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C C Chang

Publications and source records attributed to C C Chang.

At least 199 records · Page 11Linked to original sources
PubMed1998

Restored gap junctional communication in non-tumorigenic HeLa-normal human fibroblast hybrids.

Gap junctional intercellular communication (GJIC) has been implicated in homeostasis, development, differentiation, wound healing or regeneration and adaptive responses of differentiated cells. The dysfunction of homologous or heterologous GJIC has been associated with the tumorigenic phenotype. Restoration of growth control and the suppression of the tumorigenic phenotype have been previously associated with the up-regulation of GJIC by various anti-tumorigenic chemicals or transfection of connexin genes into tumor cells. To test the hypothesis that 'tumor suppressor' genes may be associated with the up-regulation of GJIC, we tested clones of tumorigenic HeLa, several non-tumorigenic HeLa-normal human fibroblast somatic cell hybrids and a tumorigenic segregant of one of the non-tumorigenic hybrids for GJIC. The parental HeLa cells (D98 AH.2) had no detectable GJIC but expressed detectable connexin 43 transcripts, while the non-tumorigenic HeLa-human fibroblast hybrids, which contained the chromosome 11 from the normal human fibroblast (CGL-1, CGL-2, ESH15 and EHS15c1), expressed ample connexin 43 transcripts and showed proficient GJIC. The tumorigenic segregant (CGL-3) from the non-tumorigenic HeLa-human fibroblast hybrid showed no GJIC or connexin 43. These results show that the presence of GJIC is closely linked to the suppression of the tumorigenic phenotype in the HeLa-human fibroblast hybrid and further suggest that GJIC may be associated with the mechanisms of tumor suppression. The mechanism by which the tumor suppressor gene(s) on the normal chromosome in the HeLa-human fibroblasts induces the up-regulation of connexin 43 is not yet explained.

Base Sequence↗
PubMed1998

Bilateral simultaneous tubal sextuplets: pregnancy after in-vitro fertilization--embryo transfer following salpingectomy.

The presence of a damaged tube has been suggested in recent studies to have a negative effect on in-vitro fertilization (IVF) outcome. Performing bilateral salpingectomy prior to IVF to maximize pregnancy rates may also result in unnecessary surgery. This case is also an example of the occurrence of interstitial pregnancy after salpingectomy. This unusual type of ectopic pregnancy must be kept in mind when evaluating a patient suspected of a possible early abnormal gestation after assisted reproductive technolologies.

Adult↗
PubMed1998

Identification of arg-30 as the essential residue for the enzymatic activity of Taiwan cobra phospholipase A2.

Taiwan cobra (Naja naja atra) phospholipase A2 (PLA2) was inactivated by arginine-specific reagents, phenylglyoxal and 1, 2-cyclohexanedione. Kinetic analyses of the modification reaction revealed that the inactivation of PLA2 followed pseudo-first-order kinetics and the loss of activity was correlated with the incorporation of one molecule of modification reagent per PLA2 molecule. This was confirmed by the results of amino acid composition determination, that showed that a marked decrease in enzymatic activity was associated with the modification of one arginine residue. Tryptic cleavage of the modified protein and microsequencing revealed that Arg-30 was the functionally essential residue. The incorporation of a modifier into the PLA2 did not significantly affect the secondary structure of the enzyme, as revealed by the CD spectrum, and Ca2+-binding of the modified PLA2 was unaffected. Nevertheless, the nonpolarity of the active site of PLA2 markedly decreased with the arginine modification, as evidenced by the decreases in the enhancement of Trp and 8-anilinonaphthalene sulfonate fluorescence. These results, together with those of X-ray crystallographic analysis of N. naja atra PLA2 [Scott et al. (1990) Science 250, 1541-1546], demonstrate that Arg-30 is one of the residues involved in the interfacial binding of a PLA2 molecule with its substrate.

Animals↗
PubMed1998

Cysteine contributions to metal binding preference for Zn/Cd in the beta-domain of metallothionein.

