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Biomedical subjects

J B Chang

Publications and source records attributed to J B Chang.

At least 19 recordsLinked to original sources
PubMed2004

ApoE epsilon4 allele is associated with incidental hallucinations and delusions in patients with AD.

Of 135 patients with Alzheimer disease (AD), 56 without psychiatric symptoms at the first visit were followed for a mean period of 51.9 +/- 10.3 months to identify incident psychiatric symptoms. The hazard ratios of ApoE epsilon4 allele in developing psychiatric symptoms were calculated by Cox regression hazard analyses. The presence of the ApoE epsilon4 allele carried a 19.0-fold risk for developing hallucinations and a 3.4-fold risk for delusions.

Aged↗
PubMed2003

The effect of surgical stress on insulin sensitivity, glucose effectiveness and acute insulin response to glucose load.

Hyperglycemia after stress is a very common clinical phenomenon. It is generally hypothesized that the underlying cause is a neuroendocrine-mediated deterioration in glucose metabolism. However, the detailed roles of insulin sensitivity, glucose effectiveness and acute insulin response to glucose load in response to stress have not been well established. Hernioplasty was used as a minor stress model for studying stress-induced hyperglycemia. Eleven healthy young men were enrolled voluntarily in this study. Their mean age was 22.0 +/- 0.9 yr and BMI 23.3 +/- 0.6 kg/m2. Frequently sampled i.v. glucose tolerance tests were performed one day before and one day after the surgery. Insulin sensitivity (SI), glucose effectiveness (EG) and area under acute insulin response (AIR) were calculated from "minimal model" algorithms. We also measured fasting concentrations of human GH, ACTH and F on the days of the test. Compared to the pre-operation data, levels of ACTH and F did not change significantly after the surgery. Only GH levels were marginally significant. On the other hand, the SI (0.75 +/- 0.1, 0.52 +/- 0.9 x 10(-5) min(-1)/pmol, p = 0.04), EG (0.023 +/- 0.03, 0.016 +/- 0.003 min(-1), p = 0.01) and AIR (6738.5 +/- 1111.6, 5130.0 +/- 1047.2 pmol, p = 0.005) were all significantly decreased after surgery. The percentages of decrease were 16.3 +/- 15.5, 32.1 +/- 10.3 and 17.8 +/- 10.3%, respectively. Finally, only the changes of EG positively correlate with the changes of ACTH before and after surgery. No significant changes were noted among other stress hormones and the changes of SI, EG and AIR. In conclusion, hernioplasty results in reduced SI, EG and AIR. Among them, although not statistically significant, the EG showed the most distinct decrease after the surgery, which has not been found in previous literature.

Adolescent↗
PubMed2003

Determinants and distributions of plasma total homocysteine concentrations among school children in Taiwan.

BACKGROUND: Plasma total homocysteine (tHcy) level is an independent risk factor for cardiovascular disease (CVD) even among children. The purpose of this study is to evaluate the determinants and distributions of plasma tHcy levels and the relationship between plasma tHcy, folate and vitamin B12 levels among school children in Taipei. METHODS: After multi-stage sampling, we randomly selected 1234 school children (609 boys and 625 girls) with the mean age of 13 years (from 12 to 15 years) in this study. Fasting plasma tHcy levels were measured using an ABBOTT IMx analyzer (Axis Biochemicals ASA, Oslo, Norway). Plasma folate and vitamin B12 levels were measured by ACS:180 automated chemiluminescence analyzer (Bayer, Tarrytown, NY, USA). RESULTS: The distribution of plasma tHcy levels were skewed to the right with the mean values of 10.50 and 8.95 micromol/l and medians of 9.67 and 8.474 micromol/l for boys and girls, respectively. Plasma tHcy concentrations were lower in younger children and progressively increased with increasing age. Boys had significantly higher plasma tHcy levels than girls (10.50 +/- 4.134 vs. 8.95 +/- 2.61 micromol/l, p < 0.01) and lower plasma folate levels (6.05 +/- 2.85 vs. 6.39 +/- 2.58 nmol/l, p < 0.01), and vitamin B12 levels (444.8 +/- 158.4 vs. 495.0 +/- 181.5 pmol/l, p < 0.001). Plasma tHcy levels were significantly positively associated with anthropometric measures in boys; but these characteristics attenuated and became insignificant after adjusting for other potential confounders in girls. Plasma tHcy levels were negatively associated with plasma folate and vitamin B12 levels even after adjusting for BMI and other potential confounders in both genders. CONCLUSIONS: From this study, the distributions of tHcy levels were skewed to the right and the boys had higher plasma tHcy levels than girls. Plasma tHcy levels were significantly positively associated with BMI among boys. Further studies are needed to evaluate the relationship between tHcy and CVD risk factors among children for the better prevention of heart disease in early life.

