Biomedical subjects

C C Wu

Publications and source records attributed to C C Wu.

At least 109 records · Page 6Linked to original sources

PubMed2000

Proteomics of rat liver Golgi complex: minor proteins are identified through sequential fractionation.

The discovery of novel proteins resident to the Golgi complex will fuel our future studies of Golgi structure/function and provide justification for proteomic analysis of this organelle. Our approach to Golgi proteomics was to first isolate and characterize the intact organelle free of proteins in transit by use of tissue pretreated with cycloheximide. Then the stacked Golgi fraction was fractionated into biochemically defined subfractions: Triton X-114 insoluble, aqueous, and detergent phases. The aqueous and detergent phases were further fractionated by anion-exchange column chromatography. In addition, radiolabeled cytosol was incubated with stacked Golgi fractions containing proteins in transit, and the proteins bound to the Golgi stacks in an energy-dependent manner were characterized. All fractions were analyzed by two-dimensional (2-D) gel electrophoresis and identification numbers were given to 588 unique 2-D spots. Tandem mass spectrometry was used to analyze 93 of the most abundant 2-D spots taken from preparative Triton X-114 insoluble, aqueous and detergent phase 2-D gels. Fifty-one known and 22 unknown proteins were identified. This study represents the first installment in the mammalian Golgi proteome database. Our data suggest that cell fractionation followed by biochemical dissection of specific classes of molecules provides a significant advantage for the identification of low abundance proteins in organelles.

Animals↗

PubMed2000

Proteomics reveal a link between the endoplasmic reticulum and lipid secretory mechanisms in mammary epithelial cells.

The synthesis and secretion of lipids by mammary epithelial cells is a highly ordered process that involves several distinct steps. Triacylglycerols are synthesized in the endoplasmic reticulum and incorporated into microlipid droplets which coalesce into cytoplasmic lipid droplets. These are vectorially transported to the apical plasma membrane where they are secreted into the milk surrounded by a membrane bilayer. The origin of this membrane as well as the mechanism by which cytoplasmic lipid droplets form and become surrounded by membrane is poorly understood. Proteomic analysis of the protein composition of milk fat globules and cytoplasmic lipid droplet has revealed that the endoplasmic reticulum is not only involved in the synthesis of the lipid but also potentially contributes to the membrane component of milk fat globules. The proteins identified suggest possible mechanisms of multiple steps during this process. Completion of the proteome of milk fat globule membranes and cytoplasmic lipid droplets will provide the necessary reporter molecules to follow and dissect the mechanisms of the sorting and ultimate secretion of cytoplasmic lipid droplets.

Animals↗

PubMed2000

Benzalkonium chloride and gentamicin cause a leak in corneal epithelial cell membrane.

The purposes of this study are to characterize the pathophysiological effects of benzalkonium chloride and gentamicin on corneal epithelial cells and to determine the concentration dependent effect of these agents on membrane currents of these cells. Rabbit corneal epithelial cells were isolated and subdivided into small, medium and large cells according to their cell capacitance. Using whole cell clamp technique, potassium current of corneal epithelial cells was recorded. Transmembrane current was measured again after bathing in benzalkonium chloride 1, 3, 10, 30 and 100 micrometer ml(-1)for 3 min. The effect of gentamicin was tested at concentrations of 0.4, 1.0, 2.0, 4.0 and 10 mg ml(-1). Synergistic effect of gentamicin of the above mentioned concentrations in the presence of benzalkonium chloride 1 microgram ml(-1)was also measured. We found that small corneal epithelial cells had the highest depolarization-gated, outward potassium current density and large cells had the lowest current density, while medium cells had a current density in between. Benzalkonium chloride induced a concentration dependent increase in the leak current with increasing concentration from 1 to 100 microgram ml(-1). The increase of leak current in medium and large cells was less than that in the small cells. Gentamicin also caused a concentration dependent increase in leak current density from 0.4 to 10.0 mg ml(-1). The increase in leak current density was statistically significant when the concentration was 2.0 mg ml(-1)or higher in small corneal epithelial cells and 1.0 mg ml(-1)or higher in the medium and large cells. Benzalkonium chloride 1.0 microgram ml(-1)augmented the effect of gentamicin on epithelial cell membrane. The extent of enhancement was more prominent in larger than smaller cells. Using whole-cell clamp technique, we were able to determine the threshold concentration of gentamicin and benzalkonium chloride on the integrity of corneal epithelial cell membrane. The toxic action of both agents is mediated by an increase in leak current. We propose that the whole-cell clamp technique is a sensitive and useful tool in determining cytotoxic effects of various agents.