Previous studies showed that metals in the beta-domain of metallothionein (MT) are more readily exchangeable and the level of avidity is site specific. This is reflected by energy differences computed with a series of simulated structures derived from X-ray crystallography. In this study, we examined further the contribution of each of the nine cysteines in the beta-domain. By semi-empirical MNDO calculations, we observed that the relative average binding strength is the strongest for Cys21 to Cd[M4] and for Cys26 to Zn[M3], except for the bridging cysteines. These results suggest that binding site preference for Zn/Cd is determined by binding strength between specific cysteines and metal ion species.

Cadmium↗
PubMed1998

Evaluation of intrinsic modulation of synaptic transmission by ATP in mouse fast twitch muscle.

This study aims to evaluate whether endogenous ATP or adenosine modulates the neurotransmission and contractile function of mouse phrenic nerve-diaphragm. Bath application of ATP (1 mM) and alpha, beta-methylene ATP (m-ATP, 0.1 mM) elevated muscle tones, depressed contractions (approximately 12%), and depolarized muscle membranes (approximately 20 mV). Adenosine (1 mM) or low concentrations of ATP (0.1 mM) had no effect. In a low Ca2+ media, ATP caused prolonged inhibitions of endplate potentials (EPPs), whereas m-ATP augmented EPPs while both agents produced slight effects in normal Tyrode solution. When applied by puff ejection, ATP and m-ATP additionally elicited fast transient suppressions of EPPs in association with inhibitions of high K+-evoked releases of miniature EPPs. Blockades of P2 purinoceptors with suramin antagonized all the effects of ATP and m-ATP except the prolonged inhibitions of EPPs induced by ATP, which were antagonized instead by 8-cyclopentyl-1,3-dipropylxanthine (CPDPX), an A1 adenosine receptor antagonist. Suramin and CPDPX did not change contractions nor alter EPPs evoked by a low- or high-frequency nerve stimulation. The results indicate that exogenously applied ATP and m-ATP, via activations of distinct pre- and postsynaptic purinoceptors, exert inhibitory and facilitatory pharmacological modulations on the mature neuromuscular junction. However, because of intrinsic high efficiency of the synaptic transmission under physiological conditions, endogenously released ATP and its degradation product-adenosine-do not build up to concentrations high enough to alter motor functions.

Acetylcholine↗
PubMed1998

Expression of ACAT-1 protein in human atherosclerotic lesions and cultured human monocytes-macrophages.

The acyl coenzyme A:cholesterol acyltransferase (ACAT) gene was first cloned in 1993 (Chang et al, J Biol Chem. 1993;268:20747-20755; designated ACAT-1). Using affinity-purified antibodies raised against the N-terminal portion of human ACAT-1 protein, we performed immunohistochemical localization studies and showed that the ACAT-1 protein was highly expressed in atherosclerotic lesions of the human aorta. We also performed cell-specific localization studies using double immunostaining and showed that ACAT-1 was predominantly expressed in macrophages but not in smooth muscle cells. We then used a cell culture system in vitro to monitor the ACAT-1 expression in differentiating monocytes-macrophages. The ACAT-1 protein content increased by up to 10-fold when monocytes spontaneously differentiated into macrophages. This increase occurred within the first 2 days of culturing the monocytes and reached a plateau level within 4 days of culturing, indicating that the increase in ACAT-1 protein content is an early event during the monocyte differentiation process. The ACAT-1 protein expressed in the differentiating monocytes-macrophages was shown to be active by enzyme assay in vitro. The high levels of ACAT-1 present in macrophages maintained in culture can explain the high ACAT-1 contents found in atherosclerotic lesions. Our results thus support the idea that ACAT-1 plays an important role in differentiating monocytes and in forming macrophage foam cells during the development of human atherosclerosis.

Adult↗
PubMed1998

The clinical features and prognosis of male lupus in Taiwan.

