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Biomedical subjects

T Kageyama

Publications and source records attributed to T Kageyama.

At least 37 records · Page 2Linked to original sources
PubMed2001

Sympathetic predominance in young male white-collar workers with mild to moderate hypertension.

In order to investigate the difference in diurnal variation of autonomic control between young male mild to moderate hypertensive and normotensive white-collar workers, we accessed heart rate variability with ambulatory blood pressure for over 24 hours including work and sleep periods. Both mean systolic and diastolic blood pressures (SBP and DBP) were significantly (p<0.01) higher in hypertensives (HT, n=11) than normotensives (NT, n=11) in all phases, whereas heart rate was not different between them in any phase. Blood pressures during work period (on-duty) were significantly higher than those during non-work period (off-duty) in both NT and HT. High frequency (HF; 0.15-0.40 Hz) power showed a circadian pattern in phase with the sleep-wake cycle. Both HF and low frequency (LF; 0.05-0.15 Hz) powers in HT were significantly lower than that in NT during the sleep period (p<0.05). LF/HF ratio showed a circadian pattern that was almost opposite of the pattern in HF power. Twenty-four-hour average LF/HF in HT was higher than that in NT (p<0.05). Especially during on-duty, LF/HF in HT was significantly higher than in NT (p<0.05). The increase of SBP and LF/HF from off-duty period to on-duty period (deltaSBP and deltaLF/HF) showed significant positive correlation (r=0.67, P<0.05) in HT group, suggesting that the SBP elevation during on-duty in HT may be coupled with sympathetic activation. These results suggest that HT showed significantly reduced parasympathetic control during sleep and an increased sympathetic activity especially during on-duty as compared with NT. Our findings imply that persistence of sympathodominant states together with reduced vagal activity in young mild to moderate hypertensive workers may be related to future cardiovascular disorders.

Adult↗
PubMed2001

[Inhibition of HCFU absorption after resection for gastric cancer--application of hydroxyaluminium gel].

HCFU (carmofur; Mifurol) is an 5-FU analog. The maximum blood concentration of HCFU in HCFU fraction (Cmax) after gastric resection was higher than before resection. Hot sensation and pollakiuria, characteristic side effects of HCFU, are dependent on concentration of HCFU fraction in blood. Therefore, it is considered that the frequency of occurrence of side effects after gastric resection is high. For that reason, we thought that if absorption of HCFU could be reduced, fewer side effects would result. We focused on the fact that drugs which include aluminium gel may decrease absorption in combined drugs, and thought it would be possible to delay absorption in HCFU by using them. We studied the HCFU concentration in the HCFU fraction and 5-FU concentration in blood, respectively, in two cases: 1) single oral administration of HCFU 100 mg and 2) coadministration with hydroxyaluminium gel (ALG) 10 ml in the whole or partial resection of gastric cancers for 8 patients. We found that the concentration of HCFU in the HCFU fraction 2 hours after its administration decreased significantly: 3.24 +/- 1.78 (single administration), 1.37 +/- 0.91 (coadministration with ALG) (p = 0.023). HCFU concentration in the HCFU fraction seemed to decrease for coadministration with ALG in the area under the time-blood concentration curve (AUG) (p = 0.071). The 5-FU concentration did not seem to decrease in either case. From these results, the coadministration of HCFU with ALG seems to be effective for the inhibition of adverse drug reaction after the resection of gastric cancers.

Adult↗
PubMed2001

Evaluation of immunoglobulin G and its subclasses in aplastic anemia.

We selected 31 patients with aplastic anemia to measure their total immunoglobulin (Ig) G and IgG subclasses and compared the results obtained with those obtained in the normal control group (n=461). Patients with aplastic anemia were classified into three subgroups according to severity: mild subgroup (n=14), moderate subgroup (n=12) and severe subgroup (n=5). The decrease in total IgG was recognized in all these three subgroups (p<0.001). Although IgG1 decreased in severe subgroup (p<0.01), it showed no significant difference in mild and moderate subgroups. The decrease in IgG2 and IgG3 was observed in all these three subgroups (p<0.001 and p<0.01, respectively). Although IgG4 decreased in mild subgroup (p<0.05), it showed no significant difference in moderate and severe subgroups. We speculated that the measurement of IgG subclasses was useful in understanding the pathophysiology of humoral immunity in aplastic anemia.

Adult↗
PubMed2001

Cross-sectional survey on risk factors for insomnia in Japanese female hospital nurses working rapidly rotating shift systems.

