 to 8.1 +/- 0.8 mg/dL by 6 h and were maintained at a plateau level (9.1 +/- 0.7 to 8.6 +/- 0.6 mg/dL) from 24 to 96 h after treatment. Plasma magnesium decreased from a baseline level of 2.1 +/- 0.1 mg/dL to a plateau level of 1.8 +/- 0.1 mg/dL, which was sustained from 24 to 48 h after treatment. The present study provides evidence of the absorption of exogenous 1,25(OH)2D3 from the bovine vaginal wall, as shown by the marked elevation of plasma 1,25(OH)2D3 levels by 2 h after administration, and indicates the possible utility of intravaginal administration of 1,25(OH)2D3 for prophylaxis of hypocalcemia.

Absorption↗
PubMed2003

Characterization of the small subgenomic RNA of Soybean dwarf virus.

We have characterized a small subgenomic RNA of Japanese strains of Soybean dwarf virus (SbDV). Northern blot analyses of SbDV-infected plants showed that the small RNA contained the 3' terminal sequence of the genome and was detected in four typical Japanese SbDV strains, YS, YP, DS and DP. In the case of SbDV-DS, the RNA was 220 nucleotides in length and was transcribed from the 3' terminal region of the genome. This RNA appeared at a similar time to genomic RNA and a large sgRNA, and thereafter persisted in the infected plant. Since no conserved open reading frame (ORF) among the strains was postulated in the 3' terminal region, the small subgenomic RNA may have some regulatory roles in SbDV infections.

Luteovirus↗
PubMed2003

Antagonistic effects of intravenous or epidural atipamezole on xylazine-induced dorsolumbar epidural analgesia in cattle.

This study was performed to clarify the antagonistic actions of intravenous or epidural atipamezole on the sedative and analgesic effects of xylazine administered between the epidural fat and dura mater through the first interlumbar space in cattle. Cattle received 5 mL of a solution containing 0.05 mg x kg(-1) xylazine in 0.9% saline. Thirty minutes later, 5 mL of 0.9% saline was administered through the same needle (treatment 1) (XSE). In treatments 2 (XAE) and 3 (XAV), 5 mL of a solution containing 0.025 mg x kg(-1) atipamezole in 0.9% saline was administered epidurally or intravenously, respectively. Sedation and analgesia were similar in all three treatment groups and could be reversed by atipamezole given by either route. In the XAV treatment, the flank area relapsed into analgesia 25+/-5.8 min following reversal of the analgesic effect, and was maintained for 112.5+/-63.8 min. The present study confirmed that the sedative and analgesic effects of xylazine are completely reversed by atipamezole and can be influenced by the epidural fat in cattle. Furthermore, it seems probable that analgesia following epidural administration of xylazine is mediated by alpha(2)-adrenergic receptors, not by a local anaesthetic effect.

Adipose Tissue↗
PubMed2003

Comparative histology of the laminar bone between young calves and foals.

Laminar bone or primary plexiform tissue, not Haversian bone, shows an alternative concentric pattern of laminar-bone units or plates around the bone marrow periphery of long bones, although the laminar bone is gradually replaced by osteons during the growth period. One laminar-bone unit is constructed with a hypercalcified line in the center, woven bone on both sides of the line, and lamellar bone with laminated appositional lines. Such a laminar bone showing a homogeneous calcification has been reported in young calves and some young large animals, but it has not been reported in foals although a previous report proposed that the bone structure was distinguishable from plexiform tissue. In this study, we compared young calves with foals by backscattered electron imaging mainly of transverse ground sections of mid-diaphysis. Foals had many hypercalcified lines arranged concentrically around the bone marrow periphery, which were similar to those of young calves. However, rows of cylindrical osteon-like structures with Haversian canal-like canals running along the long-bone axis were arranged between the concentric hypercalcified lines. Each Haversian canal-like structure was enclosed with laminated appositional rings of lamellar bone deposited on the woven bone. In the developing period, the bone units containing the concentric hypercalcified lines were basically equal to the laminar-bone units. The osteon-like structures or 'pseudo-osteons' were gradually replaced by 'true osteons' during the growth period. The blood vessels in the Haversian canal-like canals of foals ran along the long-bone axis, whereas the blood vessels in the concentrically prolonged bone cavities of young calves ran transversely to obliquely against the long-bone axis. Thus, the long-bone cortex of foals showing an alternative concentric pattern of a row of the osteon-like structures arranged between the hypercalcified lines will be histologically classified into a variety of laminar bone caused by the different arrangement of blood vessels. Such a laminar bone may have a biomechanical structure against physical stress, especially the modified laminar bone of foals with osteon-like structures, when compared with the typical concentric laminar bone of young calves and also Haversian bone possessing variously calcified numerous osteons caused by bone remodeling.

