Search PubMed⌕ Search

Biomedical subjects

C J Watson

Publications and source records attributed to C J Watson.

At least 163 records · Page 9Linked to original sources
PubMed1985

Pharmacokinetics of ranitidine in quadriplegics.

In a previous study we observed that quadriplegic patients were unresponsive to ranitidine given in high dose (600 mg day-1 intravenously) for prophylaxis of stress ulceration. The pharmacokinetics of 100 mg of intravenous ranitidine have therefore been studied in six male quadriplegic patients. Plasma drug concentrations declined in a biexponential fashion. The mean (+/- s.e. mean) distribution half-life was 9.42 (+/- 1.04) min. The terminal plasma elimination half-life 1.79 (+/- 0.12) h, the volume of distribution 103 (+/- 17) litres and total body clearance 663 (+/- 86) ml/min. These values are similar to those described in two published studies performed in normal male volunteers. This suggests that there is no pharmacokinetic reason for the quadriplegics to be resistant to ranitidine and the defect is likely to be related to vagal control of acid secretion.

Adult↗
PubMed1985

An exploration of the attitudes, personality and performance of dental students.

This study investigates (1) the behavioural patterns, performance and attitudes to dentistry and (2) the personality traits, in male and female dental students (n = 219) studying at Cardiff Dental School. The first part deals with the results of a questionnaire investigating aspects of the students' training course, interests in various fields of dentistry, the level of frustration, anxiety and fatigue felt, the overall feelings of satisfaction and dissatisfaction produced in their dental course, their reasons for entering dentistry and their hopes for a future career, as well as their various leisure and spare-time activities. The second part examines the personality traits of clinical stage students (n = 123) based on Cattell's personality questionnaire, the 16 PFQ form C. The results were correlated with students' 'A' level grades, interview grades, clinical examination results and responses to some items of the general questionnaire. It was possible to identify certain characteristics in dental students which implied likely success in their dental examinations. This may have a useful implication for the initial selection of those wishing to practise dentistry.

Attitude of Health Personnel↗
PubMed1985

Randomized, prospective trial of cimetidine and ranitidine for control of intragastric pH in the critically ill.

Forty-eight critically ill patients in an intensive care unit were enrolled in a prospective study of stress ulcer prophylaxis. The H2-receptor antagonists cimetidine and ranitidine were used, patients being randomized on hospital number. Response was assessed by measuring gastric pH every 2 hours. The drugs were administered by intravenous infusion, and up to three dosage increments fo each of the drugs were titrated against the pH of the aspirated gastric juice. If one drug, in maximum dose, failed to maintain the pH above 4, the other drug was administered at maximum dose. If both drugs failed to achieve control of gastric pH, antacids were administered in an endeavor to ensure patient safety. Cimetidine was successful in maintaining the intragastric pH above 4, for the duration of the intensive care admission, in five of 28 patients. Ranitidine was successful in 10 of 20 patients. The difference between these two groups was statistically significant (p = 0.04). In patients in whom cimetidine therapy failed, ranitidine provided adequate control of pH in four of 13. Cimetidine controlled one of six patients who had failed to improve with ranitidine therapy. Plasma concentrations of both drugs were well above established acid inhibitory concentrations. However, even with much lower plasma concentrations of ranitidine, similar amounts of both drugs were present in the gastric juice, suggesting a possible explanation for the greater efficacy of ranitidine. We conclude that, although ranitidine is more effective than cimetidine, neither of these drugs is adequate for stress ulcer prophylaxis. If they ae used for this purpose in the critically ill patient, regular monitoring of gastric pH is essential to allow detection of therapeutic failures.

Cimetidine↗
PubMed1982

The structure and expression of the preproenkephalin gene.

