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Biomedical subjects

C-C Yang

Publications and source records attributed to C-C Yang.

10 recordsLinked to original sources
PubMed2006

Electrolyzed-reduced water reduced hemodialysis-induced erythrocyte impairment in end-stage renal disease patients.

Chronic hemodialysis (HD) patients increase erythrocyte susceptibility to hemolysis and impair cell survival. We explored whether electrolyte-reduced water (ERW) could palliate HD-evoked erythrocyte impairment and anemia. Forty-three patients undergoing chronic HD were enrolled and received ERW administration for 6 month. We evaluated oxidative stress in blood and plasma, erythrocyte methemoglobin (metHb)/ferricyanide reductase activity, plasma metHb, and proinflammatory cytokines in the chronic HD patients without treatment (n=15) or with vitamin C (VC)- (n=15), vitamin E (VE)-coated dialyzer (n=15), or ERW treatment (n=15) during an HD course. The patients showed marked increases (15-fold) in blood reactive oxygen species, mostly H(2)O(2), after HD without any treatment. HD resulted in decreased plasma VC, total antioxidant status, and erythrocyte metHb/ferricyanide reductase activity and increased erythrocyte levels of phosphatidylcholine hydroperoxide (PCOOH) and plasma metHb. Antioxidants treatment significantly palliated single HD course-induced oxidative stress, plasma and RBC PCOOH, and plasma metHb levels, and preserved erythrocyte metHb /ferricyanide reductase activity in an order VC>ERW>VE-coated dialyzer. However, ERW had no side effects of oxalate accumulation easily induced by VC. Six-month ERW treatment increased hematocrit and attenuated proinflammatory cytokines profile in the HD patients. In conclusion, ERW treatment administration is effective in palliating HD-evoked oxidative stress, as indicated by lipid peroxidation, hemolysis, and overexpression of proinflammatory cytokines in HD patients.

Adult↗
PubMed2006

Hyperhomocysteinaemia and vascular access thrombosis among chronic hemodialysis patients in Taiwan: a retrospective study.

Vascular access thrombosis (VAT) is an important cause of morbidity for chronic haemodialysis (HD) patients. Some risk factors for VAT have been well-defined for chronic HD patients from western countries. However, only a few such factors have been confirmed for Taiwanese patients. This study attempted to determine the association between hyperhomocysteinaemia and the incidence of VAT for chronic HD patients in Taiwan. We retrospectively enrolled a total of 196 patients into this study during 2003. The patients were separated into VAT (n = 142) and control (n = 54) group. The participants of the VAT group were identified as those having one or more VAT, and the participants of the control group were those with no VAT in the past. The mean follow-up period was 48 months. The mean serum homocysteine levels were 29.5 +/- 9.6 and 29.1 +/- 9.5 micromol/l for the VAT (n = 142) and the control (n = 54) group, respectively. There was no significant difference in the level of homocysteine between the VAT and the control group (p = 0.70). Female chronic HD patients had significantly greater mean total homocysteine levels than male (30.89 micromol/l, 95% CI 28.84-32.94 vs. 28.06 micromol/l, 95% CI 26.32-29.82, respectively, p = 0.038). That synthetic graft was a significant risk factor for VAT was determined using multivariate logistic regression analysis. There was no association between serum total homocysteine levels and the incidence of VAT in chronic HD patients in Taiwan.

Aged↗
PubMed2006

Anticardiolipin antibodies and vascular access thrombosis in Taiwanese haemodialysis patients with chronic hepatitis C: a retrospective study.

Hepatitis C virus causes various extrahepatic immunologic abnormalities. Vascular access thrombosis (VAT) is a major cause of morbidity in chronic haemodialysis (HD) patients. Immunoglobulin-G anticardiolipin antibody (IgG-ACA) is strongly associated with venous and arterial thrombosis in patients with normal renal function. Previous investigations have reported the association of raised IgG-ACA titre recurrent with VAT in HD patient, and also few equivalent studies were reported the same in Taiwan. This study attempted to determine whether raised IgG-ACA titres are associated with increased risk of recurrent VAT in HD patients with chronic hepatitis C. This study enrolled 98 chronic hepatitis C patients undergoing HD. IgG-ACA titre and hepatitis C marker were measured for all subjects. Raised IgG-ACA titres were present in 29.6% (29/98) of patients. In both groups (raised and normal IgG-ACA), the type of shunt did not differ (p = 0.416). There was strong association between raised IgG-ACA titre and recurrent VAT (p = 0.0004). In predicting for more or one episodes of VAT using multiple logistic regression, synthetic graft (p < 0.0001), raised IgG-ACA titre (p = 0.039), presence of hepatitis B (p = 0.004) and haemodialysis duration (p = 0.039) were significant factors. The prevalence of raised IgG-ACA titres was 39.6% among chronic hepatitis C with HD patients. There was strong association between raised IgG-ACA titre and recurrent VAT, and this finding may be the consequence of pathogenetic role of raised IgG-ACA titres on the development of VAT status in HD patients with chronic hepatitis C.

