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Biomedical subjects

S Moriyama

Publications and source records attributed to S Moriyama.

At least 91 records · Page 5Linked to original sources
PubMed1998

Insulin-like growth factor-I and environmental modulation of growth during smoltification of spring chinook salmon (Oncorhynchus tshawystscha).

The relations among rearing environment, fish size, insulin-like growth factor-I, and smoltification were examined in yearling spring chinook salmon (Oncorhynchus tshawytscha). Juvenile chinook salmon were size-graded into small and large categories. Half of the fish in each group were reared at an increased temperature and feeding rate beginning in mid-February, resulting in four distinct treatment groups: large warm-water (LW), large cool-water (LC), small warm-water (SW), and small cool-water (SC). Increased temperature and feeding rate resulted in overall higher growth rates for the LW and SW groups. Temporal increases in insulin-like growth factor-I (IGF-I) were found in all groups through the spring. Plasma IGF-I levels were significantly higher in warm-water groups than in cool-water groups from late March through May. Size itself appeared to have little relation to plasma IGF-I levels. Simple regression showed a significant relation between plasma IGF-I and growth (P < 0. 001, R2 = 0.50). No differences were found between treatment groups in other physiological parameters assessed (plasma thyroxine, gill Na+-K+-ATPase, liver glycogen, body lipid).

Animals↗
PubMed1998

[Clinical benefits of normothermic cardiopulmonary bypass on postoperative systemic metabolism].

To evaluate the influence of body temperature during cardiopulmonary bypass (CPB) on postoperative systemic metabolism, 32 patients undergoing elective cardiac surgery were randomly assigned to either hypothermia (n = 16) or normothermia (n = 16). Serial hemodynamic parameters and blood samples were obtained after surgery. CPB and operation times were significantly shorter and the platelet reduction ratio during CPB [ = (platelets before CPB-platelets after CPB)/platelets before CPB] was significantly lower in normothermic patients than in hypothermic patients. The platelet reduction ratio was dependent on the minimum rectal temperature during CPB, the operation time, and the CPB time. In the early postoperative period, hypothermic patients had abnormally high systemic vascular resistance and a reduced cardiac index compared with the normothermic patients. There were no differences between 2 groups in postoperative hepatic and renal functions, changes in oxygen consumption, arterial-venous PCO2 or arterial-venous pH gradient. This study suggested a beneficial influence of normothermic CPB on postoperative hemodynamics. Normothermic CPB was not associated with adverse effects on postoperative metabolic recovery.

Aged↗
PubMed1998

Origin of regenerated epithelium in cryopreserved tracheal allotransplantation.

BACKGROUND: Our previous study showed that a cryopreserved tracheal allograft could be transplanted using omentopexy without immunosuppression. The present study investigated, by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, whether the regenerated epithelia were of recipient origin or donor origin in a cryopreserved tracheal allotransplantation model. METHODS: Twenty-nine mongrel dogs were classified by preoperative peripheral blood PCR-RFLP analysis. The cryopreserved tracheal allografts were implanted into recipient animals that showed a different phenotype from donor animals. A small specimen of epithelia excised from the allograft of animals postmortem was analyzed with the modified PCR-RFLP method. RESULTS: The animals were separated into 16 phenotypes by preoperative PCR-RFLP results, and cryopreserved tracheal allografts transplanted into 8 animals. PCR-RFLP analysis of graft epithelia at 10 days after transplantation showed the donor blood phenotype and analysis of graft epithelia taken from the animals that survived more than 20 days after operation showed the recipient blood and epithelial phenotype. CONCLUSIONS: The donor epithelia in the grafts were no longer present within about 20 days after transplantation. The recipient epithelia migrated gradually from the anastomotic site, and the regenerated epithelia that are of recipient origin covered the allograft within about 50 days after transplantation.

Anastomosis, Surgical↗
PubMed1998

Evolution of insulin-like growth factor-I (IGF-I) action: in vitro characterization of vertebrate IGF-I proteins.

