Biomedical subjects

Shu-Chiung Chiang

Publications and source records attributed to Shu-Chiung Chiang.

8 recordsLinked to original sources

PubMed2004

Brief pressure overload of the left ventricle preconditions rabbit myocardium against infarction.

BACKGROUND: Several nonischemic stimuli have been shown to precondition myocardium. We investigated cardioprotective effects and underlying mechanisms of brief pressure overload of the left ventricle in this study. METHODS: Brief pressure overload of the left ventricle was achieved by two 10-minute partial snaring of the ascending aorta so that systolic left ventricular pressure was raised 50% above the baseline value. Ischemic preconditioning was elicited by two 10-minute coronary artery occlusions. Ten minutes after different pretreatments, myocardial infarction was induced by a 60-minute coronary artery occlusion followed by 3-hour reperfusion. Area at risk and myocardial infarct was determined by blue dye injection and triphenyl tetrazolium chloride staining. RESULTS: The myocardial infarct size, expressed as percentage of area at risk, was significantly reduced in the pressure overload group (15.9% +/- 2.9%, p < 0.001, n = 9) as well as in the ischemic preconditioning group (14.9% +/- 1.9%, p < 0.001, n = 9) versus the control group (30.0% +/- 6.9%, n = 10). Pretreatment with a blocker of stretch-activated ion channels (gadolinium, 40 micromol/kg, intravenous) abolished the protection induced by pressure overload and ischemic preconditioning. Gadolinium itself did not alter the extent of infarct. There was no significant difference in hemodynamics, area at risk, and mortality among all groups of animals. CONCLUSIONS: Brief pressure overload of the left ventricle by partial snaring of the ascending aorta preconditioned rabbit myocardium against infarction. The underlying mechanism might be related to activation of stretch-activated ion channels.

Animals↗

PubMed2004

A simple, safe, and efficient way to treat severe fluoride poisoning--oral calcium or magnesium.

PURPOSE: To examine the efficacy and safety of administration of calcium and magnesium orally and intraperitoneally to treat severe sodium fluoride intoxication. MATERIALS AND METHODS: Mice were initially gavaged a lethal dose of sodium fluoride (NaF) or water. Then, mice were treated with water or varying concentrations of calcium chloride (CaCl2) or magnesium sulfate (MgSO4) via intraperitoneal (IP) route or via oral route. Mice were monitored for 24 h, and the time of death was recorded. RESULTS: IP injections of large amounts of CaCl2 or MgSO4 were dangerous. All mice gavaged with water and then treated with oral CaCl2 or MgSO4 survived and displayed normal activity during the experiment. The survival rate of mice gavaged with a lethal dose of NaF and then treated with a high dose of oral CaCl2 or MgSO4 was significantly higher than those of using low dose. CONCLUSION: Oral administration of a high dose of CaCl2 or MgSO4 is a simple, safe, and effective adjunctive method for treating severe oral fluoride poisoning.

Administration, Oral↗

PubMed2004

The value of plasma levels of tumor necrosis factor-alpha and interleukin-6 in predicting the severity and prognosis in patients with congestive heart failure.

BACKGROUND: High plasma levels of pro-inflammatory cytokines play an important role in the pathophysiology of congestive heart failure (CHF). Therefore, we conducted a case-control study to determine the correlations between plasma levels of cytokines, i.e., tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6, and the severity and mortality in patients with CHF. METHODS: One-hundred and 18 cases (62+/-15 years old) were classified into 3 groups: group 1 comprised 44 control cases with normal coronary arteriogram and left ventriculography and without valvular disorders or cardiomyopathy; group 2 comprised of 37 cases with mild CHF in New York Heart Association (NYHA) functional class (FC) II; group 3 had 37 cases with moderate/severe CHF in NYHA FC III or IV. Pre-catheterization plasma levels of TNF-alpha and IL-6 along with clinical and hemodynamic variables and follow-up data of cardiac death were assessed. RESULTS: Patients of group 3 had smaller body mass index, lower systolic and diastolic blood pressures, faster heart rates, higher left ventricular end-diastolic pressure and lowered triglyceride levels than the patients of groups 1 and 2. The plasma levels of TNF-alpha and IL-6 increased significantly in patients of group 3 in comparison with patients of groups 1 and 2 (both p < 0.001). Over the following 1.5 years, 13 patients died. Univariate analysis identified the following variables to be associated with poor prognosis: NYHA FC (p < 0.001), plasma TNF-alpha (p = 0.013), plasma IL-6 (p < 0.001), systolic blood pressure (p = 0.001), heart rate (p = 0.045) and left ventricular end-diastolic pressure (p = 0.021). Multivariate Cox regression analysis identified the independent predictors of cardiac death as FC (p = 0.007) and plasma IL-6 (p = 0.021). CONCLUSIONS: Our findings indicate that the plasma levels of IL-6 and TNF-alpha and especially the former, is a useful marker to correlate the progression of severity and late cardiac death in patients with CHF.

