Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Structural validation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28Linked to original sources
PubMed2000

Familial aggregation of psychotic symptoms in Huntington's disease.

OBJECTIVE: The mutation responsible for Huntington's disease is an elongated and unstable trinucleotide (CAG) repeat on the short arm of chromosome 4. Psychotic symptoms are more common in patients with Huntington's disease than in the general population. This study explored the relationship of psychosis in Huntington's disease patients with the number of CAG repeats and family history of psychosis. METHOD: Forty-four patients with Huntington's disease, 22 with and 22 without psychotic symptoms, were recruited from two university-affiliated medical genetics clinics in Seattle and Vancouver, B.C. Psychiatric assessments of the subjects were made through chart review, and diagnoses were validated by structured interviews in a subset of patients. The demographic and clinical characteristics of the psychotic and nonpsychotic patients were compared. RESULTS: The two groups did not differ in demographic and clinical characteristics, except that subjects with psychosis were significantly more likely than nonpsychotic subjects to have a first-degree relative with psychosis. In eight of nine families in which Huntington's disease probands with psychosis had a first-degree relative with psychosis, the relative's psychosis co-occurred with Huntington's disease. In the Huntington's disease probands with psychosis, the onset of psychosis correlated with the onset of the neurological symptoms of Huntington's disease, and the age at onset of psychosis was lower in probands with a higher number of CAG repeats. CONCLUSIONS: Patients with Huntington's disease and psychotic symptoms may have a familial predisposition to develop psychosis. This finding suggests that other genetic factors may influence susceptibility to a particular phenotype precipitated by CAG expansion in the Huntington's disease gene.

Adolescent↗
PubMed1991

Assessment and diagnosis of borderline personality disorder.

Borderline personality disorder is common in treatment settings and may be so in the general population. In this guide to assessment strategies for diagnosing borderline personality disorder, the authors discuss the reliability and validity of structured interviews and self-report instruments and suggest the use of a self-report questionnaire as a cost-effective screening test. Assessment problems, such as the need for longitudinal observation, are reviewed. Essential features of the recommended diagnostic approach include clarity about the diagnostic concept, consideration of the full range of diagnostic criteria, incorporation of recently developed diagnostic methodologies, care in distinguishing personality disorders from comorbid axis I syndromes, and complete assessment of the full range of axis II disorders.

Borderline Personality Disorder↗
PubMed2000

Production of diagnostic rules from a neurotologic database with decision trees.

A decision tree is an artificial intelligence program that is adaptive and is closely related to a neural network, but can handle missing or nondecisive data in decision-making. Data on patients with Meniere's disease, vestibular schwannoma, traumatic vertigo, sudden deafness, benign paroxysmal positional vertigo, and vestibular neuritis were retrieved from the database of the otoneurologic expert system ONE for the development and testing of the accuracy of decision trees in the diagnostic workup. Decision trees were constructed separately for each disease. The accuracies of the best decision trees were 94%, 95%, 99%, 99%, 100%, and 100% for the respective diseases. The most important questions concerned the presence of vertigo, hearing loss, and tinnitus; duration of vertigo; frequency of vertigo attacks; severity of rotational vertigo; onset and type of hearing loss; and occurrence of head injury in relation to the timing of onset of vertigo. Meniere's disease was the most difficult to classify correctly. The validity and structure of the decision trees are easily comprehended and can be used outside the expert system.

Databases, Factual↗
PubMed1999

Discovering diagnostic rules from a neurotologic database with genetic algorithms.

Data on patients with Meniere's disease, vestibular schwannoma, traumatic vertigo, sudden deafness, benign paroxysmal positional vertigo, or vestibular neuritis were retrieved from the database of otoneurologic expert system ONE for the development and testing of a genetic algorithm (GA). The accuracy of the diagnostic rules in solving the test cases was 81%, 91%, 92%, 95%, 96%, and 98% for the respective diseases. The best rules retrieved from the GA were described by a set of questions with the most likely answers. The most important questions concerned the duration of hearing loss and the occurrence of head injury. The validity and structure of the rules created with a GA can be analyzed in detail. For rare diseases, some other reasoning process can be used, for example, case-based reasoning.

