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Biomedical subjects

C Weir

Publications and source records attributed to C Weir.

At least 19 recordsLinked to original sources
PubMed2003

Evaluation of an internal positive control for Cryptosporidium and Giardia testing in water samples.

AIMS: An internal positive control for Cryptosporidium and Giardia monitoring was evaluated for use in routine water monitoring quality control. The control, known as ColorSeed C&G (BTF Pty Ltd, Sydney, Australia), is a suspension containing exactly 100 Cryptosporidium oocysts and 100 Giardia cysts that have been modified by attachment of Texas Red to the cell wall, allowing them to be differentiated from unmodified oocysts and cysts. The control enables recovery efficiencies to be determined for every water sample analysed. METHODS AND RESULTS: A total of 494 water samples were seeded with ColorSeed C&G and with unlabelled Cryptosporidium and Giardia and then analysed. Additionally, the robustness of the ColorSeed labelling was challenged with various chemical treatments. Recoveries were significantly lower for the ColorSeed Texas Red labelled Cryptosporidium and Giardia than recoveries of unlabelled Cryptosporidium and Giardia. However, the differences in recoveries were small. On average ColorSeed Cryptosporidium recoveries were 3.3% lower than unlabelled Cryptosporidium, and ColorSeed Giardia recoveries were 4% lower than unlabelled Giardia. CONCLUSIONS: ColorSeed C&G is suitable for use as an internal positive control for routine monitoring of both treated and raw water samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The small differences in recoveries are unlikely to limit the usefulness of ColorSeed C&G as an internal positive control. The ColorSeed labelling was found to be robust after different treatments.

Animals↗
PubMed2000

Developmental differences in understanding of balance scales in the United States and Zimbabwe.

This cross-cultural, developmental study of understanding of the physics of a balance scale involved 2 age groups (5- and 22-year-olds) in 2 countries (the United States and Zimbabwe). A factorial design was used. Each participant solved 6 types of balance scale problems, and the patterns of errors for these problem types were analyzed to determine which rules and concepts the participant used (e.g., whether number of weights was considered). As expected, on average, older participants were more accurate than younger participants, although significant age differences in the Zimbabwean sample were not found for problems solved by weight or distance cues. One finding differing from earlier research was that problems in which the beam balanced were more difficult for all participants. Generally, understanding of the physics of a balance scale appeared fairly similar in the 2 countries. Some cultural practices may account for the findings--in particular, the availability of preschool and age at time of academic specialization in higher education.

Adolescent↗
PubMed2000

An immunoglobulin G1 monoclonal antibody highly specific to the wall of Cryptosporidium oocysts.

The detection of Cryptosporidium oocysts in drinking water is critically dependent on the quality of immunofluorescent reagents. Experiments were performed to develop a method for producing highly specific antibodies to Cryptosporidium oocysts that can be used for water testing. BALB/c mice were immunized with six different antigen preparations and monitored for immunoglobulin G (IgG) and IgM responses to the surface of Cryptosporidium oocysts. One group of mice received purified oocyst walls, a second group received a soluble protein preparation extracted from the outside of the oocyst wall, and the third group received whole inactivated oocysts. Three additional groups were immunized with sequentially prepared oocyst extracts to provide for a comparison of the immune response. Mice injected with the soluble protein extract demonstrated an IgG response to oocysts surface that was not seen in the whole-oocyst group. Mice injected with whole oocysts showed an IgM response only, while mice injected with purified oocyst walls showed little increase in IgM or IgG levels. Of the additional reported preparations only one, BME (2-mercaptoethanol treated), produced a weak IgM response to the oocyst wall. A mouse from the soluble oocyst extract group yielding a high IgG response was utilized to produce a highly specific IgG(1) monoclonal antibody (Cry104) specific to the oocyst surface. Comparative flow cytometric analysis indicated that Cry104 has a higher avidity and specificity to oocysts in water concentrates than other commercially available antibodies.

Animals↗
PubMed2000

Computer needs assessment based on nursing tasks.

