Biomedical subjects

J H Chen

Publications and source records attributed to J H Chen.

At least 73 records · Page 4Linked to original sources

PubMed2001

Minimal change nephrotic syndrome in children with intrauterine growth retardation.

It has been well established that intrauterine growth retardation (IUGR) is associated with greater morbidity and mortality rates during perinatal and adult life. The aim of this study is to clarify whether IUGR, defined as a birth weight less than the 10th percentile for gestational age, influences the clinical course of minimal change nephrotic syndrome (MCNS) in children. The study included 50 children aged 1 to 13 years at the onset of MCNS. The diagnosis of MCNS was confirmed by renal biopsy in 25 children (50%). Eight children (16%) had IUGR at birth. Comparisons between children with and without IUGR showed significant differences in mean number of relapses (13.0 +/- 3.5 versus 3.4 +/- 3.0 relapses; P < 0.0001) and relapse rates (relapses per year, 1.6 +/- 0.3 versus 0.5 +/- 0.4; P < 0.0001). We also observed a greater incidence of steroid dependence (100% versus 21.4%; P < 0.001) in children with than without IUGR. In addition, children with IUGR underwent treatment with cytotoxic agents and cyclosporine more frequently than those without IUGR. There was a significantly greater incidence of complications and concomitant diseases of nephrotic syndrome in children with IUGR; results show that MCNS in children with IUGR had a more unfavorable course and outcome. It is important for clinicians to be aware that IUGR may help in the early identification of children at greater risk for frequent relapses and the development of steroid dependence and/or steroid resistance. More aggressive therapy may be indicated for these children.

Administration, Oral↗

PubMed2001

Review of telemedicine projects in Taiwan.

Taiwan is a heavily populated country, with a small land area and many mountains and isolated islands. Because medical resources are unequally distributed, high quality accessible medical care is a major problem in rural areas. Medical personnel are unwilling to practice in rural areas because of fear of isolation from peers and lack of continuing medical education (CME) in those areas. Telemedicine provides a timeless and spaceless measure for teleconsultation and education. The development of telemedicine in Taiwan began under the National Information Infrastructure (NII) Project. Distance education and teleconsultation were the first experimental projects during the initiation research stage. The cost and effectiveness of the hardware and network bandwidth were evaluated. In the promotion research stage, applications in different medical disciplines were tested to promote multipoint videoconference, electronic journals and VOD. Investigation of user satisfaction put on more emphasis on improving application functions. In 1998, a new Cyber Medical Center (CMC) international collaboration project was begun, integrating technologies of multimedia, networking, database management, and the World Wide Web. The aim of the CMC is to create a multimedia network system for the management of electronic patient records, teleconsultation, online continuing medical education, and information services on the web. A Taiwan mirror site of Virtual Hospital and two international telemedicine trials through Next Generation Internet (NGI) were done at the end of 1998. In the future, telemedicine systems in Taiwan are expected to combine the Internet and broadband CATV, ADSL, and DBS networking to connect clinics, hospitals, insurance organizations, and public health administrations; and, finally, to extend to every household.

Databases, Factual↗

PubMed2001

Increased nitric oxide production in nasal epithelial cells from allergic patients--RT-PCR analysis and direct imaging by a fluorescence indicator: DAF-2 DA.

