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At least 253 records · Page 14Linked to original sources

PubMed2005

AB-plot assisted determination of fluorophore mixtures in a fluorescence lifetime microscope using spectra or quenchers.

Most treatments of frequency domain lifetime measurements indicate that a set of measurements must be made at multiple frequencies in order to determine the lifetimes of the components in a mixture. Although this is the case in general, under special conditions, single-frequency data can resolve multiple lifetimes. Here, data are presented showing several approaches to determining fluorescence lifetimes in two-component mixtures using single-frequency data. Common to all of the procedures presented is exploitation of variations in the relative contributions of a particular fluorophore to the total fluorescence from a mixture of fluorophores. This variation can be produced intentionally by observing a number of samples which contain different relative amounts of the fluorophores. It can be produced fortuitously by observing spatial variations in a mixture of fluorophores in a specimen or set of specimens observed with a lifetime imaging system. It can also be produced by examination of the lifetime spectrum obtained from a fluorophore mixture or by varying the concentration of a quencher in a fluorophore mixture, in which the two fluorophores have different rate constants for quenching. In many instances, the set of approaches presented here will be unsuitable for examination of arbitrary samples of unknown composition for which the multifrequency approach should be used. However, measurements produced using single-frequency methods may be applied to good effect for controlled experiments having defined fluorophores or sets of fluorophores, particularly in the case of biological lifetime imaging studies.

Journal Article↗

PubMed2005

Navigating the information technology highway: computer solutions to reduce errors and enhance patient safety.

Standardized, seamless, integrated information technology in the health-care environment used with other industry tools can markedly decrease preventable errors or adverse events and increase patient safety. According to an Institute of Medicine (IOM) report released in 1999, preventable errors have caused between 44,000 and 98,000 deaths per year. Following the report, President Bill Clinton requested that the Agency of Healthcare Research and Quality, a government agency, look into the issue and fund, at the local or state level, processes that can reduce errors. Funding subsequently was made available for research that utilizes best practice tools in clinical practice to increase patient safety. The Joint Commission on Accreditation of Healthcare Organization has placed a great deal of emphasis on strategies to reduce patient identification errors. Fragmented systems tout the individual as well as enhanced safety applications. These applications, however, are related to prevention in specific conditions and in specific health-care settings. Systems are not integrated with common reference data and common terminology aggregated at a regional or national level to provide access to patient safety risks for timely interventions before errors and adverse events occur. Standardized integrated patient care information systems are not available either on a regional or on a national level. This article examines tangible options to increase patient safety through improved state-of-the-art tools that can be incorporated into the health-care system to prevent errors.

Accreditation↗

PubMed1994

Recombinant alpha 2a interferon and polycythemia vera: clinical results and biological evaluation by means of Fourier-transform infrared microspectroscopy.

Polycythemia vera (PV) is a chronic myeloproliferative disease. The use of recombinant alpha 2a Interferon (IFN) therapy in this disease is a novel approach. We applied Fourier-transform infrared microspectroscopy (FT-IR-M) to investigate the behavior and therapeutic responsiveness of PV patients treated with IFN. A spectroscopic parameter (A1/A2) was used, corresponding to the ratio of the integrated areas of the bands at 1080 cm-1 and at 1540 cm-1 due to nucleic acids and proteic components, respectively, calculated on the spectra of single megakaryocytes (MKs). In previous studies, we have pointed out that MKs in PV have a surprisingly strong myeloproliferative impulse when compared to MKs from other chronic myeloproliferative diseases. Nine patients out of the 11 studied exhibited a satisfactory responsiveness to the IFN treatment. Ten patients were evaluated by the A1/A2 parameter. In 8 of these, a good agreement was seen between this parameter and the laboratory data commonly used for the assessment of this disease. The infrared parameter, which we propose, proves to be an original, reliable method for the evaluation of recombinant alpha 2a IFN responsiveness in this disease.

Blood Cell Count↗

PubMed2006

Tooth surface loss in adult subjects attending a university dental clinic in Trinidad.

