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Biomedical subjects

T Mano

Publications and source records attributed to T Mano.

At least 163 records · Page 9Linked to original sources
PubMed1996

A case of myocarditis associated with IDDM.

We report a case of diabetic ketoacidosis (DKA) complicated by acute myocarditis, which was confirmed by cardiac biopsy. A 26-year-old man was hospitalized with severe DKA. On admission, nonspecific ST-T change was noted on the electrocardiogram (ECG). The patient's levels of creatine phosphokinase (CPK) and glutamic oxaloacetic transaminase were slightly elevated, but he did not complain of chest discomfort or symptoms of heart disease. On the first day after admission, ST-T elevation was noted on ECG during treatment of DKA. By cardiac angiography and cardiac biopsy, coronary heart disease was ruled out and postmyocarditic change was histologically confirmed. An episode of upper respiratory viral infection before the onset of acute diabetes suggested that the patient suffered from viral-induced myocarditis and consequent development of IDDM. This possibility was confirmed by the clinical course of ECG change, with elevated CPK and lactate dehydrogenase and a slightly elevated antibody titer for echovirus.

Adult↗
PubMed1996

Spectral characteristics of heart rate and blood pressure variabilities during head-out water immersion.

To elucidate the roles of the autonomic nervous system in cardiovascular adaptation to microgravity, spectral analysis of heart rate and blood pressure variabilities were conducted during thermoneutral head-out water immersion in 8 healthy young subjects aged 23 to 31 years. In all subjects immersed up to the shoulder, the low-frequency (LF: 0.04-0.15 Hz) component in blood pressure variability and the ratio of LF power to high-frequency power (LF/HF ratio) in heart rate variability decreased, while the high-frequency (HF: 0.15-0.5 Hz) component of heart rate variability increased. Concomitantly, a decrease in heart rate was observed without significant changes in blood pressure during immersion. These results suggest that cardiac and vasomotor sympathetic nerve activities are suppressed and cardiac parasympathetic (vagal) nerve activity is activated during head-out water immersion.

Adult↗
PubMed1996

Sympathetic outflow response to muscle during vestibular stimulation in humans.

To observe the effects of caloric vestibular stimulation on muscle sympathetic nerve activity (MSNA) in humans, 14 healthy volunteers were monitored in a supine position by electrocardiogram (ECG), blood pressure (BP), electro-oculogram (EOG). MSNA was monitored by a double recording technique of microneurography from the bilateral tibial nerves. Caloric vestibular stimulation was loaded by injecting 50 ml 44 degrees C warm water and 50 ml 10 degrees C cold water alternately into the external meatus for 1 min. Nystagmus was evoked in all cases by cold stimulation and in some cases by hot stimulation. The nystagmus evoked by cold stimulation was more intense than that by hot stimulation. MSNA was enhanced by either cold or hot stimulation; however, the enhancement mode differed between cold and hot stimulation. Cold stimulation evoked two peaks of MSNA while hot stimulation elicited only one peak. The first peak (404.5 +/- 115.4% with control value set at 100%, mean +/- SE) was estimated to be caused by cold stimulation on the skin of the external meatus while the second peak (379.2 +/- 65.3%) seemed to be the result of vestibular stimulation. With hot stimulation, the response peak of MSNA was 243.3 +/- 28.1%. In general, MSNA was enhanced after vestibular stimulation with MSNA increases was proportional to the stimulated level of the vestibular system.

Adult↗
PubMed1996

[Visual functional changes in idiopathic macular holes treated by vitrectomy].

We evaluated visual functional measurements, visual acuity, central retinal sensitivity in a Humphrey field analyzer, and binocular function in Stereotest, Amsler grid testing, of 51 idiopathic macular holes before and after vitrectomy. In 36 of 51 eyes (71%) where the macular hole was closed after vitrectomy, there were improvements in all visual functional measurements postoperatively. The eyes in which the macular hole was closed had significantly better visual acuity before vitrectomy than those in which the hole was not closed. In 16 of 51 eyes that had visual acuity of less than 20/200 preoperatively, central retinal sensitivity before vitrectomy was higher in the eyes where the macular hole was closed than in those in which it was not closed. These measurements are useful for evaluation of visual functional improvements after vitrectomy and can help to choose candidates for macular hole surgery.

