Biomedical subjects

D C Wu

Publications and source records attributed to D C Wu.

At least 37 records · Page 2Linked to original sources

PubMed2000

Lifestyle habits and gastric cancer in a hospital-based case-control study in Taiwan.

OBJECTIVES: The aim of this study was to evaluate the effect of lifestyle habits on the risk of primary gastric cancer. METHODS: A hospital-based case-control study of matched pairs was conducted in Kaohsiung, Taiwan, from 1992 to 1996. The study included 649 subjects (152 cases and 497 controls). All subjects were personally interviewed face-to-face by a trained interviewer using a structured questionnaire to collect data about lifestyle. An average of approximately three controls were matched to each case based on age (+/-3 yr), sex, and time of hospitalization (+/-2 wk). Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to evaluate results, and a multivariate analysis of the data was performed using a conditional logistic regression model. RESULTS: A significantly elevated risk of contracting gastric cancer was observed in cigarette smokers (OR: 2.7, 95% CI: 1.5-4.3), but not in drinkers of alcoholic beverages (OR: 1.5, 95% CI: 0.9-3.2). A synergistically augmented relationship (multiplication effect) was found between smoking and drinking alcohol for controlling the major confounders. The combined adjusted ORs for all subjects with gastric cancer were 3.0 (95% CI: 1.4-7.1) for current smokers and 1.7 (95% CI: 1.2-4.4) for ex-smokers. Furthermore, a statistically significant positive dose-response trend in gastric cancer was demonstrated based on the age at which smoking was initiated, the duration of the habit, the number of cigarettes smoked per day, and the degree of smoke inhalation. We did not find any association between the other risk factors and gastric carcinogenesis. CONCLUSIONS: Our findings provide further evidence that in Taiwan, cigarette smoking may play the most harmful role in the initial development of gastric cancer, and that drinking alcohol may promote the process.

Alcohol Drinking↗

PubMed2000

Expression of aquaporins in the renal connecting tubule.

The renal connecting tubule (CNT) is a distinct segment that occurs between the distal convoluted tubule (DCT) and the cortical collecting duct. On the basis of its characterization in rabbit it is widely believed that connecting tubule cells have a low permeability to water and do not respond to vasopressin. Here we utilize segment-specific markers and specific aquaporin antibodies to characterize expression of water channels in CNT of the rat by immunocytochemistry. Colocalization of aquaporin 2 (AQP2), AQP3, and AQP4 with Na(+), Ca(2+) exchanger (NCX), a transporter characteristic of the connecting tubule, gave heterogeneous labeling. There was aquaporin labeling in many but not all regions labeled by NCX. Colocalization of AQP2 with AQP3 and with AQP4 showed that AQP3 and AQP4 labeling were always accompanied by AQP2. Immunogold labeling and electron microscopy showed that NCX-labeled cells with AQP2 labeling had the morphology of CNT cells, whereas NCX-labeled cells without AQP2 labeling were DCT cells. The latter regions were identified as the late region of the DCT known as DCT2. Additionally, regions of CNT lacking AQP2 labeling could be identified in Brattleboro rats not treated with vasopressin but not in such animals chronically treated with deamino-Cys(1),D-Arg(8)-vasopressin (dDAVP). Quantitative analysis of labeling was consistent with expression of AQP2 over a longer region of CNT after dDAVP exposure.

Animals↗

PubMed2000

Simplified 13C-urea breath test for the diagnosis of Helicobacter pylori infection--the availability of without fasting and without test meal.