Our objective was to describe the clinical manifestations, laboratory data, and prognosis in male Chinese lupus patients in Taiwan. Seventy-two male lupus patients, diagnosed and followed in Tri-Service General Hospital between 1983 and 1996, were studied and their clinical data analyzed, retrospectively. The mean age at diagnosis was 34+/-16 y (mean+/-s.d., range: 13-82 y). The peak incidence of age at diagnosis was between 13 and 40 years. The three most frequent clinical manifestations were renal disease, 75%; malar rash, 61%; and arthritis, 53%. The three most frequent abnormal laboratory findings were anti-nuclear antibodies (ANA), 97%; hypocomplementemia, 76%; and anti-ds DNA, 57%. The 1-, 5-, and 10-year survival rates were 85%, 76%, and 75%, respectively. In summary, a higher frequency of renal disease, malar rash and photosensitivity, but a lower frequency of arthritis and lymphadenopathy were demonstrated in our 72 ethnic Chinese male Taiwanese lupus patients compared to previous reports of Caucasians. The prognosis seems to be similar to that of both Chinese and Caucasian males but seems to be poor when compared to either Chinese or Caucasian female lupus patients.

Adolescent↗
PubMed1998

Autoantibodies to thyroid peroxidase in patients with type 1 diabetes in Taiwan.

OBJECTIVE: Type 1 diabetes mellitus is frequently associated with autoimmune thyroid disease (ATD). Genetic susceptibility to autoantibody formation in association with ATD and type 1 diabetes mellitus has been described with varying frequencies, but there is still debate about the situation in the Chinese population. We have, therefore, investigated the prevalence of anti-thyroid peroxidase (anti-TPO) in type 1 diabetic patients, and compared the effect of anti-glutamate decarboxylase (anti-GAD) on the thyroid autoimmunity in patients with type 1 diabetes mellitus in Taiwan. SUBJECTS AND METHODS: Two hundred and forty-three subjects with type 1 diabetes mellitus and seventy unrelated normal controls were recruited for the detection of anti-TPO. Two hundred and seventeen sera from two hundred and forty-three type 1 diabetic patients were tested for anti-GAD. RIA and immunoprecipitation were used for anti-TPO and anti-GAD detection respectively. RESULTS: The intra-assay and interassay coefficients of variation of anti-TPO detected by the RIA method ranged from 5.5% to 11.1%. Among 243 type 1 diabetic patients, 53 (21.8%) were positive for anti-TPO. Compared with those without thyroid autoimmunity, there was a female preponderance for the type 1 diabetic patients with thyroid autoimmunity (female:male, 99:91 vs 37:16 respectively). Among the type 1 diabetic patients with thyroid autoimmunity, anti-TPO tended to occur in those of older age or with long-standing disease. The frequency of anti-GAD was 45.6%, (99 of 217), without gender preponderance (males:females, 18.0% vs 27.61%). Compared with those with negative anti-GAD, no significant difference of anti-TPO positivity for the type 1 diabetic patients with positive anti-GAD was found. CONCLUSION: Our data indicated that the RIA method for anti-TPO detection is sensitive and precise for routine clinical use. The presence of anti-TPO in 21.8% of our type 1 diabetic patients confirmed the strong association of ATD and type 1 diabetes mellitus without ethnic differences. The absence of correlation between anti-TPO and anti-GAD in our type 1 diabetic patients suggested genetic heterogeneity in the role of autoimmunity of type 1 diabetes mellitus and ATD among races.

Adolescent↗
PubMed1998

Interaction between high glucose and TGF-beta in cell cycle protein regulations in MDCK cells.