Algorithms↗
PubMed2002

The impact of latitude on the prevalence of seasonal depression.

BACKGROUND: This study sought to determine whether the prevalence of the seasonal subtype of major depression (SAD) in the community varied as a function of latitude. METHODS: Random telephone numbers were generated across 8 degrees of latitude (41.5 degrees N to 49.5 degrees N) for the province of Ontario. Eight strata of 1 degree each were sampled equally throughout a 12-month period. Using a validated and structured diagnostic interview, we interviewed by telephone respondents over 20 years of age who had lived in the region for 3 years or more. We evaluated patterns of symptom change across seasons to establish a diagnosis of SAD according to DSM-IV criteria. RESULTS: Of the 2078 households that were assessed for eligibility, 1605 (77%) completed the interview. The crude prevalence of lifetime SAD was 2.6% (95% CI, 1.9 to 3.5). There was no impact of latitude on prevalence of either major depression or the seasonal subtype across the 8 strata, although the global measure of the severity of seasonal change in mood was significantly negatively correlated with latitude. CONCLUSIONS: SAD is a common subtype of major depression in Ontario, but there is no evidence to support an increase in prevalence with increasing latitude.

Adult↗
PubMed1999

The Rorschach Inkblot Test: a case of overstatement?

In the 1940s, inflated claims were often made regarding the Rorschach Inkblot Test. Over half a century later, overstatements regarding the test are still common. The present article identifies problems with the Rorschach regarding norms, cultural sensitivity, interrater reliability, test-retest reliability, validity, factor structure, and accessibility of supporting studies. Contrary to overstated claims made on behalf of the Rorschach, the test continues to be a highly problematic instrument from a psychometric standpoint.

Adult↗
PubMed2003

Psychometric analysis of the Psychopathic Personality Inventory (PPI) with female inmates.

This study evaluated the reliability, internal structure, and validity of the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996) among female inmates (n = 153) housed at a multilevel prison facility. Findings from this research suggested both strengths and weaknesses associated with PPI psychopathy assessment. Reliability of the PPI was supported by internal consistency analyses of scale and subscale item sets, and test-retest reliability was supported by findings obtained with a subsample (n = 36) retested an average of 49 days after initial test administration. Validity of the PPI total score was also supported by moderate to very high correlations with other self-report measures of psychopathy. Relative weaknesses of the PPI were evident by the low or negative associations among many of the PPI subscales, moderate associations that PPI total scores demonstrated with response set indexes, and the similarity of PPI total scores among female inmates and undergraduates. Findings from this research are considered in relation to possible sex differences in the expression of psychopathy and challenges associated with the assessment of the psychopathy construct with self-report methods.

Adult↗
PubMed1993

The product of the Drosophila segment polarity gene armadillo is part of a multi-protein complex resembling the vertebrate adherens junction.

Sequence similarity between the Drosophila segment polarity protein Armadillo and the vertebrate adherens junction protein beta-catenin raised the possibility that adherens junctions function in transduction of intercellular signals like that mediated by Wingless/Wnt-1. To substantiate the sequence similarity, properties of Armadillo were evaluated for consistency with a junctional role. Armadillo is part of a membrane-associated complex. This complex includes Armadillo, a glycoprotein similar in size to vertebrate cadherins, and the Drosophila homolog of alpha-catenin. Armadillo co-localizes with junctions that resemble vertebrate adherens junctions in morphology and position. These results suggest that Drosophila and vertebrate adherens junctions are structurally similar, validating use of Armadillo and its associated proteins as a model for vertebrate adherens junctions.

Animals↗
PubMed2003

Insights into the biochemical and genetic basis of glucokinase activation from naturally occurring hypoglycemia mutations.

