Biomedical subjects

C F Chang

Publications and source records attributed to C F Chang.

At least 127 records · Page 7Linked to original sources

PubMed1994

Transcription of a human neurotropic virus promoter in glial cells: effect of YB-1 on expression of the JC virus late gene.

We have isolated a partial recombinant cDNA clone from a HeLa expression library which encodes a protein capable of binding to the central region of the human neurotropic JC virus (JCV) enhancer/promoter, termed the B region. Sequence analysis revealed a complete homology of the partial cDNA clone to the N-terminal region, of a previously described DNA-binding protein, termed YB-1. Band shift analyses have indicated that the bacterially produced YB-1 interacts specifically with the double-stranded B oligonucleotide as well as the corresponding single-stranded DNA fragment representing the early promoter sequence. Further analysis indicated that the YB-1 protein binds specifically to the C/T-rich sequence of the B domain, which is located in close proximity to the TATA box within the virus enhancer/promoter. Results from cotransfection experiments demonstrated that the full-length (YB-1) but not the partial cDNA enhances expression of the JCV late (JCVL) promoter in glial cells. Cointroduction into glial cells of a recombinant expressing the YB-1 and JCVL deletion mutants indicated that removal of the C/T-rich sequence of the B domain reduces the level of activation of the virus promoter by YB-1. Further cotransfection experiments revealed that the virus transactivating protein T antigen appears to diminish the ability of YB-1 to activate JCVL gene expression. RNA studies indicated that YB-1 is expressed in several cell types and tissues. Examination of YB-1 RNA from mouse brain at various stages of development revealed high levels of YB-1 RNA at early stages of development and lower levels at all subsequent developmental stages.

Antigens, Viral, Tumor↗

PubMed1994

Clinical evaluation of erythrocytosis in patients with hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignancy in southeast Asia and sub-Saharan Africa. During its clinical course, patients may manifest a variety of paraneoplastic syndromes, including erythrocytosis. However, there are few reports on the clinical and biochemical characteristics of HCC patients who manifest erythrocytosis. The purpose of this study is to evaluate the incidence of erythrocytosis in a large series of the Chinese patients with HCC, and to investigate the association of erythrocytosis with tumor volume and with serum levels of alpha-fetoprotein (AFP) and erythropoietin. METHODS: Among 792 Chinese HCC patients who were seen during a 3-year period, we identified HCC patients with erythrocytosis as those with hemoglobin levels greater than 16.7 gm/dL (two standard deviations above the mean hemoglobin level of matched normal controls). The tumor size and serum levels of AFP and erythropoietin were evaluated in HCC patients with erythrocytosis to compare with HCC patients without erythrocytosis. RESULTS: 20 (2.5%) of 792 Chinese HCC patients presented with erythrocytosis. Nineteen of these 20 HCC patients were found to have either bi-lobar tumor involvement or a large tumor mass confined to one lobe of the liver. The estimated mean tumor volume of HCC patients with erythrocytosis was 50% of whole liver. When compared with HCC patients without erythrocytosis, the 20 HCC patients with high hemoglobin levels had significantly higher serum levels of AFP and erythropoietin (356,343 +/- 145,807 vs. 16,881 +/- 10,425 ng/mL, 135 +/- 45 vs. 25 +/- 4 mU/mL, respectively, p < 0.01). CONCLUSIONS: Base on our findings, detection of erythrocytosis in a patient with HCC would indicate the presence of a large tumor burden, and high serum levels of both AFP and erythropoietin should be associated with this paraneoplastic syndrome.

Carcinoma, Hepatocellular↗

PubMed1994

[How should high concentration oxygen be provided with a resuscitator during resuscitation?].

Oxygen is essential to life. When one is suffering from illness or trauma, the oxygen demand increases because of catabolic response. High concentration oxygen is therefore required in resuscitation. In Taiwan, as well as in other countries, medical personnel usually provide artificial ventilation with a resuscitator. However, the percentage of oxygen delivered from the bag varies significantly in different conditions. To provide high-concentration oxygen during resuscitation, it is necessary to use a resuscitator with an oxygen reservoir and sufficient supplemental oxygen flow.

