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Biomedical subjects

Y Okuda

Publications and source records attributed to Y Okuda.

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

Relative serum amyloid A (SAA) values: the influence of SAA1 genotypes and corticosteroid treatment in Japanese patients with rheumatoid arthritis.

OBJECTIVES: (1) To determine whether serum concentration of serum amyloid A (SAA) protein is influenced by the SAA1 allele in Japanese patients with rheumatoid arthritis (RA) as previously shown in a healthy control group; and (2) to analyse what factors, based on such an allelic bias, influence the relative SAA values of those patients. METHODS: SAA and C reactive protein (CRP) concentrations together with SAA1 genotypes were determined in 316 Japanese patients with RA. The relative SAA values were evaluated as an SAA/CRP ratio. RESULTS: Comparison of the three SAA1 homozygote groups showed that the SAA/CRP ratio was highest in the 1.5/1.5 group (mean 9.0, p<0.01 v the other two homozygote groups) followed by the 1.3/1.3 group (mean 7.2, NS v the 1.1/1.1 group) and the 1.1/1.1 group (mean 4.0). The SAA/CRP ratio was significantly higher in patients receiving corticosteroids regardless of the presence of allele 1.5. No clear differences in the ratio between patients with or without amyloidosis were found. CONCLUSION: The SAA1.5 allele and corticosteroid treatment had a positive influence on SAA concentrations in serum. These findings are important when evaluating SAA concentration in inflammatory diseases and when considering the cause or treatment of amyloidosis.

Adolescent↗
PubMed2001

Enhancement of endothelial nitric oxide production by chenodeoxycholic acids in patients with hepatobiliary diseases.

The purpose of this study was to clarify whether physiological concentrations of bile acids could affect endothelial nitric oxide production. We investigated the relationships between clinical concentrations of individual bile acids observed in patients with hepatobiliary diseases and endothelial nitric oxide production induced by each bile acid. Fifteen serum bile acids were measured using high-performance liquid chromatography combined with enzymatic fluorometry in 8 patients with liver cirrhosis, obstructive jaundice, and 8 healthy subjects. The effects of individual bile acids on nitric oxide production were examined in human umbilical endothelial cells by measuring the concentration of NO2- in the cultured medium. NO release in the blood was also determined by measuring the NO2-/NO3- concentration in these patients. In patients with hepatobiliary diseases, the plasma concentrations of chenodeoxycholic acid, ursodeoxycholic acid and cholic acid (free acid, taurine and glycine conjugates) were markedly elevated. Incubation of cells with chenodeoxycholic acid and deoxycholic acid (free acid, taurine and glycine conjugates) enhanced NO2- production in a concentration-dependent manner, while cholic acid (free and its conjugates) did not. The effects of individual bile acids on nitric oxide production were additive. Patients with liver cirrhosis and obstructive jaundice had higher plasma levels of NO2-/NO3- levels than the control subjects. These results suggest that increased plasma concentrations of chenodeoxycholic acid (free, taurine and glycine conjugates) in patients with hepatobiliary diseases may induce endothelial nitric oxide production. Thus, nitric oxide production induced by bile acids may be involved in the pathogenesis of circulatory abnormalities in patients with liver diseases.

Aged↗
PubMed2001

[A case of ventricular tachycardia immediately after electroconvulsive therapy in a schinzophrenic patient].

A 33 year-old man weighting, 93 kg with schizophrenia underwent repeated electroconvulsive therapy (ECT) under general anesthesia with thiamylal 200 mg and suxamethonium 80 mg. On his fourth ECT, he developed ventricular tachycardia (VT) immediately after the treatment under general anesthesia with the same agents. The duration of VT was approximately 30 s. The VT returned to sinus rhythm without any special treatment. We speculate that light anesthesia with a small amount of thiopental associated with release of serum potassium caused by suxamethonium induced increased release of catecholamine by ECT to cause VT. After that incident, the patient underwent ECT six times under general anesthesia with thiamylal 250 mg and vecuronium 8 mg, in combination with preventive injection of magnesium sulfate 20 g without any cardiovascular complications. We conclude that the anesthetic management of patients undergoing ECT under general anesthesia should be paid a careful attention for cardiovascular instability, even if they do not have any heart diseases.