OBJECTIVES: To determine the prevalence of tooth surface loss (TSL) in a sample of subjects attending a university dental clinic in Trinidad and to investigate the relationship to tooth brushing, medical history, parafunction and dietary habits. DESIGN: Tooth surface loss was measured clinically by the index used in the 1998 UK, Adult Dental Health Survey. SETTING: Trinidad, West Indies. PARTICIPANTS: Convenience sample of adult subjects attending The University of the West Indies Dental School Polyclinic, Mount Hope. METHODS: A questionnaire was administered and tooth surface loss measured clinically. MAIN OUTCOME MEASURES: mild, moderate and severe tooth surface loss. RESULTS: 155 subjects were examined (mean age 40.6 years) of whom 72% had some degree of TSL with the majority (52%), exhibiting mild, 16% with moderate and 4% with severe TSL. There were associations found between TSL and age (OR=3.14), reflux (OR=1.37), parafunction (OR=1.06), weekly consumption of citrus fruits (OR=1.31) and soft drinks (OR=1.78), daily consumption of alcohol (OR=1.40) and a vegetarian diet (OR=2.79). CONCLUSIONS: Tooth surface loss in this Trinidadian population group appears to be common. Data supports an association between TSL and age, reflux parafunction and certain dietary patterns.

Adolescent↗

PubMed1996

The design and analysis of social-interaction research.

Static models of interacting persons measured at the interval level are reviewed. A discussion of the fundamental sources of variance and key design decisions in social-interaction research is presented. Outlined are the basic designs for social-interaction research and their proper analysis. Multilevel modeling is likely to become the most common data analysis method. Critical issues unique to social-interaction research are examined, particularly the effect of the partner on the interaction actor. Finally, illustrations of analyses from four extended examples are presented.

Adult↗

PubMed2002

Assessment of functioning and disability after ischemic stroke.

BACKGROUND AND PURPOSE: Functioning and disability after ischemic stroke are clinically meaningful and of major relevance to patients. Despite many instruments available to assess these outcomes, little is known about their interrelation and predictive factors. METHODS: We prospectively identified 4264 patients with acute ischemic stroke from 30 hospitals in Germany during a 1-year period between 1998 and 1999 and registered them in a common data bank. The patients were centrally followed up via telephone interview after 100 days and 1 year to assess various scales such as the Barthel Index (BI), modified Rankin Scale (MRS), extended Barthel Index (EBI), Short Form-36 Physical Functioning (SF-36 PF), and Center for Epidemiologic Studies-Depression short form (CES-D). RESULTS: Outcome status could be assessed in 67.2% of patients 100 days after hospital admission. Of these, 13.9% had died, 53.7% had regained functional independence (BI <95), 46.3% had no or mild residual symptoms (MRS < or =1), and 44.6% had no higher cognitive deficits on the EBI. Of the patients who personally answered the follow-up questions, 67% had no major physical disability (SF-36 PF <60), and 32.9% reported symptoms classified as depression (CES-D > or =10). The high percentage of patients reaching the maximum score (ceiling effect) in the BI was less pronounced in the MRS and SF-36 PF. The predictive factors for dichotomized outcomes on each scale were similar for adverse functioning and disability but varied considerably for depression. CONCLUSIONS: To avoid ceiling effects in outcome distribution of patients treated in specialized stroke centers, the MRS and SF-36 PF instruments are preferable to the BI. Parametric use of the SF-36 PF could further improve outcome measurement by considering individual treatment effects.

Aged↗

PubMedDate not supplied

The assessment of work-related activities and limitations in knee disorders.

The success of knee treatment programs and surgery must be assessed, in part, by both the ability to return patients to work and the documentation of any work-related limitations. Existing occupational rating scales do not rate, in a valid manner, the effect of altered knee function on work activities. We performed a prospective randomized clinical trial in which two different occupational rating systems were tested on 50 patients. One system used job titles and an arbitrary numeric scale for rating occupations; the other used specific criteria for rating job functions according to the intensity, frequency, and duration of certain tasks. The results showed that an effective and valid rating format should consist of five specific objectives: 1) evaluation of different knee functions that typically occur in the work environment; 2) evaluation of work activities separately from sports activities; 3) detection of patients who may have remained at an occupation but who have significantly modified work activities because of knee symptoms; 4) identification of patients who continue to work despite experiencing moderate to severe symptoms; and 5) identification of patients whose work activities decrease because of nonknee-related factors. Furthermore, the results showed that an effective rating system should identify common data reduction errors that can bias the results in analyzing knee-related occupational limitations. The rating system developed circumvents the bias introduced by these anomalies. This system, if adopted by other researchers, would allow for the comparison of treatment results among studies.

Disability Evaluation↗

PubMed1993

The Boston Teacher Questionnaire. 1. Definition of syndromes.

