Biomedical subjects

R A Bryant

Publications and source records attributed to R A Bryant.

At least 19 recordsLinked to original sources

PubMed2002

Hyperarousal and dissociation: a study of novice skydivers.

Peritraumatic dissociation describes alterations in awareness that occur during or immediately after a trauma. This study investigated a simulated form of peritraumatic dissociation by indexing the responses of skydivers (N=100) who were participating in their first skydive. Prior to jumping, participants completed the Beck anxiety inventory, the Tellegen absorption scale, and ratings of predictability and uncontrollability. Immediately after the jump, they completed the peritraumatic dissociative experiences questionnaire and the physical reactions scale. Responses indicated that the skydive elicited extreme anxiety, hyperarousal, and peritraumatic dissociation in a significant proportion of skydivers. Multiple regression analyses indicated that hyperarousal, and to a lesser extent anxiety, were strongly predictive of peritraumatic dissociative reactions. These results are discussed in terms of proposals that peritraumatic dissociation is mediated by hyperarousal.

Adolescent↗

PubMed2001

Panic symptoms during trauma and acute stress disorder.

This study investigated the role of panic symptoms that occur during trauma and subsequent acute stress disorder (ASD). Civilian trauma (N=51) survivors with either acute stress disorder (ASD), subclinical ASD, or no acute stress disorder (non-ASD) were administered the Acute Stress Disorder Scale, Impact of Event Scale, Beck Anxiety Inventory, Beck Depression Inventory, and the Anxiety Sensitivity Index (ASI). Participants also completed the Physical Reactions Scale to index panic symptoms that occurred during their trauma. Overall, 53% of participants reported panic attacks during their trauma. ASD and subclinical ASD participants reported more peritraumatic panic symptoms, and higher ASI scores, than non-ASD participants. These findings are consistent with the notion that peritraumatic panic may be related to subsequent posttraumatic stress, and suggest that modification of maladaptive beliefs about physical sensations should be addressed in posttraumatic therapy.

Adult↗

PubMed2001

Posttraumatic stress disorder and traumatic brain injury: can they co-exist?

The possibility that posttraumatic stress disorder (PTSD) can develop following traumatic brain injury (TBI) has been the subject of considerable debate. The traditional view has held that impaired consciousness that occurs with TBI precludes encoding of the traumatic experience, and this prevents subsequent reexperiencing symptoms. This paper critically reviews available, empirical studies on PTSD in TBI populations and suggests that these two conditions can co-exist. The various mechanisms that may mediate PTSD following TBI are discussed, and special attention is given to issues that recognize the distinctive features of PTSD following TBI. These processes include implicit processing, biologically mediated fear conditioning, and reconstruction of trauma memories. Finally implications for assessment, treatment, and forensic investigation of PTSD in TBI populations are, addressed. This review concludes that TBI populations provide a useful means by which the role of traumatic memories (and impaired memories) in posttraumatic adjustment can be studied.

Adaptation, Psychological↗

PubMed2001

Reconstructing trauma memories: a prospective study of "amnesic" trauma survivors.

The purpose of this study was to investigate memory for trauma in patients who were initially amnesic of the trauma as a result of mild traumatic brain injury (MTBI). Motor vehicle accident survivors who sustained a MTBI were assessed for their memory within 1-month posttrauma (n = 79) and again at 2-years posttrauma (n = 50). Consistent with their brain injury, all patients reported significant amnesia of their accident at initial assessment. At 2-year posttrauma, 40% were able to remember their accident. Reporting memory for the trauma was associated with shorter duration of posttraumatic amnesia. These findings suggest that people reconstruct memories of trauma in the absence of complete encoding of the experience. Possible mechanisms for memory reconstruction are considered.

Accidents, Traffic↗

PubMed2001

Posttraumatic stress disorder and mild brain injury: controversies, causes and consequences.

