Biomedical subjects

C C Wu

Publications and source records attributed to C C Wu.

At least 55 records · Page 3Linked to original sources

PubMed2001

Pulsatility of ascending aorta and restenosis after coronary angioplasty in patients >60 years of age with stable angina pectoris.

A recent study has demonstrated that the pulsatility of the ascending aorta is a strong predictive factor for restenosis after coronary angioplasty. However, whether the pulsatility of the ascending aorta is still a significant predictor for restenosis in elderly patients with a stiffer aorta is unknown. We investigated the relation between arterial pulsatility in the ascending aorta and restenosis after coronary angioplasty in patients aged > 60 years. Eighty-seven consecutive patients (80 men, aged 72.5 +/- 5.1 years) with stable angina were included. Before angioplasty, the arterial systolic, diastolic, and mean pressure waveforms of the ascending aorta were measured. We used fractional pulse pressure (PPf, the ratio of pulse pressure to mean pressure) and pulsatility index (PI, the ratio of pulse pressure to diastolic pressure) to estimate the pulsatility of the ascending aorta. Angiographic restenosis occurred in 39 patients. Pulse pressure, PPf, and PI were significantly higher in patients with restenosis after coronary angioplasty (restenosis vs without restenosis: pulse pressure, 77.6 +/- 12.2 vs 66.1 +/- 15.4 mm Hg [p < 0.001]; PPf, 0.80 +/- 0.09 vs 0.69 +/- 0.11 [p < 0.001]; PI, 1.19 +/- 0.20 vs 0.98 +/- 0.21 [p < 0.001]). After multivariate stepwise adjustment of risk factors of restenosis and using receiver-operating characteristic analysis, the odds ratio (OR) of restenosis was: pulse pressure > 66 mm Hg, OR 5.88 (95% confidence interval [CI] 2.17 to 15.93); PPf > 0.72, OR 13.71 (95% CI 4.81 to 39.05); PI > 1.06, OR 13.56 (95% CI 4.67 to 39.38). Moreover, among patients aged > 70 years (n = 60), the predictive values of PPf and PI were even higher than those in patients aged < or = 70 years (n = 27). Thus, in elderly patients with stable angina, the pulsatility of the ascending aorta is a powerful predictor of restenosis after coronary angioplasty.

Aged↗

PubMed2001

Synthesis of 1-benzyl-3-(5'-hydroxymethyl-2'-furyl)indazole analogues as novel antiplatelet agents.

1-Benzyl-3-(5'-hydroxymethyl-2'-furyl)indazole (28, YC-1) was selected as the lead compound for systemic structural modification. After screening for antiplatelet activity, SARs of YC-1 analogues were established. Among these potent active derivatives, compounds 29, 30, 31, 44, and 45 functioned as potent activators of sGC and inhibitors of PDE5 with potency comparable to that of YC-1. In addition, compound 58 was found to be a selective and potent inhibitor of protease-activated receptor type 4 (PAR4)-dependent platelet activation.

3',5'-Cyclic-GMP Phosphodiesterases↗

PubMed2001

Effect of diallyl sulfide and diallyl disulfide, the active principles of garlic, on the aflatoxin B(1)-induced DNA damage in primary rat hepatocytes.

The objective of this study was to investigate the effect of the active principles in garlic-- diallyl sulfide (DAS) and diallyl disulfide (DADS)--on aflatoxin B(1) (AFB(1))-induced DNA damage in primary rat hepatocytes. Primary rat hepatocytes, induced with DNA damage using 10 microM AFB(1) were used as an experimental model. According to the results of LDH leakage, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS significantly increased the viability of hepatocytes compared with the AFB(1) controls after 4, 8 and 24 h treatment (P<0.05). According to the results of unscheduled DNA synthesis (UDS) test, 0.5 and 2 mM of DAS or 0.5 and 1 mM of DADS could significantly decrease the DNA damage induced by AFB(1) (P<0.05). Furthermore, 0.5 and 2 mM DAS or 0.5 and 1 mM DADS could increase the glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities as compared with the AFB(1) controls after 24 h treatment (P<0.05). Results of immunoblot analysis of cytosolic GST isoenzyme indicate that the levels of GST isoform Ya, Yb2 and Yc were markedly increased after treatment with 0.5 and 2 mM DAS or 0.5 and 1 mM DADS compared with the AFB(1) control. These results indicate that 0.5 and 2 mM DAS or 0.5 and 1 mM DADS might protect hepatocytes from AFB(1)-induced DNA damage via increasing the activities of GST and GPx.