Humans↗

PubMed1994

Use of esmolol to prevent hemodynamic changes during intubation in general anesthesia.

To assess the minimal effective dosage of esmolol to prevent hypertension and tachycardia during laryngoscopy and endotracheal intubation in fentanyl-pretreated anesthesia, a double-blinded, randomized study was conducted. Two hundred patients undergoing elective, noncardiac surgeries were randomly allocated into four groups: group A received saline, group B esmolol 20 mg, group C esmolol 40 mg and group D esmolol 60 mg intravenously. General anesthesia was induced with 0.1 mg/kg vecuronium, 5 micrograms/kg fentanyl and 0.3 mg/kg etomidate. Heart rates (HR), systolic blood pressures (SBP), mean arterial pressures (MAP) and diastolic blood pressures (DBP) were recorded before induction, after induction, before intubation, 30 seconds, 1 minute, 2 minutes, 4 minutes, 6 minutes, and 10 minutes after intubation. After intubation HR and SBP increased significantly in group A (86.7 beats/min, 166.6 mmHg) in comparison with groups C (77.6 beats/min, 153.9 mmHg) and D (73.4 beats/min, 153.4 mmHg) (p < 0.05). Tachycardia (HR > 100) was found in 13 of 50(26%) patients in group A, 10 of 50(20%) patients in group B, 7 of 50(14%) patients in group C and 2 of 50(4%) patients in group D. Hypertension (SBP > 180) was found in 18(36%) patients in group A, 19(38%) patients in group B, 9(18%) patients in group C, and 6(12%) patients in group D. When compared with group A, only group D had significantly lower incidence of these adverse events (p < 0.05). In conclusion, fentanyl 5 micrograms/kg could not completely prevent the hemodynamic changes associated with endotracheal intubation, and 60 mg esmolol was observed to have positive effect in helping to control these changes.

Adrenergic beta-Antagonists↗

PubMed1994

Serum and ascitic concentration of C3, C4 and protein in cirrhotic patients with spontaneous bacterial peritonitis.

BACKGROUND: Lower concentration of ascitic or serum complement (C3, C4) or protein has been reported to participate in the development of spontaneous bacterial peritonitis (SBP). In Taiwan, the etiology of hepatic cirrhosis is mainly post-hepatic and SBP is the common complication. This study aims to determine the role of protein and complements in the pathogenesis of SBP. METHODS: 119 cirrhotic patients were divided into two groups, 30 SBP and 89 non-SBP. The concentrations of ascitic and serum complement and protein were measured for comparison. RESULTS: The ascitic and serum C3, C4 and protein levels were significantly lower (P < 0.05) in patients with SBP than in non-SBP patients. No significant differences were noted in the ascites/serum ratio of C3, C4 and protein in patient with or without SBP. CONCLUSIONS: Low levels of ascitic and serum protein and complements, C3 and C4, may be prone to develop SBP in our patients mostly with post-hepatitic cirrhosis.

Aged↗

PubMed1994

Risks of bloodborne diseases to emergency personnel in traumatic wound management.

High prevalence of viral hepatitis, increasing HIV infection and other bloodborne diseases in Taiwan have made the health care provider exposed to an increased risk of disease transmission unless adequate precautions and protections have been undertaken. Furthermore, emergency personnel must face the patient with limited information, and neither a reliable predictor nor appropriate tools have been found to assist in identifying emergency patients who pose a risk. The Centers for Disease Control (CDC) in the United States thus issued a specific caveat advocating all body fluids should be treated as potentially infectious under uncontrolled emergency circumstances. Unfortunately, in Taiwan, personnel in emergency service practice with limited protection, often without mask and only gloves as the only barrier device used. We tried to determine the risk of facial exposure during traumatic wound management. One hundred and fifteen wounds of 107 patients were enrolled. Most of them were not life-threatening and thus could be managed under more controlled conditions. Standard procedures of wound management were applied and facial exposure was assessed after each wound closure. Positive exposure rate in such controlled conditions remained as high as 46/115 (40%). Exposure rate in uncontrolled conditions should be, therefore, much more significant. Therefore, we should put more emphasis on adequate precaution and protection against bloodborne diseases.

