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Research findings have suggested that social support decreases cardiovascular reactivity and reduces the incidence of cardiovascular disease. The authors describe 2 studies evaluating the association between social support and cardiovascular reactivity to a stressor. In both studies, it was predicted that the presence of a supportive person would exert a buffering effect on cardiovascular reactivity. In Study 1, 68 participants were randomly assigned to 1 of 3 conditions: alone, supportive, and nonsupportive. In Study 2, 60 participants were randomly assigned to 1 of 3 conditions: highly supportive, supportive, and nonsupportive. In both studies, a speech was the stressor. Results in both studies showed no significant differences in cardiovascular reactivity between supportive and nonsupportive conditions. The results failed to support the reactivity buffering effects of social support. Findings are explained in terms of evaluation apprehension theory, familiarity of support provider, and level of social support.

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Factor analytic studies of trauma victims' posttraumatic stress disorder (PTSD) have offered conflicting hypotheses about how to conceptualize PTSD into symptom categories. The present study used confirmatory factor analyses of self-reported PTSD symptomatology from 5,664 child and adolescent victims of Hurricane Hugo to compare 10 models of PTSD dimensionality. PTSD was best represented by a 2nd-order PTSD factor that manifests in 3 symptom clusters (Intrusion/Active Avoidance, Numbing/Passive Avoidance, and Arousal). This model was cross-validated on 3 age groups (late childhood, early adolescence, and late adolescence), and results indicated factorial invariance across groups. PTSD symptoms varied in relative centrality to the underlying dimensions of PTSD, which differed in their relations with anxiety and degree of traumatic exposure. Implications for classification criteria and an empirically supported theory of PTSD are discussed.

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Examined 5 conditional probability indices to determine the diagnostic efficacy of 48 symptoms associated with posttraumatic stress disorder (PTSD) in 5,687 children exposed to Hurricane Hugo, of whom 5.5% had a diagnosis of posttraumatic stress syndrome (PTSS). Moderate levels of sensitivity and high levels of specificity were obtained for most symptoms. Odds ratios more precisely demonstrated that some Diagnostic and Statistical Manual of Mental Disorders (DSM) symptoms of PTSD, especially when combined, were useful for identifying children with PTSS but that anxiety symptoms and some DSM symptoms of PTSD had poor diagnostic utility. Satisfying criteria for the DSM-III-R numbing/avoidance cluster and symptoms from the numbing/avoidance cluster had the highest diagnostic efficacy, suggesting that avoidance may be the hallmark of severe posttraumatic reactions. These results suggest which symptoms should be conceptualized as central versus peripheral to the disorder and which symptoms and symptom combinations clinicians should attend to most when diagnosing or screening PTSD in children.

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A meta-analysis was performed to systematically assess the effect of cognitive-behavioral treatments for bulimia. To protect against past criticisms of meta-analyses, this study focused on well-defined hypotheses with clearly articulated conceptual foundations. Twenty-six studies of the cognitive-behavioral treatment of bulimia were selected through computer searches. Effect sizes were calculated for changes in behavioral outcome measures (25 independent hypothesis tests) and cognitive-attitudinal outcome measures (17 independent hypothesis tests). Additionally, two effect sizes were generated for within and between group comparisons. The analysis revealed an effect size of average r = 0.69 for behavioral outcome measures (average r = 0.64 for between group and average r = 0.74 for within group) and average r = 0.67 for cognitive-attitudinal outcome measures (average r = 0.64 for between group and average r = 0.69 for within group). Follow-up effect sizes were less favorable; however, the diversity of time spans and outcome measures used to calculate follow-up effect sizes limit their utility. Overall, results suggest that the use of a cognitive-behavioral therapy will result in favorable treatment outcomes and implications for future research are discussed.

