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Biomedical subjects

T S Chen

Publications and source records attributed to T S Chen.

At least 37 records · Page 2Linked to original sources
PubMed1999

Variation of capsaicin-sensitive motor activities along the rat gastrointestinal tract.

Variation in motility may be a character to move gut contents. The aim of present study was to assess whether the rat upper gastrointéstinal motilities were variable according to the segments or studied periods under systemic capsaicin treatment. Sedated rats were intubated with a catheter to feed a suspension containing both charcoal and radiochromium motility markers. Capsaicin in the doses of 0.5 mg kg-1, 1 mg kg-1, 5 mg kg-1 or vehicle were simultaneously injected via intraperitoneal route. They were sacrificed at 5 min or 30 min later and the whole gut was removed. Charcoal transit in the small intestine was computed while the radioactivities of stomach and ten equally divided small intestinal segments were counted to obtain the gastric emptying and geometric center of intestinal transit, respectively. Large dose treatment inhibited early gastric emptying (p < 0.05), whereas late gastric emptying remained unchanged. Larger dose treatment inhibited charcoal represented transit in the early (p < 0.05) and late periods (p < 0.01). The intestinal transits seen with geometric center were almost similar to these of charcoal representation (p < 0.01). In conclusion, capsaicin-sensitive gastric emptying changes with studied periods while intestinal transit is always inhibited at any period. We confirm the notion of variation in capsaicin-sensitive motor responses along the rat upper digestive organ.

Animals↗
PubMed1999

Smoking and male gender rather than CagA protein are associated with increased risk for duodenal ulcer in Helicobacter pylori-infected patients in Taiwan.

The aim of this study was to examine the seroprevalence of antibody to CagA antigen, as well as other major H. pylori antigens by Western blot in H. pylori-infected subjects with endoscopically normal mucosa (N = 54) and duodenal ulcer (N = 51). The role of the host and environmental factors was also evaluated. There was no significant difference in the prevalence of antibodies against the major H. pylori antigens between the two groups. A high prevalence of antibody to CagA was detected in patients with normal mucosa (93%) and duodenal ulcer (86%). Multivariate analysis shows that male gender (odds ratio = 4.94, 95% CI = 1.39-17.77, P = 0.014) and smoking (odds ratio = 8.89, 95% CI = 2.17-36.48, P = 0.002) were associated with duodenal ulcer disease. This study suggests that smoking and male gender rather than CagA protein are associated with increased risk for duodenal ulcer in H. pylori-infected patients in Taiwan.

Antibodies, Bacterial↗
PubMed1999

Sequence polymorphism of the group 1 allergen of Bermuda grass pollen.

BACKGROUND: Cyn d 1, the major allergen of Bermuda grass pollen, consists of a number of isoforms. OBJECTIVE: To examine the extent of sequence variation of Cyn d 1 isoforms at the molecular level. METHODS: A Bermuda grass pollen lambdaZAP II cDNA expression library was immunoscreened with anti-Cyn d 1 monoclonal antibodies. The reactive clones were isolated, subcloned into Escherichia coli, and sequenced. Some of them were expressed in the yeast Pichia pastoris to obtain recombinant Cyn d 1 proteins. RESULTS: Ten cDNA clones were obtained, all these clones encode the full length of Cyn d 1 protein. Their deduced mature proteins can be grouped into: the long ones with 246 amino acids, and the short ones with 244 amino acids. The last two amino acids (AG) of the long Cyn d 1 are deleted in the short Cyn d 1. The remaining amino acid sequences share more than 98% identity; a total of nine amino acid variations were observed. Two recombinant Cyn d 1 proteins (rCyn d 3-2 and rCyn d 5-4) with three amino acid substitutions showed differential IgE-binding profiles. CONCLUSION: The present study extended our understanding of the primary structure of isoforms of Cyn d 1.

Allergens↗
PubMed1999

Misoprostol-inhibited rat gastric emptying is independent of gastric inhibitory polypeptide release.

We studied the effects of orally or intraperitoneally administrated misoprostol on rat gastric emptying and looked what was the role of gastric inhibitory polypeptide (GIP) in this emptying. The rats initially received oral misoprostol at doses of 1, 10, 50, and 100 microg/kg. Another group of rats received misoprostol intraperitonally at doses of 10, 50, 250, and 500 microg/kg. Using an oral radiochromium motility marker, the liquid gastric emptying was measurement 30 min after misoprostol treatment. The plasma GIP levels were measured by a home-made radioimmunoassay kit. Oral treatments at the doses of 1 and 10 microg/kg did not influence emptying, whereas other doses delayed emptying (p < 0.01). Except the 10- microg/kg injection, other doses exhibited a dose-dependent inhibition in emptying (p < 0.01). Neither oral feeding nor intraperitoneal injection changed plasma GIP levels. We conclude that liquid gastric emptying is disturbed after various routes of misoprostol treatment; GIP appears less important in the misoprostol-mediated gastric emptying.

