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Biomedical subjects

T Nozawa

Publications and source records attributed to T Nozawa.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Recurrent spontaneous rupture of the urinary bladder: a case report].

The patient was a 67-year-old woman who had undergone radical hysterectomy and postoperative radiotherapy for cervical cancer at the age of 46 years. Spontaneous rupture of the urinary bladder occurred twice in 1997, and conservative treatment was performed on each occasion. She was admitted to our hospital for the third time of spontaneous rupture of the urinary bladder. She underwent bilateral cutaneous ureterostomy because of panperitonitis and paralytic ileus. A review of 11 cases of recurrent rupture of the urinary bladder reported in Japan including the present case revealed that, patients who had been conservatively treated tended to be subject to recurrence. However, the risk of recurrence remains when a partial cystectomy is performed. Therefore, especially in recurrent cases, augmentation cystoplasty or urinary diversion should be considered as the treatment for spontaneous rupture of the urinary bladder due to radiation cystitis.

Aged↗
PubMed2000

[Transurethral removal of the ureter by the intussusception method in the treatment of renal pelvic and ureteral tumors].

Between August 1986 and December 1998, 19 patients who had renal pelvic and upper ureteral tumors were treated with nephrectomy and transurethral removal of the ureter using the intussusception method. Removal of the ureter failed in 5 patients because of excessive ablasion of the ureter or insufficient electro-resection around the ipsilateral ureteral orifice. Excluding those patients, the safety of the operation and the intravesical recurrence were compared with the outcome in 12 patients undergoing partial cystectomy for similar tumors. The mean operating time was not significantly shorter with the intussusception method compared with partial cystectomy (190.4 versus 251.3 minutes), but the mean blood loss was significantly smaller (187.5 versus 460.2 ml) and the intussusception method did not require a blood transfusion. The mean term of hospitalization was 20.3 days for patients treated by the intussusception method which was significantly shorter than that for patient undergoing partial cystectomy (25.4 days). Intravesical recurrence was found in seven patients (50%) treated by the intussusception method and the 1- and 5-year recurrence-free rates were 69.2% and 30.8% respectively. There was no significant difference in the recurrence-free rates between the two surgical techniques. These results suggest that the intussusception method is superior to partial cystectomy in decreasing the operating time, blood loss and term of hospitalization. It can be an attractive option in selected cases, without increasing the risk of intravesical recurrence.

Adult↗
PubMed2000

[A case report of skeletal muscle metastasis of renal cell carcinoma effectively treated with interferon-alpha].

The skeletal muscle is a very rare site of metastasis in renal cell carcinoma. We report the third case of skeletal muscle metastasis of renal cell carcinoma effectively treated with interferon-alpha. The patient was a 74-year-old woman who had undergone radical nephrectomy on the left side for renal cell carcinoma on April 23, 1990, and had been observed as an outpatient. In June 1997, she was admitted with a diagnosis of metastasis in the left great adductor muscle and right sixth rib, as well as multiple lung metastasis. The metastatic lesion in the great adductor muscle decreased in size by more than 50% following concomitant intramuscular administration of natural interferon-alpha (nIFN-alpha). In the other metastatic lesions, nIFN-alpha-sensitive and resistant metastatic foci were intermingled. Thus, the primary focus in the present study was presumably composed of several clones with different sensitivities to nIFN-alpha.

Aged↗
PubMed2000

[Abnormal Q wave in the right precordial leads unmasked during right bundle branch block in a patient with anteroseptal myocardial infarction: a case report].

Electrocardiography in a 77-year-old woman showed small R waves in leads V1-V3 3 hours after the onset of acute anteroseptal myocardial infarction. Abnormal Q waves appeared in leads V1-V3 only during intermittent right bundle branch block. The normal septal force disappeared after transmural septal infarction and a small force of right ventricle origin became apparent as a small R wave in V1. Right bundle branch block delayed activation of right ventricle, and thereby deleted the initial R wave and unmasked the Q wave of the septal infarction. Appearance of a Q wave in leads V1-V3 with right bundle branch block should not be assumed to reflect the extension of myocardial infarction.

Aged↗
PubMed2000

[Automatic analysis of sleep EEG].