A cross-sectional survey was carried out for the purpose of examining the association of work stress with insomnia among nurses working rotating shift systems. A self-administered questionnaire on sleep and mental health was distributed to 875 nurses at five hospitals in Japan. Out of the data from 785 (89.7%) respondents, those from 555 women engaged in rapidly and irregularly rotating shift systems as full-time nurses were examined. The prevalence of insomnia (29.2%) was three to four times higher than that in the general population. Among the insomniacs, 23% were current users of medically prescribed hypnotics. Multiple logistic analysis revealed that being 24 or less years old, working three or less night shifts per month, having six or less non-working days per month, receiving less support from colleagues and superiors, and taking care of severely ill patients were independent risk factors for insomnia. The number of hours of a night shift was found not associated with insomnia, taking the above variables into account. These results suggest that at least three factors, i.e., 1) young nurses not adapted to shiftwork, 2) the nurses requiring to remedy sleep deficits on non-working days, and 3) the work stress partly characteristic of nurses, have an adverse influence on their sleep.

Adult↗
PubMed2000

Distribution of the 4F2 light chain, LAT1, in the mouse brain.

LAT1 (the 4F2-light chain 1) is a component of the CD98 surface antigen which participates in multiple functions including amino acid transport, cell survival, cell fusion and integrin activation. We examined the distribution of LAT1 in the mouse brain using immunohistochemistry. LAT1 was expressed on the microvessels, the subfornical organ, the subcommissural organ, ventromedial nucleus of the hypothalamus, subgranular zone of the dentate gyrus, ependymal layer of the lateral ventricles, and the olfactory bulb. LAT1-positive cells incorporated bromodeoxyuridine in the latter three regions where neurogenesis occurs in adult mouse brain, indicating that LAT1 is involved in neuronal cell proliferation, as well as in amino acid transport in these regions.

Amino Acid Transport Systems↗
PubMed2000

In Vitro Evaluation of Pressure Fluctuations with Differing Height of the Infusion Bottle in Phacoemulsification.

Purpose: To investigate the influence of the height of the infusion bottle and vacuum pressure on the development of an occlusion break surge in an in vitro model of the anterior chamber of the eye.Methods: We employed a rigid chamber device to simulate the anterior chamber of the human eye and performed phacoemulsification with a synthetic nucleus. We evaluated amplitude of pressure fluctuations in the chamber. An experimental occlusion break surge was produced at vacuum pressures of 200, 300, and 400 mm Hg. For each vacuum setting, the height of the infusion bottle was preset from 60 to 90 cm at intervals of 5 cm. We performed 6 measurements for each condition.Results: Increase in surge deflection amplitude was proportional to the increase in vacuum pressure (P <.0001). At all vacuum pressures, there was no significant relation between surge deflection amplitude and bottle height. Amplitude of pressure fluctuations in the chamber did not fall below the irrigating pressure if the bottles were kept 70 cm at a vacuum pressure of 200 mm Hg, and 85 cm at a vacuum pressure of 300 mm Hg. At a vacuum pressure of 400 mm Hg, surge deflection amplitude always exceeded irrigating pressure, even if the bottle height of 90 cm was chosen.Conclusion: Increases in vacuum pressure led to increase in amplitude of occlusion break surge. Elevation of the infusion bottle did not decrease the amplitude of occlusion break surge, but increased the pressure in the chamber at the beginning of the surge and prevented the pressure in the chamber from falling below the irrigating pressure.

Journal Article↗
PubMed2000

The 4F2hc/LAT1 complex transports L-DOPA across the blood-brain barrier.