Antibodies, Anticardiolipin↗
PubMed2006

Effects of vitamin C infusion and vitamin E-coated membrane on hemodialysis-induced oxidative stress.

Chronic hemodialysis (HD) patients manifest anemia and atherosclerosis with associated oxidative stress. We explored whether intravenous infusion of vitamin C (VC) and/or use of vitamin E (VE)-coated dialysis membrane could palliate HD-evoked oxidative stress. Eighty patients undergoing chronic HD were enrolled and randomly assigned into four groups: HD with intravenous VC (n=20), HD with VE-coated dialyzer (n=20), HD with both (n=20), and HD with neither (n=20). We evaluated oxidative stress in blood and plasma, erythrocyte methemoglobin/ferricyanide reductase (red blood cells (RBC)-MFR) activity, plasma methemoglobin, and pro-inflammatory cytokines in these patients. All patients showed marked increases (14-fold) in blood reactive oxygen species (ROS) after HD. The types of ROS were mostly hydrogen peroxide, and in lesser amounts, O2*- and HOCl. HD resulted in decreased plasma VC, total antioxidant status, and RBC-MFR activity and increased plasma and erythrocyte levels of phosphatidylcholine hydroperoxide (PCOOH) and methemoglobin. Intravenous VC significantly palliated HD-induced oxidative stress, plasma and RBC levels of PCOOH, and plasma methemoglobin levels and preserved RBC-MFR activity. The VE-coated dialyzer effectively prevented RBCs from oxidative stress, although it showed a partial effect on the reduction of total ROS activity in whole blood. In conclusion, intravenous VC plus a VE-coated dialyzer is effective in palliating HD-evoked oxidative stress, as indicated by hemolysis and lipid peroxidation, and by overexpression of proinflammation cytokines in HD patients. Using VE-coated dialyzer per se is, however, effective in reducing lipid peroxidation and oxidative damage to RBCs.

Antioxidants↗
PubMed2005

Anticardiolipin antibody and Taiwanese chronic haemodialysis patients with recurrent vascular access thrombosis.

Vascular access failure is a major cause of morbidity in chronic haemodialysis (HD) patients. However, some factors (such as homocysteine levels) are known regarding the risk factors predisposing certain HD patients to vascular access thrombosis (VAT). Immunoglobulin-G anticardiolipin antibody (IgG-ACA) is strongly associated with venous and arterial thrombosis in patients with normal renal function. Previous investigations have reported the characteristics of patients with raised IgG-ACA titre and recurrent VAT of HD in Western countries, but few equivalent studies exist for Taiwan. This retrospective study attempts to determine whether raised IgG-ACA titres are associated with an increased risk of recurrent VAT in chronic HD patients. This study enrolled 483 patients undergoing HD. IgG-ACA titre and hepatitis B&C marker were measured for all patients. A history of recurrent (VAT more than one) and/or VAT was elicited by using information from the patient questionnaires and was verified by means of careful inpatient and outpatient chart review. Raised IgG-ACA titres were present in 21.7% (105/483) of patients. In both groups (raised IgG-ACA and normal IgG-ACA), the type of shunt differed significantly (p = 0.029). In predicting for more or one episodes of VAT by using multiple logistic regression with all significant factors, synthetic graft was also a significant factor (p < 0.0001). The 105 raised IgG-ACA titres and 378 normal IgG-ACA titres were associated between chronic HD patients and recurrent VAT (p = 0.034). In predicting for more or one episode of VAT by using multiple logistic regression with all significant factors, raised IgG-ACA titre was a non-significant factor (p = 0.336). The presence of hepatitis C had a higher percentage in group with raised IgG-ACA titres of HD patients (p = 0.042). In predicting for more or one episode of VAT by using multiple logistic regression with all significant factors, the presence of hepatitis C was also a significant factor (p = 0.022). In conclusion, the prevalence of raised IgG-ACA titres was 21.7% among HD patients. There was a weak association between raised IgG-ACA titre and recurrent VAT and this finding may be the consequence of pathogenetic role of raised IgG-ACA titres in the development of VAT status for chronic HD patients. The presence of hepatitis C was a cofactor.

