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 145 records · Page 8Linked to original sources
PubMed1986

The NCI Drug Information System. 2. DIS Pre-Registry.

The Pre-Registry Module of the Drug Information System (DIS) is a staging area through which all new compounds are passed prior to acquisition and testing. Several methods are available for the entry of structures into the Pre-Registry; all involve built-in data validation. Newly entered structures are examined by computer programs for structural novelty and potential for anticancer activity. For those compounds that proceed to acquisition, the various acquisition steps, such as letter writing and record updating, are performed automatically. When a sample is obtained, the entire Pre-Registry record is updated and moved forward into the permanent DIS chemistry files.

Antineoplastic Agents↗
PubMed1976

Empirical validation of diagnostic similarities from a structural perspective.

In an effort to establish definitive patterns of patient variables for the diagnostic categories used by psychiatry, this study investigated the similarity between diagnostic classes as perceived by psychiatrists when evaluating patients from their own caseloads. A grid method was used to evaluate the diagnostic process. Thirteen psychiatrists rated their own patients on the constructs generated from their own personal dimensions. An overall analysis of the data demonstrated that patients within a diagnostic category were seen as more similar to one another than were patients from different diagnostic categories. Similarities between diagnostic classes showed that neurotic/situational maladjustment, personality disorder/alcoholic, and psychotic/alcoholic were the most similar pairs of unlike diagnoses. Examination of the process of diagnosis showed the functional similarity between some diagnostic classes. Specific areas of diagnostic similarity were present in a system that produced overall diagnostic clarity. Implications for the use of the grid method in psychiatric training were discussed.

Alcoholism↗
PubMed1992

Selection criteria for brief dynamic psychotherapy: reliability, factor structure and long-term predictive validity.

Forty outpatients were evaluated for psychotherapy with a modified version of Sifneos' selection criteria for brief dynamic psychotherapy. Reliabilities were acceptable for most items when the ratings of 4 clinical judges were averaged. A factor analysis of the reliable items produced four of the five dimensions of suitability proposed by Sifneos and others: circumscribed focus, motivation, flexible interaction, quality of interpersonal relations. A combination of these dimensions were more significant predictors of long-term dynamic change than background and DSM-III axis I-V variables. Problem solving capacity (use of self-understanding) before treatment could not be reliably rated and was accordingly not tested as a possible fifth dimension of suitability.

Anxiety Disorders↗
PubMed1986

Structure predictions and surface charge of nitrogenase flavodoxins from Klebsiella pneumoniae and Azotobacter vinelandii.

A first approximation to the tertiary structure of the nitrogenase flavodoxins of Klebsiella pneumoniae and Azotobacter vinelandii can be obtained by superimposing their amino acid sequences upon the crystallographically determined structure of the long-chain flavodoxin from Anacystis nidulans. This procedure is validated by secondary structure predictions based on the sequence alone and by the distribution of polar and hydrophobic residues. It reveals, among other things, a distinctive distribution of surface charge peculiar to the nitrogenase flavodoxins, which is probably important in determining the kinetics of electron transfer with their physiological redox partners. The most likely positions of the phosphodiester bridge which has been described in the A. vinelandii molecule can also be assessed.

Amino Acid Sequence↗
PubMed1991

The structured oral examination as a method for assessing surgical residents.

The purpose of this study was to determine the overall reliability, inter-rater reliability, and criterion validity of the structured oral examination (SOE) for assessing surgical residents. An SOE consisting of four predetermined clinically oriented scenarios was administered to 23 second postgraduate year surgical residents. Each scenario had five to six questions, each with a specific marking scheme. Candidates were assessed by two examiners and scores were derived independently. Overall reliability (Cronbach's alpha) was 0.75. Inter-rater reliability was significant for each pair of examiners and each question (r = 0.78 to 0.91: p less than 0.0001). Criterion validity was measured by correlating SOE scores with multiple-choice examination (MCQ) and objective structured clinical examination (OSCE) scores. Correlations between the SOE and MCQ and OSCE were significant and fell into the moderate range (0.48 to 0.51). The results of this study show that the SOE is useful in the assessment of clinical knowledge and problem-solving abilities of the surgical resident. Overall and inter-rater reliabilities achieved exceed those of traditional oral examination formats.

