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PubMed2006

Evaluating the properties of a stage-specific self-efficacy scale for physical activity using classical test theory, confirmatory factor analysis and item response modeling.

The purpose of this paper was to evaluate the psychometric properties of a stage-specific self-efficacy scale for physical activity with classical test theory (CTT), confirmatory factor analysis (CFA) and item response modeling (IRM). Women who enrolled in the Women On The Move study completed a 20-item stage-specific self-efficacy scale developed for this study [n=226, 51.1% African-American and 48.9% Hispanic women, mean age = 49.2 (+/-7.0) years, mean body mass index = 29.7 (+/-6.4)]. Three analyses were conducted: (i) a CTT item analysis, (ii) a CFA to validate the factor structure and (iii) an IRM analysis. The CTT item analysis and the CFA results showed that the scale had high internal consistency (ranging from 0.76 to 0.93) and a strong factor structure. Results also showed that the scale could be improved by modifying or eliminating some of the existing items without significantly altering the content of the scale. The IRM results also showed that the scale had few items that targeted high self-efficacy and the stage-specific assumption underlying the scale was rejected. In addition, the IRM analyses found that the five-point response format functioned more like a four-point response format. Overall, employing multiple methods to assess the psychometric properties of the stage-specific self-efficacy scale demonstrated the complimentary nature of these methods and it highlighted the strengths and weaknesses of this scale.

Adult↗
PubMed1984

Assessment of type A behaviour by the Bortner scale and ischaemic heart disease. The Belgian-French Pooling Project.

In a French -Belgian collaborative study the incidence of coronary heart disease (CHD) in 2699 middle-aged males was related to the type A behaviour pattern assessed by means of the Bortner scale, which had been validated against the structured interview of Rosenman and Friedman in the Belgian subgroup. The relative risks of the fourth to the first quartile of the Bortner Scale were 1.70, 1.64 and 1.84 for total CHD, hard and soft events, respectively. The relationships of type A behaviour to CHD was independent of age, smoking, systolic blood pressure, serum cholesterol, body build and socio-professional status.

Adult↗
PubMed1986

Evaluation of total anomalous pulmonary venous drainage with cross-sectional colour-flow Doppler echocardiography.

Three patients with total anomalous pulmonary venous drainage (TAPVD) were studied by real-time cross-sectional colour-flow Doppler echocardiography. Serial suprasternal, parasternal and subcostal scans were obtained. In all cases surgical or angiocardiographic confirmation was available. Two patients had supracardiac drainage (to the left vertical vein or to the right superior vena cava) and one patient had infracardiac drainage. An abnormal forward flow in the left innominate vein and vertical vein was visualized in those patients with supracardiac TAPVD. Abnormal venous flow was also imaged in one patient with mixed drainage. In the patient with infradiaphragmatic TAPVD characteristic flow signals were identified in the inferior vena cava (retrograde flow) and in the descending aorta and anomalous pulmonary venous channel (forward flow). In all patients the patterns of pulmonary venous flow allowed us to distinguish TAPVD from contiguous structures and to validate two-dimensional cross-sectional imaging.

Brachiocephalic Veins↗
PubMed2001

Contribution of engineered electrostatic interactions to the stability of cytosolic malate dehydrogenase.

Protein engineering is a promising tool to obtain stable proteins. Comparison between homologous thermophilic and mesophilic enzymes from a given structural family can reveal structural features responsible for the enhanced stability of thermophilic proteins. Structures from pig heart cytosolic and Thermus flavus malate dehydrogenases (cMDH, Tf MDH), two proteins showing a 55% sequence homology, were compared with the aim of increasing cMDH stability using features from the Thermus flavus enzyme. Three potential salt bridges from Tf MDH were selected on the basis of their location in the protein (surface R176-D200, inter-subunit E57-K168 and intrasubunit R149-E275) and implemented on cMDH using site-directed mutagenesis. Mutants containing E275 were not produced in any detectable amount, which shows that the energy penalty of introducing a charge imbalance in a region that was not exposed to solvent was too unfavourable to allow proper folding of the protein. The salt bridge R149-E275, if formed, would not enhance stability enough to overcome this effect. The remaining mutants were expressed and active and no differences from wild-type other than stability were found. Of the mutants assayed, Q57E/L168K led to a stability increase of 0.4 kcal/mol, as determined by either guanidinium chloride denaturalization or thermal inactivation experiments. This results in a 15 degrees C shift in the optimal temperature, thus confirming that the inter-subunit salt bridge initially present in the T.flavus enzyme was formed in the cMDH structure and that the extra energy obtained is transformed into an increase in protein stability. These results indicate that the use of structural features of thermophilic enzymes, revealed by a detailed comparison of three-dimensional structures, is a valid strategy to improve the stability of mesophilic malate dehydrogenases.

