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Biomedical subjects

C Ellis

Publications and source records attributed to C Ellis.

14 recordsLinked to original sources
PubMed1979

Reverse transcriptase from avian myeloblastosis virus.

From lots of 20 to 30 g of avian myeloblastosis virus RNA-dependent DNA polymerase was obtained in preparations of purity greater than 95% by using a two-step column chromatographic procedure employing DEAE (DE 52) and carboxymethylcellulose (CM 52.). Yields of RNA-dependent DNA polymerase varied from approximately 20,000 to 35,000 U/g of virus. Specific activity of the enzyme was about 35,000 to 60,000 U/mg of protein. Free of detectable RNase activity, the product exhibited a molecular weight of about 160,000, an isoelectric point of 6.5, and approximately 2 mol of fatty acid per mol of enzyme.

Animals↗
PubMed1979

Bile acid metabolism in the cirrhotic rat.

Bile acid metabolism was studied in rats with cirrhosis induced by carbon tetrachloride (CCl4). Although the typical histologic features of cirrhosis were seen, cholestasis was not present in these animals as evidenced by a normal total serum bilirubin concentration and by a normal hepatic capacity to remove taurocholate infused intravenously. The cirrhotic rats also secreted taurocholate into bile at a normal rate. The total bile salt pool size in the cirrhotic rats was not significantly different from the pool size in normal rats (10.59 +/- 1.19 mumoles per gm. of liver (+/- 1 standard error of the mean) and 10.43 +/- 0.92 mumoles per gm. of liver, respectively). When the bile was drained externally through a chronic bile fistula, the normal rats increased the bile salt synthetic rate approximately 3-fold after 48 hours of drainage. However, the cirrhotic rats failed to significantly increase the synthetic rate for bile salts in response to biliary drainage. The normal rats also had a significant increase in cholic acid synthesis at the maximal synthetic rate, whereas the cirrhotic rats did not. These findings indicate that (when feedback inhibition is removed) CCl4 cirrhotic rats lack the ability to normally increase the activity of 7 alpha-hydroxylase and 12 alpha-hydroxylase, rate-limiting enzymes in the synthesis of bile salts.

Animals↗
PubMed1979

Serum isoamylase measurements in pancreatitis complicating chronic renal failure.

This investigation was designed to determine whether serum isoamylase measurements can aid in establishing the diagnosis of acute pancreatitis in renal failure patients. Twenty-two hemodialysis patients were studied, four of whom had documented acute pancreatitis. Total serum amylase and pancreatic isoamylase concentrations were significantly higher (p less than 0.02) in the pancreatitis patients than in the 18 patients without pancreatitis, but there was appreciable overlap between these two groups. In each of the four patients with pancreatitis, the percentage of serum amylase derived from the pancreas (range, 80% to 90%) was well above the highest value (67%) observed in the patients without pancreatitis. These results suggest that determination of the percentage of serum amylase represented by pancreatic isoamylase is of assistance in establishing the diagnosis of acute pancreatitis in renal failure patients.

Acute Disease↗
PubMed1978

Protein kinase from avian myeloblastosis virus.

A protein kinase associated with purified virions of avian myeloblastosis BAI strain A was partially purified by ion-exchange chromatography and gel filtration. The transfer of phosphate catalyzed by this enzyme required a divalent metal ion and ATP as phosphate donor. GTP could not be substituted for ATP, and the reaction was unaffected by either cyclic AMP or beef-heart protein-kinase inhibitor. Of the virus and nonvirus proteins tested as phosphate acceptors, only acidic proteins were phosphorylated. In particular, purified preparations of reverse transcriptase from avian myeloblastosis virus did not accept phosphate. The enzyme is a basic protein (pI = 9.3), and, on the basis of molecular sieving through Sephadex G-200 and velocity sedimentation on glycerol gradient, the protein kinase has a molecular weight of 45,000.

Adenosine Triphosphate↗
PubMed1975

Effect of high dose spironolactone and chlorthalidone in essential hypertension: relation to plasma renin activity and plasma volume.

The effect on blood pressure of high (400 mg/day-S400) and moderate dose (200 mg/day-S200) spironolactone and chlorthalidone (100 mg/day-C100), given in a random double-blind manner was related to plasma renin activity and plasma volume in 38 essential hypertensives. The fall in pressure from a control of 154/103 mm Hg was essentially the same after four weeks of each drug--S400 deltaBP 24/13 mm, S200 18/9 mm, C100 17/12 mm (all P less than 0-001). Twelve of 37 patients (32%) had low initial renin, but this appeared as responsive to the chlorthalidone stimulus as that of the normal renin group. The antihypertensive effect of all regimens was unrelated to plasma renin activity. Plasma volume was significantly lowered at the end of each treatment period, but the decline could not be correlated with blood pressure effects. Patients with initially low plasma volume were more likely to respond to S400 (r = 0-545, P less than 0-001), whereas the antihypertensive effect of the S200 and C100 regimens was independent of this variable.

Adult↗
PubMed1975

Altered cardiac responsiveness and regulation in the normal cardiac output type of borderline hypertension.

Of 145 patients with borderline hypertension, 30% had increased resting cardiac index (QI), whereas the remainder had normal values. The specific aim of this study was to investigate cardiac regulation in patients who had normal resting QI. Eighty-five control subjects were used for comparison. At rest, patients with normal QI showed evidence of decreased parasympathetic inhibition; the QI after injection of atropine increased less than in control subjects. After complete cardiac autonomic blockade with propranolol and atropine, QI and stroke volume were significantly lower in patients than in control subjects. The mechanism of this low QI was further analyzed. Central blood volume, which strongly correlates with stroke volume, was used as an estimate of the cardiac venous filling. After blockade, stroke volume was decreased in patients, but central blood volume was normal. Patients also showed a decreased heart rate and QI response to infusion of isoproterenol. It is therefore postulated that two components may be responsible for the low QI in the "denervated" heart: patients exhibit a decreased responsiveness to sympathetic stimulation, and they may also be less responsive to venous filling. Behind the facade of cardiac normality in these borderline hypertensive patients with normal cardiac output, there is evidence of altered autonomic control of the heart (decreased vagal inhibition) and of changed cardiac response to sympathetic stimulation and possibly to venous filling.

Adult↗
PubMedDate not supplied

Which three-year-olds attend preschool facilities?

In an epidemiological survey of a total population of three-year-old children living in a London borough, information was obtained on the behaviour, development and social characteristics of 828 children. Details were extracted from the registers of 27 preschool facilities in the borough (a residential nursery, day nurseries, play groups and nursery schools and classes) on all children attending over an 18-month period. The patterns of attendance and factors influencing attendance of about 3000 children are discussed. The comparison of children attending facilities in the original sample of 828 with the total sample shows that those children most in need are not over-represented in these preschool groups.

Child Behavior Disorders↗