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C-C Chang

Publications and source records attributed to C-C Chang.

At least 19 recordsLinked to original sources
PubMed2006

Estrogen receptor alpha-351 XbaI*G and -397 PvuII*C-related genotypes and alleles are associated with higher susceptibilities of endometriosis and leiomyoma.

Endometriosis and leiomyoma are both common estrogen-related gynaecological diseases. We aimed to elucidate the association of estrogen receptor alpha (ERalpha)-351 A>G (XbaI) and -397 T>C (PvuII) gene polymorphisms with endometriosis and leiomyoma. Women were divided into three groups: (i) severe endometriosis (n = 112), (ii) leiomyoma (n = 106) and (iii) normal controls (n = 110). Genomic DNA was obtained from peripheral leukocytes. ERalpha-351 A/G XbaI and -397 T/C PvuII polymorphisms were assayed by the method of PCR and restriction fragment length polymorphism (RFLP). Genotypes and allelic frequencies in each group were compared. The genotype/allele frequencies of ERalpha-351 and -397 polymorphisms in endometriosis or leiomyoma groups were different from those of normal controls. ERalpha mutant-related genotypes/alleles (-351G and -397C) presented higher percentages in the endometriosis/leiomyoma population compared with normal controls. Proportions of ERalpha-351 AA/AG/GG genotypes and A/G alleles in each group were (i) 26.8/57.1/16.1 and 55.4/44.6%; (ii) 19.8/52.8/27.4 and 46.2/53.8% and (iii) 33.6/64.6/1.8 and 65.9/34.1%. Proportions of ERalpha-397 TT/TC/CC genotypes and T/C alleles in each group were (i) 24.1/60.7/15.2 and 54.5/45.5%; (ii) 23.6/70.8/5.6 and 59/41% and (iii) 54.5/40/5.5 and 74.5/25.5%. We concluded that ERalpha-351 XbaI*G- and -397 PvuII*C-related genotypes/alleles were correlated with higher susceptibilities of endometriosis or leiomyoma, which might be associated with related pathogeneses.

Adult↗
PubMed2006

Central nervous system graft-versus-host disease: report of two cases and literature review.

Two patients with a plausible diagnosis of central nervous system graft-versus-host disease (CNS-GVHD) are described. Both presented with neurological manifestations 6 and 18 months following allogeneic transplant with hemiparesis, seizure, encephalopathy and magnetic resonance findings of hyperintense white matter lesions on T-2 weighed images. Brain biopsy in one and autopsy in the other revealed profound perivascular lymphocytic infiltrates composed predominantly of T-lymphocytes that were of donor origin. Although an unequivocal diagnosis of CNS-GVHD is difficult to establish, the transplantation community should be aware of this controversial entity.

Adult↗
PubMed2006

Involvement of matrix metalloproteinase-13 in stromal-cell-derived factor 1 alpha-directed invasion of human basal cell carcinoma cells.

Basal cell carcinoma (BCC) is one of the most common skin neoplasms in humans and is usually characterized by local aggressiveness with little metastatic potential, although deep invasion, recurrence, and regional and distant metastases may occur. Here, we studied the mechanism of BCC invasion. We found that human BCC tissues and a BCC cell line had significant expression of CXCR4, which was higher in invasive than non-invasive BCC types. Further, of 19 recurrent tumors among 390 BCCs diagnosed during the past 12 years, 17/19 (89.5%) had high CXCR4 expression. We found that the CXCR4 ligand, stromal-cell-derived factor 1alpha (SDF-1alpha), directed BCC invasion and that this was mediated by time-dependent upregulation of mRNA expression and gelatinase activity of matrix metalloproteinase-13 (MMP-13). The transcriptional regulation of MMP-13 by SDF-1alpha was mediated by phosphorylation of extracellular signal-related kinase 1/2 and activation of the AP-1 component c-Jun. Finally, CXCR4-transfected BCC cells injected into nude mice induced aggressive BCCs that co-expressed CXCR4 and MMP-13. The identification of SDF-1alpha/CXCR4 as an important factor in BCC invasiveness may contribute insight into mechanisms involved in the aggressive potential of human BCC and may improve therapy for invasive BCCs.

Basal Cell Carcinoma↗
PubMed2006

Debulking surgery for advanced thymoma.