Adult↗
PubMed2001

[Anesthetic experience of emergency coronary artery bypass graft operation in a patient with cardioamyloidosis].

A 76-year-old woman with acute myocardial infarction underwent an emergency coronary artery bypass graft operation. She developed cardiac failure and sick sinus syndrome before the surgery because she was with cardioamyloidosis. Therefore, intra-aortic balloon pumping and the pacemaker were used to maintain the hemodynamics prior to the operation. Anesthesia was induced with midazolam 5 mg, morphine 30 mg and pancuronium 5 mg, and maintained with 0.3-0.5% isoflurane in 50% nitrous oxide and 50% oxygen. Morphine 10 mg was also injected during the surgery, and the total dose of morphine 40 mg was administered. The pacemaker at 80 bpm was inserted and mexiletine 0.5 mg.kg-1.h-1 was given to prevent ventricular arrhythmias at weaning from cardio-pulmonary bypass. The surgical operation was successfully performed and the postoperative course was uneventful. A combination of light inhalation anesthesia with narcotics may be a choice for anesthetic management of patients with cardioamyloidosis as this method has less influence on hemodynamics.

Aged↗
PubMed2001

[Anesthetic management of two patients with essential thrombocythemia].

We report different methods of anesthetic management in two patients with essential thrombocythemia. Case 1 is a 69-year-old male scheduled for cholecystectomy. His blood platelet counts were maintained between 10 to 40 x 10(4).microliters-1 after myelosuppression therapy. His preoperative blood tests were within normal limits. Since he had no signs of hemorrhage or thrombus preoperatively, an epidural catheter was inserted for intraoperative analgesia and postoperative pain relief. Anesthesia was induced with propofol and fentanyl, and maintained with N2O-O2-sevoflurane. Mepivacaine 1% was injected through the epidural catheter for intraoperative analgesia and buprenorphine was injected through the catheter for postoperative pain relief. His perioperative course was uneventful. Case 2 is an 88-year-old female scheduled for emergency enterectomy. She had had recurrent bouts of thrombosis. Her blood platelet counts were 89.1 x 10(4).microliters-1. Since her preoperative management of thrombocythemia had been poor, epidural anesthesia was not performed. Anesthesia was induced with propofol, and maintained with N2O-O2-sevoflurane. Her perioperative course was uneventful. We conclude that spinal or epidural anesthesia is not contraindicated when preoperative platelet counts and aggregation test are within normal limits in a patient with essential thrombocythemia.

Aged↗
PubMed2001

[Anesthetic management of a patient with congenital antithrombin III Deficiency using temporal inferior vena cava filter].

We described the perioperative management of a patient with congenital antithrombin III deficiency using temporal inferior vena cava filter. A 30-year-old man with congenital antithrombin III deficiency was scheduled for artificial head replacement of the hip joint under general anesthesia. He was diagnosed as having congenital antithrombin III deficiency when he had had an episode of venous thrombosis after artificial head replacement of the right hip joint. He had been taking warfarin as an anticoagulant, and it was discontinued three days before surgery. To prevent perioperative thrombus formation, the plasma AT III activity was maintained above 80% before, during and after surgery using AT III concentrates. We also placed the temporal inferior vena cava filter. There was no serious thrombosis or embolism perioperatively. The use of the filter during the perioperative period helped to avoid development of serious thrombosis and embolism.

Adult↗
PubMed2001

Effects of fibronectin bonding on healing of high porosity expanded polytetrafluoroethylene grafts in pigs.