Adult↗
PubMed1996

[Outcome of initial treatment with high-dose vitamin B6, valproate sodium or clonazepam in West syndrome].

We reviewed the outcome (seizures and development) of 25 cases with West syndrome in which antiepileptic drugs (valproate sodium, clonazepam) or high doses of vitamin B6, instead of ACTH therapy, were administered for the initial treatment. Five of 9 cryptogenic cases (56%) and 4 of 16 symptomatic cases (25%) showed complete cessation of spasms. In cryptogenic cases, response to vitamin B6, valproate sodium or clonazepam was not predicted by clinical features (age of onset, seizure type, initial EEG finding or treatment lag). On the other hand, response to these drugs was correlated with some clinical findings in symptomatic cases; all infants with neurocutaneous syndrome (tuberous sclerosis, neurofibromatosis type 1) had controlled infantile spasms, while none of patients with severe neonatal asphyxia or with prior other seizures responded. Twenty of 25 patients have been followed-up. The average age at follow-up was 5 years and 8 months. Prognosis of both cryptogenic and symptomatic "responders" was favorable; all had seizures controlled, and 50% had normal psychomotor development or only mild impairment (DQ > 70). Symptomatic "nonresponders" had the worst prognosis. Our results suggest that choice of drug in the initial treatment of West syndrome should be determined by clinical features (especially etiology).

Anticonvulsants↗
PubMed1995

Effect of oral ethanol intake on muscle sympathetic nerve activity and cardiovascular functions in humans.

The aim of the present study was to clarify the acute effect of alcohol drinking on muscle sympathetic nerve activity and other cardiovascular variables in young healthy human volunteers. Seven volunteers (25.0 +/- 4.7 years in age, weighing 59.9 +/- 5.9 kg) were instructed to lay down on a bed, and muscle sympathetic nerve activity (MSNA) was microneurographically recorded from the tibial nerve, simultaneously with an electrocardiogram, blood pressure with Finapres and autosphygmomanometer, cardiac output by impedance cardiography, and skin blood flow by laser Doppler flowmetry. After a 1-h rest, the subjects drank alcohol (0.6 g/kg) and were remained in resting position for 105 min. Blood ethanol levels indicated that they were moderately intoxicated. Heart rate constantly increased until 30 min after the ingestion, and maintained a peak level. MSNA was slightly but significantly suppressed just after the ingestion, and was gradually enhanced until the end of the experiment, showing a significant difference from the control level until 40 min in burst rate and until 25 min in total MSNA after the ingestion. Blood pressure showed an abrupt and transient increase at first, then gradual decrease until 30 min after the ingestion, and maintenance of the resting level until the end of the experiment. Cardiac output showed no constant tendency and no significant differences after the ingestion with wide interindividual variation. Skin blood flow increased 15 min after the ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1995

[A rare case of a diabetic patient with small cell lung cancer, initially diagnosed as pyogenic vertebral osteomyelitis].

A rare case of a patient with non-insulin-dependent diabetes mellitus (NIDDM) with small cell lung cancer, initially diagnosed as pyogenic vertebral osteomyelitis, was reported. A 40-year-old male patient was diagnosed with NIDDM about 3 years earlier, but he did not receive any treatment. Then, a two-month history of high fever, persistent cough and back pain developed. Chest X-ray film showed a lung infiltrate with a small cavity in the upper portion of the left lung. Computed tomography and magnetic resonance imaging of the chest revealed a tumor mass shadow with osteoclasia along the bodies of the 6th and 7th thoracic vertebral bone. Staphylococcus aureus infection was confirmed by arterial blood culture. Administration of antibiotics resulted in the disappearance of the left lung infiltrate and a slight reduction of the tumor mass in the thoracic vertebral bone, suggesting pyogenic vertebral osteomyelitis as an unusual complication of NIDDM. However, as the tumor mass still remained, needle biopsy for the mass lesion was performed, resulting in the diagnosis of metastasis of small cell carcinoma from the left lung. Gene aberration in this lung disease has been reported recently, and its correlation with NIDDM which may also be induced by genetic abnormality is an interesting question that remains to be resolved.