L-DOPA is transported across the blood-brain barrier (BBB) by an amino acid transporter, system L. Recently, it has been demonstrated that system L consists of two subunits, 4F2hc and either LAT1 or LAT2. 4F2hc/LAT1 and 4F2hc/LAT2 show different transport characteristics, while their distribution in the brain has not been determined. To clarify whether 4F2hc/LAT1 participates in L-DOPA transport across the BBB, we first examined the expression of 4F2hc/LAT1 in the mouse brain capillary endothelial cell line, MBEC4, as an in vitro BBB model. Northern hybridization and immunoblotting revealed that both 4F2hc and LAT1 are expressed and form a heterodimer in MBEC4 cells. To confirm whether 4F2hc/LAT1 acts as system L to transport L-DOPA, we characterized L-DOPA uptake into the cells. The uptake process was time-dependent, temperature-sensitive, and Na(+)-independent. Neutral amino acids with bulky side chains and a bicyclic amino acid, 2-aminobicyclo-[2, 2,1]-heptane-2-carboxylic acid (BCH), inhibited L-DOPA uptake into MBEC4 cells to a great extent, while an acidic amino acid, basic amino acids, and glycine had no effect. Other neutral amino acids, such as alanine, asparagine, glutamine, serine, and threonine inhibited L-DOPA uptake by 40-70% at most. These characteristics are more compatible with those of 4F2hc/LAT1, rather than those of 4F2hc/LAT2. Finally, immunohistochemistry with anti-LAT1 antibody demonstrated that LAT1 is predominantly expressed in the microvessels of the central nervous system. This is the first report showing that the 4F2hc/LAT1 complex participates in L-DOPA transport across the BBB.

Amino Acid Transport Systems↗
PubMed2000

Mouse myosin X: molecular architecture and tissue expression as revealed by northern blot and in situ hybridization analyses.

The structure of the coding region of mouse myosin X cDNA was determined. The predicted protein sequence indicated an approximately 240 kDa molecular mass with 2062 amino acids. When aligned with the structure predicted for calf myosin X (GenBank Accession No. U55042), extremely highly conserved pleckstrin homology domains and a myosin tail homology 4 domain were apparent in the tail region, suggesting their importance for myosin X's function. Northern blot analysis revealed the existence of a myosin X mRNA, 8.7 kb in size, in various mouse tissues, while a similar size of human type myosin X mRNA was recognized mainly in the testis. In addition to the adult-type transcripts in mice, a smaller embryo-specific mRNA, 4.8 kb in size, was identified in early to late embryonic stages, suggesting the presence of a shorter myosin X isoform in mouse embryos. In situ hybridization experiments with mouse testis revealed that myosin X mRNA was restricted to Sertoli cells at stages VIII-X of the spermatogenesis cycle, suggesting that myosin X is implicated in the supporting cells during the spermatid morphogenesis.

Amino Acid Sequence↗
PubMed2000

Viremia-associated ana-aki-byo, a new viral disease in color carp Cyprinus carpio in Japan.

A new virus disease that displays dermal ulceration and high mortality has been occurring since 1996 in color carp Cyprinus carpio reared in warm water in Japan. In histological examinations, initial erosive lesions displayed necrosis, hemorrhage and fibrin deposition in the dermal loose connective tissue and were accompanied by the partial destruction of the epidermis. Developed ulcerative lesions involved the lateral musculature with bacterial invasions. In visceral organs, necrotic cells were observed in the hematopoietic tissue, the spleen and the intestinal tissues as well as in cardiac muscle fibers which showed no signs of bacterial invasion. Electron microscopy revealed corona-like virus particles in these necrotic cells. The necrotic cells of the hematopoietic tissue and the spleen were accompanied by the formation of tubular structures and crystalline inclusions. The putative virus was isolated and cultured in epithelioma papillosum cyprini (EPC) cells. Carp experimentally inoculated with the cultured virus showed virus transmission, and the same pathological signs of the disease and mortalities as in natural infections.

Animals↗
PubMed2000

Molecular cloning of neonate/infant-specific pepsinogens from rat stomach mucosa and their expressional change during development.

To clarify the nature of rat neonate/infant-specific pepsinogens, we carried out their purification and molecular cloning. Prochymosin was found to be the major neonatal pepsinogen. The general proteolytic activity of its active form, chymosin, was, however, lower than those of pepsins A and C which are predominant in adult animals. Molecular cloning of rat prochymosin cDNA was achieved along with cDNA for another neonate-specific pepsinogen, pepsinogen F, although determination of pepsinogen F in neonatal gastric mucosa was unsuccessful, presumably due to its lack of proteolytic activity or different proteolytic specificity. Northern blot analysis confirmed that genes for prochymosin and pepsinogen F are expressed only at neonatal/infant stages and the switching of gene expression to that of pepsinogen C occurred at late infant stages. A phylogenetic tree based on nucleotide sequences showed clearly that pepsinogens fall into four major groups, namely prochymosin and pepsinogen F of the neonate/infant and pepsinogens A and C of adult animals. Although, to date, prochymosin and pepsinogen F were believed to be expressed in only a limited number of mammals, the present results suggest that they might be expressed at the neonatal/infant stage in a variety of mammals.

