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Biomedical subjects

M Hatano

Publications and source records attributed to M Hatano.

At least 145 records · Page 8Linked to original sources
PubMed1990

Prospective study of late potentials to predict cardiac sudden death and ventricular tachycardias in patients with myocardial infarction surviving over 4 weeks.

We studied, prospectively, the predictive value of late potentials to cardiac sudden death and sustained ventricular tachycardias in 385 patients with myocardial infarction surviving over 4 weeks. Signal averaged electrocardiogram was performed over a 4 week period from the onset of acute myocardial infarction in all patients. Late potentials were observed in 118 of 385 patients. During the mean follow up period of 24.3 months, 17 patients had cardiac sudden death and 15 patients had symptomatic sustained ventricular tachycardias. In 16 of 17 patients with cardiac sudden death and 14 of 15 patients with sustained ventricular tachycardias, late potentials were observed. Sensitivity, specificity, positive predictive value, negative predictive value, and predictive accuracy of late potentials to cardiac sudden death in these 385 patients were 94.1%, 72.3%, 13.6%, 99.6% and 73.2% respectively. Also, these predictive values of late potentials to sustained ventricular tachycardias in the group of patients were 93.3%, 71.9%, 11.9%, 99.6% and 72.7%, respectively. We concluded that the clinical usefulness of late potentials in patients with myocardial infarction surviving over 4 weeks in the negative predictive value to cardiac sudden death and sustained ventricular tachycardias is superior to that of positive predictive value. Sensitivity of late potentials to these events is also higher.

Adult↗
PubMed1990

Adenylate cyclase activities of vascular smooth muscle in early and established DOCA/salt hypertensive rats.

It has been demonstrated that the adenylate cyclase activity of vascular smooth muscle regulates its tonus. The present study was undertaken to examine adenylate cyclase activity in early and established deoxycorticosterone acetate (DOCA)/salt hypertensive rats. Early and established DOCA/salt hypertensive rats were prepared by injecting 30 mg of DOCA weekly for 3 and 10 weeks, respectively, into male Wistar rats given drinking water with 1% saline. The membrane protein fraction medium containing the protein, 50 microM isoproterenol, 100 microM GTP, 50 microM forskolin or 25 microM calmodulin was applied. The adenylate cyclase activity was determined by a modified method developed in our laboratory using double isotope counting. The adenylate cyclase activity in the early DOCA/salt hypertensive rats was significantly higher (p less than 0.05) than that in the control rats in the basal condition, which was unaffected by additions of isoproterenol, GTP or forskolin. There was no significant difference in basal adenylate cyclase activity between the established DOCA/salt hypertensive and control rats. The adenylate cyclase activities in the established DOCA/salt hypertensive rats were significantly lower with GTP (p less than 0.02) and forskolin (p less than 0.01) as compared with the control rats. Calmodulin elevated the adenylate cyclase activity significantly (p less than 0.05) in the established DOCA/salt hypertensive rats as well as in the control rats. However, enzyme activity with calmodulin in the established DOCA/salt hypertensive rats was significantly lower (p less than 0.05) than that in the control rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1990

Effect of atrial natriuretic peptide on adrenal renin and aldosterone.

The effect of atrial natriuretic peptide (ANP) on adrenal renin and aldosterone was investigated in anesthetized rats. Under pentobarbital anesthesia 40 mg/kg), intravenous infusion of ANP (0.25 micrograms/kg/min) for 45 min failed to alter the adrenal renin, adrenal aldosterone, and plasma aldosterone (PA). In this condition, intraperitoneal injection of ACTH (10 micrograms/kg) significantly increased the adrenal renin (from 2.4 +/- 0.1 to 5.0 +/- 0.08 ng/mg protein/h, P less than 0.05), adrenal aldosterone (from 13.6 +/- 1.3 to 22.7 +/- 2.3 ng/mg protein, P less than 0.01) and PA (from 59.8 +/- 5.8 to 75.5 +/- 7.4 ng/dl, P less than 0.05), respectively. Under ACTH stimulation, ANP infusion induced significant decreases in adrenal renin (from 5.0 +/- 0.08 to 2.8 +/- 0.2 ng/mg protein/h, P less than 0.05), adrenal aldosterone (from 22.7 +/- 2.3 to 16.2 +/- 1.8 ng/mg protein, P less than 0.05) and PA (from 75.5 +/- 7.4 to 61.6 +/- 4.9 ng/dl). These results suggest a possible role for adrenal renin in the mechanism underlying the inhibitory effect of ANP on aldosterone production in vivo.

