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Biomedical subjects

M F Chen

Publications and source records attributed to M F Chen.

At least 289 records · Page 16Linked to original sources
PubMed1990

The effect of endotoxin on 1,2-dimethylhydrazine-induced colonic tumors in rats.

The effect of endotoxin on colon tumors was studied in male Sprague-Dawley rats. Colon tumors were induced in weanling rats by the administration of 20 weekly subcutaneous injections of 1,2-dimethylhydrazine (DMH). When colon tumors were detected by colonoscopy in 80% of the rats around week 24 after DMH injection, the animals were divided randomly into two groups. One group served as the control. The other group received six endotoxin (Escherichia coli) treatments every fifth day. The first dose was 50 micrograms/100 g (intraperitoneally); the remaining doses were 100 micrograms/100 g (subcutaneously). Rats were killed 2 weeks after the last endotoxin injection. Endotoxin treatments resulted in larger colon tumors. The median tumor size was 71 mm2 for endotoxin-treated and 31 mm2 for untreated rats (P less than 0.02). Endotoxin treatments also resulted in a significantly higher incidence (P less than 0.05) of ulcer development in the small intestine, that is 47% in the endotoxin-treated versus 23% in the untreated rats. After a single subcutaneous injection of endotoxin (100 micrograms/100 g), the colon mucosal reduced glutathione (GSH) level was raised by 21% at 16 hours, reached a peak on day 2, then decreased to baseline by day 4. The increased GSH level in the colon mucosa was maintained up to the third endotoxin injection. By the fifth injection, no increase in the GSH level was observed. These results suggest that the growth of colon tumors in rats induced by DMH could be enhanced by endotoxin treatments. The enhanced tumor growth may be due to an increase in the colon GSH level and/or other mediators released by macrophages as a result of endotoxin treatments.

1,2-Dimethylhydrazine↗
PubMed1990

Aminopterin-like syndrome sine aminopterin associated with translocation involving chromosomes 5 and 10.

We studied a baby born with physical features suggestive of the aminopterin syndrome, but without exposure of the mother to aminopterin during pregnancy. G-banded chromosomes from peripheral blood lymphocytes had a normal 46,XX pattern. However, in 50 skin fibroblasts there was a normal female karyotype in 5 cells and 45 cells showed an apparently balanced reciprocal translocation involving the long arm of chromosome 5 (band q35) and the long arm of chromosome 10 (band q22). The relation of this mosaicism to the abnormal phenotype is unclear.

Abnormalities, Multiple↗
PubMed1990

Percutaneous transhepatic cholangioscopic lithotripsy.

Since 1983, 14 patients with intrahepatic and common bile duct stones have undergone percutaneous transhepatic cholangioscopic lithotripsy because the stones were too large to be removed using ordinary percutaneous transhepatic cholangioscopy. Stones were completely fragmented in seven cases (six with intrahepatic stones and one with common bile duct stone) and partially disrupted in five cases with intrahepatic stones. Intrahepatic duct angulation and stricture was the factor most often responsible for failure. All the disintegrated stones were removed by subsequent transhepatic cholangioscopy. Amongst the seven patients with complete stone fragmentation, six stones were found with electrohydraulic shock-wave lithotripsy and one with NdYAG laser lithotripsy. Complications of percutaneous transhepatic cholangioscopic lithotripsy using electrohydraulic shock waves were found in three cases, two had transient haemobilia and one had fever and chills after the procedures. They all recovered by conservative treatment. NdYAG laser treatment was expensive, time consuming and inconvenient to use. Percutaneous transhepatic cholangioscopic lithotripsy by using electrohydraulic shock wave is an effective and safe method to fragment biliary stones and to facilitate their removal.

Adult↗
PubMed1990

Effect of DL-buthionine-S,R-sulfoximine on 1,2-dimethyl-hydrazine-induced colonic tumors in rats.

The effect of DL-buthionine-S,R-sulfoximine (BSO), a specific inhibitor of glutathione biosynthesis, on colon tumor development was studied in rats. Weanling male Sprague-Dawley rats were randomly assigned to one of three groups following a week of adaptation. Group 1 rats received BSO (4.5 mM) daily in the drinking water one week before 1,2-dimethylhydrazine (DMH) injections and continued to receive BSO daily until sacrificed; group 2 rats received BSO (4.5 mM) after the last DMH injection, and continued to receive BSO daily until sacrificed; group 3 rats did not receive BSO. All experimental rats received 20 weekly subcutaneous injections of DMH (20 mg/kg body wt.) for colon tumor induction. The tumor incidence was lower in group 1 (54%) than in group 2 (97%) or group 3 (96%). The median tumor size is significantly smaller in group 1 (11 mm2) than group 3 (46 mm2). The group 2 had the largest median tumor size (65 mm2).

