Search PubMed⌕ Search

Biomedical subjects

K J Chang

Publications and source records attributed to K J Chang.

At least 73 records · Page 4Linked to original sources
PubMed1998

Effects of taurine supplementation on lipid peroxidation, blood glucose and blood lipid metabolism in streptozotocin-induced diabetic rats.

The purpose of this study was to determine the effect of taurine on several complications of diabetes, including oxidative stress, glucose intolerance and blood lipid profile. Sprague Dawley male rats were fed an experimental diet for 7 weeks, at which time they were maintained on drinking water with or without 1% taurine. The experimental period was 7 weeks and the rats were administered streptozotocin (STZ) to induce diabetes. Thiobarbituric acid reactive substances (TBARS) content was increased following the STZ injection, but was lowered by prior treatment with taurine. The primary diabetic symptoms, such as polydipsia and polyuria, were ameliorated in rats supplemented with taurine before the STZ injection. Plasma triglyceride (TG) levels of the diabetic group were decreased by taurine supplementation, although plasma total cholesterol (T-chol) and HDL cholesterol (HDL-chol) were not different among the groups. LDL cholesterol (LDL-chol) levels of the control group were significantly decreased by taurine supplementation, however, the time of taurine administration affected the response of the diabetic group; only diabetic rats treated with taurine after the administration of STZ showed a decrease in LDL cholesterol. Therefore, taurine inhibits lipid peroxidation and decreases blood TG and LDL-chol levels, however, the time and dose of taurine supplementation are variables that need to be considered in the treatment of diabetes.

Animals↗
PubMed1998

Abdominal sonography screening of clinically diagnosed or suspected appendicitis before surgery.

We conducted a prospective study to evaluate the value of abdominal sonography in the diagnosis of acute appendicitis and determine the need for abdominal sonography before operation. Altogether 191 patients with clinically diagnosed or suspected appendicitis underwent an abdominal sonography examination performed by a staff surgeon before operation. The sonographic findings are classified into three categories: appendicitis, other diseases, or normal screening. A total of 158 patients (82.7%) with positive findings of appendicitis proceeded to surgery; 18 patients (9.4%) were found to have other diseases, and they were treated for their conditions; and 15 patients (7.9%) with normal screening were discharged from the hospital and were reevaluated 2 weeks later. Only one patient had a false-negative finding. Of the 158 patients undergoing operation, 143 (90.5%) were proved to have appendicitis by the pathologic reports. A total of 32 negative appendectomies (16.8%) were prevented after sonographic examination. Abdominal sonography for detecting acute appendicitis had a sensitivity of 99.3%, a specificity of 68.1%, an accuracy of 91.6%, a positive predictive value of 90.5%, and a negative predictive value of 97.0%. The value of meticulous history-taking, physical examination, and laboratory tests cannot be overemphasized. Our experience suggests that patients with clinically diagnosed or suspected acute appendicitis should routinely undergo abdominal sonography examination, performed by an experienced surgeon, to further decrease the negative appendectomy rates.

Acute Disease↗
PubMed1998

High-dose therapy with peripheral blood stem cell (PBSC) support using an innovative mobilization regimen in patients with high-risk primary or chemoresponsive metastatic breast cancers.