Adrenal Glands↗
PubMed1990

Preventive effect of angiotensin I on weight reduction in the adrenal glands of DOCA/salt hypertensive rats.

We examined the effect of angiotensin I (AI), without the effect of angiotensin II (AII) converted from AI, on the weight of the adrenal glands, adrenal corticosterone (B) and adrenal aldosterone under conditions where the renin-angiotensin system was suppressed, since a reduction in the size of the adrenal glands is often observed in DOCA/salt hypertensive rats. Sixty male Wistar rats fed on a 1% NaCl solution were divided into 6 groups as follows: a) Salt group: received sesame oil and vehicle, b) Salt + C group: received sesame oil and MK422 (0.14 mg/day), an angiotensin converting enzyme inhibitor (CEI), c) DOCA group: received DOCA (30 mg/week) and vehicle, d) DOCA + A group: received DOCA and AI (0.5 mg/kg/day), e) DOCA + A + C group: received DOCA and AI with MK422, and f) DOCA + C group: received DOCA and MK422. After 4 weeks, the rats were sacrificed to sample their blood and remove their adrenal glands. There was no significant difference in adrenal B among the groups apart from the DOCA + C group. Adrenal aldosterone was lower in the groups of DOCA/salt hypertensive rats than in the Salt group and Salt + C group. Furthermore, the DOCA + A + C group and DOCA + C group had lower adrenal aldosterone levels than the DOCA group and DOCA + A group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1990

[The clinical role of anaerobic threshold in physical training of patients with recent myocardial infarction].

Twenty-seven patients with recent myocardial infarction were studied to evaluate the clinical usefulness of the anaerobic threshold (AT) in physical training as cardiac rehabilitation at home. The 27 patients were divided into trained and control groups. Symptom-limited treadmill exercise tests were conducted before and six weeks after the prescribed aerobic training. Heart rate (HR), systolic blood pressure and respiratory gases (VO2, VCO2 and VE) were noninvasively measured throughout the exercise periods. AT was defined as systemic increase in the ventilatory equivalent O2 (VE/VO2) without an increase in the ventilatory CO2 (VE/VCO2) during the increasing work load. The patients in the trained group were obliged to perform aerobic walking training requiring 90-100% HR of the AT level for 30 min, four to six days per week. 1. In the trained group, exercise time, peak VO2, and AT on treadmill performance were significantly increased compared with those of the pre-training values. However, in the control group, these parameters were not significantly changed. A significant reduction in double products was observed during submaximal workload in the trained group. 2. Factors related to the training effects: The training effect expressed by delta peak VO2 correlated significantly with the initial peak VO2 (pre-training peak VO2) (y = 35.4 - 1.29x, r = 0.70), but there was no correlation between left ventricular function and delta peak VO2. These results indicated that aerobic exercise at home guided by the AT level is safe and beneficial for patients with recent myocardial infarction.

Anaerobic Threshold↗
PubMed1990

Maxillary growth after two-stage palatal closure in complete (unilateral and bilateral) clefts of the lip and palate from infancy until 10 years of age.

The purpose of the study is to clarify the maxillary growth effects following different types of palatal closure in complete clefts of the lip and palate from infancy to 10 years of age. Lip repair, carried out at 5 months in one stage, was accomplished by Tennison's procedure. These patients were then assigned randomly to each of the 4 experimental groups according to the types of clefts and of palatal closure. One group of 14 patients in unilateral cases (Unil-S) and another group of 8 patients in bilateral cases (Bil-S) received mucoperiosteal palatal push-back procedure in a single stage at 20 months. The third group of 16 patients in unilateral cases (Unil-T) and the fourth group of 7 patients in bilateral cases (Bil-T) received the two-stage palatal closure based on Perko technique in which primary veloplasty was accomplished at 20 months and hard palate closure at 5 year 10 months. Non-cleft subjects were served as Controls. A longitudinal maxillary growth was monitored by the measurements of maxillofacial cast models obtained from each of the subjects. The results showed that the growth in depth and height of the maxilla of the Unil-T showed catch-up growth after primary veloplasty and resulted in no significant differences compared to that of the Control in the later phases, however, the Unil-S did not. The maxillary growth inhibition in height was characteristic in both Bil-S and Bil-T after palatal closure. There were no differences between the Bil-S and Bil-T in any dimensions and observation phases. The results indicate that the employment of the two-stage palatal closure is more beneficial for the unilateral cases, however, careful consideration is needed in bilateral cases.