To obtain information about the academic function of 9-year-old children from their school teachers, we created a short, forced-choice questionnaire that asked about the child's knowledge and use of arithmetic tables, reading, spelling, persistence at tasks, flexibility of approach, ability to function independently, distractibility, daydreaming, impulsivity and overexcitability, hyperactivity, and ability to follow simple and sequential directions. Questionnaires were collected from the teachers of 3451 white children whose mothers had enrolled in the National Collaborative Perinatal Project. Six syndromes in girls and five in boys were identified by both cluster and factor analyses of these data. Common to both sexes were five syndromes we labeled arithmetic, tasks (ie, impersistent/dependent/inflexible), reading, attention, and hyperactive. A syndrome characterized by difficulty following directions was seen in girls only. The prevalence of these syndromes ranged from a low for hyperactivity of 2.3 per 100 girls to a high for the attention syndrome of 27.6 per 100 boys. The congruent results obtained with clustering and factor analysis, and the agreement between the observed prevalence of syndromes and prior expectations suggests that the Boston Teacher Questionnaire, as this instrument is called, identifies learning problems in 9-year-old children.

Attention Deficit Disorder with Hyperactivity↗

PubMedDate not supplied

Recent developments in information management for primary and community health services.

While health services provided outside the hospital environment are utilised by the majority of the community, until recently there has been little interest in developing a standard approach to information management in community health settings. With greater accountability for health services expected in the future, State and Federal governments have begun to set the necessary standards by the design of a common data model and data definitions for Primary and Community Health Services. This model will affect the manner in which the National Health Data Dictionary develops--from a primarily institution-based document to a broader approach which encompasses non-institutional care. Two new high level concepts have been introduced: "issue" and "activity". Four States have also formed a consortium to design and implement an information management system for Community Health Services. This necessitates adoption of standard classification systems which could be applied in this environment, especially to the two new high level concepts. This paper outlines recent developments in information management for Community Health and provides a brief summary of available classification systems.

Ambulatory Care Information Systems↗

PubMed2006

An informatics model for tissue banks--lessons learned from the Cooperative Prostate Cancer Tissue Resource.

BACKGROUND: Advances in molecular biology and growing requirements from biomarker validation studies have generated a need for tissue banks to provide quality-controlled tissue samples with standardized clinical annotation. The NCI Cooperative Prostate Cancer Tissue Resource (CPCTR) is a distributed tissue bank that comprises four academic centers and provides thousands of clinically annotated prostate cancer specimens to researchers. Here we describe the CPCTR information management system architecture, common data element (CDE) development, query interfaces, data curation, and quality control. METHODS: Data managers review the medical records to collect and continuously update information for the 145 clinical, pathological and inventorial CDEs that the Resource maintains for each case. An Access-based data entry tool provides de-identification and a standard communication mechanism between each group and a central CPCTR database. Standardized automated quality control audits have been implemented. Centrally, an Oracle database has web interfaces allowing multiple user-types, including the general public, to mine de-identified information from all of the sites with three levels of specificity and granularity as well as to request tissues through a formal letter of intent. RESULTS: Since July 2003, CPCTR has offered over 6,000 cases (38,000 blocks) of highly characterized prostate cancer biospecimens, including several tissue microarrays (TMA). The Resource developed a website with interfaces for the general public as well as researchers and internal members. These user groups have utilized the web-tools for public query of summary data on the cases that were available, to prepare requests, and to receive tissues. As of December 2005, the Resource received over 130 tissue requests, of which 45 have been reviewed, approved and filled. Additionally, the Resource implemented the TMA Data Exchange Specification in its TMA program and created a computer program for calculating PSA recurrence. CONCLUSION: Building a biorepository infrastructure that meets today's research needs involves time and input of many individuals from diverse disciplines. The CPCTR can provide large volumes of carefully annotated prostate tissue for research initiatives such as Specialized Programs of Research Excellence (SPOREs) and for biomarker validation studies and its experience can help development of collaborative, large scale, virtual tissue banks in other organ systems.

Databases as Topic↗

PubMed1987

The effects of distance from primary treatment centers on survival among patients with multiple myeloma.

Twenty-one comprehensive cancer centers participated in a national reporting system of common data items, recording information on all patients seen between 1977 and 1982. There were 240,531 patients who had data abstracted. This report describes 1,479 patients with multiple myeloma. Parameters that may effect the type of treatment given during the initial episode of therapy in the center and the effect of these characteristics on survival were studied. In the univariate analysis, age, treatment, and distance traveled to the center were statistically associated with survival. In a multivariate analysis adjusting for potentially confounding covariates, blacks survive better than whites and the effects of sex and socioeconomic status (SES) on survival approach significance. Survival consistently improved with increasing distance traveled to treatment centers. This may be a serious confounding variable in assessing the results by both single and multiinstitution clinical trials.