Administration, Oral↗
PubMed1999

Increasing dietary cholesterol induces different regulation of classic and alternative bile acid synthesis.

We investigated the effect of increasing dietary cholesterol on bile acid pool sizes and the regulation of the two bile acid synthetic pathways (classic, via cholesterol 7alpha-hydroxylase, and alternative, via sterol 27-hydroxylase) in New Zealand white rabbits fed 3 g cholesterol/per day for up to 15 days. Feeding cholesterol for one day increased hepatic cholesterol 75% and cholesterol 7alpha-hydroxylase activity 1.6 times without significant change of bile acid pool size or sterol 27-hydroxylase activity. After three days of cholesterol feeding, the bile acid pool size increased 83% (P < 0.01), and further feeding produced 10%-20% increments, whereas cholesterol 7alpha-hydroxylase activity declined progressively to 60% below baseline. In contrast, sterol 27-hydroxylase activity rose 58% after three days of cholesterol feeding and remained elevated with continued intake. Bile drainage depleted the bile acid pool and stimulated downregulated cholesterol 7alpha-hydroxylase activity but did not affect sterol 27-hydroxylase activity. Thus, increasing hepatic cholesterol does not directly inhibit cholesterol 7alpha-hydroxylase and initially favors enzyme induction, whereas increased bile acid pool is the most powerful inhibitor of cholesterol 7alpha-hydroxylase. Sterol 27-hydroxylase is insensitive to the bile acid flux but is upregulated by increasing hepatic cholesterol.

Animals↗
PubMed1999

The accomplishments of Sir James Cantlie.

Sir James Cantlie succeeded in his diverse endeavours. A pioneer in first aid medicine in Britain, he wrote several important manuals on the topic. The interlude in Hong Kong set the stage for his role in Chinese history with his involvement with Sun Yat-Sen, the father of modern China, and in the establishment of the present Faculty of Medicine at the University of Hong Kong. The contact with tropical diseases sustained a career that included the founding of the current Royal Society of Tropical Medicine and Hygiene, and the extant Transactions of the Royal Society of Tropical Medicine and Hygiene. As a surgeon, he argued for a new concept of hepatic lobulation based on the vascular supply, and became recognized as the father of the surgical anatomy of the liver. The scope of Cantlie's achievements is rivalled by few physicians, and his legacy remains with us to this day.

China↗
PubMed1999

The role of glutathione in p-aminophenol-induced nephrotoxicity in the mouse.

p-Aminophenol (PAP) produces nephrotoxicity in rats through a mechanism presumably involving oxidation and conjugation with glutathione (GSH). Recently it was found that PAP also causes nephrotoxicity in mice as evidenced by elevated blood urea nitrogen (BUN) and serum creatinine levels. The objective of this study was to further investigate the mechanism and elucidate the role of GSH in PAP-induced nephrotoxicity in the mouse. Male C57BL/6 mice injected i.p. with various doses of PAP were sacrificed at 12 hr for measurement of BUN and serum creatinine levels and determination of the extent of renal cortical nonprotein sulfhydryl (NPSH) and GSH depletion. PAP depleted renal cortical NPSH content in a dose- and time-dependent manner. Depletion of NPSH in mouse kidney did not occur at PAP doses below 600 mg/kg. Buthionine sulfoximine, an inhibitor of GSH synthesis, decreased nephrotoxicity. Ascorbate, a reducing agent, prevented PAP-induced nephrotoxicity and attenuated renal cortical NPSH depletion. However, acivicin and aminooxyacetic acid, inhibitors of gamma-glutamyltranspeptidase and beta-lyase, respectively, did not prevent toxicity in the mouse. Piperonyl butoxide, an inhibitor of cytochrome P-450 enzymes, enhanced nephrotoxicity and renal cysteine depletion but not GSH depletion. The results suggest that PAP-induced nephrotoxicity in the mouse may involve oxidation and formation of a GSH conjugate.

Aminophenols↗
PubMed1998

The relationship of Helicobacter pylori colonization, the serum pepsinogen A level, and gastric resection.