Cephalometry↗
PubMed1990

Examination of toxicity of diisopropylammonium dichloracetate (DADA), remedies for cardiac diseases, toward isolated rat hepatocytes.

Oxygen uptake (OU) and cell viability (CV) of isolated rat hepatocytes as a part of the indexes of hepatopathy were determined following treatment with DADA, the active principle of pangamic acid. DADA increased OU at high concentrations, but not at low ones. However, CV became higher as the concentration became lower. DADA led to no remarkable toxicity when used alone. When the mixture of DADA and calcium gluconate was tested, DADA showed no palliative action; nor did it when combined with other hepatotoxins such as trapidil, rifampicin, hexobarbital, thiopental sodium, and Citanest-octapressin.

Animals↗
PubMed1990

Determination of 2,5-hexanedione and N-methylformamide in urine by gas chromatography.

Methods for the clinical testing of 2,5-hexanedione and N-methylformamide, urinary metabolites of n-hexane and N,N-dimethylformamide, respectively, were established by capillary column GLC. Recovery rates of 2,5-hexanedione and N-methylformamide from urine were 80.2-108.9% and 99.6-104.2%, respectively. Coefficients of variation (C.V.) for the amount of each product added were 3.1%, 1.8% (intra-assay) and 5.7%, 3.3% (inter-assay), respectively. The concentration ranges of metabolites from urine of healthy subjects without exposure to these organic solvents were less than or equal to 0.5 mg/l (2,5-hexanedione), less than or equal to 1.5 mg/l (N-methylformamide), respectively.

Air Pollutants, Occupational↗
PubMed1990

Studies on clinical markers of diabetes mellitus. 6. Red blood cell sorbitol and diabetic complications.

The relationship between red blood cell sorbitol content and diabetic complications (cataract, retinopathy, neuropathy, and nephropathy) was examined in 23 non-insulin-dependent diabetic (NIDD) patients. Sorbitol content was abnormally high in 21 cases out of 23 NIDD patients. Sorbitol content in the non-neuropathy group and neuropathy group was 47.3 +/- 11.9 and 59.6 +/- 23.6 nmol/gHb, respectively. In the non-cataract group and cataract group, it was 49.0 +/- 17.6 and 66.0 +/- 23.5 nmol/gHb, respectively. The contents in the Scott I group and Scott II + III group were 54.9 +/- 20.7 and 58.7 +/- 24.0 nmol/gHb, respectively. Sorbitol content in the non-nephropathy group and nephropathy group was 52.8 +/- 19.8 and 61.1 +/- 21.9 nmol/gHb, respectively. The possibility that glyceraldehyde reductase (GAR) and sorbitol dehydrogenase (SDH) levels in red blood cells are also useful indicators of the presence of diabetic complications is strongly suggested.

Biomarkers↗
PubMed1990

Effects of the thromboxane A2 analogue, STA2, on the transmembrane potentials of guinea pig ventricular muscles under normal and simulated ischaemic conditions.

To assess whether thromboxane A2 (TXA2) exerts a direct electrophysiological effect on cardiac muscle, the effects of STA2 (10 micrograms/l), a stable TXA2 analogue, on the action potentials were examined in isolated guinea pig ventricular muscles using conventional microelectrode techniques. STA2 failed to induce any significant changes in the action potential characteristics in both normal Tyrode's solution and the hyperkalemic (K+ = 10.8 mM) solution. 15 min of superfusion with the "ischemic" solution, which consisted of hyperkalemia (K+ = 10.8 mM), hypoxia (pO2 less than 50 mmHg), acidosis (pH = 6.4) and substrate deprivation (glucose-free), progressively shortened the action potential duration and reduced the resting membrane potential, action potential amplitude and Vmax. STA2 did not affect the changes in the action potential during such "ischemic" superfusion. These results indicate that STA2 exerts no direct electrophysiological effects on both the normal and the "ischemic" myocardium. The arrhythmogenic effects of TXA2 observed in in vivo studies might reflect the ability of TXA2 to induce platelet aggregation and vasoconstriction resulting in an exacerbation of myocardial ischemia.