Since a manual of standardized scoring system for sleep stage was reported by APSS, the sleep researches remarkable advanced. But it took sleep researchers many times and effort to analysis of numerous data. The digital and computer technique were advanced about 10 years, so that, paper polysomnography(PSG) has been replaced with computerized polysomnography(PSG). The computerized PSG is useful for sleep stage scoring and storage of data. It is pointed out that the correctness of computerized analysis unfortunately is less than visual. Generally, computerized analysis is performed to apply the manual of APSS. This manual is not able to computerized analysis. Because this manual was developed for visual. In 1999, Japanese sleep research society was reported a manual of sleep stage scoring for computerized analysis which was modified the manual of APSS. It is expected to development of computerized PSG system which is able to yield the result similar to that obtained with visual.

Electroencephalography↗
PubMed2000

[Consideration on neuroimaging and functional diagnosis in cerebrovascular disorder].

The electroencephalogram(EEG) has been one of the important clinical examination in cerebrovascular disorder(CVD). Since X-ray computed tomography(CT) was introduced in the 1970's, the numbers of EEG examination decreased in Japan. In the present, the diagnosis of acute CVD is done by neuroimaging examinations which generally are CT, magnetic resonance imaging(MRI) and at times, single photon emission computed tomography(SPECT). But EEG examination is necessary for estimate of brain function in acute and/or chronic CVD. Only EEG examination is able to confirm epileptic seizure, sleep-wake disorder and disturbance of consciousness. alpha-coma and spindle coma are peculiar disturbance of consciousness and appear in acute CVD. REM sleep behavior disorder(RBD) sometimes appear in chronic CVD. The characteristic of RBD is violent or injurious behavior during REM sleep. Polysomnography demonstrates abnormal REM sleep without loss of atonia. Both neuroimaging and functional diagnosis have been to perform to estimate in CVD same as in the other central nervous disorders.

Cerebrovascular Disorders↗
PubMed1999

Interaction of photosynthetic pigments with various organic solvents. Magnetic circular dichroism approach and application to chlorosomes

Magnetic circular dichroism (MCD) and absorption spectra have been measured on three intact photosynthetic pigments with the chlorin ring as macrocycle: chlorophyll a, bacteriochlorophyll c and d, in various hydrophilic organic solvents. The MCD intensity of a Qy(0-0) transition for the Mg chlorin derivative was sensitive to the coordination state of the central Mg atom by the solvent molecules. The coordination number has been characterized in terms of the relationship between the ratio of Qy(0-0) MCD intensity to its dipole strength (B/D) and the difference in energies of Qx(0-0) and Qy(0-0) transitions. This relationship depends not only on the coordination number of the magnesium (Mg) atom but also on the coordination interaction of the solvent molecules to the Mg atom, and can clarify the spectroscopic change of chlorosomes by alcohol treatment. We propose that the correlation between the MCD intensity of Qy(0-0) transition and the energy difference can be used as a new measure for determining the coordination number of the Mg atom and for estimating the interaction strength of the Mg atom with solvent molecules.

Journal Article↗
PubMed1999

Modulation of left ventricular diastolic distensibility by collateral flow recruitment during balloon coronary occlusion.

OBJECTIVES: The goals of this study were to elucidate the scaffolding effect of blood-filled coronary vasculature and to determine the functional role of recruited collateral flow in modulating left ventricular (LV) distensibility during balloon coronary occlusion (BCO). BACKGROUND: Although LV distensibility is an important factor affecting acute dilation after myocardial infarction, the response of LV diastolic pressure-volume (P-V) relations to coronary occlusion is inconsistent in humans. METHODS: Micromanometer and conductance derived LV P-V loops were serially obtained from 16 patients undergoing percutaneous transluminal coronary angioplasty. Coronary collateral flow recruitment was angiographically evaluated by contralateral and ipsilateral contrast injection during BCO. RESULTS: In the group with poor collateral flow (grades 0-I; n = 8), BCO resulted in a downward and rightward shift of the diastolic P-V relations, where end-diastolic volume (EDV) increased by 13% (p < 0.05) without appreciable change in end-diastolic pressure (EDP; 18 +/- 6 to 18 +/- 8 mm Hg). In contrast, BCO in the group with good collateral flow (grades II-III; n = 8) shifted the diastolic P-V relations upward to the right with a concomitant increase in minimal pressure (min-P; 6 +/- 4 to 10 +/- 5 mm Hg, p < 0.05), EDP (15 +/- 7 to 21 +/- 9 mm Hg, p < 0.05) and EDV (+/- 10%, p < 0.05). Reactive hyperemia after balloon deflation caused a rapid and parallel upward shift of the diastolic P-V relations with a marked increase in min-P and EDP, especially in the group with poor collateral flow, before any improvement in LV contraction or relaxation abnormalities. CONCLUSIONS: Grades of coronary filling, either retrograde or anterograde, abruptly modulate LV distensibility through the rapid scaffolding effect of coronary vascular turgor.

