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Biomedical subjects

R B Stern

Publications and source records attributed to R B Stern.

14 recordsLinked to original sources
PubMed1984

The stoichiometry of A23187- and X537A-mediated calcium ion transport across lipid bilayers.

Initial rates of ionophore-mediated Ca2+ transport across egg phosphatidylcholine bilayers of large unilamellar vesicles were measured using the absorbance change of arsenazo III at 650 nm as an indicator of Ca2+ translocation. A23187 induced the movement of Ca2+ in a 2:1 ionophore: Ca2+ complex, whereas its methyl ester (CH3A23187) and X537A mediated Ca2+ movement in a 1:1 ionophore: Ca2+ complex. The relative potencies of these ionophores in transporting Ca2+ across lipid membranes were A23187 much greater than X537A greater than CH3A23187.

Arsenazo III↗
PubMed1977

Controlled trial of synthetic D-penicillamine and prednisone in maintenance therapy for active chronic hepatitis.

In view of promising, but uncontrolled, reports of the use of D-penicillamine in active chronic hepatitis, a randomised, prospective, controlled trial of this drug against prednisone was carried out. Of the 35 patients entered, 18 received D-penicillamine (increasing to 1-2 g daily) and 17 prednisone (15 mg daily). In all patients the disease had already been brought under biochemical control with corticosteroids. During the first year of the trial, the treatment of nine patients in the D-penicillamine group was discontinued (two because of lack of disease control and seven because of side-effects) compared with six patients in the prednisone group (four because of lack of disease control, one because of side-effects, and one because of the development of carcinomatosis. Detailed statistical analysis of the liver function tests in the patients remaining in the trial at the end of the year showed no significant differences. D-penicillamine is associated with a higher frequency of side-effects than is prednisone. However, in some patients it is as satisfactory as prednisone in keeping the disease under control.

Adolescent↗
PubMed1975

Use of computer program for diagnosing jaundice in district hospitals and specialized liver unit.

A computer-assisted model for diagnosing jaundice has been adapted for use on the University of London C.D.C. 7600 computer via an on-line terminal at King's College Hospital to provide a rapid turn-round time. The model was used prospectively in the diagnosis of 219 patients--135 seen in a specialized liver unit and 84 seen in one of four district hospitals in south-east London--with an overall accuracy in distinguishing among 11 different causes of jaundice of 69% and 62% respectively. These figures rose to 77% and 88% respectively when only those patients in whom the final diagnosis reached a "certain" probability were considered. When used to distinguish between a medical and a surgical cause of jaundice the accuracy was 86% in the liver unit and 77% in the district hospitals, rising to 95% in both series for those with a diagnosis of certain probability. The proposed improvements to the model--namely, the use of two deparate data bases and more diagnoses within the matrix--should be improve the accuracy even further. In practice the rapid feedback to the clinicians looking after patients provided help in managing difficult cases.

Bile Duct Neoplasms↗
PubMed1973

Use of computer-assisted model in diagnosis of drug hypersensitivity jaundice.

Of 374 patients with jaundice seen in the liver unit over a four-year period 21 were finally thought to be hypersensitive to one of seven different drugs. The clinical, laboratory, and histological features were often difficult to distinguish from those of viral hepatitis, tumour of the extrahepatic biliary tree, or primary biliary cirrhosis. A computer-assisted diagnostic model made use of minor differences, and made a correct diagnosis in all patients. Even when information about drug ingestion was left out it was still correct in 81% of patients. Sixty-four other patients gave a history of ingestion of potentially hepatotoxic drugs of whom 62 were correctly diagnosed by the computer. In the complete series of 374 patients only two were incorrectly computed to have drug jaundice when there was no history of drug ingestion.Two additional patients became jaundiced after exposure to drugs, but were found to have primary biliary cirrhosis.

Biliary Tract↗
PubMed1973

Use of sequential Bayesian model in diagnosis of jaundice by computer.

A sequential Bayesian model has been developed for a computer and used to diagnose jaundiced patients admitted to hospital. Up to 102 items of information from the history, physical examination, and special investigations available within 48 hours of admission were collected on 309 patients. The results from these patients were used to calculate the probabilities of 11 possible diseases in 65 new patients and also to place patients into groups for medical or surgical treatment.The overall accuracy of the model in diagnosing patients as having one of 11 diseases was 69%, and where the final probability reached > 0.96, it was 89%. The overall accuracy in making a medical or surgical decision was 89%, and where the final probability reached > 0.96 it was 94%.Improvement in accuracy should result as the number of cases seen with rare conditions increases, and probably a similar model could be developed and used to make most use of those indicants with the highest cost-effectiveness.

Acute Disease↗
PubMed1973

Pitfalls in the diagnosis of jaundice due to carcinoma of the pancreas or biliary tree.

Analysis of 56 patients with obstructive jaundice due to carcinoma of the pancreas or extrahepatic biliary tree showed that unexpected features were present in 25%. Presentation with painless jaundice was uncommon, and the symptoms were more often non-specific, with malaise, anorexia, and vomiting. Abdominal pain was frequent, and the condition was found in young patients. One-fifth presented with serum alkaline phosphatase levels of less than 30 K.A. units. Some had high serum aspartate aminotransferase levels, more characteristic of hepatocellular jaundice. A mathematical model may be helpful in correctly weighting these various criteria.

Abdomen↗