BACKGROUND: We developed a new fibronectin bonding to expanded polytetrafluoroethylene (ePTFE) and previously reported that, in a dog carotid implant model, fibronectin bonding improves graft healing in high porosity ePTFE grafts. The purpose of this study was to further investigate the effect of the fibronectin bonding on graft healing in a pig carotid implant model. METHODS: Fifteen pigs received a high porosity ePTFE graft treated with the fibronectin bonding (fibronectin-bonded graft) on one side and an untreated graft (non-bonded graft) on the contralateral side. The grafts were explanted at intervals of 3 and 6 weeks and subjected to histological studies. RESULTS: At 3 weeks, the neointima of fibronectin-bonded grafts was better organized than that of non-bonded grafts. At 6 weeks, the morphologic features of the neointima were the same in fibronectin-bonded and non-bonded grafts. The neointima was completely organized. CONCLUSIONS: Together with the previous results with the dog model, fibronectin bonding could be expected to improve healing of the high porosity ePTFE grafts in humans.

Animals↗
PubMed2001

[Effects of low reactive level laser, linear polarized light and Xenon-ray irradiation on the stellate ganglion in dogs].

The aim of this study was to clarify the influence of low reactive level laser, linear polarized light and Xenon-ray irradiation on stellate ganglion activity in dogs. Under general anesthesia, the right stellate ganglion was exposed by thoracotomy. After stabilization of the hemodynamic parameters, the following baseline measurements were taken: mean arterial pressure (MAP), heart rate (HR), and right brachial artery blood flow (BABF). Experiment 1: The stellate ganglion was directly irradiated for 10 min with low reactive level laser, linear polarized light or Xenon-ray. The hemodynamic parameters were measured for 60 min after each irradiation. Immediately after the irradiation study, stellate ganglion blockade (SGB) with 0.5% mepivacaine 1.0 ml was performed. Experiment 2: After confirming a decrease in BABF by direct electrical stimulation on the stellate ganglion, the stellate ganglion was directly irradiated with low reactive level laser, linear polarized light or Xenon-ray. The hemodynamic parameters were measured for 60 min after each irradiation. Immediately after the irradiation study with 0.5% mepivacaine 1.0 ml was performed. The hemodynamic parameters were also measured for 60 min after SGB. The changes in variables were not statistically significant after each irradiation in the experiment 1 and 2. After SGB, a significant decrease in HR and a significant increase in BABF occurred in the experiment 1 and 2. In conclusion, this study demonstrated that irradiation with low reactive level laser, linear polarized light and Xenon-ray of the stellate ganglion did not induce sympathetic blockade in dogs.

Animals↗
PubMed2000

The expression of ion channel mRNAs in skeletal muscles from patients with myotonic muscular dystrophy.

We investigated gene expression patterns of ion channels including the apamin-sensitive small-conductance Ca(2+)-activated K(+) (SK3) channel, the adult isoform of the skeletal muscle Na(+) channel (SkM1), the fetal isoform of skeletal muscle Na(+) channel (H1), and the Cl(-) channel (ClC-1) by using the semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) for muscle samples from patients with adult onset myotonic dystrophy (DM), amyotrophic lateral sclerosis, and polymyositis. Patients with DM showed a significant increase in SK3 mRNA but not in mRNAs for other ion channels. The increased expression of SK3 gene in DM did not correlate with H1, the marker of muscle denervation, or the percentage of type 2C fiber, the marker of muscle regeneration.

Adult↗
PubMed2000

Intrathecal administration of neutralizing antibody against Fas ligand suppresses the progression of experimental autoimmune encephalomyelitis.

A therapy aimed at blocking the Fas/Fas ligand (FasL) system was investigated using a relapsing form of experimental autoimmune encephalomyelitis (EAE) in mice, an animal model of multiple sclerosis (MS). Intracisternal administration of neutralizing antibody against FasL during the progression phase of EAE significantly reduced the severity of the disease with milder inflammation and myelin breakdown in the central nervous system (CNS). These results raised the possibility that the Fas/FasL system might contribute to tissue destruction in the CNS in the acute phase of EAE and that the intrathecal administration of neutralizing antibody against FasL may be beneficial for suppression of the acute phase of MS.