Aged↗
PubMed1999

Time-varying spectral analysis of heart rate and left ventricular pressure variability during balloon coronary occlusion in humans: a sympathoexicitatory response to myocardial ischemia.

OBJECTIVES: We assessed time-varying spectral components of heart rate and left ventricular (LV) pressure variability during coronary angioplasty to elucidate dynamic autonomic responses to transient myocardial ischemia. BACKGROUND: Sympathoexcitatory reflexes elicited by acute coronary occlusion are rarely addressed in the clinical settings because of a lack of technique to monitor transient changes in sympathetic activation. METHODS: RR interval and LV pressure and volume were serially recorded in 14 patients with effort angina during balloon coronary angioplasty. Wavelet analysis was applied for determination of nonstationary spectral components of RR interval and LV peak pressure variability. RESULTS: The wavelet analysis revealed that coronary occlusion provoked low-frequency (LF) fluctuations of RR interval (seven patients) and LV peak pressure (six patients) at 0.06 +/- 0.01 Hz, but not in the remaining patients. Following the balloon inflation, the LF component of RR interval began to increase after the onset of myocardial ischemia, peaked at about 80 s, and then declined in the late phase of inflation. Consequently, the ratio of low to high frequency component rose to be significantly greater in the LF augmentation group than in the no LF augmentation group in the middle phase of coronary occlusion. The patients with no LF augmentation had little evidence of myocardial ischemia as reflected by changes in ST segment and LV systolic function during coronary occlusion. CONCLUSIONS: The wavelet analysis of RR interval and LV pressure variability clearly showed a dynamic profile of spectral components in response to transient coronary artery occlusion. The resultant regional myocardial ischemia elicited a profound sympathoexcitatory response followed by a gradual suppression. This method provides a useful tool to gain a new insight into the nonstationary autonomic influence on the cardiovascular system.

Adult↗
PubMed1998

Dual-tracer assessment of coupling between cardiac sympathetic neuronal function and downregulation of beta-receptors during development of hypertensive heart failure of rats.

BACKGROUND: Heart failure is associated with activation of the sympathetic nervous system and downregulation of beta-receptors. However, the coupling between cardiac sympathetic neuronal function and the beta-receptor during the development of hypertensive heart failure is not clear. METHODS AND RESULTS: We determined cardiac neuronal function and beta-receptors with a dual-tracer method of [131I]metaiodobenzylguanidine (MIBG) and 125I-cyanopindolol (ICYP) in Dahl salt-sensitive (DS) and salt-resistant (DR) rats. The rats were fed an 8% NaCl diet after the age of 6 weeks. Blood pressure was raised to >200 mm Hg at 12 weeks in DS rats and remained elevated until 18 weeks, but only slightly in DR rats. Left ventricular (LV) function of DS rats was preserved at 12 weeks but deteriorated at 18 weeks. Despite a 56% reduction of cardiac norepinephrine (NE) content at 12 weeks in DS rats, neither MIBG nor ICYP uptake in DS rats was different from that of DR rats. At 18 weeks, both MIBG and ICYP uptakes decreased, by 52% and 39%, respectively, in association with 71% reduction of cardiac NE, in DS rats. MIBG uptake of the LV was homogeneous at 6 weeks but was lower in the LV endocardial regions at 18 weeks in DS rats. CONCLUSIONS: The present results indicate that cardiac sympathetic neuronal function is relatively preserved at the compensated, hypertrophic stage of DS rats but deteriorates in association with beta-receptor downregulation at the failing stage. The cardiac neuronal dysfunction occurs heterogeneously. A combination of scintigraphic portrayal of beta-receptors with MIBG should provide valuable information regarding sympathetic nerve signaling in living hearts.