Adolescent↗
PubMed2001

Infrainguinal revascularizations in octogenarians and septuagenarians.

OBJECTIVE: Severe atherosclerosis is a major contributor for death in octogenarians and a cause of multiple vascular-related ailments, including claudication and limb loss. Advanced age and health may limit the success of limb-salvaging procedures. Mortality, morbidity, and outcome of infrainguinal grafts have been examined in octogenarians and septuagenarians. METHODS: After 128 femoropopliteal and 99 femorotibial bypass grafts in 209 octogenarians and 242 femoropopliteal and 166 femorotibial bypass grafts in 383 septuagenarians, survival, primary patency, limb salvage, myocardial infarction and stroke rates were determined. The survival, myocardial infarction, and stroke rates of controls, 1514 octogenarians and 2011 septuagenarians, were compared. RESULTS: After a bypass graft, 5-year survival of octogenarians (54%) and septuagenarians (64%) was similar (P >.2) and was 89% and 89% for controls. The 5-year primary patency rates were 74% for octogenarians and 68% for septuagenarians (P >.2). Five-year limb salvage rates were 86% for octogenarians and 86% for septuagenarians. After a bypass graft, the respective rates of myocardial infarction were 4.1% and 3.9% per year and of a stroke 3.2% and 3.2% per year for octogenarians and septuagenarians, which occurred more frequently (P <.05) than in controls. CONCLUSIONS: Death and cardiovascular events are higher after revascularization in octogenarians and septuagenarians, compared with controls, and are related to the severity of atherosclerosis and not age. Patency rates are excellent and similar. Limb salvage procedures should be considered for most octogenarians.

Aged↗
PubMed2001

Spread of 60Co contaminated steel and its legal consequences in Taiwan.

Since 1992, over 200 civilian residential and school buildings in Taiwan have been identified to have contained 60Co contaminated steel rebar emitting excessive gamma-radioactivity in living environments. These buildings were mostly constructed in early 1983 and 1984 by employing steels from one steel mill, which had recycled unknown 60Co orphan sources in northern Taiwan. In 1994, a group of residents who once stayed for a protracted period up to 10 y in the contaminated Ming-Sheng Villa filed a civil action against Taiwan's nuclear regulatory office, the Atomic Energy Council, for state tort compensation of 3.4 M U.S. dollars in equivalent. After three years of court processes, the Taipei District Court handed down a decision in partial favor of the exposed residents. Both parties soon appealed against this judgment to the Taiwan Appellate Court. This article analyzes the main legal issues involved, including government's obligations to prevent and eliminate contamination, to take preventive measures, and to take necessary remedial measures; and plaintiffs' assertion on any legal right against governmental offices. Moreover, discussion issues contain the scope of damage and compensation, causation analysis, absence of effective and efficient regulation over radioactive contamination, limit of tort compensation law and compensation amount, weight of medical evidence as well as role of expert witnesses, and related comparative legal studies.

Cobalt Radioisotopes↗
PubMed2000

Lipoprotein profiles, not anthropometric measures, correlate with serum lipoprotein(a) values in children: the Taipei children heart study.

