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Biomedical subjects

C S Scott

Publications and source records attributed to C S Scott.

At least 37 records · Page 2Linked to original sources
PubMed2000

Information and informatics literacy: skills, timing, and estimates of competence.

BACKGROUND: Computing and biomedical informatics technologies are providing almost instantaneous access to vast amounts of possibly relevant information. Although students are entering medical school with increasingly sophisticated basic technological skills, medical educators must determine what curricular enhancements are needed to prepare learners for the world of electronic information. PURPOSE: The purpose was to examine opinions of academic affairs and informatics administrators, curriculum deans and recently matriculated medical students about prematriculation competence and medical education learning expectations. METHODS: Two surveys were administered: an Information Literacy Survey for curriculum/informatics deans and a Computing Skills Survey for entering medical students. RESULTS: Results highlight differences of opinion about entering competencies. They also indicate that medical school administrators believe that most basic information skills fall within the domain of undergraduate medical education. CONCLUSIONS: Further investigations are needed to determine precise entry-level skills and whether information literacy will increase as a result of rising levels of technical competence.

Computer Literacy↗
PubMed2000

Trichloroethylene and cancer: epidemiologic evidence.

Trichloroethylene is an organic chemical that has been used in dry cleaning, for metal degreasing, and as a solvent for oils and resins. It has been shown to cause liver and kidney cancer in experimental animals. This article reviews over 80 published papers and letters on the cancer epidemiology of people exposed to trichloroethylene. Evidence of excess cancer incidence among occupational cohorts with the most rigorous exposure assessment is found for kidney cancer (relative risk [RR] = 1.7, 95% confidence interval [CI] 1.1-2.7), liver cancer (RR = 1.9, 95% CI(1.0-3.4), and non-Hodgkin's lymphoma (RR = 1.5, 95% CI 0.9-2.3) as well as for cervical cancer, Hodgkin's disease, and multiple myeloma. However, since few studies isolate trichloroethylene exposure, results are likely confounded by exposure to other solvents and other risk factors. Although we believe that solvent exposure causes cancer in humans and that trichloroethylene likely is one of the active agents, we recommend further study to better specify the specific agents that confer this risk and to estimate the magnitude of that risk.

Animals↗
PubMed2000

Modes of action of trichloroethylene for kidney tumorigenesis.

This article focuses on the various models for kidney toxicity due to trichloroethylene (TCE) and its glutathione-dependent metabolites, in particular S-(1,2-dichlorovinyl)-l-cysteine. Areas of controversy regarding the relative importance of metabolic pathways, species differences in toxic responses, rates of generation of reactive metabolites, and dose-dependent phenomena are highlighted. The first section briefly reviews information on the incidence and risk factors of kidney cancer in the general U.S. population. Epidemiological data on incidence of kidney cancer in male workers exposed occupationally to TCE are also summarized. This is contrasted with cancer bioassay data from laboratory animals, that highlights sex and species differences and, consequently, the difficulties in making risk assessments for humans based on animal data. The major section of the article considers proposed modes of action for TCE or its metabolites in kidney, including peroxisome proliferation, alpha(2u)-globulin nephropathy, genotoxicity, and acute and chronic toxicity mechanisms. The latter comprise oxidative stress, alterations in calcium ion homeostasis, mitochondrial dysfunction, protein alkylation, cellular repair processes, and alterations in gene expression and cell proliferation. Finally, the status of risk assessment for TCE based on the kidneys as a target organ and remaining questions and research needs are discussed.

Animals↗
PubMed1999

Morphine pharmacokinetics and pain assessment in premature newborns.

OBJECTIVES: To determine morphine pharmacokinetics in premature neonates varying in postconceptional age (PCA) and evaluate behavioral pain response in relationship to serum morphine concentrations. METHODS: Premature neonates (n = 48), stratified by weeks of PCA (group 1 = 24-27 weeks, group 2 = 28-31 weeks, group 3 = 32-35 weeks, and group 4 = 36-39 weeks) received morphine infusions. Blood samples were drawn at 48, 60, and 72 hours and at discontinuation of morphine, followed by 3 samples obtained during the next 24 hours. Newborns were videotaped during heel lances and restful states, with morphine at steady-state concentrations and without morphine. Pain was assessed by using the Neonatal Facial Coding System (NFCS). Statistical analysis included regression between NFCS score changes from baseline to painful procedure with and without morphine. RESULTS: Morphine clearance for groups 1, 2, 3, and 4 was calculated as 2.27 +/- 1.07, 3.21 +/- 1.57, 4.51 +/- 1.97, and 7.80 +/- 2.67 mL/kg/min, respectively, and correlated with PCA (r = 0.63, P <.001). Pain measured by facial expression was diminished; however, it did not correlate with morphine concentrations. CONCLUSION: Morphine clearance in premature neonates is less than reported, increasing with PCA. Facial activity discloses morphine analgesia; however, it is unrelated to morphine concentrations.