Animals↗

PubMed2000

Premedication with dextromethorphan provides posthemorrhoidectomy pain relief.

PURPOSE: Previous studies have shown that N-methyl-D-aspartate receptor antagonists provide a preemptive analgesic effect in humans. This study was designed to examine whether premedication with dextromethorphan, an N-methyl-D-aspartate antagonist, also provided a preemptive analgesic effect that improved postoperative pain management. METHODS: Sixty patients who were American Society of Anesthesiologists status I and II scheduled for hemorrhoidectomy (modified Whitehead procedure) were included in the study. Patients were randomly assigned to the control and study groups. For the control group patients received chlorpheniramine maleate (20 mg), a component of the injection form of dextromethorphan, intramuscular injection 30 minutes before skin incision. In the study group dextromethorphan 40 mg containing 20 mg chlorpheniramine maleate (intramuscular) was given as premedication 30 minutes before skin incision. Pethidine (1 mg/kg, intramuscular) was given for pain relief as required postoperatively. The time to first pethidine injection, total pethidine consumption, worst pain score, and pethidine-related side effects were recorded for 48 hours postoperatively. RESULTS: The times to first pethidine injection (mean +/- standard error of the mean) were 5.2 +/- 3 and 19.6 +/- 6 hours in the control and study groups, respectively. Total pethidine consumption was 140 +/- 11.3 and 63.5 +/- 11.8 mg in the control and study groups. The worst visual analog scale pain scores were 7.4 +/- 0.2 and 5.6 +/- 0.3 in the control and study groups during the two-day observation. The numbers of patients who required pethidine injection were 29 and 20 in the control and study groups, respectively. Two patients suffered pethidine-related side effects, such as nausea, vomiting, dizziness, and headache, in the control group, and no patient complained of any side effect in the study group. CONCLUSION: We found that dextromethorphan premedication provided a preemptive analgesic effect, thus producing reduced postoperative pain and pethidine requirement and improved recovery from hemorrhoidectomy.

Adult↗

PubMed2000

Tibial shaft malunion treated with reamed intramedullary nailing: a revised technique.

Thirty-seven consecutive adult tibial shaft malunions which had not undergone surgical treatment were prospectively treated with reamed intramedullary nailing. Indications for this treatment modality included a malunion of a tibial shaft which had only been conservatively treated, lesion level fitting for traditional or locked reamed intramedullary nail fixation, less than 2 cm shortening, and without evidence of deep infection at present. The malunions were treated with fibulotomy, closed wedge tibial osteotomy, open reaming of the marrow cavity, stable reamed intramedullary nail stabilization with or without supplementation, and cancellous bone grafting. Thirty-four (92%) patients were followed up for at least 1 year (range 1.0-4.3 years), and all achieved a solid union. The union period was 5.8+/-0.8 months. Complications included 2 (6%) patients with deep infection and 1 (3%) with cortical perforation. However, all 3 patients recovered completely after adequate management. In conclusion, a reamed intramedullary nail is an ideal instrument for tibial shaft malunions in indicated cases. Good exposure of the bony segments to ream the marrow cavity precisely can avoid cortical perforation. Gentle dissection of the soft tissues may lower the infection rate. Concomitant cancellous bone grafting can improve the union rate.

Adolescent↗

PubMed2000

Epstein-Barr virus-associated gastric carcinomas: relation to H. pylori infection and genetic alterations.

