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Biomedical subjects

T Ishizu

Publications and source records attributed to T Ishizu.

At least 19 recordsLinked to original sources
PubMed2001

Inhibitors of platelet lipoxygenase from Ponkan fruit.

An activity-guided separation for inhibitors of rat platelet 12-lipoxygenase led to the isolation of two compounds, 4-O-feruloyl-5-O-caffeoylquinic acid (IC50; 5.5 microM) and methyl 4-O-feruloyl-5-O-caffeoylquinate (IC50; 1.9 microM) from the peel of Ponkan fruit (Citrus reticulata). The complete structure of each phenolic ester was determined by NMR spectroscopy [1H and 13C NMR spectra, 1H-1H correlation spectroscopy (COSY), 1H-detected heteronuclear multiple quantum coherence (HMQC), and heteronuclear multiple bond connectivity (HMBC) spectroscopies] and other spectral methods.

Animals↗
PubMed2001

The effect of breath termination criterion on breathing patterns and the work of breathing during pressure support ventilation.

UNLABELLED: With pressure support ventilation (PSV), each PSV breath is flow-cycled, and the breath termination criterion (TC) is usually nonadjustable. When TC does not match the interaction between the patient's inspiratory-expiratory efforts to the opening and closing of the inspiratory and expiratory valves, patient-ventilator asynchrony may occur, and the work of breathing (WOB) may increase. Therefore, we studied the effect of TC on breathing patterns and WOB during PSV in eight patients with acute respiratory distress syndrome or acute lung injury. We studied five levels of TC during PSV-1%, 5%, 20%, 35%, and 45% of the peak inspiratory flow. With increasing levels of TC, the tidal volume decreased and respiratory frequency increased, along with a decrease in duty cycle. WOB markedly increased with increasing levels of TC from 0.31 +/- 0.12 J/L with TC 1% to 0.51 +/- 0.11 J/L with TC 45%. Premature termination with double breathing occurred in one patient with TC 35% and four patients with TC 45%. Delayed termination with a duty cycle of >0.5 occurred in two patients with TC 1%. In conclusion, the proper adjustment of TC improves patient-ventilator synchrony and decreases WOB during PSV. IMPLICATIONS: Although termination criterion (TC) is usually nonadjustable, it influences the effectiveness of pressure support ventilation for mechanical ventilation. The proper adjustment of TC is crucial to improve patient-ventilator synchrony and decrease work of breathing. TC 5% of the peak inspiratory flow may be the optimal value for patients with acute respiratory distress syndrome or acute lung injury.

Aged↗
PubMed2001

Estimating pulmonary capillary wedge pressures using Doppler variables of early diastolic left ventricular inflow.

The present study was performed to determine whether a multilineal regression model based on the early diastolic transmitral flow peak velocity (E) and the propagation velocity of early diastolic inflow (PV) could estimate the pulmonary capillary wedge pressure (PCWP). PCWP and Doppler variables were simultaneously recorded in 30 patients. PCWP was estimated by multilinear regression analysis using E and PV. The predictive accuracy of the equation obtained from the analysis was tested prospectively in a separate group of 65 patients divided into 3 groups: left ventricular (LV) systolic dysfunction (Group A), LV hypertrophy (Group B), and preserved systolic function without hypertrophy (Group C). The initial results obtained in groups B and C, respectively, were: r=0.77; r=0.81. These results indicate that a multilinear regression model based on E and PV is a noninvasive method of accurately estimating PCWP in a variety of cardiac disease states.

Adult↗
PubMed2001

[A patient with restless legs syndrome/periodic limb movement successfully treated by wearing a lumbar corset].

