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At least 217 records · Page 12Linked to original sources
PubMed2001

Worry propensity and the perception of risk.

This paper examines how the tendency to worry impacts risk estimation for an upcoming, stressful event. Students in a statistics class completed worry, anxiety, and subjective risk questionnaires on the first day of class. State-anxiety and subjective risk questionnaires were again administered immediately before their first examination. Subjects showed significant increases in anxiety and the perceived risk of poor academic performance in the class. Risk domains unrelated to the examination (e.g., physical threats) remained stable across measurement periods. Regression analysis was used to determine the independent contribution of worry propensity in predicting elevations in the perceived risk of poor academic performance. The analysis showed that worry propensity predicted subjective risk bias, even after variance attributable to current mood and trait anxiety had been removed. Results from a second series of regression equations suggested subjective risk biases partially mediated the relationship between worry propensity and current mood. These results are used to argue that the elevations in state anxiety observed when worriers are confronted with a stressful event are largely a function of risk inflation.

Achievement↗
PubMed1999

Interpretive biases for ambiguous stimuli in social anxiety.

A growing body of literature suggests that individuals with high levels of general anxiety form threatening interpretations of ambiguous events. Although theoretical formulations of pathological social anxiety emphasize the importance of a negative interpretive-style in the etiology and maintenance of the disorder, we are unaware of any study that documents this presumed phenomenon. To address this issue, we assessed for possible interpretive biases in a group of high and low socially-anxious students. The results indicated that socially-anxious subjects showed more threatening interpretations of ambiguous, interpersonal events when compared to the low-anxious participants. However, this bias was marked not so much by an outright negative interpretation style, but rather by a failure of the socially-anxious subjects to show a positive interpretation as was evinced by the low-anxious individuals. These group differences in interpretive style appeared to be influenced by trait aspects of social anxiety rather than differences in current mood state. No group differences emerged in interpretations of events that involved non-personal stimuli suggesting there is content specificity in the interpretive biases associated with social-anxiety.

Adult↗
PubMed1999

Endothelial dysfunction during acute methionine load in hyperhomocysteinaemic patients.

Hyperhomocysteinaemia has been associated with arterial and venous thrombosis possibly by causing damage to the endothelium. We hypothesised that an oral load in methionine, that increases plasma homocysteine, would also result in an increase in biological markers of endothelial or platelet dysfunction. Then we investigated two groups of patients with arterial or venous occlusive disease: 17 with hyperhomocysteinemia and 12 without hyperhomocysteinemia. We measured in both groups plasma soluble thrombomodulin, von Willebrand factor, P-selectin and tissue factor plasma inhibitor before and 6 hours after a load with 100 mg/kg oral methionine. Methionine load resulted in a significant increase in von Willebrand factor in both groups (P<0.02), suggesting that endothelial dysfunction occurs during the load.

Administration, Oral↗
PubMed1999

Attentional reactions to an MI: the impact of mood state, worry, and coping style.

This study investigated the possible development of an attentional bias to cardiac-related words in subjects who recently experienced a myocardial infarction (MI). It was hypothesized that cardiac-related stimuli would have attention-capturing characteristics for post-MI subjects, and this bias would be moderated by level of anxiety, degree of cardiac-related worry, and the subject's coping style. Post-MI subjects (n = 33) and matched controls (n = 31) participated in an attentional search task. The post-MI subjects failed to show the predicted group increases in attention allocated to cardiac stimuli, but a difference between groups still occurred as the control group exhibited directed inattention to cardiac stimuli. Subsequent analysis indicated those post-MI subjects who did evince an attentional bias toward cardiac stimuli had higher monitoring scores on a self-report measure of coping style. Level of emotional distress and cardiac-related worry failed to predict attentional bias for the post-MI subjects.

Adaptation, Psychological↗
PubMed1981

Surgical features of cranial metastases.

This study comprises 14 patients with metastatic involvement of the cranium treated between 1957 and 1979. Anatomical and radiological aspects and the clinical manifestations of these metastatic lesions are analyzed. These lesions are not a definite clinical entity, and they have specific therapeutic problems. Treatment consisted of surgical excision and radiotherapy. The surgical results are presented and discussed.