BACKGROUND & AIMS: The association of Epstein-Barr virus (EBV) and gastric carcinomas (GCs) has been shown to vary among different populations and certain histological subtypes. Few studies have addressed the status of Helicobacter pylori infection and genetic alterations in these EBV-positive or -negative GCs. METHODS: Eleven gastric lymphoepithelioma-like carcinomas (LELCs) and 139 cases of common non-LELCs were evaluated for the presence of EBV DNA using polymerase chain reaction (PCR) and RNA in situ hybridization. H. pylori infection was determined by anti-H. pylori immunoglobulin G in preoperative sera. Immunostaining for p53, c-erbB-2, and E-cadherin was performed. Microsatellite instability was analyzed by PCR using 10 primers. RESULTS: EBV was detected in 11 (100%) LELCs and in 19 (13.7%) of 139 common GCs. Compared with EBV-negative GCs, gastric LELCs tended to have a relatively higher frequency of proximal location, diffuse histological subtype, p53 overexpression, and reduced E-cadherin expression but a lower frequency of lymph node metastasis, previous H. pylori infection, and c-erbB-2 overexpression. In contrast, no significant difference of clinicopathologic and genetic profiles was observed between EBV-positive non-LELC GCs and EBV-negative GCs. No correlation of microsatellite instability was found among these 3 subsets of GCs. CONCLUSIONS: Dissecting clinicopathologic characteristics and infection status of EBV and H. pylori provide additional evidence of etiological and genetic heterogeneity for GC. Distinct clinicopathologic and genetic pathways exist in gastric LELCs, in which EBV may play a more important role than H. pylori infection.

Adenocarcinoma↗

PubMed2000

Selective sentinel lymph node dissection in breast cancer: experiences from Taiwan.

The significance of the sentinel lymph node (SLN) was examined in 58 Chinese breast cancer patients. The method of technetium-99m sulfur colloid injection and the intraoperative gamma probe was found to be very useful for identifying the SLN. The positive predictive value was 64.5%, and the negative predictive value was 93.2%. Findings suggest that lymph node dissection is not necessary in breast cancer patients with a negative SLN.

Adult↗

PubMed2000

Ultrasonic tissue characterization with integrated backscatter during inotropic stimulation.

Ultrasonic tissue characterization with integrated backscatter is an objective method to quantitatively define the physical state of the myocardium. To determine if backscatter imaging during inotropic stimulation could be used objectively to determine the myocardial viability and ischemia in patients with ischemic heart disease, the backscatter changes were examined in 23 patients with myocardial infarction during dobutamine stress two-dimensional (2-D) echocardiography. Coronary angiography was performed within 1 to 2 days after the stress test. The results of this study demonstrated that changes in backscatter variability correlated significantly with the wall motion changes in stress echocardiography during dobutamine infusion (p < 0.0001). In addition, it was shown that the backscatter changes were significantly different in various types of myocardial tissue. In 23 healthy control segments, the ultrasonic backscatter variability was preserved and unchanged during inotropic stimulation (p = NS). In 15 viable infarct zones, restoration or an increase in backscatter variability during low-dose dobutamine infusion was noted, this being lost when ischemia developing during high-dose dobutamine infusion (p < 0.01). In 9 nonviable infarct zones, the phase-weighted variation was usually < or = 0 and did not change significantly during inotropic stimulation, regardless of the patency of the infarct-related arteries. In 15 remote ischemic myocardial zones, the backscatter variability was preserved at the baseline level, did not change during low-dose dobutamine infusion, but decreased significantly during high-dose dobutamine stress (p < 0.01). In conclusion, dobutamine stress tissue characterization could offer an objective approach for the detection of myocardial viability and ischemia, and might be a useful adjunct to the conventional stress echocardiography.

Cardiotonic Agents↗

PubMed2000

Power Doppler-derived speckle tracking image of intraventricular flow in patients with anterior myocardial infarction: correlation with left ventricular thrombosis.

The abnormal spatial distribution of intraventricular flow is superior to clinical and two-dimensional (2-D) echocardiographic variables in predicting left ventricular thrombosis after myocardial infarction. Echocardiography was prospectively performed in 79 patients within 72 h after anterior wall myocardial infarction onset and repeated before discharge. The apical rotating flow pattern in color flow map was recognized as abnormal. By power Doppler echocardiography, the moving blood could generate speckle tracking images to delineate the intraventricular flow. A swirling flow pattern indicating the compartmentalization of left ventricular blood flow with some blood stagnant in the apical dyssynergic area was identified. The flow pattern shown by the speckle tracking image was superior to the color-flow map in correlating with left ventricular thrombosis. It implicated that the more the detail in which we can describe the blood flow pathway, the more information we can realize.

Adult↗

PubMed2000

Esophageal varices in congenital heart disease with total anomalous pulmonary venous connection.

