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Biomedical subjects

S Moriyama

Publications and source records attributed to S Moriyama.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Evaluation of absorbed dose-distribution in the X-ray or gamma-irradiator for blood products].

Irradiation of blood products abrogates the proliferation of lymphocytes present in cellular component, which is currently the only accepted methodology to prevent transfusion-associated graft versus host disease (TA-GVHD). A range of irradiation dose levels between 15 Gy and 50 Gy is being used, but the majority of facilities are employing 15 Gy. It should, however, be recognized that the delivered dose in the instrument canister might differ from the actual dose absorbed by the blood bag. This study have evaluated the actual dose distribution under practical conditions where a container was loaded with blood products or water bags, or filled with distilled water. This approach provides data that the maximum attenuation occurred when the container was completely filled with a blood-compatible material. Thus, an error of approximately 20 percent should be considered in the dose measured in the in-air condition. A dose calibration in an in-air condition may lead to substantial underexposure of the blood products. A dose distribution study using adequately prearranged exposure period verified that the absorbed dose of 15 Gy was attained at any point in the container for both linear accelerator and gamma-irradiator. The maximal difference in the absorbed dose between measured points was 1.5- and 1.6-fold for linear accelerator and gamma-irradiator, respectively. In conclusion, using blood-compatible materials, a careful dose calibration study should be employed in which the absorbed dose of 15 Gy is obtained at the point where the lowest dose could be expected.

Blood Cells↗
PubMed2001

Ethyl esterification of docosahexaenoic acid in an organic solvent-free system with immobilized Candida antarctica lipase.

Ethyl docosahexaenoate (EtDHA) is regarded as a potentially useful pharmaceutical substance on account of its beneficial physiological activities. We attempted the ethyl esterification of docosahexaenoic acid (DHA) in an organic solvent-free system using Candida antarctica lipase, which acts strongly on DHA and ethanol. Esterification of 88% was attained by shaking a mixture of DHA/ethanol (1:1, mol/mol) and 2 wt% immobilized C. antarctica lipase at 30 degrees C for 24 h. However, even in the presence of an excess amount of ethanol, the extent of esterification could not be raised above 90%. To attain a higher level of esterification, a two-step reaction was found to be effective. The first step was performed in a mixture of DHA/ethanol (1:1, mol/mol), and the reaction mixture was then dehydrated. In the second step, the resulting mixture was shaken at 30 degrees C for 24 h with 5 molar equivalents of ethanol against the remaining DHA using 2 wt% immobilized lipase. By means of this two-step procedure, 96% esterification was attained. Repetition of the first and second reactions showed that the immobilized lipase was reusable for at least 50 cycles. In addition, DHA remaining in the second-step reaction mixture was removed by a conventional alkali refining process, giving purified EtDHA with a high yield.

Journal Article↗
PubMed2001

Purification and characterization of an acidophilic xylanase from Aureobasidium pullulans var. melanigenum and sequence analysis of the encoding gene.

An extracellular endo-1,4-beta-xylanase was purified from the culture supernatant of Aureobasidium pullulans var. melanigenum (ATCC 20524) grown on oat-spelt xylan. The purified enzyme showed a single band on SDS-polyacrylamide gel electrophoresis with an apparent M(r) of 24 kDa and had an isoelectric point of 6.7. Xylanase activity was optimal at pH 2.0 and 50 degrees C. The genomic DNA and cDNAs encoding this protein were cloned and sequenced. Southern blot analysis indicated that the xylanase gene (xynI) was present as a single copy in the genome. An open reading frame, consisting of 663 bp, encoded a presumed prepropeptide of 34 amino acids and a mature protein of 187 amino acid. The DNA region encoding the prepeptide was interrupted by a 59-bp intron. A single transcription start point was observed at position -46 (A) from the start codon. The 5'-noncoding region had a putative TATA box at -91 (TATATAA) and two possible CCAAT boxes at -247 (CAAT) and -283 (CCAAT). A cloned xynI cDNA was expressed in Saccharomyces cerevisiae. The deduced amino acid sequence showed 94% identity with that of a previously reported equivalent gene (xynA) encoding a xylanase with an optimal pH of 4.8 from a color variant strain, NRRL Y-2311-1, of A. pullulans. A neighbor-joining tree showed that the Aureobasidium enzymes are closely related to several other family-11 xylanases from black aspergilli and Penicillium purpurogenum.