Antibodies, Anticardiolipin↗
PubMed2005

Six novel NPC1 mutations in Chinese patients with Niemann-Pick disease type C.

In patients with Niemann-Pick disease type C (NPC), an autosomal recessive lipid storage disorder, neurodegeneration can occur in early life. Vertical ophthalmoplegia and extrapyramidal signs may be seen. Cholestatic jaundice and hepatosplenomegaly occur frequently in patients with early onset disease, with bone marrow biopsies showing diffuse infiltration of foamy histiocytes. Cholesterol esterification in skin fibroblasts is reduced, resulting in intracellular accumulation of cholesterol. NPC1 mutations are responsible for the disease in approximately 95% of patients. NPC1 encodes a 1278 amino acid protein which contains 13 transmembrane domains. Over 130 mutations have been identified in NPC1, with over a third present within an NPC1 specific cysteine-rich domain positioned in a large extracellular loop. It has been proposed that the defect in cholesterol homoeostasis is the cause of neuronal apoptosis, but the precise role of the NPC1 protein and the functional implications of its mutations remain unknown. Although NPC is routinely diagnosed by biochemical analysis, identification of molecular defects helps confirm the diagnosis and enables family studies, and rapid, accurate prenatal diagnosis. This report describe the analysis of the NPC1 gene in five Taiwanese/Chinese patients with NPC. Six novel NPC1 mutations (N968S, G1015V, G1034R, V1212L, S738Stop, and I635fs) were identified of which three are missense mutations located in the cysteine-rich domain. These are the first NPC1 mutations reported from Chinese patients with NPC.

Adult↗
PubMed2004

Depigmented extramammary Paget's disease.

BACKGROUND: Depigmented extramammary Paget's disease (EMPD) has been reported in a few cases. Depigmented macules or patches may be the only presenting sign or may coexist with the classical erythematous lesions. OBJECTIVES: To investigate the occurrence rate and clinical presentation of depigmentation in EMPD. METHODS: All pathology-proven cases of EMPD diagnosed in our department during 1990-2003 were retrieved. The clinical photographs were reviewed for evidence of local depigmentation. The pathological diagnosis of EMPD in the whitish lesions was confirmed by positive expression of cytokeratin 7 or carcinoembryonic antigen, and/or the presence of intracytoplasmic mucin. RESULTS: Of 19 cases of EMPD, six (30%) manifested depigmented lesions which were confirmed to be EMPD pathologically. In two patients, the hypopigmentation was associated with erythematous lesions at the initial presentation. In four others, the depigmentation developed later as local recurrence after excision, cryotherapy, photodynamic therapy or radiotherapy. The progressive enlargement of the depigmentation and the appearance of separate new white lesions in these four cases suggested that the localized depigmentation was unlikely to be simple postinflammatory hypopigmentation. CONCLUSIONS: Our study suggests that depigmented EMPD may not be rare. Localized depigmentation in the genital area can be an early sign of EMPD and its local recurrence. In patients with an established diagnosis of EMPD, appearance of new white lesions and continuous enlargement of depigmented patches should not be dismissed as simple treatment-induced postinflammatory hypopigmentation or another type of hypopigmented lesion without biopsy confirmation.

Aged↗
PubMed2003

Two novel mutations in the alpha-galactosidase A gene in Chinese patients with Fabry disease.

Fabry disease is an X-linked disorder caused by a deficiency of the lysosomal alpha-galactosidase A [EC 3.2.1.22]. The molecular diagnosis of Fabry disease is important for genotype/phenotype correlation, pre-natal or early diagnosis, and detection of carrier status. Although more than 200 genotypes of the alpha-galactosidase A gene have been identified, mutation data on the Chinese population is sparse. We recently identified two unrelated Chinese families with Fabry disease. Mutation analysis was performed by polymerase chain reaction (PCR) sequencing of the seven exons and adjacent introns of the alpha-galactosidase A gene. Two novel mutations were identified: in family I, a C-to-A transversion resulted in an early termination at amino acid 222 (Y222X), while in family II, an A-to-G transition resulted in a substitution of alanine for threonine at amino acid 410 (T410A). Carrier status was identified in all four females in the two families. The genotype Y222X is associated with classic Fabry disease, with unexpectedly rapid deterioration of visual acuity, while T410A is associated with a milder Fabry disease, with ventricular hypertrophy and neuropathic pain.

Adolescent↗