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Biomedical subjects

S H Sheu

Publications and source records attributed to S H Sheu.

At least 19 recordsLinked to original sources
PubMed2004

A double-blind comparison of the efficacy and tolerability of telmisartan 40-80 mg vs. losartan 50-100 mg in Taiwanese hypertensive patients.

A multicentre, randomised, double-blind, double-dummy, parallel-group, dose-titration study was conducted to determine the efficacy and tolerability of telmisartan 40-80 mg once daily compared with losartan 50-100 mg once daily in 180 Taiwanese patients with mild-to-moderate essential hypertension. After an initial 2-week placebo run-in phase, patients were randomised in a double-blind, double-dummy fashion to receive either telmisartan 40 mg or losartan 50 mg. If blood pressure control (diastolic blood pressure [DBP] <90 mmHg or > or = 10 mmHg reduction in DBP) was achieved after 4 weeks, the dose was maintained for the second 4 weeks of the active treatment phase; if not, the dose was doubled to telmisartan 80 mg or losartan 100 mg, respectively, for the second 4 weeks of double-blind treatment. Telmisartan 40-80 mg (n = 86) was as effective as losartan 50-100 mg (n = 90) in reducing trough seated DBP (11.1 vs. 8.7 mmHg, p = 0.144), and was significantly more effective than losartan in reducing trough seated systolic blood pressure (SBP) (22.1 vs. 16.5 mmHg, p = 0.032) and standing SBP (21.0 vs. 16.3 mmHg, p = 0.033). Significantly fewer patients treated with telmisartan than those treated with losartan required uptitration after 4 weeks' treatment (32.6% vs. 61.5%, p = 0.001). Both telmisartan and losartan were well tolerated.

Adult↗
PubMed2001

Treatment of olefin plant spent caustic by combination of neutralization and Fenton reaction.

Spent caustic from olefin plants contains much H2S and some mercaptans, phenols and oil. A new treatment process of spent caustic by neutralization followed by oxidation with Fenton's reagent (Fe2+/H2O2) was successfully developed. Over 90% of dissolved H2S were converted to gas phase by neutralization at pH = 5 and T = 70 degrees, and the vent gas stream could be introduced to sulfur recovery plant. The neutralized liquid was oxidized with OH. free radical, which was provided by a Fenton's reagent. The residual sulfides in the neutralized spent caustic were oxidized to less than 0.1 mg/L. The total COD removal of spent caustic is over 99.5% and the final COD value of the effluent can be lower than 100 mg/L under the following oxidation conditions: reaction time = 50 min, T = 90 degrees, Fe2+ = 100 mg/L, and a stoichiometric H2O2/COD = 1.1. The value is better than the 800 mg/L value obtained by common WAO process. The optimum pH of the Fenton reaction is around 2 for this process, and the oxidation step can maintain a pH value in the range of 1.8-2.4. Moreover, the iron catalyst can be recycled without affecting process effectiveness thus preventing secondary pollution.

Alkenes↗
PubMed2001

Seasonal variability of the QT dispersion in healthy subjects.

We studied the seasonal variability of QT dispersion in 25 healthy subjects, aged 36 +/- 5 (25 to 46) years. Four seasonal 12-lead rest electrocardiograms (ECGs) recorded at a double amplitude were performed at 25 mm/s at intervals of roughly 3 months. To avoid possible confusion from the circadian rhythm of QT dispersion, subsequent ECGs were recorded within 30 minutes of the reference summer one. The QT dispersion was calculated as the difference between the longest and the shortest mean QT intervals. There was a seasonal variability in the QT dispersion (P =.001), with the largest QT dispersion occurring in winter (66 +/- 21 ms) and the smallest one in spring (48 +/- 18 ms). In conclusion, there exists a seasonal variability of QT dispersion in healthy subjects and such variability should be taken into consideration in comparison of the QT dispersion.

Adult↗
PubMed2001

A prospective study of p53 expression and its correlation with clinical response of radiotherapy in nasopharyngeal carcinoma.