Adult↗
PubMed1995

Digital subtraction high-frame-rate echocardiography in detecting delayed onset of regional left ventricular relaxation in ischemic heart disease.

BACKGROUND: Because left ventricular (LV) diastolic function is impaired before systolic function in patients with ischemic heart disease and because ischemic heart disease is constituted of regional rather than global abnormalities of the left ventricle, measures of LV regional diastolic dysfunction, if possible, should provide the most sensitive assessment of the coronary involved region. The objectives of this study are to clarify whether high-frame-rate two-dimensional echocardiography, combined with digital subtraction image processing, may be used to visualize regional LV relaxation abnormalities in patients with ischemic heart disease and to clarify whether this technique provides a measure for the noninvasive assessment of the coronary involved region. METHOD AND RESULTS: In 30 normal subjects and 59 patients with ischemic heart disease, two-dimensional echocardiograms obtained at a rate of 60 frames per second were provided on line for digital subtraction analysis, with which digitized images were continuously subtracted on a frame-by-frame basis. The subtracted images were analyzed to determine the onset of the segmental outward motion of the LV wall in early diastole in each of 16 segments per subject. Regional relaxation index, defined as the interval from the second heart sound to the onset of outward wall motion, was significantly prolonged in the coronary involved segments compared with the normal segments (36.3 +/- 18.0 versus 101.2 +/- 34.0 ms, P < .01). The prolongation in the regional relaxation index was observed even in the coronary involved segments without reduction in systolic wall motion. When a cutoff level of 50.0 ms was used, coronary involved segments could be distinguished from normal or border segments with a sensitivity of 92% and a specificity of 81%. CONCLUSIONS: Digital subtraction high-frame-rate echocardiography may be used to visualize regional LV relaxation abnormalities in patients with ischemic heart disease. The time interval from the second heart sound to the onset of the segmental outward motion of the LV wall (regional relaxation index) obtained with this technique provides a noninvasive and accurate measure for assessing coronary involved regions.

Adult↗
PubMed1995

Noninvasive assessment of left ventricular relaxation using continuous-wave Doppler aortic regurgitant velocity curve. Its comparative value to the mitral regurgitation method.

BACKGROUND: The most established parameters of left ventricular (LV) relaxation are peak negative value of the first derivative of LV pressure (-dP/dtmax) and the time constant of isovolumic LV pressure fall. The instantaneous pressure gradient between the aorta and the LV during diastole can be calculated from the continuous-wave Doppler aortic regurgitant velocity spectrum. Because the fluctuation of aortic pressure during LV isovolumic relaxation is negligibly minor and because LV minimal pressure is negligibly low, LV pressure during the isovolumic relaxation period may be derived from the continuous-wave Doppler aortic regurgitant velocity spectrum. This study was designed to clarify whether analysis of continuous-wave Doppler aortic regurgitation recording provides accurate measures of LV relaxation over a wide range of LV function and to determine comparative values of aortic and mitral regurgitation methods in the assessment of LV relaxation. METHODS AND RESULTS: In eight mongrel dogs with acute ischemic LV dysfunction, the continuous-wave Doppler aortic regurgitant velocity spectrum was recorded simultaneously with high-fidelity LV and aortic pressures, while the continuous-wave Doppler mitral regurgitant velocity spectrum was recorded simultaneously with high-fidelity left atrial and LV pressures. The aortic regurgitant velocity spectrum was provided for the determination of Doppler-derived mean rate of LV pressure fall in 20 ms after the onset of aortic regurgitation (delta P/delta t-AR) and the time interval from the onset of aortic regurgitation to the point at (1-1/e)1/2 of the maximal aortic regurgitant velocity as an estimate of the time constant. The mitral regurgitant velocity spectrum was provided for Doppler-derived mean rate of LV pressure fall in 20 ms after the point of -dP/dtmax (delta P/delta t-MR) and the time interval from the point of -dP/dtmax to the point with mitral regurgitant velocity of (1/e)1/2 of the mitral regurgitant velocity at the point of -dP/dtmax as an estimate of the time constant. delta P/delta t-AR and delta P/delta t-MR correlated well with catheter-derived -dP/dtmax (r = .92, r = .98, P < .01, respectively). The time constant derived from aortic and mitral regurgitant velocity spectra (tau-AR and tau-MR) also correlated well with catheter-derived time constant (r = .84, r = .76, P < .01, respectively). However, a mean difference of the catheter-derived time constant minus tau-MR was larger than tau-AR (29 +/- 30 versus 4 +/- 17 ms, P < .01, presented as mean +/- 2 SD). CONCLUSIONS: LV relaxation can be assessed from the continuous-wave Doppler aortic regurgitant velocity spectrum. The aortic regurgitation method provides an even more accurate estimate of the time constant compared with the mitral regurgitation method, particularly in the presence of LV dysfunction.