Glucokinase (GCK) is a key regulatory enzyme in the pancreatic beta-cell and catalyzes the rate-limiting step for beta-cell glucose metabolism. We report two novel GCK mutations (T65I and W99R) that have arisen de novo in two families with familial hypoglycemia. Insulin levels, although inappropriately high for the degree of hypoglycemia, remain regulated by fluctuations in glycemia, and pancreatic histology was normal. These mutations are within the recently identified heterotropic allosteric activator site in the theoretical model of human beta-cell glucokinase. Functional analysis of the purified recombinant glutathionyl S-transferase fusion proteins of T65I and W99R GCK revealed that the kinetic changes result in a relative increased activity index (a measure of the enzyme's phosphorylating potential) of 9.81 and 6.36, respectively, compared with wild-type. The predicted thresholds for glucose-stimulated insulin release using mathematical modeling were 3.1 (T65I) and 2.8 (W99R) mmol/l, which were in line with the patients' fasting glucose. In conclusion, we have identified two novel spontaneous GCK-activating mutations whose clinical phenotype clearly differs from mutations in ATP-sensitive K(+) channel genes. In vitro studies confirm the validity of structural and functional models of GCK and the putative allosteric activator site, which is a potential drug target for the treatment of type 2 diabetes.

Adolescent↗
PubMed1987

Analysis of individual, intraspecific and interspecific variability in quantitative parameters of caprine tooth enamel structure.

Qualitative and quantitative features of mammalian tooth enamel structure are increasingly being used in taxonomic and phylogenetic analyses, although the variability shown by these traits has not received adequate consideration. This study evaluates the variability displayed by nine quantitative parameters in deep, intermediate, and superficial molar enamel in the closely related bovids Ovis aries and Capra hircus. These parameters are assessed in terms of the absolute and/or relative variability evinced at a given depth within a single individual, among conspecific individuals, and between species samples. The degrees of relative variability expressed at a given depth are comparable among conspecific individuals and between taxonomic samples. Nevertheless, in many instances, there are significant differences in absolute variability amongst individuals. Also, in four parameters for which individual specimen averages could be calculated, the equality of these means among conspecifics can be rejected. Variability is not equivalent at different enamel depths. The null hypothesis of equality of individual, conspecific variances can be rejected most commonly for parameters measured in deep and superficial enamel, and coefficients of variation also tend to be higher for deep and superficial enamel than for enamel of intermediate depth. The greater variability displayed by deep and especially superficial enamel may be related to the initial onset and the terminal phase of ameloblastic secretory activity. Taxonomic and phylogenetic analyses that utilize quantitative data on enamel structure are valid only if comparisons have been made at equivalent enamel depths.

Ameloblasts↗
PubMed2003

Psychometric evaluation of the alcohol use disorders identification test and short drug abuse screening test with psychiatric patients in India.

BACKGROUND: The Alcohol Use Disorders Identification Test (AUDIT) and the short Drug Abuse Screening Test (DAST-10) are brief self-report screens for alcohol and drug problems that have not been evaluated for use with psychiatric patients in developing countries. This study was designed to evaluate the factor structure, reliability, validity, and utility of the AUDIT and the DAST-10 in an Indian psychiatric hospital. METHOD: Consecutive inpatient admissions from April to December 2001 were sampled. Patients were diagnosed with substance use disorders or psychiatric disorders according to ICD-10 criteria. All patients completed both the AUDIT and the DAST-10 during their intake evaluation. RESULTS: Of the 2286 admissions to the hospital, 1349 were enrolled in the study (30% women); 361 patients (27%) had primary substance use disorders and 988 patients (73%) had primary psychiatric disorders. Both the AUDIT and the DAST-10 were unidimensional and internally consistent. Total scores significantly differentiated the subsamples with primary substance use from those with primary psychiatric disorders (p <.0001). Using cutoff scores of >/= 8 on the AUDIT and >/= 3 on the DAST-10, only 10% (N = 100) of the psychiatric subsample exceeded either cutoff, whereas 99% (N = 358) of the addiction treatment subsample exceeded 1 or both cutoffs. Within the psychiatric subsample, 77% (N = 65) of the patients who were identified as high risk on the AUDIT did not receive an additional alcohol use disorder diagnosis at discharge, and 59% (N = 16) of those identified as high risk on the DAST-10 did not receive an additional discharge diagnosis of drug use disorder. CONCLUSION: The AUDIT and the DAST-10 demonstrate strong psychometric properties when used in an Indian psychiatric hospital. Routine use of these brief screens can facilitate detection of substance use disorders among psychiatric patients.

