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Biomedical subjects

H Nishida

Publications and source records attributed to H Nishida.

At least 181 records · Page 10Linked to original sources
PubMed1997

Effect of 13-hydroperoxyoctadecadienoic acid on the glucosamine synthetase activity in rabbit gastric mucosa.

The effect of 13-hydroperoxyoctadecadienoic acid (13-HPODE) on the activity of glucosamine synthetase, the rate-limiting enzyme of mucus synthesis, in rabbit gastric corporal mucosa was examined. 13-HPODE inhibited the glucosamine synthetase activity at concentrations ranging from 10 to 100 microM. The effect was concentration-dependent, and the concentration required for 50% inhibition was approximately 20 microM. Experiments utilizing Fe2+ and 13-hydroxyoctadecadienoic acid revealed that the inhibitory effect of 13-HPODE on the glucosamine synthetase activity is not due to the alcohol adduct and hydroxyl radical which are expected to be formed from 13-HPODE, and that the hydroperoxyl functional group is a prerequisite. The fact that tert-butyl hydroperoxide exhibited about 50 times weaker inhibition than 13-HPODE indicates the relative specificity of fatty acyl hydroperoxides in the modulation of the glucosamine synthetase activity. These results suggest that 13-HPODE has the potential to modulate the synthesis of gastric mucus by affecting the glucosamine synthetase activity.

Animals↗
PubMed1996

Biochemical evidence for membrane-bound endoderm-specific alkaline phosphatase in larvae of the ascidian, Halocynthia roretzi.

An endoderm-specific alkaline phosphatase with a molecular mass of 86 kDa has been found in tadpole larvae of the ascidian, Halocynthia roretzi. The histochemical staining of sections of the larvae revealed that the enzyme is a membrane-associated protein. Two distinct bands were detected by zymographic technique on SDS/PAGE of the membrane preparation of the larvae. The two enzymes can be solubilized from the membrane preparation by sodium cholate and separated from each other by Cibacron blue-3GA affinity chromatography. The 86-kDa enzyme is likely to be the endoderm-specific one because the susceptibilities to alkaline phosphatase inhibitors coincide between the 86-kDa enzyme and that found in the endoderm of larvae by histochemical staining. The endoderm-specific alkaline phosphatase was purified and its N-terminal amino acid sequence was found to show little similarity to those of other proteins.

Alkaline Phosphatase↗
PubMed1996

15-Hydroperoxyeicosapentaenoic acid inhibits arachidonic acid metabolism in rabbit platelets more potently than eicosapentaenoic acid.

The effect of 15-hydroperoxy-5,8,11,13,15-eicosapentaenoic acid (15-HPEPE), a hydroperoxy adduct of eicosapentaenoic acid (EPA), on the formation of 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE), thromboxane (TX) B2 and 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) from exogenous arachidonic acid in washed rabbit platelets was examined. 15-HPEPE inhibited 12-HETE, TXB2 and HHT formation at concentrations ranging from 2 to 8 microM. The inhibitory effect of 15-HPEPE was dose-dependent (12-HETE, 16.0-82.9% inhibition; TXB2, 16.7-57.2% inhibition; HHT, 4.6-52.0% inhibition). EPA inhibited the production of these three metabolites, but the inhibitory effect was kept low (20-100 microM: 12-HETE, 8.3-31.1% inhibition; TXB2, 18.9-49.5% inhibition; HHT, 12.5-41.7% inhibition) as compared with 15-HPEPE. Experiments utilizing 15-hydroxy-5,8,11,13,15-eicosapentaenoic acid and hydroxyl radical scavengers (dimethyl sulfoxide and mannitol) revealed that 15-HPEPE exerted its effect in the form of the hydroperoxy adduct. These results suggest that 15-HPEPE has the potential to modulate the activities of the cyclo-oxygenase and 12-lipoxygenase in platelets. This may also be one convincing mechanism for the anti-thrombotic and anti-atherosclerotic actions of EPA.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1996

Electrostatic properties deduced from refined structures of NADH-cytochrome b5 reductase and the other flavin-dependent reductases: pyridine nucleotide-binding and interaction with an electron-transfer partner.