OBJECTIVES/HYPOTHESIS: Nasopharyngeal carcinoma (NPC) is a common malignant neoplasm of the head and neck that occurs in people in the southeastern Asian area, including Taiwan. The significant association of p53 expression in NPC suggested that p53 overexpression seemed to occur at an early stage in the development of NPC. Alterations of p53 status were probably the most commonly encountered in head and neck carcinomas, and there was extensive evidence that p53 status might determine tumor response to therapy. Ionizing radiation was studied extensively for the relationship between its damaging effect and p53 status in human cancer cells. STUDY DESIGN: This study was carried out to investigate whether there was any correlation between overexpression of p53 protein and locoregional tumor response in patients with NPC treated with 7000 cGy of radiotherapy. METHODS: Sixty-eight patients (50 males, 18 females) with NPC who were diagnosed and treated with radiotherapy were studied prospectively. Before they had received a radiation dose of 7000 cGy in 35 fractions, five fractions a week, p53 status from a nasopharyngeal biopsy was studied using immunohistochemical staining (IHC). RESULTS: The locoregional response rate of primary tumor was analyzed statistically. Forty-seven patients (69.1%) showed positive p53 staining in their tumors. There were 5 positive stains in 6 squamous cell carcinomas (SCC; 83.3%), 34 positive in 53 non-keratinizing carcinomas (NKC; 64.2%), and 8 positive in 9 undifferentiated carcinomas (UC; 88.9%). The mean ages for patients with three different histopathologies were 48.5, 46.1, and 61.1 years. There were 8 patients (7 positive stains, 1 negative stain) with residual tumor after radiotherapy and all were NKC (6 males, 2 females). Therefore, the clinical response rate of primary tumor was 85.1% in positive p53 immunostaining (40 of 47 cases), 95.2% in those with no immunostaining (20 of 21 cases); the former was poorer in locoregional tumor response than the latter, but there was no significant difference (P > .05, chi2 test). CONCLUSIONS: We conclude that there is no statistically significant correlation in locoregional response of primary tumor between p53 overexpression and radiotherapy in patients with NPC (P > .05, Fisher exact test).

Adolescent↗
PubMed2001

Role of intraventricular dispersion of early diastolic filling in indicating left ventricular diastolic dysfunction: assessment by color M-mode inflow propagation velocity.

The intraventricular to mitral E velocity ratio (IvE/MvE) and the color M-mode Doppler inflow propagation velocity (LVIPV) were evaluated in 36 healthy controls and 33 patients with hypertension and/or ischemic heart disease. The intraventricular E velocity was significantly lower than the mitral E velocity in the control group (52 vs. 68 cm/s, p < 0.001), but they are similar in the disease group (59 vs. 63 cm/s, p = nonsignificant). Compared with the control group, the disease group had a higher IvE/MvE (0.95 +/- 0.28 vs. 0.78 +/- 0.23, p < 0.01). Nevertheless, the LVIPV was not significantly different between the disease and control groups (53 +/- 14 vs. 56 +/- 13 cm/s, p = nonsignificant). The LVIPV did not correlate with the IvE/MvE (r = 0.202, p = nonsignificant). Therefore, an intraventricular dispersion of early diastolic filling does not seem to indicate impaired left ventricular relaxation.

Adolescent↗
PubMed2001

Serial changes of cardiac troponin-I in acute myoischemia induced by exercise treadmill test.

