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PubMed2004

Repeated validation of parental self-reported smoking during pregnancy and infancy: a prospective cohort study of infants at high risk for allergy development.

Exposure to environmental tobacco smoke (ETS) during fetal life and infancy is closely related to the smoking habits of the parents. Estimates of exposure to ETS require valid and detailed information on changes in cigarette smoking over time. The objective was to test the validity of self-reported smoking among parents during pregnancy and early childhood in a cohort of children at high risk for allergy development by measurement of exhaled carbon monoxide (CO). The cohort comprised 117 families enrolled from the general population of pregnant women at admission to antenatal care. Data on parental tobacco smoking were obtained by interview and exhaled CO was measured (Micro-Smokerlyzer(R)) in parents twice during pregnancy and when the child was 6 and 18 months old. The median (range) exhaled CO levels were 3 (0-10) parts per million (ppm) for non-smokers and 15 (1-39) ppm for smokers (P < 0.0005). A receiver operating characteristic (ROC) analysis was performed at each examination. The areas under the ROC curve were high for both mothers (between 0.88 and 0.99) and fathers (between 0.87 and 0.89), indicating exhaled CO as a good diagnostic tool for determining smoking status. Comparing the ROC areas obtained for mothers from late pregnancy and during infancy with the area from early pregnancy showed no statistical differences (P = 0.21, 0.43 and 0.44 respectively) and the same was true for fathers during infancy (P = 0.81). The level of 8 ppm was used as the cut-off between smokers and non-smokers, based on data from a pilot study. Using CO as a diagnostic tool for smoker status showed very high specificity (between 97 and 100%), indicating that very few persons claiming to be non-smokers had CO levels higher than 8 ppm. In conclusion, the validity of interview-obtained self-reported smoking among parents during pregnancy and early childhood was high. Repeated interviews and CO measurements in a prospective study design did not change the validity, indicating a low risk of information bias. A structured interview combined with measurement of exhaled CO is a valid and reliable method for estimating ETS exposure to the fetus and young infant.

Breath Tests↗
PubMed1993

Surgery resident selection and evaluation. A critical incident study.

This article reports a study of the process of selecting and evaluating general surgery residents. In personnel psychology terms, a job analysis of general surgery was conducted using the Critical Incident Technique (CIT). The researchers collected 235 critical incidents through structured interviews with 10 general surgery faculty members and four senior residents. The researchers then directed the surgeons in a two-step process of sorting the incidents into categories and naming the categories. The final essential categories of behavior to define surgical competence were derived through discussion among the surgeons until a consensus was formed. Those categories are knowledge/self-education, clinical performance, diagnostic skills, surgical skills, communication skills, reliability, integrity, compassion, organization skills, motivation, emotional control, and personal appearance. These categories were then used to develop an interview evaluation form for selection purposes and a performance evaluation form to be used throughout residency training. Thus a continuum of evaluation was established. The categories and critical incidents were also used to structure the interview process, which has demonstrated increased interview validity and reliability in many other studies. A handbook for structuring the interviews faculty members conduct with applicants was written, and an interview training session was held with the faculty. The process of implementation of the structured selection interviews is being documented currently through qualitative research.

Clinical Competence↗
PubMed1999

Structured tree outflow condition for blood flow in larger systemic arteries.

A central problem in modeling blood flow and pressure in the larger systemic arteries is determining a physiologically based boundary condition so that the arterial tree can be truncated after a few generations. We have used a structured tree attached to the terminal branches of the truncated arterial tree in which the root impedance is estimated using a semianalytical approach based on a linearization of the viscous axisymmetric Navier-Stokes equations. This provides a dynamic boundary condition that maintains the phase lag between blood flow and pressure as well as the high-frequency oscillations present in the impedance spectra. Furthermore, it accommodates the wave propagation effects for the entire systemic arterial tree. The result is a model that is physiologically adequate as well as computationally feasible. For validation, we have compared the structured tree model with a pure resistance and a windkessel model as well as with measured data.

Arteries↗
PubMed2001

Design, synthesis, and evaluation of novel A2A adenosine receptor agonists.

We have been interested in the design, synthesis, and evaluation of novel adenosine A2A agonists. Through the use of comparative molecular field analysis (CoMFA) we have generated a training model that includes 78 structurally diverse A2A agonists and correlated their affinity for isolated rat brain receptors with differences in their structural and electrostatic properties. We validated this model by predicting the activity of a test set that included 24 additional A2A agonists. Our CoMFA model, which incorporates the physiochemical property of dipole and selects against A1 receptor activity, generated a correlated final model (r2 = 0.891) that provides for enhanced A2A selectivity and predictability. Synthesis, pharmacological evaluation, and modeling of four novel ligands further validate the utility and predictive power (r2 = 0.626) of the CoMFA model.

