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Biomedical subjects

C W Lai

Publications and source records attributed to C W Lai.

At least 37 records · Page 2Linked to original sources
PubMed1998

Stimulatory effect of paeoniflorin on adenosine A-1 receptors to increase the translocation of protein kinase C (PKC) and glucose transporter (GLUT 4) in isolated rat white adipocytes.

In an attempt to understand the subcellular signals after activation of adenosine A-1 receptors, paeoniflorin was employed to incubate with rat white adipocytes in vitro. Translocation of protein kinase C (PKC) beta-subtype from cytosol to membrane was enhanced by an incubation with paeoniflorin in a concentration-dependent manner similar to that of porcine insulin. Also, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) inhibited this action of paeoniflorin in a concentration-related fashion and it markedly attenuated the action of paeoniflorin at a concentrations sufficient to block the action of adenosine. Moreover, chelerythrine inhibited the paeoniflorin-stimulated translocation of PKC in a way similar to that stimulated by porcine insulin. Subcellular inhibition is considered because stimulation of porcine insulin was not modified by DPCPX at concentrations sufficient to block adenosine A-1 receptors. Similar results were also observed in adipocytes regarding the translocation of glucose transporter (GLUT4) from cytosol to membrane. Thus, we found that paeoniflorin can activate adenosine A-1 receptors to increase the translocations of PKC and GLUT4, two major signals for glucose uptake, from cytosol to membrane of the white adipocytes in rats.

Adipocytes↗
PubMed1998

Common bile duct stones become smaller after endoscopic biliary stenting.

BACKGROUND AND STUDY AIMS: Endoscopic biliary stenting is often used for large or difficult common bile duct (CBD) stones that cannot be extracted at one session. We compared the sizes of the CBD stones after a period of stenting. PATIENTS AND METHODS: Over a 6-year period, a total of 444 patients with large CBD stones (> 2 cm diameter) or difficult CBD stones were managed in our endoscopy unit, of which 46 were treated by endoscopic stenting. Twenty-eight had second ERCP for stone removal after a median period of 63 days (range 17-1002 days). The largest diameter of the stones and the CBD (after correction of magnification) before and after stenting were compared using the Wilcoxon signed test. RESULTS: Before stenting the largest diameters of CBD stones were 11-46 mm (mean 24.9 mm) and decreased to 5-46 mm (mean 20.1 mm) after stenting. The difference in stone sizes was statistically significant although the CBD diameter pre- and post-stenting was not significantly different. The reduction in stone sizes was not significantly correlated with the duration of stenting. CONCLUSION: CBD stones became smaller after stenting. As the difficulty of stone extraction increases with stone size, a period of stenting may make subsequent removal easier for patients with large or difficult CBD stones.

Aged↗
PubMed1997

Randomised comparison between adrenaline injection alone and adrenaline injection plus heat probe treatment for actively bleeding ulcers.

OBJECTIVE: To compare endoscopic adrenaline injection alone and adrenaline injection plus heat probe for the treatment of actively bleeding peptic ulcers. DESIGN: Randomised prospective study of patients admitted with actively bleeding peptic ulcers. SETTING: One university hospital. SUBJECTS: 276 patients with actively bleeding ulcers detected by endoscopy within 24 hours of admission: 136 patients were randomised to endoscopic adrenaline injection alone and 140 to adrenaline injection plus heat probe treatment. MAIN OUTCOME MEASURES: Initial endoscopic haemostasis; clinical rebleeding; requirement for operation; requirement for blood transfusion; hospital stay, ulcer healing at four weeks; and mortality in hospital. RESULTS: Initial haemostasis was achieved in 131/134 patients (98%) who received adrenaline injection alone and 135/136 patients (99%) who received additional heat probe treatment (P = 0.33). Outcome as measured by clinical rebleeding (12 v 5), requirement for emergency operation (14 v 8), blood transfusion (2 v 3 units), hospital stay (4 v 4 days), ulcer healing at four weeks (79.1% v 74%), and in hospital mortality (7 v 8) were not significantly different in the two groups. In the subgroup of patients with spurting haemorrhage 8/27 (29.6%; 14.5% to 50.3%) patients from the adrenaline injection alone group and 2/31 (6.5%; 1.1% to 22.9%) patients from the dual treatment group required operative intervention. The relative risk of this was lower in the dual treatment group (0.17; 0.03 to 0.87). Hospital stay was significantly shorter in the dual treatment group than the adrenaline injection alone group (4 v 6 days, P = 0.01). CONCLUSION: The addition of heat probe treatment after endoscopic adrenaline injection confers an advantage in ulcers with spurting haemorrhage.