Catalysis↗
PubMed2004

Use of standardized patients to enhance a psychiatry clerkship.

Changes in psychiatric health care delivery driven by such major shifts as deinstitutionalization, community-based care, and managed care have greatly altered the educational milieu for third-year psychiatry clerkships. Students may be assigned exclusively to alcohol and substance abuse treatment units, consultation-liaison services, or outpatient clinics, and may not have as broad an exposure as is desirable to patients with a variety of psychiatric illnesses. The authors describe a pilot course they developed in 2001, Clinical Psychiatric Assessment and Diagnosis, for third-year medical students at the Uniformed Services University of the Health Sciences medical school. The course uses standardized patients (SPs) to help students gain broader clinical experience. In psychiatry, a growing body of literature supports the acceptability, reliability, and validity of objective structured clinical examination assessment using SPs for medical students. Only a few articles report the use of SPs to primarily teach psychiatry instead of evaluating student proficiency in clinical psychiatry. Since this course was developed, the National Board of Medical Examiners announced that all medical students will be required to pass a clinical skills test in order to practice medicine, beginning with the class of 2005. The examination will use SPs modeling different clinical scenarios. In light of this change, many medical schools may have to reevaluate and possibly revamp their curriculums to insure sufficient acquisition of clinical skills in different specialties. The use of SPs in psychiatry could provide an effective, primary clinical teaching experience to address this new requirement as well.

Clinical Clerkship↗
PubMed2006

Assessing the underlying structure of the United States Medical Licensing Examination Step 2 test of clinical skills using confirmatory factor analysis.

BACKGROUND: The purpose of the present study was to assess the fit of three factor analytic (FA) models with a representative set of United States Medical Licensing Examination (USMLE) Step 2 Clinical Skills (CS) cases and examinees based on substantive considerations. METHOD: Checklist, patient note, communication and interpersonal skills, as well as spoken English proficiency data were collected from 387 examinees on a set of four USMLE Step 2 CS cases. The fit of skills-based, case-based, and hybrid models was assessed. RESULTS: Findings show that a skills-based model best accounted for performance on the set of four CS cases. CONCLUSION: Results of this study provide evidence to support the structural aspect of validity. The proficiency set used by examinees when performing on the Step 2 CS cases is consistent with the scoring rubric employed and the blueprint used in form assembly. These findings will be discussed in light of past research in this area.

Clinical Competence↗
PubMed1995

Assessing the efficacy of treatments for panic disorder and agoraphobia. II. The Panic and Agoraphobia Scale.

Despite the plethora of rating scales for anxiety disorders and agoraphobia, a qualified scale for assessing the severity of panic disorder and agoraphobia (PDA) is still lacking. The new Panic and Agoraphobia Scale (P&A) is presented in this paper. It was developed to assess the degree of severity of these disorders after a diagnosis has been made according to the criteria of the DSM-III-R/IV or the ICD-10. The P&A was specially developed for use in clinical drug trials. Factors which impair the quality of life in panic disorder and agoraphobia patients (panic attacks, phobic avoidance, anticipatory anxiety, impairment in social relationships and work, assumption of somatic disease) were considered in the development of this scale so that the efficacy of a certain drug therapy on each of these factors can be assessed separately. Both an observer rating and a self-rating with matching items are available. The observer rating only takes about 10 minutes to complete. Translation into many European languages is planned so that it can be used in multicentre trials. Satisfactory results of item analysis, inter-rater reliability, objectivity, external validity and factor structure are presented. The P&A should be a useful tool for assessing the severity of PDA and may solve some of the methodological problems that have arisen in former PDA studies.