3-Iodobenzylguanidine↗
PubMed1998

In situ measurements of ribulose-1,5-bisphosphate carboxylase activity by nuclear magnetic resonance.

High-resolution NMR spectroscopy is demonstrated to be capable of monitoring in situ the carboxylation reaction catalyzed by ribulose-1,5-bisphosphate carboxylase. Specific activities are determined for three enzymes from different sources containing higher plant and photosynthetic bacteria, and they are in agreement with those measured by other methods. Several important features of the reaction have been confirmed at the atomic level. A decrease in activity with time after the reaction started has also been observed for both enzymes with L8S8 and L2 structures from photosynthetic bacteria and higher plants, suggesting that the "fallover" of activity may be a more general phenomenon. 1H spectra obtained with H2O as solvent provide the most efficient quantitative measurement of the reaction product, 3-phosphoglycerate. 31P spectra give essentially the same result as 1H NMR but have the advantage of showing the degree of reaction at any time during the reaction. The incorporated carbon atom is unequivocally identified as the C-1 carbon of 3-phosphoglycerate from the 13C spectrum.

Hydrogen-Ion Concentration↗
PubMed1998

Additional possible tools for identification of proteins on one- or two-dimensional electrophoresis.

Additional, essentially chemical, identification methods of proteins in polyacrylamide gel electrophoresis are described. Two cleavages of peptide bonds were used at the C-side of aspartic acid with a 0.2% pentafluoropropionic acid (PFPA) aqueous vapor at 90 degrees C for 4-16 h, and the N-side of serine/threonine with an S-ethyl trifluorothioacetate vapor at 50 degrees C for 6-24 h. The products were analyzed by mass spectrometry-peptide mass fingerprinting. A new type of C-terminal sequencing at multisites of protein was introduced. An aqueous vapor of 90% PFPA at 90 degrees C for 2-16 h provided cleavages at the C-side of aspartic acid and the N-side of serine/threonine and simultaneous successive truncation at the C-termini of the cleaved fragments. The product resulted in C-terminal sequences at multisites in proteins by mass spectrometric analysis. The following chemical deblocking methods were used. Anhydrous hydrazine vapor at -5 degrees C for 8 h deblocked the N-formyl group, and the vapor at 20 degrees C for 4 h deblocked pyrrolidone carboxylate. N-acetylserine/threonine was deblocked by aqueous vapor of 75% PFPA at 50 degrees C for 1 h, followed by reaction with p-sulfophenylisothiocyanate at pH 6.0. These methods were applied to a variety of protein spots on polyacrylamide gels. A new stepwise C-terminal sequencing of protein from polyacrylamide gels is also described.

Amino Acid Sequence↗
PubMed1998

A new method for evaluation and dietary therapy of congenital: deficiencies of amino acid metabolic enzymes. Linear system analysis and optimization of feedback inputs for the metabolic pathways of lysine, methionine and isoleucine.

We intended to elucidate an integrated mathematical model of amino acid metabolism and we propose a system for optimization treatment of disturbed metabolic states caused by congenital enzyme deficiencies. Our analysis focused on the metabolic pathway starting at asparaginic acid proceeding to isoleucine, methionine and lysine. The rate of change in the concentration of the biochemical species was expressed as 21 linear rate equations. We obtained the rate constants and the magnitude of feedback from reported experimental data. Linear systems analysis revealed that the metabolic system under study was stable but uncontrollable. These properties were insensitive to changes in the magnitude of feedback. To show the effect of optimizing the feedback so that it minimizes the square of the concentration of the species and the control input, we analyzed the impulse response of the species, transient response and the singular value of the system for four cases; (1) at the physiological state without optimizing the feedback, (2) at the physiological state attained after optimizing the feedback, (3) at the pathophysiological state attained with enzyme deficiency states for lysine and methionine metabolism without optimizing the feedback, and (4) at the pathophysiological state attained after optimizing the feedback for enzyme deficiencies. In the enzyme deficient model, the impulse response oscillated and lasted longer than that in the physiological state. These changes appeared even in the species on other branched pathways. The singular value was elevated in the enzyme deficient state. By optimizing the feedback, all the impulse responses in the enzyme deficient state recovered to nearly those in the normal physiological state. Similarly, the transient response and the singular value in the enzyme deficient state recovered to nearly the normal physiological values. We elucidated the numerical value of the feedback gain for this optimization. The present analysis is useful for the evaluation of the integrated properties of amino acid metabolism and the optimization technique is potentially of use for determining a treatment course for congenital metabolic enzyme deficiencies.