Adult↗
PubMed2000

Psychiatric epidemiology: selected recent advances and future directions.

Reviewed in this article are selected recent advances and future challenges for psychiatric epidemiology. Major advances in descriptive psychiatric epidemiology in recent years include the development of reliable and valid fully structured diagnostic interviews, the implementation of parallel cross-national surveys of the prevalences and correlates of mental disorders, and the initiation of research in clinical epidemiology. Remaining challenges include the refinement of diagnostic categories and criteria, recognition and evaluation of systematic underreporting bias in surveys of mental disorders, creation and use of accurate assessment tools for studying disorders of children, adolescents, the elderly, and people in less developed countries, and setting up systems to carry out small area estimations for needs assessment and programme planning. Advances in analytical and experimental epidemiology have been more modest. A major challenge is for psychiatric epidemiologists to increase the relevance of their analytical research to their colleagues in preventative psychiatry as well as to social policy analysts. Another challenge is to develop interventions aimed at increasing the proportion of people with mental disorders who receive treatment. Despite encouraging advances, much work still needs to be conducted before psychiatric epidemiology can realize its potential to improve the mental health of populations.

Epidemiology↗
PubMed2001

[Specific aspects of rhinomanometry in children with nasal septum deformity in the region of absorbing part of the nasal valve].

Available are original data on rhinomanometry in children with nasal septum distortion in the anterior part. Nasal patency before and after anemisation of the mucosa was measured in health and disease. Pressure in collapse of the nasal valve in children is higher than in adults, while dynamic range of the valve action in growing flow of the inspired air is more noticeable. In distortion of the nasal septum at the level of the absorbing part of the nasal valve anemisation reduces the air flow while the dynamic range is not detected. It is discussed whether early surgical intervention in children under sparing approach to nasal structures is valid.

Child↗
PubMed2003

Attributes of excellence in work-related assessments.

UNLABELLED: In order for clinicians to select and conduct work-related assessments that demonstrate 'best practice', it is necessary to identify assessments that are considered 'excellent'. OBJECTIVES: The aims of this study were to determine (1) the attributes associated with excellence for each of 3 types of work-related assessment (WPAs, FCEJs & FCENJs), and (2) the differences between the attributes associated with each type of work-related assessment. STUDY DESIGN: A questionnaire was sent to all accredited occupational or vocational rehabilitation providers in Australia, targeting occupational therapists and physiotherapists who conducted work-related assessments. The response rate was 25.3%, and 132 questionnaires were analysed. RESULTS: A MANOVA revealed that the perceived importance of 18 attributes was different between the 3 forms of work-related assessment F36, 364=6.54; p<0.001). There was a core of 7 attributes that showed no difference between assessments (accurate, comprehensive, credible, flexible, practical, safe and useful). Two attributes (generalisable and specific) were different for all 3 forms of assessment. A large group of attributes (consistent, measurable, objective, reliable, reproducible, standardised, structured and valid) demonstrated significant differences between WPAs and both forms of FCE. Relevant demonstrated significant differences between FCENJs and both WPAs and FCEJs. Reliability analysis revealed 2 constructs (dependability and utility). CONCLUSIONS: This study demonstrated that there were significant differences between 3 forms of work-related assessments (WPAs, FCEJs & FCENJs) in terms of the attributes considered necessary for excellence for each form of assessment. The attributes were considered to relate to either qualitative or quantitative features of assessment. These features were reflected in the constructs utility, which was comprised of qualitative attributes and associated with broad concepts of validity, and dependability, which was comprised of quantitative attributes and reflected concepts of reliability. There appeared to be a continuum of work-related assessment that ranged from WPAs demonstrating the most qualitative attributes to FCENJs demonstrating the most quantitative features.

Analysis of Variance↗
PubMed1985

[Criterion-oriented measurement in clinical psychology: development of a test on stress management].