OBJECTIVE: Plasma lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease. The purpose of this study is to evaluate the correlation of anthropometric measures, lipids and lipoprotein profiles and serum Lp(a) values among children in Taiwan. We will attempt to find parameters that will be able to predict Lp(a) levels in children. DESIGN AND METHODS: After a probability-proportional-to size, multi-stages sampling procedure, we randomly sampled 1500 schoolchildren from 10 schools in Taipei city. Anthropometric measures including body weight, body height, waist and hip circumference and skinfolds were measured. We used standard methods to measure serum total cholesterol (CHOL), triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), apolipoprotein A1 and B (ApoA1 and ApoB) and Lp(a) levels. We also calculated low density lipoprotein-cholesterol (LDL-C) and CHOL HDL-C ratio (TCHR) by formula. RESULTS: We sampled 1283 children (635 boys and 648 girls) with a mean age of 13.3 years (from 12 to 16 years) in this study. The mean and medium serum Lp(a) levels were 16.8 and 8.8 mg/dl among boys and 20.8 and 11.9 mg/dl among girls. Children in the highest quintile of Lp(a) (mean = 49.6 and 58.6 mg/dl for boys and girls, respectively) had higher CHOL, LDL-C, ApoB levels and TCHR than children in the lowest quintile (mean = 3.1 and 3.7 mg/dl for boys and girls, respectively). Lipids and lipoprotein profiles, such as CHOL, LDL-C, Apo-B and TCHR were positively correlated with Lp(a) levels in both genders. Furthermore, the children with Lp(a) levels greater than or equal to 30 mg/dl had higher CHOL, LDL-C and Apo-B levels when compared to children with Lp(a) levels less than 30 mg/dl. After adjusting for age, cigarette smoking, alcohol drinking, puberty development and heart rates, LDL-C and ApoB levels were significantly positively associated with Lp(a) levels while ApoA1 was negatively associated among boys. Among girls, only Apo-B was significantly positively associated with Lp(a) and TG was negatively associated with Lp(a) levels. Most importantly, none of the anthropometric measures were significantly correlated with Lp(a) levels. CONCLUSIONS: From this study, we found that lipids and lipoproteins profiles, rather than degree of adiposity as reflected by anthropometric measures, are significantly associated with serum Lp(a) levels among school children.

Adolescent↗
PubMed2000

Relationship between single voided urine protein/creatinine ratio and 24-hour urine protein excretion rate among children and adolescents in Taiwan.

BACKGROUND: As there have been few studies conducted on children or adolescents, the purpose of this study was evaluate the relationship between single voided urine protein/creatinine (Up/Ucr) ratio and 24-hour urine protein excretion rate (PER), especially among children and adolescents in Taiwan. METHODS: After multistage random sampling, we collected 1,072 fasting single voided urine samples and 125 24-hour urine samples from seven- to 18-year-old students in Taiwan. We calculated the Up/Ucr of single voided urine samples and the 24-hour PER in urine. RESULTS: The mean value and the 95th percentile of the fasting single voided urine Up/Ucr ratio were 0.118 and 0.235, respectively. The mean value and the 95th percentile of the 24-hour PER were 3.61 and 5.66 mg/h/m2, respectively. There was no significant difference in Up/Ucr ratio between boys and girls. Up/Ucr ratio decreased significantly as age increased. The fasting single voided Up/Ucr ratio was highly correlated with 24-hour PER, with r2 = 0.95 (p < 0.001). CONCLUSIONS: Fasting single voided Up/Ucr ratio is a good marker of 24-hour PER. It is also a simple, easy, convenient and speedy method to measure Up excretion. The single voided Up/Ucr ratio may also serve as a reference for the clinical diagnosis of Up excretion among normal subjects.

Adolescent↗
PubMed2000

[Direct optical resolution of acidic biphenyl drugs by high performance liquid chromatography on tris(3,5-dimethylphenylcarbamate) of cellulose].

A chiral stationary phase was prepared by coating cellulose-tris(3, 5-dimethylphenylcarbamate) onto aminopropylated silica gel. A series of enantiomeric acidic biphenyl drugs were directly resolved on the chiral stationary phase (CSP) by normal-phase high performance liquid chromatography (HPLC). A hexane-2-propanol eluting system containing 1% of trifluoroacetic acid was used as mobile phase. Efficient optical resolution of the acidic biphenyl drugs has been attained. The factors that influence chiral discrimination such as structural characeristic of the samples and mobile phase were investigated. An interaction model between the stationary phase and the samples was discussed. The results showed that efficient optical resolution of racemic carboxylic acids could be attained by normal-phase HPLC on CSP using a hexane-2-propanol eluting system containing 1% of trifluoroacetic acid.

Carbamates↗
PubMed2000

[Analysis of imidacloprid and damanlin by high performance liquid chromatography].