Alkynes↗
PubMed2005

Medical student selection: choice of a semi-structured panel interview or an unstructured one-on-one interview.

Reliability has been shown to be higher in structured medical admissions interviews as compared to unstructured interviews. This study reports the comparison of a proposed semi-structured panel interview with a current individual unstructured medical admissions interview. Inter-rater reliability coefficients were calculated, and correlations were estimated between panel, individual and academic scores. Admission status in 2003 was related to these scores by means of logistic regression. Both individual and panel interviews were significantly correlated with admissions status. The inter rater reliability coefficient (from individual interviews) was 0.12 whereas the interpanel reliability coefficient was 0.52. Panel interview: good across panel and within panel consistency of scoring. No effect of who asked the questions, question order, or interview duration on scoring. No correlation between panel interview scores and academic variables (MCAT, GPA). We found good inter-panel reliability, a high consistency within and between interview panels, and uniformly positive questionnaire responses. The panel interview measures something different from academic variables. These data, in conjunction with a strong sense from the medical and psychological literature supporting the reliability and validity of a semi-structured panel interview, support our decision to replace our individual interview with the panel interview.

Adult↗
PubMed2005

Validation of speed of sound for the assessment of cortical bone maturity.

Bone changes its structural and physical properties during maturation. In order to validate ultrasound measurements with regard to their usefulness in assessing cortical bone maturation, speed of sound (SOS) data were compared with mechanical properties (elastic modulus, bending strength, and cortical surface hardness), density and water content. Thirty pig mandibles were selected from three different age groups. Rectangular specimens of the buccal cortical bone of the body of the mandible were prepared. SOS was measured with pulsed ultrasound at a frequency of 2 MHz in all three dimensions, bone mineral density (BMD) by quantitative computed tomography, breaking strength and apparent elastic modulus in a three-point bending test to failure, water content using the lyophilization technique, and micro-indentation hardness using a modified Vickers' technique. While SOS in all three directions, BMD, surface hardness, and bending strength increased significantly (P < 0.001), bone tissue water content decreased significantly (P < 0.001) with age. Changes in the elastic modulus were not significant. Changes in SOS in the antero-posterior and apico-occlusal directions can be partly explained by BMD. In a bucco-lingual direction the increase is inadequately explained by the physical parameters investigated, and has possibly to be attributed to structural differences. Maturation of the mandible implies changes in its architectural organization, in material composition, and in the mechanical properties of cortical bone. In vitro SOS measurements reflect different structural and physical properties that are all age dependent. It thus seems feasible that age-related changes in bone maturation could be monitored by SOS measurements.

Age Factors↗
PubMed2004

Validation of the Brief Pain Inventory for chronic nonmalignant pain.

UNLABELLED: The Brief Pain Inventory (BPI; Cleeland and associates) has been used primarily to assess patients with cancer-related pain. Although it has been validated in many languages and is widely used, there has not yet been research published to validate its use for patients with chronic nonmalignant pain as the primary presenting problem. This study was designed to fill this gap by examining the psychometric properties of the BPI in 440 patients with chronic intractable pain referred to a chronic pain clinic at a metropolitan tertiary-care teaching hospital. Results indicated acceptable internal consistency (Cronbach alpha coefficients were.85 for the intensity items and.88 for the interference items). A factor analysis resulted in 2 distinct and independent factors, supporting the validity of the 2-factor structure of the BPI. Zero-order correlations indicated that the association with a measure of disability (the Roland-Morris Disability Questionnaire [RMDQ]) was significantly higher for BPI interference (r = 0.57) than for BPI intensity (r = 0.40, t = 5.71, P <.01) and that the correlation with BPI interference was not more than 0.80, supporting the conclusion that these scales assess related, but also distinct, dimensions. Finally, the finding that both BPI scales showed statistically significant improvement with treatment confirms the responsivity of BPI in detecting and reflecting improvement in pain over time. PERSPECTIVE: This paper validated the psychometric properties of a pain Assessment instrument (The Brief Pain Inventory) originally developed to assess cancer pain and extended its use for the chronic nonmalignant pain population. This provides an important and widely used diagnostic tool for the clinician treating chronic pain.

Chronic Disease↗
PubMed2004

Developing a rating scale for projected stories.

