The biochemistry of an acetylcholine receptor.
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Acetylcholine↗
Biomedical subjects
Y Chao
Publications and source records attributed to Y Chao.
How I have striven to be a revolutionary doctor boundlessly loyal to Chairman Mao.
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China↗
Serum, insulin and phorbol esters stimulate rRNA and tRNA gene expression in both dividing and nondividing Drosophila cells.
The expression of genes that code for the large ribosomal RNAs (rRNAs) and tRNAs can be regulated by calcium, serum, insulin and a tumor-promoting phorbol ester, TPA. These effectors can rapidly alter rRNA and tRNA synthesis in dividing and nondividing Drosophila cells. In an in vitro assay system of the nondividing cells of the male accessory glands, calcium, insulin and TPA were shown to increase both rRNA and tRNA synthesis. Exposure of actively dividing Drosophila culture cells to differing serum concentrations or TPA also altered rRNA and tRNA synthesis. Nuclear run-on assays demonstrate that the exposure of these cells to increased serum concentrations coordinately alters RNA polymerase I loading on both 18S and 28S rDNA. These data indicate that calcium, growth factors and a tumor-promoter each can signal changes in ribosomal and tRNA gene expression.
Animals↗
Effect of addition of water-soluble polysaccharides on bacterial cellulose production in a 50-L airlift reactor.
Bacterial cellulose (BC) production was carried out in a batch cultivation of Acetobacter xylinum in a 50-L internal loop airlift reactor by addition of water-soluble polysaccharides into the medium. When 0.1% (w/w) agar was added, BC production reached 8.7 g/L compared with 6.3 g/L in the control, and duration of the cultivation period to reach the maximum concentration of BC was almost half of that without addition of polysaccharides. During cultivation, BC was formed into pellets whose size was smaller when the productivity of BC was higher, indicating that increase in the relative viscosity by addition of polysaccharides hindered formation of large clumps of BC and increase in the volumetric oxygen transfer coefficient at high flow rate led to increase in BC productivity.
Acetobacter↗
A randomized controlled study of low-dose and high-dose terlipressin in the control of acute oesophageal variceal haemorrhage.
A randomized controlled trial was designed to investigate whether a high dose of terlipressin could control acute variceal haemorrhage more effectively than a low dose of terlipressin. Forty cirrhotic patients with bleeding oesophageal varices were included, with low-dose terlipressin in 21 patients and high-dose terlipressin in 19 patients. The two groups of patients were similarly matched for all parameters on admission. High-dose terlipressin (84%) seemed to be more effective in the initial control of bleeding than low-dose terlipressin (67%); however this difference was not significant. Complete control of bleeding during 24 h of drug infusion was achieved in 53% of patients receiving high-dose terlipressin and in 48% of those treated with low-dose terlipressin (P greater than 0.05). There were no major complications in either group. Mortality in relation to variceal bleeding and transfusion requirements were similar in the two groups. This study shows that high dose terlipressin is not superior to low dose terlipressin in acute variceal bleeding.
Aged↗
C-reactive protein and lactate dehydrogenase isoenzymes in the assessment of the prognosis of acute pancreatitis.
The value of serum C-reactive protein, lactate dehydrogenase isoenzymes and erythrocyte sedimentation rate in predicting the outcome of acute pancreatitis was evaluated for 57 episodes in 54 patients. Serum C-reactive protein levels on day 2, 4 and 7 after admission were significantly higher in 19 episodes of severe attacks than in 38 episodes of mild attacks (13.71 +/- 9.68, 9.00 +/- 7.54, 6.02 +/- 3.83 vs 4.78 +/- 3.91, 3.30 +/- 3.61, 1.43 +/- 2.08 mg/dL; P less than 0.0001, P less than 0.005, P less than 0.0001, respectively). The sensitivity, specificity and accuracy of predicting a severe attack were 94, 76 and 82% using C-reactive protein greater than or equal to 8 mg/dL on day 2; 67, 92 and 84% using C-reactive protein greater than or equal to 5 mg/dL on day 7; and 59, 76 and 70% using Ranson's criteria greater than or equal to 3. Increases in LDH-4 and LDH-5 isoenzymes were found in both groups, with LDH-4 being slightly higher in severe attacks than in mild attacks. There was no significant difference of erythrocyte sedimentation rate between both groups. When compared with Ranson's criteria, lactate dehydrogenase isoenzymes and erythrocyte sedimentation rate, C-reactive protein is more valuable in the early assessment of the severity of acute pancreatitis.