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The present study was designed to explore mechanisms of amnesia for meaningful auditory material presented during the sleep onset transition. Thirty undergraduate subjects (17 female, 13 male) were presented with auditory stimuli in an oddball paradigm until sleep onset. Subjects were allowed to accumulate either 30 seconds or 10 minutes of sleep, then awakened and tested on free recall and recognition memory for the meaningful stimuli. After 10 minutes of sleep, but not after 30 seconds of sleep, subjects had profound amnesia on free recall for stimuli presented in the 4-minute window prior to sleep onset. Increased beta electroencephalograph (EEG) power during the sleep period correlated positively with recall of stimuli in the 4-minute presleep window. Event-related potential recordings provided suggestive evidence that subjects continued to process the auditory stimuli to some extent during the sleep onset transition. When allowed to sleep for 10 minutes, subjects evidenced a mixed anterograde and retrograde amnesia for auditory stimuli presented in the 4-minute window prior to sleep onset. The results are discussed in terms of stimulus encoding, consolidation, and retrieval.

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Subjective sleep complaints and food intolerances, especially to milk products, are frequent symptoms of individuals who also report intolerance for low-level odors of various environmental chemicals. The purpose of the present study was to evaluate the objective nature of nocturnal sleep patterns during different diets, using polysomnography in community older adults with self-reported illness from chemical odors. Those high in chemical odor intolerance (n = 15) exhibited significantly lower sleep efficiency (p = .005) and lower rapid-eye-movement (REM) sleep percent (p = .04), with a trend toward longer latency to REM sleep (p = .07), than did those low in chemical intolerance (n = 15), especially on dairy-containing as compared with nondairy (soy) diets. The arousal pattern of the chemical odor intolerant group differed from the polysomnographic features of major depression, classical organophosphate toxicity, and subjective insomnia without objective findings. The findings suggest that community elderly with moderate chemical odor intolerance and minimal sleep complaints exhibit objectively poorer sleep than do their normal peers. Individual differences in underlying brain function may help generate these observations. The data support the need for similar studies in clinical populations with chemical odor intolerance, such as multiple chemical sensitivity patients and perhaps certain veterans with "Persian Gulf Syndrome."

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Three patients underwent cranial irradiation as part of treatment for childhood malignancy. Two of these patients had acute lymphocytic leukemia and one had an astrocytoma. All had longlasting remissions from their childhood malignancy but 8-15 years later developed a basal cell carcinoma of the scalp within previous radiation portals. The basal cell carcinomas were all treated successfully using Mohs micrographic surgery. Follow-up of patients receiving irradiation for childhood malignancy should include periodic cutaneous examinations of previously irradiated sites.

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A variety of bioactive compounds have now been introduced into plants through recombinant DNA techniques. Early examples included genes encoding proteins conferring herbicide tolerance and insect or virus resistance. More recently, pharmacologically useful compounds such as enkephalin and immunoglobulin have been produced in transgenic plants. Modification of existing compounds to provide better nutritional value or improved functional properties is exemplified in the case of seed storage proteins. The value of RNAs as bioactive compounds for suppression of undesirable products and viral infection has now been demonstrated in plants. The developmentally regulated expression of novel bioactive compounds in defined tissues, and their targeting to specific subcellular locations, is becoming of ever increasing economic and sociological importance as knowledge of the molecular mechanisms involved accumulates.

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Daucus carota L., callus was cultured on various levels of the folate analogs, methotrexate (4-amino-10-methylfolic acid, amethopterin) and aminopter in (4-aminofolic acid). Callus growth was inhibited as analog concentrations were increased from 0.01 µM to 10 µM. Methotrexate concentrations in excess of 10 µM were lethal. In contrast, concentrations of aminopterin in the range of 10 to 100 µM resulted in renewed growth and somatic embryogenesis leading to plant regeneration. This plant regeneration occurred even in the presence of 5.0 mg/l 2,4-D or NAA (concentrations up to fifty times higher than that required to maintain callus growth). These observations reveal that aminopterin at high concentrations, but not methotrexate, triggers somatic embryogenesis in the presence of auxin. All tested levels of aminopterin permitted regeneration in the absence of auxin.

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