BACKGROUND: Nitric oxide (NO) is believed to participate in the regulation of airway clearance and non-specific cellular immunity. Recent studies have suggested that airway epithelial cells of allergic and non-allergic individuals may differ in their ability to produce this molecule. OBJECTIVE: The aim of this study was to detect the difference in NO production in human nasal epithelial cells between normal subjects and patients with perennial allergic rhinitis (AR), and to assess the relationship between the expression of nitric oxide synthase (NOS) isoforms and the severity of the disease. METHODS: Nasal epithelial cells were obtained from the inferior turbinate. The expression of mRNAs encoding constitutive endothelial NOS (eNOS) and inducible NOS (iNOS) was studied by reverse transcription-polymerase chain reaction (RT-PCR). Direct NO production in living cells was visualized and quantified by a fluorescent indicator, DAF-2 DA. RESULTS: RT-PCR analysis demonstrated that AR patients with a RAST score of 5 or 6 showed significant increases in the levels of iNOS mRNA and slight reductions in those of eNOS mRNA. Patients with a RAST score of 2-4 also revealed the same tendency however, the difference was not significant. DAF-2 DA imaging demonstrated that epithelial cells, especially the ciliated cells, produced a larger amount of NO than non-epithelial inflammatory cells. Preincubation with L-NAME resulted in an approximate 40% decrease in both groups. CONCLUSION: These results directly indicate that nasal epithelial cells of AR patients overall produce higher levels of NO through the concomitant expression of different NOS isoforms. Continuous NO production by the epithelial cells in normal subjects further support the hypothesis that NO derived from epithelium may play dual roles in the regulation of nasal airway clearance and in the host defense. In addition, the use of DAF-2 DA provides a reliable method to visualize and quantify the direct NO production of living cells.

Actins↗

PubMed2001

Nonsteroidal anti-inflammatory drugs for treatment of advanced gastric cancer: cyclooxygenase-2 is involved in hepatocyte growth factor mediated tumor development and progression.

Surgical treatment of gastric cancer patients is dismal because advanced tumor is often noted at diagnosis. In order to obtain better adjuvant therapy for gastric cancer patients after operation, it is important to understand the mechanism of invasion and metastasis. It is well known that binding of hepatocyte growth factor (HGF) to its receptor (c-Met) regulates gastric cancer progression and metastasis. Recently, HGF was found to up-regulate the expression of cyclooxygenase-2 (COX-2) gene and increase prostaglandin (PG)synthesis in gastric mucosa cells. Over-expression of COX-2 and increased PG secretion have also been found to be involved in the growth and metastasis of gastric cancer. These results together suggest that the signaling pathway of HGF and c-Met may be mediated through ERK2 activation, up-regulation of COX-2 and increased production of PGE(2)in gastric cancer cells. In view of the fact that c-Met is over-expressed in the majority of gastric cancer patients with poor prognosis, COX-2 specific inhibitors may provide beneficial effects in these patients.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2001

Cytotoxic neolignans and butanolides from Machilus obovatifolia.

From the chloroform-soluble portion of the stem wood of Machilus obovatifolia, one new neolignan, perseal F (1), four known neolignans, perseal G (2), licarin A, licarin B, acuminatin, two butanolides, linderanolide E and isolinderanolide E, two steroids, beta-sitosterol, beta-sitosterol-beta-D-glucoside, and syringaldehyde were isolated. Perseal F (1) and G (2) are neolignans that have a C-1' formyl side chain instead of a propenyl group. Compound 2 was isolated in a mixture with acuminatin. The structure of 2 was identified by comparison with the product formed by the Lemieux-von Rudloff oxidation of licarin B. Two minor oxidative by-products, 2a and 2b, were also obtained. Linderanolide E showed cytotoxicities against P-388, KB16, A549 and HT-29, 1 against P-388, KB16 and HT-29, and isolinderanolide E against P-388, cancer cell lines, respectively. All structures were identified by means of spectroscopic analyses.

Antineoplastic Agents, Phytogenic↗

PubMed2001

Cytotoxic butanolides from the stem bark of Formosan Lindera communis.

Two new butanolides, lincomolide A (1), lincomolide B (2), along with seven known compounds, isolinderanolide E, sepesteonol, beta-sitosterol, beta-sitosterol-beta-glucoside, tetradecane, nonanoic acid and decanol, were isolated from the chloroform-soluble portion of the stem bark of Lindera communis. Compound 1 showed cytotoxicity against P-388, KB16 and A549, and 2 exhibited cytotoxicity against P-388 cancer cell lines. Moreover, 1 showed marginal activity against HT-29, and 2 against KB16, A549 and HT-29 cancer cell lines. The structures of these compounds were determined by spectral analyses.