The Six-part Story Method (6PSM) is a projective tool in wide use by dramatherapists in the UK, USA and Israel (Lahad & Ayalon, 1993). In contrast to projective tests used by psychotherapists and psychologists, the 6PSM has never been the subject of any validation or reliability studies. This study reports on the identification of scale items to describe the manifest content of six-part stories. In all, 26 statements with acceptable inter-rater reliability have been identified. These statements were used to rate stories produced by clinicians (N = 24) mainstream community mental health patients (N = 21) and patients with a borderline personality disorder (N = 19). Some features that were expected to be indicators of an author with a BPD diagnosis proved to be as common in stories from other authors. However, a scale of eight items was identified that differentiated well between authors with a BPD diagnosis and others, with adequate test-retest and inter-rater reliability. Concurrent validity was tested against the Structured Clinical Interview for DSM-IV Axis II (SCID-II), the Clinical Outcomes in Routine Evaluation Outcome Measure (CORE-OM) and the Inventory of Interpersonal Problems--Short Form (IIP-32).

Humans↗
PubMed2005

Development of indicators to assess the quality of nursing care in Thailand.

In Thailand, quality of nursing care has been defined. The next step is to determine how to measure quality. Given the limited resources to provide health care and the demands to justify the use of registered nurses, there is an urgent need to demonstrate how professional nursing care makes a difference to outcomes of care. The purpose of this study was to further refine nursing indicators of quality by developing operational definitions, validating them and then determining their applicability in a variety of clinical settings. The process included three phases. The first phase used focus groups to identify and define indicators of quality nursing care and the second phase included testing these indicators in four settings to determine if data could be collected. Manuals were developed that defined the quality indicators and the scoring system to be used in the assessment. In the third phase, the findings were presented to a group of experts and minor changes were made to the indicators. Then, the indicators were categorized into three groups: structure, process, and outcome. The validated outcomes and manual for their assessment and monitoring were sent to all hospitals in Thailand. The study relied upon the findings from the four different hospitals. If the indicators were implemented in a wider variety of settings, other differences might have emerged. There is also a possibility that 'best practice' might not be reflective of the scientific basis of nursing practice. The findings generally support the initial work carried out in the USA. There is a need to continue to study how these indicators can improve patient outcomes.

Clinical Nursing Research↗
PubMed1981

Diagnostic interview for borderline patients. A replication study.

The borderline diagnosis is widely used despite a lack of systematic research on its reliability and validity. The recent development of a structured interview incorporating diagnostic criteria for borderline disorders in a replicable format represents a necessary, but not sufficient, methodological step in testing the validity of the borderline concept. To our knowledge, this is the first replication of Gunderson's Diagnostic Interview for Borderlines in a clinical setting and population quite different from the original. Clinically defined borderline patients were compared with control groups of schizophrenic and nondelusional unipolar depressed patients. Of 29 scored statements on the diagnostic interview, borderlines differed significantly from schizophrenics on 19, from depressives on 16, and from both on 19. Stepwise discriminant-function analyses of borderline vs each comparison group gave substantial support to the reliability of the interview and the diagnostic criteria.

Adult↗
PubMed2006

Error distribution derived NOE distance restraints.

Errors and imprecisions in distance restraints derived from NOESY peak volumes are usually accounted for by generous lower and upper bounds on the distances. In this paper, we propose a new form of distance restraints, replacing the subjective bounds by a potential function obtained from the error distribution of the distances. We derived the shape of the potential from molecular dynamics calculations and by comparison of NMR data with X-ray crystal structures. We used complete cross-validation to derive the optimal weight for the data in the calculation. In a model system with synthetic restraints, the accuracy of the structures improved significantly compared to calculations with the usual form of restraints. For experimental data sets, the structures systematically approach the X-ray crystal structures of the same protein. Also standard quality indicators improve compared to standard calculations. The results did not depend critically on the exact shape of the potential. The new approach is less subjective and uses fewer assumptions in the interpretation of NOESY peak volumes as distance restraints than the usual approach. Figures of merit for the structures, such as the RMS difference from the average structure or the RMS difference from the data, are therefore less biased and more meaningful measures of structure quality than with the usual form of restraints.

Algorithms↗
PubMed2000

Estimating local backbone structural deviation in homology models.