Transforming growth factor-beta (TGF-beta) may mediate high glucose effects in renal cells. Thus, Madin-Darby canine kidney cells were studied for the modulation of cell cycle regulatory proteins by high glucose (27.5 mM) and TGF-beta1. We showed that unlike other renal cells, TGF-beta1 mRNA and its bioactivity were not induced by high-glucose culture. Furthermore, high glucose per se increased cellular proliferation without alterations in cell size. High glucose also increased the percentage of cells in the G2/M phase while decreasing cells in the G0/G1 phase of the cell cycle. In contrast, TGF-beta1 dose dependently (1 to 4 ng/ml) decreased cellular mitogenesis while increasing hypertrophy in the cells, especially in the presence of high glucose. TGF-beta1 also increased the percentage of cells arrested in the G0/G1 phase while decreasing cells in the G2/M phase of the cell cycle. Regarding two of the cell cycle regulatory proteins, high glucose increased cdc2 kinase activity and retinoblastoma protein (pRb) phosphorylation. In contrast, TGF-beta1 decreased cdc2 kinase activity and pRb phosphorylation, especially in the presence of high glucose. Additionally, glucose dose dependently (5.5, 16.5, 27.5, and 38.5 mM) increased type I and II TGF-beta receptor protein expression. In conclusion, changes in cdc2 kinase activity and pRb phosphorylation were correlated with high glucose and TGF-beta1-induced growth effects in a cell cycle-dependent manner in the Madin-Darby canine kidney cells. Furthermore, high glucose may potentiate TGF-beta1-induced effects by enhancing TGF-beta receptor protein expression.

Animals↗
PubMed1998

Induction of apoptosis and down-regulation of bcl-6 in mutu I cells treated with ethanolic extracts of the Chinese herbal supplement PC-SPES.

PC-SPES, an HPLC-standardized 8-herb dietary supplement prepared by proprietary extraction/mixing technologies, appears to have a number of health benefits when given to cancer patients. These include reduction of serum PSA (prostate specific antigen) in individuals diagnosed with advanced prostate carcinoma, and overall improvement of morbidity and immune status in terminal cancer cases. Since the expression of bcl-6 in T and B lymphocytes has been reported to be significantly down regulated by mitogens, we reason that the immune boosting effects of PC-SPES could involve the modulation of bcl-6 expression. Such a hypothesis was tested in the bcl-6 abundant Mutu I cells. Specifically, we investigated the effects of PC-SPES in regulating cell growth, induction of apoptosis, effecting changes in the retinoblastoma gene RB and the modulation of expression of the bcl-6. Herein we report that proliferation of Mutu I cells was inhibited by a 3-7 day incubation with ethanolic extracts of PC-SPES, with concurrent induction of apoptosis. In addition, a dose-dependent reduction of bcl-6 was observed, with no concomitant change in either the phosphorylated or the unphosphorylated forms of RB. These data raise the possibility that PC-SPES may enhance immune functions in vivo by down-regulating bcl-6 expression. Alternatively, decrease in bcl-6 could serve as a biomarker for testing the efficaciousness of PC-SPES in vivo.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Acute pancreatitis in pregnancy.

BACKGROUND: Acute pancreatitis in pregnancy is rare. Our purpose in this study was to discuss the etiology, incidence and course of pancreatitis in pregnancy and to evaluate the maternal and perinatal outcomes. METHODS: Pregnant women with pancreatitis admitted to China Medical College Hospital, Taiwan, from 1980 to 1995 were studied retrospectively. A total of 16 patients were enrolled in the study. Two patients had gallstones and hyperlipidemia; four had gallstones alone; seven had hyperlipidemia alone; one had gestational diabetes mellitus; one had hyperparathyroidism and pregnancy-induced hypertension alone; and one had Hashimoto's thyroiditis. Conservative treatment and low-fat diets were administered to the patients. RESULTS: The incidence of gestational pancreatitis in this series was one in 6,790 pregnancies. The fetal outcome included eight preterm deliveries and three fetal losses. There were no maternal mortalities. The etiologies of pancreatitis were primary hyperlipidemia (56.3%) and gallstones (37.5%). All patients responded favorably to supportive therapy, and most of the symptoms subsided after delivery. CONCLUSIONS: Early diagnosis and treatment is of utmost importance in the management of acute pancreatitis in pregnancy. The results of this study showed good maternal outcome following appropriate treatment. Fetal prognosis was less favorable and was most often associated with hyperlipidemia. Fetal monitoring is essential during the management of pancreatitis in pregnancy.