Adult↗
PubMed1997

Antihyperglycemic effects of paeoniflorin and 8-debenzoylpaeoniflorin, glucosides from the root of Paeonia lactiflora.

Paeoniflorin and 8-debenzoylpaeoniflorin were isolated from the dried root of Paeonia lactiflora Pall. (Ranunculaceae). They produced a significant blood sugar lowering effect in streptozotocin-treated rats and had a maximum effect at 25 min after treatment. This hypoglycemic action was also observed in normoglycemic rats only at 1 mg/kg. The antihyperglycemic activity of 8-debenzoylpaeoniflorin seems lower than that of paeoniflorin. Plasma insulin was not changed in paeoniflorin-treated normoglycemic rats indicating an insulin-independent action. Also, this glucoside reduced the elevation of blood sugar in glucose challenged rats. Increase of glucose utilization by paeoniflorin can thus be considered. There are no previous data showing the hypoglycemic activity of paeoniflorin and/or 8-debenzoylpaeoniflorin in rats.

Animals↗
PubMed1996

Comparison of isoproterenol with BRL37344 in activation of beta 3-adrenoceptors to inhibit the uptake of [14C]deoxy-D-glucose and translocation of glucose transporter (GLUT4) to membrane fraction in rat adipocytes.

In an attempt to understand the role of beta 3-adrenoceptors in the regulation of glucose uptake, the effect of isoproterenol was compared with BRL37344 in isolated white adipocytes of the rat using [14C]deoxy-D-glucose as an indicator. In the presence of BRL37344, the specific agonist of beta 3-adrenoceptors, spontaneous uptake of [14C]deoxy-D-glucose (glucose uptake) into adipocytes was markedly attenuated. Similar concentration-dependent inhibition of glucose uptake was also observed in the samples treated with isoproterenol, an agonist for all kinds of beta-adrenoceptors. Action of BRL37344 was blocked by propranolol at concentrations sufficient to abolish the activity of isoproterenol. Pindolol reversed BRL37344-induced inhibition more effectively than propranolol. Moreover, unlike the action of isoproterenol, BRL37344 did not modify the insulin-stimulated glucose uptake. Translocation of glucose transporter (GLUT4) from cytosol to membrane stimulated with insulin was reduced by isoproterenol but not by BRL37344. Combination with the findings that isoproterenol prolonged the time for insulin to reach maximum stimulation of glucose uptake, leads to the conclusion that delay of insulin action by isoproterenol can be considered as one of the mechanisms for this inhibition. The results obtained suggest that BRL37344 decreased the spontaneous uptake of glucose via an activation of beta 3-adrenoceptors while the insulin stimulated glucose uptake was inhibited by isoproterenol but not by BRL37344.

Adipocytes↗
PubMed1996

Selective use of preoperative endoscopic retrograde cholangiopancreatography in laparoscopic cholecystectomy.

BACKGROUND: The management of possible common bile duct (CBD) stones in patients scheduled for laparoscopic cholecystectomy remains controversial. METHODS: Prospective evaluation of 609 patients who underwent laparoscopic cholecystectomy was carried out in relation to the use of selective preoperative ERCP for detection of common duct stones. Preoperative ERCP was performed if there is or has been (1) cholangitis, biliary pancreatitis, or jaundice; (2) abnormal serum liver tests or (3) ultrasonogram showing a dilated CBD or ductal stones. RESULTS: A total of 139 patients underwent preoperative ERCP, and cannulation of CBD was successful in 133 patients (96%). CBD stones were found in 60 patients (45%) and extracted after sphincterotomy. High prevalence of CBD stones was noted in patients with acute cholangitis and CBD stones on ultrasonogram. There were six endoscopic sphincterotomy-related complications (complication rate, 4.5%): bleeding (2), pancreatitis (3), retroduodenal perforation (1). No patient required surgery as the result of a complication. The prediction of the occurrence of ductal stones was further analyzed using stepwise logistic regression. Acute cholangitis and CBD stones on ultrasonogram were shown to be independent significant risk factors with odds ratios of 8.9 and 13.5, respectively. CONCLUSIONS: With selective preoperative ERCP, suspected CBD stones can be identified and removed prior to laparoscopic cholecystectomy.