Acute Disease↗
PubMed2000

Enhancement of Th2 response in IL-6-deficient mice immunized with myelin oligodendrocyte glycoprotein.

To investigate the mechanism for the resistance of IL-6-deficient mice to experimental autoimmune encephalomyelitis (EAE), we examined the production of cytokines in lymph nodes (LNs) of wild-type and IL-6-deficient mice immunized with myelin oligodendrocyte glycoprotein (MOG) by reverse transcriptase-polymerase chain reaction analysis. Significant up-regulation of IL-4 production and down-regulation of IFN-gamma production were found in LNs from IL-6-deficient mice as compared to LNs from wild-type mice. Administration of IL-6, which caused typical EAE in IL-6-deficient mice immunized with MOG, reduced IL-4 production but did not restore IFN-gamma production in LNs of IL-6-deficient mice. These results implied that the resistance of IL-6-deficient mice to EAE might be mainly due to enhancement of Th2 response.

Animals↗
PubMed2000

Appropriate method of administration of propofol, fentanyl, and ketamine for patient-controlled sedation and analgesia during extracorporeal shock-wave lithotripsy.

PURPOSE: The aim of this study was to identify the appropriate method for administering propofol, fentanyl, and ketamine (PFK) for patient-controlled sedation and analgesia (PCSA) during extracorporeal shock-wave lithotripsy (ESWL). METHODS: Twenty-one unpremedicated patients were randomly assigned to three groups that received different drug administration regimens. (group 1: low loading dose and high demand bolus, group 2: high loading dose and demand bolus, group 3: high loading dose and low demand bolus). RESULTS: The patients in all groups were hemodynamically stable during ESWL. Oxygen desaturation was recognized in all groups, but was avoided by 2 l.min(-1) of oxygen supply via a nasal prong. The total administration dose of the drugs was significantly higher ( P < 0.05) in group 2 than in groups 1 and 3. The median level of sedation was the same, but the episodes of oversedation were not recognized in group 3 ( P < 0.05). A significant difference in the frequency of episodes of oversedation was found between groups 2 and 3 ( P < 0.05). The results were good or excellent for almost all patients, and were assessed as fair by only one patient in group 2. CONCLUSION: We concluded that the method used for group 3 is the most appropriate for administering PFK for PCSA during ESWL.

Clinical Trial↗
PubMed2000

Nitric oxide production of rat Leydig and Sertoli cells is stimulated by round spermatid factor(s).

In this study, we provide evidence of cell-to-cell interaction between rat germ cells and Leydig or Sertoli cells in relation to nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) messenger RNA (mRNA) expression. As a result of being cultured in a round spermatid-conditioned medium (RSd-CM), NO production in both Leydig and Sertoli cells increased in proportion to the length of the culture period. iNOS mRNA expression in both types of cells also increased in a dose-dependent manner as a result of being cultured with RSd-CM. This increase was detected as early as 3 h and was maintained up to 24 h. In contrast, neither NO production nor iNOS mRNA increased in either type of cell following culture in a pachytene spermatocyte-conditioned medium (PS-CM). Our findings suggest that RSd may control NO production of Leydig and Sertoli cells. This cell-to-cell interaction may be an important mechanism of regulation of testicular function.

Animals↗
PubMed2000

Effect of hypoxia on nitric oxide production and its synthase gene expression in rat smooth muscle cells.