Electrostatic properties on the protein surface were examined on the basis of the crystal structure of NADH-cytochrome b5 reductase refined to a crystallographic R factor of 0.223 at 2.1 A resolution and of the other three flavin-dependent reductases. A structural comparison of NADH-cytochrome b5 reductase with the other flavin-dependent reductases, ferredoxin-NADP+ reductase, phthalate dioxygenase reductase, and nitrate reductase, showed that the alpha/beta structure is the common motif for binding pyridine nucleotide. Although the amino acid residues associated with pyridine nucleotide-binding are not conserved, the electrostatic properties and the location of the pyridine nucleotide-binding pockets of NADH-requiring reductases were similar to each other. The electrostatic potential of the surface near the flavin-protruding side (dimethylbenzene end of the flavin ring) of NADH-cytochrome b5 reductase was positive over a wide area while that of the surface near the heme-binding site of cytochrome b5 was negative. This implied that the flavin-protruding side of NADH-cytochrome b5 reductase is suitable for interacting with its electron-transfer partner, cytochrome b5. This positive potential area is conserved among four flavin-dependent reductases. A comparison of the electron-transfer partners of four flavin-dependent reductases showed that there are significant differences in the distribution of electrostatic potential between inter-molecular and inter-domain electron-transfer reactions.

Binding Sites↗
PubMed1996

Comparison of clinical outcomes of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in renal dialysis patients.

BACKGROUND: The leading cause of death in chronic renal dialysis patients is cardiovascular disease. As the number of dialysis patients increases, we are encountering more patients with severe ischemic heart disease requiring coronary intervention. METHODS: A retrospective analysis was performed of the short- and long-term clinical results in 23 coronary artery bypass grafting patients and 20 coronary angioplasty patients undergoing chronic renal dialysis. RESULTS: Among coronary bypass grafting patients, there were no hospital deaths. The graft patency rate was 100% for arterial grafts. There were four late deaths and four cardiac events. In coronary angioplasty patients, the lesion success rate was 76%. There were no hospital deaths and three major complications. The restenosis rate was 70%. There were two late deaths and 14 cardiac events. The 5-year cardiac event-free rate was 70% in coronary bypass grafting patients, significantly better than 18% in coronary angioplasty patients (p < 0.001). CONCLUSIONS: Coronary artery bypass grafting in chronic renal dialysis patients can be accomplished with a better short- and long-term outcome than coronary angioplasty, through an intensive perioperative dialysis program and extensive use of arterial grafts.

Angioplasty, Balloon, Coronary↗
PubMed1996

Transdiaphragmatic drainage of pericardial effusion with severe pericardial adhesions.

We describe a method to perform successful drainage of pericardial effusion by incising the diaphragm via the peritoneal cavity assisted by transesophageal echocardiography. This transdiaphragmatic approach is a remarkably simple and useful method for pericardial drainage when the conventional transsubxiphoid approach is difficult and dangerous because of intractable adhesions between the heart and the pericardium.

Aged↗
PubMed1996

Surgical treatment of ischaemic valve disease.

Mitral valve regurgitation secondary to ischaemic heart disease carries a significant mortality even after open-heart surgery. In this study, 21 patients with mitral regurgitation associated with ischaemic heart disease were evaluated with respect to valvular pathology. Pathological examination of the mitral valve revealed chorda elongation or rupture in seven patients (group 1), papillary muscle dysfunction in 10 (group 2), and papillary muscle rupture in four (group 3). Significant preoperative characteristics in each group were subacute haemodynamic deterioration in group 1, chronic severe left ventricular failure in group 2, and a high incidence of acute renal failure associated with haemodynamic shock in group 3. Mitral valve plasty was performed in six patients and mitral valve replacement, using the St Jude Medical valve, in 15. Fourteen patients underwent mitral valve surgery combined with coronary artery bypass grafting. Mitral plasty was applied to the patients with low left ventricular function with mean(s.d.) fraction shortening of 19.2(6.2)% compared with 30.2(8.4)% in patients with mitral valve replacement. There were no operative deaths. Of four late deaths, two in group 1 resulted from infection and myocardial infarction, respectively and one in group 2 resulted from arrhythmia. One patient in group 3 died from renal failure. It is suggested that incorporation of these therapeutic concepts may lead to satisfactory results in the surgical treatment of ischaemic mitral regurgitation.