After the atomic coordinates themselves, the most important data in a homology model are the spatial reliability estimates associated with each of the atoms (atom annotation). Recent blind homology modeling predictions have demonstrated that principally correct sequence-structure alignments are achievable to sequence identities as low as 25% [Martin, A.C., MacArthur, M.W., Thornton, J.M., 1997. Assessment of comparative modeling in CASP2. Proteins Suppl(1), 14-28]. The locations and extent of spatial deviations in the backbone between correctly aligned homologous protein structures remained very poorly estimated however, and these errors were the cause of errant loop predictions [Abagyan, R., Batalov, S., Cardozo, T., Totrov, M., Webber, J., Zhou, Y., 1997. Homology modeling with internal coordinate mechanics: deformation zone mapping and improvements of models via conformational search. Proteins Suppl(1), 29-37]. In order to derive accurate measures for local backbone deviations, we made a systematic study of static local backbone deviations between homologous pairs of protein structures. We found that 'through space' proximity to gaps and chain termini, local three-dimensional 'density', three-dimensional environment conservation, and B-factor of the template contribute to local deviations in the backbone in addition to local sequence identity. Based on these finding, we have identified the meaningful ranges of values within which each of these parameters correlates with static local backbone deviation and produced a combined scoring function to greatly improve the estimation of local backbone deviations. The optimized function has more than twice the accuracy of local sequence identity or B-factor alone and was validated in a recent blind structure prediction experiment. This method may be used to evaluate the utility of a preliminary homology model for a particular biological investigation (e.g. drug design) or to provide an improved starting point for molecular mechanics loop prediction methods.

Computer Simulation↗
PubMed2000

Glenohumeral kinematics and capsulo-ligamentous strain resulting from laxity exams.

OBJECTIVE: Identification and quantification of strain in shoulder capsular-ligamentous structures during clinical exams and validation of this testing on cadavers. METHODS: Mercury strain gauges were sutured in seven locations on shoulders from cadavers. An electromagnetic tracker quantified humeral head translations during laxity exams. Strain and humeral position were acquired during performance of Sulcus, Feagin, Apprehension, Load and Shift, Drawer, and Hawkins tests. RESULTS: Anterior humeral head translation in neutral position was primarily constrained by the coracohumeral ligament. With the arm abducted, anterior middle and inferior ligaments also became active. External rotation and abduction activated inferior and middle capsules. Posterior capsule constrained motion for posterior tests in neutral and abduction. Superior and inferior capsular ligaments were active during inferior tests in neutral position. With abduction, inferior ligaments provided primary translation constraint. CONCLUSION: Study of kinematics and strain evaluation on cadavers can yield useful information on mechanisms of glenohumeral instability. Relevance This study clarifies the contribution of specific structures of the shoulder to strain in the joint capsule. It also identifies which structures are challenged by provocative laxity exams commonly used by orthopaedic physicians.

Analysis of Variance↗
PubMed1994

A strategy for the mapping of N-glycans by high-performance capillary electrophoresis.

We have evaluated high-performance capillary electrophoresis (HPCE) with respect to its suitability for use in establishing a carbohydrate-mapping database that would enable a carbohydrate structural analysis by mere comparison of migration times. The suitability of HPCE for carbohydrate structural assignments was ascertained by validation experiments. The migration times of distinct N-glycans, prepared and measured on different days, were shown to be highly reproducible, with a coefficient of variation of usually less than 0.20%, requiring only femtomoles of N-glycan per injection for reliable measurements. By including mesityl oxide and sialic acid as internal standards and a triple-correction method, HPCE fulfills the analytical requirements with respect to accuracy, precision, reproducibility, and sensitivity. The N-glycan-mapping database was established using a newly developed and optimized buffer system containing 1,5-diaminopentane as an organic modifier. Approximately 80 different sialylated N-glycans of known structure, which have thus far been measured and characterized, have been entered into our Lotus 1-2-3 mapping database. The database for structural determinations was tested using the N-linked carbohydrates released from recombinant human urinary erythropoietin (baby hamster kidney) by PNGase F treatment and from bovine serum fetuin and alpha 1-acid glycoprotein by automated and manual (large-scale) hydrazinolysis, respectively. The efficiency of the database and of the triple-correction method was further confirmed by HPCE measurements performed in a different laboratory and by a different analyst who used the HPCE system of a different manufacturer.

Electrophoresis↗
PubMed1992

A strategy for the mapping of N-glycans by high-pH anion-exchange chromatography with pulsed amperometric detection.