Aflatoxin B1↗

PubMed2001

Major histocompatibility complex class II polymorphisms in Macaca mulatta: factors influencing comprehensive genotyping of Macaca mulatta (Mamu)-DQA1 alleles by PCR-RFLP in archival samples.

In the last 5 years, HLA class II genotyping methods have been adapted for genotyping of class II loci in rhesus macaques. Since previously published typing protocols were used on samples that were collected and stored under ideal conditions, it was of interest to determine if these methods were adequate for genotyping a large collection of archival samples from which DNA had been isolated and stored under various conditions. Established macaque DQA1 typing protocols were modified to optimize the typing procedure and enhance the ability to successfully genotype DNA from samples that were of poor quality and/or quantity. Long-term storage of whole-blood buffy coats or stored DNA extracted from whole-blood buffy coats did not affect typing success; however, amplification and typing of DNA extracted from archival samples of plasma were difficult and resulted in a low success rate. This suggests that amplification and DQA1-genotyping of archival samples is possible with a modified protocol, but is influenced by the age and source of the sample, and to a lesser extent, the method used to extract DNA from sample substrates.

Animals↗

PubMed2001

In vivo magnetic resonance (MR) study of fatty liver: importance of intracellular ultrastructural alteration for MR tissue parameters change.

Fatty liver is thought to have a shorter T1 relaxation time than normal liver tissue, due to the accumulation of triglyceride. Previous studies regarding T1 and T2 relaxation times, however, show widely different results. In order to elucidate the mechanism responsible for the changes and diversity of relaxation times in fatty liver, we created two animal models in 14 rabbits, one acute form (N = 6) and the other chronic form (N = 8). Four rabbits were taken as a control group. Tissue relaxation times and the magnetization transfer (MT) effect of the liver tissue in these two models were measured. The results were correlated with biochemical analysis of water and fat content and histological examination, including findings in light microscopy and electron microscopy. Although the fatty ratio in both forms of fatty liver was similar, their tissue relaxation rate and MT effect were significantly different. The acute form showed prolongation of both T1 and T2 relaxation times (512 +/- 51 msec vs. 710 +/- 95 msec and 39 +/- 1.8 msec vs. 48 +/- 3.7 msec, respectively) and a decrease of the MT effect (50 +/- 5.1% vs. 38 +/- 6.3%), compared to those of the control group and preinduction liver. The chronic form showed shorter T1 and T2 values (526 +/- 36 msec vs. 406 +/- 56 msec and 36 +/- 1.6 msec vs. 33 +/- 2.3 msec, respectively) and a stronger MT effect (21 +/- 0.9% vs. 26 +/- 2.3%). In acute form fatty liver, electron microscopic examination revealed dramatic subcellular changes, such as vesicular transformation, a markedly increased amount of smooth endoplasmic reticulum (SER), and disruption of the crista. These changes were not found in the chronic form fatty liver. From this study, we concluded that the ultrastructural alteration in the subcellular organelles of hepatocyte might play a crucial role for the chameleonic presentation of MR tissue parameters in fatty liver.

Animals↗

PubMed2001

Liver resection for hepatocellular carcinoma in patients with end-stage renal failure.