Adult↗
PubMed2006

Somatization an independent psychosocial risk factor for irritable bowel syndrome but not dyspepsia: a population-based study.

BACKGROUND: A psychosocial conceptualization for irritable bowel syndrome and unexplained dyspepsia has been proposed, but remains untested. We conducted a comprehensive population-based study to determine what psychiatric and psychosocial factors, if any, are important in irritable bowel syndrome and dyspepsia. METHODS: Two hundred and seven participants identified from two previous Australian population surveys who also met Rome I criteria for irritable bowel syndrome (n=156) or unexplained dyspepsia (n=51) were included in the study. Consulters (n=103) were those who had had visited their general practitioner for gastrointestinal symptoms at least once in the prior 12 months. Nonconsulters had not sought medical care for gastrointestinal symptoms in the past year. Controls (n=100) did not report having any abdominal pain in a previous population survey. Psychosocial variables were assessed using structured interviews and validated self-report measures. RESULTS: Psychiatric diagnoses, neuroticism, more highly threatening life event stress, an external locus of control and ineffectual coping styles were significantly associated with having a diagnosis of irritable bowel syndrome and/or dyspepsia. Only somatization (odds ratio=5.28, 95% confidence interval 1.57-17.68), however, was independently associated with irritable bowel syndrome. Psychosocial factors did not discriminate between consulters and nonconsulters. CONCLUSIONS: Somatization is likely play a key role in explaining irritable bowel syndrome but not dyspepsia.

Adaptation, Psychological↗
PubMed1990

Location of epitopes on the major core protein p24 of human immunodeficiency virus.

Antibody-binding sites were mapped on all overlapping nonapeptides of the major core protein p24 of human immunodeficiency virus type 1 (HIV-1) using murine monoclonal antibodies (MAbs) and sheep and rabbit polyclonal antibodies raised against HIV-1/H9 (strain IIIB) viral lysate and antibodies obtained from humans infected with HIV-1. The binding sites were mapped to various distinct regions of this protein. After superimposition of the antibody-binding sites on a proposed model of p24 of HIV-1, these sites appeared to be located on the surface of the protein on loops, turns and coils of p24 but, unexpectedly, not on the major part of the predicted 'puff'. Little reaction was found with the inaccessible anti-parallel beta-barrel. These results are the first experimental evidence for the validity of the structure proposed for p24 of HIV-1.

Amino Acid Sequence↗
PubMed2025

Genome-wide diversity of chromosomal inversions and their disease relationships.

Chromosomal inversions shape evolution and are implicated in human disease, yet their effects on genomic variation and health outcomes remain poorly understood. We analyze genome-wide human inversion polymorphisms, contrasting single-event and recurrent loci. Inversion recurrence is validated using structured-coalescent simulations. We show that single-event inversions evolve in near-complete isolation: inverted haplotypes show ~16-fold lower diversity and strong differentiation from direct haplotypes (median FST = 0.33). By contrast, recurrent inversions maintain gene flow, resulting in similar diversity across orientations and ~4-fold lower differentiation. We further find marked differences in coding sequence conservation between single-event and recurrent inversions. Using the NIH All of Us biobank, we impute inversions and identify four inversions with significant disease associations. Notably, the 17q21 inversion is associated with reduced risk of cognitive decline (OR=0.919) and breast cancer (OR=0.910) but with increased obesity risk (OR=1.097), consistent with pleiotropic selection. These findings establish inversions as major drivers of human genetic diversity and disease, with evolutionary outcomes critically dependent on recurrence.

Evolution↗
PubMed2000

Docking structures of domains into maps from cryo-electron microscopy using local correlation.