Adult↗
PubMed1979

Validity of medical staff judgments in establishing quality assurance priorities.

The validation of a structured group judgment procedure to establish priorities for quality assurance activities was undertaken in six medical institutions in the United States. Validation focused on the extent to which health improvement could be documented by outcome-based projects focusing on priority topics. Predictive (criterion-related) validity was sought by analyzing five successively more stringent levels of evidence: 1) feasibility of implementing a quality assessment project within the topic areas selected by the prioity procedure; 2) accuracy of identifying health deficiencies or strengths; 3) verification of establishing correctable causes of health deficiencies; 4) capability of effecting significant improvement of health deficiencies; and 5) credibility of evidence that improvement achieved is directly attributable to corrective actions taken. Within the limits of generalizability, predictive validity was documented at every level of analysis. It is recommended that the structured group judgment process used in this study be more thoroughly evaluated and considered for quality assurance planning purposes.

Decision Making↗
PubMed1990

Situation-response (S-R) questions for identifying the function of problem behaviour: the example of thumb sucking.

The purpose of this study was to construct and validate the prototype of a structured interview or questionnaire for use in the functional assessment of problem behaviour. A set of situation-response (S-R) questions was used to test hypotheses concerning discriminative stimuli SD, inhibitive stimuli (SI) and the function of a problem behaviour (R). The situations in S-R questions include stimuli which are expected (a) to set the occasion for, or (b) to inhibit the problem behaviour. The response part includes the problem behaviour as well as behaviour patterns with known functions. The problem behaviour is correlated with those behaviour patterns whose functions it shares. For the study of 26 children suffering from orthodontal problems due to excessive thumb sucking, a structured interview was developed and validated for identifying (a) stimuli (SD) that trigger excessive thumb sucking (problem behaviour), (b) stimuli (SI) that inhibit this response, and (c) the function of thumb sucking.

Adaptation, Psychological↗
PubMed1991

Predicted three-dimensional structure of the protease inhibitor domain of the Alzheimer's disease beta-amyloid precursor.

Alzheimer's disease is characterized by the deposition of amyloid beta-protein as plaques and tangles in the brains of its victims. The amyloid precursor can be expressed with or without the inclusion of a protease inhibitor domain, the potential role of which in amyloidogenesis has prompted the generation of a model of its three-dimensional structure based on the known structure of a related inhibitor. The model structure predicts that the mutated residues are almost entirely on the surface of the inhibitor domain, while conserved residues constitute the hydrophobic core. In addition, several pairs of structurally complementary, or concerted, mutations are seen. These structural features provide strong evidence for the validity of the modeled structure, and it is suggested that the presence of complementary mutations may be used as a criterion for evaluating protein structures built by homology, in addition to the (spatial) location of the mutations. The terminal residues delimiting the domain are among those furthest from the protease binding site and are in close proximity to one another, thus suggesting the ability of the domain to function as a structural cassette within the context of a larger protein. The electrostatic potentials of the inhibitor and of the related bovine pancreatic trypsin inhibitor reveal how two inhibitors with very different net charges can bind with approximately the same binding constant to trypsin and suggest a mutation of trypsin that might selectively enhance the binding of the amyloid inhibitor domain. The model provides a structural basis for understanding the functional roles of residues in the domain and for designing simpler molecules to test as pharmacologic agents for intervention in Alzheimer's disease.

Amino Acid Sequence↗
PubMed1987

Correlations between active zone ultrastructure and synaptic function studied with freeze-fracture of physiologically identified neuromuscular junctions.