4-Butyrolactone↗

PubMed2001

Molecular epidemiology of a Shigella flexneri outbreak in a mountainous township in Taiwan, Republic of China.

An outbreak of shigellosis occurred in a township of Nantou Conuty in central Taiwan from August to October in 1996. The infections extended to two neighboring townships and continued to the end of 1996. Forty cases were confirmed during the period, in contrast to only one confirmed case in Nantou County in 1996 before the outbreak. All of these 41 cases in 1996 were identified as infections with Shigella flexneri serotype 2a. In order to trace the source of the infections, the 41 isolates recovered were analyzed by plasmid profile and pulsed-field gel electrophoresis (PFGE). There was no correlation between the plasmid profile results and the PFGE results, and the latter were used for subtyping of the 41 isolates. Twenty-two isolates (53%) had the same NotI and XbaI PFGE patterns, and 4 isolates (10%) had an additional unstable plasmid band in their NotI patterns but otherwise had the same NotI and XbaI patterns as the 22 isolates. These 26 isolates were designated the outbreak strain, and of these, 24 appeared in eight villages in one township and 2 appeared in a neighboring township. Fourteen of the remaining 15 isolates, including the isolate recovered 7 months before the outbreak, had both NotI and XbaI PFGE patterns closely related to those of the outbreak strain, indicating that Shigella infections were endemic in the area. By tracing the first isolation dates of the outbreak strain in individual villages and the neighboring township, it was found that the strain spread along the major arterial road and its branch road as time passed. Our molecular typing results and epidemiological data demonstrated the endemic nature of the outbreak strain as well as a person-to-person mode of transmission for the widespread infections the strain caused.

Adolescent↗

PubMed2001

Salicylates inhibit flavivirus replication independently of blocking nuclear factor kappa B activation.

Flaviviruses comprise a positive-sense RNA genome that replicates exclusively in the cytoplasm of infected cells. Whether flaviviruses require an activated nuclear factor(s) to complete their life cycle and trigger apoptosis in infected cells remains elusive. Flavivirus infections quickly activate nuclear factor kappa B (NF-kappaB), and salicylates have been shown to inhibit NF-kappaB activation. In this study, we investigated whether salicylates suppress flavivirus replication and virus-induced apoptosis in cultured cells. In a dose-dependent inhibition, we found salicylates within a range of 1 to 5 mM not only restricted flavivirus replication but also abrogated flavivirus-triggered apoptosis. However, flavivirus replication was not affected by a specific NF-kappaB peptide inhibitor, SN50, and a proteosome inhibitor, lactacystin. Flaviviruses also replicated and triggered apoptosis in cells stably expressing IkappaBalpha-DeltaN, a dominant-negative mutant that antagonizes NF-kappaB activation, as readily as in wild-type BHK-21 cells, suggesting that NF-kappaB activation is not essential for either flavivirus replication or flavivirus-induced apoptosis. Salicylates still diminished flavivirus replication and blocked apoptosis in the same IkappaBalpha-DeltaN cells. This inhibition of flaviviruses by salicylates could be partially reversed by a specific p38 mitogen-activated protein (MAP) kinase inhibitor, SB203580. Together, these results show that the mechanism by which salicylates suppress flavivirus infection may involve p38 MAP kinase activity but is independent of blocking the NF-kappaB pathway.

Animals↗

PubMed2001

Coexistence of tuberculous constrictive pericarditis and right atrial tuberculoma: a case report.