The serum levels of pepsinogen A (PGA) were measured in patients who underwent various forms of gastric resection to assess whether Helicobacter pylori (HP) colonization has any influence. Included in this study were 48 patients who underwent subtotal gastrectomy for a peptic ulcer (SGPU), 36 who underwent radical subtotal gastrectomy for gastric carcinoma (SGGC), 16 who underwent truncal vagotomy plus antrectomy (TV + AE), 24 with recurrent ulcer (RU) and 27 who underwent total gastrectomy (TG). The mean serum PGA levels in these five groups and in 40 healthy controls were 49.1 +/- 30.4 ng/ml, 30.0 +/- 14.8 ng/ml, 44.8 +/- 21.7 ng/ml, 66.4 +/- 42.8 ng/ml, 8.7 +/- 3.0 ng/ml, and 94.7 +/- 27.9 ng/ml, respectively. All patients except those with RU showed a diminished PGA level. The HP colonization rates of the patients who underwent partial resection were 45.8%, 22.2%, 50%, and 54.2%, respectively (P < 0.05). Age, gender, smoking, the type of gastroenterostomy, and underlying disease did not exert any influence on the measured PGA levels. However, higher PGA levels were observed in HP-colonized patients who either underwent SGPU or had RU. We conclude that various forms of distal gastrectomy, but not RU, elicit an indistinguishable acid secretory ability while HP colonization is responsible for the higher serum PGA levels in some patients following peptic ulcer surgery.

Aged↗
PubMed1998

Accurate detection of Smith-Lemli-Opitz syndrome carriers by measurement of the rate of reduction of the ergosterol C-7 double bond in cultured skin fibroblasts.

The activity of ergosterol delta 7-reductase (3 beta-hydroxysteroid delta 7-reductase) was measured in cultured skin fibroblasts from 7 controls, 10 Smith-Lemli-Opitz syndrome (SLOS) patients, and 10 parents (obligate carriers). The fibroblasts were exposed to delipidated medium supplemented with lovastatin for 24 h and the enzyme activity was determined by incubating cell-free homogenate with ergosterol (ergosta-5,7,22-trien-3 beta-ol) and measuring the mass of brassicasterol (ergosta-5,22-dien-3 beta-ol) formed by gas chromatography-mass spectrometry with selected-ion monitoring. In carriers, the activity was significantly lower than in controls (22 +/- 2 vs 65 +/- 10 pmol/min per mg protein, p < 0.0005), and no overlap was observed. The mean activity in carriers' fibroblasts was more than 100 times higher than in patients' cells (0.2 pmol/min per mg protein). The use of ergosterol avoids the many problems caused by the instability and lack of availability of radiolabelled 7-dehydrocholesterol. The present method makes it possible to discriminate SLOS carriers from both controls and patients using a commercially available substrate and common analytical equipment.

Cells, Cultured↗
PubMed1998

Inhibition of gastric emptying and intestinal transit by amphetamine through a mechanism involving an increased secretion of CCK in male rats.

1. The effect of amphetamine on gastrointestinal (GI) transit and the plasma levels of cholecystokinin (CCK) were studied in male rats. 2. Gastric emptying was inhibited both acutely and chronically by the administration of amphetamine. GI transit was decreased by the acute administration of amphetamine but not affected by the chronic administration of amphetamine. 3. Plasma CCK levels were increased dose-dependently by amphetamine. 4. Proglumide, a CCK receptor antagonist, prevented amphetamine-induced inhibition of gastric emptying and the decrease in GI transit in male rats. 5. The selective CCK(A) receptor antagonist, lorglumide, dose-dependently attenuated the amphetamine-induced inhibition of gastric emptying in male rats. In contrast, the selective CCK(B) receptor antagonist, PD 135,158, did not reverse the effect of amphetamine on gastric emptying. 6. Both lorglumide and PD 135,158 reversed the inhibitory effect of amphetamine on GI transit in male rats. 7. These results suggest that amphetamine-induced inhibition of gastric emptying and intestinal transit is due in part to a mechanism associated with the hypersecretion of endogenous CCK.

Amphetamines↗
PubMed1998

Nizatidine in combination with amoxycillin and clarithromycin in the treatment of Helicobacter pylori infection.