We report a 77-year-old woman with restless legs syndrome(RLS) and periodic limb movement(PLM). From 62 years of age, she was awakened by tingling and involuntary movement in her legs during sleep. There symptoms disappeared when she stood up and walked. She was treated with clonazepam (2.5 mg/day) and valproate (400 mg/day) at 77 years of age, and the symptoms clearly ameliorated. However, she developed mild truncal ataxia and was referred to our hospital. On admission, neurological examination revealed Babinski and Chaddock signs bilaterally with depressed tendon reflexes in the lower limbs, mild truncal ataxia and horizontal gaze nystagmus. She did not present with involuntary movement of the legs while taking the anti-epileptic drugs. Cessation of these drugs alleviated the truncal ataxia and nystagmus, but reexacerbated abnormal sensation with involuntary movement in her legs during sleep. The involuntary movements in her legs were slower than myoclonus and resembled a Babinski reflex (duration about 1 second), and they appeared periodically (around every 30 seconds) in I-II sleep stages. Neither brain MRI nor EEG detected any abnormality. Cervical MRI revealed focal compression of the spinal cord by osteophytes at C5-C6 (more severe on the left side). Motor evoked potentials with transcranial magnetic stimulation revealed a mild delay in the central conduction time (CCT), which was more prolonged on the left side. She was thus diagnosed as having RLS/PLM with involvement of the bilateral pyramidal tracts. Although nerve conduction studies did not detect any abnormality in the peripheral nerves, RLS/PLM of the left leg was induced by electric stimulation of the left tibial nerve. Because she did not want medication any more, we treated her with a lumbar corset, hoping that wearing a lumbar corset might induce contraction of the truncal muscles that would mimic standing and walking or might produce additional sensory input that would induce a 'sensory trick'. Consequently, her abnormal sensation and involuntary movement during sleep as well as the stimulation of the tibial nerve disappeared. Wearing a lumbar corset may inhibit the excitability of the spinal cord that generates RLS/PLM, though the level of sensory input by the corset was higher than the input level of abnormal sensation in her legs. A lumbar corset may be a useful alternative choice for patients with RLS/PLM, who cannot tolerate either anti-epileptic or dopaminergic drugs.

Aged↗
PubMed2000

Prevalence of Japanese dialysis patients with an A-to-G mutation at nucleotide 3243 of the mitochondrial tRNA(Leu(UUR)) gene.

BACKGROUND: A high prevalence of an A-to-G mutation at nucleotide 3243 of the mitochondrial genome in patients with diabetes mellitus (DM) and/or deafness has been reported previously. We investigated the prevalence of this mutation in Japanese dialysis patients with associated DM and/or deafness. METHODS: We studied 106 dialysis patients with DM, 26 with DM and deafness, and 26 with deafness alone, using peripheral leucocytes to detect an A-to-G transition at nucleotide 3243 of the mitochondrial gene. RESULTS: We identified this transition in 1 of 26 patients with DM and deafness. None of the 106 DM or 26 dialysis patients with deafness but no DM was positive for this mutation. A 42-year-old male patient on continuous ambulatory peritoneal dialysis (CAPD) who carried this mutation had a 20-year history of sensory hearing loss as well as hypertrophic cardiomyopathy. CONCLUSION: We found that a mitochondrial gene mutation at nucleotide 3243 was present in one dialysis patient with NIDDM and deafness. The prevalence of this mutation was found to be below 1% in diabetic end-stage renal disease patients in Japan.

Adult↗
PubMed2000

Cytokines and T-cell responses in superantigen-related glomerulonephritis following methicillin-resistant Staphylococcus aureus infection.

