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Biomedical subjects

S Strack

Publications and source records attributed to S Strack.

At least 37 records · Page 2Linked to original sources
PubMed1997

Association of brain protein phosphatase 1 with cytoskeletal targeting/regulatory subunits.

Protein phosphatase 1 catalytic subunit (PP1C) is highly enriched in isolated rat postsynaptic densities. Gel overlay analyses using digoxigenin (DIG)-labeled PP1C revealed four major rat brain PP1C-binding proteins (PP1bps) with molecular masses of approximately 216, 175, 134, and 75 kDa, which were (1) more abundant in brain than other rat tissues; (2) differentially expressed in microdissected brain regions; and (3) enriched in isolated cortex postsynaptic densities. PP1bp175, PP1bp134, PP1bp75, and PP1C were partially released from forebrain particulate extracts by incubation at low ionic strength, which destabilizes the actin cytoskeleton. Size-exclusion chromatography of solubilized extracts separated two main PP1 activities (approximately 600 and approximately 100 kDa). PP1bps and PP1C gamma1 were enriched in the approximately 600-kDa peak, but PP1C beta was enriched in the approximately 100-kDa peak. Furthermore, PP1bp175 and PP1bp134 exhibited lower binding of recombinant DIG-PP1C beta than recombinant DIG-PP1C gamma1 or DIG-PP1C alpha. Solubilized PP1bp175 and PP1bp134 interact with PP1C under native conditions, because they both (1) coeluted from size-exclusion and ion-exchange columns; (2) bound to microcystin-LR-Sepharose; and (3) coprecipitated using PP1C antibodies. Trypsinolysis of the approximately 600-kDa form of PP1 increased phosphorylase a phosphatase activity approximately fourfold, suggesting that interaction of PP1C with these PP1bps modulates its activity. Thus, brain PP1 activity is likely targeted to the cytoskeleton, including postsynaptic densities, by isoform-selective binding of PP1C to these targeting/regulatory subunits, contributing to the specificity of its physiological roles.

Animals↗
PubMed1997

Development of oral hygiene self-efficacy and outcome expectancy questionnaires.

In order to measure social cognitive constructs in the oral hygiene domain, questionnaires containing self-efficacy and outcome expectation items were developed. Items were generated to measure personal beliefs in brushing and flossing ability under a variety of circumstances, and expected outcomes from performing oral hygiene behaviors that might be positive, negative, primary and secondary. In the first study, factor scales were developed on the basis of the responses from 90 subjects awaiting dental treatment. Principal components analyses with varimax rotation revealed two self-efficacy and four outcome expectations dimensions that explained 73% and 51% of the variance, respectively. A second study that utilized 103 government employees was conducted to evaluate the psychometric properties of the questionnaires. All scales demonstrated good internal consistency and test-retest stability. Correlations with extra test measures provided preliminary evidence for the validity of the instruments.

Adult↗
PubMed1997

Invited essay: the challenge of differentiating normal and disordered personality.

By separating personality disorders from other psychiatric conditions and requiring mental health professionals to assess the personalities of all their patients, DSM-III Axis II created an explosion of ideas and research on the nature and structure of personality. Since 1980, theorists and researchers from previously segregated camps have come together to address a number of important taxonomic issues, including the relationship between normal and disordered character. In this article, we place the challenge of differentiating normal and abnormal personality in historical perspective, and outline major theories, models, and methods that inform personologists in their quest. The complexity of personality, and the differences in the way people view the subject matter, ensure that there will be several research lines in the next generation. Progress in the field can be quickened by refinements in theory, the development of more assessment instruments that tap both normal and abnormal traits, and empirical studies that follow well-match groups of normals and patients over significant time periods.

Comorbidity↗
PubMed1996

Localization of the calcium/calmodulin-dependent protein phosphatase, calcineurin, in the hindbrain and spinal cord of the rat.