Analgesics, Opioid↗
PubMed1999

The pharmacokinetics of ibuprofen suspension, chewable tablets, and tablets in children with cystic fibrosis.

OBJECTIVES: The objectives of this study were to compare the pharmacokinetic parameters of ibuprofen administered as a suspension, chewable tablet, or tablet in children with cystic fibrosis and to determine the optimal blood sampling times for measuring ibuprofen peak concentrations. STUDY DESIGN: A single oral 20 mg/kg dose of ibuprofen was administered, and blood samples were obtained at 15, 30, 45, 60, 120, 240, and 360 minutes after the dose was administered. Peak plasma concentration (Cmax ), time to peak concentration (Tmax ), and other pharmacokinetic parameters were determined and compared (analysis of variance and analysis of covariance). RESULTS: Thirty-eight children were included (22, 4, and 12 in the suspension, chewable tablet, and tablet groups, respectively). Tmax was the only parameter for which statistical differences were noted (suspension vs tablet, P </=.02). After age and sex were removed as potential confounding variables, Tmax remained statistically different (P </=.001). CONCLUSIONS: A 20 mg/kg dose of ibuprofen suspension is recommended, with blood samples for pharmacokinetic analysis obtained 30, 45, and 60 minutes after the dose is administered. Obtaining the first blood sample 1 hour after dose administration will miss approximately 90% of peak concentrations, increasing the likelihood of overdosing.

Administration, Oral↗
PubMed1999

Microvolume fluorimetry for the determination of absolute CD4 and CD8 lymphocyte counts in patients with HIV: a comparative evaluation.

This study compared CD4 and CD8 lymphocyte counts obtained by microvolume fluorimetry (MVF) with those derived by flow cytometry (FC). Samples from 192 patients with known or suspected HIV were analysed, and the distribution of CD4 counts for these samples ranged from 0 and 1,279/microl, with 142/192 (74%) of the samples having CD4 values of less than 400/microl. Good agreement between FC and MVF CD4 counts was found (MVF = 0.98 x FC + 7.30) although there was a minor constant inter-method bias of approximately +7 cells/microl for the MVF data. For CD8 counts there was a constant bias between the two methods of approximately +23 cells/microl for FC. Most outliers were associated with higher FC CD8 counts. Supplementary analyses showed a high level of agreement between FC and MVF methods for the CD4:CD8 ratios (MVF = 0.98 x FC). This suggests that observed discrepancies between FC and MVF methods were almost certainly a result of the influence of the absolute lymphocyte counts obtained from the haematology analyser. The results confirm that the IMAGN 2000 microvolume fluorimeter system can be used as an alternative to conventional flow cytometry for the enumeration of CD4 and CD8 counts.

CD4 Lymphocyte Count↗
PubMed1998

Simultaneous differentiation and quantitation of erythroblasts and white blood cells on a high throughput clinical haematology analyser.

After the neonatal period, the presence of nucleated red blood cells (NRBC) in peripheral blood is indicative of pathology. Despite the clinical utility of such measurements, automated NRBC counting has hitherto not been available on routine automated blood cell counting analysers. To address this, an automated method for the analysis of NRBC was developed and incorporated into the Abbott Cell Dyn 4000 (CD4000) haematology analyser. The system white blood cell (WBC) reagent was specifically formulated to preserve concomitantly white blood cell (WBC) morphology, rapidly lyse red blood cell and NRBC membranes, and subsequently stain NRBC nuclei with a nucleotide specific fluorochrome dye (Kim et al. 1996a). The fluorochrome itself does not permeabilize the membrane of intact viable white blood cells. The sample is processed by flow cytometry and the signals generated from an argon-ion laser light source are analysed. Axial light loss (AxLL), intermediate angle light scatter (IAS) and red fluorescence (FL3) are used to discriminate between particles of various types. By using these discriminators in a three-dimensional approach, NRBC from a discrete cluster which can easily be separated from leucocytes and enumerated as a distinct cell population during the optical WBC differential analysis. Consequently, accurate absolute WBC counts and differentials can be obtained even in the presence of NRBC. Background 'noise' (both fluorescent and non-fluorescent) from platelets. Howell-Jolly bodies, basophilic stippling, RNA from lysed reticulocytes, and DNA from leucocyte and megakaryocytic fragments are essentially eliminated (Kim et al. 1996b). While the membranes of intact and viable leucocytes remain impermeable to the passage of the fluorochrome stain, leucocytes with damaged membranes are permeable to the dye and generate FL3+ signals. Such cells, which are commonly seen as a consequence of sample ageing as well as in some distinctive pathologies, are identified by the algorithm (using their AxLL signal size) and are labelled as non-viable. Moreover, because non-viable leucocytes are retained in the WBC count and differential analyses, the CD4000 is further able to provide both numerical and graphical data regarding the relative frequency of viable and non-viable components. This additional information can serve as valuable 'decision-drivers' in the laboratory data review process.

