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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 127 records · Page 7Linked to original sources

Is the QT interval an indicator of autonomic state?

Prolonged QT interval is suggested to indicate an increased risk of sudden cardiac death in certain clinical conditions such as diabetes mellitus. We investigated whether the individual QT interval is an indicator of an autonomic state. An ambulatory 24-hour ECG was recorded in 53 subjects from different clinical backgrounds. Power spectral components of heart rate variability (HRV) and the QT interval were regressively obtained at a heart rate of 60, 70, 80, 90, or 100 beats per minutes (bpm). Log values of the high-frequency component of HRV (HF: 0.15-0.50 Hz, a scale of cardiac parasympathetic tone) failed to show a relationship with the QT interval. In contrast, the QT interval at a heart rate of 90 bpm and 100 bpm showed a significant correlation with the log values of the low-frequency component (LF: 0.04-0.15 Hz) and the log[LF/HF], i.e., a putative scale of sympathetic tone (100 bpm: QT vs logLF: r = 0.414, p < 0.005, QT vs log[LF/HF]: 0.416, p < 0.002). Also, attenuated rate-dependent QT shortening was associated with greater logLF and log[LF / HF] values at a heart rate of 80, 90, or 100 bpm. These results suggest that the QT interval at a moderate heart rate (approximately 90-100 / min) and the degree of rate-dependent QT shortening are related to individual sympathetic tone.

Autonomic Nervous System↗

[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↗

[Molecular biological analysis of retinal and streptococcal heat-shock protein 60].

PURPOSE: The observation of recurrent oral aphtha preceding ocular inflammation in patients with Behçet's disease suggests a role of oral Streptococcus in the etiology of this disease. Heat-treated Streptococcus antigen can induce ocular inflammation or systemic symptoms in Behçet's disease patients. Furthermore, the presence of an autoantibody against retinal heat-shock protein 60 (HSP 60) has been detected in the sera of these patients. Injection of extracted retinal HSP 60 also induces experimental uveitis in treated rats. The characteristics of retinal HSP 60 and HSP 60 from S. pyogenes were evaluated using a molecular biological approach. METHODS: The gene encoding HSP 60 was isolated by polymerase chain reaction (PCR) from a bovine retinal cDNA library and from S. pyogenes DNA. The DNA sequence of the HSP 60 coding region was determined, and the amino acid sequences of the encoded proteins were predicted from the DNA sequence. The synthetic peptide (50 nmol) was emulsified with Freund's complete adjuvant and injected into rats. RESULTS: Comparison of the amino acid sequences of Streptococcal and bovine retinal HSP 60 revealed about 200 residue regions with 47% homology. Experimental uveitis was mainly induced in rats inoculated with retinal HSP 60-derived peptide or Streptococcus HSP 60-derived peptide that is equivalent to residues 245-259 of human HSP 65. DISCUSSION: The retinal and Streptococcal HSP 60 amino acid composition is thought to be important and useful for investigating the mechanisms involved in the induction of Behçet's disease.

Animals↗

[Apical hypertrophic cardiomyopathy].

Clinical and laboratory data of apical hypertrophic cardiomyopathy were reviewed based on our own experience of 120 consecutive patients, emphasizing various electrocardiographic characteristics including their natural course and the diagnostic capability of nuclear magnetic resonance imaging(MRI). This peculiar disease entity was mainly detected by annual health check and characterized by giant negative T waves(-1.2(-)-4.0 mV) in the middle-aged men. Transition from normal T wave to the inversion required several years and then usually unchanged, and may disappear within several years in occasional case, in which apical aneurysm was developed. The prognosis was generally good, but atrial fibrillation caused heart failure in 4 cases. MRI was conclusive to identify the diversity of muscular hypertrophy, and it was much more diagnostic than left ventriculography, because it was capable to obtain the exact short-axis view of many sections in addition to the long-axis view. Another look including echocardiography, ultrafast computed tomography, therapy and natural history was concisely reviewed.

Cardiomyopathy, Hypertrophic↗

[Sphincter-preserving surgery for lower rectal cancer aimed at improving postoperative bowel function].