Adult↗

PubMed2002

A teaching method for multicultural assessment: psychological report contents and cultural competence.

An earlier training model emphasized systematic feedback on accuracy of concepts contained in student assessment reports prepared with common data sets from standard tests. This feedback resulted in consistent increments in concept agreements between reports prepared by students and more experienced assessors. This model was applied in courses with multicultural students by contrasting standard and multicultural assessment and using data sets from multicultural assessees. These students experienced greater difficulty in demonstrating consistent increments of agreement in report concepts due to uneven knowledge of specific cultures, inapplicability of available norms, and interpretation issues. The effectiveness of combining standard and multicultural training should be compared with conventional standard training followed by culturally focused specialized assessment courses.

Adult↗

PubMed1982

A co-operative study on the clinical value of dynamic renal scanning with deconvolution analysis.

An international project was set up to study the clinical usefulness of intrarenal transit times derived from the renogram by deconvolution. A common data sheet, to collect clinical, biochemical, radiological and isotopic information, was completed by the centres. Five hundred and ninety-one patients were studied and the results analysed. The mean transit time (MTT) in normal kidneys was found to be 3.6 +/- 1.1 min. If the MTT is greater than 7.6 min, a kidney is likely to be obstructed. In vesico-ureteric reflux, the transit times are prolonged, but they are normal in infection, hypertension, parenchymal disease and minimally irradiated kidneys. In transplantation, when the kidney is normal, the transit times are shorter than in the natural kidney; in acute rejection, transit time are prolonged.

Adult↗

PubMed1999

In vitro wear device for determining posterior composite wear.

BACKGROUND: An in vitro device has been developed to predict the long-term clinical performance of posterior composite resins. In contrast to most systems, it is based on three-bodied wear--the type of wear generated by food bolus during mastication. METHODS: The authors wear-tested two groups of materials that included posterior composite resins, a castable ceramic, an amalgam and an unsalinated composite resin. After the wear-testing device concluded 400,000 cycles, the authors evaluated replicas of restoration surfaces for material loss. They used scanning electron microscopy to determine the mechanism of wear. RESULTS: The authors detected considerable differences in wear among the various materials included in the study. All of the differences, however, fell within the range of results obtained from the positive and negative controls (unsilanated composite resin and ceramic, respectively). A comparison of the in vitro wear values with the wear values obtained from a series of ongoing clinical studies at the same institution revealed a high level of agreement. Furthermore, replicas of the laboratory-tested composite resin samples revealed the same wear patterns as those generated from clinical restorations. The variation coefficients for the in vitro data generally did not exceed 5 percent, whereas those for the clinical data commonly averaged 20 percent. CONCLUSIONS: Based on the results of this study, the authors conclude that the in vitro testing device is reliably capable of predicting long-term clinical wear values. The results obtained after 92 hours of wear testing correlated closely with those obtained after three years of clinical testing. CLINICAL IMPLICATIONS: Long-term clinical studies are both time-consuming and expensive. Reliable in vitro wear-testing techniques allow manufacturers to develop or modify composite resin systems in considerably shorter periods.

Analysis of Variance↗

PubMed2005

Characteristics of women undergoing repeat induced abortion.