1,2-Dimethylhydrazine↗
PubMed1990

Effect of ascorbic acid on plasma alcohol clearance.

The effects of short-term and long-term ascorbic acid supplements on plasma alcohol clearance were studied in 13 clinically healthy male subjects. Two dose levels of alcohol, 0.5 and 0.8 g/kg body weight, were used. Blood samples were taken at zero time, 0.5 hours, then hourly up to 6 hours after alcohol consumption for the measurement of plasma alcohol and ascorbic acid levels, red-cell reduced glutathione level, and plasma alanine aminotransferase activity. At both dosages of alcohol, short-term as well as long-term pretreatment with ascorbic acid significantly enhanced the clearance of plasma alcohol. Although long-term ascorbic acid pretreatment resulted in better alcohol clearance, no significant difference in alcohol clearance was found between short-term and long-term ascorbic acid pretreatment. The two dose levels of alcohol had no significant effect on the red-cell reduced glutathione concentration or plasma alanine aminotransferase activity.

Adult↗
PubMed1990

The pharmacological and pathological studies on Taiwan folk medicine (III): The effects of bupleurum kaoi and cultivated bupleurum falcatum var. komarowi.

The protective effects of water extract from roots of Bupleurum kaoi Liu, Chao et Chuang and Bupleurum flacatum L. var. Komarowi Koso-Polj on CCl4-induced hepatoxicity have been investigated. Both B. kaoi (p less than 0.05) and B. falcatum var. komarowi (p less than 0.01) possessed more marked anti-hepatotoxic pharmacological effects than Bupleurum chinense DC., the typical strain widely used in Taiwan. The pathological improvement from treatment by means of the three drugs to alleviate CCl4-induced hepatic toxicity was estimated using morphological changes of hepatocytes, reduction of inflammatory cells infiltration and liver function tests.

Alanine Transaminase↗
PubMed1990

Effects of intravenous fat emulsion on respiratory failure.

The effects of intravenous fat emulsion on ventilated normal, diseased or distressed lungs were studied. Forty-eight patients with different types of respiratory failure were divided into four groups. Group A was composed of the patients with a normal lung condition; group B, patients with infectious pulmonary condition and respiratory failure; group C, patients with COPD and respiratory failure; and, group D was composed of the patients with ARDS due to various causes. Five hundred milliliters of 10 percent fat emulsion was infused within 4 h as partial parenteral nutritional support. We concluded that intravenous fat infusion decreased PaO2/FIO2 and increased P(A-a)O2 and intrapulmonary shunt in the patients with ARDS, while it had little effect on the patients with infectious pulmonary disease or COPD. The infusion of fat emulsion had positive effects on the patients with normal lung condition with increased PaO2/FIO2 and decreased P(A-a)O2 and shunt.

Bicarbonates↗
PubMed1990

Effect of glycyrrhizin on the pharmacokinetics of prednisolone following low dosage of prednisolone hemisuccinate.

We investigated the pharmacokinetics of prednisolone (PSL) in six healthy men, with or without glycyrrhizin (GL), to confirm whether GL influences the metabolism of PSL in humans. Each subject received an intravenous administration of 0.096 mg/kg of prednisolone hemisuccinate (PSL-HS, equivalent to 0.075 mg/kg of PSL), with or without 200 mg of GL. Blood samples were taken from a peripheral vein at 5, 10, 15, 30 and 45 min, and 1, 1.5, 2, 3, 4, 6, 8, 10, 12 and 24 h after PSL-HS infusion. The concentration of total PSL in the plasma was analyzed by high-performance liquid chromatography, and the free PSL was measured by an isocolloidosmolar equilibrium dialysis method. The pharmacokinetic parameters of PSL were determined, using noncompartmental analysis. GL was found to increase significantly the concentration of total PSL at 6, 8 h, and of free PSL at 4, 6, and 8 h after PSL-HS infusion. GL was also found to modify the pharmacokinetics of PSL. After the administration of GL, the area under the curve (AUC) increased, total plasma clearance (CL) decreased, and the mean residence time (MRT) was prolonged. However, only those of AUC, CL, and MRT of free PSL were significantly different. The volume of distribution at a steady-state (Vdss) of both total and free PSL showed no evident change. This suggests that GL increases the plasma PSL concentrations by inhibiting the metabolism of PSL and that it potentiates pharmacological effects of PSL.