Aging↗
PubMed2000

Jejunal limb obstruction caused by a cholesterol stone 15 years after a total gastrectomy and 20 years after a cholecystectomy: report of a case.

We present herein the rare case of a 74-year-old woman found to have jejunal limb obstruction caused by a cholesterol stone 15 years after a total gastrectomy with Roux-en-Y anastomosis, and 20 years after a cholecystectomy. The patient complained of repeated episodes of upper abdominal distress on three separate occasions over a period of 20 months, and jejunal limb obstruction was diagnosed by abdominal computed tomography scanning and (99m)Tc scintigraphy. Surgery revealed a stone incarcerated in the jejunal limb, where the anastomosis had become slightly stenotic. The removed stone was 3.5 cm in diameter and was subsequently demonstrated to be a cholesterol stone by chemical analysis. This report is thought to be the first to describe jejunal limb obstruction caused by a gallstone incarcerated in the jejunal limb after a total gastrectomy in a patient with a history of cholecystectomy.

Acute Disease↗
PubMed2000

Removing silicone oil droplets from the posterior surface of silicone intraocular lenses.

A 67-year-old woman had droplets of silicone oil adhering to her silicone intraocular lens (IOL) resulting from a previous silicone oil tamponade. A lens hook and intraocular irrigation were used in conjunction by inserting an infusion cannula to remove the droplets. This restored clarity of the visual axis, improved visual acuity, and eliminated the need for IOL replacement. The technique is simple and less invasive than IOL exchange and may become the preferred way to remove silicone droplets from an IOL.

Aged↗
PubMed2000

New world monkey pepsinogens A and C, and prochymosins. Purification, characterization of enzymatic properties, cDNA cloning, and molecular evolution.

Pepsinogens A and C, and prochymosin were purified from four species of adult New World monkeys, namely, common marmoset (Callithrix jacchus), cotton-top tamarin (Saguinus oedipus), squirrel monkey (Saimiri sciureus), and capuchin monkey (Cebus apella). The occurrence of prochymosin was quite unique since this zymogen is known to be neonate-specific and, in primates, it has been thought that the prochymosin gene is not functional. No multiple form has been detected for any type of pepsinogen except that two pepsinogen-A isozymogens were identified in capuchin monkey. Pepsins A and C, and chymosin hydrolyzed hemoglobin optimally at pH 2-2.5 with maximal activities of about 20, 30, and 15 units/mg protein. Pepsins A were inhibited in the presence of an equimolar amount of pepstatin, and chymosins and pepsins C needed 5- and 100-fold molar excesses of pepstatin for complete inhibition, respectively. Hydrolysis of insulin B chain occurred first at the Leu15-Tyr16 bond in the case of pepsins A and chymosins, and at either the Leu15-Tyr16 or Tyr16-Leu17 bond in the case of pepsins C. The presence of different types of pepsins might be advantageous to New World monkeys for the efficient digestion of a variety of foods. Molecular cloning of cDNAs for three types of pepsinogens from common marmoset was achieved. A phylogenetic tree of pepsinogens based on the nucleotide sequence showed that common marmoset diverged from the ancestral primate about 40 million years ago.

Amino Acid Sequence↗
PubMed2000

Multiplicities and some enzymatic characteristics of ape pepsinogens and pepsins.

Pepsinogen levels in ape stomachs were comparable to those in macaques and significantly higher than those in the stomachs of other mammals, including carnivores and ruminants. The occurrence of multiple forms of pepsinogens was remarkable. Nine, sixteen, eight, and fourteen pepsinogens were purified or partially purified from the gastric mucosa of a gibbon, orang-utan, gorilla, and chimpanzee, respectively. Most of these were type-A pepsinogens, and only one type-C pepsinogen was identified in each ape. The two types could be readily distinguished by staining for proteolytic activity on polyacrylamide gel electrophoresis (PAGE) in the presence/absence of pepstatin. Type-A pepsinogens were further divided into two subtypes. One subtype, constituting a major group of pepsinogens in apes, exhibited high hemoglobin-digestive activity. The other subtype was specified by a relatively high content of Lys and low hemoglobin-digestive activity. It is likely that pepsinogen-A genes have been duplicated several times as hominoids, including humans, evolved in the primate lineage. The presence of multiple pepsinogens in apes might be advantageous in the efficient digestion of a wide variety of foods.

Amino Acids↗