The conventional 13C-urea breath test (13C-UBT) for detecting Helicobacter pylori infection was performed during fasting state and with a test meal to delay gastric emptying during the test. For the convenience of propagating this test, we assessed the availability of non-fast and without test meal in 13C-UBT for the diagnosis of H. pylori infection. One hundred and five consecutive patients who received endoscopic examination were studied. All of them received endoscopic biopsy for urease test, culture and histopathology to determine whether there was a presence of H. pylori infection. Each patient received four separate 13C-UBT under the following four testing conditions. Test I) fasting state with test meal (100 ml fresh milk), Test II) non-fast (taking usual food) but with test meal, Test III) fasting state without test meal, and Test IV) non-fast and without test meal. The excess delta 13CO2 values were calculated via the breathed samples that were collected at 15 minutes after ingestion of 13C-urea. There were 61 H. pylori positive and 44 negative patients in this study, with an excess delta 13CO2 values 3.0, 4.0, 3.5 and 4.0 as a cut-off value in the four tests respectively, according to the ROC curve. The results of test I, a conventional procedure, had a good correlation with the gold standard. The sensitivity and specificity were 100% and 95% respectively. The alternative procedures in other tests also have high sensitivity and specificity at 15-minute detecting time. The sensitivity of the tests II, III and IV at 15-minute detecting times were 98%, 98% and 100%, and the specificities of those were 95%, 98% and 95% respectively. We therefore suggest that fasting and test meal possibly be omitted when the cut-off value is 4.0 per mil in the simplified 13C-UBT (non-fast and without test meal, and detection at 15 minutes after ingestion of 13C-urea) which is a simple and available procedure for clinical diagnosis of H. pylori infection.

Adult↗

PubMed1999

Effects of bis(7)-tacrine, a novel anti-Alzheimer's agent, on rat brain AChE.

The anticholinesterase effects of bis(7)-tacrine were compared with tacrine in vitro and in vivo. Based on IC50 ratios, the dimeric analog bis(7)-tacrine was, in a reversible manner, up to 150-fold more potent and 250-fold more selective than tacrine for acetylcholinesterase (AChE) over butyrylcholinesterase (BChE). Following a single oral administration, both bis(7)-tacrine and tacrine produced dose-dependent inhibitions of AChE in rat brain, but bis(7)-tacrine exhibited higher efficacy and AChE/BChE selectivity than tacrine. The anti-AChE efficacy of bis(7)-tacrine was quite similar following an oral or i.p. administration, but tacrine showed much lower efficacy when administered orally than when given i.p. These findings suggest bis(7)-tacrine, a highly potent and selective inhibitor of AChE, can probably be used as an improved drug in the palliative treatment of AD.

Acetylcholinesterase↗

PubMed1999

Endoscopic hydrogen peroxide spray may facilitate localization of the bleeding site in acute upper gastrointestinal bleeding.

BACKGROUND AND STUDY AIMS: A major problem encountered in the emergency endoscopic management of acute upper gastrointestinal (UGI) bleeding is poor localization of the bleeding site, which can be obscured by blood or clots. Traditional attempts to overcome this problem have been by physical methods, which have usually proved unsatisfactory. The aim of this prospective study was to show that hydrogen peroxide can be used as a dissolution agent, resulting in an alteration of the characteristics of blood clots and allowing a clearer visual field. PATIENTS AND METHODS: Twenty patients with acute UGI bleeding (13 male, seven female) were included in the study. The suspected site of bleeding was initially sprayed with 200 ml of saline and then with 25-175 ml of 3 % H2O2. Pictures of the visual field were taken before and after irrigation with both saline and H2O2. These pictures were evaluated by three gastroenterologists and scored using the following visual clearance scoring system: -3, marked worsening of visual field; -2, moderate worsening; -1, slight worsening; 0, no change; +1, slight improvement; +2, moderate improvement; + 3, marked improvement. In cases of active oozing or spurting, after initial hemostasis was achieved the bleeding point was injected with pure ethanol or cauterized with a heater probe. In order to assess the safety of 3 % H2O2 endoscopic biopsies of the antrum and the duodenal bulb were performed before and 30 minutes after its use and examined by a pathologist. RESULTS: There was a significant improvement in the mean visual clearance score after irrigation with H2O2 compared to irrigation with saline alone (2.13 vs. 0.43, P<0.001). During endoscopic examination there were 19 patients with active oozing from the ulcer base covered by an adherent blood clot; 12 of these (63.1%) achieved initial hemostasis after H2O2 spraying. Eleven of 18 (61.1 %) patients complained of a mild epigastric burning sensation during H2O2 irrigation. There was no clinically significant change in the histology of the antrum and the duodenal bulb after H2O2 therapy. CONCLUSIONS: We concluded that H2O2 is a safe and effective way to clear the visual field, facilitating the localization of the bleeding site during emergency endoscopy for acute UGI bleeding, with only mild side effects. In some cases H2O2 therapy can also induce temporary hemostasis. We recommended the use of hydrogen peroxide to improve endoscopic visualization, especially in cases where an adherent blood clot covers the suspected bleeding site.