Posttraumatic stress disorder (PTSD) is an anxiety condition that often arises following a traumatic experience. It has commonly been argued that impaired consciousness associated with mild brain injury (MBI) precludes encoding of the traumatic experience, and this prevents PTSD development. This review considers the available evidence on PTSD following MBI and indicates the distinctive nature of PTSD after MBI. The review then discusses the possible mechanisms that may mediate PTSD in this population. The interaction of PTSD and postconcussive symptoms is discussed within a cognitive model that emphasizes the role of catastrophic interpretations of postconcussive symptoms. Finally, the implications of PTSD after MBI for assessment and treatment are reviewed.

Adaptation, Psychological↗

PubMed2001

Hypnotically induced emotional numbing.

This study investigated the utility of a hypnotic suggestion to inhibit emotional response. High and low hypnotizable participants (N = 53) were administered a hypnotic induction, and half the participants were then administered a suggestion for emotional numbing. Participants were then presented with slides depicting neutral or disfigured faces. Participants who received the emotional numbing suggestion reported less responsivity to the disfigured faces than did those in the control condition, and this pattern was stronger for high than for low hypnotizable participants. Highs in the numbing condition displayed less overall distress in their facial expressions in response to the disfigured slides relative to those in the control condition. These findings suggest that hypnotic emotional numbing may be a useful paradigm in which to explore processes in emotion inhibition.

Adult↗

PubMed2001

Posthypnotic amnesia for material learned before or during hypnosis: explicit and implicit memory effects.

This article focuses on dissociations between explicit and implicit expressions of memory during posthypnotic amnesia (PHA). Despite evidence of such dissociations, experimental design in this area has not always been consistent with contemporary memory research. Within a paradigm that aimed for conceptual and methodological clarity, we presented 40 high and 38 low hypnotizable individuals with a word list either before or during hypnosis, gave them a PHA suggestion for the word list, and tested them on explicit and implicit memory tasks. In the absence of conscious recollection, highs showed equivalent levels of priming (perceptual and semantic) to lows. However, when analysis focused only on those highs who remained amnesic after the implicit memory tasks, we confirmed perceptual, but not semantic, priming. These findings highlight the impact of methodological choices on theoretical interpretations of memory performance following a suggestion for PHA.

Adolescent↗

PubMed2001

Hypnotic color blindness and performance on the Stroop test.

A suggestion for hypnotic color blindness was investigated by administering a reverse Stroop color-naming task. Prior to the suggestion for color blindness, participants learned associations between color names and shapes. Following the color blindness suggestion, participants were required to name the shapes when they appeared in colors that were either congruent or incongruent with the learned associations. The 18 high hypnotizable participants who passed the suggestion were slower to name (a) shapes in which the color name was incongruent with the color in which it was printed, (b) "unseen" rather than "seen" shapes, and (c) color-incongruent shapes that were printed in the color in which they were "color-blind." These patterns are discussed in terms of potential cognitive and social mechanisms that may mediate responses to hypnotic color blindness.

Color Vision Defects↗

PubMed2001

Posttraumatic stress disorder and psychosocial functioning after severe traumatic brain injury.

The aim of this study was to investigate the influence of posttraumatic stress disorder (PTSD) on rehabilitation after severe traumatic brain injury (TBI). Ninety-six patients with severe TBI patients were assessed 6 months after hospital discharge with the Posttraumatic Stress Disorder Interview, the Functional Assessment Measure (FAM), the Community Integration Questionnaire (CIQ), the Overt Aggression Scale (OAS), the General Health Questionnaire (GHQ), the Beck Depression Inventory (BDI), and the Satisfaction with Life Scale (SWL). PTSD was diagnosed in 27% of patients. Patients with PTSD reported higher scores on the GHQ and BDI, and lower scores on the FAM, CIQ, OAS, and SWLS than those without PTSD. Effective rehabilitation after severe TBI may be enhanced by management of PTSD.