Total anomalous pulmonary venous connection (TAPVC) is an uncommon congenital anomaly in which the anatomical presentations vary widely among patients. We hereby present two newborns with TAPVC associated with asplenia syndrome; both had severe esophageal varices due to infradiaphragmatic pulmonary venous drainage. Ultrafast computed tomography (CT) scanning was superior to color Doppler echocardiography and cardiac catheterization as it provided a detailed portrait of the pulmonary drainage. The remarkable radiographic manifestations are presented.

Cardiac Catheterization↗

PubMed2000

Proteomic analysis of two functional states of the Golgi complex in mammary epithelial cells.

Organellar compartments involved in secretion are expanded during the transition from late pregnancy (basal secretory state) to lactation (maximal secretory state) to accommodate for the increased secretory function required for copious milk production in mammary epithelial cells. The Golgi complex is a major organelle of the secretory pathway and functions to sort, package, distribute, and post-translationally modify newly synthesized proteins and membrane lipids. These complex functions of the Golgi are reflected in the protein complement of the organelle. Therefore, using proteomics, the protein complements of Golgi fractions isolated at two functional states (basal and maximal) were compared to identify some of the molecular changes that occur during this transition. This global analysis has revealed that only a subset of the total proteins is upregulated from steady state during the transition. Identification of these proteins by tandem mass spectrometry has revealed several classes of proteins involved in the regulation of membrane fusion and secretion. This first installment of the functional proteomic analysis of the Golgi complex begins to define the molecular basis for the transition from basal to maximal secretion.

Animals↗

PubMed2000

YD-3, a novel inhibitor of protease-induced platelet activation.

1. In the present study, the antiplatelet effects and mechanisms of a new synthetic compound YD-3 [1-benzyl-3(ethoxycarbonylphenyl)-indazole] were examined. 2. YD-3 inhibited the aggregation of washed rabbit platelets caused by thrombin (IC(50)=28.3 microM), but had no or little inhibitory effect on that induced by arachidonic acid, collagen, platelet-activating factor (PAF) or U46619. YD-3 also suppressed generation of inositol phosphates caused by thrombin. On the other hand, thrombin-induced fibrin formation was not affected by YD-3, indicating YD-3 does not inhibit the proteolytic activity of thrombin. 3. In washed human platelets, however, YD-3 had only mild inhibitory effect on the low concentration (0.05 u ml(-1)) of thrombin-induced human platelet aggregation, and did not affect that induced by higher concentrations (> or =0.1 u ml(-1)) of thrombin or SFLLRN, the protease-activated receptor 1 (PAR1) agonist peptide. By contrast, YD-3 inhibited both human and rabbit platelet aggregation elicited by trypsin with IC(50) values of 38.1 microM and 5.7 microM, respectively. 4. YD-3, at 100 microM, had no effect on ristocetin-induced glycoprotein Ib (GPIb)-dependent aggregation of human platelets. In addition, platelets treated with chymotrypsin, which cleaves GPIb, enhanced rather than attenuated the inhibition of YD-3 on thrombin-induced human platelet aggregation. These data indicate that GPIb plays no role in the antiplatelet effect of YD-3. 5. In SFLLRN-desensitized human platelets, high concentration of thrombin (1 u ml(-1)) could still elicit intracellular Ca(2+) mobilization, and the rise of [Ca(2+)](i) was prevented by either leupeptin or YD-3. 6. Our results suggest that YD-3 inhibits a non-PAR1 thrombin receptor which mediates the major effect of thrombin in rabbit platelets, but in human platelets, this receptor function becomes significant only when the function of PAR1 has been blocked or attenuated.

Animals↗

PubMed2000

Abnormal activation of K(+) channels in aortic smooth muscle of rats with endotoxic shock: electrophysiological and functional evidence.