Much attention has been focused on sphincter-preserving surgery for patients with lower rectal cancer, leading to renewed interest in the outcome of postoperative bowel function. Some patients who undergo sphincter-preserving surgery experience bowel dysfunction, such as frequent stools, severe constipation, soiling, and incontinence. These symptoms were thought to be correlate with lower resting pressure, lower rectal compliance, sensory disturbance of the anal canal, spasm, and delayed transit in the colon above the anastomosis. To improve postoperative bowel function, reconstruction with the colonic J-pouch has been performed, which results in a satisfactory functional outcome. About 80% of patients with a J-pouch were able to tolerate over 10 minutes after feeling the desire to defecate. An anorectal manometric study showed no abnormal spastic movement of the neorectum and a transit study showed that the J-pouch group was superior to the straight group with respect to the smoothness of movement of radiopaque markers from the cecum to anal ring, although a small number of markers were retained in the colonic J-pouch. Patients who received a colonic J-pouch had fewer defecation problems in daily life. Further study is need to improve postoperative bowel movement in patients who undergo sphincter-preserving surgery.

Anal Canal↗

[A case of large-cell lung cancer responding remarkably to combination chemotherapy with vinorelbine, mitomycin C and carboplatin].

The patient was a male who started to show symptoms at age 59. He was a smoker until age 40. In October 1998 he came to the hospital complaining of hemosputum and hoarseness. There was already swelling of the supraclavicular lymph nodes. Through lymph node aspiration cytology and bronchofiberscopy, large-cell carcinoma (T2N3M0, stage IIIB) was diagnosed. Chemotherapy with vindesine (VDS, 3 mg/m2), mitomycin C (MMC, 8 mg/m2) and carboplatin (CBDCA, 300 mg/m2) was conducted in three stages. Thanks to a partial response (PR) the patient was released in January 1999. However, in September 1999 he was readmitted when dysphagia, loss of body weight and dyspnea appeared. After bronchoscopy, chemotherapy combining vinorelbine (VNB, 25 mg/m2), (MMC, 8 mg/m2), CBDCA and the Calbert method calculated at AUC = 4.5 (AUC = area under the concentration-time curve) was completed in 4 stages. Upon PR and an abatement of symptoms he was released from the hospital. It is thought that treatment combining VNB is effective.

Antineoplastic Combined Chemotherapy Protocols↗

[Pneumocystis carinii pneumonia associated with acquired immunodeficiency syndrome followed by KL-6, surfactant protein-D and beta-D-glucan in serum].

A 40-year-old man was admitted to our hospital with acute respiratory failure. The patient was given a diagnosis of Pneumocystis carinii pneumonia (PCP) associated with acquired immunodeficiency syndrome (AIDS). After treatment with trimethoprim-sulfamethoxazole and corticosteroid, the respiratory failure was improved and the abnormal shadows disappeared. The serum beta-D-glucan level, significantly elevated (76.0 pg/ml) on admission, returned to the normal range within two weeks. Serum KL-6 (max. 7580 U/ml) and surfactant protein-D (SP-D) (max. 235 ng/ml), which are produced by type II pneumocytes, increased after elevation of the beta-D-glucan level and decreased gradually following successful treatment. These findings suggest that beta-D-glucan may be a serological marker for PCP infection and KL-6 may be a serological marker for lung injury in PCP with AIDS.

AIDS-Related Opportunistic Infections↗

[Respiratory failure due to diaphragmatic dysfunction in Charcot-Marie-Tooth disease: a case report].

A 56-year-woman with type 2 respiratory failure due to diaphragmatic dysfunction in Charcot-Marie-Tooth disease (CMT) is reported. The patient, who had a 50-year history of CMT, was referred to our hospital because of nocturnal dyspnea. Arterial blood gas analysis on admission showed marked hypoxia with hypercapnia, and physical examination revealed thoracoabdominal paradoxus in the supine position. Chest radiography revealed elevation of both sides of the diaphragm. The vital capacity and arterial blood gas pressure in the sitting position were markedly higher than those in the supine position. Electrical phrenic nerve stimulation failed to produce any convincing muscle action potential in the diaphragm. These findings suggested that her respiratory failure was induced by both diaphragmatic dysfunction caused by bilateral phrenic nerve palsy due to CMT. Treatment of this patient was started at home with a pressure support ventilator, resulting in satisfactory clinical improvement. In general, respiratory muscle impairment is a rare phenomenon in a patient with CMT. However when a patient with CMT complains of dyspnea or if unexpected heart failure develops, it is important to keep in mind that CMT may be associated with phrenic nerve palsy.