Accurate maps of large macromolecular complexes can be calculated from cryo-electron micrographs of non-crystalline specimens to resolutions of about 10 A. A method to dock the atomic structures of domains solved by X-ray crystallography or nuclear magnetic resonance into cryo-EM maps is presented. Domains can be docked independently into large complexes without prior definition of the boundaries. No special symmetry is assumed and the procedure is suitable for general application to almost any system where a cryo-EM map (at 15 A resolution or better) of a complex has been obtained and the atomic structures of the components are available. This is achieved through use of a real-space density-matching procedure based on local correlation. A complete asymmetric unit search correlating a density object derived from the atomic coordinates and the density of the EM map is performed. The correlation coefficient is calculated locally in real space using only values of the search object and corresponding samples extracted from the EM map which are under the 'footprint' of the positioned search object. The procedure has been demonstrated by docking the domains of GroEL from the crystal structure into a cryo-EM map Fourier filtered to 12 or 15 A resolution. The correct positions were found without applying any additional constraints. A model of the oligomer built from the docked domains compared favourably with the known crystal structure, confirming the validity of the approach. The procedure is designed to facilitate the incorporation of additional constraints on the docking solutions, which could help to dock using lower resolution maps.

Algorithms↗
PubMed1994

Acuracy of refined protein structures. II. Comparison of four independently refined models of human interleukin 1beta.

To assess the accuracy of refined structures, a comparison was made using independently determined structures of the same protein in the same crystal form. The models were re-refined against a common data set to minimize the effects of different data and different refinement protocols. The process did not converge to a single model. Rather the structures differed from each other by 0.84 A which was roughly three times that predicted by a Luzzati analysis [Luzzati (1952). Acta Cryst. 5, 802-810]. The individual structures are equally valid and at least partially independent as evidenced by a reduction of the R factor by 0.013 when a simple linear combination is used. Only 29 solvent molecules were common to all four models.

Journal Article↗
PubMed2006

Modeling emotional content of music using system identification.

Research was conducted to develop a methodology to model the emotional content of music as a function of time and musical features. Emotion is quantified using the dimensions valence and arousal, and system-identification techniques are used to create the models. Results demonstrate that system identification provides a means to generalize the emotional content for a genre of music. The average R2 statistic of a valid linear model structure is 21.9% for valence and 78.4% for arousal. The proposed method of constructing models of emotional content generalizes previous time-series models and removes ambiguity from classifiers of emotion.

Artificial Intelligence↗
PubMed2006

Concurrent validity of the Alcohol Use Disorders Identification Test (AUDIT) and AUDIT zones in defining levels of severity among out-patients with alcohol dependence in the COMBINE study.

AIMS: To examine among alcohol-dependent out-patient clients the concurrent validity of the Alcohol Use Disorders Identification Test (AUDIT) total score and 'zones' suggested by the World Health Organization for defining levels of severity of alcohol use problems. DESIGN: Participants were classified into AUDIT zones (AUDIT total score = 8-15, 16-19, 20-40) and compared on measures of demographics, treatment goals, alcohol consumption, alcohol-related consequences, severity of dependence, physiological dependence, tolerance, withdrawal and biomarkers of alcohol use. SETTING: Eleven out-patient academic clinical research centers across the United States. Participants Alcohol dependent individuals (n = 1335) entering out-patient treatment in the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) study. MEASUREMENTS: The AUDIT was administered as part of an initial screening. Baseline measures used for concurrent validation included the Structured Clinical Interview for Diagnostic and Statistical Manual, 4th edition (DSM-IV) Disorders, the Alcohol Dependence Scale, the Drinker Inventory of Consequences, the Obsessive-Compulsive Drinking Scale, the University of Rhode Island Change Assessment, the Thoughts about Abstinence Scale, the Form-90, %carbohydrate-deficient transferrin and gamma-glutamyl transferase. Findings Indicators of severity of dependence and alcohol-related problems increased linearly with total score and differed significantly across AUDIT zones. The highest zone, with scores of 20 and above, was markedly different with respect to severity from the other two zones and members of this group endorsed an abstinence goal more strongly. CONCLUSIONS: The AUDIT total score is a brief measure that appears to provide an index of severity of dependence in a sample of alcohol-dependent individuals seeking out-patient treatment, extending its potential utility beyond its more traditional role as a screening instrument in general populations.

Alcohol-Related Disorders↗
PubMed2005

Barriers to the effective management of bipolar disorder: a survey of psychiatrists based in the UK and USA.