BACKGROUND AND OBJECTIVES: Surgical resection remains the main option for curing hepatocellular carcinoma (HCC). However, liver resection in patients with end-stage renal disease (ESRD) is risky. The aim of this study is to clarify the role of liver resection for treating HCC in patients with ESRD. METHODS: A retrospective review was carried out on 468 patients who underwent liver resection for HCC between 1989 and 1999. The clinicopathological characteristics and operative results of 12 patients who had ESRD (ESRD group) were compared with those of the other 456 patients who did not have ESRD (non-ESRD group). In the ESRD group, heparin-free hemodialysis using the periodic saline-rinse method was performed during the perioperative period. RESULTS: The ESRD group had lower hemoglobin and a higher serum creatinine levels. Other patient background and tumor pathological characteristics were comparable between the two groups as well. The operative morbidity and mortality between the two groups were also similar. The 5-year disease-free survival rates for ESRD and non-ESRD groups were 35.0 and 34.2% (P = 0.31), respectively, while the 5-year actuarial survival rates were 67.8 and 53.3% (P = 0.54), respectively. CONCLUSION: With improving techniques and knowledge of dialysis, liver resection for HCC is justified in selected patients with ESRD.

Adult↗

PubMed2001

Ubiquitin-activating enzyme (E1) isoforms in lens epithelial cells: origin of translation, E2 specificity and cellular localization determined with novel site-specific antibodies.

Lens development and response to peroxide stress are associated with dramatic changes in protein ubiquitination, reflecting dynamic changes in activity of the ubiquitin-activating enzyme (E1). Two isoforms of E1 (E1A and E1B) have been identified in lens cells although only one E1 mRNA, containing three potential translational start sites, has been detected. Novel, site-specific antibodies to E1 were generated and the hypothesis that the two isoforms of E1 are translated from alternative initiation codons of a single mRNA was tested. Antibodies raised against E1A-N peptide (Met(1)to Cys(23)of E1A) reacted only with E1A by immunoblot and immunoprecipitation. Antibodies raised against E1B-N peptide (Met(1)to Glu(25)of E1B or Met(41)to Glu(65)of E1A) and E1AB-C peptide (His(1030)to Arg(1058)of E1A or His(990)to Arg(1018)of E1B) reacted with both E1A and E1B. These results indicate that (1) E1A and E1B contain the same C-terminal residues; (2) E1A contains the N terminal sequence of E1B; and (3) E1B does not contain the N terminal sequence of E1A. The two isoforms of lens E1 are therefore translated from a single mRNA. Specifically, E1A is translated from the first initiation codon, and E1B translated from the second initiation codon. E1A and E1B were affinity-purified, and their ability to 'charge' ubiquitin carrier proteins (E2s) with activated ubiquitin was compared in a cell-free system. E1A and E1B were indistinguishable with respect to charging different E2s. However, E1 immunolocalization studies with human lens epithelial cells indicate that E1A and E1B are preferentially localized to the nucleus and cytosol, respectively. This observation suggests that E1A and E1B ubiquitinate different proteins and serve different functions in intact cells.

Animals↗

PubMed2001

Patellar tension band wiring: a revised technique.

Using a modified AO tension band wiring technique to treat a patellar fracture has become popular and has achieved a high success rate. However, the technique of Kirschner wire insertion has not been considered in detail, which may migrate and consequently introduce fragments loss of reduction. A revised technique involving bending both ends of the Kirschner wires was prospectively studied. Sixty-eight consecutive patients were so treated, and 62 patients were followed-up for at least 2 years (range 2-6 years). All fractures healed with a union rate of 100% (62/62) and a union period of 2.5 +/- 0.5 months. Skin irritation was noted in 2 patients (3%). All patients achieved a satisfactory result. We therefore recommend this revised technique to treat all patellar fractures because of its high union rate and low complication rate.

Adolescent↗

PubMed2001

An improved surgical technique to treat femoral shaft malunion: revised reamed intramedullary nailing technique.

