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Biomedical subjects

S Homma

Publications and source records attributed to S Homma.

At least 127 records · Page 7Linked to original sources
PubMed1997

Electrogastrography after operative repair of esophageal atresia.

Esophageal atresia (EA) is a life-threatening disorder associated with operative complications. Postoperative gastric electrical control activity detected by a non-invasive electrogastrography (EGG) technique was investigated in 13 children aged 1-17 years to clarify whether gastric motility disorders were present. EGG abnormalities were present in 5 patients; persistent dysrhythmias were found in 3. Roentgenographic examinations showed mild gastroesophageal reflux in 3 (60%) of the dysrhythmic patients; 2 others had postprandial dysrhythmias. The mean spectral frequency (MSF) of EA cases with dysrhythmia was significantly higher than that of patients without dysrhythmia in both fasting and postprandial states (P < 0.05). The variability of the peak spectral frequencies (PSFV) in patients with dysrhythmia was significantly higher than in those without dysrhythmia in both fasting and postprandial states (P < 0.05). There were no significant differences in MSF and PSFV between EA patients without dysrhythmia and controls. These results suggest that gastric motor activity may be disordered in patients following operative repair of EA, although they remain asymptomatic. EGG may be a useful screening examination for postoperative gastric functional disorders.

Adolescent↗
PubMed1997

Transesophageal echocardiography-guided transvenous biopsy of a cardiac sarcoma.

Transvenous endomyocardial biopsy is a well established procedure to diagnose rejection after heart transplantation as well as to assess for other cardiomyopathic processes. However, it is rarely used to obtain samples of unidentified cardiac masses. We report a case of a primary cardiac sarcoma in which the histologic diagnosis was provided by transesophageal echocardiography-guided transvenous biopsy. This procedure is accurate and can avoid the potential risk of a diagnostic thoracotomy.

Biopsy↗
PubMed1997

Late pulmonary venous complications after lung transplantation.

Although abnormalities of the pulmonary venous anastomosis in the early postoperative period after lung transplantation have been reported from several centers, late complications related to the pulmonary venous anastomosis have not been described. In the present study, we describe the clinical and transesophageal echocardiographic findings of pulmonary vein anastomotic complications in two patients at 1.9 and 2.3 years after lung transplantation. Both pulmonary venous abnormalities, stenosis in the first instance and thrombosis in the second instance, impaired venous outflow on the affected side causing unilateral edema and pleural effusion. Pulmonary venous abnormalities late after lung transplantation can mimic allograft rejection, opportunistic infection, or heart failure and are best diagnosed by transesophageal echocardiography.

Anastomosis, Surgical↗
PubMed1997

Brachial arterial blood flow during static handgrip exercise of short duration at varying intensities studied by a Doppler ultrasound method.

The purpose of this study was to determine forearm blood flow changes during static handgrip exercise at different intensities in relation to heart rate and blood pressure. Seven active women performed static handgrip exercise at intensities of 10, 30, 50 and 70% maximum voluntary contraction (MVC) in a supine position for 1 min. During exercise at different intensities, the brachial arterial blood flow (Doppler ultrasound method), calculated from vessel diameter, flow velocity and heart rate (measured by ECG), increased to a similar level (137.3 +/- 20.2-160.9 +/- 26.1 mL min-1) from pre-exercise control value (87.5 +/- 14.1 mL min-1). These increases at the lower intensities were attributable to increased in-flow during one cardiac cycle, whereas at the higher intensities, they were due to increased heart rate. Both systolic and diastolic blood pressure (Finapres) changes increased from 10% MVC (16.1 +/- 3.4, 9.0 +/- 1.7 mmHg) up to 50% MVC (33.8 +/- 6.7, 25.0 +/- 4.9 mmHg), but were disproportionately more elevated at 70% MVC (46.1 +/- 7.9, 42.9 +/- 8.9 mmHg), suggesting neural vasoconstriction had occurred. Immediate post-exercise hyperaemia, used as an indicator of poor blood supply, became greater as the exercise intensity increased. These results suggest that the brachial arterial blood flow was maintained at a similar level during 60-s static handgrip exercise at different intensities by elevating the blood pressure and heart rate, which probably counteracted the increased intramuscular pressure and neural vasoconstriction occurring at the higher exercise intensity. The magnitude of the post-exercise hyperemic response increased as exercise level increased despite increased blood-flow to the arm during-exercise. This suggests a worsening imbalance in oxygen delivery in forearm muscles at higher levels of exercise.