BACKGROUND: We have previously reported that 10 patients who developed glomerulonephritis (GN) in association with methicillin-resistant Staphylococcus aureus (MRSA) infection showed a marked increase in DR+CD4+ and DR+CD8+ subsets of T cells and in T cells expressing several T-cell receptor (TCR) V beta+cells, perhaps representing V beta-specific T-cell activation by MRSA-derived superantigens (Kidney Int 1995; 47: 207-216). In this study we examine cytokine levels, T-lymphocyte subsets, natural killer NK cells, memory T cells, and the expression of IL-2 receptors in order to better understand the role of bacterial superantigens and cytokines in the pathogenesis of MRSA-associated GN. METHODS: Twenty-two patients with MRSA infection who later developed GN caused by staphylococcal enterotoxin were evaluated immunologically in comparison with patients whose MRSA infection was not followed by GN (non-GN group) and normal individuals. RESULTS: Among peripheral lymphocytes, the frequency of T cells expressing several TCR V betas, especially V beta 5-family TCR, was higher in the GN group than in both the non-GN group and the normal healthy control group. GN patients also showed increased serum levels of several cytokines, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-2, IL-6, IL-8, and IL-10, which have been implicated in the onset of nephritis. Memory cells, and IL-2 receptors also were elevated in the GN group. CONCLUSION: These results suggest that T cells activated by MRSA-derived staphylococcal enterotoxins and subsequent production of cytokines may play an important role in the pathogenesis of MRSA-associated GN.

Adult↗
PubMed2000

[Chirality of natural products: hyoscyamine and scopolamine].

Monthly changes of the content-ratio between S-(-)- and R-(+)-hyoscyamine as well as those between S-(-)- and R-(+)-scopolamine in the leaves of Datura metel L. cultivated in the field, were quantitatively analyzed by the use of HPLC with a chiral adsorbent. It was found that S-(-)-isomer was predominant for hyoscyamine and the ratio of R-(+)-isomer gradually increased during the growth, whereas in the case of scopolamine, S-(-)-isomer was the sole one found throughout the cultivation period. The 1H-NMR study in the CD3OD solution has suggested that S-(-)-hyoscyamine (1) and S-(-)-scopolamine (2) take a "face-to-face" conformation between their tropane skeletons and the benzene rings of the tropic acid moieties. In the presence of an equimolar NaOD in the CD3OD solution, the racemization at C-2' of 1 and 2 proceeded more rapidly than the hydrolysis at the tropic acid ester bond, presumably due to the steric hindrance caused by their "face-to-face" conformations. In the D2O and H2O solutions, on the other hand, the racemization and the hydrolysis of 1 proceeded smoothly, while those of 2 did not occur. It has been supposed that these individual reaction manners are ascribable in considerable extent to the different basicity of N atom in each tropane skeleton of 1 and 2 and to stronger intramolecular hydrogen bond occurring between the carbonyl oxygen at C-1' and the hydroxyl group at C-3' in the tropic acid moiety of 1.

Atropine↗
PubMed2000

[Usefulness of nitrendipine and its effects on quality of life and brain blood flow in elderly hypertensive patients].

There are many reports on the efficacy of Ca-antagonists for treatment of elderly essential hypertension. In particular, many studies have noted the beneficial effects of antihypertensive therapy on the quality of life (QOL). Nevertheless, there are no reports on antihypertensive therapy regarding the relationship between brain blood flow (BBF) and QOL. Therefore, we examined the efficacy of nitrendipine, a Ca-antagonist, on the brain blood flow and QOL, and its side effects in elderly essential hypertensive patients. The subjects were 17 (males: 4, females: 13) patients with untreated hypertension of WHO stage I or II, aged 70 years or older. The mean dose of nitrendipine was 9.4 +/- 0.4 mg daily. Before and 6 months after treatment, we examined blood pressure (BP), heart rate (HR), echocardiography (left ventricular mass index [LVMI], % fractional shortening [% FS]), plasma noradrenaline (Nad), plasma renin activity (PRA), BBF using the IMP-ARG method with BBF scintigraphy, and QOL was examined with a questionnaire. Two patients were excluded from this study because 1 had no decrease in BP, and another was moved to a different hospital. BP significantly decreased from 178/93 to 137/77 mmHg, but HR was not changed after treatment. BBF significantly increased from 37.0 +/- 4.9 to 41.0 +/- 4.9 ml/dl/min, but % FS, Nad, and PRA did not significantly change. The degree of QOL was improved by 4.2 +/- 1.2 points and there was a significant positive correlation between the changes of BBF and of QOL (r = 0.66, p = 0.04). However, moderate pharmacotherapy for BP seems to be necessary because there were 2 patients whose BBF decreased accompanied by excessive drop in BP after treatment. In conclusion, it is possible to safely use nitrendipine for elderly essential hypertensive patients. Nitrendipine has beneficial effects on BBF, and it was suggested that the increase of BBF is one of the most important factors in improvement of QOL.