Adult↗
PubMed1995

Survey of public awareness, understanding, and attitudes toward epilepsy in Taiwan.

A survey of public awareness and understanding of and attitudes toward epilepsy was made in Taipei City and Chin-San Village, Taiwan in 1992. In a population sample of 2,610 adults, 87% had read or heard about epilepsy, 70% knew someone who had epilepsy, 56% had seen someone having a seizure, 18% would object to having their children associated with persons with epilepsy, 72% would object to having their children marry a person with epilepsy, 31% believed that epileptic persons should not be employed in jobs as other persons are, 7% believed that epilepsy was a form of insanity, 34% did not know the cause of epilepsy, 13% did not know what an epileptic attack was like, and 18% did not know what to recommend if their friends or relatives had epilepsy. Youth, higher education, and upper levels of employment were correlated with answers that were more favorable concerning epilepsy in all survey questions except for the question regarding marriage, for which the reverse was noted. The attitudes toward epilepsy disclosed by this study were more favorable than those detected in a similar survey conducted in Henan Province, China. The comparison suggests that the exposure to Western culture and socioeconomic system in Taiwan might have helped reduce the discrimination against epilepsy.

Age Factors↗
PubMed1993

Octreotide infusion or emergency sclerotherapy for variceal haemorrhage.

To compare octreotide with injection sclerotherapy in the treatment of acute variceal haemorrhage, patients admitted with gastrointestinal bleeding and oesophageal varices confirmed by endoscopy were randomised to receive either emergency sclerotherapy with 3% sodium tetradecyl sulphate or octreotide (50 micrograms intravenous bolus plus 50 micrograms per h intravenous infusion for 48 h). At the end of the study period (48 h), the octreotide group also had sclerotherapy to obliterate the varices. 100 patients were recruited. Demographic features including the aetiology of portal hypertension and the Child-Pugh's grading of the two groups were similar. Bleeding was initially controlled in 90% of patients by emergency sclerotherapy and in 84% by octreotide infusion (95% confidence interval 0-19.5, p = 0.55). There were no significant differences between the two groups in early (within 48 h of randomisation) rebleeding (16% vs 14%), blood transfusion (3 units vs 3.5), hospital stay (5 days vs 6 days), or hospital mortality (27% vs 20%). No notable side-effects were associated with octreotide. We conclude that octreotide infusion and emergency sclerotherapy are equally effective in controlling variceal haemorrhage.

Adolescent↗
PubMed1993

Basilar artery occlusion following yoga exercise: a case report.

Basilar artery occlusion developed in a 34 year old woman 2 months after adopting unusual neck postures during yoga practice. On angiography, her basilar artery was filled with intraluminal clot while the vertebral arteries were normal. We postulate that a severe reduction in blood flow and possibly an intimal tear triggered thrombosis of the vertebral artery and that the final stroke mechanism was artery-to-artery embolism.

Adult↗
PubMed1992

Effect of biliary obstruction on the hepatic excretion of imipenem-cilastatin.

The biliary excretion of imipenem-cilastatin studied by endoscopic cannulation of the common bile duct in patients with complete obstruction and in a group without obstruction showed that despite a 24-h prophylaxis, the bile obtained from patients with obstruction immediately after cannulation contained neither imipenem nor cilastatin, while there were 2 and 5% of peak concentrations in serum for imipenem and cilastatin, respectively, in the bile from patients without obstruction. Biliary excretion of both compounds increased rapidly after decompression, reaching a maximum of 15% of peak levels in serum within 2 h. Twenty-four hours after drainage, the biliary excretion of the drugs further improved. We conclude that since biliary obstruction impairs excretion of antibiotics, drainage is necessary for the control of sepsis in obstructed cholangitis.