Twenty-four consecutive adult patients who sustained a femoral shaft angular or rotational deformity, with or without significant shortening, were treated with skeletal traction of the femoral condyle, transverse femoral osteotomy, realignment of the shaft axis with or without lengthening, stable reamed intramedullary nail stabilization, and corticocancellous bone grafting. Twenty-one patients who underwent the treatment were followed-up for at least 1 year (range 1.0-4.5 years), and all achieved a solid union. The union rate was 100% (21/21) with a union period of 4.9+/-0.5 months. There were no significant complications. All patients achieved a satisfactory outcome as indicated by patient satisfaction and physician assessment of outcome (p < 0.001, Fisher's exact test). In the present series, the use of this revised reamed nailing technique resulted in a high success rate and a low complication rate. It provides an effective alternative treatment in indicated cases.

Adolescent↗

PubMed2001

Management of acute pancreatitis: results of a 15-year experience in Taiwan.

In the past two decades, there have been great changes regarding the policy for treating acute pancreatitis. The aim of this study was to examine the chronological changes in the management of acute pancreatitis in a tertiary referral center. A retrospective review was carried out of the management approaches for acute pancreatitis in the 15 years since 1984. The patients were divided into groups according to the admission date, representing two periods: period 1, from 1984 through 1992; and period 2, from 1993 through 1999. Decision-making for treating acute pancreatitis was based mainly on Beger's criteria. The background features and treatment outcome were compared between the two periods. The severity of pancreatitis was based on the Atlanta classification system. Octreotide was available from January 1993. No differences could be found between the two periods regarding the patients' background characteristics or severity of pancreatitis. Patients in period 2 had a longer interval between the onset of pancreatitis and surgery, and a lower incidence of pancreatectomy. Although the surgical morbidity, mortality, and reoperation rates were not significantly different between the two periods, more patients with severe acute pancreatitis in period 2 received nonsurgical treatment, and a lower mortality rate was also noted. With improvements in critical care, increasing experience, and better surgical techniques, even patients with severe acute pancreatitis can be treated by nonsurgical means. However, aggressive surgical intervention is necessary for patients who have signs of infected necrosis and whose disease is not controllable by conservative methods.

Adult↗

PubMed2001

Bilateral neurotrophic keratopathy complicating Vidian neurectomy.

PURPOSE: To present a case of bilateral neurotrophic keratopathy with miosis after bilateral Vidian neurectomy for vasomotor rhinitis. METHODS: Observational case report. RESULTS: A 68 year-old man presented with irritation and blurred vision in both eyes 2 weeks after bilateral Vidian neurectomy. Slit-lamp examination revealed a large epithelial defect, typical of neurotrophic keratopathy, in the inferior two-thirds of cornea in both eyes. Corneal sensitivity test with a Cochet-Bonnet anesthesiometer and electrical study of the blink reflex indicated bilateral trigeminal dysfunction. Both pupils were miotic, and tests with hydroxyamphetamine 1% and epinephrine 0.1% showed postganglionic sympathetic nerve damage. The corneal epithelial defects healed after 2 months of treatment with systemic prednisolone, vitamin B(12) and tarsorrhaphy. CONCLUSION: Neurotrophic keratopathy associated with dry eye syndrome may be a serious complication of Vidian neurectomy.

Aged↗

PubMed2001

Effects of organosulfur compounds from garlic oil on the antioxidation system in rat liver and red blood cells.

The modulation of garlic oil (GO) and three allyl compounds, diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS), on the antioxidation system in rat livers and red blood cells was examined. Rats were orally administered GO (200 mg/kg body weight), DAS (20, 80 mg/kg body weight), DADS (80 mg/kg body weight) or DATS (70 mg/kg body weight) three times a week for 6 weeks. Control rats received corn oil (2 ml/kg body weight) alone. GO, DADS and DATS treatment significantly increased the glutathione (GSH) content (48-84%) in red blood cells (P < 0.05). DATS displayed a greater enhancement than GO and DADS (P < 0.05). Hemolysis induced by tert-butyl hydroperoxide was not suppressed by GO or allyl compound treatment although higher GSH content was evident. Hepatic GSH was not influenced by garlic components. In rat livers, DADS and DATS significantly increased the activity of GSH reductase (46 and 54%, respectively) and of GSH S-transferase (GST) (63 and 103%, respectively), but decreased the GSH peroxidase activity (27 and 28%, respectively). In contrast, GSH reductase and GST activities in the DAS group, either 20 or 80 mg/kg body weight, were similar to the control group. A decrease of GSH peroxidase activity was observed in rats dosed with 80 mg/kg body weight (P < 0.05). An increase in GST activity and a decrease in GSH peroxidase activities were also noted in GO-treated rats (P < 0.05). In red blood cells, three GSH-related antioxidant enzyme activities were not affected by garlic oil and its organosulfur components. Immunoblot assay showed that, accompanying the increase in hepatic GST activity, GO, DADS, DAS (80 mg/kg body weight) and DATS increased the expression of GST Ya, Yb1 and Yc proteins. Results indicate that GO and three allyl compounds play a differential role in modulation of the GSH-related antioxidant system in rat livers and red blood cells.