1. This study examined the role of K(+) channels in vascular hyporeactivity of rats with endotoxic shock ex vivo. 2. At the end of the in vivo experiments, thoracic aortas were removed from endotoxaemic and control rats. After removal of the endothelium, aortic segments were mounted in myographs for recording of isometric tension and smooth muscle membrane potential. 3. Membrane potentials recorded from endotoxaemic rats were hyperpolarized compared to those of the controls. This hyperpolarization was partially reversed by tetraethylammonium, charybdotoxin or glibenclamide, but not significantly affected by apamin. The hyperpolarization was also partially attenuated by N(omega)-nitro-L-arginine methyl ester (L-NAME) or 1H:-[1,2,4]oxadiazolo[4,3-a]quinoxalin-l-one (ODQ). 4. In phenylephrine-contracted aortic rings, both agonists of K(+) channels, NS1619 and pinacidil, induced greater relaxations and re-polarizations in the preparations obtained from endotoxaemic rats. The NS1619-induced relaxation and re-polarization in arteries from endotoxaemic rats were partially inhibited by tetraethylammonium and completely inhibited by charybdotoxin, L-NAME or ODQ, but not significantly affected by apamin. Similarly, the greater relaxation and re-polarization induced by pinacidil in arteries from endotoxaemic rats were also inhibited by glibenclamide, L-NAME or ODQ. However, these inhibitors had no significant effect on relaxations and re-polarizations induced by NS1619 and pinacidil in arteries from controls. 5. This study provides the electrophysiological and functional evidence showing an abnormal activation of K(+) channels in vascular smooth muscle in animals with endotoxic shock. Our observations suggest that overproduction of nitric oxide causes an activation of large conductance Ca(2+)-activated K(+) channels and ATP-sensitive K(+) channels which contributes to endotoxin-mediated vascular hyporeactivity.

Animals↗

PubMed2000

Chromosomal changes and clonality relationship between primary and recurrent hepatocellular carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is highly malignant and prone to recur after surgical treatment. Differentiation between a true relapse of HCC and a second primary tumor is of clinical importance. However, no convenient method is currently available. METHODS: Comparative genomic hybridization (CGH) was used to analyze 31 pairs of initial and recurrent HCC samples obtained from patients undergoing 2 consecutive surgeries. The resulting chromosomal aberration profiles were used as genomic fingerprints to determine tumor clonalities and their relationships. RESULTS: Eleven recurrent tumors with high clonal relationship (CR) values (>0.95) were found to be relapsed HCCs, and 11 tumors with CR values close to 0 were found to be second primary HCCs. The other 9 paired samples had inconclusive CR values between 0.95 and 0.4. Two were confirmed by hepatitis B virus integration and X chromosome inactivation analysis to be de novo cancers (CR values, 0.35 and 0. 23, respectively). Initial HCCs that subsequently relapsed accumulated more chromosomal aberration events than those that developed de novo HCC (mean, 16.1 +/- 4.5 vs. 5.4 +/- 4.8 events; P < 0.01). Also, they more frequently showed gains on chromosome arms 3q, 6p, 8q, and 17q and losses on 4q and 16p. CONCLUSIONS: CGH is useful for chromosomal aberration study and tumor clonality analysis. More and characteristic genomic changes in the initial HCC suggest that subsequent tumor recurrence is a true relapse.

Adult↗

PubMed2000

Ascorbic acid supplementation improved antibody response to infectious bursal disease vaccination in chickens.

The purpose of the present study was to determine if supplementation of ascorbic acid (AA) to the diet would have a beneficial effect on infectious bursal disease (IBD) vaccination of chickens for protection against infectious bursal disease virus (IBDV) infection. Two hundred forty specific pathogen-free (SPF) chickens were divided into eight experimental groups. A 2 x 2 x 2 factorial arrangement in a completely randomized design was used; AA supplementation at 1,000 ppm in the diet, vaccination, and challenge were the main effects. Prior to challenge and 10 d after challenge, serum AA concentration, serum corticosterone concentration, ELISA antibody titer to IBDV, body weight, bursa-to-body weight (B:B) ratio, and bursal histological score (BHS) were determined. Nonvaccinated chickens fed a diet supplemented with AA did not exhibit clinical signs or mortality following challenge, whereas AA-unsupplemented counterparts had 100% cumulative morbidity and 30% cumulative mortality. Serum AA levels of AA-supplemented and vaccinated chickens were significantly (P < 0.05) higher than AA-unsupplemented and vaccinated chickens. Fourteen days following vaccination, significantly (P < 0.05) higher ELISA titers to IBDV were observed in vaccinated chickens supplemented with AA as compared to AA-unsupplemented counterparts. Ascorbic acid-supplemented chickens, especially those also vaccinated, had higher body weight gains as compared to the AA-unsupplemented chickens. Ascorbic acid-supplemented chickens challenged with IBDV did not show any clinical signs or mortality. The results suggest that supplementation of AA at 1,000 ppm in the diet has beneficial effects on antibody response to IBD vaccination and body weight gain.