Adult↗
PubMed1997

[Clinical and diagnostic characteristics of Legionella pneumonia].

We have characterized clinical and diagnostic features in 18 cases of Legionella pneumonia. Age average of patients was 62.0 years old (male:female = 14:4) and underlying diseases were observed in 12 patients. Legionella pneumonia were diagnosed in 3, 5, 8 and 9 cases by culture, serum antibody measurement, urinary antigen detection and PCR, respectively. Sixteen cases were caused by L. pneumophila, while the other 2 cases were L. bozemanii pneumonia and L. pneumophila or L. dumoffii pneumonia. Chest X-rays of those patients showed multiple pneumonia shadows in 14 cases, alveolar shadows in 10 cases, pleural effusion in 5 cases. Blood-gas analysis on admission indicated hypoxemia in all cases with abnormal A-a DO2. Laboratory findings showed abnormal data in WBC, CRP, LDH, CPK and liver function tests (ex. GOT, GPT) in most cases. Serum antibody testing showed positive by 5 weeks after onset of pneumonia, but 10 cases of Legionella pneumonia diagnosed by other techniques were judged to be negative. In urinary antigen detection test, 6 and 2 cases showed positive 1 and 4 weeks after onset of pneumonia, respectively. Macrolide antibiotics were administered in all cases during the episode, but delay of macrolide administration was observed in 3 of 4 cases of dead outcome. Serum antibody measurement, urinary antigen detection and PCR, in addition to culture to bacteria, may be required for exact diagnosis of Legionella infection.

Adult↗
PubMed1997

Characterizing ventricular mechanics and energetics following repeated coronary microembolization.

Myocardial mechanics and energetics were investigated in an animal model of moderate chronic heart failure (CHF) created by repeated coronary microembolizations in six dogs. The final fractional area change was 34 +/- 4%. Hearts of these animals were isolated and cross-perfused, and balloons were placed in the left ventricle (LV). Chamber contractile state was markedly depressed in embolized hearts as assessed by the slope (Ees 2.74 +/- 0.49 vs. 4.00 +/- 1.18 mmHg/ml, P < 0.01) and volume axis intercept (V: 8.7 +/- 5.9 vs. 1.0 +/- 3.2 ml, P < 0.01) of end-systolic pressure-volume relation compared with a group of six normal dogs. The end-diastolic pressure-volume relation of embolized hearts was shifted to the right, indicating a dilation of the LV. However, systolic and diastolic stress strain relationships were similar in the two groups, suggesting that the average myocardial properties of the embolized hearts are similar to those of normal hearts. The relationship between oxygen consumption and pressure-volume area in embolized hearts had smaller intercept (2.98 +/- 0.44 vs 3.92 +/- 0.39 x 10(-2) ml O2.beat-1.100 g LV-1, P < 0.01) compared with the control group, with no change in the slope. These results contrast with previous findings in pacing CHF and serve as an important characterization of ventricular properties in this model of CHF from different etiology.

Adrenergic beta-Agonists↗
PubMed1997

Exercise-induced changes in beta-adrenergic-receptor mRNA level measured by competitive RT-PCR.

Competitive reverse transcription-polymerase chain reaction (RT-PCR) analysis was used to clarify whether dynamic exercise-induced increases in beta-adrenergic-receptor (beta-AR) number in human lymphocytes are accompanied by increases in the beta-AR mRNA level. Sixteen healthy subjects performed cycle ergometry until exhaustion. Before and immediately after exercise, peripheral blood was drawn from a forearm vein for preparation of lymphocytes. Both the beta-AR mRNA level and the beta-AR number were significantly increased by exercise. The changes in beta-AR mRNA level and beta-AR number were significantly correlated (r = 0.63, P < 0.01). This finding suggests that a rapid increase in beta-AR mRNA level might be an early adaptive response of the sympathetic nervous system to dynamic exercise. In vitro incubation of lymphocytes with epinephrine had no effect on beta-AR mRNA levels, nor did adenosine 3',5'-cyclic monophosphate, protein kinase C, or intracellular Ca2+ increase the beta-AR mRNA level in vitro. Therefore, it appears that other mechanisms underlie the exercise-induced elevation of beta-AR mRNA levels in human lymphocytes.

Adult↗
PubMed1997

Localization of low-KM cAMP phosphodiesterase in rat nephron segments.