Blood-Borne Pathogens↗

PubMed1993

How well is debt managed by nonprofits?

Little is known about why nonprofits accrue debt, how much they owe, and whether the funds they borrow are used productively. This article distinguishes between productive, problematic, and deferred debt. Employing a data base representative of 114,726 tax-filing charitable nonprofits in the United States in 1986, it examines the pervasiveness of nonprofit debt and the relation between this debt and nonprofit financial health. The analysis finds that over 70 percent of the nonprofits hold debt, the distribution of this debt is highly concentrated, and the level of debt and leverage varies with asset size and type of activity. Nonprofits with higher leverage and absolute debt levels are financially healthier than those with lower levels. While the analysis does not determine whether financially stronger nonprofits are better able to borrow, the results support the view that borrowing in the nonprofit sector is economically efficient.

Capital Financing↗

PubMed1993

Inhibition of human neurotropic virus (JCV) DNA replication in glial cells by camptothecin.

Progressive multifocal leukoencephalopathy is a subacute demyelinating disease of the central nervous system (CNS) resulting from opportunistic infections in immunocompromised patients infected with a common polyomavirus, JC virus (JCV). Unlike other polyomaviruses, JCV exhibits an unusually narrow tissue tropism by primarily infecting glial cells of the CNS. JCV DNA replication is similar to that of the well-characterized papovavirus, SV40, which requires the viral early protein T-antigen and host-replication factors including DNA polymerases and DNA topoisomerase I. In this study we have been able to effectively block replication of viral DNA in glial cells using camptothecin, a drug which inhibits DNA topoisomerase activity. Pulse-treatment of cells with non-toxic levels of camptothecin specifically blocks viral DNA replication with no inhibitory effect on host transcription and translation processes as examined by viral gene expression in the transfected cells. Furthermore, drug treatment of the cells exhibits no significant effect on DNA topoisomerase I gene transcription. We further demonstrate that repeated pulse-treatment of cells with the drug is required for complete blockage of viral DNA replication. The importance of these findings in the treatment of AIDS encephalopathy is discussed.

Antineoplastic Agents↗

PubMed1993

Hospital characteristics: can an audit be predicted?

Each year Medicare-participant hospitals submit a cost report to the Health Care Financing Administration (HCFA) to settle their reimbursement claims. These reports are subject to audit, and a decision by HCFA to audit can be costly to the auditee. This article uses data from 6,270 cost reports filed in 1986 to explore the factors related to the probability of an audit. Logistic regression equations are estimated to examine how hospital characteristics influence the chance of audit. The results suggest that audit probability can be predicted with reasonable accuracy by a hospital's bed size, ownership type, teaching status, function, proportion of Medicare inpatient days, and geographic location.

Data Collection↗

PubMed1993

Hepatic actinomycosis with portal vein thrombosis mimicking hepatocellular carcinoma: a case report.

A fatal case of hepatic actinomycosis with portal vein thrombosis is reported. The diagnosis of actinomycosis was delayed because of its rarity in Taiwan. This 63-year-old man was admitted due to body weight loss and poor appetite. No fever was noted before admission. Liver biochemical test showed a decreased serum albumin level with elevated serum levels of globulin and alkaline phosphatase. He was not a hepatitis B carrier and his serum level of alfafetoprotein was within normal range. Image studies (abdominal sonography and computed tomography) showed a hepatic mass over the medial segment of the left lobe with involvement of right lobe of the liver. Main portal vein thrombosis was also seen. Because of profound cachexia, he died of aspiration pneumonia and disseminated intravascular coagulation on the 11th day after admission. An autopsy revealed hepatic actinomycosis. High index of suspicion for early diagnosis and treatment is emphasized.