Allyl Compounds↗

PubMed2001

Accuracy of biphasic response, sustained improvement and worsening during dobutamine echocardiography in predicting recovery of resting myocardial dysfunction after revascularization: comparison with thallium-201 SPECT.

To evaluate the accuracy of various types of wall motion response during dobutamine echocardiography (DE) in predicting functional recovery after revascularization, we studied 30 patients with stable coronary disease and left ventricular dysfunction by simultaneous DE and (201)Tl reinjection SPECT. Among 480 segments (16 segments/patient), 199 had abnormal wall motion at baseline and 167 were revascularized. The predictive value for recovery of function was 72% for a biphasic response, 61% for sustained improvement, 77% for worsening, and 27% for no change (p < 0.01 vs. each). Biphasic response had a sensitivity of 40% and specificity of 85%. Combining biphasic, sustained improvement and worsening responses, the sensitivity, specificity and accuracy were 76%, 65% and 71%, respectively. For (201)Tl SPECT, they were 90%, 65% and 78%, respectively. Thus, a biphasic response alone is of low sensitivity. Combination of biphasic, sustained improvement and worsening responses gives an accuracy rate comparable to that of (201)Tl reinjection SPECT in assessing functional recovery.

Adult↗

PubMed2001

Alterations of myocardial ultrasonic tissue characterization by coronary angioplasty in patients with chronic stable coronary artery disease.

We conducted a study to delineate the alterations in the cyclic changes of myocardial ultrasonic integrated backscatter (IBS) in patients receiving angioplasty for chronic coronary artery disease. Ultrasonic tissue characterization (UTC) and dobutamine stress echocardiography were performed in 43 patients before and 24 h after angioplasty, as well as before the follow-up angiography 3 months later. For segments being normokinetic with ischemic burden, the blunted amplitude and increased nadir deviation of IBS cyclic modulation recovered soon after angioplasty. For dyssynergic segments with contractile reserve, the angioplasty rebuilt the amplitude before the wall motion recovered, but corrected the nadir deviation tardily. In both circumstances, the coronary restenosis abolished the initial restoration. Those nonviable segments persistently revealed large deviations and small weighted amplitudes irrelevant to coronary lesions. The progress of myocardial ischemia, the development of wall motion dyssynergy and, then, the loss of viability, show different patterns of alterations in UTC after alleviating coronary obstructions.

Aged↗

PubMed2001

Molecular identification and characterization of turkey IFN-gamma gene.

The cDNAs of turkey and chicken interferon gamma (IFN-gamma) were cloned and the functional activity of turkey and chicken IFN-gamma was compared. The coding region of turkey IFN-gamma gene encodes a predicted mature protein of 145 amino acids with a molecular weight at 16.8 kDa. Compared with type I IFN, the IFN-gamma between turkey and chicken also had the same size and high degree of identity at the nucleotide (96.0%) and amino acid (96.4%) sequence. Turkey IFN-gamma was cross-reactive with chicken cells. Both turkey and chicken IFN-gamma could induce production of nitric oxide by turkey or chicken macrophages. Turkey IFN-gamma also had similar degree of sensitivity to heat and pH 2.0 as chicken IFN-gamma. The functional activity of both turkey and chicken IFN-gamma could be neutralized by a monoclonal antibody specific to chicken IFN-gamma to a similar extent. These results indicated that IFN-gamma protein was cross-reactive between turkey and chicken.

