Biomedical subjects
Publications and source records attributed to J W Winkelman.
Various strategies for cutting costs in the hospital clinical laboratory are noted, including straight cost cutting, modifications of internal operations, degradation of functions and services, reduced utilization, shared hospital services, and reorganization. Dr Winkleman defines quantitatively, where data exist, the actual cost savings that the different options have been claimed to produce.
Economic forces have been set in motion by recent legislation that are very likely to reduce available funds for clinical laboratories in hospitals. The effect of these impending developments on patient care is of great concern to clinicians and laboratorians. There is a range of available coping strategies that have broadly different consequences for the traditional role of the laboratory in patient care. The first seeks to preserve existing test ordering and reporting behavior by employment of straight cost cutting in the laboratory. The second calls for consciously determined selective degradation in laboratory services and functions. The third depends on decreased utilization of the laboratory achieved by indirect or direct intervention by laboratorians on the free ordering practices of clinicians. The fourth involves reorganization of the laboratory with new institutional relationships that variably affect laboratory function.
Decreases in true expenses in the hospital clinical laboratory consequent to reduced utilization were estimated from four models. Each category of direct expense was adjusted according to projections and confirmed to the extent possible by actual experience. No projections of reductions in indirect expenses were made. Savings with reductions in utilization of 10 and 50 per cent of a single high-volume automated test amounted to 1.32 and 18.11 per cent of total expenses, respectively. Savings with reductions of 10 and 50 per cent in utilization of all tests amounted to 3.88 and 21.55 per cent, respectively. These modest savings should be important to the financial planning efforts of laboratory managers and institutional administrators confronted with cost-reduction mandates.
We devised a positive selection procedure for bacterial mutants incapable of producing acid from sugars by fermentation. The method relied on the production of elemental bromine from a mixture of bromide and bromate under acidic conditions. When wild-type Escherichia coli cells were plated on media containing a fermentable sugar and an equimolar mixture of bromide and bromate, most of the cells were killed but a variety of mutants unable to produce acid from the sugar survived. Among these mutants were those defective in (i) sugar uptake, (ii) the glycolytic pathway, and (iii) the excretion. There were also novel mutants with some presumed regulatory defects affecting fermentation.
To further the accurate direct potentiometry of plasma electrolyte concentrations, we investigated the effects of solution composition on the residual liquid junction potential (RLJP) during measurement of K+. Assuming that the binding constant between K+ and proteins or bicarbonate is no greater than with Na+, we calculate that the amount of bound K+ can be neglected. A significant RLJP exists between simple solutions containing Na+, K+, and Cl- ions and solutions containing Na+, K+, Cl-, and HCO3- ions. Replacing Cl- with HCO3- leads to an increase in the RLJP, which in turn contributes to a negative error in K+ analysis. A small decrease in RLJP is observed as the ionic strength is increased. The Henderson equation gives a reasonable estimate of the magnitude of the observed RLJP, even though the liquid junction does not meet the conditions under which the equation is rigorously applicable. Errors attributed to RLJP may be substantially minimized by using a calibrator solution that contains an anion with mobility similar to that of HCO3-.
Eye movement triggered averaging and topographic display techniques indicate the presence of parieto-occipital potentials that precede the rapid eye movements of human REM sleep. Since these potentials have strong similarities with PGO waves in animals, including lateralization according to eye movement (EM) direction, and with waking EM-antecedent potentials in man, this suggests that PGO-like activity both exists in man, and may be functionally related to EM-antecedent potentials in waking. The ability to detect such central potentials opens the possibility of studying REM sleep central physiological structure in a variety of normal and pathological conditions in humans.
Certain common clinical laboratory tests are employed regularly to determine the presence of active necrotizing processes in the liver. These include in particular bilirubin, several enzymes, clotting factors, and serum proteins. We have studied a patient with perihepatic and intrahepatic infection and extensive necrosis, who showed minimal changes in the usual biochemical markers associated with hepatocellular damage. The significance of these findings is discussed.
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This article presents an approach to total documentation of clinical laboratory methods that is practical and comprehensive. Primary reference documents including the bench method, all aspects of instrumentation, calibration, quality control, safety, results, and reporting conventions and back-up research data are entered into a matrix by section. This system has proved to be of great utility particularly in meeting regulatory demands and for the use and orientation of staff technologists.
Latent inhibition (LI) is an attentional process by which animals learn to ignore a stimulus that is repeatedly presented without reinforcement. This ability to tune out a motivationally irrelevant stimulus is disrupted by pharmacological manipulations producing hyperdopaminergic states. In Experiment I, LI was disrupted following five daily administrations of 4 mg/kg d-amphetamine. In Experiment II the disruptive effects of d-amphetamine were eliminated by concomitant administration of chlorpromazine. Experiment III showed that LI could also be disrupted with 1 mg/kg d-amphetamine coupled with dopamine receptor supersensitivity produced by prolonged pretreatment with haloperidol. These data suggest that pharmacological disruption of LI may provide an animal analogue of the defective stimulus filtering thought to characterize at least some forms of schizophrenia.
Antiserum to polyacrylamide has been produced in rabbits. It can be used in a sensitive radioimmunoassay for quantitation of polyacrylamide at very low concentrations. This novel approach to the analysis of a synthetic, biologically inactive, hydrocarbon polymer has potentially widespread implications, for example, in the downstream measurement of flocculating agents used in water purification treatments.
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