AIMS: This study was conducted to evaluate the efficacy of debulking surgery in the treatment of locally advanced but operable malignant thymoma. METHODS: We reviewed 43 cases with incompletely resected stage III and IVa malignant thymoma managed between January 1987 and December 2002. RESULTS: Twenty-two had stage III and 21 had stage IVa disease. Maximal debulking was performed in 15 patients, nine with stage III and six with stage IVa disease. Nine patients also had myasthenia gravis (MG). Using univariate Kaplan-Meier analysis, we found that maximal debulking surgery, RT, and with the presence of MG were associated with better survival. Debulking resulted in a better outcome than non-debulking surgery (mean survival: 106 months vs 57.2 months). After adjustment with multivariate analysis, RT and MG were both associated with better survival. CT did not appear to be beneficial for advanced thymoma. CONCLUSIONS: RT is independently associated with a better outcome in locally advanced thymoma. Debulking surgery apparently allows for a better response to RT.

Adult↗
PubMed2006

Imaging diagnosis of testicular lymphoma.

Testicular lymphoma is a rare clinicopathologic entity that has rapid progression and poor prognosis. This report describes a case of a 62-year-old man who presented with a large testicular tumor and extensive lymphadenopathy along the spermatic cord and gonadal vessels to the renal vein level. Testicular lymphoma was considered, and biopsy confirmed a non-Hodgkin, large, B-cell lymphoma. The distribution of lymphadenopathy differs from that of paraaortic lymph nodes that present as other testicular tumors (seminoma or nonseminoma). The finding may be a useful characteristic for timely diagnosis of testicular lymphoma, although the diagnosis should be suspected in an older patient who presents with a testicular neoplasm and increased lactic dehydrogenase levels but without increased alpha-fetoprotein and human chorionic gonadotropin levels.

Biopsy↗
PubMed2006

Double-blind, randomized, multicentre study of the efficacy and safety of gliclazide-modified release in the treatment of Chinese type 2 diabetic patients.

BACKGROUND AND AIM: Gliclazide-modified release (gliclazide MR) is a new formulation of the sulfonylurea gliclazide designed for once-daily administration. The hydrophilic matrix of hypromellose-based polymer in the new formulation induces a progressive drug release, which parallels the 24-h glycaemic profile in type 2 diabetic patients. The aim of this study was to compare the efficacy and safety of gliclazide MR (once-daily administration) versus gliclazide (twice-daily administration) in Chinese type 2 diabetic patients. MATERIALS AND METHODS: Sixty-three type 2 diabetic Chinese patients who had been on diet control alone or on treatment with metformin or on low dose of sulfonylurea were randomized to either gliclazide MR taken once daily or gliclazide taken twice daily. Dosage of metformin was maintained throughout the study, and the sulfonylurea was stopped. The dose of gliclazide MR was increased at 1-month intervals from 30 mg to 120 mg, while that of gliclazide from 80 mg to 320 mg until metabolic control was achieved [fasting plasma glucose (FPG) < or = 7.7 mmol/l] or the maximum dose reached. Efficacy was mainly evaluated by levels of haemoglobin A1c (HbA1c) and FPG. RESULTS: The mean baseline characteristics of the full analysis set 1 (FAS1) (HbA1c, n = 58) and the FAS2 (FPG, n = 61) were comparable in both groups. The levels of HbA1c decreased similarly in both groups over the treatment period: -1.6 +/- 1.6% (p < 0.001) on gliclazide MR (n = 31) and -1.6 +/- 1.4% (p < 0.001) on gliclazide (n = 27). Decrease in HbA1c was observed irrespective of pre-existing therapy for diabetes: -2.3 +/- 1.5% for patients on diet alone; -0.6 +/- 1.3% for patients switched from sulfonylurea to study drug and -1.4 +/- 0.8% for patients on metformin in combination with study drug. FPG decreased significantly from 177.5 +/- 63.5 to 136.7 +/- 42.2 (p < 0.001, n = 32) on gliclazide MR and not significant from 188.2 +/- 62.6 to 163.7 +/- 67.9 (p = 0.059, n = 29) on gliclazide. Both treatments were very well tolerated with no major hypoglycaemic episodes requiring external assistance; only three patients experienced mild hypoglycaemic episodes. CONCLUSIONS: Once-daily gliclazide MR showed a better trend in improving blood glucose control in comparison with gliclazide in type 2 diabetic Chinese patients irrespective of the pre-existing anti-diabetic treatment. The safety profiles of gliclazide MR and gliclazide were similar with a small number of patients having reported hypoglycaemic episodes. Once-daily dosing with gliclazide MR should improve patient compliance, an important factor in long-term glycaemic control.

