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Biomedical subjects

C C Wu

Publications and source records attributed to C C Wu.

At least 91 records · Page 5Linked to original sources
PubMed2001

Huge cystic duplication of the ascending colon in adult.

Duplications of alimentary tract are uncommon congenital anomalies that are usually identified during the pediatric age. However, a minority of cases remain unsuspected until adulthood. They may be cystic or tubular in appearance and characteristically arise from the mesenteric border of the intestine. This paper reports a 37-year-old male with a huge cystic duplication of the ascending colon. In facing such a huge abdominal cystic tumor, differential diagnoses including duplication cyst, mesenteric cyst, choledochal cyst, giant diverticulum, and cystic tumor of the pancreas should be considered. Computerized tomography is a good tool for delineating the relationship between the tumor and peripheral structures. Surgery not only provides treatment but also final pathological diagnosis. Complete resection of a colonic duplication is necessary because of potential malignant change of the lesion.

Adult↗
PubMed2001

Extra-articular deformity in distal radial fractures treated by external fixation.

OBJECTIVE: To determine the radiographic outcome in fractures of the distal radius treated with closed reduction and external fixation. DESIGN: A retrospective study. SETTING: The orthopedic department of National Taiwan University Hospital. PATIENTS: Eighty-five consecutive patients (36 female, 49 male), average age 48 years, with fractures of the distal radius seen between March 1995 and June 1998. INTERVENTIONS: Closed reduction and external fixation of fractures, followed up by good-quality posteroanterior and lateral radiographs to evaluate healing. MAIN OUTCOME MEASURES: Radial height, radial inclination and volar tilt were measured on radiographs obtained initially, immediately postoperatively and at the time of removal of external fixation. Data were analyzed by the t-test. RESULTS: Immediately after reduction and fixation, there was a significant improvement in the measurements of radial height and radial inclination. This improvement was gradually lost and height and inclination were significantly decreased at the time the external fixation device was removed. External fixation did not improve the volar tilt. CONCLUSION: External fixation is a popular method to improve the reduction of osseous deformity but cannot effectively protect comminuted distal radial fractures from loss of reduction, which may be associated with shortening and redisplacement.

Congenital Abnormalities↗
PubMed2001

Tumor necrosis factor promoter polymorphisms in patients with rheumatoid arthritis in Taiwan.

OBJECTIVE: To investigate the association of tumor necrosis factor (TNF) promoter polymorphisms with rheumatoid arthritis (RA) in Taiwan. METHODS: TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were determined in 97 patients with RA and 97 healthy controls using the PCR-RFLP method. RESULTS: The phenotypic frequency of TNF-308A was significantly lower in patients with RA than in healthy controls. This finding can only be found in HLA-DR4 negative patients, not in DR4 positive RA patients and controls. The TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were not related to the clinical manifestations of RA patients. CONCLUSION: TNF-308A itself or a neighboring gene may be a protective factor for the development of RA in the HLA-DR4 negative population in Taiwan. TNF promoter polymorphisms were not associated with the clinical manifestations of patients with RA in Taiwan.

Arthritis, Rheumatoid↗
PubMed2001

Transesophageal echocardiography in the anesthetic management of total hip arthroplasty.

Total hip arthroplasty is a common procedure in the elderly and thromboembolism continues to be a cause of mortality and morbidity associated with this procedure. When properly diagnosed and treated the mortality rate from pulmonary embolism can be reduced significantly. Transesophageal echocardiograpic (TEE) detection of central pulmonary artery thromboemboli in patients with severe pulmonary embolism has been reported to have a sensitivity of 96.7% and a specificity of 88%. However TEE is not universally available due to its cost and expertise that is required. Taking into consideration its cost/effectiveness we suggest that in patients undergoing the cement type of total hip arthroplasty who are cardiopulmonary compromised, debilitated or elderly the use of TEE is indicated.

Anesthesia↗
PubMed2001

Effect of charge neutralization on the dewatering performance of alum sludge by polymer conditioning.