Aged↗

PubMed2002

The comparison of electrophysiologic findings of traumatic brachial plexopathies in a tertiary care center.

This study was undertaken to demonstrate the distribution of causative factors of brachial plexopathy (BP), to assess the association between the mechanism of injuries and the predominant level of the brachial plexus involved in the injuries, and to characterize the extent and degree of severity of injury in patients with BPI. It consisted of a cross-sectional, retrospective review of electrophysiological data of 5547 patients with 117 patients being identified as having BPI, of whom 86 patients were recruited into the study. The patients were divided into six subgroups according to the mechanism of the damage. The injury was subdivided according to the brachial plexus levels predominantly affected, and each component of the four major anatomical plexus levels-root, trunk, cord and nerve levels was analyzed. The affiliation between the type of injuries and the specified brachial plexus levels was calculated via a two-tailed Fisher's exact test. These findings demonstrated that the type of brachial plexus injury (BPI) is significantly related to the brachial plexus level involved. The motorcycle and birth injury groups were affected at the trunk level, the fall group at the nerve level, the automobile group at the cord level, and the blunt injury group at the cord or nerve level. Moreover, the majority of patients in the motorcycle, fall, and pedestrian groups suffered from severe, incomplete lesions, while the neurophysiological results of the other groups varied.

Accidents, Traffic↗

PubMed2002

A virtual reality-based system for hand function analysis.

The goal of this study was to demonstrate the usability and usefulness of virtual reality technology in assessing hand functions. Ten healthy, non-disabled right-handed adult volunteers were recruited. Each volunteer used a dataglove to insert three-dimensional virtual representations of a cylinder and a prism into the target holes. To verify the reliability of the tests, each subject was retested twice. The performance testing assessed the visual-motor coordination a person needs to achieve a task accurately and within a set time. For each trial, the root mean square (RMS) value of the hand movement trajectory was projected onto the X, Y, and Z axes. This projection enabled us to measure the extent of the genuine, summative displacement of the manipulating hand. The reproducibility of the virtual reality assessment was analyzed using the intraclass correlation (ICC) approach. The total ICC values of 10 subjects demonstrated a high task completion time and RMS on the X and Z axes for the transferring of the prism. However, the values were low for the transferring of the cylinder. Because the individual coefficients of variations (CVs) varied widely in the moving of both the cylinder and the prism, the total (CVs) showed a high reading for the task completion time. Although rehabilitation clinics routinely carry out peg-moving exercises for disabled patients, our model provides a valuable quantitative real time and off-line measure of whole hand functions.

Adult↗

PubMed2002

Use of latanoprost to reduce acute intraocular pressure rise following neodymium: Yag laser iridotomy.