Adult↗

PubMed1999

The trefoil gene family are coordinately expressed immediate-early genes: EGF receptor- and MAP kinase-dependent interregulation.

The trefoil gene family of mucus cell-secreted proteins is a critical mediator of gastrointestinal mucosal restitution. Transcription of trefoil genes is induced during mucosal repair, but the regulatory mechanisms involved are unknown. Mice deficient in the intestine-specific peptide intestinal trefoil factor (ITF), in which colonic restitution is lethally impaired, showed reduced expression of the gastric trefoil genes SP and pS2, suggesting that trefoil peptides may individually regulate transcription of the entire family. In gastric cell lines, the trefoils were shown to act in a manner suggestive of immediate-early genes capable of auto- and cross-induction through cis-acting regulatory regions. Trefoil-mediated transcriptional regulation required activation of the Ras/MEK/MAP kinase signal transduction pathway. EGF receptor (EGF-R) activation was also necessary for trefoil auto- and cross-induction, and both spasmolytic polypeptide (SP) and ITF stimulation of gastric cell lines led to phosphorylation of EGF-R. Nevertheless, ITF and ITF-thioredoxin cell surface binding at 4 degrees C colocalized not with EGF-R, but with CD71, which is found in clathrin-coated pits, suggesting that integration of trefoil peptide responses may occur after internalization. As EGF-R expression is itself strongly induced after mucosal damage, the trefoil/EGF-R relationship may be pivotal in the generation and maintenance of the mucosal repair phenotype.

Animals↗

PubMed1999

The hemodynamic changes of gastroduodenal regional blood flow after Helicobacter pylori eradication in patients with duodenal ulcer scar.

Duodenal ulcer (DU) is frequently accompanied by Helicobacter pylori (Hp) infection and associated with the imbalance of aggressive factors and defensive factors. To investigate the possible relationship between Hp and regional gastric blood flow, 26 endoscopically proved DU (scar stage) and Hp infection patients were included and received triple therapy (colloid bismuth subcitrate 120 mg qid for 4 weeks, amoxicillin 500 mg qid for 2 weeks and metronidazole 250 mg tid for 2 weeks). Regional gastroduodenal blood flow (RGDF) was measured at DU scar area and antrum lesser curvature site by laser Doppler flowmetry during endoscopic examination, before and one month after triple therapy. In 22 patients with Hp eradication the RGDF was significantly elevated at antrum lesser site after triple therapy (p < 0.05) but there was no difference at DU scar area. However, in 4 patients without Hp eradication no difference of RGDF in these two points was found. Therefore, Hp appears to have direct effects on gastric microcirculation.

Adult↗

PubMed1998

Quantification of Helicobacter pylori infection: Simple and rapid 13C-urea breath test in Taiwan.