Adaptation, Psychological↗

PubMed2001

Hypnotizability in acute stress disorder.

OBJECTIVE: This study investigated the relationship between acute dissociative reactions to trauma and hypnotizability. METHOD: Acutely traumatized patients (N=61) with acute stress disorder, subclinical acute stress disorder (no dissociative symptoms), and no acute stress disorder were administered the Stanford Hypnotic Clinical Scale within 4 weeks of their trauma. RESULTS: Although patients with acute stress disorder and patients with subclinical acute stress disorder displayed comparable levels of nondissociative psychopathology, acute stress disorder patients had higher levels of hypnotizability and were more likely to display reversible posthypnotic amnesia than both patients with subclinical acute stress disorder and patients with no acute stress disorder. CONCLUSIONS: The findings may be interpreted in light of a diathesis-stress process mediating trauma-related dissociation. People who develop acute stress disorder in response to traumatic experience may have a stronger ability to experience dissociative phenomena than people who develop subclinical acute stress disorder or no acute stress disorder.

Acute Disease↗

PubMed2001

Utilizing a systems approach to implement pressure ulcer prediction and prevention.

Efficient, effective patient care is an objective shared by all healthcare settings and systems. It is generally accepted that using national clinical guidelines facilitates pursuit of this objective. However, implementation of a guideline, or any process improvement activity, requires a systematic, collaborative approach from which new processes can be purposefully designed. This article reviews systems theory, presents the steps for process improvement using the Plan/Do/Check/Act cycle, and references a recent statewide quality improvement study conducted by the authors in collaboration with Stratis Health, a Minnesota Medical Peer Review Organization.

Beds↗

PubMed2001

Examining threats to skin integrity.

Intact skin serves a vital role in maintaining homeostasis of the body and is regarded as the body's first line of defense against invading micro-organisms. The skin's barrier function can be jeopardized or threatened by several events: aging, dryness, bathing technique, activities of daily living, and soaps. In this paper, the authors review the structures of the skin that facilitate moisture retention and examine bathing practices that threaten the integrity of the skin. Finally, wound and skin care nurses, as well as generalist nurses, are encouraged to critically review the type of soap and the techniques used for bathing.

Aging↗

PubMed2000

Role for cathepsin F in invariant chain processing and major histocompatibility complex class II peptide loading by macrophages.

The major histocompatibility complex (MHC) class II-associated invariant chain (Ii) regulates intracellular trafficking and peptide loading of MHC class II molecules. Such loading occurs after endosomal degradation of the invariant chain to a approximately 3-kD peptide termed CLIP (class II-associated invariant chain peptide). Cathepsins L and S have both been implicated in degradation of Ii to CLIP in thymus and peripheral lymphoid organs, respectively. However, macrophages from mice deficient in both cathepsins S and L can process Ii and load peptides onto MHC class II dimers normally. Both processes are blocked by a cysteine protease inhibitor, indicating the involvement of an additional Ii-processing enzyme(s). Comparison of cysteine proteases expressed by macrophages with those found in splenocytes and dendritic cells revealed two enzymes expressed exclusively in macrophages, cathepsins Z and F. Recombinant cathepsin Z did not generate CLIP from Ii-MHC class II complexes, whereas cathepsin F was as efficient as cathepsin S in CLIP generation. Inhibition of cathepsin F activity and MHC class II peptide loading by macrophages exhibited similar specificity and activity profiles. These experiments show that cathepsin F, in a subset of antigen presenting cells (APCs), can efficiently degrade Ii. Different APCs can thus use distinct proteases to mediate MHC class II maturation and peptide loading.

Animals↗

PubMed2000

Secreted cathepsin L generates endostatin from collagen XVIII.