Action Potentials↗
PubMed1990

Administration of calcium carbonate with adequate doses of vitamin D metabolite to patients on hemodialysis improves mild secondary hyperparathyroidism.

The effects of CaCO3 with vitamin D metabolite and without vitamin D metabolite on secondary hyperparathyroidism were investigated in 18 patients undergoing maintenance hemodialysis. 9 patients (Group 1) were treated with 1 microgram/day 1 alpha (OH)D3 and 2 g/day Al(OH)3, and the other 9 patients (Group 2) received 2 g/day Al(OH)3 without vitamin D metabolite. CaCO3 at amounts of 3 g/day was subsequently administered to all patients instead of Al(OH)3. The levels of mid portion-parathyroid hormone (M-PTH) in Group 2 and of 1,25-dihydroxyvitamin D3 in Group 1 during the baseline period were significantly increased as compared to those in the other group, respectively. In Group 1 only, the level of serum ionized calcium was appreciably elevated at the 4th and 12th weeks as compared to the baseline value, and the level of M-PTH was significantly decreased at the 4th and 12th weeks as compared to the baseline value. The levels of serum phosphate, calcitonin, magnesium and bicarbonate in both groups at the 4th and 12th weeks were not appreciably different from the baseline values. The level of serum aluminum in all patients of both groups were reduced at the 12th week as compared to the baseline values. A close correlation was recognized between M-PTH and the level of intact parathyroid hormone. It is concluded that prescription of 3g/day CaCO3, together with adequate doses of vitamin D metabolite, can ameliorate mild secondary hyperparathyroidism.

Adult↗
PubMed1990

[Valvular regurgitation in patients with complete heart block by color Doppler echocardiography].

We studied valvular regurgitation (pulmonary, aortic, tricuspid and mitral regurgitation) in 30 patients with complete heart block by color Doppler echocardiography, pulse Doppler and continuous wave Doppler echocardiography. The prevalence rate of multivalvular regurgitation of these subjects was 83.3%. Regurgitation involving all four valves appeared in 30.0% of these patients. The prevalence rate of pulmonary, aortic, tricuspid and mitral regurgitation was 56.7%, 33.3%, 100%, and 76.7% respectively. Pulmonary regurgitation (PR) was observed in patients with complete heart block without pulmonary hypertension. PR velocity was slow and interrupted by atrial contraction. It might be possible to evaluate atrial pressure from the interruption of PR. Tricuspid regurgitation (TR) during systole was often present in patients with right ventricular endocardial pacing. Systolic TR was influenced by atrial contraction. When atrial contraction occurred during systole, TR was interrupted, or shortened. Diastolic TR and MR were easily detected by M mode color Doppler echocardiography. The diastolic TR and MR were of slow velocity and appeared 240-290 msec after P wave. These atypical valvular regurgitation in patients with complete heart block reflect of the inverse atrial-ventricular pressure gradient across the atrio-ventricular valve.

Adult↗
PubMed1990

[Production of C3 nephritic factor by cultured lymphocytes derived from glomerulonephritic patients].

C3 nephritic factor (C3 NeF) has been found mainly in the sera of patients with membranoproliferative glomerulonephritis (MPGN) and partial lipodystrophy (PLD). We examined whether peripheral blood mononuclear cells (PBMC) from patients with PLD and MPGN could produce C3 NeF. We investigated the in vitro immunoglobulin synthesis of PBMC with mitogen. We further studied whether or not C3 NeF was included in the IgG of the culture supernatants by the C3bBb stabilizing activity and agglutination assay. The IgG of PLD patient was able to agglutinate only EAC4bBb cells and none of the other intermediate cells. We thus demonstrated that C3 NeF could be produced in vitro by PBMC derived from the patient with PLD. However, as regard case of C3 NeF weakly positive and C3 NeF negative patients, C3 NeF couldn't be produced in vitro by PBMC derived from the patients.

Adolescent↗