To evaluate the roles of cAMP degradation on hormonal actions in the kidney, we examined the segmental distribution and activities of cAMP-phosphodiesterase (PDE), a key enzyme for cAMP hydrolysis, in dissected segments of the rat nephron and characterized the isozyme compositions with subtype-specific inhibitors. Summary of the nephron distribution of PDE activities showed that cAMP-PDE activities were detected in all nephron segments and the distal convoluted tubules (DCTs) had the highest activity. Both in proximal convoluted tubules (PCTs) and medullary collecting ducts (MCDs), more than 80% of the total cAMP-PDE activities were inhibited by a nonspecific PDE inhibitor, 3-isobutyl-1-methylxanthine (IBMX). In PCTs, rolipram (type-IV PDE inhibitor) was an equally potent inhibitor of IBMX, while 8-methoxymethyl-IBMX (MM-IBMX, type-I PDE inhibitor) and cilostamide (type-III PDE inhibitor) inhibited cAMP-PDE by 35 and 57%, respectively. In MCDs, inhibition by rolipram (40%) was less than that by MM-IBMX (70%) or cilostamide (66%). Rolipram potentiated the parathyroid hormone (PTH)-induced cAMP content in PCTs most effectively. Rolipram and MM-IBMX increased the vasopressin (AVP)-stimulated cAMP content equally in MCDs. Cilostamide had no effect on the cAMP content stimulated by PTH or AVP in PCTs and MCDs. These results indicate that PDE activities were unevenly distributed along the rat nephron and cAMP-PDE was composed of at least three isoforms, namely type I, III and IV in PCTs and MCDs. Among these, type-IV PDE was responsible for hydrolysis of cAMP in PCTs, and type-I and IV PDE were responsible for that in MCDs.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1997

Valvular strands and cerebral ischemia. Effect of demographics and strand characteristics.

BACKGROUND AND PURPOSE: Valvular strands, thin filamentous material attached to the mitral or aortic valve, are seen during transesophageal echocardiography and have been associated with stroke. Little is known about this association in different age, sex, and race-ethnic subgroups and the effect of various strand characteristics on this association. METHODS: From patients referred for transesophageal echocardiography, 73 patients with recent ischemic stroke (68) or transient ischemic attack (5) were age matched to 73 stroke- and transient ischemic attack-free control subjects. The association between valvular strands and cerebral ischemia was evaluated for the overall group and demographic subgroups. The effect of strand location, length, number, and valve thickness was also determined. RESULTS: An association between cerebral ischemia and valvular strands was observed (odds ratio [OR] = 4.4; 95% confidence interval [CI] = 2.0 to 9.6). The association was found for both men and women and among all three race-ethnic groups. The OR was greater in those who were younger (12.5 [95% CI = 2.4 to 64.5] for age < 60, 4.8 [95% CI = 1.3 to 18.2] for age 60 to 69, and 1.8 [95% CI = 0.5 to 6.4] for age > or = 70 years). Strands on both the mitral (OR = 3.5; 95% CI = 1.5 to 7.9) and aortic (OR = 3.7; 95% CI = 1.1 to 11.9) valve were associated with cerebral ischemia, whereas the number and length of strands were not. The effect of strands was independent of mitral or aortic valve thickness. CONCLUSIONS: Valvular strands, whether mitral or aortic, are associated with ischemic stroke, especially among younger persons.

Aged↗
PubMed1997

Surgical closure of patent foramen ovale in cryptogenic stroke patients.

BACKGROUND AND PURPOSE: Patents foramen ovale (PFO) is associated with stroke of unknown etiology or cryptogenic stroke. However, optimal treatment to prevent recurrence in cryptogenic stroke patients with PFO is not clearly defined. Since PFO represents a surgically repairable lesion, interest in closing it is high. This report reviews our experience with cryptogenic stroke patients with PFO who underwent surgical PFO closure and were followed for recurrence of neurological events. METHODS: We followed 28 cryptogenic stroke patients (17 men, 11 women; mean age, 41 +/- 13 years) with transesophageal echocardiography-defined PFO who had undergone PFO closure by open thoracatomy. All patients selected for surgery refused, could not take, or failed warfarin therapy. They were followed by physician visits and telephone interviews. RESULTS: There were no surgical complications. With a mean follow-up of 19 months, four patients experienced neurological event recurrence, one stroke, and three transient ischemic attacks. Kaplan-Meier survival analysis demonstrated that the actuarial rate of recurrence was 19.5% (95% confidence limit 2.2-36.8%) at 13 months of follow-up. None of the 17 patients (0%) younger than 45 years suffered a recurrence, whereas four of 11 patients (35%) aged 45 or older experienced a recurrence of neurological event (P < .02). Using a proportional hazards regression model, the increase in relative risk with increasing age was 2.76 per 10 years (95% confidence interval 1.07 to 7.16). CONCLUSIONS: Although PFO is easily repairable in patients with crytogenic stroke, its closure does not consistently prevent recurrence of ischemic events. The recurrence appears to occur more frequently in older cryptogenic stroke patients.