Actinomycosis↗

PubMed1993

Effects of epidural morphine and intramuscular diclofenac combination in postcesarean analgesia: a dose-range study.

To assess the efficacy of combinations of epidural morphine and intramuscular diclofenac in postcesarean analgesia, a double-blind, randomized study was conducted. Epidural anesthesia was administered to 120 parturients who were randomly allocated into six treatment groups; these groups, A, B, C, D, and E, received 0.5, 1, 2, 3, and 4 mg of epidural morphine in 10 mL of normal saline solution, respectively, and 75 mg (3 mL) of diclofenac intramuscularly (IM). Group F received 4 mg of epidural morphine in 10 mL of normal saline solution and 3 mL of normal saline solution IM. Epidural injections were given after delivery of the placenta and IM injections were given on arrival in the recovery room. Verbal analogue pain score and pruritus score were recorded at 2, 4, 8, 12, 18, and 24 h after epidural injection. Subjective scores of overall pain relief also were recorded at 24 h. Results showed that group A had the highest pain scores and required more supplemental meperidine than groups C, D, E, and F. None of the patients in groups D and E requested supplemental analgesia. There were no differences in wound pain score among groups B, C, D, E, and F. Compared with group F, groups D and E experienced a superior analgesic effect in relieving uterine contraction pain from 4 to 12 h (P < 0.05). There were no differences in overall pain relief among the six groups. The incidence of nausea or vomiting or both, pruritus, and bleeding was similar. There was no evident relationship between severity of pruritus and morphine doses. No bradyspnea was observed during the study period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Purification of the sex steroid-binding protein from common carp (Cyprinus carpio) plasma.

1. Sex steroid-binding protein was purified from common carp plasma. 2. Testosterone- and estradiol-binding activity existed at the same fraction eluted from gel Sepharose CL-2B, DEAE-Sephacel, hydroxylapatite and HPLC. 3. The molecular weight of the sex steroid-binding protein was 194,000. 4. At 50% displacement the order in which the steroids displaced [3H]testosterone bound to the binding protein was as follows: androstenedione greater than estradiol-17 beta greater than 11-deoxy-17-hydroxycorticosterone greater than 17 alpha-hydroxyprogesterone greater than progesterone greater than deoxycorticosterone greater than estrone greater than 11-ketotestosterone greater than 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one greater than androstenedione greater than pregnenolone greater than cortisone greater than cortisol.

Animals↗

PubMed1992

A randomized controlled trial comparing octreotide and vasopressin in the control of acute esophageal variceal bleeding.

This randomized controlled trial was conducted to compare the efficacy of intravenous infusion of octreotide (a synthetic long-acting somatostatin analogue) with vasopressin in 48 cirrhotic patients with endoscopically proven bleeding esophageal varices. Twenty-four patients received a continuous infusion of octreotide 25 micrograms/h for 24 h after an initial bolus of 100 micrograms and another 24 patients received a continuous infusion of vasopressin 0.4 U/min for 24 h. Bleeding was initially controlled after 6 h of drug infusion in 88% (21/24) and 54% (13/24) of the patients treated with octreotide and vasopressin respectively (p = 0.03). Complete control of bleeding after 24 h of drug infusion was achieved in 15 (63%) patients receiving octreotide and in 11 (46%) patients receiving vasopressin (p > 0.05). Side effects during drug infusion such as headache, chest pain and abdominal pain were significantly lower in the octreotide group (3/24) than in the vasopressin group (11/24). Serum gastrin and insulin levels fell significantly following octreotide infusion, but plasma glucose levels remained unchanged. Mortality related to bleeding esophageal varices was no different between the two groups. This report showed that octreotide infusion was more effective and had fewer side effects than vasopressin in initial controlling of acute esophageal variceal bleeding until an elective endoscopic sclerotherapy could be performed.