Cardiac troponin-I (cTn-I) is a sensitive and specific marker for the diagnosis of acute myocardial infarction (AMI). However, elevation of serum cTn-I has been observed in some unstable angina patients who have a worse prognosis than those with normal serum cTn-I levels. It is unknown whether serum cTn-I can elevate in stable angina patients with acute ischemic burden. Therefore, the purpose of this study was to determine a serial change of cTn-I in patients with acute ischemia induced by a treadmill exercise test. Thirty-five patients suspected of having coronary artery disease and five healthy medical students were enrolled into this study. Every patient received a treadmill exercise test. Cardiac troponin-I was measured by fluorescent immunoassay before the treadmill test and at 5 minutes, 1 hour, 3 hours, and 6 hours after the treadmill test. Patients with cTn-I levels of less than 0.5 ng/ml were considered normal, and those with cTn-I levels of greater than 2.0 ng/ml was considered to have AMI. The exercise test was positive in 19 of the 35 patients and negative in 16 of the 35 patients and 5 medical students. Among the 19 patients with positive treadmill exercise test, the cTn-I concentrations were abnormally increased in 7/19 (37%) patients (mean: 1.1 +/- 0.4 ng/ml; range: 0.5 to 2.0 ng/ml). One of the 16 patients with negative treadmill test showed an increase of serum cTn-I. Normal cTn-I levels were found in the other 15 patients and the 5 medical students. In conclusion, serum cTn-I levels were found to increase to some extent in one third of stable angina patients who have an acute ischemic episode induced by treadmill exercise test.

Aged↗
PubMed2001

Atrioventricular block in Kearns-Sayre syndrome: a case report.

The Kearns-Sayre (K-S) syndrome which includes the triad of progressive external ophthalmoplegia, pigment retinopathy, and disorder of cardiac conduction was first described in 1958. The mitochondria disorder is believed to be the cause of this syndrome. Involvement of the cardiac conduction system is the most importent prognostic factor in K-S syndrome. A 34-year-old male K-S syndrome patient, manifesting as ptosis and weakness of limbs since the age of 15 years, suffered from dizziness and weakness. Twelve-lead eletrocardiography (ECG) showed a 2:1 atrioventricular (AV) block with slow ventricular rate. Intermittent complete AV block, complete left bundle branch block and torsades de pointes were noted in Holter ECG. The electrophysiology study demonstrated prolonged HV interval (85 ms) on conduction beat and infra-His block on non-conduction beat. A VVIR mode of permanent pacemaker was implanted and the patient's condition was stable during this period of follow-up.

Adult↗
PubMed2001

Effect of ionic and nonionic contrast media on fibrinolysis in patients undergoing angiocardiography.

Very few investigators have studied the effect of contrast media on fibrinolysis. The results of those previous studies are contradictory and inconclusive. The purpose of this study was to evaluate the effect of ionic and nonionic contrast media on fibrinolysis in patients undergoing angiocardiography. Sixty-two patients randomly received either ionic contrast medium Hypaque-76 (n = 31) or nonionic contrast medium Ultravist-370 (n = 31). Plasma tissue plasminogen activator (t-PA), plasminogen activator inhibitor 1 (PAI-1), fibrinogen, and D-dimer were measured before and 20 minutes after the procedures. A significant increase of PAI-1 levels was seen in the Ultravist group but not in the Hypaque group. The t-PA and fibrinogen levels remained virtually unchanged in both groups. A significant increase of D-dimer concentrations was observed in the Hypaque group but not in the Ultravist group. The results of this study may in part explain the reason that the ionic contrast media produce fewer thromboembolic complications than the nonionic contrast media during the cardiac catheterization.

Adult↗
PubMed2001

Cystic left atrium myxoma--a rare case report.

Myxoma is the most common primary tumor of heart. The typical picture of myxoma under echocardiography is a solid, dense echo mass and left atrium is the most common site to find it. The cystic form of myxoma is vary rare. We report a patient who received echocardiographic examination under impression of mitral valve stenosis. A multilobulated cystic mass which was like a hydatid cyst was found in the left atrium and atrioventricular flow was affected by this mass. After tumor resection, myxoma with internal hemorrhage was proved by pathology. No further recurrent myxoma was found during follow-up echocardiographic examination.

Aged↗
PubMed2000

The effect of fluvastatin on fibrinolytic factors in patients with hypercholesterolemia.