Adult↗
PubMed2006

Epigenetic characteristics of cloned and in vitro-fertilized swamp buffalo (Bubalus bubalis) embryos.

Swamp buffalos are becoming endangered due to reproductive inefficiencies. This is of concern because many countries depend heavily on their products. Somatic cell nuclear transfer (SCNT) is a potential strategy for preserving endangered species. To date, SCNT in swamp buffalo has succeeded in the creation of blastocyst embryos. However, development to term of SCNT swamp buffalos is extremely limited, and only 1 live birth has been reported. An abnormal epigenetic mechanism is suspected to be the cause of developmental failure, as is also seen in other species. The DNA methylation and histone acetylation are key players in epigenetic modification and display marked variability during embryonic preimplantation development. Knowledge of epigenetic modifications will aid in solving the developmental problems of SCNT embryos and improving reproductive technology in the swamp buffalo. The objective of this study was to determine the relationship between preimplantation embryonic development and 2 epigenetic patterns, global DNA methylation and histone acetylation, in SCNT and in vitro-fertilized (IVF) swamp buffalo embryos. In addition, we examined the correlations between those 2 mechanisms in the SCNT and IVF swamp buffalo embryos throughout the developmental stages using double immunostaining and quantification of the emission intensities using confocal microscopy. We discovered an aberrant methylation pattern in early preimplantation-stage swamp buffalo SCNT embryos. In addition, greater variability in the DNA methylation levels among nuclei within SCNT embryos was discovered. Hyperacetylation was also observed in SCNT embryos compared with IVF embryos at the 4- and 8-cell stages (P < 0.05). Dynamic changes and interplay between these 2 epigenetic mechanisms could be crucial for embryonic development during the early preimplantation period. The aberrancies uncovered here may contribute to the low efficiency of SCNT.

Animals↗
PubMed2005

The implication of follicular lymphoma patients receiving allogeneic stem cell transplantation from donors carrying t(14;18)-positive cells.

We performed real-time quantitative polymerase chain reaction (RQ-PCR) in peripheral blood (PB) and/or bone marrow (BM) samples collected pre- and post transplant from 23 recipient-donor pairs receiving allogeneic stem cell transplantation (allo-SCT) for follicular lymphoma (FL). Of 23 donors, 11 had a PB and/or BM sample positive for t(14;18) (BCL2/IGH fusion) at low levels (<one t(14;18) cell in 10K total cells). Recipients from donors with (n=11) and those without (n=12) detectable t(14:18) cells were similar in age, sex, and disease status pretransplant. No differences in the incidence of graft-versus-host-disease (GVHD), delayed engraftment, relapse rate, disease-free survival and overall survival were identified between the groups. Two recipients without detectable t(14;18) cells pre-transplant showed detectable t(14;18) cells at 2 and 11 years after receiving grafts from donors with t(14:18) cells. Neither patient developed FL 1.5 and 2 years after the emergence of t(14;18) cells. Although the sample size is relatively small, our findings suggest that individuals carrying t(14;18) cells may not be excluded as donors given the lack of an association of t(14;18) detected in donors with adverse clinical outcome. It may be necessary to screen for the donor's t(14;18) status before using t(14;18) for monitoring minimal residual disease by RQ-PCR to exclude the possibility of confounding donor's t(14;18) clone.

Adult↗
PubMed2004

Methylation and acetylation characteristics of cloned bovine embryos from donor cells treated with 5-aza-2'-deoxycytidine.

Differentiated somatic cells and embryos cloned from somatic cells by nuclear transfer (NT) have higher levels of DNA methylation than gametes and early embryos produced in vivo. Reducing DNA methylation in donor cells before NT by treating them with chemicals such as the DNA methyl-transferase inhibitor (5-aza-2'-deoxycytidine; 5-aza-dC) may improve cloning efficiency of NT embryos by providing donor cells with similar epigenetic characteristics as in vivo embryos. Previously, high levels of this reagent were used to treat donor cells, and decreased development of cloned embryos was observed. In this study, we tested a lower range (0.005 to 0.08 microM) of this drug and used cell cycle distribution changes as an indicator of changes in the characteristics of donor cells. We found that at 0.01 microM 5-aza-dC induced changes in the cycle stage distribution of donor cells, increased the fusion rate of NT embryos, and had no deleterious effect on the percentage of blastocyst development. Levels of 5-aza-dC greater than 0.01 microM significantly decreased embryo development. Embryos cloned from donor cells treated with a low dose of 5-aza-dC had higher levels of DNA methylation than embryos produced by in vitro fertilization, but they also had higher levels of histone acetylation. Although 5-aza-dC at 0.04 microM or higher reduced DNA methylation and histone acetylation levels to those of in vitro-fertilized embryos, development to blastocyst was reduced, suggesting that this concentration of the drug was detrimental. In summary, 5-aza-dC at 0.01 microM altered donor cell characteristics while showing no deleterious effects on embryos cloned from treated cells.