Animals↗
PubMed2002

Expression of calbindin-D9k messenger ribonucleic acid in the gastrointestinal tract of dairy cattle.

The calcium demands of pregnancy and lactation are known to up-regulate expression of Calbindin-D9k (CaBP-9k) mRNA in the intestines. The gastrointestinal CaBP-9k mRNA expressions has not been studied in dairy cows, which are bound to experience several pregnancies and lactation stages. In this study, the CaBP-9k mRNA expression were examined in the gastrointestinal tract of Holstein dairy cattle by Northern blot analysis. Detectable expression of CaBP-9k mRNA was localized in the proximal portion of the small intestines. These expressions were higher at the most proximal region of the duodenum and gradually decreased distally. The duodenal CaBP-9k mRNA was detected in all dairy cattle from 0.4 to 83.4 months old, but was not detectable in foetuses. There were no significant correlations between the age and the levels of CaBP-9k mRNA expression or between the plasma 1,25-(OH)2D3 concentrations and the levels of CaBP-9k mRNA expression.

Age Factors↗
PubMed2002

Clinical and colonoscopic investigation of skipped periappendiceal lesions in ulcerative colitis.

BACKGROUND: Ulcerative colitis (UC) is typically a continuous and diffuse inflammation extending proximally from the rectum. However, skipped lesion in the appendiceal region has been reported recently. Although appendectomy has been shown to reduce the risk of UC, the clinical significance of skipped periappendiceal lesion remains unclear. The present study examined the relationship between the continuous distal lesion of UC and the skipped periappendiceal lesion by observing colonoscopic changes in both lesions. METHODS: Among 279 patients with UC who underwent total colonoscopy from January 1994 to December 2000, 54 patients (19.4%) had skipped periappendiceal lesions. Serial colonoscopic examinations were performed in 35 of the 54 patients to determine the activities in the distal UC lesion and skipped periappendiceal lesion during the course of disease. RESULTS: Patients with skipped periappendiceal lesions were younger and had a longer history of UC than those without them, but no differences in sex ratio and treatment modality were observed between the two groups. In 28 of 35 patients (80%), the activity in the distal lesion correlated well with that in the skipped periappendiceal lesion. Both lesions were improved in 17 patients, unchanged in 5 patients and worsened in 6 patients. Linear regression analysis showed a significant correlation between the changes in colonoscopic activity index in the two lesions. CONCLUSION: A close association is found between disease activity in the skipped periappendiceal lesion and that in the distal lesion of UC.