Charcot-Marie-Tooth Disease↗

[Usefulness of washout rate analysis in adenosine triphosphate-stress thallium-201 myocardial scintigraphy in patients with vasospastic angina].

OBJECTIVES: This study evaluated the usefulness of washout rate analysis in adenosine triphosphate(ATP) stress thallium-201 scintigraphy for the diagnosis of vasospastic angina. METHODS: This study included 76 patients with vasospastic angina and 18 normal controls undergoing coronary arteriography. If significant coronary artery stenosis (> or = 50%) was pointed out, the subject was excluded from this study. 111 MBq of thallium-201 was intravenously injected 3 min after ATP loading (0.16 mg/kg/min) was started. Single photon emission computed tomography (SPECT) was performed 10 min and 4 hr after intravenous injection of ATP. The mean washout rate (%) was calculated based on a bull's eye map and was divided into 3 regions, the antero-septal/lateral/inferior regions. The washout rate in each region was calculated. Regional uptake was visually estimated based on the 17 segments of SPECT images. RESULTS: The washout rate in the normal control group was 48.9 +/- 4.1 (mean +/- SD)%. In patients with vasospastic angina, the washout rate in areas with coronary vasospasm was 33.4 +/- 5.5%. This value was significantly lower than in the areas without coronary vasospasm (42.8 +/- 3.6%). The usefulness of washout rate analysis in the diagnosis of vasospastic angina with a cut-off value of less than -2SD from normal washout rate in the 3 regions was examined. A significantly higher diagnostic value was found by washout rate analysis (sensitivity 72.3%, specificity 79.7%, and accuracy 74.6%) compared with visual evaluation of early images (sensitivity 50.3%, specificity 73.9%, and accuracy 57.5%). CONCLUSIONS: The diagnostic value of washout rate analysis was significantly higher (73.1%) compared with visual evaluation of early images (50.3%) in patients with multivessel vasospastic angina.

Adenosine Triphosphate↗

[Occupational health services to assist workers' health promotion based on a participatory training program of staff members for public health centers].

Work-related health problems among employees of small-scale enterprises and un-employed workers are still serious in Japan. Occupational health services related to their working conditions and environment are limited and more provison needs to be made. Our participatory training program is aimed at allowing staff members of public health centers to provide occupational health services and assist workers' health promotion. In this program, participants examine occupational risk factors affecting workers' health problems with ergonomic check-lists and discuss potential improvements in the workplace. Participants experience practical visits to small-scale enterprises in their communities and the resultant occupational health services are discussed and evaluated at the final step in this program. The essential feature of successful case was that the public health center had coordinated community resources and occupational health services with ergonomic check-lists accepted by small-scale enterprises. This participatory training program is effective from the viewpoint of evaluating occupational risk factors affecting workers' health problems and proposing improvements in the workplace. In order to optimally provide occupational health services for the employees of small-scale enterprises and un-employed workers, the community resources including health facilities and the parties concerned must be organized and utilized effectively.

Education↗

Tissue distribution of cadmium in rats given minimum amounts of cadmium-polluted rice or cadmium chloride for 8 months.