Animals↗

PubMed2001

Melatonin prevents endotoxin-induced circulatory failure in rats.

The pineal secretory product melatonin was found to exert protective effects in septic shock. In a host infected by bacterial lipopolysaccharide (LPS), the expression and release of proinflammatory tumor necrosis factor-alpha (TNF-alpha) is rapidly increased, suggesting that TNF-alpha is associated with the etiology of endotoxic shock. Recent reports show that the expression of NO synthase (NOS) II and the production of superoxide anion (O2*-) also contribute to the pathophysiology of septic shock. In the present study we demonstrate that melatonin prevents circulatory failure in rats with endotoxemia and improves survival in mice treated with a lethal dose of LPS. The beneficial hemodynamic effects of melatonin in the endotoxemic animal appear to be associated with the inhibition of (i) the release of TNF-alpha in plasma, (ii) the expression of NOS II in liver, and (iii) the production of O2*- in aortae. In addition, the infiltration of polymorphonuclear neutrophils into the liver from the surviving LPS mice treated with melatonin was reduced. Thus, our results support the clinical use of melatonin in endotoxemia.

Animals↗

PubMed2001

Improving operative safety for cirrhotic liver resection.

BACKGROUND: Liver resection in a patient with cirrhosis carries increased risk. The purposes of this study were to review the results of cirrhotic liver resection in the past decade and to propose safe strategies for cirrhotic liver resection. METHODS: Based on the date of operation, 359 cirrhotic liver resections in 329 patients were divided into two intervals: period 1, from September 1989 to December 1994, and period 2, from January 1995 to December 1999. The patient backgrounds, operative procedures and early postoperative results were compared between the two periods. The factors that influenced surgical morbidity were analysed. RESULTS: In period 2, patient age was higher and the amounts of blood loss and blood transfused were lower. Although postoperative morbidity rates were similar, blood transfusion requirement, postoperative hospital stay and mortality rate were significantly reduced in period 2. No death occurred in 154 consecutive cirrhotic liver resections in the last 38 months of the study. Prothrombin activity and operative time were independent factors that influenced postoperative morbidity. CONCLUSION: With improving perioperative assessment and operative techniques, most complications after cirrhotic liver resection can be treated with a low mortality rate. However, more care should be taken if prothrombin activity is low or there is a long operating time.

Adult↗

PubMed2001

Derangement of heart rate variability during a catastrophic earthquake: a possible mechanism for increased heart attacks.

At 1:47 AM on September 21, 1999, the middle part of Taiwan was struck by a major earthquake measuring 7.3 on the Richter scale. It has been shown that the mental stress caused by an earthquake could lead to a short- or long-term increase in frequency of cardiac death probably through activation of the sympathetic nervous system. The aim of this study was to investigate the effects of emotional stress on the autonomic system during an actual earthquake. Fifteen patients receiving a 24-hour Holter ECG study starting from 10+/-4 hours before the onset of the earthquake were included for the analysis of time- and frequency-domains of heart rate variability (HRV) at several time periods. A 24-hour Holter study recorded 2-6 months before the earthquake in 30 age- and sex-matched subjects served as the control group. Heart rate and the low frequency (LF) to high frequency (HF) ratio increased significantly after the earthquake and were attributed mainly to the withdrawal of the high frequency component (parasympathetic activity) of HRV. Sympathetic activation was blunted in elderly subjects > 60 years old. The concomitant ST-T depression observed in the Holter study correlated with a higher increment of LF as compared to HF components. The changes observed in HRV recovered completely 40 minutes following the earthquake. The derangement of HRV results from the withdrawal of the parasympathetic component and the arousal of sympathetic activity by the stressful earthquake. However, this autonomic derangement returned towards normal 40 minutes following the earthquake.

Adult↗