Adult↗
PubMed2001

Role of hsp105 in protection against stress-induced apoptosis in neuronal PC12 cells.

hsp105alpha is a stress protein characteristically highly expressed in the brain compared with other tissues in mammals. Here, to examine whether hsp105alpha plays a pivotal role in the nervous system, we tested the capability of hsp105alpha to protect against apoptosis in rat neuronal PC12 cells. Various stress treatments such as serum deprivation, heat shock, hydrogen peroxide, etoposide, and actinomycin D induced apoptosis in PC12 cells with characteristic shrinking of nuclei and chromatin. However, PC12 cells that constitutively overexpressed mouse hsp105alpha exhibited a strong protective effect against apoptosis induced by these stress treatments. Cleavage of poly(ADP-ribose) polymerase induced in PC12 cells by these treatments was inhibited in the constitutively overexpressed hsp105alpha cells. Furthermore, c-Jun N-terminal kinase (JNK) was activated in the cells treated with heat shock but not other treatments, and the heat-induced JNK activation was inhibited by the constitutive expression of hsp105alpha.Thus, hsp105alpha prevents not only heat-induced apoptosis by inhibiting JNK activation, but also prevents the apoptosis induced by other stressors through different pathways, and may play important roles in neuronal protection.

Animals↗
PubMed2001

Characteristic changes of stress protein expression in streptozotocin-induced diabetic rats.

Stress proteins (heat shock proteins, HSP) play essential roles in folding, assembly and translocation of polypeptides and also in maintenance of the integrity of polypeptides as molecular chaperones. Since long-lasting hyperglycemia causes modification of cellular proteins, it is possible that expression of molecular chaperones may be altered during the course of diabetes. Here, we examined the cellular levels of stress proteins such as HSP105, HSP90 and HSC70/HSP70 in various tissues of streptozotocin-induced diabetic rats. In comparison to controls, the levels of HSC70 were markedly decreased in the liver but not in the brain, adrenal gland and pancreas of diabetic rats. The levels of HSP105 and HSP90 were not significantly changed in these tissues of diabetic rats. Furthermore, the induction of HSP70 as well as HSC70 by hyperthermia was significantly reduced in the liver and adrenal gland of diabetic rats. These results suggested that the expression and induction of HSC70/HSP70 may be altered during the course of diabetic disease and may result in impairment of the cytoprotective ability of diabetic rats.

Animals↗
PubMed2001

Evidence for dissociation between the perceptual and visuomotor systems in humans.

When a visual stimulus is continuously moved behind a small stationary window, the window appears displaced in the direction of motion of the stimulus. In this study we showed that the magnitude of this illusion is dependent on (i) whether a perceptual or visuomotor task is used for judging the location of the window (ii) the directional signature of the stimulus, and (iii) whether or not there is a significant delay between the end of the visual presentation and the initiation of the localization measure. Our stimulus was a drifting sinusoidal grating windowed in space by a stationary, two-dimensional, Gaussian envelope (sigma=1 cycle of sinusoid). Localization measures were made following either a short (200 ms) or long (4.2 s) post-stimulus delay. The visuomotor localization error was up to three times greater than the perceptual error for a short delay. However, the visuomotor and perceptual localization measures were similar for a long delay. Our results provide evidence in support of the hypothesis that separate cortical pathways exist for visual perception and visually guided action and that delayed actions rely on stored perceptual information.

Humans↗
PubMed2001

The effects of vagotomy on the abomasum in calves: radiography and protein gene product 9.5 immunohistochemistry.

Abomasal disorders of calves with total vagotomy, operated on at 1 week old, were investigated with radiography and protein gene product (PGP) 9.5 immunohistochemistry. Radiographic findings indicated abomasal atony with dilatation in all calves 2 weeks after vagotomy, while 4 weeks after vagotomy abomasal dilatation was detected in 2 calves and another 2 calves showed dilatation and impaction. The densities of PGP 9.5-immunoreactive nerves in the tunica muscularis decreased significantly in the corpus region of the greater curvature 2 weeks after vagotomy and in the pyloric region of the lesser curvature 4 weeks after vagotomy, and it was at its lowest 4 weeks after vagotomy in all regions examined. In conclusion, abomasal dilatation and/or impaction in vagotomized calves confirmed by radiography were related with a decreased frequency of nerves in the tunica muscularis of the abomasum.

Abomasum↗