High-dose therapy followed by peripheral blood stem cell (PBSC) support was performed in 29 patients with primary high-risk (Group I) or chemoresponsive metastatic (Group II) breast cancer patients. Group I patients had received PBSC mobilization within 4 weeks of modified radical mastectomy. Group II patients had to achieve minimal residual disease (MRD) by induction chemotherapy before being considered eligible for PBSC mobilization and high-dose therapy. An innovative FE120C regimen (5-FU 600 mg/m2, i.v., day 1; epirubicin 120 mg/m2, i.v., day 1; cyclophosphamide 600 mg/m2, i.v., day 1) plus G-CSF (300 microg/day, subcutaneous injection for 9 days, from day 4 post-FE120C) was used to mobilize PBSCs. After high-dose CTCb (cyclophosphamide 6,000 mg/m2, thiothepa 500 mg/m2, carboplatin 800 mg/m2, in 4 days), patients received PBSC infusion and daily C-CSF 300 microg subcutaneous injection. There were 19 and 16 patients enrolled into Group I and Group II, respectively. Ten of the Group II patients had achieved minimal residual disease (MRD) after induction chemotherapy. The median numbers of mobilized total CD34 + cells for Group I and Group II patients were 27.3 (9.2 to 114.1) x 10(6)/kg and 17.1 (5.9 to 69.1) x 10(6)/kg respectively. The median time to neutrophil recovery (ANC > or = 500/microL) was 8 and 9 days in Group I and II, respectively. The median time to platelet recovery (> or = 50,000/microL) was 10 and 15 days in Group I and II, respectively. No major treatment-related toxicities were noted. In Group I, 13 out of 19 patients (68.4%; 43-87%, 95% C.I.) remained recurrence-free with a median follow-up of 31 months (6 + to 55 + months). In Group II, 3 out of 10 patients (30%; 7-65%, 95% C.I.) remained progression-free at 33 +, 35 +, 39 + months from induction therapy. We suggest that the FE120C plus G-CSF is an effective and innovative regimen for PBSC mobilization in breast cancer patients, and high-dose CTCb therapy with PBSC support is a safe and well-tolerated treatment modality.

Adult↗
PubMed1998

Overexpression of p53 predicts shorter survival in diffuse type gastric cancer.

BACKGROUND: It has been suggested that p53 plays an important part in gastric carcinogenesis but the data remain inconclusive. METHODS: Alteration of the tumour suppressor gene p53 was prospectively investigated by immunohistochemistry in 168 primary gastric cancers. RESULTS: Positive staining, indicative of gene mutations, was detected in 34 tumours (20.2 per cent). No correlation was observed between expression of p53 and various clinicopathological factors, including age, sex, tumour site, gross type, tumour size, depth of invasion, lymph node metastases, distant metastases, and tumour node metastasis stage. However, p53 overexpression was different between intestinal and diffuse type gastric cancer. Survival analysis revealed a significant survival disadvantage of p53 expression in diffuse type gastric cancer (P=0.039) but not in the intestinal type. Multivariate analysis of all 168 patients revealed that independent predictors of recurrent disease included age, invasion depth and nodal involvement but not p53 expression. CONCLUSION: The presence of p53 overexpression may identify a subset of more aggressive tumours with a poor prognosis in diffuse type gastric cancer.

Adenocarcinoma↗
PubMed1998

Water-soluble contrast study predicts the need for early surgery in adhesive small bowel obstruction.

BACKGROUND: The optimal period of conservative treatment for adhesive small bowel obstruction remains controversial. This study sought to determine whether a 24-h abdominal radiograph after oral Urografin is a reliable indicator for operation in patients with adhesive small bowel obstruction. METHODS: One hundred and sixty-one patients who suffered from adhesive intestinal obstruction without clinical evidence of strangulation or gangrene underwent a Urografin study. Some 40 ml Urografin mixed with 40 ml distilled water was administered either orally or via a nasogastric tube to each patient. Serial plain abdominal radiographs were taken 4, 8, 16 and 24 h later. If an earlier plain radiograph showed that contrast medium had reached the ascending colon, subsequent radiographs were not taken. RESULTS: Contrast medium reached the colon within 24 h in 112 patients (70 per cent). These patients were all treated successfully with non-operative methods. Contrast medium was not observed in the colon within the first 24 h in 49 patients (30 per cent). Operation was performed in 47 of these patients and non-operative treatment was given in two. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of Urografin reaching the colon within 24 h as an indicator for non-operative treatment were 98, 100, 99, 100 and 96 per cent respectively. CONCLUSION: All patients with evidence of Urografin reaching the colon within 24 h were treated successfully with non-operative methods. The results of this prospective study suggest that patients with adhesive intestinal obstruction in whom contrast medium fails to reach the colon within 24 h should receive prompt surgical intervention.

Adult↗
PubMed1998

Accuracy of auscultation in the detection of haemopneumothorax.