Journal Article↗
PubMed2001

[A case of advanced hepatocellular carcinoma with portal invasion resected after treatment by continuous intra-arterial chemotherapy with cisplatin and 5-fluorouracil].

A 67-year-old male diagnosed as having inoperable advanced hepatocellular carcinoma with portal invasion was able to undergo resection after continuous intra-arterial chemotherapy with 5-fluorouracil (5-FU) and cisplatin (CDDP). These were continuously administered for 24 hours at doses of 5-FU of 250 mg and CDDP of 5 mg/day, from day 1 to day 5 in a week, repeated 6 times. In additions to the reductions of the levels of AFP and PIVKA-II from 212.6 ng/ml and 16,100 mAU/ml to 11.8 ng/ml and 12 mAU/ml, respectively, the volume of the tumor and the portal invasion were diminished remarkably. As a result, a left extended hepatectomy could be performed. No sign of recurrence was seen during 16 months of follow-up after the operation. Given the above results, continuous intra-arterial chemotherapy with 5-FU and CDDP therapy may be effective for patients with hepatocellular carcinoma.

Aged↗
PubMed2001

[Simultaneous mitral and aortic valvuloplasty using rasping procedure for combined valvular disease: a case report].

We reported a case of successful simultaneous mitral and aortic valvuloplasty using rasping procedure. A 55-year-old woman with combined valvular disease received this operation. Postoperatively, the mitral valve area increased from 1.15 cm2 to 2.03 cm2. Mitral regurgitation improved. Aortic valve pressure gradient decreased from 21 mmHg to 0 mmHg. Aortic regurgitation also improved. Cardiac Index (CI) increased from 1.94 l/min./m2 to 2.59 l/min./m2. Ejection fraction (EF) also increased from 60% to 82%. The postoperative course was uneventful. Excellent postoperative results of this procedure may be expected, not only in single valvular disease but also in combined valvular disease.

Aortic Valve↗
PubMed2001

Functional, metabolic, and histological changes of vascular tissues after warm ischemia.

We examined functional, metabolic, and histological changes in the aortic tissue of rats after the period of warm ischemia ranging from 0 to 24 hours to determine the window of time in which grafts can be optimally viable for harvest. Sixty aortas from Brown Norway rats obtained after warm ischemia were used and changes in contraction, endothelial-dependent or -independent vasodilatation, cell viability, and histology were examined. Maximal contraction induced by norepinephrine and potassium chloride decreased time-dependently after exposure to warm ischemia. The warm ischemic period when 50% of the maximal contractile response of freshly isolated arteries was preserved, ranged from 6 to 8 hours. Maximal endothelium-dependent relaxation induced by acetylcholine decreased along with the time of warm ischemia. Endothelium-independent relaxation induced by sodium nitroprusside and forskolin was unaltered for up to 9 hours. Cell viability gradually decreased, and a significant negative correlation was found between warm ischemic period (T: hours) and cell viability (V: %) (V=101.9-2.35T; r(2)=0.96; p<0.0001). Cell viability was greater than 70% within 12 hours postmortem. Histologically, after 9-hour-warm ischemia irreversible changes were detected. Results suggest that the period of warm ischemia for up to 6 hours would be acceptable for preservation of tissue viability.

Analysis of Variance↗
PubMed2001

Resuscitation and evaluation of non-beating hearts obtained from asphyxiated dogs via autoperfusing heart-lung circuit.