The 13C-urea breath test (13C-UBT) is a non-invasive method for detecting Helicobacter pylori. This study was performed to determine the cutoff value and evaluate the sensitivity and specificity of 13C-UBT in Taiwan. 13C-Urea (100 mg of 99% 13C-labeled urea) was dissolved in 50 ml sterile water for the test. The test meal for delaying gastric emptying was 100 ml fresh milk. Patients fasted for at least 6h. A baseline breath sample was collected 5 min after they had the test meal. Two other samples were collected at 15 and 30 min after the patients ingested the 13C-urea. The test was evaluated in 352 patients after routine upper gastrointestinal endoscopy, and the urease test, culture, and histopathology were taken as the gold standards for detecting H. pylori. According to the receiver operating characteristic (ROC) curves, we chose values of 2.8 and 4.2 excess delta 13CO2 per mil as the cut-off values for 15 and 30 min, respectively, post 13C-urea. The sensitivity and specificity of 13C-UBT were 99% and 93% at 15 min, and 98% and 93% at 30 min post 13C-urea, respectively. The 13C-UBT breath test is an efficient non-invasive method of high sensitivity and high specificity for detecting H. pylori infection. We suggest that the use of fresh milk as the test meal and the detection of excess delta 13CO2 15 min after the ingestion of 13C-urea are suitable for the clinical use of 13C-UBT. This test is simple and rapid.

Adolescent↗

PubMed1997

Mitomycin-C induced hemolytic uremic syndrome: a case report and literature review.

Hemolytic uremic syndrome spontaneously arises in a few patients with advanced cancer, but it is more commonly related to the use of certain chemotherapeutic agents. Mitomycin-C is, etiologically, the most common causative agent inducing hemolytic uremic syndrome, in a dose dependent manner. We report this syndrome, attributable to mitomycin-C at a cumulative dose of 40 mg/m2, in a gastric cancer patient. A 42-year-old female with stage III gastric cancer underwent radical gastrectomy and was given mitomycin-C at 10 mg/m2 intravenously every four weeks as adjuvant therapy. Hemolytic uremic syndrome was diagnosed three months after the last dose of mitomycin-C administration. The most prominent symptoms included pallor, hypertension and anasarca, with laboratory evidence of microangiopathic hemolytic anemia, azotemia and hyperkalemia. Her disease was progressive, but fortunately stabilized after staphylococcus column A dialysis. Her disease remained in remission for 24 months from the time of diagnosis, and then relapsed in the form of peritoneal carcinomatosis with partial intestinal obstruction.

Adenocarcinoma↗

PubMed1997

Retardation of pain development: a case of recovery from congenital insensitivity to pain.

Congenital analgesia is a rare genetic disorder. We report here that a 12-year-old boy was able to recover from congenital insensitivity to pain. Neurological examinations revealed that there was a 'stocking' distribution of pain decrement on the lower extremities under the patient's knee joints. Magnetic Resonance Imaging (MRI) of his brain showed gyrus thinning with sulcus widening at both sides of the parietal lobe. Southern blot hybridization probed with cDNAs of various opioid receptors did not detect any significant abnormality. Our results suggest that this rare case may not be genetically determined.

Arthropathy, Neurogenic↗

PubMed1996

Impaired defense of intestinal mucosa in mice lacking intestinal trefoil factor.

The mechanisms that maintain the epithelial integrity of the gastrointestinal tract remain largely undefined. The gene encoding intestinal trefoil factor (ITF), a protein secreted throughout the small intestine and colon, was rendered nonfunctional in mice by targeted disruption. Mice lacking ITF had impaired mucosal healing and died from extensive colitis after oral administration of dextran sulfate sodium, an agent that causes mild epithelial injury in wild-type mice. ITF-deficient mice manifested poor epithelial regeneration after injury. These findings reveal a central role for ITF in the maintenance and repair of the intestinal mucosa.

Animals↗

PubMed1995

Retinal blood vessel width measured on color fundus photographs by image analysis.

The purpose of this paper was to develop a technique using computerized image analysis to measure the width of retinal arteries and veins on color fundus photographs. The width of the retinal vessel was determined from digitized fundus photographs by programs based on edge detection and boundary tracing. The average vessel width was determined at different distances or eccentricities from the center of the optic disc and using various lengths of vessel segment. Measurements of superior and inferior temporal vessel width for 20 eyes by 2 operators showed that about 75% of the measurements could be obtained without the use of plan points. The average percent coefficient of variation of the measurements was 2.17% for 3 measurements of each vessel. This technique provides a reproducible and objective method for obtaining the following parameters: the edges of the vessel, the length of the vessel segment to be measured, location of the measurement along the vessel and subsequent retinal vessel width. This technique is readily suitable for application to clinical studies particularly clinical trials.