OBJECTIVE: To assess the accuracy of auscultation in the detection of haemopneumothorax. DESIGN: Prospective study. SETTING: University hospital, Taiwan. PATIENTS: 148 patients with chest injuries admitted between July 1994 and August 1996. MAIN OUTCOME MEASURES: Correlation between the results of auscultation and radiographic findings in 148 patients with injuries to the chest. 83 (56%) had internal injuries, of whom 38 had pneumothoraces, 24 haemothoraces, and 21 haemopneumothoraces. RESULTS: Auscultation had a sensitivity of 84%, a specificity of 97%, an accuracy of 89% and a positive predictive value of 97% in the detection of these injuries. CONCLUSIONS: Auscultation is not as accurate as chest radiography. Chest tubes can be inserted before chest radiography in patients in whom auscultation has indicated an injury. A chest radiograph is essential in those patients with normal breath sounds to exclude a haemopneumothorax that had been missed by auscultation.

Adolescent↗
PubMed1998

Tissue plasminogen activator reduces intraperitoneal adhesion after intestinal resection in rats.

We investigated whether tissue plasminogen activator (tPA), a plasma serine protease that catalyzes the initial and rate-limiting step in fibrinolysis, inhibits postoperative intraperitoneal adhesion formation in rats. Male Wistar rats weighing 200 to 250 g underwent laparotomy with a 15-cm intestinal resection and reanastomosis; the intestinal serosa was scratched to induce adhesion formation. The rats were divided into three groups: the control group received no medication; the normal saline group received peritoneal irrigation with 6 mL normal saline intraoperatively; and the tPA group received peritoneal irrigation with 6 mL tPA solution (5 mg/L) intraoperatively. The rats were killed 7 or 14 days later. The scores (severity of adhesion, 0-3 point scale), strength, and extent of fibrous bands were recorded on the day the rats were killed. Wound strength was measured using an Instron tensionmeter immediately after the rats were killed. The concentrations of plasma tPA and plasminogen activator inhibitor (PAI)-1 and -2 were measured. The scores and strength of fibrous bands in the tPA group were lower than those in the control and saline groups whereas wound strength was similar in all groups. The plasma tPA concentration was significantly higher and the plasma PAI-1 and PAI-2 concentrations were significantly lower in the tPA group than in the control and saline groups on the 7th and 14th postoperative days. Our findings suggest that tPA can reduce the incidence of postoperative intraperitoneal adhesions without impairing wound healing.

Animals↗
PubMed1998

An early comparison between endoscopic ultrasound-guided fine-needle aspiration and mediastinoscopy for diagnosis of mediastinal malignancy.

Precise mediastinal lymph node staging is essential in non-small cell lung cancer for proper evaluation and treatment. In addition to CT, mediastinoscopy is routinely used for staging and diagnosis of mediastinal malignancy. Recently, endoscopic ultrasound (EUS) combined with fine-needle aspiration (FNA) biopsy has been used to evaluate mediastinal disease. The purpose of this study was to assess and compare mediastinoscopy with EUS/FNA in the evaluation of mediastinal masses. From August 1995 to July 1997, 21 patients with suspected mediastinal malignancy underwent cervical mediastinoscopy with biopsy. During this same period, seven patients with suspected mediastinal malignancy were evaluated using EUS/FNA. All patients were retrospectively studied. Both mediastinoscopy and EUS/FNA were highly sensitive in diagnosing mediastinal malignancy (100% and 86%, respectively). Specificity and positive predictive value were 100 per cent for both procedures. Mediastinoscopy and EUS/FNA are highly accurate methods of staging mediastinal malignancy. Mediastinoscopy provides better access to the upper and anterior mediastinum, whereas EUS/FNA can safely be used to biopsy subcarinal and posterior mediastinal masses. Mediastinoscopy and EUS/FNA target different areas of the mediastinum and may be complimentary in the evaluation of mediastinal malignancy and staging of bronchogenic carcinoma.