Aged↗
PubMed2000

Hydroxyprolylserine derivatives JBP923 and JBP485 exhibit the antihepatitis activities after gastrointestinal absorption in rats.

It has been a desire to develop orally effective therapeutic agents that restore the liver function in chronic injury. Here we demonstrated that trans-4-L-hydroxyprolyl-L-serine (JBP923) and cyclo-trans-4-L-hydroxyprolyl-L-serine (JBP485), which was previously isolated from hydrolysate of human placenta, exhibit potent antihepatitis activity after their oral administration. The increase in bilirubin concentration and activities of liver cytosolic enzymes in serum caused by alpha-naphthylisothiocyanate intoxication in rats were significantly countered both after i.v. and oral administration of these dipeptides, whereas glycyrrhizin, which has been used in the treatment of chronic hepatitis, is active only after its i.v. administration. Antihepatitis activity of dipeptides results, at least partially, from their direct effect on hepatocytes because glutamic-oxaloacetic transaminase and lactate dehydrogenase activities in the medium of hepatotoxin-exposed primary cultured hepatocytes were reduced by these compounds. When comparing the plasma concentration-time profile of JBP923 after its i.v., oral, and portal vein injection, it is suggested that JBP923 is almost completely absorbed from gastrointestinal lumen, and hepatic first-pass removal is minor. JBP923 inhibited the proton-dependent transport of glycylsarcosine in brush-border membrane vesicles, suggesting that peptide transport system(s) may recognize JBP923. Thus, these dipeptides are potent antihepatitis reagents that are still active after oral administration and may be useful for clinical applications.

1-Naphthylisothiocyanate↗
PubMed2000

[Unexpected difficult intubation caused by a laryngeal web].

We report a case of unexpected difficult intubation in an adult caused by a laryngeal web. A 43-year-old woman with uterine myoma was scheduled for abdominal hysterectomy. After induction of anesthesia, the vocal cords were seen clearly under laryngoscopy. Although intubation was attempted several times, a 6.5 mm internal diameter tracheal tube could not be passed below the level of the vocal cords because of resistance, and we used a laryngeal mask during anesthesia. Next morning after the operation, she developed dyspnea. Bronchoscopy revealed a very narrow airway below the level of vocal cords caused by a laryngeal web. Tracheostomy was performed. Two weeks later, tracheostomy was closed without any sequela.

Adult↗
PubMed1999

Effect of histamine H2-receptor antagonist on the phosphorus-binding abilities of calcium carbonate and calcium lactate in hemodialysis patients.

The effect of histamine H2-receptor antagonist (famotidine) on the phosphorus-binding abilities of calcium carbonate and calcium lactate were examined in 13 chronic hemodialysis patients. In seven patients receiving calcium carbonate, famotidine (20 mg/d) was given because of gastroduodenal disorders, and calcium carbonate was replaced with calcium lactate as a phosphorus binder after 4 wk of treatment with famotidine. With the 4-wk administration of famotidine accompanied by calcium carbonate, the serum phosphorus level increased from 6.3+/-0.9 to 7.1+/-0.5 mg/dl (P<0.05). However, with the substitution of calcium lactate, the serum phosphorus level decreased significantly when compared to that before substitution (6.3+/-0.2 and 6.0+/-0.9 mg/dl after 4 and 8 wk of substitution, respectively), despite continued administration of famotidine. Serum calcium, creatinine, alkaline phosphatase, high sensitive parathyroid hormone, blood urea nitrogen, arterial blood pH, and bicarbonate were not significantly altered during the trial period. In six control patients treated with calcium carbonate alone, there were no statistical changes in serum calcium and phosphorus levels after substitution of calcium lactate for calcium carbonate. These results suggest that famotidine significantly affects the phosphorus-binding ability of calcium carbonate, but not that of calcium lactate. A careful observation of changes in the serum phosphorus level should be required in hemodialysis patients receiving calcium carbonate and histamine H2-receptor antagonists. Calcium lactate may be useful as a phosphorus binder in such hemodialysis patients.