The purpose of this paper was to validate the Nurse Task Computer Use (NTCU) scale as a measure of the impact of computer use on tasks performed by nurses. It was expected that evaluation of a computer system by tasks is a better measure of nursing satisfaction. We used four strategies to accomplish validation. Initially, we used taxonomy of nursing interventions developed by Susan Grobe as a basis for identifying tasks. Next, using factor analysis, the results of the NTCU was compared to two validated user satisfaction scales. The third validation strategy consisted of comparing responses to the survey with interview findings for similarity, additional responses, and reoccurring patterns. Finally, findings from the results of the NTCU were compared to the Computers in Medical Care values survey. Results generally supported the validity and reliability of this instrument.

Attitude of Health Personnel↗
PubMed2000

Assessing the implementation process.

A Computerized Patient Record System (CPRS) has many benefits and could improve health care outcomes. Reaping these benefits, however, is dependent on successful implementation of a provider order entry system. The literature supports substantial evidence that even systems that are usable, effective and reliable have not been adopted by the intended users. A successful implementation may be substantially a function of the degree to which the processes of care have changed to adapt to the new system. To ensure successful implementation we suggest monitoring the implementation process itself. The purpose of this paper is to report the methodology we developed for assessing how successfully a provider order entry system is being implemented. We adopt a model of diffusion of information technology developed by Fichman (1994) and expanded by Ash (1997). In this model, diffusion is characterized be three categories, "breadth" (infusion) and "depth" (diffusion) and "quality" (appropriateness of use). In this paper we discuss the typology of diffusion and describe specific measures designed to measure infusion and diffusion of a hospital information system.

Diffusion of Innovation↗
PubMed1998

Myolipoma of the eyelid.

BACKGROUND: This report describes the pathology of a myolipoma which occurred in the eyelid. Myolipoma is a benign hamartomatous tumour in which smooth muscle cells are interspersed with adipocytes. PATIENT DETAILS: An irregular yellowish tumour (30 x 25 mm) with illdefined borders had been present for 50 years in the medial part of the left lower eyelid of a 67-year-old woman. The tumour was excised and studied by conventional histology, immunohistochemistry and transmission electron microscopy. RESULTS: The tumour was formed by bundles of spindle-shaped cells with cigarshaped nuclei intermingled with multiloculated clear cells containing small eccentric nuclei. By immunohistochemistry, positive staining of the spindle cells was restricted to smooth muscle actin and desmin; the clear cells were non-reactive with the immunohistochemical panel, but fat was identified within the cytoplasm. The ultrastructural features of the spindle cells were those of a leiomyoma, while the clear cells were classified as adipocytes. CONCLUSION: This tumour was considered to originate from the media of blood vessels within the tumour.

Actins↗
PubMed1998

The role of problem definitions in understanding age and context effects on strategies for solving everyday problems.

The participants (107 preadolescents, 124 college students, 118 middle-aged adults, and 131 older adults) described 2 everyday problems (1 unconstrained, the other constrained to 1 of 6 domains) that they experienced and their goals and strategies. Problem definitions reflected interpersonal or competence components or both; strategies reflected altering cognitions, actions, or regulating and including others. Age differences in problem definitions were found. For unconstrained-domain problems, age and problem definition were related to strategies; for unconstrained-domain problems age differences in strategies were not found. For constrained-domain problems, strategies related to problem domain and problem definition, with problem definition the better predictor of strategies. The results illustrate the value of individuals' problem definitions for addressing age and context effects on strategies used.

Activities of Daily Living↗
PubMed1998

The need for a thoughtful deployment strategy: evaluating clinicians' perceptions of critical deployment issues.

This paper presents data collected from 899 clinicians across three Department of Veterans Affairs (VA) medical centers where existing terminal-based architecture was being replaced with client-server architecture. Surveys were conducted with physicians (n = 184), nurses (n = 355) and other clinicians (n = 360) gathering user characteristics and their perceptions of five deployment issues (e.g. adequacy of technical and institutional support and perceptions of the soon-to-be-implemented clinical workstation). Mean scores for the five deployment issues for all clinicians indicates perceptions are somewhat neutral. However, when data is analyzed according to job classification, significant (p = 0.05) differences in perceptions were noted among groups of clinicians (e.g., physicians and registered nurses). Results of analyzing data grouped by VA site (n = 3) indicates significant (p = 0.05) differences exist among sites in clinicians' perceptions of the deployment issues. A thoughtful deployment strategy including an in-depth assessment of clinician users by job classification and by location may produce important information, critical to the successful deployment of new technologies, in very large health management institutions.