Several studies have shown cardiovascular benefit in treating hypercholesterolemia with HMG-CoA reductase inhibitor. However, in addition to the lowering of cholesterol, the beneficial effects of this inhibitor reflect other pharmacological activities. Whether these beneficial effects are partly mediated by changes in fibrinolytic factors remains to be proven, since clinical studies on the effects of HMG-CoA reductase inhibitors on fibrinolytic factors have not yielded consistent results. The purpose of this study was to evaluate the effects of fluvastatin on fibrinolytic factors in hypercholesterolemic patients. After 6 weeks on a low-fat, low-cholesterol diet, 23 outpatients known to have primary hypercholesterolemia with low density lipoprotein cholesterol (LDL-C) > or = 130 mg/dl with at least 2 risk factors or fasting LDL-C > or = 160 mg/dl were selected for the study. Venous blood samples were collected at baseline and at 8 weeks after fluvastatin therapy (40 mg/day) to measure of tissue plasminogen activator (t-PA), plasminogen activators inhibitor-1 (PAI-1), fibrinogen, D-dimer and lipid profile. After 8 weeks of therapy, fluvastatin reduced serum cholesterol by 11% (261.9 mg/dl vs 233.2 mg/dl, P < 0.01) and LDL-C by 22% (191.9 mg/dl vs 149.3 mg/dl, P < 0.01). D-dimer was significantly decreased (0.38 ng/L vs 0.28 ng/L, P = 0.02) and tPA, PAI-1 and fibrinogen tended to decrease after therapy. Fluvastatin therapy improved fibrinolytic profile; the result of this study may in part explain the benefit of HMG-CoA reductase inhibitor on cardiovascular system other than lipid lowering.

Aged↗
PubMed1998

The probability of diagnosis of nasopharyngeal carcinoma in patients with only adult-onset otitis media with effusion.

This study tried to assess the probability of nasopharyngeal carcinoma (NPC) being present in adults with only otitis media with effusion (OME) and evaluate the necessity of nasopharyngeal biopsy in Taiwanese adults with only OME. The clinical features of patients with known OME were analyzed and the incidence of nasopharyngeal carcinoma in adults with only OME was assessed. The clinical features of 36 adults with OME but without other symptoms and signs suggestive of NPC who presented to the Kaohsiung Medical College Hospital Department of Otorhinolaryngology between December 1995 and February 1997 were analyzed. Two of these patients had biopsy-proven non-keratinizing carcinomas. OME was caused by upper respiratory infection in 8 patients (22.2%), chronic paranasal sinusitis in 5 (13.9%), allergic rhinitis in 5 (13.9%), NPC in 2 (5.6%), other etiologies in 5 (13.9%) and by unknown etiologies in 11 (30.5%). The incidence of NPC in adults with OME but no other symptoms and signs suggestive of NPC was 5.6% (2 out of 36 patients). It was higher than other reports because NPC has a high prevalence in Taiwan. Therefore, biopsy of the post-nasal space in adults with only OME when NPC is strongly suspected is necessary for the early diagnosis of NPC in Taiwan. We conclude that Taiwanese adults with only OME for which the cause is unclear should be subjected to an examination and biopsy of the nasopharynx to exclude NPC.

Adult↗
PubMed1997

Differential effects of adenosine on antegrade and retrograde fast pathway conduction in atrioventricular nodal reentry.