We have evaluated the high-pH anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD) with respect to its suitability to establish a carbohydrate mapping database that would enable carbohydrate structural analysis by mere comparison of retention times. The suitability of HPAE-PAD for carbohydrate structural analysis was ascertained by validation experiments. The retention times of distinct N-glycans, prepared and measured on different days, were shown to be highly reproducible, with a coefficient of variation (CV) of less than 0.5%, requiring less than 100 pmol of N-glycan per injection for reliable measurements. Including appropriate internal chromatographic standards, such as (Neu5Ac)1, (Neu5Ac)2, (Neu5Ac)3, and Neu5Gc, the HPAE-PAD method fulfills the analytical requirements with respect to accuracy, precision, reproducibility, and sensitivity. The N-glycan mapping database was established, using two optimized linear gradients "S" and "A" for sialylated and asialo N-glycans, respectively. Approximately 100 different N-glycans of known structure, which have thus far been measured and characterized, have entered our Lotus 1-2-3 mapping database. The efficiency of the database for structural determinations was tested, using the N-linked carbohydrates isolated from rhuEPO, expressed in BHK cells. Nine different sialylated N-glycans of rhuEPO (BHK) could be assigned with a deviation of less than +/- 0.5%, using gradient S, and six of the eight asialo N-glycans of rhuEPO (BHK) detected with gradient A could be assigned with an accuracy of less than +/- 1%, three of them even with an accuracy of less than 0.1%, providing the reliability of the established HPAE-PAD mapping database.

Carbohydrate Conformation↗
PubMed1996

Structural and stereoelectronic requirements for the inhibition of mammalian 2,3-oxidosqualene cyclase by substituted isoquinoline derivatives.

2,3-Oxidosqualene lanosterol-cyclase (OSC; EC 5.4.99.7) is an attractive target for the design of compounds that block hepatic cholesterol biosynthesis. (4a alpha, 5 alpha, 6 beta, 8a beta)-Decahydro-5,8a-dimethyl-2-(1,5,9-trimethyldecyl)-6- isoquinolinol (1) and simplified analogs have been devised to inhibit this enzyme by mimicking the postulated pro-C-8 high-energy intermediary carbocation occurring during the cyclization-rearrangement pathway. In order to gain an understanding into the mechanism by which these types of molecules inhibit OSC, we have synthesized a series of substituted isoquinoline derivatives 3 and investigated the structural and stereoelectronic requirements, and their stringency, that make 3 potential high-energy intermediate analogs of OSC. Determination of the IC50 values of the different compounds with rat liver microsomal cyclase, allowed the study of the relative importance of (i) the nature and the stereochemistry of the nitrogen side chain, (ii) the presence of methyl groups at C-5 and C-8a (ring junction), (iii) the presence and stereochemistry of the C-6 hydroxyl group, (iv) the nature of the ring junction, and (v) the absolute configuration of the bicyclic system. The resulting structure-activity relationships seem to validate the mechanism of action of these inhibitors as analogs of a pro-C-8 high-energy intermediate and delineate the minimal requirements for the design of efficient isoquinoline-based, or simplified, OSC inhibitors.

Animals↗
PubMed1997

The Changes in Sexual Functioning Questionnaire (CSFQ): development, reliability, and validity.

The Changes in Sexual Functioning Questionnaire (CSFQ), a structured interview/questionnaire designed to measure illness- and medication-related changes in sexual functioning, is presented with evidence of its validity and reliability. Medical students (n = 122) and psychiatry residents (n = 33) completed the CSFQ on two separate occasions. Residents also completed the Derogatis Interview for Sexual Functioning-Self-Report (DISF-SR), a reliable, validated measure used in research on sexual functioning in patient populations. Concurrent validity was established between the CSFQ and the DISF-SR and test-retest reliability was high. The CSFQ is a reliable and valid measure of sexual functioning, useful in both clinical and research settings.

Adult↗
PubMedDate not supplied

Structure-based pharmacophore design and virtual screening for novel angiotensin converting enzyme 2 inhibitors.

The metallopeptidase Angiotensin Converting Enzyme (ACE) is an important drug target for the treatment of hypertension, heart, kidney, and lung disease. Recently, a close and unique human ACE homologue termed ACE2 has been identified and found to be an interesting new cardiorenal disease target. With the recently resolved inhibitor-bound ACE2 crystal structure available, we have attempted a structure-based approach to identify novel potent and selective inhibitors. Computational approaches focus on pharmacophore-based virtual screening of large compound databases. Selectivity was ensured by initial screening for ACE inhibitors within an internal database and the Derwent World Drug Index, which could be reduced to zero false positives and 0.1% hit rate, respectively. An average hit reduction of 0.44% was achieved with a five feature hypothesis, searching approximately 3.8 million compounds from various commercial databases. Seventeen compounds were selected based on high fit values as well as diverse structure and subjected to experimental validation in a bioassay. We show that all compounds displayed an inhibitory effect on ACE2 activity, the six most promising candidates exhibiting IC50 values in the range of 62-179 microM.

Angiotensin-Converting Enzyme 2↗