Cationic and anionic polymers with the same molecular weight were used as sludge conditioning reagent to study the polymer charge effect on alum sludge dewatering characteristics. On the basis of capillary suction time, bound water content, and zeta-potential measurement in this study, the function of charge neutralization appears to be an important consideration in the sludge dewaterability and moisture content. Using the dilatometric technique to measure the bound water content, we found that alum sludge conditioned by cationic polymer presented more significant variation in the bound water content than sludge subject to anionic conditioning. We hypothesise that the mechanism of charge neutralization caused much water depletion by replacement and exclusion in sludge and results in the decrease of bound water within the cationic polymer conditioning. An insignificant bound water variation found during the anionic conditioning resulted from the lack of charge neutralization. A lighter and looser floc structure is also be found in the anionic conditioned sludge after the analysis of wet floc density and fractal dimension. Such open floc structure can be attributed to the lack of charge neutralization as the flocs aggregate with anionic polymer.

Adjuvants, Immunologic↗
PubMed2001

Femoral reconstruction.

Reconstruction of the femur is sometimes difficult in patients that may sustain long-term disabilities. Following advancements in modern technology, some femoral disorders which were considered to be recalcitrant in the past can now be treated with satisfactory outcomes. This article reviews the experience of femoral reconstruction at the Orthopedic Department of Chang Gung Memorial Hospital (Linkou). Reconstruction of the femur includes nonunion, malunion, and segment bony defects that require bone transfer. The prerequisite for successful treatment was to follow the biological and biomechanical principles. The author believes that the technique of femoral reconstruction can be developed and simplified so that success rates can be further improved.

Biomechanical Phenomena↗
PubMed2001

Mamu-DQA1 allele and genotype frequencies in a randomly sampled breeding colony of rhesus macaques (Macaca mulatta).

We studied the allelic and genotypic distribution of the major histocompatibility class-II locus DQA1 observed in a random sample of Indian rhesus macaques (Macaca mulatta) from a major breeding facility in the United States. The DNA was isolated from whole blood samples collected between 1991 and 1994 from 65 Indian rhesus monkeys. Polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP), which involves use of specific amplification of DQA1 exon 2 and subsequent restriction digestion of the 242-base pair fragment, was used to genotype the animals for the 20 known macaque (Mamu)-DQA1 alleles. Frequencies for four alleles (DQA1*240x, *2502, *2503 and *0102) differed significantly from those reported in a smaller sample of rhesus macaques from the German Primate Center. The modest genetic survey of Mamu-DQA1 genotypes presented here will be particularly useful in designing epidemiologic studies that investigate associations between immunogenetic background and disease susceptibility in macaque models of human disease.

Alleles↗
PubMed2000

Study the mechanisms of U-50,488 to prevent the development of morphine tolerance in guinea pigs.

Previously we have shown that low dose of [trans-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-benzeneacetamide hydrochloride] (U-50,488) could prevent the development of morphine tolerance in guinea pigs. In the present study we tried to investigate the role of glutamate and nitric oxide in this process. Male Hartley guinea pigs (200-300 g) were chronically treated s.c. with either saline or morphine (15 mg/kg) or morphine + U-50,488 (0.003 mg/kg) twice a day for 7 days. Antinociceptive activity was assessed by hot-plate test on the first, fourth and seventh day. Spinal cord slices (450 microm) were prepared 30 min after drug treatment on eighth day and [3H] glutamate and nitric oxide (NO) released were determined. We found that coadministration of U-50,488 (0.003 mg/kg) suppressed the development of morphine tolerance to antinociceptive effect as we reported before. The percentage of in vitro spinal release of [3H] glutamate by 100 microM morphine was significantly higher in the chronic morphine group than the control group. On the other hand, coadministration of U-50,488 with morphine for 7 days blocked this effect significantly. The basal NO level released from the spinal cord slices was significantly higher in chronic morphine group but not in chronic (morphine + U-50,488) group. In vitro morphine (100 microM) increased the NO level in control group and chronic (morphine + U-50,488) group and also further increased NO in chronic morphine group. From the NMDA-displaced [3H] glutamate binding in guinea pig spinal cord, we found that the Bmax decreased in chronic morphine group but not in the chronic (morphine + U-50,488) group. In conclusion, chronic morphine treatment may activate the NMDA receptors by increasing the release of glutamate which causes the increase of synthesis and release of NO and following uncertain mechanisms to induce the development of morphine tolerance. And the mechanisms of U-50,488 to prevent the development of morphine tolerance may involve the inhibition of glutamate released by chronic morphine and also the decrease of NO induced by chronic morphine.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed2000

Hyperpolarization contributes to vascular hyporeactivity in rats with lipopolysaccharide-induced endotoxic shock.