Adenocarcinoma↗
PubMed1998

Dopamine-dependent behavioural stimulation by non-peptide delta opioids BW373U86 and SNC 80: 1. Locomotion, rearing and stereotypies in intact rats.

The unconditioned behavioural effects of two non-peptide delta-opioid receptor agonists, BW 373U86 and SNC 80, were studied in the intact rat. BW 373U86 (0.1-2.5 mg/kg s.c.) and SNC 80 (2.5-10 mg/kg s.c.) dose-dependently elicited locomotion, rearing, stereotyped sniffing, licking and gnawing. These effects were abolished by pretreatment with the delta-opioid receptor antagonist naltrindole (5.0 mg/kg s.c.). In view of the phenomenological similarities between this syndrome and that elicited by dopamine-receptor agonists, the role played by dopamine receptors was investigated. The specific dopamine D1 receptor antagonist SCH 23390 and the specific dopamine D2/D3 receptor antagonist raclopride reduced or even abolished the behavioural stimulation induced by lower doses of BW 373U86 and SNC 80. When higher doses of BW 373U86 were used (2.5 mg/kg), however, raclopride, even at high cataleptic doses (6.0 mg/kg), only partly prevented the behavioural stimulation induced by the delta-opioid receptor agonist. The behavioural stimulation remaining after high doses of raclopride was abolished by the administration of SCH 23390. These results show that delta-opioid receptor stimulation elicits dopamine-dependent behavioural activation in the rat that depends on dopamine receptors, particularly of the D1 subtype.

Animals↗
PubMed1998

Delta-opioid ligands reverse alfentanil-induced respiratory depression but not antinociception.

Evidence suggests both opioid mu and delta receptors may participate in the regulation of respiration at different central nervous system sites. In the past, the overlapping receptor specificity of various opioid drugs has made it difficult to dissect the receptor subtype-specific activities involved in respiratory regulation. The new family of delta receptor selective agents such as cyclic[D-Pen2, 5]enkephalin, deltorphins, (+)-4-((alpha-R)-alpha-((2S,5R)-4-allyl-2, 5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N,N-diethylbenzamide, naltrindole and H-Tyr-Tic(psi)[CH2NH]Phe-Phe-OH have now made it feasible to more clearly define the role of delta receptors in respiratory control. In a series of experiments we observed that systemic infusion of rats with the highly mu receptor-specific opioid alfentanil induced antinociception and hypercapnia, and both of these effects were antagonized by the mu antagonist D-Phe-Cys-Tyr-Orn-Thr-Pen-Thr-NH2. However, peripheral administration of the delta receptor antagonist naltrindole reverses the hypercapnia but not the antinociceptive activity of alfentanil. This differential effect of naltrindole on antinociception and hypercapnia could also be produced with the delta agonist (+)-4-((alpha-R)-alpha-((2S,5R)-4-allyl-2, 5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N,N-diethylbenzamide. In addition, intracerebroventricular delivery of a number of peptide delta ligands cyclic[D-Pen2,5]enkephalin, deltorpnin II and H-Tyr-Tic(psi)[CH2NH]Phe-Phe-OH also produced the same differential reversal of hypercapnia without affecting antinociception. Thus, both the traditional delta agonists and antagonists are able to reverse the alfentanil-induced hypercapnia without affecting antinociception. The reversal of alfentanil-induced hypercapnia by these delta ligands was antagonized by a novel synthetic delta antagonist cis-4-(alpha-(4-((Z)-2-butenyl)-3, 5-dimethyl-1-piperazinyl)-3-hydroxybenzyl)-N,N-diethylbenzamide. We propose that in this experimental respiration model, the delta antagonists naltrindole and H-Tyr-Tic(psi)[CH2NH]Phe-Phe-OH behave like delta agonists with low but sufficient intrinsic activities to reverse alfentanil-induced hypercapnia in rats. The results suggest that a function of the delta receptor is to modulate or counteract the respiratory depression induced by the mu receptor.

Alfentanil↗
PubMed1997

Differential effects of gonadotropin and orthovanadate on oocyte maturation, ovulation, and prostaglandin synthesis by Rana ovarian follicles in vitro.