BACKGROUND: The shortage of donor hearts has made use of non-beating hearts as cardiac grafts an attractive possibility for heart transplant candidates. The purpose of this study was to evaluate the utility of leukocyte-depleted hot shot cardioplegia for resuscitation of non-beating hearts obtained from asphyxiated dogs via an autoperfusing heart-lung circuit. METHODS: Mongrel dogs were divided into 3 groups according to the warm ischemia time and the method of reperfusion before starting the autoperfusing heart-lung circuit. Group A (n=4) had 60 minutes of warm ischemia and reperfusion without leukocyte-depleted hot shot, Group B (n=5) had 30 minutes of warm ischemia and reperfusion with leukocyte-depleted hot shot, and Group C (n=7) had 60 minutes of warm ischemia and reperfusion with leukocyte-depleted hot shot. We calculated stroke work via the heart-lung circuit to evaluate cardiac function of the resuscitated hearts. The criteria for "recovery" has been reported elsewhere. Myocardial water content of the resuscitated hearts was also measured and analyzed. No inotropic agents were used. RESULTS: The recovery rates in groups A, B and C were 0%, 80% and 57%, respectively, and the group B rate was significantly higher than the group A rate (p=0.04). Although myocardial water content did not differ between groups B and C, it was significantly lower in recovered hearts than in non-recovered hearts (p=0.04). Significant negative correlation was observed between the maximum stroke work value and myocardial water content in the resuscitated hearts (r=0.668, p=0.03). CONCLUSIONS: The autoperfusing heart-lung circuit is useful for evaluation and maintenance of cardiac function. Our experimental data shows that leukocyte-depleted hot shot plays a great role for resuscitation and recovery of non-beating hearts.

Animals↗
PubMed2000

Activation of human peroxisome proliferator-activated receptor (PPAR) subtypes by pioglitazone.

Pioglitazone, a thiazolidinedione (TZD) derivative, is an antidiabetic agent that improves hyperglycaemia and hyperlipidaemia in obese and diabetic animals via a reduction in hepatic and peripheral insulin resistance. The TZDs including pioglitazone have been identified as high affinity ligands for peroxisome proliferator-activated receptor (PPAR) gamma. The selectivity of pioglitazone for the human PPAR subtypes has not been reported, thus, we investigated the effect of pioglitazone on the human PPAR subtypes. Transient transactivation assay showed that pioglitazone is a selective hPPARgamma1 activator and a weak hPPARalpha activator. Binding assay indicated that the transactivation of hPPARgamma1 or hPPARalpha by pioglitazone is due to direct binding of pioglitazone to each subtype. Furthermore, pioglitazone significantly increased the apoA-I secretion from the human hepatoma cell line HepG2.

Animals↗
PubMed2000

Tau neutrinos favored over sterile neutrinos in atmospheric muon neutrino oscillations.

The previously published atmospheric neutrino data did not distinguish whether muon neutrinos were oscillating into tau neutrinos or sterile neutrinos, as both hypotheses fit the data. Using data recorded in 1100 live days of the Super-Kamiokande detector, we use three complementary data samples to study the difference in zenith angle distribution due to neutral currents and matter effects. We find no evidence favoring sterile neutrinos, and reject the hypothesis at the 99% confidence level. On the other hand, we find that oscillation between muon and tau neutrinos suffices to explain all the results in hand.

Journal Article↗
PubMed2000

Isolation, cDNA cloning, and growth promoting activity of rabbitfish (Siganus guttatus) growth hormone.

We report the isolation, cDNA cloning, and growth promoting activity of rabbitfish (Siganus guttatus; Teleostei; Perciformes; Siganidae) growth hormone (GH). Rabbitfish GH was extracted from pituitary glands under alkaline conditions, fractionated by gel filtration chromatography on Sephadex G-100, and purified by high-performance liquid chromatography. The fractions containing GH were identified by immunoblotting with bonito GH antiserum. Under nonreducing conditions, the molecular weight of rabbitfish GH is about 19 kDa as estimated by SDS-PAGE. The purified hormone was potent in promoting growth in rabbitfish fry. Weekly intraperitoneal injections of the hormone significantly accelerated growth. This was evident 3 weeks after the start of the treatment, and its effect was still significant 2 weeks after the treatment was terminated. Rabbitfish GH cDNA was cloned to determine its nucleotide sequence. Excluding the poly (A) tail, rabbitfish GH cDNA is 860 base pairs (bp) long. It contained untranslated regions of 94 and 175 bp in the 5' and 3' ends, respectively. It has an open reading frame of 588 bp coding for a signal peptide of 18 amino acids and a mature protein of 178 amino acid residues. Rabbitfish GH has 4 cysteine residues. On the amino acid level, rabbitfish GH shows high identity (71-74%) with GHs of other perciforms, such as tuna, sea bass, yellow tail, bonito, and tilapia, and less (47-49%) identity with salmonid and carp GHs.

Amino Acid Sequence↗
PubMed2000

Altered plasma antigen levels of tissue factor pathway inhibitor during open-heart surgery.