Animals↗
PubMed1995

Interaction between valproate formulation and phenytoin concentrations.

Changes in phenytoin concentrations caused by switching valproate formulations with different absorption rates were retrospectively investigated in eleven epileptic patients receiving treatment with both drugs. Total plasma phenytoin concentrations were measured before and after a standard tablet of valproate was replaced by the same dose as a slow-release tablet. The mean plasma phenytoin level rose significantly from 14.4 to 18.7 micrograms.ml-1. Nine of eleven patients had markedly increased phenytoin levels (by 21 to 72%), and two developed toxic symptoms. The results indicate that changing valproate formulations can cause major alterations in the plasma concentration of co-administered phenytoin.

Adolescent↗
PubMed1995

Intraventricular dispersion of early diastolic filling: a new marker of left ventricular diastolic dysfunction.

Mitral flow velocity patterns are frequently "normalized" by the alteration in the loading condition even in the presence of left ventricular (LV) diastolic dysfunction. In addition, a simple index, the ratio of mitral peak early diastolic flow velocity to mitral peak flow velocity at atrial contraction, is not obtainable in patients with atrial fibrillation (Af). Thus these limitations hamper the value of analyzing the mitral flow velocity pattern in the assessment of abnormal LV diastolic characteristics. This study was designed to elucidate the hypothesis that peak early diastolic flow velocity decreases progressively from the base to the apex in patients with LV diastolic dysfunction. Regional diastolic flow velocity patterns at 1, 2, or 3 cm from the mitral tip toward the apex were simultaneously recorded with the mitral flow velocity pattern by using multigate pulsed Doppler echocardiography in 42 subjects with normal LV function (31 normal volunteers and 11 patients with Af only), 17 patients with hypertensive heart disease, and 22 patients with dilated cardiomyopathy. In the normal subjects early diastolic flow velocity at the mitral tip was maintained at the positions 1 to 3 cm away from the tip into the LV cavity. In contrast, regional peak early diastolic flow velocity progressively decreased toward the apex in patients with hypertensive heart disease and dilated cardiomyopathy. These findings were observed even in patients with a normalized mitral flow velocity pattern or those with Af. Thus the assessment of the intraventricular decrease in peak early diastolic flow velocity may be useful in detecting LV diastolic dysfunction, particularly in patients with Af or a "normalized" mitral flow velocity pattern.

Adult↗
PubMed1995

Doppler echocardiographic pulmonary venous flow-velocity pattern for assessment of the hemodynamic profile in acute congestive heart failure.

The hemodynamic profile of congestive heart failure (CHF) is best described in terms of its two primary sets of hemodynamic parameters, that is, left atrial pressure and cardiac output, each of which has a specific and independently variable hemodynamic cause. To assess whether analysis of the mitral and/or pulmonary venous flow-velocity patterns provides valuable information in the noninvasive assessment of the hemodynamic profile of CHF, these patterns were obtained by using the transthoracic approach in 18 patients with acute CHF with simultaneous measurements of catheter-derived mean pulmonary capillary wedge pressure and thermodilution cardiac index. Measurements were repeated on two occasions in each case: at the acute stage of CHF and 1 to 5 days after treatment. Peak diastolic pulmonary venous forward flow velocity was higher, the ratio of pulmonary venous systolic to diastolic peak forward flow velocity was lower, and the ratio of mitral early diastolic to late diastolic flow velocity was greater in patients with higher mean pulmonary capillary wedge pressure (r = 0.80, n = 36, p < 0.01; r = -0.69, n = 36, p < 0.01; r = 0.71, n = 36, p < 0.01). Peak systolic pulmonary venous forward flow velocity and time-velocity integral of the systolic pulmonary venous flow wave were greater in patients with larger cardiac index (r = 0.80, n = 36, p < 0.01; r = 0.62, n = 36, p < 0.01). In conclusion, two primary sets of hemodynamic parameters, that is, left atrial pressure and cardiac output, can be estimated with Doppler pulmonary venous flow parameters in patients with acute CHF.