Adult↗
PubMed1990

Subcutaneous injection of 99mTc pertechnetate at acupuncture points K-3 and B-60.

The acupuncture points are known to be morphologically related to the nerves and vessels. Yet the physiological role of blood vessels in the formation of acupuncture points remains unknown. With subcutaneous injection of 99mTc pertechnetate at the acupuncture points K-3 and B-60 and with intra-acupuncture point injection of 99mTc pertechnetate at K-3 and B-60, a lower-limb venography like what was obtained by intravenous injection of 99mTc macroaggregated albumin was demonstrated in the present study. It seems that some acupuncture points do play a role in drainage of tissue fluid from soft tissue into the veins.

Acupuncture Points↗
PubMed1990

The coronary hemodynamics and left ventricular function in patients with compensated hypertension.

In this study, we tried to characterize the changes in left ventricular (LV) function and coronary hemodynamics in patients with compensated hypertension (HT) who were free from coronary artery disease. The study group consisted of 10 men with compensated essential HT at ages 48-65 years (mean = 58). The durations of HT history for the various patients ranged from 5 to 14 years. Mean arterial pressure (MAP) was 122 +/- 2 mmHg at the time of study. The control group was composed of 8 men with mild mitral valve prolapse. They were studied because of chest pain with no demonstratable pathological conditions. Their ages ranged from 39 to 65 years (mean = 57). The MAP for controls was 86 +/- 3 mmHg. All patients in both groups underwent routine cardiac catheterization, coronary arteriography, and measurements of the coronary sinus (CS) and great cardiac vein (GCV) blood flows. Left ventricular muscle mass (LVMM), coronary resistance and coronary reserve were also derived from the hemodynamic study. There was a significant difference in the LVMM index between the study patients (114.9 g/m2) and the control subjects (96.8 g/m2, p less than 0.001). The LV function of the patients in the study group was essentially normal, but the following parameters were significantly different from those of the control subjects: cardiac index, stroke volume index, and dp/dtmax. There was a good correlation between repeated measurements of both the CS and GCV blood flows (r = 0.97 for both).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Clinical experience in 20 hepatic resections for peripheral cholangiocarcinoma.

During the 10-year period from 1978 to 1987, hepatic resections were performed on 20 patients with peripheral cholangiocarcinoma (PCC). Nine of these patients were men and 11 were women (mean age, 48.5 years). Among them, 80% had intrahepatic stones with recurrent cholangitis. The 20 patients were subdivided into the following three groups: Group I (12 patients with surgery for PCC); Group II (4 patients with surgery for chronic cholangitis [but the final pathologic diagnosis confirmed PCC]); and Group III (4 patients with surgery for space-occupying liver lesions). No early postoperative mortality was noticed. The few complications that occurred were related to surgery for hepatolithiasis. Postoperative wound infection was the most common complication. The overall mean survival time was 20.5 months. Four patients survived for more than 3 years; one was even alive for more than 5 years after surgery.

Adenoma, Bile Duct↗
PubMed1989

[The treatment of esophagojejunal anastomotic stricture after total gastrectomy].

From December 1983 through December 1988, 200 cases of total gastrectomy were performed in Chang Gung Memorial Hospital. The esophagojejunostomy was performed with EEA staplers in 196 cases, and with hand suture in 4 cases. Twelve cases developed anastomotic stricture after the operation. All of these 12 anastomoses were done with EEA 28 mm staplers. Four of the 12 patients received no further treatment either because the symptoms were mild or because of development of carcinomatosis. Six patients received endoscopic YAG laser treatment, only 2 had good results. Four Patients received balloon dilatation, 2 of them had good results, 4 patients received surgical intervention after failure of the balloon dilatation or YAG laser treatment. Of the 4 patients who underwent surgery, the thoracoabdominal approach was used in 3, and a thoracotomy in 1. Three patients received side to side esophagojejunostomy to bypass the stricture site. In the remaining patient, stricture was excised and a new end to end anastomosis was done with hand sutures. All of these 4 patients had good results after the operation. There are many possible mechanisms of the development of anastomotic stricture. Anastomotic leakage, technical error, lack of mucosa-to-mucosa apposition, size of the EEA stapler and tissue ischemia all have been regarded as the possible causes of anastomotic stricture. Once the esophagojejunal anastomosis stricture occurs, treatment should be done to relieve dysphagia. From the results of our patients, endoscopic YAG laser is not a satisfactory treatment for anastomotic stricture.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Hepatic resection in 120 patients with hepatocellular carcinoma.

