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Biomedical subjects

H Suzumura

Publications and source records attributed to H Suzumura.

At least 19 recordsLinked to original sources
PubMed2005

Effects of shift schedules on fatigue and physiological functions among firefighters during night duty.

To examine the effects of shift schedules on fatigue and physiological functions among firefighters a 17-day field study at a fire station was carried out. Eleven firefighters, who were engaged in firefighting emergency services, participated in this study. At the fire station, night duty (22:00-07:00) was divided into 5 periods (P1: 22:00-00:00; P2: 23:45-01:45; P3: 01:30-03:30; P4: 03:15-05:15; P5: 05:00-07:00). The participants were assigned to one of these 5 periods and awakened to answer calls from the city's central information centre. They took naps in individual rooms during night duty, except when on night shift or when called out on an emergency. Subjective complaints of fatigue, critical flicker fusion frequencies, 3-choice reaction times, and oral temperature were measured before and after work and following breaks during their 24 working hours. Heart rate variability was also recorded to evaluate autonomic nerve activity. The results show that during P3 and P4, participants who had to wake up at midnight took shorter naps. The rates of subjective complaints regarding P3 and P4 tended to be higher than those for P1, P2, and P5. The ratios of the low frequency component of heart rate variability to the high frequency component during P4 were significantly lower than those during P5. It is assumed that such an irregular sleeping pattern causes many complaints of subjective fatigue, and adversely affects physiological functions. A night-duty shift schedule ensuring undisturbed naps should be considered.

Adult↗
PubMed2003

Neonatal intractable atrial flutter successfully treated with intravenous flecainide.

We present a neonatal case with intractable atrial flutter that did not respond to digitalization and electrical cardioversion. Intravenous flecainide administration completely resolved the atrial flutter. Proarrhythmic effects were not induced by flecainide administration. Although the efficacy of flecainide for atrial flutter during the infantile or childhood period is low, intravenous flecainide is worth consideration as a treatment for atrial flutter, even in intractable cases as described here, during the neonatal period.

Anti-Arrhythmia Agents↗
PubMed2001

Effect of carvedilol on atrioventricular conduction in the ischemic heart.

We compared the effects of carvedilol on atrial-His and His-ventricular conduction with those of propranolol in isolated rat hearts. Hearts were perfused retrograde, and atrial-His and His-ventricular intervals were measured. The effective doses that increased conduction times by 25% were 10(-6) M for atrial-His and 3x10(-6) M for His-ventricular for propranolol, and 8x10(-8) M for atrial-His and 10(-8) M for His-ventricular for carvedilol. Prazosin did not affect the atrial-His and His-ventricular intervals. After ischemia-reperfusion, atrial-His and His-ventricular intervals increased to a greater extent with 10(-6) M carvedilol. To determine the direct membrane effect, we examined the transmembrane action potential in guinea pig papillary muscle. Both drugs decreased the maximum upstroke velocity equally. Our data indicate that carvedilol had a greater effect on atrioventricular conduction in the setting of ischemia-reperfusion than did propranolol. This effect of carvedilol was not due to its alpha-adrenoceptor blocking property or to a direct membrane effect.

Action Potentials↗
PubMed2001

Diastolic flow velocity of the left pulmonary artery of patent ductus arteriosus in preterm infants.

BACKGROUND: The usefulness of diastolic pulmonary flow velocity determined by echocardiography in the assessment of symptomatic patent ductus arteriosus (sPDA) in preterm infants has not been confirmed. METHODS: Echocardiography was performed daily in infants ranging from 23 to 31 gestational weeks of age, and diastolic flow velocity of the left pulmonary artery (DFLPA) was measured. The DFLPA data before indomethacin administration for sPDA were compared with data obtained after indomethacin administration. The normal range of DFLPA was also determined from serial measurements performed in infants who did not develop sPDA during the first 7 days of life. Then, this range was compared with data from infants who did develop sPDA during this time. RESULTS: In infants who underwent indomethacin treatment, DFLPA increased with the development of sPDA and decreased when the symptoms of sPDA disappeared. On the basis of results from serial DFLPA measurement, the sensitivity and specificity of DFLPA for assessing sPDA was found to be 0.82 and 0.83, respectively. CONCLUSIONS: Measurement of DFLPA by echocardiography is a useful method for assessing sPDA in preterm infants.

Blood Flow Velocity↗
PubMed2000

Role of infection in the development of acquired subglottic stenosis in neonates with prolonged intubation.