Enkephalins are pentapeptides with opioid activity which are found in a wide variety of tissues. Studies of enkephalin-containing peptides from the adrenal gland have established that the mature pentapeptides are derived by proteolytic processing of a precursor protein. We have shown that human adrenal medullary tumours contain mRNA which can be translated in vitro to yield a single major enkephalin precursor. The sequence of cloned cDNA shows that the preproenkephalin mRNA encodes four copies of met-enkephalin, two copies of met-enkephalin extended sequences and one copy of leu-enkephalin; each copy is flanked by paired basic amino acids which are presumably recognised by the processing protease. We have used the cloned human cDNA as a hybridisation probe to detect the corresponding mRNAs in rat adrenal gland and, in smaller amounts, in rat brain. We have been unable to detect in brain any other cross-hybridising mRNAs which might encode other putative precursor proteins.

Adrenal Gland Neoplasms↗
PubMed1982

Applications of multidimensional computer graphics in medical systems.

Multidimensional computer graphics are demonstrated in two medical systems applications in this paper. First, multidimensional computer graphics are utilized for descriptive purposes to show the differences among 10 physician specialty groups for multivariate data available at admission to medical school. Second, multidimensional computer graphics are demonstrated as a method that can be used for screening school applicants. The novel method utilized to represent multivariate data requires the plotting of a face. Each feature of a face--for example, face height or ear diameter-can be utilized to represent a different dimension of multivariate data. Each face then represents a vector whose elements are the mean values of multiple variables, or it represents a multivariate observation.

Career Choice↗
PubMed1980

Hematin therapy in porphyric attacks.

We report our experience with hematin in the treatment of 57 patients in porphyric attacks. The ratio of acute intermittent porphyria: variegate porphyria: hereditary coproporphyria was 43:11:3. More than 90% of the patients showed not only a decline in their porphyrin precursors, but also a favor able clinical response. Hematin was well tolerated and should be considered the treatment of choice in porphyric relapse.

Heme↗
PubMed1979

A predictive and descriptive model of interns' hospital selections.

This paper examines the differences among medical students who have chosen different types of hospitals for internship training. The criterion variable of a medical student electing to take internship training in a government, private, public, or university hospital is analyzed using admissions, medical training, and practice data as independent variables. Multiple discriminant analysis is employed to evaluate the profiles of physicians who have taken internship training in the different types of hospitals. Classification rates were found to be somewhat accurate. Computer graph plots of discriminant analysis mappings are used to depict differences among the hospital-based internship groups. The results of applying these techniques and methods are of value for more efficient hospital administration.

Career Choice↗
PubMed1979

A note on computer graph plots of physician practice locations.

This note examines the distribution of a medical school's physician graduates among states. Computer graphy plots of this distribution are shown to be an alternative way of providing information to health care administration decision-makers concerned with physician practice location.

Computers↗
PubMed1979

Uroporphyrinogen I synthase from human erythrocytes: separation, purification, and properties of isoenzymes.

Uroporphyrinogen I synthase [porphobilinogen ammonia-lyase (polymerizing), EC 4.3.1.8] from human erythrocytes was separated into two active protein peaks (A and B on DEAE-cellulose, by ammonium sulfate fractionation, on Sephadex G-100, and on DEAE-Sephadex A-50 with a NaCl gradient. The final purification was 613 and 743 times for A and B, respectively. The corresponding yields were 2.2 and 3.4% Fraction A was separated further into two (A1 and A2) active protein bands and fraction B into three (B1, B2, and B3) on analytical polyacrylamide disc gel electrophoresis. Bands A1 and A2 were identical with B1 and B2; B3 represented a third isoenzyme. Molecular weights (mean +/- SEM), measured by gel filtration and sodium dodecyl sulfate/polyacrylamide gel electrophoresis, were 38,000 +/- 1000 for B1 and 40,000 +/- 1000 for B2 and B3. Isoelectric focusing on 4% polyacrylamide gel separated both fractions A and B into three active protein bands. Maximal activity of the enzyme was found in gel cuts (5-mm) at pH 5.6 for both fractions A and B.

Ammonia-Lyases↗