Automation↗
PubMed1998

Comparison of morphine requirements for sedation in Down's syndrome and non-Down's patients following paediatric cardiac surgery.

Anaesthetists recognize that children with Down's syndrome require special management in a number of clinical situations. There is a widespread clinical impression that it is difficult to achieve adequate sedation and that, following cardiac surgery, these children require higher doses of morphine and additional sedative agents compared to patients without Down's syndrome. We conducted a retrospective chart review of 16 Down's syndrome and 16 matched non-Down's syndrome children who underwent cardiac surgery between 1984 and 1991. The average dose of morphine (continuous infusion) administered per hour was higher in the Down's syndrome group than in the non-Down's syndrome group. The difference was not statistically or clinically significant until the third postoperative day. Down's syndrome patients were more likely to still be receiving morphine on Day 3 than non-Down's patients (P < 0.05). The Down's syndrome patients were also more likely to receive additional sedatives and skeletal muscle relaxants.

Analgesics, Opioid↗
PubMed1998

Relationship between early clinical exposure and first-year students' attitudes toward medical education.

PURPOSE: To determine whether there is a relationship between early clinical exposure and students' attitudes toward medical education. METHOD: At the end of the spring quarter, 1995, 93 first-year students at the University of Washington School of Medicine were asked to complete a one-page, 15-item questionnaire. The 11 items in the questionnaire's first section assessed the students' attitudes toward medical education; each item was rated on a five-point Likert scale (1 = strongly agree, 5 = strongly disagree). The four items in the second section assessed the students' clinical exposures, including type, frequency, and duration. RESULTS: In all, 86 of the students (92%) returned completed questionnaires. The students' participation in clinical experiences was, overall, much higher than expected. A total of 77 students (90%) reported some form of clinical exposure. The clinical-exposure group was defined as those students who had participated in a preceptorship for at least one academic quarter (a half-day per week in clinic) or who had at least five days of clinical experience. Significance tests revealed that the students in the clinical-exposure group were more satisfied with their medical education than were the other students (p = .009). The students' attitudes toward medical education were generally favorable, regardless of their clinical exposures. However, approximately one fourth of the class expressed discontent with the process of medical education, and 40% indicated they were more cynical than when they had started school. CONCLUSION: The results of this study suggest that early clinical experience may contribute to students' satisfaction with medical education.

Adult↗
PubMed1998

Red cell folate in elderly patients with myelodysplastic syndrome.

During a 7-month period a prospective study of 71 anaemic patients (29 males and 42 females) over the age of 50 was undertaken in order to identify patients with myelodysplastic syndrome (MDS). The mean values of mean corpuscular volume (MCV), serum ferritin, folate, vitamin B12 and red cell folate (RCF) of patients grouped according to the diagnosis were compared to those observed in age-matched blood donors. Forty-four of the 71 elderly patients showed macrocytic anaemia: 21 of them had gastric disease and the remaining 23 MDS. Two further patients with MDS showed microcytic anaemia. The 25 patients diagnosed with MDS were subclassified according to the FAB nomenclature: 9 had a refractory anaemia with excess of blasts and 16 refractory anaemia. The mean values of MCV, serum folate, ferritin, vitamin B12 and RCF were statistically different between patients with macrocytic anaemia due to gastric disease and patients with MDS. Among patients with MDS, the RCF level pathologically high was inversely correlated to the haemoglobin level (r=-0.39; p<0.05). Thus the RCF and serum folate may represent useful parameters for the diagnosis of MDS in elderly anaemic patients.