While there is considerable structural evidence that IGFs share a long evolutionary history, less is known about the conservation of IGF action. These studies have primarily been hampered by the small amounts of purified IGFs that have been available for testing. More recently, however, we have adopted recombinant strategies to produce milligram quantities of IGFs for biological studies. Thus we have been able to compare the properties of rat, kangaroo, chicken, salmon and barramundi IGF-I, proteins that differ from human IGF-I by 3, 6, 8, 14 and 16 amino acids respectively. While we have found that the IGF-I proteins exhibit similar biological activities and type-I IGF receptor binding affinities, regardless of whether mammalian, avian or piscine cell lines are used, there was a trend suggesting that the fish proteins at least, were most effective in studies using homologous systems. Thus, salmon IGF-I was not as potent as human IGF-I in bioassays in mammalian cells, but was as effective as human IGF-I in piscine cells. As expected, the IGF-I proteins competed poorly for binding to type-2 receptors present on ovine placental membranes. Interestingly however, the two fish IGF-I proteins exhibited greater affinity for this receptor than the other IGF-I proteins, hence reminiscent of the results previously found with recombinant hagfish IGF. Despite these small differences, these results taken together indicate that the IGF-I proteins appear to have been remarkably conserved in both structure and in vitro action during vertebrate radiation.

Amino Acid Sequence↗
PubMed1998

Isolation and characterization of insulin in Russian sturgeon (Acipenser guldenstaedti).

Insulin was isolated from the pancreas of Chondrostean fish, the Russian sturgeon, Acipenser guldenstaedti, by acid-ethanol extraction followed by ion-exchange and reverse-phase high-performance liquid chromatographies. The amino acid sequence determined by automated Edman degradation is as follows: A-chain (21-amino-acid peptide), H-Gly-Ile-Val-Glu-Gln-Cys-Cys-His-Ser-Pro-Cys-Ser-Leu-Tyr-Asp-Leu-Glu-As n-Tyr-Cys-Asn-OH; and B-chain (31-amino-acid peptide), H-Ala-Ala-Asn-Gln-His-Leu-Cys-Gly-Ser-His-Leu-Val-Glu-Ala-Leu-Tyr-Leu-Va l-Cys-Gly-Glu-Arg-Gly-Phe-Phe-Tyr-Thr-Pro-Asn-Lys-Val-OH. The sturgeon insulin appears to be identical with one of two forms of paddlefish insulin and differs from the other form by a single substitution in the A-chain, Asp15: His15. The amino acid sequence of sturgeon insulin is more similar to the amino acid sequence of mammalian insulins than of other fish insulins. Sturgeon insulin showed parallel but weaker displacement than porcine insulin and pink salmon insulin in their respective radioimmunoassays and was less potent than porcine insulin in displacing radiolabeled porcine insulin bound to partially purified rat liver plasma membranes.

Amino Acid Sequence↗
PubMed1998

Macrofollicular variant of papillary thyroid carcinoma.

A rare case of a macrofollicular variant of papillary thyroid carcinoma occurring in an 18-year-old male is described. The extirpated tumor, 5.5 x 5.5 x 3.5 cm in size, was well demarcated and multinodular, and histopathologically showed a predominantly macrofollicular structure reminiscent of adenomatous goiter or macrofollicular adenoma. In the tumor tissue, however, there were several small foci of microfollicular or papillary structure with the nuclei characteristic of papillary carcinoma. Parts of the macrofollicular areas also showed similar nuclear characteristics with a transition to microfollicular or papillary areas. Incomplete capsular invasion and minimal vascular invasion were also present. Additional resected specimens contained small metastatic nodules in the residual left lobe and lymph nodes. Immunohistochemistry showed a small number of p53-positive tumor cells in the microfollicular or papillary areas. It is suggested that this tumor is a well-differentiated variant which should be distinguished from benign thyroid lesions, although there have been some cases of metastases which appear related to capsular and/or vascular invasion.

Adolescent↗
PubMed1998

Adaptive multimode lubrication in natural synovial joints and artificial joints.