The calcium/calmodulin-dependent protein phosphatase calcineurin was localized at the light microscopic level in the rat hindbrain and spinal cord by using an antibody against the alpha-isoform of the catalytic subunit. Calcineurin was highly concentrated in axons, dendrites, and cell bodies of a subpopulation of alpha-motoneurons in hindbrain motor nuclei and the lateral motor column along the length of the spinal cord. These calcineurin-positive alpha-motoneurons appeared to be randomly distributed and represented approximately 25% of the total alpha-motoneuron pool in the motor trigeminal nucleus and the spinal cord lateral motor column. Within the facial nucleus, calcineurin-containing motoneurons were present in the medial and dorsal subdivision but not in the lateral and intermediate subdivision. In addition to the enrichment in motoneurons, calcineurin was enriched in cells of the superficial laminae of the spinal cord dorsal horn and its extension into the medulla, the caudal spinal trigeminal nucleus. Axonal staining in the white matter of the spinal cord was generally weak, except in the dorsolateral funiculus, where strongly calcineurin-positive axons formed a putative ascending tract that appeared to terminate uncrossed in the caudal lateral reticular nucleus of the medulla. This tract may originate from calcineurin-positive cells in the dorsolateral funiculus. We also compared the distribution of calcineurin with calcium/calmodulin-dependent kinase II in the spinal cord and found that the kinase is more widely expressed. Thus, calcineurin is highly restricted to a few locations in the hindbrain and spinal cord. Selective staining in facial subnuclei that innervate phasically active muscles suggests that calcineurin-positive motoneurons represent a subset of alpha-motoneurons innervating a metabolic subtype of muscle fibers, possibly fast-twitch fibers.

Animals↗
PubMed1994

Personality profiles of police candidates.

Recently, Eber (1991) reported on several large-scale studies of law enforcement candidates. The main measures were the two parts of the Clinical Analysis Questionnaire (Krug, Cattell, & IPAT, 1980). Part I consists of the 16 Personality Factor Questionnaire Scales, while Part II is devoted to 12 measures of psychopathology. The most striking finding was a clear personality profile characterized by a strong pattern of self-discipline or Control, Tough Poise, and low Anxiety. Our study hypothesis was that several police personality profiles would be found. This conjecture was tested on the 16PF scores of two samples of 275 police candidates by means of the Ward (1963) hierarchical clustering procedure and the Milligan/Sokal (1980) nonhierarchical K-means cluster procedures. Three distinct score profiles were isolated in both samples.

Adult↗
PubMed1993

Antiserum to an eye-specific protein identifies photoreceptor and circadian pacemaker neuron projections in Aplysia.

The marine gastropod Aplysia has a circadian clock in each eye that generates a circadian rhythm of optic nerve activity. The axons of pacemaker neurons carry the rhythmic activity to the brain where it can be recorded from various ganglionic connectives as it is distributed throughout the CNS. We had previously identified an eye-specific 48-kD protein using an antiserum, anti-S, that recognizes the period gene product of Drosophila. We have now obtained two partial amino acid sequences of the 48-kD protein and raised a polyclonal antiserum using a synthetic peptide with the amino acid sequence of one of them. The antiserum recognizes a family of spots of M(r) 47-48 kD and Pi 5.9-6.0 on 2D immunoblots of eye proteins. The immunoblot staining intensity does not exhibit a circadian rhythm. Used in immunocytochemistry, the antiserum recognizes fibers in the optic nerve and retinal neuropil, pacemaker neurons, certain photoreceptors, and the photoreceptor rhabdom layer. It stains the optic nerve fibers and optic fiber terminals in the cerebral optic ganglion and recognizes the cerebral optic tracts, putative synaptic exchange areas, and optic tract projections from the cerebral ganglion into various head nerves and interganglionic connectives. The function of the 48-kD protein is not known but it could be involved in the maintenance or regulation of the retinal afferent pathways, including the pacemaker neuron axons, known from previous axonal transport and electrical recording studies to be the circadian output pathway.

Amino Acid Sequence↗
PubMed1993

Organically bound tritium.

Tritium released into the environment may be incorporated into organic matter. Organically bound tritium in that case will show retention times in organisms that are considerably longer than those of tritiated water which has significant consequences on dose estimates. This article reviews the most important processes of organically bound tritium production and transport through food networks. Metabolic reactions in plant and animal organisms with tritiated water as a reaction partner are of great importance in this respect. The most important production process, in quantitative terms, is photosynthesis in green plants. The translocation of organically bound tritium from the leaves to edible parts of crop plants should be considered in models of organically bound tritium behavior. Organically bound tritium enters the human body on several pathways, either from the primary producers (vegetable food) or at a higher tropic level (animal food). Animal experiments have shown that the dose due to ingestion of organically bound tritium can be up to twice as high as a comparable intake of tritiated water in gaseous or liquid form. In the environment, organically bound tritium in plants and animals is often found to have higher specific tritium concentrations than tissue water. This is not due to some tritium enrichment effects but to the fact that no equilibrium conditions are reached under natural conditions.