OBJECTIVE: To examine whether clinically diagnosed infection correlates with subsequent development of subglottic stenosis in intubated neonates. METHODS: Sixty-two neonatal infants intubated for more than 14 days were examined. Several risk factors for subglottic stenosis, including infection, duration of intubation, frequency of intubation, the size of the endotracheal tube etc., were evaluated by multiple logistic regression analysis. RESULTS: Infection that occurred within 14 days of intubation showed a positive correlation with subsequent subglottic stenosis. The duration of intubation, frequency of intubation and the size of the endotracheal tube did not affect the development of subglottic stenosis. The majority of infections were considered to be respiratory tract infections, including pneumonia. CONCLUSIONS: Infection occurring within 14 days of intubation is considered to be a risk factor for acquired subglottic stenosis in neonates intubated for more than 14 days. Prevention of infection within 14 days of intubation may reduce the incidence of subglottic stenosis in neonates.

Gestational Age↗
PubMed2000

Development of non-bacterial thrombotic endocarditis after percutaneous transvenous mitral commissurotomy for severely calcified mitral stenosis.

We encountered a case of mitral stenosis, complicated with non-bacterial thrombotic endocarditis, that developed after percutaneous transvenous mitral commissurotomy (PTMC). A 71-year-old female Japanese patient had severe congestive heart failure and underwent PTMC for critical and severely calcified mitral stenosis. Four weeks later, the echocardiogram demonstrated a highly echoic protrusion in the postero-medial commissure of the mitral valve. There was little evidence of inflammation at that time. She had been anticoagulated adequately since she was admitted. The patient underwent replacement of the mitral valve. She did not show any evidence of systemic embolization. Microscopic evaluation showed only organized thrombus but no evidence of inflammation in the mitral valve. Silent development of non-bacterial thrombotic endocarditis after PTMC should be recognized as a rare but potentially lethal complication of PTMC.

Aged↗
PubMed1999

Increased hyperkinesis in noninfarcted areas during short-term follow-up in patients with first anterior acute myocardial infarction treated by direct percutaneous transluminal coronary angioplasty.

The time course and clinical significance of hyperkinetic wall motion (HWM) in a noninfarcted area in direct percutaneous transluminal coronary angioplasty (PTCA) has not been clearly demonstrated in patients with acute myocardial infarction (AMI). The objectives of this study were to examine the change in HWM during one-month follow-up after direct PTCA and determine its impact on the recovery of global left ventricular function. A total of 61 patients with first anteroseptal AMI and one vessel disease were evaluated. The paired left ventriculograms in the 30 degrees right anterior oblique view taken both at baseline and follow-up were analyzed by the centerline and area length methods. The severity of hypokinesis was expressed by mean regional wall motion (standard deviation/chord) in most hypocontractile 50% of chords respondable to left anterior descending coronary artery area and HWM by mean regional wall motion in most hypercontractile 50% of chords of noninfarcted area. HWM increased from 0.18 +/- 1.07 to 0.48 +/- 1.30 (p = 0.0608). The delta global ejection fraction (global ejection fraction at follow-up minus global ejection fraction at baseline) was correlated with both delta infarcted wall motion (infarcted wall motion at follow-up minus infarcted wall motion at baseline) and delta HWM (HWM at follow-up minus HWM at baseline) (r = 0.576, p < 0.0001, r= 0.383, p = 0.0036, respectively) during follow-up. Further, the delta global ejection fraction showed better correlation with delta (HWM + infarcted wall motion) [(HWM plus infarcted wall motion at follow-up) minus (HWM plus infarcted wall motion at baseline)] (r= 0.593, p < 0.0001). Direct PTCA resulted in the enhancement of HWVM, which contributed to the increase in the global ejection fraction with the recovery of infarcted wall motion.

Aged↗
PubMed1999

[Neonatal transient hypothyroidism].

Neonatal screening for congenital hypothyroidism can detect permanent and transient hypothyroidism. The latter condition is called neonatal transient hypothyroidism. This may result from various causes, but, especially, it should be suspected whenever there is a history of maternal autoimmune thyroid disease, including Hashimoto thyroiditis, Graves disease, hypothyroidism on replacement therapy, or recurrent congenital hypothyroidism of a transient nature in subsequent siblings. Transplacental TSH-receptor antibodies may affect fetal or neonatal thyroid function. Although thyroid dysfunction may be transitory, long-term follow-up is desirable.

Congenital Hypothyroidism↗
PubMed1999

Evaluation of adjunctive intracoronary administration of acetylcholine following intravenous infusion of ergonovine to provoke coronary artery spasm.

A dilemma arises in patients with chest pain or other symptoms suggestive of coronary artery disease but without significant coronary artery stenosis or spasm even after the spasm provocation test by either ergonovine or acetylcholine. Incremental doses of intracoronary acetylcholine (up to 100 micrograms for left coronary artery and 50 micrograms for right coronary artery) were administered when intravenous infusion of ergonovine 0.4 mg showed negative results. A total of 39 patients were studied. Provocation test was performed because of chest pain suggestive of coronary artery disease (n = 19), atypical chest pain (n = 6), post balloon angioplasty status (n = 6), silent ischemia (n = 4), Adams-Stokes syndrome (n = 3), and dead-on-arrival (n = 1). Characteristics of chest pain indicated variant angina (n = 11), rest angina (n = 4), and effort angina (n = 4). No electrocardiographic evidence of ischemia was detected before this test in any patient. Spasm was induced in 23 patients (59.0%) with complete obstruction in 7 (30.4%), diffuse vasoconstriction (90-99%) in 14 (60.9%), and focal spasm in 2 (8.7%). The patients with chest pain showed the highest positive rate of 78.9%. Further, the patients with atypical chest pain and miscellaneous reasons also revealed positive rates of 33.3% and 42.9%, respectively. One ventricular tachycardia and 2 atrial fibrillations occurred but terminated spontaneously. This test is useful for detecting spasm in a variety of patients in whom intravenous ergonovine infusion fails to induce spasm.