Adult↗

PubMed1995

Does Helicobacter pylori infection play a role in the pathogenesis of non-ulcer dyspepsia--a study of gastric emptying time.

UNLABELLED: To investigate the relationship between gastric motility and Helicobacter pylori infection in patients with non-ulcer dyspepsia, 28 patients and 10 asymptomatic healthy persons underwent gastroduodenal endoscope examinations and scintigraphic test of solid phase gastric emptying time using Chinese fried rice as a test meal. Clinical symptoms were also recorded using questionnaires for scoring. Half emptying times for ingested food (t1/2) between H. pylori infected (190.86 +/- 112.53 minutes) and uninfected patients (227.69 +/- 179.29 minutes) were not different statistically. Seven of the 15 patients with H. pylori infection (46.6%) had delayed gastric emptying time (t1/2 > 197.7 minutes), compared to 4 out of 13 without infection (30.07%) (p > 0.05). There was also no association between the status of H. pylori infection and severity of clinical symptoms (total symptoms scores: H. pylori positive: 10.07 +/- 3.84; H. pylori negative: 7.62 +/- 2.25) (p > 0.05). Seven patients from whom H. pylori was found to have been eradicated using triple therapy (colloid bismuth subcitrate 120 mg q i d, tetracycline 500 mg q i d and metronidazole 250 mg q i d for 14 days) did not show significant changes in gastric emptying time (before: 171.14 +/- 128.13; after: 158.57 +/- 182.49 minutes) but showed improvement in total symptoms scores (before: 9.28 +/- 3.85; after: 3.85 +/- 4.22) (p = 0.0277). CONCLUSIONS: infection by H. pylori in patients with non-ulcer dyspepsia did not influence solid phase of gastric emptying time and was not associated with clinical symptoms. Eradication of H. pylori infection relieved the clinical symptoms of the patients with non-ulcer dyspepsia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Evaluation of the severity of Helicobacter pylori infection with urease test: its correlation with histopathology and bacterial density.

In 69 patients, the severity of Helicobactor pylori (H. pylori) infection was evaluated by bacterial density of tissue implants and inflammatory responses by histology. The specimens were taken from gastric angle and antrum (greater and lesser curvature sides) by gastroduodenal endoscopy. In urease test, the severity was measured in 3 grades according to color change of the agar: those change are within 30 minutes (grade 3), 30 minutes to 3 hours (grade 2), and 3 to 6 hours (grade 1), respectively; while the grade 0 indicated no color change occurring 6 hours after tissue inoculation. The severity of infection was assessed according to the bacterial density under high power microscopic fields (Gram's stain). Grade 0 indicated no bacterium seen; grade 1, only 1 to 10 bacteria at all fields; grade 2, 1 to 3 bacteria in each high power field; and grade 3 was 4 bacteria or more on average in each high power field. The degree of inflammatory response was evaluated by inflammatory cell infiltration (H & E stain) and classified into grade 0, 1 and 2, which indicated the inflammatory cell infiltration below 50%, between 50% and 75%, and above 75%, respectively. There are no positive relationships among urease test reaction time, bacterial density grading and degrees of inflammatory cell infiltration. Clinically, the reaction time of urease test cannot reflect the severity of H. pylori infection semi-quantitatively, either in terms of bacterial density or cellular inflammatory response.

Adult↗

PubMed1994

Current studies on biological effects of low level internal irradiation.