PURPOSE: To evaluate the efficacy of latanoprost in reducing acute intraocular pressure (IOP) elevation after neodymium:Yag laser iridotomy (LI). METHODS: Primary angle-closure glaucoma (PACG) eyes were randomized to receive premedication with latanoprost and pilocarpine or with pilocarpine only before LI. Postoperative IOP changes were compared with Wilcoxon signed-ranks test using the fellow eyes of 47 patients who had one eye in each group. RESULTS: Postoperative pressure spikes were significantly lower (p = 0.010) in the latanoprost group (4.1 +/- 5.0 mmHg) than in the control group (6.7 +/- 7.0 mmHg). Mean elevation of IOP was less in the latanoprost group than in the control group at 1 hour (2.5 +/- 4.8 versus 4.1 +/- 4.7 mmHg, p = 0.013) and 2 hours (0.8 +/- 5.6 versus 4.4 +/- 8.1 mmHg, p = 0.003) postoperatively. Eleven eyes in the latanoprost group (23.4%) and 20 eyes in the control group (42.6%) developed a rise in IOP > or = 6 mmHg (p = 0.048). CONCLUSION: Latanoprost may reduce the pressure rise following LI in PACG eyes, but its application is limited by a late onset of effect.

Acute Disease↗

PubMed2002

The risk of coronary artery disease in population of Taiwan is associated with Cys-Ser 311 polymorphism of human paraoxonase (PON)-2 gene.

BACKGROUND: Paraoxonase (PON), a high density lipoprotein (HDL)-associated enzyme, is capable of inhibiting low density lipoprotein (LDL) oxidation by destroying the biologically active phospholipids in oxidatively modified LDL. An increased risk of coronary artery disease (CAD) has shown to associate with polymorphisms of PON gene (PON1) in different population. The risk of CAD associated with the other PON1-like gene, designated PON2, which has a similar function and is structurally related to PON1, is least discussed. A population-based case-control study was conducted to investigate the association between CAD and the polymorphisms at two common codons 148 and 311 of PON2 in the population of Taiwan. METHODS: Totally 364 unrelated, angiographically proved CAD-positive patients (338 male and 26 female) and 337 unrelated, CAD-free control subjects (249 male and 88 female) enrolled in this study. Lipids and lipoproteins profile and the association of PON2 genotypes and allele frequencies were analyzed in all study cohorts. RESULTS: The plasma levels of HDL-cholesterol and apoA-I were significantly lower in patients with CAD than in control subjects (both p = 0.0001). There was no difference in the genotype frequency distribution at codon 148 of PON2 between CAD patients and the controls. However, age-, sex- and diabetes-adjusted odds ratios for individuals with the SS genotype of the codon 311 polymorphism (Cys --> Ser, PON2*C allele --> PON2*S allele) showed a 4.6-fold higher risk of CAD (95% CI = 1.6-15.3, p = 0.006) they ran. Also, in the control subjects, PON2*C allele carriers (CC and CS genotypes) had higher plasma levels of HDL than cases with the SS genotypes (p = 0.035 and p = 0.012, respectively). CONCLUSIONS: Our data implicate that the genotypic variation at codon 311 of PON2 contributes to the susceptibility of CAD in the population of Taiwan.

Adult↗

PubMed2002

Fentanyl-induced coughing and airway hyperresponsiveness.

BACKGROUND: The tussive effect of fentanyl, in sharp contrast to the antitussive effect that common opioids have, is not rarely seen in clinical anesthesia. Pretreatment with beta 2 agonist inhalation could dramatically suppress fentanyl-induced coughing. We hypothesized that airway hyperresponsiveness might exist in large proportion of the subjects who had experienced fentanyl-induced coughing during previous anesthesia. METHODS: We designed a case-controlled matching study to investigate the correlation between fentanyl-induced coughing and airway hyperresponsiveness. Twenty-six consecutive subjects (ASA I-III), who experienced fentanyl-induced coughing during anesthesia in our hospital from 1999 to 2000, were enrolled in this study as the fentanyl-cough group. In all the subjects baseline spirometry was first obtained. Airway responsiveness was evaluated with either PC20 of methacholine challenge test or bronchodilator test. After matching age and sex, another 26 subjects without history of fentanyl-induced coughing during previous anesthesia were also enrolled in the study as the control group. RESULTS: The proportion of airway hyperresponsiveness in fentanyl-cough group and control group was 30.77% and 19.23% respectively. After pairing of these two groups, McNemar test revealed no significant difference in the proportion of airway hyperresponsiveness between these two groups (P = 0.257). CONCLUSIONS: From the analysis of the present study, we cannot prove that there is a direct correlation between fentanyl-induced coughing and airway hyperresponsiveness.

Adolescent↗