Amino Acid Metabolism, Inborn Errors↗
PubMed1998

Periodic limb movements and sleep-wake disorder.

The relationship of periodic limb movements (PLM) and sleep-wake disorders in 11 patients was investigated. Two patients complained of insomnia. A patient with cervical spinal canal stenosis had a complaint of difficulty in initiating sleep. Movement index (MI) was 51 and PLM arousal index was 8. A patient with chronic hemodialysis had a complaint of difficulty in initiating and maintaining sleep. MI was 79 and PLM arousal index was 51. One patient with myotonic dystrophy showed 79 in MI and 3 in PLM arousal index. It is suspected that myotonic dystrophy is less sensitive to stimuli during sleep (i.e. PLM). These results suggest that the sleep-wake disorders associated with PLM relate to the threshold of awakening.

Adult↗
PubMed1998

[Periodic limb movement disorder].

The periodic limb movements (PLM) are defined as stereotyped, periodic movements of the legs and/or upper limbs during sleep. The patient exhibits dorsifilexion of the ankle and extension of the big toe with occasional flexion of the knee and hip. PLM originally was described as "nocturnal myoclonus" by Symonds in 1953. Recently, the term "nocturnal myoclonus" has been replaced with PLM, because the movements are slower than true myoclonic movement. The appearance of PLM was reported in sleep apnea syndrome, delayed sleep phase syndrome, narcolepsy, spinal cord tumor, diabetes mellitus and uremia. The prevalence of PLM statistically increase with age. Patients with PLM show excessive daytime sleepiness or insomnia. Several reports show the difficulty recognizing periodic limb movement disorder (PLMD) without polysomnography (PSG). The diagnosis of PLMD is established only by PSG.

Anticonvulsants↗
PubMed1998

[Inter-institute variations in International Normalized Ratio and thrombotest].

Oral anticoagulant therapy is effective for reducing the risk of thromboembolic events in patients with atrial fibrillation or other heart diseases. However, the intensity of oral anticoagulation therapy required in high risk patients, especially in Japanese patients, to achieve the best balance between the prevention of thromboembolic events and bleeding complications remains unclear. The multicenter study of Toyama Warfarin Rational Dosage (TOWARD) was started in 1996 to determine the optimal level of anticoagulant therapy. This study investigated the relationship between values of thrombotest (TT) and International Normalized Ratio (INR) measured from the same samples to clarify inter-institute variations. The relationship between TT and INR was not linear but hyperbolic. Changes of INR to TT are relatively small in the TT range of more than 20% as compared with the range of 20% or less. There were considerable inter-institute variations of TT, and the coefficient of variation (CV) was 0.16 and 0.24 in the low level and high level anticoagulation samples, respectively. However, the variations became significantly small when the same reference was used. The CV of INR was 0.12 and 0.08 in the high level and low level anticoagulation samples, respectively, and very similar with the control samples without anticoagulation (0.11). The variation was small when INR was obtained from the international sensitivity index (ISI) of thromboplastin less than 1.5. TT is widely used for monitoring oral anticoagulant therapy in Japan, and is an excellent system with little inter-institute variation when a standard reference is offered. Since INR has been established as an international monitoring system, the use of INR measured with thromboplastin of small ISI is recommended for monitoring.

Anticoagulants↗
PubMed1998

[Treatment with beta-blockers in patients with acute coronary syndrome].

The effects of beta-blockers on acute myocardial infarction can be divided into those that are immediate and long-term (secondary prevention). beta-blockers given early in the course of infarction may diminish myocardial oxygen demand and therefore reduce chest pain and infarct size. Many clinical trials have clearly shown that both early and long-term treatment with beta-blockers reduce cardiac mortality and the rate of re-infarction. As seen in recommendations of ACC (American College of Cardiology)/AHA (American Heart Association) guidelines for management of acute myocardial infarction, all patients without a contraindication to beta-blockers should be treated with beta-blockers from very early course of the onset and be continued indefinitely.

Acute Disease↗