A new method for determination of imidacloprid and damanlin by using HPLC was established. It was carried out on a mu Bondapak C18 column (3.9 mm i.d. x 300 mm) with ACN-MeOH-H2O (60:10:30, V/V) as eluent and detected at 240 nm using photodiode array detector. The results of imidacloprid and damanlin were 3.71% and 15.65% respectively. The standard deviations for imidacloprid and damanlin were 0.88% and 0.76% respectively.

Animals↗
PubMed1997

Late stroke in patients after carotid endarterectomy.

BACKGROUND: Some patients may be more predisposed to develop an ulceration of atherosclerotic plaque in the carotid artery, and emboli. These patients should be more at risk for a late stroke even after carotid endarterectomy than patients who are not. MATERIALS AND METHODS: Six-hundred thirty-eight patients had 750 carotid endarterectomies. Excised plaque specimens were examined for gross ulceration. The degree of stenosis was determined by duplex scan and/or angiography, and at operation. The median follow-up time was 3.6 years. The risk of a stroke occurring >30 days after carotid endarterectomy was calculated. Within 1 year, an endarterectomy of the contralateral artery was done in 77 patients (Subgroup) at a median time of 60 days. RESULTS: Late stroke occurred in 48 patients. Patients who had had ulcerated plaque had a stroke at a median time of 2.0 years, and patients who had had no ulcers had a stroke at a median time of 5.2 years (P < 0.025). The 14-year stroke-free curve was lower (P < 0.05) if there was plaque ulceration. In the Subgroup, plaque ulcers were found in 55 patients (71%) at the first endarterectomy and later in 46 of the 55 patients (84%) in the contralateral artery. No ulcers were found in 22 patients (29%) initially, but later 50% had ulcers in the contralateral artery. The risk of an ulcer in the contralateral artery was increased (P < 0. 005) in those patients who had ipsilateral carotid ulcers. CONCLUSIONS: Some patients appear to be predisposed for plaque ulceration and late stroke.

Aged↗
PubMed1997

Risk factors associated with rapid growth of small abdominal aortic aneurysms.

BACKGROUND: Approximately 50% of patients who have a ruptured abdominal aortic aneurysm will die. To identify those patients who may be at high risk for rupture, we determined the risk factors for the rapid expansion of the aorta. METHODS: The growth of 514 aneurysmal aortas was followed in this study. The size of each was measured by ultrasonography at 6- to 12-month intervals until a critical size was reached or a rapid expansion of the aorta occurred. Possible risk factors for rapid expansion were determined from both initial evaluation and clinical laboratory results. RESULTS: The initial size varied from 2.5 cm to 6.0 cm. The expansion rate of the aorta was 0.5 cm/yr or less in 401 patients (78%), between 0.5 and 1.0 cm/year in 50 patients (10%), and 1.0 cm/year or more (rapid expansion) in 63 patients (12%). Elective repair of aneurysms was done before rupture. Multivariate analysis indicated that the risk factors associated (p < 0.03) with rapid expansion were advanced age, severe cardiac disease, previous stroke, and history of cigarette smoking. The incidence for rapid expansion increased (p < 0.01) in older patients with aneurysms larger than 3 cm and in younger patients with aneurysms larger than 4 cm. CONCLUSIONS: Risk factors associated with rapid expansion of the aorta have been determined and may help identify the patient at high risk for rupture. Ultrasonographic surveillance should be performed more frequently in these patients to help prevent rupture.

Adult↗
PubMed1997

Long-term results with axillo-axillary bypass grafts for symptomatic subclavian artery insufficiency.

PURPOSE: The surgical treatment for patients with a subclavian steal is controversial, especially for patients with coexisting severe carotid stenosis. This study determines the long-term efficacy of axillo-axillary bypass grafts in patients with and without a simultaneous carotid endarterectomy. METHODS: The axillo-axillary bypass was done in 39 patients who were monitored for 5.8 +/- 3.9 years. Fifteen of these patients with severe carotid artery disease had a carotid endarterectomy done simultaneously. Twenty-four patients had an axillo-axillary bypass alone; four of these patients later had a carotid endarterectomy at 0.5 to 10 years. Graft patency was evaluated at intervals of 6 to 12 months by clinical evaluation and noninvasive vascular studies. RESULTS: Ten-year primary and secondary patency rates for all axillo-axillary bypass grafts were 88% and 91%, respectively. When carotid endarterectomy was done with axillo-axillary bypass, these patency rates were 86% and 93%, respectively. Patients with only axillo-axillary grafts had 10-year primary and secondary patency rates of 89% and 89%, respectively. Most patients had complete relief from symptoms of arm ischemia (90%) and vertebrobasilar insufficiency (85%). No perioperative mortality or permanent neurologic deficit occurred. CONCLUSIONS: Axillo-axillary bypass is a safe and effective method for revascularization of the subclavian artery and should be considered for patients at high risk.