Coronary Artery Bypass↗
PubMed1996

Effects of smaller physical size on complex arterial grafting in coronary artery operations.

BACKGROUND: The trend in coronary artery bypass grafting is for a gradual transition to the more extensive use of arterial grafts. This study was designed to investigate the effects of patient body size on complex arterial grafting in coronary artery bypass procedures. METHODS: Four hundred forty-five patients who underwent coronary artery bypass grafting with two or more distal anastomoses using arterial grafts were divided into two groups according to body surface area: group A (n = 114), 1.60 m2 or less; and group B (n = 331), greater than 1.60 m2. Preoperative patient characteristics and early and long-term results were compared between the groups. RESULTS: The prevalence of female sex (27% in group A versus 0.9% in group B; p < 0.0001) and age (62.7 +/- 8.1 years in group A versus 58.9 +/- 7.0 years in group B; p < 0.001) were significantly different. However, the prevalence of previous myocardial infarction and of left ventricular dysfunction and the extent of coronary artery disease were not significantly different. Three patients (2.6%) in group A and 3 patients (0.9%) in group B died within 30 days of operation (p = 0.18). The 1-month patency rate of arterial grafts was not significantly different (98.7% versus 96.7%; p = 0.16), but that of venous grafts was significantly lower in group A than in group B (88.9% versus 97.7%; p = 0.045). No significant difference was noted in the 3-year actuarial survival rate (93.8% versus 91.6%). CONCLUSIONS: The extensive use of arterial grafts in patients with small body size was associated with excellent long-term results, with no significant increase in operative mortality or morbidity.

Body Constitution↗
PubMed1996

Effects of Fe(2+), Zn(2+), Cu(2+) and Se(4+) on the synthesis and catabolism of prostaglandins in rabbit gastric antral mucosa.

Effects of Fe(2+), Zn(2+), Cu(2+) and Se(4+) on the synthesis and catabolism of prostaglandins (PGs) in rabbit gastric antral mucosa were examined. Fe(2+) inhibited the cyclooxygenase activity in the microsomal fraction. Zn(2+) suppressed the endoperoxide E(2) isomerase activity in the microsomal fraction and the 15-hydroxy PG dehydrogenase (PGDH) activity in the cytosolic fraction. Cu(2+) stimulated the cyclooxygenase activity, inhibited the PGDH activity and possibly induced non-enzymatic reduction of PGG(2) or PGH(2) to PGF(2 alpha) Se(4+) possibly induced the non-enzymatic reduction of PGG(2) or PGH(2) to PGF(2 alpha), as well as Cu(2+). These results suggest that Fe(2+), Zn(2+), Cu(2+) and Se(4+) can be modulators of the gastric antral mucosal PG levels by affecting the PG synthesizing enzymes, PG catabolizing enzyme and/or non-enzymatic reduction of PGG or PGH to PGF.

Animals↗
PubMed1996

Hemifacial degloving approach to tumours in the infratemporal and pterygopalatine fossae: a preliminary report.

A new approach to tumours in the infratemporal or pterygopalatine fossa is presented. Through a midline skin incision, one side of the face from the forehead to the neck is completely degloved. Zygomatic and mandibular osteotomies improve access. All mimic muscles and the facial nerve are included in the elevated flap. This approach provides a widely exposed field from the temporal fossa to the neck without damage to major vessels or nerves other than the supra- and infraorbital nerves. Direct access to tumours in the infratemporal or pterygopalatine fossa is facilitated, thus making tumour resection easier, safer and more reliable. Details of this approach are described.

Craniotomy↗
PubMed1996

Effect of crude fractions of psoralea corylifolia seed extract on bone calcification.