BACKGROUND: The efficacy of H2-antagonists in combination with antibiotics in curing Helicobacter pylori infection remains controversial, and it is uncertain whether double dose H2-antagonist therapy is superior to standard dose. AIM: To determine the efficacy of two doses of nizatidine in combination with two antibiotics in the treatment of H. pylori. METHODS: A randomized controlled trial was conducted in 160 patients comparing nizatidine 150 mg with 300 mg b.d. (standard vs. double dose), in combination with clarithromycin (500 mg) and amoxycillin (1000 mg) b.d. for 14 days, in Australia and Taiwan. Compliance was based on a clinical assessment and pill count. H. pylori status was determined by histology (antrum and corpus) and CLO-test. RESULTS: Baseline clinical and endoscopic findings were similar in both arms of the study. Based on an intention-to-treat analysis, cure of H. pylori was achieved in 78% (95% CI: 70.4-85.4%) in the standard nizatidine dose arm and 70% (95% CI: 61.6-78.2%) in the double dose arm (P=0.2). Similar cure rates were observed in ulcer and non-ulcer patient groups. Compliance was excellent in the single and double dose arms (85 and 91%, respectively). CONCLUSIONS: The combination of nizatidine in standard or double dose with clarithromycin and amoxycillin is similarly efficacious in curing H. pylori infection.

Adult↗
PubMed1998

The liver in traditional Chinese medicine.

Medical thinkers in China visualized the liver in microcosmal and macrocosmal terms. An anatomical tradition did not exist, hence the liver was described grossly in broad outline. It was recognized as being functionally important in the movement of qi (vital energy) and storage of xue ('blood'). The liver corresponded to various phenomena in both the natural and social orders, according to the scheme of yin yang and five phases. These interrelationships provided the basis for the diagnosis and treatment of liver dysfunctions. The disorders fell into three general groups: (i) hepatic qi stasis; (ii) hepatic yang excess with yin deficiency; and (iii) hepatic yin insufficiency. The signs and symptoms represented the logical outcomes of the disturbed physiology. Acupuncture, moxibustion and herbal drugs were used to redress the imbalance of hepatic qi and yin-yang. The impact of Western medicine led traditional authors to recognize the hepatobiliary role in bile secretion and in jaundice. The exchange between the Western and Chinese medical traditions revealed that active agents were included in the Chinese formulary, such as glycyrrhizin, which has recently been shown to be beneficial in chronic viral hepatitis.

Humans↗
PubMed1998

Helicobacter pylori colonization does not influence the symptomatic response to prokinetic agents in patients with functional dyspepsia.

Functional dyspepsia (FD) is very common, but the pathogenesis of Helicobacter pylori leading to FD is still debated. The aim of this study was first to evaluate the impact of H. pylori colonization on the efficacy of Paspertase (a metoclopramide plus exogenous enzymes regimen for FD patients) and, second, to compare the prevalence of H. pylori infection in FD patients with the general population. Seventy-four consecutive FD patients were enrolled undergoing Paspertase treatment. The symptomatic response was evaluated according to 1-4 scales of six main dyspeptic symptoms (i.e. epigastric pain/discomfort, early satiety, heartburn, nausea/vomiting, abdominal fullness/bloating, and belching). Nine hundred and seventy healthy subjects undergoing a paid physical check-up were included to study the status of H. pylori colonization. The demographic data and basal symptom scores between 43 H. pylori-positive and 31 H. pylori-negative patients were not significantly different. Total and individual symptom scores improved significantly after 4 weeks of Paspertase therapy (P < 0.05), irrespective of H. pylori infection. The prevalences of H. pylori were very similar in FD patients and the general population (58.1 vs 58.0%, NS). In conclusion, these observations suggest that H. pylori colonization is not significant in FD patients of Taiwan while a short-term prokinetic medication is effective for these patients, irrespective of H. pylori status.

Adult↗
PubMed1998

Oxidative stress: an important phenomenon with pathogenetic significance in the progression of acute pancreatitis.