Animals↗
PubMed1993

Some NEO-PI five-factor personality profiles.

The aim of this study was to identify any clusters of score profiles to be found in a college sample of 236 subjects administered the five-factor NEO [Neuroticism, Extroversion, Openness] Personality Inventory (Costa & McCrae, 1985). Application of Ward's agglomerative hierarchical procedure to the score profiles disclosed six clusters that were replicated in a K-means partitioning process. The six clusters were then compared by a one-way analysis of variance (ANOVA) with respect to their mean five higher order scores on the Interpersonal Style Inventory (Lorr, 1986). The highly significant F tests provided confirmation of the characteristics of the cluster profiles isolated.

Journal Article↗
PubMed1992

Profile clusters for men and women on the personality adjective check list.

This study examined the major personality profiles found for men and women on the Personality Adjective Check List (Strack, 1991b). Subjects were 1,058 men and 1,194 women from a number of samples of normal adults (Strack, 1991b). Ward's (1963) agglomerative hierarchical procedure yielded five clusters for men and four for women that were replicated in subsequent K-means nonhierarchical analyses. Correlates of cluster membership obtained from subgroups of subjects on four personality measures provided strong evidence for the classification.

Journal Article↗
PubMed1991

Factor analysis of MCMI-II and PACL basic personality scales in a college sample.

This study examined factor dimensions common to the eight basic personality scales of the Millon Clinical Multiaxial Inventory-II (MCMI-II; Millon, 1987) and Personality Adjective Check List (PACL; Strack, 1987, 1990). Subjects were 140 college students (65 men and 75 women). MCMI-II weighted raw scores (WRS) and WRS corrected for number of items endorsed true by regression were employed for analysis along with PACL T-scores. Principal components analyses with varimax and direct oblimin rotations were carried out separately on the two sets of MCMI-II and PACL scores. MCMI-II and PACL scales measuring the same personalities were usually correlated most highly with each other, although some divergences were noted. WRS yielded three bipolar dimensions and a fourth unipolar method factor that loaded only the five MCMI-II scales that were strongly correlated with number of items endorsed true. Residual scores yielded a more meaningful set of three bipolar dimensions labeled Social Introversion-Extraversion, Emotionality-Restraint, and Social Dominance-Submissiveness, without the method factor, that were very similar to personality dimensions found separately in the two tests. More research is needed to clarify the response bias issue in the MCMI-II and to further explicate similarities and differences between the MCMI-II and the PACL.

Journal Article↗
PubMed1990

Profile clusters of the MCMI-II personality disorder scales.

An analysis was conducted to identify the major personality disorder score profiles to be found in the Millon Clinical Multiaxial Inventory II. Application of Ward's agglomerative hierarchical procedure to two subsamples of psychiatric patients (n = 83 for each) yielded four replicated subgroups. A subsequent K-means nonhierarchical approach confirmed four of the Ward clusters. Three subgroups can be characterized as (a) Antisocial, Aggressive (Sadistic), and Passive-Aggressive; (b) Avoidant, Schizoid, and Self-Defeating, and (c) Schizoid, Dependent, and Compulsive. A fourth sizable group is comprised of patients with flat profiles.

Adjustment Disorders↗
PubMed1990

Personality and symptom dimensions of the MCMI-II: an item factor analysis.

The self-reports of a sample of 248 male psychiatric patients on the MCMI-II (Millon, 1987) were factor analyzed at the item level. Principal components analyses with both Varimax and Direct Oblimin rotations were carried out separately on 120 personality disorder items and 51 clinical symptom items. As judged by the scree test, seven factors accounted for the personality disorder items, and five factors accounted for the symptom items. The personality disorder factors were interpreted as Schizotypal, Social Introversion vs. Extraversion, Conformity, Submissive vs. Aggressive, Antisocial, Narcissism, and Hostile Aggression. The symptom factors were hypothesized to represent Depression/Anxiety, Alcohol Dependence, Suicidal Ideation, Hypomania, and Drug Dependence. Agreement with a similar analysis of the MCMI-I was close.

Adult↗
PubMed1990

Item factor structure of the Personality Adjective Check List.