We have examined the role of membrane hyperpolarization in mediating vascular hyporeactivity induced by bacterial lipopolysaccharide (LPS) in endothelial-denuded strips of rat thoracic aorta ex vivo. The injection of rats with LPS caused a significant fall of blood pressure and a severe vascular hyporeactivity to norepinephrine. The membrane potential recording showed that endotoxemia caused a hyperpolarization when compared to the control. This hyperpolarization was fully restored by methylene blue (MB; 10 microM) and partially reversed by Nomega-nitro-L-arginine methyl ester (L-NAME; 0.3 mM), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 1 microM), tetraethylammonium (TEA; 10 mM), charybdotoxin (CTX; 0.1 microM), or glibenclamide (GB; 10 microM), however, this hyperpolarization was not significantly affected by apamin (0.1 microM), 4-aminopyridine (4-AP; 1 mM), or Ba2+ (50 microM). In addition, the basal tension of the tissues obtained from endotoxemic rats was enhanced by the following order: MB > or = ODQ > TEA > or = L-NAME > or = CTX > GB; whereas apamin, 4-AP or Ba2+ had no significant effects on these tissues. In contrast, none of these inhibitors had significant effects on the membrane potential or the basal tension in control tissues. Our electrophysiological results further confirmed previous studies showing that in addition to nitric oxide, the large conductance Ca2+-activated K+-channels and ATP-sensitive K+-channels are, most likely, responsible for endotoxin-mediated hyporeactivity to vasoconstrictor agents in vascular smooth muscle.

Animals↗
PubMed2000

Extracellular Bartonella henselae and artifactual intraerythrocytic pseudoinclusions in experimentally infected cats.

Blood, spleen and liver of specific pathogen-free (SPF) cats and SPF cats experimentally infected with Bartonella henselae were examined. Using immunohistochemical labeling, no intracellular B. henselae were observed in tissues of any cats, but extracellular B. henselae were detected in tissues of infected cats. Pseudoinclusions were detected in erythrocytes of all cats using electron microscopy.

Animals↗
PubMed2000

Antimicrobial susceptibility of Mycoplasma hyorhinis.

A broth microdilution technique was used to determine the antimicrobial susceptibility of 15 field isolates of Mycoplasma hyorhinis to 10 antimicrobial agents, representative of different classes, and contrasting newer agents to existing ones. For the macrolides, the MIC(90) for tylosin and tilmicosin was 1 and 4 microg/ml, respectively, but was > or = 16 microg/ml for erythromycin. Tetracycline, lincomycin and enrofloxacin each had an MIC(90) of 2 microg/ml. The mycoplasma had similar levels of susceptibility to the aminoglycoside and aminocyclictol classes exhibiting an MIC(90) of 4 microg/ml for gentamicin and 2 microg/ml for spectinomycin. The isolates exhibited high MICs to trimethoprim/sulfamethoxazole with an MIC(90) > or = 16/304 microg/ml. In summary, M. hyorhinis isolates from the US had low MICs against a variety of antimicrobials tested, with the exception of erythromycin and trimethoprim/sulfamethoxazole.

Animals↗
PubMed2000

Comparison of simultaneous dobutamine echocardiography and thallium-201 stress-reinjection single-photon emission computed tomography in predicting improvement of chronic myocardial dysfunction after revascularization.

Previous studies have shown that ultrasonic integrated backscatter is valuable in characterizing stunned myocardium. Recent investigations have demonstrated that resting cardiac cycle-dependent variation of integrated backscatter closely paralleled the contractile reserve in patients with chronic left ventricular ischemic dysfunction. The purpose of this study was to validate whether ultrasonic tissue characterization (UTC) compared with dobutamine stress echocardiography (DSE) and thallium-201 stress-reinjection single-photon emission computed tomography (Tl-SPECT) could predict reversible myocardial dyssynergy in patients with chronic coronary artery disease. Forty-eight patients with stable coronary artery disease underwent UTC, DSE, and Tl-SPECT simultaneously before successful coronary revascularization and were followed up with echocardiograms at rest >3 months later. Among the 58 investigated segments, the weighted amplitude, a composite parameter derived from the integrated backscatter power curve, was larger for those groups with greater functional recovery (p <0.001). For the persistent akinetic segments, the weighted amplitudes were small with large deviations of the nadir ratios that represented the asynchrony between the intramural contractile events and the global systole. Using the cut-off value 2.0 of the weighted amplitude, the sensitivity and specificity for predicting functional improvement after revascularization were both 82.8% (kappa = 0.66) and comparable to the sensitivity and specificity of DSE and Tl-SPECT. UTC, delineating the myocardial physical state and intramural contraction, can be a novel approach in predicting functional improvement of chronic dyssynergy after revascularization.