Criterion-oriented tests evaluate the performance of the individual in relation to a given criterion which describes abilities and skills (intended competencies). The measuring process decides statistically if the person is "mastering" the criterion or not. The intended competencies should be represented by test items of high content-validity. The structure and application of this method especially to diagnostical issues of clinical psychology and therapeutic control are discussed. Steps are described construing a criterion-oriented test of stress and coping processes related to depressive and fearful behavior. The test is based on a situation-action-model in the theoretical framework of "stress and coping", "self-efficacy", "control" and "learned helplessness". Method and construction of items are shown in order to find some dimensions of coping-behavior-in-situations (appraisals, person-directed and environment-directed actions) and its sequential organisation in stressful episodes.

Adaptation, Psychological↗
PubMed1984

Estimation of individually adapted control parameters for an artificial beta cell.

For optimum long-term glycemic regulation using a miniaturized artificial beta cell it is indispensible to estimate control parameters suited to the individual requirements of each diabetic patient. To solve this problem, a strategy has been developed which is based on engineering optimum-control theory with a model involving glucose and insulin interactions. The model considers physiologically relevant unit processes like endogenous glucose production, insulin-independent glucose uptake from its apparent distribution space, insulin-dependent glucose utilization, glucose-dependent insulin supply, and insulin catabolism. The assumed model structure is validated by results obtained in experimentally diabetic dogs using partition analysis. The individual parameter values of the model are obtained by a digital computer procedure based on a simple test which involves a bolus injection of glucose + insulin when a constant basal insulin dose is being administered in the diabetic in whom normoglycemia was re-established before the test. The method presented is recommended for future use in all cases where an optimized insulin regimen is to be worked out.

Animals↗
PubMed1984

[Noninvasive monitoring with echocardiography. I. Ventricular function following thiopental and positive pressure breathing].

Using continuous M-mode echocardiography for measuring diameters of the left ventricle and calculating variables of left ventricular contractility during induction of anaesthesia the hemodynamic effects of thiopentone and of positive end-expiratory pressure breathing (PEEP) have been noninvasively assessed in 22 patients undergoing minor surgery (series A, n = 4 + 6, thiopentone) or cholecystectomy (series B, n = 12, PEEP). 4 mg X kg-1 i.v. (group I, n = 4) and 2 X 4 mg X kg-1, the second dose injected i.v. 5 min later (group II, n = 6), led in group I to a short lasting and in group II to a prolonged (duration of each experiment 10 min) significant decrease of the ejection fraction (EF), the shortening fraction (FS) and the mean velocity of circumferential fiber shortening (VCF mean). Thus the well known negative inotropic effect of thiopentone has been proven once more this time by noninvasive echocardiography. The influence of PEEP 5 and 10 cm H2O was evaluated in two ways: 1) by finding the incidence and extent of diminishing the "echocardiographic window" due to overexpansion of the lung during PEEP, rendering the sonographic visualization of the cardiac structures less valid, and 2) by assessing potential haemodynamic effects of PEEP. The curves of 3 in 12 cases (25%) have not been able to be evaluated properly because of "window closing"; in the residual 9 patients during PEEP 10 a significant decrease of the above mentioned parameters of contractility in comparison to PEEP 0 has been observed. IPPB without PEEP apparently does not disturb echocardiographic visualization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[An analysis of the quality of life of rehabilitated patients].

The improvement of the survival of cardiac patients may cause an impairment of their quality of life. At present, the study of the quality of life of the patients and its changes, must be considered as one of the aims of the Medicine. This study must be comprised clinical, functional, intellectual, social, and labor aspects, and all the items related to the environment of the patient. The first questionnaires used for the study of quality of life were generic but later on, specific questionnaires for different pathologies were found to be preferential. At present, there are questionnaires for hypertensive, myocardial infarction, angina and heart failure patients, and among them the questionnaire for myocardial infarction patients, structures and validated by the authors which has been used to study the quality of life postinfarction patients who followed a cardiac rehabilitation programme.

Humans↗