Adult↗
PubMed1999

[A case of nephrotic syndrome associated with myasthenia gravis and malignant thymoma].

A 26-year-old woman who presented facial and lower leg edema associated with massive proteinuria was admitted to our hospital in February 1992. Nine months before this admission, she exhibited myasthenia gravis and malignant thymoma, and underwent total thymectomy. On admission, there was no symptom of myasthenia gravis. She was diagnosed as having nephrotic syndrome and the first renal biopsy was performed. The histological findings showed membranous nephropathy. Immunofluorescent microscopy revealed that IgG and C3 were stained in a granular pattern in the periphery, and subepithelial deposits were observed in the basement membrane of the glomerulus by electron microscopy. With the administration of prednisolone, proteinuria disappeared and the nephrotic syndrome remitted. She was admitted again in January 1993 due to proteinuria and lower leg edema following cystitis. The findings of the second renal biopsy were unremarkable. She was administered cyclosporin A to improve the nephrotic syndrome and to reduce the side effects of prednisolone. The proteinuria disappeared again and this effect was dependent on the dose of cyclosporin A. Since the first administration, no symptoms of myasthenia gravis or malignant thymoma have been observed. The relationships among myasthenia gravis, malignant thymoma and nephrotic syndrome were examined. Although the first renal biopsy findings showed membranous nephropathy, from the therapeutic responses of both prednisolone and cyclosporin A, the main course of proteinuria in this case may have been due to minimal change nephrotic syndrome. We consider this case of nephrotic syndrome to be important considering its etiology and the relationship between the histological findings and its clinical course.

Adult↗
PubMed1998

Effects of FK506 on experimental membranous glomerulonephritis induced by cationized bovine serum albumin in rats.

BACKGROUND: There have been no reports on the effect of FK5 06, a new immunosuppressive agent, on experimental membranous glomerulonephritis (MN) induced by an exogenous antigen. Therefore we investigated the effects of FK506 on MN induced by cationized bovine serum albumin (C-BSA) in rats. METHODS: Two weeks after the rats were immunized with 1 mg of C-BSA and Freund's complete adjuvant, they received intravenous injections of 3 mg/kg of C-BSA 3 times weekly for 4 weeks. Rats were divided into four groups: group A (n = 5) received intramuscular injections of 3 mg/kg of FK506 daily for 5 days beginning 2 days before the first immunization; group B (n =4) received 1 mg/kg of FK506 daily for 2 weeks beginning 2 weeks after the first immunization; and group C (n =4) received 1 mg/kg of FK506 daily for 2 weeks beginning 4 weeks after the first immunization. Group D (n = 5) received no FK506 and served as the control group. Rats were sacrificed 8 weeks after the first immunization. RESULTS: Administration of FK506 in the preimmunization stage almost completely suppressed the development of MN in group A. Histological findings in groups B and C were similar to those in group D, the control group. However, urinary protein excretion was significantly lower in group B (24+/-46 mg/day) and C (220+/-44 mg/day) than in group D (330+/-61 mg/day). Expression of intracellular adhesion molecule-1 in glomeruli and the number of leukocyte functioning-associated molecules-1 were significantly decreased in groups A, B, and C compared with the control group. Administration of FK506 was not associated with any significant side-effects or histological abnormalities. The whole-blood trough levels of FK506 in groups B and C were 9.1 ng/ml and 9.2 ng/ml respectively. CONCLUSIONS: The efficacy of FK506 was significantly increased when the drug was administered in the early phase of immunization in this model. The present study suggests that FK506 may be useful in patients with intractable nephrotic syndrome such as MN.