Acetylation↗
PubMed2004

Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q2=0.92 and 1.76 GeV2.

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.

Journal Article↗
PubMed2004

Microscopic origin of the next-generation fractional quantum Hall effect.

Most of the fractions observed to date belong to the sequences nu=n/(2pn+/-1) and nu=1-n/(2pn+/-1), n and p integers, understood as the familiar integral quantum Hall effect of composite fermions. These sequences fail to accommodate, however, many fractions such as nu=4/11 and 5/13, discovered recently in ultrahigh mobility samples at very low temperatures. We show that these "next generation" fractional quantum Hall states are accurately described as the fractional quantum Hall effect of composite fermions.

Journal Article↗
PubMed2004

Evaluation of histogenesis of B-lymphocytes in pediatric EBV-related post-transplant lymphoproliferative disorders.

Post-transplant lymphoproliferative disorders (PTLD) are morphologically/clinically heterogeneous. The main goal of this study was to define the histogenesis of PTLD (B-cell phenotype, EBV-related) in seven pediatric patients after allogeneic T-cell-depleted bone marrow transplantation. Immunohistochemical stains using histogenetic markers, including Bcl-6 (expressed by germinal center (GC) B cells), MUM1/IFR4 (late GC and post GC B cells), and CD138 (post GC B cells), were performed on paraffin-embedded tissue. By morphology, four cases were classified as polymorphic PTLD and three as monomorphic PTLD, according to the WHO classification. By the expression pattern of histogenetic markers, five cases (two polymorphic, three monomorphic PTLD) were of late GC/early post GC B-cell origin expressing only MUM1/IRF4. The remaining two cases (one monomorphic, one polymorphic PTLD) were of post GC B-cell origin expressing MUM1/IRF4 and CD138, but not Bcl-6. Our study indicates that histogenesis of PTLD may be defined by histogenetic markers using immunohistochemistry. The results suggest that most pediatric PTLD are of late GC/early post GC B-cell origin, and a minor group is of post GC B-cell origin. The histogenesis of PTLD appears independent of morphologic appearance. Further studies are warranted to confirm our observation and to evaluate the clinical significance of histogenetic pattern of PTLD.

Adolescent↗
PubMed2004

Biological monitoring of exposures to aluminium, gallium, indium, arsenic, and antimony in optoelectronic industry workers.

The main objective of this study was to investigate aluminum, gallium, indium, arsenic, and antimony exposures on blood and urine levels in the optoelectronic workers. One hundred seventy subjects were enrolled in this cohort study. Whole blood and urine levels were determined by inductively coupled plasma-mass spectrometry. Blood indium and urine gallium and arsenic levels in the 103 workers were significantly higher than that in 67 controls during the follow-up period. In regression models, the significant risk factors of exposure were job title, preventive equipment, Quetelet's index, sex, and education level. The findings of this study suggest that gallium, indium, and arsenic exposure levels may affect their respective levels in blood and urine. The use of clean, preventive equipment is recommended when prioritizing the administration of safety and hygiene in optoelectronics industries.

Adult↗
PubMed2004

Acarologic risk of exposure to Borrelia burgdorferi spirochaetes: long-term evaluations in north-western California, with implications for Lyme borreliosis risk-assessment models.

Over a 5-year period (1997-2001) the population densities of Ixodes pacificus Cooley & Kohls (Acari: Ixodidae) nymphs infected with spirochaetes of Borrelia burgdorferi sensu lato (s.l.) were evaluated in areas of 2000 ha at two localities (CHR, nine sites; HREC, seven sites) 25 km apart in Mendocino County, north-western California. The 5-year median density of infected nymphs was significantly higher at CHR than at HREC (0.51 vs. 0.09 per 100 m(2) and site-specific yearly densities exceeding one infected nymph per 100 m2 were 10-fold more likely to occur at CHR than at HREC. The importance of long-term data in acarologic risk assessment was demonstrated by significantly higher median yearly densities of infected nymphs at CHR from 1997 to 1999, whereas both areas had similar densities during 2000-2001. Overall, the causative agent of Lyme borreliosis in North America, B. burgdorferi Johnson et al. sensu stricto (s.s.) accounted for 76% of 46 genetically characterized B. burgdorferi s.l. infections from I. pacificus nymphs. Tremendous variability in acarologic risk was recorded within both areas: yearly densities of infected nymphs varied 11-97-fold between sites at CHR and 8-30-fold at HREC. Part of this variation could be explained by environmental traits, most notably deer usage. However, correlations between environmental factors and density of infected nymphs (for CHR and HREC combined) did not necessarily apply when these areas were considered separately. Thus, a Lyme borreliosis ecology model developed in one of these areas needs testing in the other area.