Adult↗
PubMed2000

Effect of ascorbic acid supplementation on the immune response of chickens vaccinated and challenged with infectious bursal disease virus.

One-day-old chickens were divided into two groups and reared under similar conditions. One group was fed a diet supplemented with 1000ppm ascorbic acid and the other group was fed an identical diet, but not supplemented with ascorbic acid. Both groups were vaccinated against infectious bursal disease (IBD) at 7 days of age and challenged orally with 4x10(5) of 50% embryo-lethal-dose IBDV 14 days later. The number of anti-IBDV antibody secreting cells, production of interleukin-2 (IL-2) by splenocytes, number of CD4(+), CD8(+) and IgM(+) cells in spleen and IgM(+) cells in bursa of Fabricius were compared between the two groups at 7 days (prior to vaccination), 21 days (14 days post-vaccination and prior to challenge) and 31 days (10 days post-challenge) of age. The number of CD8(+) in spleen at 7 days of age and IgM(+) cells in bursa at 7, 21 and 31 days of age were significantly higher in ascorbic acid supplemented group (P<0.05). Production of IL-2 by splenocytes was higher as indicated by higher stimulation indices in ascorbic acid supplemented group. The number of anti-IBDV IgG antibody secreting cells in spleen at 21 and 31 days of age were significantly higher in ascorbic acid supplemented group (P<0.05). Dietary supplementation of ascorbic acid may ameliorate the immunosuppression caused by IBDV vaccination and improve humoral and cellular immune responses.

Animals↗
PubMed2000

Antiangiogenic effects of S-nitrosocaptopril crystals as a nitric oxide donor.

Angiogenesis is the formation of new capillaries from preexisting vessels by migration and proliferation of endothelial cells, which produce a cellular signaling messenger, nitric oxide (NO). The purpose of the present study was to examine the effects of exogenous NO donors on angiogenesis by using a novel crystalline NO donor, S-nitrosocaptopril. The characteristic X-ray diffraction pattern of S-nitrosocaptopril was demonstrated for the first time. On primary capillary endothelial cells pretreated with vascular endothelium growth factor (VEGF), S-nitrosocaptopril (1-500 microM), but not captopril, produced a dose-dependent inhibition of endothelial proliferation. On chick embryos of entire living eggs, gelatin sponges adsorbed with VEGF were implanted on the embryo chorioallantoic membrane to promote vascular growth activity within the sponges. Addition of S-nitrosocaptopril crystals (0.1 mg) to the gelatin sponges markedly reduced vascular density around the sponges, whereas captopril did not inhibit neovascularization. The vascular hemoglobin content surrounding each of the gelatin sponges was determined as a confirmatory test. S-nitrosocaptopril, but not captopril, significantly decreased the hemoglobin content of the embryo tissues immediately surrounding the gelatin sponges. In conclusion, S-nitrosocaptopril exerts an inhibitory effect on angiogenesis. This newly discovered function of S-nitrosocaptopril appears to be governed by distinct structural NO moiety.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2000

Ontogeny of the tectorotundal pathway in chicks (Gallus gallus): birthdating and pathway tracing study.

