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Biomedical subjects

W E Smith

Publications and source records attributed to W E Smith.

At least 109 records · Page 6Linked to original sources
PubMed1987

A 1H spin echo NMR study of the HeLa tumour cell.

Phosphorylcholine, phosphorylcreatine, lactate, glutathione, glycine and leucine were identified in living HeLa cells in the first study of this cell type by 1H spin echo NMR spectroscopy. The technique has the advantage that it is non-invasive, providing detailed structural information on individual species present in the cell matrix. It has been used in this case to study the rate of energy consumption following the activation of the glycolytic pathway with glucose.

Energy Metabolism↗
PubMed1987

Determination of alpha-tocopherolquinone (vitamin E quinone) in human serum, platelets, and red cell membrane samples.

A high-performance liquid chromatographic method for the determination of alpha-tocopherolquinone in a few selected biological samples is reported. Samples of human serum, blood platelets, or red cell membranes were saponified and extracted with hexane. A measured aliquot of the extract was evaporated under a stream of nitrogen, and the residue was reconstituted with mobile phase (methanol:water, 98:2) and used directly for liquid chromatography. alpha-Tocopherolquinone was separated on Zorbax C-18 columns (25 cm X 4.6 mm, 5-microns particles) and detected by its absorption at 265 nm. The addition of high levels of base during saponification as well as exposure to fluorescent light results in loss of the quinone. Concentrations of alpha-tocopherolquinone in normal human serum are exceedingly small constituting only 0.02-0.05% of the alpha-tocopherol concentration. The technique is particularly useful in the quantitation of the oxidation of alpha-tocopherol in biological samples under in vitro conditions. For example, incubation of human platelets with diamide or arachidonate resulted in oxidation of alpha-tocopherol and the alpha-tocopherolquinone produced accounted for 11.8 and 30.6%, respectively of the alpha-tocopherol lost.

Blood Platelets↗
PubMed1987

Alteration of thiol and superoxide dismutase status in rheumatoid arthritis treated with sulphasalazine.

Intracellular thiols (LSH), superoxide dismutase (SOD) and plasma thiols (PSH) are thought to have an important role in the protection of tissues from damage by oxygen-derived free radicals. The change in the levels of activity of these substances in patients with active rheumatoid arthritis treated with sulphasalazine for 6 months was assessed in 22 patients. Over this time there was a marked improvement in disease activity. This was accompanied by an early increase in red cell LSH and decrease in SOD, although by 6 months these changes had completely reversed. In addition the negative correlation between these indices at week 0 had disappeared by week 6. Over the 6 months there was a steady rise in PSH. The change in PSH is slow and is thus more likely to reflect a change in the disease process rather than an active role for the thiol, but the early changes in intracellular parameters may be of importance in the action of this drug. These changes are similar to changes found with other second-line drugs. It is also of interest that a drug which does not itself possess a thiol group is capable of altering the thiol status of cells.

Adult↗
PubMed1987

Hotelling trace criterion and its correlation with human-observer performance.

The Hotelling trace criterion (HTC) is used to find a set of linear features that optimally separate two classes of objects. The objects used in our study were simulated livers with and without tumors, with noise, blur, and object variability. Using the receiver-operating-characteristic parameter da as our measure, we have found that the ability of the HTC to separate these objects into their correct classes, by detecting the presence or absence of a tumor, has a correlation of 0.988 with the ability of humans to separate the same two classes of objects. This suggests, therefore, that the HTC can be used as a figure of merit for optimizing system parameters, since it calculates a single, scalar figure of merit that has a high correlation with human-observer performance.

Humans↗
PubMed1986

Changes in glutathione in intact erythrocytes during incubation with penicillamine as detected by 1H spin-echo NMR spectroscopy.