To investigate the relationship between cadmium (Cd) toxicity, intestinal absorption, and its distribution to various tissues in rats treated orally with minimum amounts of Cd, 14 female rats per dose group per time point were given diets consisting of 28% purified diet and 72% ordinary rice containing Cd-polluted rice (0. 02, 0.04, 0.12, or 1.01 ppm of Cd) or CdCl(2) (5.08, 19.8, or 40.0 ppm of Cd) for up to 8 months. At 1, 4, and 8 months after the commencement of Cd treatment, seven rats per group were euthanized for pathological examinations to determine the Cd concentrations in the liver and kidneys and metallothionein (MT) in the liver, kidneys, intestinal mucosa, serum, and urine. One week before each period of 1, 4, and 8 months, the remaining seven rats in each group were administered a single dosage of (109)Cd, a tracer, to match the amounts of the designated Cd doses (about 1.2 to 2400 microg/kg body wt). They were euthanized 5 days later to determine the distribution of Cd to various tissues. No Cd-related toxic changes were observed. The concentrations of Cd in the liver and kidneys at any time point and MT in the liver, kidney, serum, and urine at 4 and 8 months increased dose-dependently, whereas MT in the intestinal mucosa did not alter markedly at any time point. The distribution rates of Cd to the liver increased dose-dependently (40% at lower doses to 60% at higher doses), whereas those to the kidney decreased dose-dependently (20% at lower doses to 10% at higher doses). The Cd retention rates 5 days after (109)Cd administration (amounts of Cd in various tissues/amounts of Cd administered) ranged from 0.2 to 1. 0% at any time point. These results suggest that the distribution of Cd to the liver and kidneys after the oral administration vary depending on the dosage levels of Cd. The difference of the distribution pattern of Cd to the liver and kidney is probably due to the difference in the form of the absorbed Cd, i.e., free ion or Cd-MT complex, although not closely related to the MT in the intestinal mucosa.

Administration, Oral↗

A scheme for challenging cholesteatoma in children.

In order to secure both long-lasting carefree ears and hearing-preservation/restoration, the best method to apply is the closed-method tympanoplasty, especially for cholesteatomatous otitis media in children. We agree with this method, in spite of the high percentages of postoperative residual cholesteatoma in children. Until a better way of irradicating cholesteatoma becomes available, either staged operations or periodical check-ups for many years are mandatory. While postoperative attic retraction/cholesteatoma formation seems to be preventable in most cases, the rate of residual cholesteatoma is very high in our data and in other reports. Looking for a reason, the differences between the cholesteatoma in children and those in adults are to be investigated in macro-, micro- and ultramicroscopic observations. In addition, basic rather than clinical studies on cholesteatoma in children are requested.

Child↗

Strain- and age-dependent loss of sarcoglycan complex in cardiomyopathic hamster hearts and its re-expression by delta-sarcoglycan gene transfer in vivo.

The delta-sarcoglycan (SG) gene is deleted in hamsters with hereditary cardiomyopathies. Immunological analyses of heart before, but not after, the progression of cardiomyopathy (CM) revealed that the BIO 14.6 strain, a model of hypertrophic CM, heterogeneously preserved alpha- and gamma-SG with loss of beta- and delta-SG. In contrast, the TO-2 strain, a model of dilated CM, did not show either SG. Furthermore, in vivo transfer of the full length delta-SG gene to TO-2 hearts expressed all four SGs. Thus, this age- and strain-dependent features suggest a more feasible setting for TO-2 than BIO 14.6 to verify both CM progression and the efficacy of gene therapy.

Age Factors↗

Differential expression of alpha 1, alpha 3 and alpha 5 integrin subunits in acute and chronic stages of myocardial infarction in rats.

OBJECTIVE: Anchoring cardiac myocytes to extracellular matrix, which is mediated mainly by integrins on their surfaces, is important for maintaining the architecture of myocardial tissues and transmitting mechanical force. We evaluated the expression of alpha integrin subunits on myocytes and the accumulation of interstitial collagen and fibronectin at acute and chronic stages after myocardial infarction. METHODS: Myocardial infarction was induced by ligation of left coronary arteries in rats. The expression of alpha 1, alpha 3 and alpha 5 integrin subunits, and accumulation of collagen and fibronectin were analyzed with immunohistochemistry or sirius-red staining. RESULTS: In hearts without infarction, moderate expression of the alpha 3 subunit and only slight expression of the alpha 5 subunit were observed on myocytes. In the first week after infarction, the alpha 1 subunit, collagen and fibronectin were increased only in the peri-infarcted area, while the alpha 5 subunit was increased both in peri-infarcted and non-infarcted areas. At day 42, the expression of the alpha 1 subunit and collagen were still increased, although the alpha 5 subunit and fibronectin were decreased. The expression of the alpha 3 subunit was not altered throughout the experimental period. CONCLUSION: These data suggest that integrin subunits play an important role in healing and remodeling processes after myocardial infarction.