Adult↗
PubMed1995

The long-term value of composite grafts for limb salvage.

PURPOSE: We determined the long-term efficacy of composite grafts for limb salvage when autogenous vein grafts were not available. METHODS: After arterial bypass, the 8-year primary and secondary patency, limb salvage, and mortality rates were compared by life-table analysis. One hundred twenty-five patients had 130 composite grafts for 27 femoropopliteal bypasses, 48 femorotibial bypasses, and 55 sequential femoropopliteotibial bypasses. Three hundred forty patients had autogenous vein grafts for 247 femoropopliteal bypasses and 114 femorotibial bypasses. Seventy-two patients had 82 femoropopliteal prosthetic grafts. RESULTS: Eight-year primary and secondary patency rates were 56% and 62% for femoropopliteal procedures with composite grafts, respectively, and 53% and 59% for autogenous vein grafts, respectively. The secondary patency rate for polytetrafluoroethylene grafts was 35% and was less (p < 0.05) than the rate for the vein grafts. Secondary patency rates for femorotibial procedures were 66% for the vein grafts, 56% for single outflow composite grafts, and 52% for dual outflow composite grafts. Limb salvage rates for femoropopliteal procedures were 73% for composite grafts, 63% for polytetrafluoroethylene, and 82% for vein grafts, and for femorotibial procedures were 53% for single outflow composite grafts, 65% for dual outflow composite grafts, and 86% for vein grafts. CONCLUSIONS: Composite grafts achieve long-term preservation of ischemic limbs in patients who are facing limb loss because of poor run-off and have insufficient autogenous vein for a graft.

Aged↗
PubMed1988

Computed tomography of abdominal aortic aneurysm. An in vivo pathological report with a note on dynamic predictors.

A group of computed tomography (CT) descriptors were derived for abdominal aortic aneurysms. Terminology was defined and applied to the interpretation of the CT image in 55 prospective cases. Correlation of geometric parameters of aneurysm and analysis of the relationship of internal aneurysm components such as lumen and thrombus was performed. Predictive growth patterns for aneurysm demonstrated a synchronous increase in the volume of thrombus within the aneurysm in those aneurysms measuring 5 to 7 cm. Aneurysms greater than 7 cm were associated with an expansion of the patent pulsatile lumen, with no appreciable increase in thrombus volume. The thrombus-lumen ratio effectively described the changing internal architecture of aneurysm associated with increase in size. Proper utilization of CT descriptors develops a language that interprets aneurysm stability and potential for rupture and may provide an improved basis for timely surgical planning.

Aged↗
PubMed1988

Elastin metabolism of the infrarenal aorta.

Aortic tissue elastase and alpha 1-antitrypsin were assayed in 67 patients with different types of infrarenal aortic disease; occlusive disease, elective abdominal aortic aneurysms (AAAs), multiple aneurysms, and ruptured aneurysms. Elastase modified by alpha 1-antitrypsin (elastase/alpha 1-antitrypsin) increased significantly as the type of aortic disease changed from occlusive to aneurysmal disease. Aortic elastase was significantly higher in patients with AAAs, multiple aneurysms, and ruptured AAAs compared with occlusive disease. The alpha 1-antitrypsin, was significantly lower in patients with multiple aneurysms and ruptured AAAs. These data suggest that the ratio between elastase and its major serum inhibitor, alpha 1-antitrypsin, is significantly altered in the aortic wall in different types of infrarenal aortic disease. In addition, the ratio between these two enzyme systems changes in favor of more proteolytic activity as the type of infrarenal disease changes from occlusive to aneurysmal.

Aorta, Abdominal↗