The active zone is a unique presynaptic membrane specialization that is believed to be the site of neurotransmitter release. To examine directly the relationship between active zone ultrastructure and synaptic efficacy, frog neuromuscular junctions were studied with a new technique combining electrophysiology, light microscopy, and freeze-fracture of identified single muscle fibers. This technique allows correlations to be made between quantal content (measured in low Ca2+ and high Mg2+ Ringer solution), endplate size, and active zone structure at the same neuromuscular junctions. By measuring physiological and morphological variables at the same junctions, the validity of structure-function correlations is significantly improved. Synaptic quantal content in 91 physiologically identified muscle fibers varied considerably and was only poorly correlated with endplate size, as shown in previous studies. To measure the total length of endplate branches, either a modified cholinesterase stain or rhodamine-labeled peanut agglutinin stain was used. When the same identified muscle fibers were freeze-fractured, active zones were exposed in 17 junctions. In a replica that contained a large part of one nerve terminal, there was no detectable gradient in active zone structure along the length of 3 different nerve terminal branches identifiable with both light and electron microscopy. The results from these 17 identified junctions indicate that quantal content per unit terminal length is positively correlated with the amount of active zone per unit terminal length. The estimated total active zone length and total number of active zone particles per junction are also positively correlated with the quantal content in these identified junctions. This study suggests that active zone size and spacing are better indicators of transmitter release than is endplate size and that the active zone may play an important role in regulating synaptic efficacy at the neuromuscular junction.

Animals↗
PubMed1990

Two promising shame and guilt scales: a construct validity comparison.

This study compared the validity of two promising measures of shame and guilt proneness: revisions of the Harder Personal Feelings Questionnaire (PFQ2; Harder & Lewis, 1987) and the Hoblitzelle Adapted Shame and Guilt Scale (ASGS; Hoblitzelle, 1982). Internal consistency, test-retest stability, factor structure, and construct validity with convergent and discriminant personality dimensions were examined for both scales. In addition to the shame and guilt measures, 63 (37 male, 26 female) mostly freshman college students completed a randomly ordered battery of personality scales theoretically relevant to shame and guilt proneness. Results support the reliability and shame/guilt factor structure of each scale. ASGS Shame correlations appeared marginally more valid with 11 external construct variables than PFQ2 Shame, whereas PFQ2 Guilt was clearly more valid than its corresponding ASGS subscale. New, potentially improved scales were constructed from the factor analyses and from item analyses. However, the resulting scales did not show improved validity.

Adolescent↗
PubMed1992

Molecular conformation of ubiquitinated structures and the implications for regulatory function.

The molecular conformation of ubiquitinated structures and the validity of the N-end rule were examined by simulating the molecular mechanics to ascertain the global energy-minimized structure. We examined the chemical linkage involved in attaching the ubiquitin carboxyl terminus to the N-terminus of three different x-hexapeptides, where x is the amino group of the acceptor peptide--either valine, arginine or glutamic acid--(x-K linkage) and to the epsilon-amino group of lysine of the acceptor hexapeptide x-glu1-his2-lys3-gly4-lys5-val6 (K-K linkage) through the formation of an isopeptide bond. Changes in conformation and molecular stability of the multi-ubiquitinated structures were determined by energy-minimization procedures using the SYBYL program developed by Tripos Associates. In the x-K linkage, the ubiquitin molecule is stretched in the beta-pleated sheets and beta-turns while the alpha-helices expand, as the molecule continues to unfold linearly. In the K-K linkage, the ubiquitin molecules have turned into a u-shaped, semi-circular alignment, contracting into a compact, folded structure.

Amino Acid Sequence↗
PubMed1991

Factor structure of the Motivation Assessment Scale for persons with mental retardation.

The rating scale used to assess the motivators of maladaptive behaviors in persons with mental retardation was the Motivation Assessment Scale. In the current study, we validated the factor structure of the scale on a sample of 118 subjects with predominately severe or profound mental retardation. They exhibited deviant behaviors such as self-injurious and tantrum behavior, aggression, and passivity. The results of the factor analysis with varimax rotation validated the assumptions of the developers of the scale that the motivators could be grouped into sensory, escape, attention, and tangible reinforcers. These four subscales are easily interpretable and should continue to provide valuable information.

Adult↗
PubMed1986

On drawing inferences about the structure of normal cognitive systems from the analysis of patterns of impaired performance: the case for single-patient studies.

An analysis of the logic of valid inferences about the structure of normal cognitive processes from the study of impaired cognitive performance in brain-damaged patients is presented. The logic of inferences from group studies and single-case studies is compared. It is shown that given certain assumptions, only the single-case method allows valid inferences about the structure of cognitive systems from the analysis of impaired performance. It is also argued that although the single-case approach is not entirely problem-free, the difficulties encountered are relatively minor.