Non-polar crude fractions (Ho-0 and Ho-1) of an acetone extract of Psoralea corylifolia seeds were administrated orally to untreated and experimental rachitic rats. In the biological screening of the fractions, Ho-1, an elution with n-hexane-ethyl acetate by column chromatography over silica gel of the acetone extract, untreated rats showed a significant elevation of the serum inorganic phosphorus and revealed histomorphometrically a significant increase in bone calcification. When Ho-0, an elution with n-hexane, and Ho-1 were administrated to the rachitic rats fed with a vitamin D-free, low-phosphorus diet, they not only increased significantly the concentration of inorganic phosphorus in serum, but also significantly promoted bone calcification. Administration of 30 mg/kg of Ho-1 resulted in a marked decrease of osteoid volume and improvement of hyperosteoidosis in rachitic rats. These results suggested that Ho-0 and Ho-1 are useful as a remedy for bone fracture, osteomalacia, osteoporosis, and related conditions.

Animals↗
PubMed1996

Molecular mechanisms to form leukocyte infiltration patterns distinct between synovial tissue and fluid of rheumatoid arthritis.

There is a striking difference in the leukocyte infiltration pattern between synovial tissue and fluid of rheumatoid arthritis, a monocyte/macrophage-predominant infiltration in the former and a polymorphonuclear leukocyte (PMN)-predominant one in the latter. In extracts of rheumatoid arthritis synovial tissue, there is a strong chemotactic activity to monocytes but a negligible one to PMNs. The monocyte-specific chemotactic factor in the extracts represents dimers (and oligomers) of the S19 ribosomal protein which are cross-linked by a transglutaminase-catalyzed reaction. This oligomer formation may correlate to apoptosis in the lesion. On the other hand, in the synovial fluids there is the co-presence of chemotactic factors effective on PMNs as well as on monocytes and a strong chemotaxis inhibitor specific to monocytes. This inhibitory molecule is C4a which is liberated from complement component 4 in the presence of immune complexes. C4a exhibits its inhibitory activity indirectly by stimulating monocytes to release an autocrine or paracrine inhibitory cytokine to monocyte chemotaxis. These molecular mechanisms seem at least partly to cause the two distinct patterns of leukocyte infiltration in rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1996

Novel peptide ligands for integrin alpha 6 beta 1 selected from a phage display library.

Integrin alpha 6 beta 1 is a major adhesion receptor for the basement membrane, specifically binding to laminin-1. To identify the peptide sequences recognized by alpha 6 beta 1, we screened a 15-mer phage display library by panning with alpha 6 beta 1 purified from human placenta. DNA sequencing of 73 randomly picked phage revealed that three clones were dominantly enriched after repeated panning with alpha 6 beta 1. None of the peptide sequences displayed on these phage showed significant homology to laminin-1. A synthetic peptide modeled after the sequence displayed by one of these phage, designated P3, was found to strongly inhibit the binding of laminin-1 to alpha 6 beta 1. This inhibitory effect of the P3 peptide seems to be specific for alpha 6 beta 1, since it did not affect the binding of fibronectin to integrin alpha 5 beta 1. A synthetic peptide with a scrambled P3 amino acid sequence barely inhibited the binding of laminin-1 to alpha 6 beta 1. When coated on a substratum after conjugation with bovine serum albumin, the P3 peptide was capable of promoting cell spreading in an alpha 6 beta 1-dependent manner, although the peptide with the scrambled sequence showed activity similar to that of a control peptide. These results taken together indicate that the P3 peptide is a novel ligand for integrin alpha 6 beta 1 with potent cell spreading activity.

Amino Acid Sequence↗
PubMed1996

Transcatheter arterial renal and adrenal embolization with iohexol-ethanol solutions. Animal experimental study and clinical application.

RATIONALE AND OBJECTIVES: The authors compared the embolic effect of radiolucent absolute ethanol (AE) with that of a radiopaque iohexol-ethanol (IES) solution for renal ablation in dogs and for the destruction of human aldosteronomas by the technique of transcatheter arterial embolization (TAE) to test whether IES can be an alternative to AE. METHODS: The embolic agents were infused through a balloon catheter into the renal arteries of 17 dogs (9 infused with 0.3 mL/kg AE; 8 infused with IES). The immediate and parenchyma were compared between the two groups. Transcatheter arterial embolization with IES also was performed in three humans with unilateral aldosteronoma. RESULTS: The IES was visualized faintly under fluoroscopy in all dogs. There were no significant differences in embolic effects between the AE and IES. Three patients with aldosteronoma were treated successfully by TAE with IES. CONCLUSIONS: The IES can be used as a "visible ethanol" to improve the safety and ease of ethanol embolization.