It has not been clarified yet as to whether hypoxia and inflammation affect NO synthesis. In this study, we investigated the transcription of inducible nitric oxide synthase (iNOS) mRNA and the production of nitric oxide (NO) in rat smooth muscle cells (SMCs) cultured under hypoxic conditions in the presence and absence of proinflammatory cytokine interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS). We found that hypoxia inhibited the production of NO but did not affect the transcription of iNOS mRNA in rat SMCs treated with IFN-gamma, LPS, or both. These results indicate that O(2) is involved in the regulation of NO synthesis in inflammatory tissues.

Animals↗
PubMed2000

Attenuation of second sound in superfluid 3He-A1

The attenuation of second sound (spin-entropy) wave in the superfluid A1 phase has been measured in magnetic fields up to 11 T and to sufficiently high frequency to observe the bulk attenuation proportional to the square of frequency. The measured attenuation coefficient is compared with the existing theories of hydrodynamics and dissipative coefficients. The resulting "excess" attenuation is discussed in terms of the temperature dependent spin diffusion coefficient in the superfluid.

Journal Article↗
PubMed2000

The effect of apoptosis inhibitors on experimental autoimmune encephalomyelitis: apoptosis as a regulatory factor.

The effect of apoptosis inhibitors on experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis, was investigated by intraperitoneal or intracisternal administration of apoptosis inhibitors Ac-YVAD-cmk and zVAD-fmk. After onset of the disease, these agents had no suppressive effect on EAE and resulted in impaired recovery or earlier relapse. Histological examination revealed that administration of zVAD-fmk suppressed the apoptotic death of inflammatory cells in the central nervous system (CNS) of mice with EAE. The results indicated that the apoptotic elimination of infiltrated cells in the CNS might be one of the recovery mechanisms in EAE.

Amino Acid Chloromethyl Ketones↗
PubMed2000

Structure-activity relationship in potentially anti-tumor promoting benzalacetone derivatives, as assayed by the epstein-barr virus early antigen activation.

The in vitro anti-tumor promoting activities of antimutagenic benzalacetone (4-phenyl-3-buten-2-one), its monosubstituted derivatives and related compounds, cinnamaldehydes and cinnamic acids, were evaluated by determining the inhibitory effect on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. In this short-term assay, benzalacetone, which is the basic structure of dehydrozingerone (one-half analog of curcumin) inhibited the EBV-EA activation; the IC(50) value, the molar ratio of benzalacetone to TPA needed for inhibiting 50% of positive cells activated with 32 pmol TPA, was 129. IC(50) values of 2- and 4-methoxybenzalacetones were about one-half of that of benzalacetone and the methoxy compounds were more effective than hydroxybenzalacetones. IC(50) values of chloro- and trifluoromethyl-benzalacetones were higher than that of benzalacetone, indicating that these compounds are weaker inhibitors. In addition, the position of a substituent on the benzene ring affected the inhibitory effect. In benzalacetone derivatives substituted by a hydroxy-, methoxy-, chloro- or trifluoromethyl group, the 2-substituted derivatives exhibited the strongest inhibitory effect, followed by the 3- and the 4-substituents. Cinnamic acid derivatives also decreased the inhibitory effects in the same order. In the side chain of benzalacetone, the terminal group adjacent to the carbon-carbon double bond also affected the inhibitory effect. The conversions of the methylketone to aldehyde and carboxyl groups, i.e., cinnamaldehyde and cinnamic acid, increased the inhibitory effect: the IC(50) values were about one-third of that of benzalacetone. beta-Methyl styrene, which in the side chain has no carbonyl group adjacent to the double bond, inhibited the EBV-EA activation at the concentration of about one-third of that of benzalacetone, indicating that the carbonyl group negatively affects the inhibitory effect. This agreed with the previous observation between isoeugenol and dehydrozingerone, 4-hydroxy-3-methoxy derivatives of beta-methyl styrene and benzalacetone, respectively. The mechanism of the EBV-EA activation inhibition was discussed by being compared with the inhibition of mutagenesis for which the unsaturated bonded-carbonyl system is necessary.

Acrolein↗