Adult↗
PubMed1992

Common bile duct stones: a cause of chronic salmonellosis.

A chronic carrier state of Salmonella spp is present in 0.15% of the population, and is believed to be related to the presence of a diseased gallbladder. We present a patient with common bile duct (CBD) stones, whose bile cultures repeatedly indicated Salmonella typhi, despite an adequate course of antibiotic treatment. The carrier state was abolished after removal of the CBD stones 4 months later. The chronic carrier state may be related to biofilm formation on the surface of the CBD stones. The removal of the biliary stones, which are the most likely reservoir for Salmonella spp, may be a crucial step in eradication of the carrier state.

Aged↗
PubMed1990

Epilepsy, myasthenia gravis, and effect of plasmapheresis on antiepileptic drug concentrations.

A 28-year-old woman developed complex partial seizures at the age of 17 years and was treated with phenytoin sodium. Five years later she developed myasthenia gravis, and phenytoin was replaced by valproic acid and phenobarbital. She required plasmapheresis (PP). During one course of PP, total and unbound concentrations of valproic acid and phenobarbital were measured in serum sampled before, during, and after PP and in plasma removed by PP. It was determined that the magnitude of loss of valproic acid or phenobarbital by PP was small, and the changes of unbound/total ratio did not reach clinical importance.

Adult↗
PubMed1989

Clinical and electrophysiological responses to dietary challenge in migraineurs.

Thirty eight patients with a history of diet-induced migraine were studied with recording of clinical responses, electroencephalography in resting state, in response to photic stimulation, and to hyperventilation and visual evoked potentials. Tests were carried out on an initial baseline day and on a second day, after challenge with chocolate, red wine, cheese, and fasting. Lateralized headache occurred in sixteen subjects (42%), four with scintillating scotomata. Electroencephalograms were abnormal on Day 1 and/or Day 2 in twelve subjects (32%), most abnormalities being non-specific slow waves. In three cases there were paroxysmal features. Electroencephalographic response to hyperventilation was calibrated and was found to be exaggerated in eight subjects (21%) on either Day 1 or Day 2; such response was not related to the occurrence of a headache. Photic simulation showed high frequency driving response (so called "H" response) in all 16 individuals who developed headache but in only 14 out of 22 (64%) who did not (p less than 0.01). Pattern reversal visual evoked responses were normal and failed to show any difference in latency or amplitude between headache responders and non-responders.

Adolescent↗
PubMed1989

Takayasu arteritis presenting as retinal and vertebrobasilar ischemia.

A young woman presented with a 4-month history of retinal and vertebrobasilar ischemia. Angiography demonstrated narrowing of major branches of the aortic arch. Intractable, severe retroorbital pain of the right eye developed after a middle cerebral artery stroke. During 4 weeks of aggressive immunosuppressive therapy including IV high dose bolus corticosteroids and pulse cyclophosphamide, her neurologic deficit improved transiently, but her retroorbital pain persisted. She died of staphylococcal sepsis and pneumonia. An autopsy demonstrated thrombotic or fibrous occlusion, with minimal inflammation, of extracranial arteries.

Adult↗
PubMed1988

Electroencephalography in herpes simplex encephalitis.

The EEG in the acute stage of herpes simplex encephalitis (HSE) can show a variety of abnormalities, including uni- or bilateral periodic sharp waves or attenuation of amplitude, focal or generalized slow waves or epileptiform discharges, or electrical seizures. No specific EEG patterns are pathognomonic for HSE, but a focal or lateralized EEG abnormality in the presence of encephalitis is highly suspicious of HSE. In the acute stage, EEG appears to be more sensitive than computerized tomography or radioisotope brain scanning. The EEG findings tend to differ in the course of illness, and the periodic discharges occur only during the acute stage. The EEG findings in either the acute stage or long-term follow-up do not predict the chance of survival or severity of disability, and EEG changes appear to lag behind the clinical changes. EEG results can become normal in both adults and neonates when the acute stage is over.

Electroencephalography↗