Animals↗

Troglitazone inhibits voltage-dependent calcium currents in guinea pig cardiac myocytes.

BACKGROUND: It has been suggested that intracellular Ca2+ overload in cardiac myocytes leads to the development of diabetic cardiomyopathy. Troglitazone, an insulin-sensitizing agent, is a promising therapeutic agent for diabetes and has been shown to prevent diabetes-induced myocardial changes. To elucidate the underlying mechanism of troglitazone action on cardiac myocytes, the effects of troglitazone on voltage-dependent Ca2+ currents were examined and compared with classic Ca2+ antagonists (verapamil and nifedipine). METHODS AND RESULTS: Whole-cell voltage-clamp techniques were applied in single guinea pig atrial myocytes. Under control conditions with CsCl internal solution, the voltage-dependent Ca2+ currents consisted of both T-type (ICa,T) and L-type (ICa,L) Ca2+ currents. Troglitazone effectively reduced the amplitude of ICa,L in a concentration-dependent manner. Troglitazone also suppressed ICa,T, but the effect of troglitazone on ICa,T was less potent than that on ICa,L. The current-voltage relationships for ICa,L and the reversal potential for ICa,L were not altered by troglitazone. The half-maximal inhibitory concentration of troglitazone on ICa,L measured at a holding potential of -40 mV was 6.3 micromol/L, and 30 micromol/L troglitazone almost completely inhibited ICa,L. Troglitazone 10 micromol/L did not affect the time courses for inactivation of ICa,L and inhibited ICa,L mainly in a use-independent fashion, without shifting the voltage-dependency of inactivation. This effect was different from those of verapamil and nifedipine. Troglitazone also reduced isoproterenol- or cAMP-enhanced ICa,L. CONCLUSIONS: These results demonstrate that troglitazone inhibits voltage-dependent Ca2+ currents (T-type and L-type) and then antagonizes the effects of isoproterenol in cardiac myocytes, thus possibly playing a role in preventing diabetes-induced intracellular Ca2+ overload and subsequent myocardial changes.

Animals↗

Comparison of pathogenic factors expressed by group A Streptococci isolated from patients with streptococcal toxic shock syndrome and scarlet fever.

Streptococcal toxic shock syndrome (STSS) is an illness with high mortality. To obtain clues to understanding the pathogenesis of STSS, we investigated the expression of several pathogenic factors in ten group A streptococcus (GAS) isolates from ten patients with STSS in Japan, in comparison with ten GAS isolates from children with scarlet fever. The ten scarlet fever-derived GAS isolates were equally low in lethality and anti-phagocytic activity in mice and in the production of streptolysin O (SLO), and equally high in production of superantigenic exotoxins (SAGTs) and cysteine proteinase. By comparison, the ten STSS-derived GAS isolates were heterogeneous in the expression of the above pathogenic factors, which ranged from low to high values. Most of the ten STSS-derived isolates were higher in lethality and anti-phagocytic activity and production of SLO, and lower in the production of SAGTs and cysteine proteinase than the ten scarlet fever-derived isolates. The results suggest that the lethality and anti-phagocytic activity examined in mice and SLO may be involved mainly in the development of most of the ten STSS cases.

Animals↗

Improvement of eosinophilic heart disease after steroid therapy: successful demonstration by endomyocardial biopsied specimens.

A 62-year-old man with acute eosinophilic endomyocarditis developed congestive heart failure. The biopsy specimens revealed degranulated eosinophils and eosinophil cationic protein (ECP) in the endocardium, and in activated eosinophils and the myocardial interstitium. On electronmicroscopy, a characteristic cardiac myocytolytic change showing disruption at the intercellular junctional site was observed. After steroid treatment, clinical symptoms, systolic dysfunction and laboratory data dramatically improved. In the subsequent biopsy specimens, eosinophilic infiltration and ECP disappeared. Steroid therapy provided a beneficial effect in preventing the progression of cardiac damage. This effect was clearly documented by histochemical studies of the serial endomyocardial biopsy samples.

Biopsy↗