BACKGROUND: Reactive oxygen species and related oxidative damage have been implicated in the initiation of acute pancreatitis. Changes in these parameters during disease progression merit further investigation. AIMS: To evaluate changes and the clinical relevance of superoxide radicals, endogenous antioxidants, and lipid peroxidation during the course of acute pancreatitis. PATIENTS AND METHODS: Superoxide radicals (measured as lucigenin amplified chemiluminescence), ascorbic acid, dehydroascorbic acid, alpha tocopherol, and lipid peroxidation (measured as thiobarbiturate reactive substances) were analysed in blood samples from 56 healthy subjects, 30 patients with mild acute pancreatitis, and 23 patients with severe acute pancreatitis. The association with grades of disease severity was analysed. Measurements were repeated one and two weeks after onset of pancreatitis. RESULTS: In the blood from patients with acute pancreatitis, there were increased levels of the superoxide radical as well as lipid peroxides. There was notable depletion of ascorbic acid and an increased fraction of dehydroascorbic acid. Changes in alpha tocopherol were not great except in one case with poor prognosis. Differences between severe and mild acute pancreatitis were significant (p < 0.01). Variable but significant correlations with disease severity scores were found for most of these markers. The normalisation of these indexes postdated clinical recovery one or two weeks after onset of disease. CONCLUSIONS: Heightened oxidative stress appears early in the course of acute pancreatitis and lasts longer than the clinical manifestations. The dependence of disease severity on the imbalance between oxidants and natural defences suggests that oxidative stress may have a pivotal role in the progression of pancreatitis and may provide a target for treatment.

Acute Disease↗
PubMed1998

Experimental assessment of the feasibility of integrating an endoscopic imaging system into an existing hospital information system.

The National Cheng Kung University (NCKU) Hospital operates a comprehensive integrated hospital information system. This was designed and installed as an integral component of the building of the hospital, which opened in 1988. The information system provides a service to all staff in the hospital, administrative and clinical, across the whole of the hospital. To make sure that the information is accessible, where and when it is needed, a comprehensive communications network consisting of both hardware and software mechanisms supports the information system. This paper explores the requirements for a computerised image system for endoscopy and assesses two approaches to the implementation of such a system, as a stand-alone system and as a subsystem of the NCKU hospital information system already in place. The latter would satisfy the original design specification of developing a single system to cover all aspects of hospital operation but places additional demands on the endoscopy systems designer to ensure integration. Both operational modes are set out in the paper and their implications assessed.

Computer Systems↗
PubMed1998

Community medical care monitoring system for chronic patient.

The chronic disease usually can not be cured well but controlling by the daily care activity, regular diagnosis and dosage under the physician's instructions. In this research, we propose a community medical care monitoring model for monitoring and managing the chronic patients of community through the WWW (World Wide Web) service network and/or telephone voice service network. It can collect more patients' physiological data measured at home or community health agent. Therefore, the chronic disease patients will be getting better cure from his doctor's diagnosis due to the patient's effort.

Chronic Disease↗
PubMed1998

7-Dehydrocholesterol down-regulates cholesterol biosynthesis in cultured Smith-Lemli-Opitz syndrome skin fibroblasts.

The Smith-Lemli-Opitz syndrome (SLOS) is a common birth defect-mental retardation syndrome caused by a defect in the enzyme that reduces 7-dehydrocholesterol to cholesterol. Because of this block, patients' plasma cholesterol levels are generally low while 7-dehydrocholesterol concentrations are markedly elevated. In addition, plasma total sterols are abnormally low and correlate negatively with the percent of 7-dehydrocholesterol (r = -0.65, P < 0.0001) suggesting that 7-dehydrocholesterol might inhibit the activity of HMG-CoA reductase. Cultured skin fibroblasts from SLOS patients grown in fetal bovine serum or for 1 day in delipidated medium contain little 7-dehydrocholesterol (3 +/- 1% of total sterols) and HMG-CoA reductase activities are indistinguishable from that measured in control cells. However, raising the 7-dehydrocholesterol concentration to 20 +/- 3% of total sterols, equal to the mean proportion in plasma of SLOS patients, by either growing cells for 1 week in delipidated medium or adding 20 microg/ml 7-dehydrocholesterol directly to the cells reduced HMG-CoA reductase activities from 74 +/- 7 to 9 +/- 2 pmol/min per mg protein, or from 92 +/- 22 to 16 +/- 4 pmol/min per mg protein, respectively (P < 0.01). In contrast, adding 20 microg/ml cholesterol evoked a 2- to 4-fold lesser suppression of activity (39 +/- 8 pmol/min per mg protein, P < 0.05, vs. 7-dehydrocholesterol). HMG-CoA synthase and LDL binding were inhibited equally by 7-dehydrocholesterol and cholesterol. Ketaconazole prevented the down-regulation of HMG-CoA reductase by 7-dehydrocholesterol, suggesting that an hydroxylated derivative of 7-dehydrocholesterol may be especially important in suppressing cholesterol synthesis. These results demonstrate that 7-dehydrocholesterol, perhaps as an hydroxylated derivative(s), is a very effective feedback inhibitor of HMG-CoA reductase.

Cells, Cultured↗