Actuarial Analysis↗
PubMed1997

Subcellular location of polyphenol oxidase in apples.

The location of polyphenol oxidase (PPO) in cells of apple fruit was examined by immunohistochemistry and subcellular fractionation. In mature apple fruits, where vacuoles occupy most of the cells, PPO was detected immunochemically near the cell walls with use of anti-apple PPO antibodies. In cells of immature fruits and tissue culture, PPO was detected in organelles other than the vacuoles, probably in plastids. The plastid fraction was purified by density gradient ultracentrifugation, and the activities of PPO and marker enzymes of plastids were the highest in the plastids. Most apple PPO was in plastids, as are other plant PPOs, and some of the protein was solubilized and proteolyzed during ripening and storage.

Blotting, Western↗
PubMed1997

[Carotid intima-media thickness and the occurrence of plaque in centenarians--data from the Tokyo Centenarian Study].

We studied carotid intima-media thickness at non-plaque sites and the occurrence of plaque in 25 centenarians (8 men and 17 women) living in Tokyo. The studies were done by B-mode ultrasonography and the results were compared with those found in 126 healthy subjects (83 men and 43 women) aged 28 to 82 years. The intima-media complexes were diffusely thickened in the centenarians; average thickness at bifurcations and at three sites in each common carotid artery ranged from 0.91 to 1.12 mm. The thickness was not associated with blood pressure or with serum lipid concentration. The thickness in the control group correlated with age, and that relationship fit a second degree equation. The expected values of mean intima-media thickness of the common carotid arteries at age 100 were computed with these equations; the predicted values ranged from 0.92 to 0.98 mm, which are close to the mean values measured in the centenarians (0.95 to 1.05 mm). However, the variations in intima-media thickness were greater in the centenarians. The prevalence of plaque in the centenarians was 40% for the right carotid artery and 36% for the left, but the prevalence among those in the eighth decade of life was 9.5% for both sides; plaque was not found among subjects in the sixth decade of life or younger. These data suggest that the degree of carotid arteriosclerosis is one factor that limits human longevity.

Adult↗
PubMed1997

[Lipid and lipoprotein profile of Japanese centenarians--high prevalence of hypo beta lipoproteinemia].

To study the relationship between lipids and longevity, we examined the level of serum lipids and apolipoproteins, and the susceptibility of low density lipoprotein (LDL) to oxidation of 45 centenarians (15 men, 30 women, mean age 101.1 +/- 1.4) living in the Tokyo metropolitan area. The average levels of total cholesterol (TC), of LDL-C of high-density lipoprotein cholesterol (HDL-C), and of apolipoproteins A1 and B were significantly lower in centenarians than in healthy middle-aged controls. The frequency of hypobeta-lipoproteinemia (apoB < 60 mg/dl) in centenarians was almost ten times as high as in controls. The time course of copper-mediated LDL, oxidation (assessed by monitoring 234 nm diene absorption (lag time)) did not significantly differ between the two groups. Analysis of LDL subfractions by non-denaturated gradient-gel electrophoresis showed a predominance of large, buoyant LDL particles (pattern A) in 75%, and a predominance of small dense LDL particles (pattern B) in 25% of centenarians. We also assessed activities of daily living (ADL) and cognitive function in the centenarians. Centenarians were divided into two groups according to the median ADL score, and were classified into five groups with a scale clinical dementia. In subjects with good ADL scores, the mean concentration of HDL-3-C was significantly higher than in those with poor ADL scores. Average levels of HDL-C were also significantly lower in subjects with moderate or severe dementia than in those with normal cognitive function. These findings suggest that centenarians have protective phenotypes of lipids and lipoproteins that protect them from atheroscierosis.

Activities of Daily Living↗
PubMed1997

[Tokyo Centenarian Study. 4. Apolipoprotein E phenotype in Japanese centenarians living in the Tokyo Metropolitan area].