Attitude to Computers↗
PubMed1998

Prospective study on factors delaying surgery in ruptured abdominal aortic aneurysms.

Delays between rupture, eventual diagnosis and the repair of abdominal aortic aneurysms (AAAs) can significantly affect outcome, but the reasons for such delays in management are not always clear. A prospective study was, therefore, performed on 30 patients with ruptured AAAs. Twenty-three male and seven female patients, mean age 71.3 years, were studied. The general practitioner had made the correct diagnosis in only 38% of cases and the most common misdiagnosis was renal colic (24%). Non-vascular hospital doctors made the correct diagnosis in 55% of cases, but patients with back pain were the most frequently misdiagnosed by both types of doctor. The performance of an ultrasound scan significantly delayed referral to the vascular unit from a median of 0.75 to 2.50 hours and was of little benefit in aiding the diagnosis. In conclusion, the most striking delay factors in the management of ruptured AAAs are the high incidence of misdiagnosis and the lack of benefit of ultrasound scanning.

Aged↗
PubMed1997

Are backward words special for older adults?

Two experiments comparing older and young adults confirmed that Stroop interference from lists of incongruent color words was greater for older adults. Similar age effects were observed when the lists of words were presented in 2 unusual print orientations (upside-down; backward and upside-down). In contrast, no age effect was observed, when participants named colors on backward-word lists, as measured with a percentage interference score that corrected for individual differences in baseline (color patches) naming times. Reading speed failed to account for all the interference effects in these data.

Adolescent↗
PubMed1997

The effects of neonatal jaundice and respiratory complications on learning and habituation in 5- to 11-month-old infants.

The influences of neonatal hyperbilirubinemia and respiratory complications were examined in 5- to 11-month-old infants in two studies. One study focused on habituation performance and the other on contingency learning. In both experiments, three neonatal jaundice conditions (no jaundice history, measured bilirubin, phototherapy) were crossed with two levels of neonatal respiratory risk (no oxygen intervention, oxygen intervention). For low respiratory risk subjects there were increasingly adverse effects for both habituation and learning the more severe the jaundice history. A complex pattern emerged for the high respiratory risk groups. Only for the learning task were the results consistent with a summative effect of neonatal jaundice and respiratory risk factors.

Arousal↗
PubMed1997

Use of Iliad to improve diagnostic performance of nurse practitioner students.

Nurse practitioners (NPs) have dual goals as primary care providers, combining the traditional goals of nursing with extended goals as diagnosticians. Diagnostic reasoning, therefore, is a critical component of NP education. Iliad, a computerized diagnostic reasoning expert system, has been used effectively to teach diagnostic skills to medical students. A pilot study was undertaken to determine the effects of Iliad training on NP students' diagnostic skill performance and to identify technical and instructional issues of implementation. The study found that the use of Iliad improved NP students' diagnostic reasoning, and that the training effects were modified by prior nursing experience. Successful use of Iliad required planning, faculty commitment, and technical support.

Clinical Competence↗
PubMed1996

Facial swelling in giant cell (temporal) arteritis.

Giant cell (temporal) arteritis is a systemic vasculitis of the elderly. Facial swelling is a rare manifestation of the arteritic process. Delay in recognition of the condition can result in profound loss of vision. This report describes a biopsy-proven arteritic patient who developed anterior ischaemic optic neuropathy (AION) following facial swelling. Both arteritic AION and facial swelling responded to high-dose steroid treatment. Facial swelling in giant cell (temporal) arteritis could be an indicator of risk of AION. Intravenous steroid treatment can lead to salvation of useful vision.

Aged↗