Acute Disease↗
Changes of hepatic and systemic haemodynamics following somatostatin administration in patients with hepatitis B-related cirrhosis.
Somatostatin has been used to effectively control acute variceal haemorrhage, with conjectured mechanisms on portal hypertension. We, therefore, evaluated the effects of somatostatin on hepatic and systemic haemodynamics in 15 patients with hepatitis B-related cirrhosis and portal hypertension. All patients received an intravenous, continuous infusion of somatostatin 250 micrograms/h, following a bolus injection of 250 micrograms. In systemic haemodynamics, the mean arterial pressure (MAP) increased (P < 0.05), associated with a reflex bradycardia within 3 min following bolus injections, compared with basal values. The right atrial pressure, pulmonary capillary wedge pressure, inferior vena cava pressure, cardiac index, and systemic vascular resistance remained unaffected after drug infusion. In hepatic haemodynamics, the wedge hepatic vein pressure remained unchanged after drug administration. However, there was an increase in free hepatic vein pressure (FHVP; P < 0.05), and a trend toward a decrease in the hepatic vein pressure gradient (HVPG; P = 0.063), within 3 min after bolus injection. Furthermore, the hepatic blood flow decreased significantly at 10 and 30 min after somatostatin infusion (P < 0.05). The effective sinusoidal perfusion assessed by indocyanine green infusion also decreased progressively at 10 min (P = 0.057) and 30 min (P < 0.05). We concluded that somatostatin, at the dose used in this study, caused a transient and bolus-related vasoconstrictive effect, resulting in increases in MAP and FHVP, a decrease in heart rate, and a trend toward lower HVPG. In addition, somatostatin reduced the hepatic blood flow and effective sinusoidal perfusion which may be hazardous to cirrhotic patients during variceal haemorrhage.
Female↗
Measurement of intravariceal pressure by fine needle direct puncture in hepatitis B surface antigen-positive cirrhotic patients: the effect of vasopressin.
The pressure of oesophageal varices was determined by fine needle direct puncture in 19 patients with hepatitis B surface antigen (HBsAg)-positive cirrhosis after the first episode of variceal bleeding before endoscopic sclerotherapy. Both the stability and reliability of the measurement of intravariceal pressure by fine needle puncture were confirmed. Seven patients received intravenous 1 mL normal saline. Intravariceal pressure did not change before and after injection of normal saline (16.3 +/- 4.0 vs 16.0 +/- 4.0 mmHg, P > 0.05). Twelve patients received intravenous 1 units vasopressin and this caused a significant reduction in intravariceal pressure (15.6 +/- 2.6 vs 10.3 +/- 2.9 mmHg, P < 0.0001). The average basal intravariceal pressure in these patients was 15.8 +/- 3.1 mmHg. After intravariceal pressure was recorded, the needle was left in situ and endoscopic sclerotherapy commenced immediately. During the investigation, no adverse reaction or complication was encountered. It was concluded that the measurement of intravariceal pressure by fine needle direct puncture followed by immediate sclerotherapy is a safe and simple method to evaluate the short-term effect of drug prevention from oesophageal variceal bleeding and that vasopressin causes reduction of intravariceal pressure.
Aged↗
Clinical value of tumour markers and serum-ascites albumin gradient in the diagnosis of malignancy-related ascites.