BACKGROUND: Although repeat induced abortion is common, data concerning characteristics of women undergoing this procedure are lacking. We conducted this study to identify the characteristics, including history of physical abuse by a male partner and history of sexual abuse, of women who present for repeat induced abortion. METHODS: We surveyed a consecutive series of women presenting for initial or repeat pregnancy termination to a regional provider of abortion services for a wide geographic area in southwestern Ontario between August 1998 and May 1999. Self-reported demographic characteristics, attitudes and practices regarding contraception, history of relationship violence, history of sexual abuse or coercion, and related variables were assessed as potential correlates of repeat induced abortion. We used chi2 tests for linear trend to examine characteristics of women undergoing a first, second, or third or subsequent abortion. We analyzed significant correlates of repeat abortion using stepwise multivariate multinomial logistic regression to identify factors uniquely associated with repeat abortion. RESULTS: Of the 1221 women approached, 1145 (93.8%) consented to participate. Data regarding first versus repeat abortion were available for 1127 women. A total of 68.2%, 23.1% and 8.7% of the women were seeking a first, second, or third or subsequent abortion respectively. Adjusted odds ratios for undergoing repeat versus a first abortion increased significantly with increased age (second abortion: 1.08, 95% confidence interval [CI] 1.04-1.09; third or subsequent abortion: 1.11, 95% CI 1.07-1.15), oral contraceptive use at the time of conception (second abortion: 2.17, 95% CI 1.52-3.09; third or subsequent abortion: 2.60, 95% CI 1.51-4.46), history of physical abuse by a male partner (second abortion: 2.04, 95% CI 1.39-3.01; third or subsequent abortion: 2.78, 95% CI 1.62-4.79), history of sexual abuse or violence (second abortion: 1.58, 95% CI 1.11-2.25; third or subsequent abortion: 2.53, 95% CI 1.50-4.28), history of sexually transmitted disease (second abortion: 1.50, 95% CI 0.98-2.29; third or subsequent abortion: 2.26, 95% CI 1.28-4.02) and being born outside Canada (second abortion: 1.83, 95% CI 1.19-2.79; third or subsequent abortion: 1.75, 95% CI 0.90-3.41). INTERPRETATION: Among other factors, a history of physical or sexual abuse was associated with repeat induced abortion. Presentation for repeat abortion may be an important indication to screen for a current or past history of relationship violence and sexual abuse.

Abortion Applicants↗

PubMedDate not supplied

Introducing a clinical-behavioural scoring system for children's oral hygiene.

OBJECTIVES: Developing and testing a clinical-behavioural scoring system for assessing children's oral hygiene. MATERIALS AND METHODS: One clinical variable (the presence of dental plaque, measured using Silness and Loe's index) and one behavioural variable (self-reported tooth brushing frequency) were combined into secondary data analysis of research databases for 3-6-year-olds and 6-13-year-olds in a Mexican community. The combined scoring is an ordinal scale that depicts suitable, moderate and inadequate hygiene. Blinded dental examiners also collected dmft/DMFT data in standardised conditions. Data was analysed with Spearman's rho, Kruskall-Wallis, non-parametric tests for trends and Pearson's chi2 tests. RESULTS: 1303 children aged 3-6 years old and 1644 children aged 6-13 years old participated in the study. Clear relationships existed between the combined scoring system and dmft (p < 0.01) and between the scoring system and DMFT (p < 0.01), suggesting that the combined clinical-behavioural scoring system is a reasonably accurate measurement of the relationship between caries experience and oral hygiene in children in the given setting. CONCLUSIONS: The combined clinical-behavioural scoring system is a simple, easy-to-use tool that incorporates clinical and behavioural data commonly found in dental systems. Whether the clinical-behavioural scoring system can be generalised remains to be established.

Adolescent↗

PubMed2002

An introduction to Rasch measurement for scale development and person assessment.

This article: a) outlines some of the limitations of True Score Theory, b) discusses some advantages of Rasch measurement, and c) compares the results of Rasch and factor analytic techniques applied to a common data set. Using a mail survey, 206 female members of a national nursing association completed Ryckman's (1982) Perceived Physical Ability Scale. Exploratory factor analysis identified one factor with a Cronbach alpha of .78. Rasch fit statistics also identified one dimension with a person reliability of .76. Rasch methods were also used to investigate the rating scale functioning, additional construct validity issues, and person diagnosis. Discrepancies between the two estimates of internal consistency are discussed and differences in the utility of the two methodologies are reviewed.

Adult↗

PubMed2004

Multimodal classical conditioning of fear: contributions of direct, observational, and verbal experiences to current fears.

The authors propose that a multimodal classical conditioning model be considered when clinicians or clinical researchers study the etiology of fears and anxieties learned by human beings. They argue that fears can be built through the combined effects of direct, observed, and verbally presented classical conditioning trials. Multimodal classical conditioning is offered as an alternative to the three pathways to fear argument prominent in the human fear literature. In contrast to the three pathways position, the authors present theoretical arguments for why "learning by observation" and "learning through the receipt of verbal information" should be considered classical conditioning through observational and verbal modes. The paper includes a demonstration of how data, commonly collected in research on the three pathways to fear, would be studied differently using a multimodal classical conditioning perspective. Finally, the authors discuss implications for assessment, treatment, and prevention of learned fears in humans.

Adolescent↗