To examine the lubrication mechanisms in both natural synovial joints and artificial joints with artificial cartilages, pendulum tests of pig shoulder joints and simulator tests of sliding pairs of a stainless steel spherical component and natural articular cartilage or artificial cartilage have been conducted. Firstly, it was shown in pendulum tests of pig shoulder joints that both concentration of hyaluronic acid or viscosity and adsorbed film formation of proteins and phospholipids exerted a significant effect on frictional behaviour in swinging motion immediately after a loading of 100 N. Under a high load of 1 kN, low friction was observed under wide-ranging viscosity conditions, since a high load similar to body weight probably enhanced the squeeze film effect due to improved congruity. Next, frictional behaviour of sliding pairs in knee joint models, consisting of a stainless steel spherical surface and either specimens of pig tibial cartilage or polyvinylalcohol (PVA) hydrogel, was examined during walking in simulator tests. In these tests, the influences of lubricant viscosity and addition of protein on frictional behaviour were evaluated. For both compliant materials, the appropriate addition of gamma-globulin to sodium hyaluronate (HA) solution maintained low friction and protected rubbing surfaces under thin film conditions. These phenomena are discussed from the viewpoint of adaptive multimode lubrication.

Animals↗
PubMed1998

Prediction of transient lubricating film thickness in knee prostheses with compliant layers.

The transient lubricating film thickness in knee prostheses using compliant layers has been predicted under simulated walking conditions based upon the elastohydrodynamic lubrication theory. Qualitative agreement has been found between the present theoretical predictions and the experimental measurements using an electric resistance technique reported earlier. It has been shown that the contact geometry plays an important role in the generation of fluid film lubrication in knee prostheses using compliant layers. The maximum lubricating film thickness is predicted for the maximized contact area of a transverse conjunction where the semi-minor contact radius lies in the direction of entraining. The additional advantage of the transverse contact conjunction is that the possibility of lubricant starvation due to small stroke length can be minimized. All these factors, together with the kinematic requirements in the natural knee joint, should be taken into consideration when designing artificial knee joint replacements.

Biocompatible Materials↗
PubMed1998

Effect of rabeprazole (E3810), a novel proton pump inhibitor, on intragastric pH in healthy volunteers.

In this study, we examined the effect of rabeprazole (E3810), a novel proton pump inhibitor, on gastric acidity under physiological conditions in healthy volunteers using 24-hour intragastric pH monitoring. Twenty-four-hour intragastric pH monitoring was performed three times to seven subjects randomly assigned in a cross over fashion to one of the following groups; without drug administration (basal), and with 10 mg or 20 mg of rabeprazole for four days. The median pH for 24 hours was 2.15 in the basal study, while the corresponding median pH were 5.05 and 5.90 after treatment with 10 mg and 20 mg of rabeprazole, respectively. Significant differences in the median pH were observed between the basal study and that after administration of the 10 mg and 20 mg doses of rabeprazole. The cumulative percentage of pH readings above the threshold pH 4 value, was 34.1% in the basal study, and 72.6% and 78.3% after treatment with 10 mg and 20 mg doses of rabeprazole, respectively. This result indicates that the efficacy of rabeprazole allows for substantial control of gastric acidity with once-daily dosing, and that both the 10 mg and 20 mg doses result in potent inhibition of gastric acid secretion.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

[Correlation between 13C-urea breath test and gastric histological findings in Helicobacter pylori positive patients].

13C-urea breath test (UBT), available for diagnosis of Helicobacter pylori (HP) in the stomach, measures the 13CO in the breath in which 13C urea is resolved in the stomach by urease derived from HP. Accordingly UBT is useful for a test of HP infection. This study is aimed at clarifying the relationship between the UBT and gastric histological findings. For this study we selected 63 patients with HP infection who showed both positive UBT and positive histological diagnosis. Briefly in the UBT procedure, the patients were given 13C-urea (100 mg dissolved 100 ml water) in a fasting state and kept in the left decubitus position for 5 minutes, and then the patients were asked to expire into testing bags before and 20 minutes after administration of the urea. Biopsy specimens were taken endscopically from the gastric antrum and the body. The specimens of all patients showed positive CLO test. HP organisms, inflammation, activity, and atrophy of the gastric specimens, were expressed in score from 0 to 3 according to the Update Sydney system. The UBT values were high correlated with the increase of HP organisms. The UBT was 11.8, 26.3, and 37/1000 in the groups with the scores of 0.1, and 2 in the number of HP organisms from the gastric body, respectively. The UBT was 19.2, 22.2, 36.1, 26.7/1000 in the groups with scores of 0, 1, 2, and 3 for the specimens from the antrum, respectively. The results show that there is a positive correlation between the UBT values and HP organisms. As a result, the UBT correlated with the activity score. Grade of gastric mucosal atrophy was expressed histologically in scores of 0,1,2, and 3. The UBT was 29.4, 19.1, 17.5, and 9.3/1000 in the groups with scores 0,1,2, and 3 in the grades of gastric atrophy from the gastric body, respectively. There was a negative correlation between the UBT values and the grade of gastric atrophy. We conclude that the UBT values which indicate the number of HP organisms can be used not only for diagnosis of HP infection but also the quantitative index of HP load.