Aged↗

PubMed1992

Evidence that a sequence similar to TAR is important for induction of the JC virus late promoter by human immunodeficiency virus type 1 Tat.

A specific RNA sequence located in the leader of all human immunodeficiency virus type 1 (HIV-1) mRNAs termed the transactivation response element, or TAR, is a primary target for induction of HIV-1 long terminal repeat activity by the HIV-1-derived trans-regulatory protein, Tat. Human neurotropic virus, JC virus (JCV), a causative agent of the degenerative demyelinating disease progressive multifocal leukoencephalopathy, contains sequences in the 5' end of the late RNA species with an extensive homology to HIV-1 TAR. In this study, we examined the possible role of the JCV-derived TAR-homologous sequence in Tat-mediated activation of the JCV late promoter (Tada et al., Proc. Natl. Acad. Sci. USA 87:3479-3483, 1990). Results from site-directed mutagenesis revealed that critical G residues required for the function of HIV-1 TAR that are conserved in the JCV TAR homolog play an important role in Tat activation of the JCV promoter. In addition, in vivo competition studies suggest that shared regulatory components mediate Tat activation of the JCV late and HIV-1 long terminal repeat promoters. Furthermore, we showed that the JCV-derived TAR sequence behaves in the same way as HIV-1 TAR in response to two distinct Tat mutants, one of which that has no ability to bind to HIV-1 TAR and another that lacks transcriptional activity on a responsive promoter. These results suggest that the TAR homolog of the JCV late promoter is responsive to HIV-1 Tat induction and thus may participate in the overall activation of the JCV late promoter mediated by this transactivation.

Base Sequence↗

PubMed1992

Combination of low-dose epidural morphine and intramuscular diclofenac sodium in postcesarean analgesia.

Epidural morphine is used for postcesarean analgesia, and nonsteroidal antiinflammatory drugs are frequently administered to relieve uterine cramps after vaginal delivery. To assess the efficacy of a combination of low-dose epidural morphine and intramuscular diclofenac sodium in postcesarean analgesia, a double-blind, randomized study was conducted. Epidural anesthesia was given to 120 parturients who were randomly allocated into four treatment groups: group A received normal saline solution, 10 mL epidurally and 3 mL intramuscularly (IM); group B received 10 mL of epidural saline solution and 75 mg (3 mL) of diclofenac IM; group C received 2 mg of morphine in 10 mL of epidural saline solution and 3 mL of saline solution IM; and group D received 2 mg of morphine in 10 mL of epidural saline solution and 75 mg of diclofenac IM. Epidural injections were given after delivery of the placenta, and IM injections were given on arrival in the recovery room. Verbal analogue pain scores were recorded at 2, 4, 8, 12, 18, and 24 h after epidural injection. Subjective scores of overall pain relief were also recorded at 24 h. Results showed that scores of overall pain relief were significantly better in group D compared with group A, B, or C (P less than 0.05). Groups A and B required more supplemental meperidine than groups C and D. None of the subjects in group D requested supplemental analgesia. Compared with the other three groups, group D experienced a better analgesic effect for both wound pain and uterine cramping pain from 4 to 18 h (P less than 0.05). Incidence of nausea or vomiting, or both, and pruritus occurred more frequently in groups C and D compared with group A or B (P less than 0.05). No bradypnea was observed during the study period. Diclofenac alone was not effective in postcesarean analgesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Nonprofit equity: a behavioral model and its policy implications.

This article assumes that nonprofit decisionmakers have an incentive to earn and accumulate surpluses, and it suggests six reasons for this being the case. Based on the assumption that both the program outputs and the equity of a nonprofit yield satisfaction to its decisionmakers, a behavioral model is developed. This is used to derive a demand function for equity, which is then applied to a national sample of 6168 charitable nonprofits drawn by the Internal Revenue Service for the 1985 taxable year. The results substantiate the hypothesis that nonprofit decisionmakers consciously plan to increase their organization's equity. Currently, evidence of continued equity buildup is not sufficient to call into question a nonprofit's exempt status, because federal tax laws assume that surplus accumulations will ultimately be used in support of program mission. However, equity accumulation can become excessive. We present several criteria to define excessive equity accumulation and discuss why large equity accumulations may not be in the best interest of society.