OBJECTIVE: To identify and prioritize barriers, challenges, and unmet needs in the management of patients with bipolar disorder, as perceived by their psychiatrists. METHODS: A total of 500 US- or UK-based psychiatrists were surveyed by telephone using a validated, semi-structured questionnaire. Both preidentified and participant-elicited barriers, challenges and unmet needs were ranked on a 0-6 point scale in four phases of management: I, entry into care; II, the manic/hypomanic phase; III, the depressive phase; and IV, the long-term/maintenance phase. RESULTS: Education and support for patients and families as well as earlier referral to specialist care were the highest ranked needs at entry into care. During treatment of acute episodes and long-term management the highest ranked needs were for treatments with improved effectiveness and patient adherence, in addition to improved long-term safety in the maintenance phase. Patients with comorbid alcohol and/or substance use disorders, followed by patients with a rapid-cycling disease course, were rated as having the highest level of unmet need. Similarities were predominantly seen between the overall pattern of responses from UK- and US-based psychiatrists. CONCLUSIONS: The highest priority items across the spectrum of treatment related to the need for clinically effective therapeutic agents with broad efficacy and favorable tolerability. At the time of initial diagnosis, patient education, family support, and earlier referral to specialist care were the highest priority needs.

Bipolar Disorder↗
PubMed1978

A 1H nuclear-magnetic-resonance study of the solution conformation of the isoinhibitor K from Helix pomatia.

The isoinhibitor K from Helix pomatia was investigated by high-resolution 1H nuclear magnetic resonance at 360 MHZ. Detailed studies of the labile protons and the resonances of the aromatic residues indicated extensive homologies between the spatial structures of the snail inhibitor, the basic pancreatic trypsin inhibitor (Kunitz) from bovine tissue and the cos colostrum trypsin inhibitor. Comparison of these three homologous inhibitors indicated that the overall flexibility of the globular protein conformation is reduced and its stability with respect to thermal denaturation raised when the content of amino acids with charged side chains is increased. It is suggested that this relation between amino acid composition and stability of the globular solution structure might be valid also for other classes of homologous proteins.

Amino Acid Sequence↗
PubMed2006

Countertransference to psychiatric patients in a clinical setting: development of the Feeling Checklist-Japanese version.

Countertransference is an important dimension of the therapeutic alliance between care providers and patients. The Feeling Checklist (FC) is a self-report questionnaire for the assessment of countertransference by hospital staff toward patients. The FC was translated from English into Japanese and its factor structure, reliability, and validity in the Japanese version (FC-J) were examined. A total of 281 Japanese psychiatric nurses were tested with the FC-J. All nurses were primarily involved in provision of psychiatric care. Principal-component factor analysis with varimax rotation was performed to identify the potential components of the FC-J. In a factor analysis of the FC-J, seven factors were extracted. The five subscales that were determined and labeled included Reject, Distance, Helpfulness, Closeness, and Involvement, which collectively accounted for 56.0% of the variance. Cronbach's alpha, a measure of internal consistency, for individual subscales was 0.833 for Reject, 0.763 for Distance, 0.768 for Helpfulness, 0.617 for Closeness, and 0.663 for Involvement. Notably, there was a significant correlation between the FC-J and the Nurse Attitude Scale (P < 0.0001). Moreover, one-way anova was performed with each FC-J subscale to examine differences among psychiatric diagnoses in the study sample. A significant difference was found for Involvement (P < 0.001), with the total score on Involvement being the highest in the personality disorder group. These results are considered to verify the reliability and validity of the FC-J as a scale to measure countertransference among Japanese care providers. The use of this scale allows individual care providers to recognize and be cognizant of their own countertransference objectively and thereby contributes to improve the relationship between patients and care providers.

Adult↗
PubMed1990

Personality organization defined by DMT and the Structural Interview.

The psychoanalytic concept of Personality Organization (PO) may be operationalized by means of a Structural Interview as well as by means of psychological tests. The present study utilized the Structural Interview and a projective test called the Defence Mechanism Test (DMT) to operationalize the PO concept on a sample of 50 psychiatric inpatients. The reliability of the PO judgements were found to be acceptable for both the Structural Interview and the DMT. The validity, which was estimated as the correlation between the two methods, was also found to be substantial. The conclusion is that the concept of PO may be reliably operationalized for psychiatric patients and seems to have concurrent validity. Both the DMT and the Structural Interview may be used for differential diagnosis of PO.

Adult↗