Endostatin, an inhibitor of angiogenesis and tumor growth, was identified originally in conditioned media of murine hemangioendothelioma (EOMA) cells. N-terminal amino acid sequencing demonstrated that it corresponds to a fragment of basement membrane collagen XVIII. Here we report that cathepsin L is secreted by EOMA cells and is responsible for the generation of endostatin with the predicted N-terminus, while metalloproteases produce larger fragments in a parallel processing pathway. Efficient endostatin generation requires a moderately acidic pH similar to the pericellular milieu of tumors. The secretion of cathepsin L by a tumor cell line of endothelial origin suggests that this cathepsin may play a role in angiogenesis. We propose that cleavage within collagen XVIII's protease-sensitive region evolved to regulate excessive proteolysis in conditions of induced angiogenesis.

Animals↗

PubMed2000

The generality of cognitive bias in acute stress disorder.

Cognitive bias was investigated in acutely traumatised civilians with either acute stress disorder (ASD; n = 26) or no ASD (n = 24). Participants completed the Acute Stress Disorder Interview, the Beck Depression Inventory, the Beck Anxiety Inventory (BAI), the Impact of Event Scale (IES), and an Event Probability Questionnaire and an Event Cost Questionnaire that comprised items pertaining to (a) external harm, (b) somatic sensations and (c) social events. ASD participants exaggerated both the probability of negative external harm, somatic and social events occurring, and the adverse cost of those events more than non-ASD participants. Elevated probability and cost estimates were predicted by BAI and IES-Avoidance scores, respectively. These findings are discussed in the context of different patterns observed in other anxiety disorders, and interpreted in terms of network theories of posttraumatic stress.

Accidents, Traffic↗

PubMed2000

Autobiographical memory in diabetes mellitus patients.

OBJECTIVE: Although current theorizing proposes that adjustment to insulin-dependent diabetes mellitus (IDDM) is influenced by appraisals of past health, there is little research into the role of autobiographical recall in patients with this condition. Autobiographical memory patterns were investigated in patients with IDDM and controls. METHOD: Fifteen patients with IDDM and 15 control participants were administered the Autobiographical Memory Test, the Beck Depression Inventory (BDI), and the Multidimensional Health Locus of Control Survey (MHLCS). RESULTS: Patients with IDDM displayed impaired access to specific positive memories and took longer to retrieve memories than controls. Impaired retrieval in patients with IDDM was associated with higher scores on the MHLCS-Powerful Others scale. CONCLUSIONS: Findings suggest that impaired recall of positive experiences is associated with poor adjustment to IDDM.

Adaptation, Psychological↗

PubMed2000

Telephone crisis intervention skills: a simulated caller paradigm.

Counseling skills were evaluated in a telephone counseling service for Vietnam veterans. Thirty simulated crisis calls were made to telephone counselors by experienced clinical psychologists. The counselors' responses were rated on dimensions that indexed general counseling skills, knowledge of veteran needs, and provision of appropriate advice. Whereas the majority of callers demonstrated adequate counseling skills, many lacked knowledge of veterans' posttraumatic stress, common veteran terminology, and the nature of veterans' experiences. The findings suggest that telephone counseling services that target specific populations should employ comprehensive training to ensure that counselors possess adequate and relevant knowledge about callers and their presenting problems. The simulated caller paradigm appears to be an effective paradigm for training and evaluation of telephone counselors.

Counseling↗

PubMed2000

Specific autobiographical memory following hypnotically induced mood state.

This study investigated the impact of hypnotically induced mood on the specificity of autobiographical memory. High (n = 24) and low (n = 21) hypnotizable participants were administered a hypnotic induction for sad, neutral, or happy mood and were asked to retrieve specific autobiographical memories in response to positive and negative cue words. Whereas high hypnotizable participants in the sad condition provided fewer specific memories in response to positive rather than negative cues, those in the neutral and happy conditions responded similarly to positive and negative cues. Findings suggest that impaired recall of specific memories may be mediated by state factors associated with sad mood. These results point to the utility of hypnotic mood induction as a means to experimentally investigate the relationship between mood and autobiographical memory.

Adult↗