Administrative Personnel↗

PubMed1992

Endoscopy for upper gastrointestinal bleeding at emergency unit.

From November 1, 1990 to January 31, 1991, 381 patients visited our emergency unit with the chief complaints of hematemesis (n = 153) and melena (n = 228). Of these patients, 298 (78.2%) received UGI endoscopy at the emergency unit, 29 (7.6%) received examination after they were admitted to wards, 3 (0.8%) received endoscopy at outpatient clinic and 51 (13.4%) did not have endoscopy. The percentages of endoscopic diagnoses in 330 patients who had UGI endoscopy were gastric ulcer (GU) 33.6%, duodenal ulcer (DU) 32.7%, esophageal varices (EV) 17.0%, and others 15.5%. Negative findings were noted in 3 cases and no definite bleeding source was found in 1 patient who had blood retention in stomach. The diagnostic rate of endoscopy was 98.8%. Of the 56 patients with EV, 45 (80.4%) had hematemesis; in contrast, 85 of the 108 DU patients (78.8%) complained of melena only. Of the 219 patients with bleeding GU/DU, 64 (29.2%) had endoscopic therapies and 7 (3.2%) needed operation. Sixty-four (29.2%) of them received UGI endoscopy within 6 hours after arrival. They had significantly higher frequency of stigmata of recent hemorrhage (SRH) and more endoscopic therapies than the remaining patients. The overall mortality rate in our patients was 6.0%; the mortality rate in patients with EV was much higher than that of the patients with GU/DU (19.6% vs. 1.8%, P less than 0.001). Of the 23 expired cases, only 11 died of hypovolemic shock. The remaining 12 patients died of deterioration or complications of their underlying diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Dihydropyridine-sensitive calcium channels from skeletal muscle. II. Functional effects of differential phosphorylation of channel subunits.

Dihydropyridine-sensitive Ca2+ channels from skeletal muscle are multisubunit proteins and are regulated by protein phosphorylation. The purpose of this study was to determine: 1) which subunits are the preferential targets of various protein kinases when the channels are phosphorylated in vitro in their native membrane-bound state and 2) the consequences of these phosphorylations in functional assays. Using as substrates channels present in purified transverse (T) tubule membranes, cAMP-dependent protein kinase (PKA), protein kinase C (PKC), and a multifunctional Ca2+/calmodulin-dependent protein kinase (CaM protein kinase) preferentially phosphorylated the 165-kDa alpha 1 subunit to an extent that was 2-5-fold greater than the 52-kDa beta subunit. A protein kinase endogenous to the skeletal muscle membranes preferentially phosphorylated the beta peptide and showed little activity toward the alpha 1 subunit; however, the extent of phosphorylation was low. Reconstitution of partially purified channels into liposomes was used to determine the functional consequences of phosphorylation by these kinases. Phosphorylation of channels by PKA or PKC resulted in an activation of the channels that was observed as increases in both the rate and extent of Ca2+ influx. However, phosphorylation of channels by either the CaM protein kinase or the endogenous kinase in T-tubule membranes was without effect. Phosphorylation did not affect the sensitivities of the channels toward the dihydropyridines. Taken together, the results demonstrate that the alpha 1 subunit is the preferred substrate of PKA, PKC, and CaM protein kinase when the channels are phosphorylated in the membrane-bound state and that phosphorylation of the channels by PKA and PKC, but not by CaM protein kinase or an endogenous T-tubule membrane protein kinase, results in activation of the dihydropyridine-sensitive Ca2+ channels from skeletal muscle.

Animals↗