1H spin-echo NMR spectroscopy was used to study changes in glutathione status in intact erythrocytes. The concentration of glutathione in suspensions of erythrocytes in 2H2O saline is significantly different in cells from patients with rheumatoid arthritis than in controls from normal healthy volunteers. It is observed that the methods of separation and suspension affect lactate metabolism in red cells. Incubation of erythrocytes with solutions of the therapeutic agent D-penicillamine in 2H2O saline produced a change in glutathione resonances which is indicative of an increase in diglutathione concentration. Signals from the methyl groups of penicillamine decreased at a commensurate rate. Incubation of normal cells with plasma from patients with rheumatoid arthritis who had the same blood group as the normal volunteer indicated a much larger fall in glutathione signal with plasma from a patient treated with penicillamine than from a patient on non-steroidal anti-inflammatories.

Anti-Inflammatory Agents↗
PubMed1986

Early and late changes in sulphydryl group and copper protein concentrations and activities during drug treatment with aurothiomalate and auranofin.

Superoxide dismutase activity (SOD), plasma and lysate thiol concentrations (PSH and LSH), and caeruloplasmin oxidase activity (CP) reflect the underlying reduction-oxidation imbalance associated with rheumatoid arthritis (RA), and are believed to be involved in the protection of the cell against free radical activity. The early and late changes in these parameters have been observed and compared with standard clinical and biochemical assessments of disease activity in 90 patients with active RA, randomly assigned to receive either sodium aurothiomalate, auranofin, or auranofin placebo. An index based on clinical criteria was used to identify patients as responders or non-responders after 24 weeks of therapy. In the first six weeks of treatment a change in SOD activity and LSH concentration in a direction away from controls was followed by a return towards control levels in responders only. This suggests that in RA evidence of clinical improvement induced by gold drugs is preceded by an initial biochemical response in an inflammatory direction. The extracellular parameters PSH and CP did not show the same early response, but PSH levels in responders showed a slower change towards normal values, though at no time were values obtained that might suggest a complete remission. Thus the intracellular parameters appear to reflect an early effect of the drugs on cells which may possibly be of use in predicting the outcome of therapy, whereas the extracellular parameters provide confirmatory evidence for an eventual improvement.

Arthritis, Rheumatoid↗
PubMed1986

Ethical, economic, and professional issues in home health care.

Important ethical, economic, and professional issues in home health care (HHC) are identified and discussed. Patient services issues in HHC involve the ethics of providing high-technology feeding therapies to terminally ill patients and the controversies surrounding drug products, such as the appropriate amount of drug to be dispensed, the appropriate individual to compound home-care drug products, acceptable types of product packaging, and the impact of a switch in venders on the drug products supplied to patients. Economic issues include reasonable profit for HHC services, methods used to charge for products and services, payments to physicians for patient referrals, and pharmacies owned and operated by the HHC industry. Pharmacy relations issues center on the influence of nonpharmacists on pharmacy-based HHC services and the effect of HHC services on intraprofessional relations. How pharmacists resolve the many ethical, economic, and professional issues in HHC will determine the quality of services provided to patients, the nature of the working relationships between pharmacists and other health professionals, and the direction that pharmacy HHC services will take in the future.

Drug Industry↗
PubMed1985

Image reconstruction from coded data: I. Reconstruction algorithms and experimental results.

Two algorithms have been developed for reconstructing objects from their coded images and a priori knowledge of the object class. Reconstructions from both algorithms are presented, but the results appear to be largely independent of the algorithm used. One of the algorithms, a Monte Carlo approach, is used to investigate the quality of the reconstruction of two- and three-dimensional objects from simulated coded-image data with respect to viewing geometry and multiplexing (mixing) of the data. The cases examined include reconstructions from data with and without signal-dependent photon noise. It is found that reconstructing from multiplexed data is not so serious a problem as reconstructing from data obtained with a limited viewing angle. Also, when photon noise is included in the data, reconstructions obtained from multiplexed data are better than those obtained from unmultiplexed data because of the higher photon count made available by multiplexing. It appears that the fidelity of a reconstruction depends much more strongly on the design of the data-taking system (the coded apertures) than on the reconstruction algorithm.

Models, Structural↗
PubMed1985

Image reconstruction from coded data: II. Code design.