Adult↗
PubMed1998

Life-threatening reperfusion injury in skeletal muscle: a simple technique to control critical hyperkalemia.

A 55-year-old male suffering from acute abdominal aortic occlusion due to iatrogenic aortic dissection was urgently admitted to hospital. An axillo-bifemoral bypass was constructed 6 hours from the onset of dissection. Before and after revascularization, blood samples were repeatedly obtained from a systemic artery and femoral vein. The arterial potassium concentration gradually increased, reaching 7.3 mM/L. Oliguria and arrhythmias occurred, and the left lower limb became rigid 3 hours after reperfusion. The femoral artery and vein were clamped and within 30 minutes, the arterial potassium concentration fell to 4.8 mM/L. The urine output increased. The left lower limb was amputated, and the patient survived. Immediately following revascularization, hyperkalemia may occur. Clamping of the afferent and efferent vessels is recommended as a simple and practical technique to quickly control life-threatening hyperkalemia.

Amputation, Surgical↗
PubMed1997

Ovarian receptors for insulin and insulin-like growth factor I (IGF-I) and effects of IGF-I on steroid production by isolated follicular layers of the preovulatory coho salmon ovarian follicle.

In this study, receptors for insulin and insulin-like growth factor I (IGF-I) in isolated theca-interstitial layers and granulosa cells of the coho salmon preovulatory ovary were characterized, and the effects of IGF-I on ovarian steroidogenesis were examined. Specific receptors for insulin and IGF-I were found in granulosa and theca-interstitial layers. In both follicular layers, IGF-I receptors were greater in number and higher in affinity than insulin receptors. The effects of IGF-I on in vitro production of testosterone (T) and 17 alpha-hydroxyprogesterone (17OH-P) by theca-interstitial layers and of 17 beta-estradiol (E2) and 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17,20 beta-P) by granulosa cell layers were evaluated during the preovulatory period. Both human and salmon recombinant IGF-I inhibited the basal and GTH II-stimulated T and 17OH-P production by theca-interstitial layers throughout the preovulatory period. In contrast, IGF-I stimulated the production of both E2 and 17,20 beta-P by granulosa cell layers prior to germinal vesicle breakdown (GVBD) but only stimulated the production of 17,20 beta-P by granulosa cell layers after GVBD. The inhibitory effects of IGF-I on steroid production by the theca-interstitial layer and the opposite stimulatory effects on steroid production by the granulosa cell layer, coupled by the presence of specific IGF-I receptors in both follicular layers, suggest that IGF-I may play a role in the regulation of steroidogenesis in the preovulatory coho salmon ovary.

Animals↗
PubMed1997

Salmon thyroid-stimulating hormone: isolation, characterization, and development of a radioimmunoassay.