Tissue factor pathway inhibitor (TFPI) is a potent inhibitor of the extrinsic pathway of the coagulation cascade that is activated by cardiopulmonary bypass (CPB) during open-heart surgery. In the present study, we investigated whether the plasma TFPI antigen increases during CPB in 12 patients who underwent bypass procedures. The plasma levels of free and total TFPI antigens were measured using an enzyme-linked immunosorbent assay, and heparin concentrations were measured using a chromogenic substrate assay. We found that changes in the total plasma TFPI antigen level were significantly dependent on the level of free TFPI antigen (r = 0.96, P < 0.0001) which increased significantly after heparin injection (P < 0.0001), and increased further during the bypass period (P < 0.005). The increased free TFPI antigen level during CPB correlated with the duration of bypass (r = 0.65, P = 0.02). When heparin was neutralized by protamine, the free TFPI antigen level decreased immediately, but remained higher than the preoperative level (P < 0.005). These results suggest that plasma TFPI antigen levels increase during CPB.

Anticoagulants↗
PubMed2000

Inflammatory pseudotumor of the spleen: report of a case.

A case of a 45-year-old Japanese man with a splenic inflammatory pseudotumor is described. This benign lesion is rarely reported in the world literature. We preoperatively could not rule out the possibility of a malignant neoplasm, due to the fact that the tumor had grown in size after a 2-year observation. However, after performing a splenectomy, a histological examination of the mass revealed an inflammatory process. Inflammatory pseudotumors often pose diagnostic difficulties because the clinical and radiological findings tend to suggest a malignancy. The clinical and pathological features of such previously reported cases are also reviewed.

Diagnosis, Differential↗
PubMed2000

Molecular Cloning of Growth Hormone Complementary DNA in Barfin Flounder (Verasper moseri).

The olive flounder (family Paralichthidae; Paralichthys olivaceus) growth hormone (ofGH) appears to be the most derived among known growth hormones, with the deletion of 14 consecutive amino acids in the carboxy-terminal region. To ascertain if this deletion is common to all flounders, growth hormone complementary DNA of the barfin flounder (bfGH) (family Pleuronectidae; Verasper moseri) has been cloned. It was amplified by polymerase chain reaction using single-strand cDNA from the pituitary gland. Excluding the poly(A) tail, the bfGH cDNA is 919 nucleotides long and contains a 609-bp open reading frame encoding a putative signal peptide of 17 amino acids and a mature protein of 186 amino acids. Northern blot analysis detected 1.0 kb of bfGH messenger RNA in the pituitary gland, which is a reasonable value considering the poly(A) tail. The deduced amino acid sequence of bfGH has 78% identity with the sequence of ofGH. A major difference is the presence of a 14 amino acid segment (140-153) in bfGH, as in other growth hormones, suggesting that this deletion in the olive flounder occurred after the divergence of the Pleuronectoidae.

Journal Article↗
PubMed2000

Effect of epidermal growth factor on lung growth in experimental fetal pulmonary hypoplasia.

The purpose of this study was (1) to compare the expression of epithelial growth factor receptor (EGFR) in the lung tissues of human fetuses with or without pulmonary hypoplasia, and (2) to investigate the effects of EGF on lung growth in experimental pulmonary hypoplasia in rabbits. Firstly, we investigated the expression of EGFR in lung tissues of human fetuses with or without pulmonary hypoplasia by immunohistochemistry. Secondly, the amniotic fluid was shunted into the maternal abdominal cavity in a group of 12 fetal rabbits, another group (n = 12) received EGF injection (5 microg, i.p.) at day 25 of gestation. The third group (n = 12) was only treated with EGF while littermates not operated on served as the control group (n = 12). On day 29 of gestation, fetuses were delivered by Cesarean section and the lungs removed. The body weight and wet lung and liver weights were measured. As a measure of fetal lung growth, we determined the size of lung acini, the number of terminal airspaces, and diameter of alveoli (n = 6, each groups). We also measured the concentration of phosphatidylcholine (PC) and the lecithin/sphingomyelin (L/S) ratio in lung lavage fluid at birth in some fetuses (n = 6, each groups). In human fetuses with pulmonary hypoplasia, there was a significant decrease in radial alveolar count and expression of EGFR compared with fetuses without pulmonary hypoplasia. Amniotic shunt significantly decreased fetal lung/body weight ratio compared with control. Injection of EGF in the shunted group significantly increased lung/body weight ratio to the control level. The concentration of PC and L/S ratio in lung fluid lavage from rabbit fetuses with hypoplastic lungs was significantly higher than the other three groups. Histopathological examination of fetuses with hypoplastic lungs treated with EGF showed no significant change in the size of acini, number of terminal airspaces or the diameter of alveoli compared with the control group. Our results suggested that EGF was associated with lung growth and maturation of human lung and that treatment of rabbit fetuses with hypoplastic lungs with EGF facilitated lung growth and development.