Although adenosine depresses antegrade atrioventricular (AV) nodal conduction, the effects of adenosine on antegrade and retrograde fast pathway conduction in AV nodal reentry have not been determined. In 17 patients (five men, 12 women, mean age 49 +/- 12 years) with common slow-fast AV nodal reentrant tachycardia, the antegrade slow pathway conduction was selectively and completely ablated by radiofrequency catheter ablation while the antegrade and retrograde fast pathway conduction remained intact. During high right atrial pacing at a mean pacing cycle length of 474 +/- 36 msec, adenosine was rapidly injected intravenously at an initial dose of 0.5 mg followed by stepwise increases of 0.5 mg or 1.0 mg given at 5-minute intervals until second-degree AV block developed. During right ventricular apical pacing at the same pacing cycle lengths (mean 474 +/- 36 msec) as those in the study of antegrade conduction, intravenous injection of incremental doses of adenosine was repeated until ventriculoatrial (VA) block occurred. The adenosine-induced prolongation of VA conduction was also determined in the presence of verapamil (loading dose 0.15 mg/kg, maintenance dose 0.005 mg/kg/min) in seven of 17 patients. The dose of adenosine required to produce AV block, the increase in the atrio-His interval by 50% and the maximal response were 3.4 +/- 1.4 mg, 1.8 +/- 0.6 mg, and 58% +/- 5%, respectively. On the other hand, the dose of adenosine required to produce VA block, the increase in the VA interval by 50%, and the maximal response were 8.2 +/- 2.9 mg, 3.4 +/- 0.6 mg, and 20% +/- 5%, respectively, in the control and 3.7 +/- 0.5 mg, 3.5 +/- 0.7 mg, and 23% +/- 5%, respectively, in the presence of verapamil. In conclusion, adenosine has a differential potency to depress AV and VA conduction in patients with AV nodal reentry, with greater potency for slowing antegrade fast than retrograde fast pathway conduction. Verapamil had an additive effect to adenosine on slowing retrograde VA conduction, which further supports the evidence that the retrograde fast pathway in part involves an AV nodal-like structure.

Adenosine↗
PubMed1996

Effects of verapamil, propranolol, and procainamide on adenosine-induced negative dromotropism in human beings.

Adenosine, verapamil, propranolol, and procainamide are widely used antiarrhythmic drugs. The interactions among them are still not known in human beings. Adenosine-induced negative dromotropic effects were assessed by rapid bolus injection of adenosine during constant high right atrial pacing in each patient. The initial dose of adenosine was 0.5 mg and was followed by a stepwise increment of 0.5 mg until atrioventricular (AV) nodal block occurred. The negative dromotropic actions of adenosine were examined in the control state and in the following three protocols in three groups of patients: (1) In 12 patients (group 1), intravenous verapamil, 0.15 mg/kg, was given; (2) In 12 patients (group 2), intravenous propranolol, 0.1 mg/kg, was given; and (3) in 10 patients (group 3), intravenous procainamide, 15 mg/kg, was given. The dose-response curves of adenosine on AV nodal conduction were almost identical in the control state and after verapamil, propranolol, or procainamide injection. However, verapamil, in contrast to propranolol, significantly reduced the dose of adenosine required to produce AV nodal block, from 4.4 +/- 0.7 mg to 2.7 +/- 0.3 mg (p < 0.01). Of note, procainamide exerted no significant effects on adenosine-induced negative dromotropism on AV nodal conduction or AV nodal block. In conclusion, the negative dromotropic effects of adenosine are preserved and independent even in the presence of verapamil, propranolol, or procainamide. Both verapamil and propranolol can exhibit additive effects with adenosine in prolonging AV nodal conduction time; however, only verapamil can reduce the dose of adenosine required to produce AV nodal block. This finding indicates that the dose of adenosine may be reduced for patients who have already been treated with verapamil.

Adenosine↗
PubMed1996

Capsinolol: the first beta-adrenoceptor blocker with an associated calcitonin gene-related peptide releasing activity in the heart.