Coho salmon (Oncorhynchus kisutch) thyroid-stimulating hormone (TSH) was isolated by ethanol extraction of pituitary glands from mature coho salmon. Extraction was followed by gel-filtration chromatography on Sephadex G-100 superfine, anion-exchange chromatography on a Whatman DE-52 column, and finally by reverse-phase high-performance liquid chromatography. Fractions were monitored for TSH content by a homologous in vivo bioassay and by immunoblots using anti-human TSH beta-subunit antisera. In vivo treatment of coho salmon parr with coho salmon TSH caused a dose-dependent increase in plasma thyroxine level similar to that induced by bovine TSH. The N-terminal sequence (25 residues) of the salmon TSH beta subunit has 56% sequence identity to that of human TSH beta subunit and is identical to the deduced amino acid sequence of trout TSH beta subunit. The N-terminal sequence (25 residues) of the salmon TSH alpha subunit is identical to gonadotropin alpha-II subunit. Molecular sizes of the alpha and beta subunits are 18,000 and 24,000 daltons, respectively, as estimated by SDS-PAGE. Antiserum generated against salmon TSH, which was preadsorbed with alpha subunit using an alpha-subunit affinity column, detected only salmon TSH beta subunit by immunoblot and specifically stained thyrotropin-producing cells of the pituitary gland. A homologous radioimmunoassay (RIA) was developed using purified salmon TSH standard, iodinated TSH beta subunit, and antiserum generated against salmon TSH. Cross-reactivities of GTH I, GTH II, GTH I beta and GTH II beta subunits, alpha subunit, growth hormone, prolactin, and somatolactin were less than 1%. Displacement curves for serial dilutions of plasma and pituitary extracts of various salmonid species, as well as coho salmon pituitary cell culture medium, were parallel to the coho salmon TSH standards. In contrast, plasma of hypophysectomized juvenile coho salmon and pituitary extracts of Pacific tomcod (Microgadus proximus) did not displace bound radiolabeled salmon TSH. Finally, in vivo injection of juvenile coho salmon with triiodothyronine decreased plasma TSH levels, whereas the goitrogen, methimazole, increased plasma TSH levels. Injection of gonadotropin-releasing hormone agonist did not alter plasma TSH. These data suggest that the RIA is specific for TSH and confirm a negative-feedback relationship between the thyroid hormones and TSH.

Amino Acid Sequence↗
PubMed1997

Sequence-based association analysis of HLA class I and II alleles in Japanese supports conservation of common haplotypes.

Alleles of HLA-A, B, C, DRB1, DQB1, and DPB1 loci were fully determined in 117 healthy Japanese. A*2402, A*3303, A*1101, A*0201, B*4403, B*5201, Cw*0102, Cw*1403, Cw*0304, Cw*0702, Cw*0801, and Cw*1202 showed frequencies of over 10%. Multi-locus haplotype frequencies were estimated by the maximum likelihood method. Strength of association between C and B loci was comparable with that between DRB1 and DQB1 loci. Alleles unidentified by a serological method and having very similar nucleotide sequences (A2: A*0201, A*0206, A*0207, B61: B*4002, B*4006) were carried by different haplotypes. Several frequent five-locus haplotypes were identified including A*3303-Cw*1403-B*4403-DRB1(*)1302-DQB1(*)0604, and A*2402-Cw*1202-B*5201-DRB1(*)1502-DQB1(*)0601. These sequence-based haplotypes corresponded to serology-based common haplotypes which have already been described in Japanese. These findings indicate that common HLA haplotypes consist of particular sets of HLA alleles and that these haplotypes have been conserved through recent human evolution.

Alleles↗
PubMed1997

A dynamic state of a closed ecosystem and its significance to the generation of the Earth's environment.

The Earth forms a living-system composed of large materially closed ecosystems (CES). We are performing various experiments to study comparable living-systems, especially smaller samples we call "microcosmic type CES". CES have an ability to persist despite perturbation. We show experimental results of the behavior of CES mainly during the transition form a semi-open state to an entirely closed one. We report phenomena on CES instability which may be inherent in them. We suggest that CES possess some properties that may help elucidate the nature of the Earth as a living system. Climatic change on the Earth, such as oceanic anoxia and its consequences, may have been due to disturbances as modeled in a CES.

Earth, Planet↗
PubMed1997

[Arterial-venous carbon dioxide tension difference after hypothermic cardiopulmonary bypass].

Arterial-venous carbon dioxide tension difference (Pv-aCO2) is known to become high after severe hemorrhage shock and resuscitation. We hypothesized that Pv-aCO2 might be high after cardiac surgery because of the oxygen debt occurred during hypothermic cardiopulmonary bypass (CPB). Blood pressure, cardiac index, hemoglobin, the arterial and mixed venous blood gases were repeatedly measured every 6 hours for 24 hours following cardiac surgery in 60 adult patients who underwent hypothermic CPB. Immediately after the surgery, Pv-aCO2 was extremely high, then gradually decreased to within normal ranges 12 hours later (8.0 +/- 2.9 mmHg vs 5.9 +/- 3.1 mmHg. p < 0.01). Factors which significantly correlated to Pv-aCO2 were cardiac index, oxygen delivery, minimum rectal temperature and duration of CPB. Oxygen debt during hypothermic CPB might cause significantly high Pv-aDO2. At least 12 hours were necessary to recover from anaerobic status to physiological condition.

Adult↗