Effects of gonadotropin and sodium orthovanadate on oocyte maturation, ovulation, prostaglandin, and progesterone synthesis were examined during in vitro culture of Rana ovarian follicles obtained from hibernating animals. Frog pituitary homogenates (FPH, 0.05 gland/ml) effectively induced oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation (> 90%) in ovarian follicles obtained in mid-hibernation (mid-December through late January). In contrast, orthovanadate induced a limited amount (< 45%) of ovulation of some oocytes without concomitant induction of maturation during mid-hibernation. In late hibernation (February to early March), considerable spontaneous maturation and ovulation occurred in cultured ovarian follicles. During this period both FPH (0.0005-0.05 gland/ml) or orthovanadate (0.01-1 mM) treatment markedly increased the incidence of ovulation and accelerated the onset of ovulation in a dose dependent manner. When examined after 12 h of culture, few (< 5%) oocytes ovulated in response to orthovanadate had undergone GVBD whereas most (> 90%) of those ovulated in response to FPH had matured. However, the majority of oocytes ovulated (72%) within 6 h of exposure to FPH had intact GVs, indicating that GVBD is also not a prerequisite for ovulation induction in response to FPH. Orthovanadate stimulated PGF2 alpha in a dose dependent manner but failed to stimulate progesterone production whereas FPH stimulated secretion of both PGF2 alpha and progesterone. The amount and time course of PGF2 alpha secretion in response to orthovanadate were similar to results produced with FPH stimulation. Treatment of PGF2 alpha to follicles obtained in late hibernation also accelerated the ovulation of the oocytes. Taken together, the data suggest that orthovanadate enhanced ovulation of immature oocytes was mediated via enhanced PGF2 alpha production and that oocyte maturation is not essential or prerequisite for in vitro oocyte ovulation in Rana.

Animals↗
PubMed1997

Seroprevalence of Helicobacter pylori in patients with surgical peptic ulcer.

BACKGROUND: Helicobacter pylori is known as a major cofactor in ulcerogenesis. However, the role of H pylori in surgical patients with peptic ulcer and its possible influence on surgical treatment is unclear. OBJECTIVES: To determine the prevalence of H pylori infection in surgical patients with complicated peptic ulcer diseases and analyze its clinical significance. DESIGN: A prospective, controlled study. SETTING: University-affiliated hospital and tertiary care center. SUBJECTS: Two study groups: surgical group (n = 66), i.e., patients who received surgical treatment for their peptic ulcer disease), and control group (n = 377) comprising 3 subgroups: normal volunteers (NV subgroup, n = 136) and patients who required only medical treatment for duodenal ulcer (DU subgroup, n = 119) or gastric ulcer (GU subgroup, n = 122) from January 1, 1994 to June 30, 1995. METHODS: Preoperative or overnight fasting serum samples were collected, and H pylori state was assessed by serum anti-H pylori IgG. RESULTS: Seropositivity was similar between the surgical group (60.6%) and NV control subgroup (58.8%), but it was highest in the DU control subgroup (87.4%) (P < .001 compared with NV control subgroup), followed by GU control subgroup (76.2%) (P < .01 compared NV). The patients with surgical peptic ulcer who had both seropositive and seronegative results for H pylori were similar for sex, age, social status, ulcer history, associated major medical problems, use of nonsteroid anti-inflammatory drugs, ulcer location, type of surgery, and ulceration recurrence rate. Although patients who underwent elective surgery had a higher seroprevalence rate (88.9%) than those requiring emergency surgery (56.4%) and patients who were seronegative for H pylori seemed to be associated with a higher major morbidity, these results were not statistically significant. CONCLUSION: No significant association of H pylori infection and peptic ulcer was noted between patients who required surgical treatment compared with those who required only medical treatment; H pylori played only a limited role in the cause of disease in surgical patients, perhaps only in the cases complicated with stenosis or intractable ulcers. This suggests that presently adequate acid reduction procedure will still be the main objective of surgical treatment and prevention of the ulcer recurrence.

Adult↗