1. The beta-adrenoceptor blocking and calcitonin gene-related peptide (CGRP)-releasing properties of capsinolol (N-[4-(2-hydroxy-3 (isopropylamino) propoxy)-3-methoxybenzyl]-nonanamide), derived from nonivamide, were investigated under in vivo and in vitro conditions. 2. Capsinolol (0.1, 0.5, 1.0 mg kg-1, i.v.), as well as (+/-)-propranolol, produced a dose-dependent bradycardia response and a temporary pressor action in urethane-anaesthetized normotensive Wistar rats. These cardiovascular effects were different from the vagus reflex and parasympathetic efferent effects shown by capsaicin (0.1 mg kg-1, i.v.) in the rat. 3. Capsinolol (1.0 mg kg-1) inhibited the tachycardia effects induced by (-)-isoprenaline, but had no blocking effect on the arterial pressor responses induced by (-)-phenylephrine. The findings suggest that capsinolol possesses beta-adrenoceptor blocking activity, but it has no alpha-adrenoceptor blocking activity. 4. In guinea-pig isolated tissues, capsinolol (10(-8) to 10(-6) M) antagonized (-)-isoprenaline-induced positive chronotropic and inotropic effects of the atria and tracheal relaxation responses in a concentration-dependent manner. The parallel shift to the right of the concentration-response curve of (-)-isoprenaline suggests capsinolol is a beta-adrenoceptor competitive antagonist. 5. Capsinolol (10(-5) to 10(-4) M) exhibited a positive cardiotonic effect that was not inhibited by (+/-)-propranolol and reserpine, but was inhibited by capsazepine (10(-6) M) and CGRP8-37 (10(-6) M). This effect was independent of intrinsic sympathomimetic effects. 6. An immunoassay of released CGRP from guinea-pig isolated perfused heart indicated that capsinolol increases the release of CGRP and thus produces positive cardiotonic effects. 7. In conclusion, capsinolol is a non-selective beta-adrenoceptor antagonist with capsaicin-like cardiotonic properties unrelated to traditional intrinsic sympathomimetic effects. It is suggested that capsinolol causes CGRP release from cardiac sensory neurones via a non-adrenergic mechanism and then activates CGRP receptors on cardiac muscle.

Adrenergic beta-1 Receptor Antagonists↗
PubMed1995

Electrophysiological manifestations of the excitable gap of slow-fast AV nodal reentrant tachycardia demonstrated by single extrastimulation.

BACKGROUND: Although AV nodal reentrant tachycardia (AVNRT) is a well-known rhythm disorder, its anatomic substrate and electrophysiological mechanism remain to be defined. Previously, the description of the excitable gap (EG) of AVNRT was based on electrical stimulation performed from sites remote from the reentrant circuit. In the present study, we characterized the EG of AVNRT by atrial extrastimulation close to the putative reentrant circuit in the AV junction. METHODS AND RESULTS: In 16 patients (3 men, 13 women; mean age, 45 +/- 13 years) with inducible slow-fast AVNRT (mean cycle length, 353 +/- 52 ms), single extrastimuli with a 10-ms decrement in the premature coupling interval were delivered from the anterosuperior interatrial septum (fast pathway area) and the posteroinferior interatrial septum (slow pathway area) from late diastole until atrial refractoriness. An EG was considered present when resetting or termination of AVNRT was induced by single atrial extrastimulation. The study showed that the duration of the EG of AVNRT was wide, measuring 121 +/- 56 and 123 +/- 47 ms and occupying 33 +/- 11% and 34 +/- 9% of the tachycardia cycle length during single extrastimulation from the slow pathway area and the fast pathway area, respectively. The resetting pattern most commonly manifested as the sum of the coupling interval and the return cycle being less than a fully compensatory pause (two times the basic tachycardia cycle length). However, patterns equal to and greater than a fully compensatory pause were also observed. Of note, in 2 of the 16 patients, atrial extrastimulation from either the fast or slow pathway area also affected the preceding tachycardia cycle length (HH interval), indicating alteration of the anterograde input. In all patients, the curve derived from plotting the coupling interval of extrastimuli against the return cycle during resetting exhibited an "increasing" pattern. The mode of tachycardia termination usually occurred when the premature atrial impulse was orthodromically blocked in the anterograde slow pathway. CONCLUSIONS: The EG of slow-fast AVNRT is relatively wide, as demonstrated by single atrial extrastimulation from the interatrial septum near the AV junction. Overall, the electrophysiological manifestations of the EG of AVNRT are very similar to those described in AV reciprocating tachycardia incorporating an accessory connection. These findings lend further support to the notion that, in humans, AVNRT involves a reentrant mechanism with a wide excitable gap.

Adolescent↗