Animals↗
PubMed1998

[Perioperative management of two patients with severe dilated cardiomyopathy].

We report perioperative management of two patients with severe dilated cardiomyopathy belonging to the group IV of classification of Inoh (ejection fraction 18% and 30%). In the preoperative period, they developed severe congestive heart failure. Dopamine, dobutamine, and furosemide were given to improve cardiac function. Anesthesia was performed safely under continuous cardiac output and mixed venous saturation monitoring. We consider that preoperative evaluation and management are very important to prevent intraoperative and postoperative complications in patients with severe dilated cardiomyopathy.

Aged↗
PubMed1998

[Recurrent nerve palsy after endotracheal intubation].

We encountered left recurrent nerve palsy in four patients who had undergone surgery unrelated to the course of the vagus nerve or recurrent nerve, during which they had received endotracheal anesthesia. They were intubated without difficulty and underwent surgery without trouble, but postoperatively they all complained of hoarseness. We used a disposable ENTRASOFT endotracheal tube with high volume, low-pressure cuff in three patients and a disposable PORTEX endotracheal tube with low volume, standard cuff in one patient. In three patients recurrent nerve palsy healed completely within two months after the operation, and one patient was recovering from the palsy on the twentieth day after the operation. We believe that the most plausible explanation of recurrent nerve palsy is the excessive pressure from the inflated endotracheal tube cuff on the intralaryngeal course of the anterior branch of the recurrent nerve. Monitoring cuff pressure is most important to prevent recurrent nerve palsy after endotracheal intubation.

Adult↗
PubMed1996

Comparison of mutagenic activity of bile between Chilean and Japanese female patients having cholelithiasis.

The mutagenic activity of bile was compared between Chilean and Japanese female patients having cholelithiasis by the Ames assay using Salmonella typhimurium tester strain TA98 in the presence of S9 mix with blue rayon adsorption technique. A reason for conducting the present investigation is that Chile and Japan have the highest mortality rates for the gallbladder cancer (GBC) in the world. Of 24 bile samples collected in Chile, 20 (83.3%) samples showed mutagenicity. In the case of Japanese bile, 21 (80.8%) of 26 and 5 (19.2%) of 26 cases were mutagenic in samples from high- and low-risk areas for GBC, respectively. Therefore, both the Chilean and the Japanese samples collected in high-risk areas showed higher mutagenic rates than the Japanese ones in a low-risk area, with a statistical significance (p < 0.001), chi-square test). The average number of revertant colonies were 128 +/- 92 (mean +/- SD), 62 +/- 14 and 66 +/- 13, respectively, when the blue rayon extracts of 200 microliters bile were applied to the Ames test. Thus, Chilean bile had a tendency to show a higher mutagenic activity than Japanese.

Adult↗
PubMed1996

Mutagenicity of 24-hour duplicate of Japanese diet.

In order to elucidate the genotoxicological characteristics of the Japanese diet, the mutagenicity of 24-h duplicate of the diet samples were investigated. The mutagenicity of blue rayon extract was examined in the Ames Salmonella/microsome assay. Thirty-two (91.4%) of 35 samples revealed mutagenicity toward Salmonella typhimurium TA98 in the presence of S9 mix. The mutagenic activities showed significant correlations with the consumption rates of broiled fish (r = 0.517, p = 0.0021) and broiled meat (r = 0.494, p = 0.0036). In other test conditions, 6 (17.1%), 5 (14.3%) and 8 (22.9%) samples were mutagenic to Salmonella typhimurium TA98 without S9 mix, TA100 with S9 mix and TA100 without S9 mix, respectively. Findings in the present study suggest that high consumption of broiled fish and broiled meat are important as the source of mutagens/carcinogens in the Japanese diet. In the present study, however, biological inference of these findings could not be made in relation to the occurrence of cancers, especially of the gastric cancer, which is the most prevalent form of cancer in Japan.

Aged↗