Brain Damage, Chronic↗
PubMed1984

Convergent validity of type A behavior pattern scales and their ability to predict physiological responsiveness in a sample of female public employees.

The purpose of this study was to assess the construct validity of the structured interview (SI), Jenkins Activity Survey (JAS), Thurstone Activity Scale, and Bortner Type A Scale in a sample of female employees from a government service agency. Criteria for validity assessment were physiological reactance to a mental stressor, psychological strains experienced at work, physical symptoms associated with work, and urinary catecholamine production at work. A continuous Type A SI scale demonstrated better convergent and construct validity than did the SI category scores. All of the SI Type A scales were reliable. Among the questionnaire measures only the Thurstone Activity Scale was reliable and showed the strongest construct validity. The SI measures of Type A tended to correlate with physiological responsiveness (changes in heart rate, skin temperature, and skin conductance), while the questionnaire measures correlated with self-reports of job strains (satisfaction, irritation, depression, physical symptoms), thus indicating the operation of measurement artifacts in validity assessment. No significant correlations were obtained between Type A and catecholamines. Comparison of correlation analysis with subgroup analysis revealed the former to be a more powerful test of the relationships that may exist between Type A behavior pattern and relevant criteria.

Adult↗
PubMed1990

Improvements in protein secondary structure prediction by an enhanced neural network.

Computational neural networks have recently been used to predict the mapping between protein sequence and secondary structure. They have proven adequate for determining the first-order dependence between these two sets, but have, until now, been unable to garner higher-order information that helps determine secondary structure. By adding neural network units that detect periodicities in the input sequence, we have modestly increased the secondary structure prediction accuracy. The use of tertiary structural class causes a marked increase in accuracy. The best case prediction was 79% for the class of all-alpha proteins. A scheme for employing neural networks to validate and refine structural hypotheses is proposed. The operational difficulties of applying a learning algorithm to a dataset where sequence heterogeneity is under-represented and where local and global effects are inadequately partitioned are discussed.

Artificial Intelligence↗
PubMed1982

Theory into hospital practice: a pilot implementation.

Implementing the Adaptation Model required that the model's concepts be explicitly identified, defined, and understood. Guidelines, standards and tools had to be revised or developed. Effective nursing administration leadership and the personal and professional commitment of administrators, educators, and staff nurses to the goal were necessary ingredients. The abstract nature of theory often requires sheer determination and hard thinking if it is to be effectively applied to practice. A formal education process must also be dynamic and ongoing. Project members continue to gain greater insight into the model's structure, identify problems in its application, and seek ways to solve them. Their combined, concentrated efforts have proved a cost-effective way to close gap between education and practice. The project's initial outcomes, increased patient satisfaction and expanded professional nursing, support the application of the Adaptation Model in our hospital. Further validation of its structure and the value of its outcomes, however, needs additional study, and extended application in multiple practice settings. Validation of the Roy Adaptation Model or any of the evolving conceptual frameworks for nursing practice requires use, input, and evaluation by nurses in all settings. Opening the theoretical domain to hospital nurses needs the support and leadership of nursing and hospital administrators.

Adaptation, Psychological↗
PubMed1980

[Hematomorphological differential diagnosis of small cell lymphoma. What is the atypical chronic lymphadenosis?].

More importance is being attached to haematologic cell morphology, particularly in the field of small-cell non-Hodgkin lymphomas. This shifting of diagnostical validity from the structural substrate to the cellular one can clearly be illustrated by the transition of classification according to Rappoport to that according to Lennert (Kiel-classification). Here minute cytomorphological criteria acquire a new validity by their significance in the microscopic cut preparation and in the electron-microscope as well as by their correlation to cell-immunological parameters. Thus, it is possible to make a differential diagnostics of the extending small-cell lymphomas from the blood picture. It enables an ensured morphological differentiation to be made for typical B-lymphadenosis, prolymphocytic leukaemia, T-cell lymphadenosis, lymphoplasmocytoid immunocytoma, centrocytoma, and hairy cell leukaemia. The relevance of this differentiation can be further identified by a consequent immunologic cell characterization.

Cytodiagnosis↗