Acute Disease↗
PubMed1995

Effects of premotion silent period on single motor unit firing at initiation of a rapid contraction.

We compared the single motor unit (SMU) activity between movements with a premotion silent period (PMSP) and without PMSP in EMG. Fourteen SMUs in the gastrocnemius muscle and 6 SMUs in the soleus muscle were recorded from 5 volunteers during isometric plantar flexion. Tonically firing SMUs failed to fire just before the onset of a rapid contraction with PMSP more frequently than without PMSP. SMUs tended to fire within 10 msec (the gastrocnemius SMUs) or 20 msec (the soleus SMUs) from the onset of the phasic EMG discharge when PMSP occurred. In a rapid contraction without PMSP, the initial firing of SMUs occurred with longer latency than that in a rapid contraction with PMSP. The latency of the initial SMU firing in a rapid contraction related to the preceding time of the last SMU firing during a sustained contraction to the onset of the phasic EMG discharge. When the preceding firing was long enough, the latency distributed around 10 msec. On the other hand, for shorter preceding times, the latency lengthened with shortening of the preceding time. It is suggested that the PMSP makes the preceding time long and increases the susceptibility of motor units to the descending command at the initiation of a rapid contraction.

Adult↗
PubMed1995

Validation of transthoracic myocardial ultrasonic tissue characterization: comparison of transthoracic and open-chest measurements of integrated backscatter.

To investigate whether myocardial integrated backscatter (IB) can be measured through the chest wall, myocardial IB parameters were measured in five adult mongrel dogs with a newly developed IB imaging system capable of measurements of myocardial IB relative to backscatter from the blood. There was no significant difference in the calibrated myocardial IB between the closed chest and the open chest conditions either in the septum or in the posterior wall if a 2.5- or 3.5-MHz frequency transducer was used. There was no significant difference in the magnitude of cyclic variation in IB between the closed chest and the open chest conditions independent of the frequency of the transducer used. These data suggest that we can accurately measure not only the magnitude of cyclic variation in IB but also the calibrated myocardial IB through the chest wall with a 2.5- or 3.5-MHz frequency transducer. Such data may validate measurements of myocardial IB parameters through the chest wall even in humans.

Algorithms↗
PubMed1995

Degree of external force to the left ventricle determines hemodynamic response to nitroprusside in failing hearts: comparison with the response to dobutamine.

Vasodilators frequently, although not always, increase cardiac output (CO) in patients with congestive heart failure (CHF) despite a decrease in left ventricular (LV) diastolic pressure. In patients with CHF, vasodilator-induced decrease in LV diastolic pressure without decrease in "preload" plays an important role in the vasodilator-induced increase in CO failure that may be caused by a vasodilator-induced reduction in external force to the LV. To clarify the hypothesis that a hemodynamic response to vasodilators depends on the degree of external force to the LV in failing hearts before drug administration and to examine whether the degree of the external force also affects a hemodynamic response to positive inotropic agents, we produced in 17 dogs two different conditions of LV dysfunction with high LV end-diastolic pressure (EDP: > or = 15 mm Hg), i.e., 1 with high right ventricular (RV) EDP (condition 1) and the other with lower RVEDP than condition 1 (condition 2), and compared hemodynamic effects of nitroprusside or dobutamine between these two conditions. Condition 1 was produced by the injection of a small dose of microspheres into the left coronary artery and intravenous infusion of dextran. Condition 2 was produced only by the injection of a large dose of microspheres. The nitroprusside-induced decrease in LVEDP was associated with a greater decrease in RVEDP and lesser decreases in mean left atrial pressure and LV end-diastolic diameter in condition 1 than in condition 2. CO increased in condition 1; however, CO then decreased in condition 2. The nitroprusside-induced changes in CO inversely correlated with those in RVEDP (r = 0.65, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