Tuberculous constrictive pericarditis is a rare condition with a high mortality rate. The coexistence of constrictive pericarditis and intracardiac tuberculoma has not previously been reported. We report the case of a 65-year-old man presenting with left-side pleural effusion and signs of systemic venous congestion for 2 months. Echocardiography and computerized tomography showed a thickened pericardium and a mass in the right atrium. Pericardiectomy and excision of the right atrial mass were performed. Pathologic examination of the pericardium and the right atrial mass both revealed chronic granulomatous inflammation with acid-fast bacilli and confirmed the diagnosis of tuberculous constrictive pericarditis and right atrial tuberculoma. This case reminds us of the possibility of this type of rare combination of tuberculous constrictive pericarditis and intracardiac right atrial tuberculoma, and the need for complete imaging studies when such cases are encountered.

Aged↗

PubMed2001

The relationship of penile rigidity and intracavernous vascular resistance in potent men during intracavernous pharmacological testing.

PURPOSE: We studied the relationship of penile rigidity and intracavernous vascular resistance in potent men during intracavernous pharmacological testing. MATERIALS AND METHODS: Enrolled in our study were 19 potent men undergoing intracavernous pharmacological testing for various reasons. Hemodynamic changes in response to the intracavernous injection of 20 microg. prostaglandin E1 were assessed by color Doppler sonography with simultaneous RigiScan (Dacomed Corp., Minneapolis, Minnesota) monitoring of penile rigidity. The relationship of penile rigidity and intracavernous vascular resistance was determined by correlating hemodynamic data with recorded penile rigidity values. RESULTS: Maximal mean rigidity plus or minus standard deviation of the penile tip and base after intracavernous injection of prostaglandin E1 was 76.8% +/- 8.5% and 97.3% +/- 4.7%, respectively. Penile tip and base rigidity correlated positively with the resistive index (r = 0.69 and 0.75, p <0.0001) and negatively with end diastolic velocity (r = -0.62 and -0.70, respectively, p <0.0001). The formula, rigidity = -128 + 195 x resistive index, was derived to describe the linear regression of penile base rigidity and the resistive index. The formula, rigidity = 59.8 - 3.3 x end diastolic velocity, was derived to describe the linear regression of penile base rigidity and end diastolic velocity. CONCLUSIONS: Penile rigidity correlated strongly with intracavernous vascular resistance in potent men during intracavernous pharmacological testing. The resistive index and end diastolic velocity of the cavernous arteries may each be used to estimate penile rigidity quantitatively.

Adult↗

PubMed2001

[Effect of simulated weightlessness on the apoptosis of thymus cells in tail-suspended mice].

OBJECTIVE: To investigate the effect of simulated weightlessness on apoptosis of thymus cells in mice. METHOD: Tail-suspended mice were used as an animal model of simulated weightlessness; chromosome breakage was measured by PI staining, and changes of cell membrane were determined by Annexin-V analysis. RESULT: As compared with the control, there was no obvious chromosome breakage; the total number of apoptotic cells and number of early apoptotic cells increased in 1 d suspended group; the number of early apoptotic cells increased significantly and the total number of apoptotic cells increased very significantly in 2d suspended groups. CONCLUSION: These results suggested that simulated weightlessness could promote apoptosis of thymus cells.

Animals↗

PubMed2001

Thrombolysis effect with FIIa from Agkistrodon acutus venom in different thrombosis model.

AIM: A fibrinolytic enzyme from Agkistrodon acutus venom, called FIIa, was tested for thrombolytic activity in animals. METHODS: Carotid thrombosis model in rats and rabbits and middle cerebral artery (MCA) thrombosis model in rats were used. RESULTS: Intravenous administration of FIIa, at a dosage of 0.625 mg/kg, resulted in thrombolysis of carotid thrombi. However, in middle cerebral artery thrombosis, the effective thrombolysis dose was 1.25 mg/kg. When the dosage of FIIa increased, the thrombolytic effect was stronger. Histological examination of kidney, liver, heart, and lung tissue showed no hemorrhage. CONCLUSION: It shows that FIIa from Agkistrodon acutus venom is able to solubilize thrombus in vivo without hemorrhage at an effective dose for thrombolysis.

Agkistrodon↗

PubMed2001

Waveforms of the ductus venosus blood flow in normal human fetuses aged 8-38 weeks.