Aged↗
PubMed1997

Manual and automated methods for the determination of leukocyte counts at extreme low levels: comparative evaluation of the Nageotte chamber and the Abbott Cell Dyn 3500 analyser.

Leukodepleted or leukocyte-poor blood products (fresh-frozen plasma, packed red cell and platelet concentrates in particular) are widely used in current clinical practice. However, because the monitoring of leukodepletion efficiency is generally carried out (if at all) using the labour-intensive and relatively inaccurate manual Nageotte chamber technique, it is clear that any increased demand for leukodepletion monitoring would be difficult, if not impossible, to meet. As the need to identify an automated alternative to the Nageotte technique is important, this study was undertaken to evaluate such a possibility. White blood cells were enumerated in a representative series of filtered and non-filtered human blood components by both microscopic counting in the Nageotte chamber, and with the Abbott CD3500 automated haematology analyser. For the Nageotte estimate, a single analysis was made in accordance with standard procedures, whereas the automated analysis was achieved by making six replicate counts and determining the mean of four replicates after excluding the highest and lowest estimates. To determine linearity limits of the manual and automated procedures, freshly isolated leukocytes were admixed with cell-free plasma-pheresis plasma. Reasonable reproducibility (mean CV 10% for cell counts exceeding 100 cells/microL) and good linearity (r > 0.9) were observed for CD3500 determinations in four separate experiments. The manual and automated measurements also correlated well (r > 0.9) with no obvious inter-method bias for cell counts up to 40 cells/microL although there was some suggestion of lower absolute CD3500 counts in the range 40-130 cells/microL. For the comparative studies with filtered and non-filtered blood products, no significant method bias was seen with 70 individual red cell concentrates, but systematically higher CD3500 white blood cell counts were observed in the series of 68 platelet concentrates (probably due to the presence of platelet clumps). This study concludes that automation of white cell counts in blood products with the CD3500 analyser is feasible for quality control in the preparation of fresh-frozen plasma and red cell concentrates but is limited for the analysis of filtered platelet concentrates.

Automation↗
PubMed1997

Evaluation of the Abbott Cell Dyn 4000 automated fluorescent reticulocyte measurements: comparison with manual, FACScan and Sysmex R1000 methods.

The Abbott Cell Dyn 4000 (CD4000) is the first haematology analyser in which fully-automated reticulocyte measurements can be routinely determined by fluorescence as part of the full blood count. This communication reports the first evaluation of this method which was undertaken by three independent reference laboratories in Belgium, Germany and Italy. A total of 695 different samples was entered into the study which was designed to compare CD4000 reticulocyte information (enumeration and qualitative maturational data) with results determined in parallel with the existing manual (supravital staining) reference procedure, and two semi-automated fluorescent assays (Becton Dickinson FACScan and Sysmex R1000 instruments). These studies revealed good agreement between the CD4000 and the manual procedure, with no inter-method bias. Comparison of CD4000 and FACScan reticulocyte measurements, however, indicated a distinct tendency for the FACScan to give higher reticulocyte estimates than the CD4000. Finally, the comparison of the CD4000 with the Sysmex R1000 showed excellent agreement in the range 0-6% reticulocytes, although there was some inter-method bias in the higher range (> 15%). Analysis of agreement levels between the methods using specific 'clinical decision points' confirmed the tendency for overestimation by the FACScan, in that 58% of the samples with a reticulocytopenia of < 0.5% as defined by the CD4000 gave FACScan results within the normal range (0.5-1.8%). In contrast, there was absolute agreement between the CD4000 and the Sysmex R1000 for all reticulocytopenias. Comparison (195 samples) of instrument fluorescent reticulocyte maturation profiles demonstrated an exponential relationship (r = 0.78) between CD4000 IRF and R1000 HFR (highly fluorescent reticulocyte fraction) values. The suggestion that the CD4000 IRF values includes some of the MFR as well the HFR reticulocyte fraction was confirmed as the correlation between the CD4000 IRF and the Sysmex R1000 MFR plus HFR percentages was linear (r = 0.82). This study confirms a high performance level for the CD4000 automated fluorescent reticulocyte method.

Autoanalysis↗
PubMed1997

Trichloroethylene health risk assessment: a new and improved process.