Animals↗
PubMed2003

Concurrent presence of both patient and donor t(14;18) in a follicular lymphoma patient after undergoing allogeneic BMT: implications for minimal residual disease detection post-transplant.

We report the case of a t(14:18)(+) follicular lymphoma (FL) patient in long-term clinical remission after undergoing an allogeneic bone marrow transplantation (allo-BMT) from a human leukocyte antigen (HLA)-identical sibling donor who was the normal healthy carrier of a t(14:18)(+) B cell clone. Using real-time quantitative PCR (RQ-PCR) and gel electrophoresis, we document the temporal disappearance of the patient's t(14:18)(+) clone early post-transplant with the concomitant emergence and long-term persistence of the donor's t(14:18)(+) clone in the patient's peripheral blood. This report indicates that the use of PCR-based techniques to measure minimal residual disease in FL patients post-alloBMT should incorporate pretransplant screening of the donor for t(14;18). Furthermore, it suggests that healthy individuals with t(14:18) need not be excluded as donors for FL patients treated with allo-BMT.

Adult↗
PubMed2003

Tumor load in patients with follicular lymphoma post stem cell transplantation may correlate with clinical course.

The purpose of this study was to evaluate if the tumor load, as determined by a real-time quantitative PCR (RQ-PCR) assay, correlated with the clinical course of follicular lymphoma patients after stem cell transplantation (SCT). Cryopreserved bone marrow and/or peripheral blood samples obtained at different time intervals after SCT from 11 patients (seven allogeneic, T-cell depleted/four autologous) were tested for tumor load, as defined by t(14;18) positive cells/total cells, using RQ-PCR. None of the six patients who remained in remission had samples with a tumor load >0.01% after SCT, although fluctuating tumor loads of </=0.01% were observed in three of these patients. In contrast, four of the five patients (three allogeneic/two autologous) with relapsed/progressive disease had increasing tumor loads of >0.01% after SCT (0/6 vs 4/5, P<0.02, Fisher's exact). Our results suggest that RQ-PCR measurable tumor load >0.01% after SCT may correlate with relapsed/progressive disease. Prospective studies with greater numbers of cases are indicated to better determine the critical tumor load that predicts poor outcome after SCT with RQ-PCR.

Adult↗
PubMed2002

Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2).

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).

Journal Article↗
PubMed2002

Evolution of porcine reproductive and respiratory syndrome virus during sequential passages in pigs.

Porcine reproductive and respiratory syndrome (PRRS) viruses are recognized as possessing a high degree of genetic and antigenic variability. Viral diversity has led to questions regarding the association of virus mutation and persistent infection in the host and has raised concerns vis-à-vis protective immunity, the ability of diagnostic assays to detect novel variants, and the possible emergence of virulent strains. The purpose of this study was to describe ongoing changes in PRRS virus during replication in pigs under experimental conditions. Animals were inoculated with a plaque-cloned virus derived from VR-2332, the North American PRRS virus prototype. Three independent lines of in vivo replication were maintained for 367 days by pig-to-pig passage of virus at 60-day intervals. A total of 315 plaque-cloned viruses were recovered from 21 pigs over the 367-day observation period and compared to the original plaque-cloned virus by virus neutralization assay, monoclonal antibody analysis, and sequencing of open reading frames (ORFs) 1b (replicase), 5 (major envelope protein), and 7 (nucleocapsid) of the genome. Variants were detected by day 7 postinoculation, and multiple variants were present concurrently in every pig sampled over the observation period. Sequence analysis showed ORFs 1b and 7 to be highly conserved. In contrast, sequencing of ORF 5 disclosed 48 nucleotide variants which corresponded to 22 amino acid variants. Although no epitopic changes were detected under the conditions of this experiment, PRRS virus was shown to evolve continuously in infected pigs, with different genes of the viral genome undergoing various degrees of change.

Amino Acid Sequence↗