Animals↗

PubMed2000

Treatment of deltoid contracture in adults by distal release of the deltoid.

Twenty-five consecutive adult patients (32 shoulders) with deltoid contracture were treated with distal release and followed up for an average of 4 years (range, 2-8 years). All shoulders achieved full range of motion and complete relief of pain and deformity after 3 months. No muscle weakness was clinically evident. In addition, another five adult patients (nine shoulders) with deltoid contracture were treated with distal release and quantitative measurement of muscle power recovery around the shoulder with Cybex 340 dynamometer before surgery, and 3 months and 1 year after surgery. Isokinetic peak torque of shoulder muscles did not decrease significantly at either 60 degrees per second or 180 degrees per second angular velocity after surgery. In addition, the shoulder extensors showed a twofold increase of isokinetic peak torque after surgical release of deltoid contracture. Distal release was a simple and effective surgical technique to treat deltoid contracture in adults. All patients in this series achieved a satisfactory outcome.

Adult↗

PubMed2000

Biomechanical comparison for different configurations of tension band wiring techniques in treating an olecranon fracture.

BACKGROUND: The aim of this study was to compare the superiority between the newly designed modified AO tension band wiring technique and the traditional modified AO tension band wiring technique in treating an olecranon fracture. METHODS: Eight pairs of fresh cadaveric ulnae were tested biomechanically. After transverse osteotomy of the olecranon, all left ulnae were fixed by the traditional modified AO technique with two Kirschner wires inserted through the anterior ulnar cortex and all right ulnae by the new technique with two Kirschner wires inserted into the marrow cavity from the olecranon to the ulnar styloid process. All specimens were tested by the Material Testing System machine to evaluate fragment displacement and the maximal failure load. A dual linear variable displacement transducer was used to measure relative minimal displacement. RESULTS: There was no significant difference between the techniques. The maximal failure load by either technique was more than 80 kg. Even at testing failure, no Kirschner wires migrated proximally. CONCLUSION: The new technique may be applied widely to treat all olecranon fractures, because it is a technically easier and safer technique. Less than 5.5-kg loads could be permitted in daily activity postoperatively. A single tolerable loading weight should not exceed 8 kg. Kirschner wires will not migrate proximally, despite increased joint loading. Clinically, this study may confirm indirectly the hypothesis that proximal migration of Kirschner wires was mainly due to triceps traction.

Adolescent↗

PubMed2000

Terbutaline prevents circulatory failure and mitigates mortality in rodents with endotoxemia.

Septic shock is characterized by a decrease in systemic vascular resistance. Nevertheless, regional increases in vascular resistance can occur that may predispose mammals to organ dysfunction, including the acute respiratory distress syndrome. In the host infected by endotoxin (lipopolysaccharide, LPS), the expression and release of proinflammatory tumor necrosis factor-alpha (TNFalpha) rapidly increases, and this cytokine production is regulated by agents elevating cyclic AMP. In this report, we present evidence that terbutaline, a beta2-agonist, inhibits TNFalpha production and enhances interleukin-10 (IL-10) release in the anesthetized rat treated with LPS. In addition, an overproduction of nitric oxide (NO, examined by its metabolites nitrite/nitrate) by inducible NO synthase (iNOS, examined by western blot analysis) is attenuated by pretreatment of LPS rats with terbutaline. Overall, pretreatment of rats with terbutaline attenuates the delayed hypotension and prevents vascular hyporeactivity to norepinephrine. In addition, pretreatment of mice with terbutaline also improves the survival in a model of severe endotoxemia. The infiltration of polymorphonuclear neutrophils into organs (e.g., lung and liver) from the surviving LPS mice treated with terbutaline was reduced almost to that seen in the normal controls. These findings suggest that the inhibition of TNFalpha and NO (via iNOS) production as well as the increment of IL-10 production contribute to the beneficial effect of terbutaline in animals with endotoxic shock.

Acetylcholine↗