The avian tectorotundal system has been suggested as a homologue of the mammalian colliculopulvinar system. In the tectorotundal system, neurons of the stratum griseum centrale (SGC) of the optic tectum send their axons bilaterally to the nucleus rotundus (Rt). In transit to the Rt, the axons of the SGC neurons collateralize in the nuclei posteroventralis thalami (PV), subpretectalis (SP), and interstitiopretectosubpretectalis (IPS) of the tectothalamic tract (TT). The current study used birthdating and pathway-tracing methods to investigate the neurogenesis and time course of neuronal connections of the tectorotundal pathway in chicks during embryogenesis. By using tritiated thymidine autoradiography, we observed that the SGC neurons of the tectum were generated by embryonic days 3.0-5.5 (E3.0-E5.5), the Rt by E3.5-E5.0, and the nuclei of TT by E3.5-4.5. To trace the tectorotundal pathway, we injected cholera toxin B subunit (CTb) into the tectum, and the CTb-like immunoreactivity was examined. By E4.5-E5.5, some CTb-like immunoreactive (CTb-LI) axons terminated in the ipsilateral SP/IPS. By E6.0-E6.5, CTb-LI axon bundles were seen ipsilaterally in the TT. Increased numbers of labeled axons were seen terminating in the SP/IPS. By E7.0-E7.5, heavily labeled axons in the TT were observed with diffuse terminals in areas ventral to the presumptive Rt and PV. By E7.5-E8.0, the tectal axons innervated the ipsilateral Rt, in which some of the collaterals crossed the midline to the contralateral diencephalon. The crossed tectorotundal projection was seen first by E8.0-E8.5. Also, during this stage, a few CTb-LI collaterals terminated in the contralateral SP/IPS. Between E10 and E13, the pattern of bilateral tectorotundal projections became more regionalized, whereas labeling continued to increase in the SP/IPS. At E16, the labeling pattern of all tectorecipient structures resembled that of the hatchling. The current study revealed the temporal order of development of the tectorotundal pathway during embryogenesis. The SGC cells first innervate ipsilaterally the SP/IPS and then the Rt/PV. The schedule of the crossed tectorotundal connections coincides with the schedule of tectal projections onto the contralateral intrinsic nuclei of the TT. We conclude that E8.0 (+/- E0.5) is a critical stage for the development of the tectofugal pathway. Moreover, the current study provides important insights into the relative ontogeny of the mammalian tectofugal pathway.

Animals↗
PubMed2000

An appraisal of liver and portal vein resection for hepatocellular carcinoma with tumor thrombi extending to portal bifurcation.

BACKGROUND: The role of surgical resection for hepatocellular carcinoma with tumor thrombi involving the major portal vein is controversial because of a high operative risk and poor prognosis. Previously, a resection was performed only when the tumor thrombi were limited to the first branch of the portal vein without extension to the portal bifurcation. HYPOTHESIS: Concomitant liver and portal vein resection may be beneficial in patients with hepatocellular carcinoma with tumor thrombi extending to portal bifurcation. DESIGN: Retrospective review. SETTING: University hospital, tertiary referral center. PATIENTS: Among 368 patients with hepatocellular carcinoma who underwent a curative resection, portal vein involvement occurred in 112 patients. Fifteen of the 112 patients underwent a concomitant liver and portal vein resection owing to extension of tumor thrombi to the portal bifurcation (group 1). The remaining 97 patients did not need portal vein resection (group 2). INTERVENTION: Surgical indications, procedures, and results of pathological examination of resected specimens were assessed in patients in group 1. The clinicopathological characteristics, operative morbidity and mortality, and operative results were compared between the 2 groups. MAIN OUTCOME MEASURES: Disease-free and actuarial survival rates. RESULTS: Intramural tumor infiltration was found at the site of thrombi adhesion to the portal vein cuff in 11 of 15 patients in group 1. Owing to patient selection bias, patients in group 1 were significantly younger and had better liver function and greater resected liver weight. The operative time, postoperative hospitalization, operative blood loss, amount of blood transfusion, and operative morbidity and mortality did not differ significantly between the 2 groups. The 5-year disease-free survival rates of groups 1 and 2 were 21.6% and 20.4% (P =.19), respectively, while the actuarial survival rates were 26. 4% and 28.5% (P =.33), respectively. CONCLUSION: Liver resection with partial resection of the portal vein is justified in selected patients with hepatocellular carcinoma with tumor thrombi extending to portal bifurcation.

Carcinoma, Hepatocellular↗
PubMed2000

Surgical treatment for recurrent hepatocellular carcinoma with tumor thrombi in right atrium: using cardiopulmonary bypass and deep hypothermic circulatory arrest.

Tumor in the right atrium creates a life-threatening condition and should be removed immediately. A cirrhotic patient who had recurrent hepatocellular carcinoma (HCC) over remnant liver with tumor thrombi extending to inferior vena cava (IVC) and right atrium presented with impending congestive heart failure. The recurrent tumor and its thrombi were successfully resected en-bloc using cardiopulmonary bypass and hypothermic circulatory arrest. Although the patient's disease-free and actual survival time were only 6 months and 14 months, respectively, he was rescued from heart failure. This aggressive surgical strategy creates further possibility to treat such advanced HCC cases. Further investigations regarding adjuvant therapies in these circumstances, however, are necessary.

Adult↗