Acute Disease↗
PubMed1998

Involvement of tyrosine phosphorylation of p185(c-erbB2/neu) in tumorigenicity induced by X-rays and the neu oncogene in human breast epithelial cells.

Ionizing radiation is the exogenous agent best proven to induce breast cancer. c-erbB2/neu amplification and overexpression are known to occur in breast cancer and are correlated with aggressive tumor growth and poor prognosis. We have developed simian virus 40-immortalized cell lines from normal human breast epithelial cells (HBECs) with luminal and stem-cell characteristics. In this study, we examined whether x-rays and a mutated neu oncogene are capable of inducing tumorigenicity in these cells. The results indicated that x-rays were effective in converting immortal non-tumorigenic HBECs to weakly tumorigenic cells that then could be transformed to highly tumorigenic cells by the neu oncogene. The in vitro growth of these tumorigenic cells was significantly faster than that of the parental non-tumorigenic cells in growth factor- and hormone-supplemented or -depleted media. The neu oncogene, however, had no tumorigenic effect on immortal non-tumorigenic cells. The expression of p185(c-erb82/neu) was elevated in neu-transduced immortal or weakly tumorigenic cell lines. However, only in the latter was p185(c-erbB2/neu) found to be phosphorylated at tyrosine residues. Thus, x-rays appear to induce a genetic alteration that confers weak tumorigenicity on immortal HBECs and interacts with p185(c-erbB2/neu) directly or indirectly to give rise to fast-growing tumors.

Animals↗
PubMed1998

Intramural pregnancy with negative maternal serum beta-hCG. A case report.

BACKGROUND: Intramural pregnancy is the rarest form of ectopic pregnancy. The diagnosis depends upon the sonographic finding of intramural gestational sac-like growth and persistent high beta-human chorionic gonadotropin (beta-hCG) levels after dilatation and curettage. No authors mentioned negative beta-hCG result in such situation. Rarely has the literature contained preoperative sonograms and photographs of postoperative gestational tissue. CASE: A 31-year-old woman presented with vaginal spotting for five months. Six months earlier she underwent dilatation and curettage for blighted ovum at 8 weeks' gestation. Since then, incidental vaginal spotting was noted. Sonography demonstrated an intramural cyst with fetal pole-like growth. Serum beta-hCG, diagnostic dilatation and curettage, and hysteroscopic examination were negative. Laparotomy for excision of the cyst confirmed an intramural pregnancy. CONCLUSION: Because of the long period after fetal wastage, negative serum beta-hCG was noted in this case. Negative serum beta-hCG was unreliable in the exclusion of intramural pregnancy. With the sonographic appearance of intramural gestational sac-like growth, in spite of a negative serum beta-hCG the clinician should be alert to the possibility of intramural pregnancy.

Adult↗
PubMed1998

Evaluation of a proposed panel of cardiac markers for the diagnosis of acute myocardial infarction in patients with atraumatic chest pain.