Adrenal Cortex Neoplasms↗
PubMed1996

Evaluation of the peripheral circulatory status of the neonate during homeothermal adjustment by plethysmo-time-interval.

The plethysmo-time-interval (PTI) is the time interval between the beginning of the QRS complex on an ECG and the upstroke of the pulse wave on a plethysmogram, as measured by pulse oximetry. In the present study, we investigated homeothermal acclimatization to the extra-uterine environment in human neonates using the Coretemp thermometer and a pulse oximeter. Temperature was measured at three sites: the central deep temperature (CDT) on the upper sternum, the peripheral deep temperature (PDT) on the flat part of the left sole of the foot and the surface temperature (ST) at the side of the abdomen. After delivery, CDT and ST were higher than PDT. The difference between CDT and PDT was large at first, but gradually decreased. PDT, initially in the range of 32.4 +/- 0.28 degrees C, reached a stable value (34.4 +/- 0.41 degrees C) at 2.5 h after delivery. PTI was prolonged in parallel with PDT. The difference between CDT and PDT probably reflected the contraction of skin vessels, particularly the arterioles, which occurs as a body defense mechanism against heat loss. As PTI was prolonged in parallel with PDT, we demonstrated objectively that this catch-up phenomenon of PDT after delivery was affected by the increase in skin blood flow as a result of dilatation of peripheral arterioles. It was concluded that PTI can be used to evaluate the peripheral circulatory status of the neonate, even during homeothermal adjustment after birth, by applying a new principle of pulse oximetry that is widely used in neonatal intensive care units.

Acclimatization↗
PubMed1996

Comparison of two fetal growth curves in screening for high-risk neonates.

The International Statistical Classification of Diseases and Related Health Problems (ICD-10) defines the 10th percentiles on the fetal growth curve as the cutoff point for light- and small-for-gestational-age infants, instead of the mean bodyweight -1.5 standard deviation (SD) on the fetal growth curve, which has been used in Japan since 1983. Data on a 5260 sample of term neonates who were born during the 30-month period between January 1993 and June 1995 were obtained. The clinical usefulness of the 10th percentiles and mean bodyweight -1.5 SD cutoff on the fetal growth curve as screening criteria for high-risk neonates of light- and small-for-gestational-age infants was evaluated. There was a statistically significant higher morbidity rate among the neonates whose birthweight was below mean bodyweight -1.5 SD than for those whose birthweight was below the 10th percentile cut off. But there was no significant difference between the morbidity rate of neonates whose birthweight was between mean bodyweight -1.5 SD and the 10th percentile cutoff and the morbidity rate of neonates whose birthweight was above the 10th percentile cutoff. Therefore, mean bodyweight -1.5 SD on the fetal growth curve is a more effective means of screening for high-risk light- and small-for-gestational-age infants than the 10th percentile cutoff on the fetal growth curve.

Birth Weight↗
PubMed1996

Simple evaluation method of biocompatibility of artificial oxygenator hollow fiber.

We made miniature modules filled with artificial oxygenator hollow fibers and conducted a simple experiment to study the effect of different membrane structures on the blood. Three types of modules were made: one filled with polyolefin, one filled with polypropylene, and a blank module. The 3 modules were connected through 3 fine tubings to one needle so that the same blood that passed through the 3 modules could be analyzed simultaneously. Nonheparinized blood was continuously withdrawn from 6 healthy volunteers using a small pump and passed through the circuit by a single pass (10 ml/min, for 10 min). Platelet count, thrombin-antithrombin complex, and complement-3 were measured in the blood collected at 10 min from the outlet of each module. The results showed significantly better biocompatibility of polyolefin than polypropylene, which is attributable to the dense layer of the blood contact surface of polyolefin fibers. This method is useful in assessing biocompatibility of various hollow fibers in a simple and safe manner.

Analysis of Variance↗