The biological effects of relative low level internal irradiation were introduced. 1. Life span studies on carcinogenesis. Pacific Northwest Laboratory observed 3782 rats given a single inhalation of 239Pu O2 at initial lung burden ranging from 0.25 to 180 nCi. Significant life span shortening was found at lung dose > 8 Gy and it was indicated that the presence of a "possible" threshold of about 1 Gy for lung tumor formation. 2. Health effects of radon and its progeny. Both experimental and epidemiological survey were studied. The nominal probability coefficient (fatality) for the public and workers are 7.90 x 10(5) per mJhm-3 (2.77 x 10(-4) per working level month, WLM). 3. Health effects on 3H on postnatal brain development and neurobehavior, genetic effects, carcinogenic effects and adaptive effects of 3H were investigated. 4. Study on the effects of neuroendocrine system under low level irradiation of 75Se (Auger electron emitter) and 35S (beta-particles emitter). The results showed that the neuroendocrine system is very sensitive to small dose of internal irradiation.

Animals↗

PubMed1994

[Flow cytometry in diagnosis and treatment of bladder tumor].

The cellular DNA contents of 139 bladder irrigations from 52 cases of bladder tumors were determined by flow cytometry. The results were compared with those of pathological grading and exfoliative cytology. It is suggested that cytological results were less accurate than DNA contents. High aneuploid DNA contents in tumor cells were marked by low grade and deep penetration of the bladder tumor. Total cystectomy was needed for bladder tumor with high aneuploid DNA, and partial cystectomy and TURBT for that tumor showed high recurrence with instillation of BCG. The results showed that DNA content of tumor is correlated with the nuclear grade, especially in poorly differentiated neoplasms, but flow cytometry can not replace cystoscopy examination.

Adult↗

PubMed1992

[Flow cytometric analysis of DNA in esophageal cancer].

Malignancy is the first of the ten leading causes of death in Taiwan area, however, since 1978, esophageal cancer is on the first ten causes of malignancy. Esophageal cancer is an aggressive neoplasm with a generally poor prognosis. This is usually related to the advanced stages of the neoplasm at presentation and at diagnosis. In this study, the DNA content in tumor was analyzed by flow cytometry, and compared it with clinical- pathological data, especially the survival time. All thirty seven cases (36 male, 1 female, mean age: 56.5 +/- 10.3 y/o) received operation at Kaohsiung Medical College Hospital in the past 11 years and 29 cases (27 male, 2 female, mean age: 62.2 +/- 9.6 y/o) proved to be esophageal cancer by endoscopic biopsy were assayed in this study. The formalin fixed-paraffin embedded block is used to analyze DNA content by flow cytometry. After comparing these results with clinical-pathological data, there were no significant difference in sex, age, duration, tumor location and length. However, there is a significant correlation between ploidy and tumor cell differentiation, that is, most of the diploid cells were well differentiated while most of the aneuploid cells were poorly differentiated. The median survival time of diploid cases was 325 days which was longer than the 277 days in aneuploid group, but there was no significant difference between these two groups. The same result was noticed in DNA index. Multiple variables analysis of prognostic factors disclosed that there were significant difference in correation with age tumor location tumor length, and whether there was combined radiotherapy and operation. But there were no significant relationship between survival and DNA ploidy DNA index distant metastasis surrounding tissue invasion sex duration and tumor cell differentiation. These data suggest that DNA folw cytometry analysis alone, may not provide a sueful biologic basis for the variable prognosis seen with esophageal tumors.

Aged↗

PubMed1991

Intraocular pressure and the rate of visual field loss in chronic open-angle glaucoma.

We measured the rate of change of visual field threshold values over time (mean follow-up, 44.9 +/- 17.4 months) by trend analysis in 40 eyes of 40 patients with chronic open-angle glaucoma. Twenty-eight eyes had stable visual fields, and two eyes had significant visual field improvement. Ten eyes had significant visual field deterioration and showed a correlation between indices of intraocular pressure (standard error of the mean, P = .02; standard deviation, P = .04; and range, P = .05) and the rate of visual field loss in the superonasal region of the visual field, such that the greater the variation of intraocular pressure the greater the rate of loss. The group losing visual fields had a higher mean visual field threshold value and significantly less optic disk pallor and cupping at the start of the study than the stable visual field group. Thus, a significant rate of visual field loss occurred at an earlier stage of the disease and showed a correlation with intraocular pressure in this stage.

Aged↗