OBJECTIVE: The purpose of this study was to evaluate retrospectively the efficacy of a proposed panel of three cardiac markers (myoglobin, creatine kinase-MB mass [CK-MB], and cardiac troponin I) in the diagnosis of acute myocardial infarction (AMI) in patients with atraumatic chest pain. DESIGN: A total of 110 patients admitted for the evaluation of atraumatic chest pain were examined. Forty-one of these patients were diagnosed with AMI. RESULTS: Five of the 41 patients with AMI had abnormally elevated myoglobin levels, whereas values of CK-MB and/or cardiac troponin I remained negative. Creatine kinase-MB mass alone had a sensitivity of 92.7%, a specificity of 89.9%, a positive predictive value of 84.4%, and a negative predictive value of 95.0% for the diagnosis of AMI. Cardiac troponin I alone had a sensitivity of 90.2%, a specificity of 95.7%, a positive predictive value of 92.5%, and a negative predictive value of 94.3% for the diagnosis of AMI. Cardiac troponin I is a more specific marker for the diagnosis of AMI than CK-MB, particularly in patients with chronic renal failure who are evaluated for chest pain. The combination of CK-MB and cardiac troponin I increased the sensitivity to 100% and the negative predictive value to 100% and had a specificity of 88.4% and a positive predictive value of 83.7%. The panel was diagnostic for all patients with AMI within 12 hours after admission. CONCLUSIONS: Our preliminary results indicate that this panel is highly effective for evaluation of AMI in patients with atraumatic chest pain. Elevated myoglobin levels were useful in detecting patients at high risk for AMI who initially were not detected with other markers. The combination of CK-MB and cardiac troponin I provided much higher sensitivity and had a much higher negative predictive value for the evaluation of AMI than cardiac troponin I or CK-MB alone. The 100% negative predictive value is particularly important because it indicates that patients with negative CK-MB and cardiac troponin I values 12 hours after admission have a negligible likelihood of AMI.

Aged↗
PubMed1998

Rupture of rudimentary horn pregnancy: a case report.

A rare case of rupture of a noncommunicating rudimentary horn pregnancy is presented. The pregnancy continued to 16-weeks' gestation, when the rudimentary horn ruptured. The patient had signs and symptoms of massive hemoperitoneum. An emergency exploratory laparotomy revealed a ruptured rudimentary horn and an intact amnionic sac. Prompt excision of the rudimentary horn was performed. The relative literature and factors associated with a rudimentary horn pregnancy are reviewed and discussed.

Adult↗
PubMed1998

Laparoscopic radical hysterectomy with low paraaortic, subaortic and pelvic lymphadenectomy. Results of short-term follow-up.

OBJECTIVE: To describe a detailed operative procedure for type III laparoscopic radical hysterectomy with bilateral low paraaortic, subaortic and pelvic lymphadenectomy. STUDY DESIGN: Between January 1992 and December 1995, eight patients with cervical carcinoma IA2 or IB1 underwent laparoscopic radical hysterectomy at China Medical College Hospital, Taichung, Taiwan, R.O.C. The procedure of laparoscopic radical hysterectomy was separated into eight segmental steps. RESULTS: No major complications, including ureteral injury and lymphocyst formation, were noted in any case. Mean hospitalization was 6.5 days. The follow-up period ranged from 16 to 62 months. Only one case recurred, in the lung. CONCLUSION: Laparoscopic radical hysterectomy is a safe procedure. A complete pelvic and paraaortic lymphadenectomy and type III radical hysterectomy can be performed laparoscopically. This approach allows shorter hospitalization and carries less morbidity than the open type. Short-term follow-up (1.3-5.1 years) indicated a favorable prognosis.

Adult↗
PubMed1998

Predisposing factors of life-threatening deep neck infection: logistic regression analysis of 214 cases.

OBJECTIVE: In the era of antibiotics, most deep neck infections can be cured by conservative treatment, but some still result in life-threatening complications. In this study, we discuss whether or not there are predisposing factors of complicated deep neck infection. DESIGN: A retrospective chart review of patients presenting between 1988 and 1996 was conducted. METHOD: Among 214 deep neck infection patients, 18 cases resulted in lethal complications. We used the "dummy" variable with logistic regression as the statistical analysis method. RESULTS: Patients with an underlying disease, neck swelling, and delay time had a positive correlation that was statistically significance (p < .05). Patients who were older, male, with complete blood count/differential count-positive finding and fever had positive correlation, but this was not statistically significant (p > .05). CONCLUSION: Although complicated deep neck infection is a rapidly progressive disease with a high mortality, we can not thoroughly predict the prognosis or avoid it happening completely. But, if we can detect and pay more attention to the high-risk group of patients with use of aggressive therapy, the incidence of complicated deep neck infection may be reduced.

Abscess↗