Adolescent↗
PubMed2005

[Quantitative relationships between ADC and perfusion changes in acute ischemic stroke using combined diffusion-weighted imaging and perfusion MR (DWI/PMR)].

UNLABELLED: MR-based diffusion- and perfusion-weighted imaging (DWI/PWI) has become the standard imaging technique to assess the individual brain pathophysiological status in acute ischemic stroke. The finding of a "mismatch" with larger PWI than DWI abnormality is thought to reflect the presence of tissue at-risk of infarction, i.e., penumbra. However, there has been no detailed study of the quantitative relationships between perfusion and diffusion changes in stroke patients. According to the experimental concept of penumbra, the ADC would be expected to remain unchanged despite decreasing perfusion until a critical threshold is reached. We have tested this hypothesis directly in man. METHODS: DWI/PWI was performed in 7 patients with MCA territory stroke within 4-10 hrs from onset. Mismatch was defined on diffusion and rMTT maps, and circular ROIs were positioned within the ADC lesion (D), the mismatch area (M), and the normal appearing cortex (N); mirror ROIs were also obtained, and affected/unaffected ratios for ADC and rCBF were computed for each ROI. RESULTS: The mean (+/-1 SD) ADC ratios were 0.60 +/- 0.09, 0.95 +/- 0.10 and 1.02 +/- 0.04 in L, M and N, respectively; the corresponding rCBF ratios were 0.32 +/- 0.12, 0.75 +/- 0.14 and 0.97 +/- 0.09, respectively. The relationship was non-linear, with the rCBF but not the ADC ratio for M being significantly lower (p < 0.01) than that for N. A threshold for decline in ADC was apparent around 0.50 rCBF ratio. COMMENT: These results directly document in man that the ADC declines only after hypoperfusion has reached a certain degree (about 50%), consistent with the concept of the ischaemic penumbra.

Acute Disease↗
PubMed2001

Impact of threat relevance on P3 event-related potentials in combat-related post-traumatic stress disorder.

The purpose of this study was to examine electrophysiological response to trauma-relevant stimuli in combat-related post-traumatic stress disorder (PTSD). Study design incorporated comparison of 10 Vietnam War veterans with PTSD diagnosis to 10 Vietnam War veterans with no mental disorder diagnosis on P3 components in a series of two oddball tasks (trauma-relevant threat, trauma-irrelevant threat) counterbalanced for order. Each task included high probability emotionally neutral distractor words and low probability neutral target words, but differed in the content of low probability threat words. Whereas threat words in the trauma-relevant oddball task pertained directly to combat trauma, threat words in the trauma-irrelevant oddball task were socially threatening words. Results revealed that, in comparison to healthy combat veterans, those diagnosed with PTSD demonstrated: (a) attenuated P3 response to neutral target items at selected electrode sites across both oddball tasks; and (b) increased responsivity to trauma-relevant combat stimuli but not to trauma-irrelevant social-threat stimuli at frontal electrode sites (F3, F4). Results are consistent with resource allocation models of PTSD, which suggest that PTSD is characterized by attentional bias to threat stimuli at the expense of attention to emotionally neutral information.

Affect↗
PubMed2001

Molecular chaperones involved in chloroplast protein import.

Transport of cytoplasmically synthesized precursor proteins into chloroplasts, like the protein transport systems of mitochondria and the endoplasmic reticulum, appears to require the action of molecular chaperones. These molecules are likely to be the sites of the ATP hydrolysis required for precursor proteins to bind to and be translocated across the two membranes of the chloroplast envelope. Over the past decade, several different chaperones have been identified, based mainly on their association with precursor proteins and/or components of the chloroplast import complex, as putative factors mediating chloroplast protein import. These factors include cytoplasmic, chloroplast envelope-associated and stromal members of the Hsp70 family of chaperones, as well as stromal Hsp100 and Hsp60 chaperones and a cytoplasmic 14-3-3 protein. While many of the findings regarding the action of chaperones during chloroplast protein import parallel those seen for mitochondrial and endoplasmic reticulum protein transport, the chloroplast import system also has unique aspects, including its hypothesized use of an Hsp100 chaperone to drive translocation into the organelle interior. Many questions concerning the specific functions of chaperones during protein import into chloroplasts still remain that future studies, both biochemical and genetic, will need to address.

Chloroplast Proteins↗