During the 11-year period from 1977 through 1987, hepatic resections were carried out in 120 patients with hepatocellular carcinoma (HCC). Twenty-five had HCCs smaller than 5 cm in diameter. There were 97 male and 23 female patients, with an average age of 51.5 years. Among them, 45.8% had liver cirrhosis and 80.8% were positive for hepatitis B surface antigen. Fourteen with ruptured HCCs underwent hepatic resection to control the intra-abdominal hemorrhage. Operative mortality within one month after surgery was 4.1%. The postoperative course was complicated by pleural effusion in 5.8%, subphrenic abscess in 2.5%, postoperative bleeding in 1.6%, hepatic failure in 1.6%, and bile leakage in 0.8% of the patients. The overall five-year survival rate in this series was 25.9%, while survival for the last five years was better (42.3% vs 11.9% for patients treated between 1977 and 1982). The cumulative survival rate had no relation to tumor rupture or liver cirrhosis. The group of patients with smaller tumors (diameter, less than 5 cm) or without vascular invasion by tumor had better survival.

Adolescent↗
PubMed1989

Pharmacokinetic and pharmacodynamic comparison of conventional and controlled release formulations of metoprolol [correction of motoprolol] in healthy Chinese subjects.

A double-blind, crossover comparison of the pharmacokinetics and pharmacodynamics of controlled-release metoprolol (CR) 100 mg and 200 mg, metoprolol plain tablet 100 mg, metoprolol Durules 200 mg, and placebo was carried out in 10 healthy Chinese subjects. Standardized treadmill exercise tests according to the Bruce protocol were performed at a steady state of medication, before and 2, 6, 12, and 24 hours after the dose, and multiple blood samples were collected for determination of the metoprolol concentration. The plasma metoprolol levels over 24 hours were more uniform after metoprolol CR than Durules and the plain tablet. The mean peak concentrations for CR 100 mg, 200 mg, Durules, and the plain tablets were 231, 426, 790, and 1105 nmol/l, respectively. The corresponding fluctuation incides were 1.1, 1.5, 2.2, and 5.0. The effects on exercise heart rate (EHR) were investigated at steady state. Metoprolol CR produced more even reduction in EHR over 24 hours than Durules and plain tablets. All four treatments gave similar maximal reduction in EHR of about 20% at 2 hours after the dose. In conclusion, once daily metoprolol CR showed almost even blood levels and provided relatively constant levels of beta1 blockade over 24 hours in healthy Chinese subjects.

Adult↗
PubMed1989

Relationship between coronary artery size and ventricular hypertrophy.

The relationship between coronary blood flow and ventricular hypertrophy has been studied in animal models. But, this relationship in the human body is scarcely evaluated. In this study we measured coronary arterial sizes by coronary arteriograms and correlated them with ventricular hypertrophy. Patients who underwent cardiac catheterization and coronary arteriography and showed no significant coronary arterial lesions were included in this study. There were 131 patients, 75 men and 56 women, with a mean age of 53 +/- 10 years (S.D.). After evaluation with electrocardiograms, echocardiograms and left ventriculograms these patients were divided into 4 groups: (1) the non-hypertrophy (NVH) group, 50 cases; (2) the left ventricular hypertrophy (LVH) group, 38 cases; (3) the right ventricular hypertrophy (RVH) group, 23 cases; and (4) the biventricular hypertrophy (BVH) group, 20 cases. The proximal portion of the 3 major coronary arteries and the left main stem were measured from coronary arteriograms with the catheter tip as a size reference. The results showed that the left main stem was larger than the 3 major coronary arteries in the NVH, LVH and BVH groups. But in the RVH group, the left main stem was not significantly larger than the right coronary artery. In all 4 groups the left circumflex coronary artery was the smallest while the left anterior descending coronary artery and the right coronary artery were similar in size. Patients with LVH showed dilatation of all 3 left coronary measurements (left main stem, left anterior descending coronary artery and left circumflex coronary artery) as compared with the NVH patients and the RVH patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