Trichloroethylene (TCE), an environmental contaminant of National concern, is the focus of a new health risk assessment process incorporating the Proposed Cancer Risk Assessment Guidelines. This paper describes not only how TCE became an environmental problem for the Air Force, but also details the new Risk Assessment process envisioned by the Environmental Protection Agency's (EPA) National Center for Environmental Assessment (NCEA). Insights on epidemiological evaluations, both past and future, and their impact on the cancer classification of TCE are discussed. Examples of how physiologically based pharmacokinetics and dose-response characterization described in the new Cancer Guidelines are applied to TCE are provided. In addition, a variety of modeling techniques are discussed for the development of reference doses (oral exposure) and reference concentrations (inhalation exposures) for TCE. Finally, the role of risk communication is included. This new process provides an example of how interagency (EPA, Department of Defense. Department of Energy) and extramural (industry, academia) partnerships can provide greater gains to the nation, as a whole, than any of the parts on their own.

Animals↗
PubMed1996

Clinical knowledge and skill priorities in substance abuse education: a nursing faculty longitudinal survey.

The aims of this study were to: 1) determine which of 16 substance abuse content areas nursing faculty fellows considered important for their professional growth; 2) determine content areas in which faculty fellows planned to obtain knowledge and skill development during the coming year; and 3) to identify content areas faculty fellows thought undergraduate and/or graduate students should be taught. Questionnaires were mailed to the 43 nursing faculty fellows who were recipients of substance abuse federal training during the 1989-1994 academic years. The response rate was 81%. One and a half years later, 66% responded to the same items on a follow-up survey. The results showed that faculty ratings of knowledge and skill development needs for themselves and their students in nursing were stable over time. Findings can be used to guide faculty and curriculum development in alcohol and other substance abuse.

Curriculum↗
PubMed1995

Influence of laparoscopic and conventional cholecystectomy upon cell-mediated immunity.

Surgery, trauma and anaesthesia induce a state of transient immunosuppression. Laparoscopic cholecystectomy has several well documented clinical advantages over traditional cholecystectomy and provokes a lower acute phase response, thought to be a result of the smaller wound size. The influence of laparoscopic cholecystectomy (21 patients) and conventional open cholecystectomy (13 patients) upon components of the cell-mediated immune system was investigated. Cell-mediated immunity was studied by in vitro assays of T lymphocyte proliferation to different mitogens, and by natural killer cell cytotoxicity using a standard 51Cr release assay. Blood samples were taken before and 24 h after the start of the operation. In the sample taken after operation there was significant depression of T lymphocyte proliferation to phytohaemagglutinin (stimulation index 149.4 versus 33.3, P < 0.002), staphylococcal enterotoxin B (85.2 versus 52.6, P = 0.01) and toxic shock syndrome toxin (48.4 versus 14.8, P = 0.08) in the group of patients who underwent open surgery, but not in the group treated by laparoscopic surgery. There was a small but statistically insignificant decrease of natural killer cell cytotoxicity in both groups of patients. These findings suggest that laparoscopic cholecystectomy causes less depression of cell-mediated immunity than open cholecystectomy.

Adult↗
PubMed1995

A comparison of self-report and chart audit in studying resident physician assessment of cardiac risk factors.

OBJECTIVE: To examine the relationship between resident physicians' perceptions of their preventive cardiology practices and a chart audit assessment of their documented services. DESIGN: A criterion standard comparison of two methods used to assess resident physicians' practices: self-report and chart audit. SETTING: Physician ambulatory care in a residency program. PATIENTS AND OTHER PARTICIPANTS: Coronary artery disease (CAD) risk factor assessment was evaluated by self-report for 72 resident physicians and by chart audit of randomly selected records of 544 of their patients who did not have CAD or a debilitating chronic disease during a one-year period. INTERVENTION: Measurements of the residents' perceived CAD risk factor assessment practice by self-report, and chart audit assessments of their recorded care. MAIN OUTCOME: The relationship between self-reported and chart audit assessments of CAD risk factors. RESULTS: Chart audit assessment of CAD risk factor management was highly significantly (p < 0.01) lower than self-reported behaviors for evaluation of cigarette smoking, diet, physical activity, stress, plasma cholesterol, blood pressure, and body weight/obesity. CONCLUSIONS: Three different interpretations of these findings are apparent. 1) Physician self-report is a poor tool for the measurement of clinical behavior, and therefore research of physician behavior should not rely solely on self-reported data; 2) physicians' chart recording of their clinical practice is insufficient to reflect actual care; or 3) neither is an accurate measure of actual practice.

Clinical Competence↗