To examine the relationship between apolipoprotein E (apoE) phenotype and life span, we measured the frequently of the apoE phenotype and allele in 54 Japanese centenarians who lived in the Tokyo metropolitan area in 1994, 1995, and 1996. The control group consisted of 973 subjects, 883 healthy volunteers who were described previously and 90 healthy people who came to the Keio health consulting center. The apoE phenotypes in the centenarians was 2 E2/E2 (3.7%), 5 E2/E3 (9.3%), 38 E3/E3 (70.4%), and 9 3E/E4 (16.7%). No other phenotype was observed. In the control group, the phenotypes were 2 E2/E2 (0.2%), 57 E2/E3 (5.9%) 712 E3/E3 (73.2%), and 179 E3/E4 (18.4%). The frequency of E2 was higher in the centenarians. The frequencies of the apoE allele in the centenarians and the control subjects were epsilon 2 8.3% vs. 3.5%, epsilon 3 83.3% vs. 85.4%, and epsilon 4 8.3% vs. 10.9%. The frequency of the apoE allele differed significantly between centenarians and control subjects (chi 2 = 6.84, p = 0.033). Levels of serum cholesterol and apolipoprotein B were significantly lower in the E2/E2 + E2/E3 centenarians. Studies of the frequency of the apoE allele in Japanese, French, and Finnish subjects showed that epsilon 2 is more frequent and epsilon 4 is less frequent in centenarians. These data show the apoE phenotype may affect life span: epsilon 2 is positively and epsilon 4 is negatively associated with longevity.

Aged↗
PubMed1997

[Tokyo Centenarian Study. 5. Nutritional status of Japanese centenarians].

To establish the guideline for nutrition in the very old, we analyzed biochemical and hematological data from 45 Japanese centenarians living in Tokyo metropolitan area during 1994 and 1995. Levels of cholesterol, HDL-cholesterol, apolipoprotein A1 and B, albumin, prealbumin in serum were lower than in a control group or lower than the reference range, which indicates that these centenarians were undernourished. RBC counts, hemoglobin, and hematocrit were also low in the centenarians. The concentration of albumin correlated positively with those of HDL-cholesterol and apolipoprotein A1, and negatively with concentration of Lp(a). The value for transferrin correlated positively with energy intake and with the concentration of apolipoprotein A1. The concentration of prealbumin correlated positively with the concentration of hemoglobin, hematocrit and the total cholesterol concentration. According to their nutritional status, the centenarians were divided into 2 groups: well-nourished and undernourished. Those who were well-nourished had higher levels of cholesterol, HDL, Hb, and apolipoprotein A1, their levels of ADL and cognitive function were also high. The findings of blood-chemical data in the centenarians may be partly due to undernutrition. Centenarians who were well-nourished were considered to be aging successfully. These results and others previously published indicate that the concentrations of albumin, prealbumin, transferrin and either CRI or IL-6 are useful for nutritional assessment in the very old.

Aged↗
PubMed1997

[Xanthinuria].

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Humans↗
PubMed1997

Effects of football training on ventilatory and gas exchange kinetics to sinusoidal work load.

The purpose of this study was to evaluate the effects of football training on maximal oxygen uptake (VO2max), ventilatory threshold (VT) and kinetics of ventilation and gas exchange variables to sinusoidal work load. The sinusoidal work load during cycling exercise was varied from 30 watts to 60% of VO2max (60% VO2max) with a period of 2 min. O2 uptake (VO2), CO2 output (VCO2), minute ventilation (VE) and heart rate (HR) were measured on a breath-by-breath basis using a computer system. Training periods were continued for 9 months. Six males who had no football experience were performed in which VO2max, VT, and the kinetics of each variable were measured for 3-month intervals (PRE, TR.3, TR.6, and TR.9). They usually underwent football training, such as sprint and strength training for 2-3 hours day-1, 6 days week-1. Mean VO2max was significantly increased at TR.3 and TR.6. VT was also significantly increased during the training period. The amplitude of VO2, VCO2, VE, and HR responses during sinusoidal exercise unchanged during the training period. Phase shifts to work load in VO2 and HR responses did not significantly change during the 9 months, but the phase shift in VCO2 and VE responses significantly continued increasing as the training intervals progressed. These results suggest that football training does not significantly affect the development of the kinetics of VO2 and HR during submaximal exercise, but that it dramatically increases VO2max and VT values.

Anaerobic Threshold↗