BACKGROUND: We attempted to establish normal Doppler flow velocity waveform patterns in the human fetal ductus venosus (DV), and also to establish a standardized measurement technique. METHODS: Ductus venosus blood flow was measured in a prospective study involving 545 fetuses aged between 8 and 38 weeks in utero, the mothers of whom received prenatal care in Kaohsiung Chang Gung Memorial Hospital in a 12-month period in 1998-1999. Several DV hemodynamic parameters were assessed, including peak systolic velocity (DVP), peak systolic/diastolic (S/D) ratio, time-averaged velocity (TAMX), maximum velocity during atrial contraction (DVM), pulsatility index (PI), Pourcelot's resistance index (RI), and fetal heartbeat (FHB). RESULTS: Technically acceptable ductus venosus blood flow velocity waveform patterns were collected from 490 of 545 pregnant women (89.9%). The mean +/- SD value for the peak systolic DV velocity during the time period of 8 to 38 weeks in utero was 0.33 +/- 0.11 meters/sec (m/s), the TAMX being 0.24 +/- 0.09 m/s. The maximum velocity during atrial contraction was 0.15 +/- 0.09 m/s, and the peak S/D velocity ratio was 2.5 +/- 1.01. The PI, Pourcelot's RI and fetal heart beat were, 0.67(+/- 0.21), 0.64 (+/- 0.11), and 163.3 (+/- 18.82 bpm), respectively. Significant increases in DVP, TAMX, and DVM with advancing gestational age were established, and decreases in PI, RI, S/D, and FHB with advancing gestational age were also observed. CONCLUSIONS: Further investigation of DV hemodynamics throughout pregnancy may enable a greater understanding of normal placental perfusion, the fetal venous return to the heart and associated cardiac function.

Adolescent↗

PubMed2001

Insulin action and insulin secretion in newly diagnosed type 2 diabetic patients.

To clarify the insulin action and insulin secretion in newly diagnosed type 2 diabetic subjects, we investigated insulin and C-peptide response to an oral glucose tolerance test (OGTT) in 15 newly diagnosed type 2 diabetic patients and 17 healthy subjects. For insulin action, we found fasting hyperinsulinemia (8.4 +/- 0.8 vs. 6.0 +/- 0.5 microIU/ml, p = 0.014), higher insulin resistance by homeostasis model assessment (HOMA) (4.33 +/- 0.2 vs. 1.34 +/- 0.1 microIU/ml.mmol/l, p < 0.001), and lower insulin sensitivity index (ISI) (51.0 +/- 0.7 vs. 104.0 +/- 0.8, p < 0.001) in newly diagnosed diabetic patients compared to normal subjects. For insulin secretion, the increments of AUCI (area under curve of insulin) and AUCC-P (area under curve of C-peptide) (increment of AUCI: 26.1 +/- 1.4 vs. 82.8 +/- 4.5 microIU/ml.hour, p < 0.001; increment of AUCC-P: 3.9 +/- 0.2 vs. 11.4 +/- 0.6 ng/ml.hour, p < 0.001), insulin secretion by HOMA model (20.7 +/- 1.2 vs. 79.1 +/- 3.8 IU/mol, p < 0.001), and ratio of 30 min increment of fasting insulin to glucose during OGTT (1.14 +/- 0.1 vs. 13.1 +/- 0.5 IU/mol, p < 0.001) were significantly lower in the newly diagnosed diabetic patients than normal subjects. In addition, body mass index (BMI) in our type 2 diabetes is relatively lower (24 +/- 0.65 kg/m2) than those in western countries. These findings revealed poor insulin action and decreased insulin secretion in relatively less obese Taiwanese with newly diagnosed type 2 diabetes.

Adult↗

PubMed2001

Resection of triple synchronous tumors--gastric adenocarcinoma, gallbladder adenocarcinoma and stromal tumor of the stomach.