Acetylcholine↗
PubMed1998

[Significance of measuring urinary 17-ketosteroid sulfates at the work-place].

We examined availability of urinary 17-KS-S to evaluate work and job strain by presented the results in two field research and one experiment. It became clear that urinary S/OH was a comprehensive parameter of thermal strain, under the combined load condition of temperature and exercise, and as an additional factor, under the various load conditions of air velocity. Significant changes of urinary S/OH before and after the rest break and holiday suggested that the findings reflected fatigue conditions. This suggestion was strongly supported by the finding that the values of urinary S/OH on the first day-off after a mid-night shift and those 1 to 3 days later were not able to recover to the value before the night shift. A ratio between urinary 17-KS-S and 17-OHCS, S/OH, suggests a method of evaluating the degree of strain and the condition of fatigue and over-fatigue by measuring these parameters and thus clarifying the work conditions and work-place environment.

17-Hydroxycorticosteroids↗
PubMed1996

Coffin-Siris syndrome: a case of an extremely low birthweight infant with severe kyphoscoliosis.

A case of Coffin-Siris syndrome in a male of extremely low birthweight with severe kyphoscoliosis is reported. His birthweight was 965 g, the lowest reported in the world for an infant with this syndrome. Coffin-Siris syndrome is characterized by nail hypoplasia of the fingers and toes, eyebrow hypertrichosis, prominent lips and prenatal or postnatal growth retardation. He was the only case who was mechanically ventilated from birth because of birth asphyxia. He died at 12 days of age because of sepsis, a poor immune system as in other extremely low birthweight infants, and because he easily suffered from upper respiratory infection as a result of Coffin-Siris syndrome. Kyphoscoliosis is suggested as one of the important features in low birthweight cases of Coffin-Siris syndrome in previous reports and in the present case.

Abnormalities, Multiple↗
PubMed1996

Chronic respiratory failure after acquired cytomegalovirus infection in a very low birthweight infant.

The case of a female infant who developed chronic respiratory failure after an acquired cytomegalovirus (CMV) infection is presented here. She was a very low birthweight (VLBW) infant and was free from oxygen supplement until 2 months after birth. Interstitial pneumonia occurred at 2 months of age, and her respiratory condition gradually deteriorated. A chest roentgenogram at 4 months revealed hyperinflation and reticular shadow, similar to that of severe chronic lung disease (CLD) in preterm infants. She was mechanically ventilated because of progressive respiratory deterioration, and oxygen dependency continued for 5 months after extubation. There are several previous reports of CMV pneumonia in term neonates or infants. However, there appears to be no published report on the pulmonary sequelae of CMV pneumonia in VLBW infants. The present case seems to indicate that acquired CMV pneumonia in VLBW infants causes chronic respiratory failure even when mechanical ventilation is not administered, and this respiratory failure is very similar to CLD in clinical symptoms and chest roentgenogram.

Chronic Disease↗
PubMed1994

Quantitation and immunocytological identification of interleukin-1 in nasal polyps from patients with chronic sinusitis.

Immunoreactive interleukin-1 (IL-1) alpha and beta levels in nasal polyp (NP) extracts were measured from 22 adult patients with chronic sinusitis (CS) in order to determine their significance in the pathogenesis of NP. The NP sample was separated into mononuclear and polymorphonuclear fractions. In the mononuclear fraction, the mean value of IL-1 beta was 21.5 pg/ml/g, which was significantly higher than that of IL-1 alpha (8.4 pg/ml/g, p < 0.01). In younger adults, the IL-1 alpha and IL-1 beta levels were 21.2 and 59.4 pg/ml/g, which were significantly higher than those in older CS patients (p < 0.01). There was a significant reverse correlation between patient's age and IL-1 beta levels in the mononuclear fraction (r = -0.509, p < 0.01). Immunoreactive IL-1, mainly IL-1 beta, was identified in the cytoplasmic area of monocytes. A certain amount of immunoreactive IL-1 is produced in mononuclear leukocytes, particularly activated monocytes, and IL-1 beta production is greater than IL-1 alpha. In younger adult CS patients, NPs contain larger amounts of IL-1 beta in monocytes, compared to those of older patients.

Adolescent↗