To determine the clinical value of tumour markers in the diagnosis of malignancy-related ascites (not including hepatocellular carcinoma), serum and ascitic fluid levels of carcinoembryonic antigen, cancer antigen 125, carbohydrate antigen 19-9, tissue polypeptide antigen and serum-ascites albumin gradient were determined in 66 patients with cirrhotic ascites, 28 patients with hepatocellular carcinoma and ascites, and 29 patients with malignancy-related ascites. Three tumour markers and serum-ascites albumin gradient showed significant difference between patients with malignancy-related ascites and those without: serum carcinoembryonic antigen (26.4 +/- 31.5 vs 4.8 +/- 4.6 ng/mL, P < 0.01), ascitic fluid carcinoembryonic antigen (118.4 +/- 196.5 vs 2.0 +/- 1.4 ng/mL, P < 0.01), ascitic fluid carbohydrate antigen 19-9 (12,933 +/- 25,496 vs 23 +/- 67 U/mL, P < 0.01) and serum-ascites albumin gradient (1.1 +/- 0.4 vs 2.0 +/- 0.4 g/dL, P < 0.01). At the best cut-off levels chosen from near 95% of the data in those without malignancy-related ascites, the sensitivity, specificity and accuracy to diagnose malignancy-related ascites were, respectively, 65.5%, 93.6%, 87.0% using serum carcinoembryonic antigen > or = 10 ng/mL; 69.0%, 94.7%, 88.6% using ascitic fluid carcinoembryonic antigen > or = 5 ng/mL; 65.5%, 93.6%, 87.0% using ascitic fluid carbohydrate antigen 19-9 > or = 50 U/mL; 62.1%, 98.9%, 90.2% using serum-ascites albumin gradient < 1.1 g/dL. Although serum-ascites albumin gradient offered the best diagnostic accuracy and specificity, its sensitivity was not good enough. Our study indicates that serum-ascites albumin gradient and tumour markers are not sensitive parameters in the diagnosis of malignancy-related ascites.
Ascites↗
Total paracentesis in non-alcoholic cirrhotics with massive ascites: mid-term effects on systemic and hepatic haemodynamics and renal function.
Single total paracentesis (4.8-11 L) was performed in 23 patients with hepatitis B surface antigen (HBsAg)-positive cirrhosis and massive ascites and its effects on systemic and hepatic haemodynamics and renal function were examined over 5 days. Severe hypotension occurred in six (26.1%) patients from 6 to 54 h after paracentesis. In the remaining 17 patients, compared to the baseline, there was an increase in the cardiac output (6.1 +/- 0.3 vs 6.7 +/- 0.3 L/min, P < 0.001) and a decrease in right atrial pressure (8.8 +/- 0.8 vs 4.3 +/- 0.7 mmHg, P < 0.001), systemic vascular resistance (1160 +/- 61 vs 976 +/- 50 dyne.s.cm-5, P < 0.001), and wedged hepatic venous pressure 30 min after completion of paracentesis. After 5 days, right atrial pressure, systemic vascular resistance and wedged hepatic venous pressure returned to baseline, while the cardiac output dropped to a level lower than the baseline (5.7 +/- 0.7 L/min, P < 0.05). Hepatic venous pressure gradient had returned to baseline after 5 days. Serial tests of serum creatinine level showed an increase from day 3 (1.34 +/- 0.14 vs 1.04 +/- 0.10 mg/dL, P < 0.05). On day 5, creatinine clearance (55.7 +/- 5.4 vs 41.9 +/- 5.3 mL/min, P < 0.05) and effective renal plasma flow (351 +/- 32 vs 293 +/- 29 mL/min, P < 0.05) were decreased, compared to the baseline. Based on these data, infusion of a volume expander may be necessary for total paracentesis to avoid systemic haemodynamic complications in non-alcoholic cirrhosis.
Ascites↗
Clinical trials of HCC in Taiwan.
Tumors of the liver represent one of the most common malignancies in the world. Little has changed in the past 5 years to alter the statistics. Published census from the Department of Health in Taiwan, 1993, showed that cancer death was 107/100,000 population. Hepatoma is the number one cause of cancer death with 24.05/100,000 population. It increased 11.23% in comparison with last year's survey. About 5,000 people die from hepatoma each year in Taiwan. Both case control studies and cohort studies have shown a strong association between chronic hepatitis B carriage rate and an increased incidence of hepatocellular carcinoma (HCC). Although up to a 200-fold excess incidence of HCC was found in Taiwan, the association of chronic hepatitis B virus in different populations of Southeast Asia who have HCC is somewhat varied. Many treatment modalities for hepatoma have been attempted. Chemotherapy is usually given to patients with metastatic disease or for persistent or recurrent disease. The consensus is that no single drug or combination of drugs given systemically leads to a reproducible response rate of more than 25% or has any effect on survival, or survival beyond that of untreated control. The identification of new, effective chemotherapy drugs and other modality treatments for advanced stage HCC is urgently required. We report here the results regarding response rates, toxicities, and survivals of 14 on-going and finished Phase I, II and III clinical trials on hepatoma. These include chemotherapy and/or biological modifier, radioisotope, hormone, and hepatic infusion. Nine future therapies and gene therapies will also be discussed.
Antineoplastic Agents↗