We herein report a rare case of triple synchronous tumors: gastric adenocarcinoma, gallbladder adenocarcinoma and stromal cell tumor of stomach, which were resected in the same operation. A 72-year-old male patient suffered from poor appetite and epigastric pain that radiated to his back for one month. Upper gastrointestinal endoscopy showed a gastric ulcer measuring 1.5 cm at the prepyloric area, which was proven to be adenocarcinoma by biopsy. A second tumor was found in the gallbladder, measuring 3 cm, by ultrasonography. On computed tomography, a third tumor about 2.5 cm in size was recognized posterior to the gastric high body and anterior to the pancreas. Given the presence of three tumors, he underwent a radical subtotal gastrectomy with Billroth-II gastrojejunostomy and simultaneous cholecystectomy. Pathological findings revealed gastric adenocarcinoma, gallbladder adenocarcinoma and stromal cell tumor of the stomach. The postoperative course was smooth.

Adenocarcinoma↗

PubMed2001

[Detection of cytomegalovirus infection in recipients of renal transplantation].

OBJECTIVE: To investigate infection of cytomegalovirus (CMV) in recipients of renal transplantation (RT). METHODS: 167 recipients of RT were screened for the occurrence of CMV infection by using ELISA to test anti-CMV IgG, IgM from serum samples, using immunohistochemistry method to test CMV antigen expression and nest PCR to amplify CMV DNA from blood samples. RESULTS: Of these samples, 165 and 3 came out positive of IgG and IgM with the positive rate being 98.8% and 1.8% respectively. 79 samples resulted in antigen expression (47.3%) with the average antigen index being (3.2, 3.1)/5, 104 WBC. Besides, 85 samples were found to be positive by nest-PCR with the positive rate being 50.9%. CONCLUSIONS: The results indicate that the infection of RT so the detection CMV is common in recipients of RT. So detection of CMV-antibody, CMV antigen and CMV DNA after renal transplantation is very important in early diagnosis of CMV infection.

Adolescent↗

PubMed2000

Production and application of LPA polyclonal antibody.

By using colloidal gold as a hapten carrier, a kind of antibody against lysophosphatidic acid (LPA) was developed and used to successfully detect 500 ng/mL LPA in dot immunogold filtration assay. Such application of the LPA antibody could offer us a way to diagnose ovarian cancer at its early stage.

Antibodies↗

PubMed2000

Regulation of ecdysteroid signalling: molecular cloning, characterization and expression of 3-dehydroecdysone 3 alpha-reductase, a novel eukaryotic member of the short-chain dehydrogenases/reductases superfamily from the cotton leafworm, Spodoptera littoralis.

One route of inactivation of ecdysteroids in insects involves ecdysone oxidase-catalysed conversion into 3-dehydroecdysone (3DE), followed by irreversible reduction by 3DE 3 alpha-reductase to 3-epiecdysone. The 3DE 3 alpha-reductase has been purified and subjected to limited amino acid sequencing. It occurs as two distinct forms, including a probable trimer of subunit molecular mass of approx. 26 kDa. A reverse-transcriptase PCR-based approach has been used to clone the cDNA (1.2 kb) encoding the 26 kDa protein. Northern blotting showed that the mRNA transcript was expressed in Malpighian tubules during the early stage of the last larval instar. Conceptual translation of the 3DE 3 alpha-reductase cDNA and database searching revealed that the enzyme belongs to the short-chain dehydrogenases/reductases superfamily. Furthermore, the enzyme is a novel eukaryotic 3-dehydrosteroid 3 alpha-reductase member of that family, whereas vertebrate 3-dehydrosteroid 3 alpha-reductases belong to the aldo-keto reductase (AKR) superfamily. Enzymically active recombinant 3DE 3 alpha-reductase has been produced using a baculovirus expression system. Surprisingly, we observed no similarity between this 3DE 3 alpha-reductase and a previously reported 3DE 3 beta-reductase, which acts on the same substrate and belongs to the AKR family.

3-Hydroxysteroid Dehydrogenases↗