A strategy is given for the design of coded apertures with respect to a given class of objects that are to be imaged. Previous knowledge of the first- and second-order statistics for the object class is assumed. The object class is characterized by its Karhunen-Loève eigenvectors and eigenvalues, whereas the imaging system is characterized by its singular-value decomposition. We introduce the concept of alignment in which the aperture parameters are adjusted until the system is tuned to measure the given object class well. A mean-square-error figure of merit that indicates degree of alignment is given, and alignment is performed by standard optimization techniques. We illustrate this technique with a simple proof-of-principle experiment. These concepts are general and may be applied to any linear imaging system.

Models, Structural↗
PubMed1985

Implications of the new technology for pharmacy education and practice.

Educators and practitioners in the health professions are faced with two questions as they attempt to adapt to changes brought by new technology. What is the nature of the technology? and What are the implications for education and practice? The present paper directs these questions to pharmacy in a three-part discussion: the implications of the technology; the relevant technology presented as brief, descriptive vignettes; and comments on the apparent problems which are created by technological change. The implications are presented first, as a set of general guidelines, second, the implications for the knowledge and skill components of education and practice, and third, as attitudes required by pharmacists and pharmacy students. The paper concludes with a list of still unanswered questions relative to the future.

Computers↗
PubMed1985

Implications of new technology for pharmacy education and practice.

Specific knowledge and skills needed by pharmacists in an era of advancing health-care technology are presented, and the most important modern technologic developments in health care are described briefly. Implementation of new technology in health care will be affected by cost considerations and by social trends such as shifting population demographics, an increase in diseases of lifestyle, consumerism, and self-care. Technologic advances in the following areas are described: computerized information networks, bioelectronics, biotechnology, computer graphics, diagnostic imaging, and drug development in space and in the oceans. Diseases are noted for which diagnosis and treatment using new technology is promising. The roles of interferon and monoclonal antibodies are described, and trends in development of new drugs and drug delivery systems are traced. A new philosophical basis for pharmacy education that is consistent with the needs of a technologically oriented society is needed. Practitioners will look to their professional societies for assistance in identifying and implementing the new technology.

Antibodies, Monoclonal↗
PubMed1984

Electroconvulsive therapy: a Canadian perspective.

Recent ECT practices in Canada are reviewed from a historical perspective with respect to specific criticisms. Utilization is decreasing; utilization rates vary widely between Provinces and between regions; disproportionate numbers of females have been receiving ECT; a substantial group of patients diagnosed as neurotic and schizophrenic continue to receive ECT; criteria and guidelines for its use are not consistently applied. Expected rates of ECT used are estimated, based on theory and practice as well as on published data on the epidemiology of affective disorders. Data on actual Canadian usage are reviewed and compared with an estimated minimum ratio of 30-45+ cases per year of non bi-polar depression per 100,000 population requiring ECT. Results show that there may be a substantial number of patients in some Provinces for whom ECT is the best available treatment and who are not receiving it. There is some ethical concern associated with possible under-use of ECT as the best therapy available for certain patient groups. Clinical cases and patterns of care should be reviewed at the hospital level to determine how best to effect improvements in the use of this treatment.

Adult↗
PubMed1984

Effect of an automated bedside dispensing machine on medication errors.

The effect of an automated bedside dispensing machine on medication errors was studied on a 32-bed surgical unit of an 848-bed hospital. The experimental system (McLaughlin Dispensing System) included at each patient's bedside a locked medication cabinet that was electronically programmed to allow the nurse access to doses due at a particular time. The control system was a decentralized unit dose system. A crossover study design with random assignment of subjects and treatments was used. In the 14-day study period, nurses were observed by a pharmacist for 28 five-hour periods as they administered medications on the day and evening shifts. The mean error rates were significantly different--10.6% for the experimental system and 15.9% for the control system. Wrong time errors were the most common type. No significant differences were found between day and evening shifts or workloads of individual nurses. There was no treatment order effect. The error rate was significantly lower for the automated dispensing system than for the system using unit doses dispensed from a satellite pharmacy. Automated dispensing systems may be useful in reducing errors in administration time and dose omissions.

Computers↗