Amniotic Fluid↗
PubMed2000

Unique expression of gonadotropin-I and -II subunit genes in male and female red seabream (Pagrus major) during sexual maturation.

Two distinct gonadotropins (GTHs) have been demonstrated in a number of teleost fishes. Although the physiological roles of GTHs have been extensively studied in salmonids, little is known about their biological functions in nonsalmonid fishes. In this study, to elucidate the role of GTH-I and GTH-II in reproduction, we cloned the alpha-glycoprotein subunit (alphaGSU) and gonadotropin beta subunits (Ibeta and IIbeta) of red seabream using the 5'- and 3'-RACE methods and used these cDNA probes to reveal changes in mRNA levels of each subunit during sexual maturation of both male and female red seabream. The nucleotide sequences of alphaGSU, Ibeta, and IIbeta are 629, 531, and 557 base pairs long, encoding peptides of 117, 120, and 146 amino acids, respectively. The deduced amino acid sequence of each mature subunit showed high homology with those of other teleosts. Northern blot analysis showed that Ibeta mRNA levels of males increase in association with gonadal development, whereas those of females remain low throughout sexual maturation, indicating sexual dimorphism in the expression pattern of Ibeta. In contrast, IIbeta mRNA levels of both sexes are maintained at high levels from the beginning of gametogenesis to spawning season. These results are different than those of salmonids and suggest that GTH-I may have important roles in male, but not female, gametogenesis. GTH-II may be involved in regulation of early and late gametogenesis in both male and female red seabream.

Amino Acid Sequence↗
PubMed2000

Low temperature limits photoperiod control of smolting in atlantic salmon through endocrine mechanisms.

We have examined the interaction of photoperiod and temperature in regulating the parr-smolt transformation and its endocrine control. Atlantic salmon juveniles were reared at a constant temperature of 10 degrees C or ambient temperature (2 degrees C from January to April followed by seasonal increase) under simulated natural day length. At 10 degrees C, an increase in day length [16 h of light and 8 h of darkness (LD 16:8)] in February accelerated increases in gill Na(+)-K(+)-ATPase activity, whereas fish at ambient temperature did not respond to increased day length. Increases in gill Na(+)-K(+)-ATPase activity under both photoperiods occurred later at ambient temperature than at 10 degrees C. Plasma growth hormone (GH), insulin-like growth factor, and thyroxine increased within 7 days of increased day length at 10 degrees C and remained elevated for 5-9 wk; the same photoperiod treatment at 2 degrees C resulted in much smaller increases of shorter duration. Plasma cortisol increased transiently 3 and 5 wk after LD 16:8 at 10 degrees C and ambient temperature, respectively. Plasma thyroxine was consistently higher at ambient temperature than at 10 degrees C. Plasma triiodothyronine was initially higher at 10 degrees C than at ambient temperature, and there was no response to LD 16:8 under either temperature regimen. There was a strong correlation between gill Na(+)-K(+)-ATPase activity and plasma GH; correlations were weaker with other hormones. The results provide evidence that low temperature limits the physiological response to increased day length and that GH, insulin-like growth factor I, cortisol, and thyroid hormones mediate the environmental control of the parr-smolt transformation.

Adaptation, Physiological↗
PubMed2000

Growth regulation by insulin-like growth factor-I in fish.

Insulin-like growth factor-I (IGF-I) is a mitogenic polypeptide that plays an essential role in the regulation of development and somatic growth of vertebrates, mainly by mediating growth hormone actions. It has clearly been established that the structure of IGF-I and its biological function has been highly conserved among vertebrates. In this paper, we review the recent developments in the molecular, biochemical, and physiological properties of IGF-I in fish.

Amino Acid Sequence↗