This study reports on a principal-components analysis of the Personality Adjective Check List (PACL) at the item level. Data came from a national sample of normal adults and included the responses of 1,058 men and 1,194 women (N = 2,252). Analyses were conducted separately for men and women, and for the sexes combined. The scree test was applied to decide on the number of factors to extract. Retained factors were rotated by varimax and direct oblimin procedures. Results were very similar for each analysis, with coefficients of congruence for the five orthogonal factors obtained from men and women separately being .95, .92, .94, .94, and .92. The five unipolar personality dimensions isolated were interpreted as Aggressive/Dominant, Neurotic, Conscientious, Detached/Introverted, and Surgent/Extraverted. These were compared to item factors of the Million Clinical Multiaxial Inventory (MCMI-I), MCMI-II, Adjective Check List (ACL), and to Norman's Big Five dimensions.

Adolescent↗
PubMed1989

An antibody to the Drosophila period protein recognizes circadian pacemaker neurons in Aplysia and Bulla.

The molecular mechanisms of the pacemakers underlying circadian rhythms are not well understood. One molecule that presumably functions in the circadian clock of Drosophila is the product of the period (per) gene, which dramatically affects biological rhythms when mutated. An antibody specific for the per protein labels putative circadian pacemaker neurons and fibers in eyes of two marine gastropods, Aplysia and Bulla. As was found for the Drosophila per protein, there is a daily rhythm in the levels of the per-like antigen in Aplysia eyes. Thus, certain molecular features of the per protein, as well as aspects of the temporal regulation of its expression, may be conserved in circadian pacemakers of widely divergent species.

Animals↗
PubMed1989

Coping with conflict situations: middle-aged and elderly men.

In this study we investigated the coping responses of fairly healthy, middle-aged (40-64 years, n = 76) and elderly (65-92 years, n = 106) men to five conflict situations (i.e., decision making, defeat in a competitive circumstance, frustration, authority conflict, and peer disagreement). Coping responses were measured by the Life Situations Inventory, developed to assess three forms of coping: problem-solving, avoidance, and resignation. Scales were based on a 28-item questionnaire and were derived rationally through item analysis. Alpha coefficients ranged from .75 to .82. Elderly subjects used avoidance significantly less often than did middle-aged subjects in handling decision-making and authority-conflict situations. No differences were noted between the age groups in use of problem solving or resignation. Both middle-aged and elderly persons favored use of problem solving in managing all conflicts. Results suggest that studies that do not address potential interactions between age and stress situation may be missing an important element in the age-coping relation.

Adaptation, Psychological↗
PubMed1987

Degree of life-threat and differential use of coping modes.

This investigation sought to determine whether medical patients facing life-threatening illnesses (i.e. cancer, myocardial infarction) differed in their coping responses from medical patients facing nonlife-threatening illnesses (e.g. arthritis, dermatitis). Subjects' coping responses were measured by a Medical Coping Modes Questionnaire which was developed to measure three forms of coping: confrontation, avoidance, and acceptance-resignation. The scales were based on a 32-item questionnaire and were derived by a combination of rational and factor analytic procedures. Construct validity data gathered from patients, physicians, and significant others verified the nature of the scales. Results indicated that life-threatened patients used confrontation significantly more than did nonlife-threatened patients in dealing with their illness. Acceptance-resignation was used least of all by each of the groups. Findings appear to support those theorists who conceptualize coping behavior in dealing with life-threat as being shaped more by situational context than by personal style.

Adaptation, Psychological↗
PubMed1987

Predicting successful completion of an aftercare program following treatment for alcoholism: the role of dispositional optimism.

In this study we investigated several variables as potential predictors of success in completing a transition program after treatment for alcoholism. Subjects were 54 men who had completed a 30-day treatment program and who were subsequently admitted to a 90-day inpatient aftercare program. The outcome measure was successful completion of this latter program. Predictor variables were dispositional optimism, hassles, uplifts, and several demographic variables. Optimism was positively associated with successful outcome. The simple association between uplifts and outcome also approached significance, but in the opposite to expected direction. Discriminant analyses used both of these variables, as well as age and education level, as predictors of successful outcome. There was no evidence of a role for hassles. Discussion centers on the importance of dispositional optimism as a predictor of successful adaptation in a variety of behavioral domains.

Adaptation, Psychological↗