A comparative cell-based high throughput screening strategy for the discovery of selective tyrosine kinase inhibitors with anticancer activity

Growth factor receptor tyrosine kinases (RTK) have been implicated in tumor growth, metastasis and angiogenesis, and are thus considered promising targets for therapeutic intervention in malignant diseases. We present a novel drug discovery strategy to find inhibitors of RTKs based on comparative screening of compound libraries employing functional cellular assays. Cell lines stably expressing HER2 and the receptors for hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), insulin-like growth factor-I (IGF-I) and epidermal growth factor (EGF) have been established. All cell lines are based on FDC-P1, a murine myeloid progenitor cell line which allows a direct comparison of results obtained in primary screens. In addition, the same cell lines are suitable for compound optimization and for animal studies. Using this strategy we report the identification of promising lead candidates for further drug development which are highly selective, non-cytotoxic and cell permeable with potencies in the low micromolar range.

Cues, frequency, and the disturbing nature of intrusive thoughts: patterns seen in rescue workers after the crash of Flight 427

Intrusive thoughts have been identified as key elements of chronic or traumatic stress, but many questions remain about how they operate and what causes persistence of disturbing intrusions. The present study considers these questions, examining the impact of having intrusive thoughts that are cued by stimuli in one's environment as opposed to uncued intrusions that seem to "come out of the blue." In addition, this research evaluates the extent to which distress accompanying intrusive thoughts shortly after a traumatic event predicts persistence of intrusions over time. Rescue workers who responded to the crash of Flight 427 were studied 4 to 8 weeks, and 6, 9, and 12 months after the disaster. Participants who reported crash-related thoughts that were not prompted by cues showed higher levels of distress than those reporting only cued thoughts or those reporting neither. The magnitude of distress that these thoughts caused in the first 2 months after the crash was important in predicting subsequent frequency of unwanted thoughts. The presence or absence of cues and their role in the maintenance of distress also is discussed.

Acute and chronic posttraumatic stress disorder in motor vehicle accident victims

OBJECTIVE

This study reports the rates of acute and chronic posttraumatic stress disorder (PTSD) in a suburban community study group of 122 victims of serious motor vehicle accidents and a comparison group of 42 (who had been involved in minor, non-motor-vehicle accidents) followed over 12 months.

METHOD

Motor vehicle accident victims were systematically recruited and examined with comparison subjects at 1, 3, 6, 9, and 12 months after the accident. The authors used the Structured Clinical Interview for DSM-III-R to assess DSM-III-R axis I disorders including PTSD.

RESULTS

One month after the accident, 34.4% of the motor vehicle accident victims met criteria for PTSD (versus 2.4% of the comparison subjects). Similarly, at 3 and 6 months, rates of PTSD were higher (25.2% and 18.2%) in the motor vehicle accident victims than in the comparison group. Female victims were 4.64 times more likely than male victims to have PTSD at 1 month. Victims with a history of PTSD were 8.02 times more likely at 1 month and 6.81 times more likely at 3 months to have PTSD than those without a history of PTSD. Having an axis II disorder increased the risk for PTSD at 6 months. After adjustment for a history of PTSD and potentially confounding variables, women were 4.39 times more likely than men to develop PTSD at 1 month but did not have a higher risk for chronic PTSD; at 6 months, those with an axis II disorder were at greater risk of PTSD.

CONCLUSIONS

Rates of PTSD are high in victims of serious motor vehicle accidents and remain high 9 months later. Female victims have an increased risk of acute but not chronic PTSD. Individuals with a history of PTSD are at risk of acute and chronic PTSD. An axis II disorder increases the risk for chronic but not acute PTSD.

Health psychology: mapping biobehavioral contributions to health and illness

Our evolving understanding of how psychosocial and behavioral factors affect health and disease processes has been marked by investigation of specific relationships and mechanisms underlying them. Stress and other emotional responses are components of complex interactions of genetic, physiological, behavioral, and environmental factors that affect the body's ability to remain or become healthy or to resist or overcome disease. Regulated by nervous, endocrine, and immune systems, and exerting powerful influence on other bodily systems and key health-relevant behaviors, stress and emotion appear to have important implications for the initiation or progression of cancer, HIV, cardiovascular disease, and other illnesses. Health-enhancing and health-impairing behaviors, including diet, exercise, tobacco use, and protection from the sun, can compromise or benefit health and are directed by a number of influences as well. Finally, health behaviors related to being ill or trying to avoid disease or its severest consequences are important. Seeking care and adhering to medical regimens and recommendations for disease surveillance allow for earlier identification of health threats and more effective treatment. Evidence that biobehavioral factors are linked to health in integrated, complex ways continues to mount, and knowledge of these influences has implications for medical outcomes and health care practice.

Assessment of characteristics of intrusive thoughts and their impact on distress among victims of traumatic events

OBJECTIVE

This study examines the psychometric properties of the Intrusive Thoughts Questionnaire (ITQ) and its utility as a predictor of distress among trauma victims.

METHOD

Victims of three types of trauma, a motor vehicle accident (N = 115), a hurricane (N = 182), and recovery work after an airline disaster (N = 159), completed the ITQ along with the Impact of Event Scale (IES) and the Symptom Checklist-90, Revised (SCL-90-R), at several different time points after their exposure.

RESULTS

The ITQ was a reliable and valid instrument that was positively related to concurrent measures of distress as well as a predictor of long-term stress responding. Characteristics of intrusive thoughts reflecting the extent to which they were unwanted or controllable, were identified as key determinants of distress.

CONCLUSIONS

The ITQ is a useful adjunct to current measures of intrusions, allowing for greater specificity in analyses of responses to trauma. Evaluation of characteristics of intrusions indicated that frequency of intrusions was neither the only predictor of distress nor the best predictor of trauma-related outcomes.

Responses of natural killer cell activity to acute laboratory stressors in healthy men at different times of day

To assess possible diurnal variations in natural killer reactivity to acute laboratory stressors, this study investigated changes in natural killer cell activity (NKCA) during and after three stressors (mental arithmetic, speech, and the Stroop) at 3 times of the day (08:00, 12:00, and 16:00) in 30 healthy men. NKCA activity increased during mental arithmetic and speech tasks at all 3 times of the day. Change in NKCA was greatest in the afternoon. Differences in the magnitude of mood changes were also observed at the 3 times of day, parallel to immune reactivity. These findings suggest that the dynamics of stress-related NKCA are more complex than previously believed and that time of day may affect the way they are generated or interpreted.

Responses of natural killer cell activity to acute laboratory stressors in healthy men at different times of day

To assess possible diurnal variations in natural killer reactivity to acute laboratory stressors, this study investigated changes in natural killer cell activity (NKCA) during and after three stressors (mental arithmetic, speech, and the Stroop) at 3 times of the day (08:00, 12:00, and 16:00) in 30 healthy men. NKCA activity increased during mental arithmetic and speech tasks at all 3 times of the day. Change in NKCA was greatest in the afternoon. Differences in the magnitude of mood changes were also observed at the 3 times of day, parallel to immune reactivity. These findings suggest that the dynamics of stress-related NKCA are more complex than previously believed and that time of day may affect the way they are generated or interpreted.

Successful behavioral interventions to prevent cancer: the example of skin cancer

Important behavioral sources of risk for cancer have been identified and programs to reduce this risk have been initiated. The most heavily studied behavioral risk is tobacco use, but considerable attention has also gone to prevention of skin cancer by modifying sun exposure. Research has shown a strong link between sun exposure and skin cancer, and opportunities to prevent this cancer by changing behavior should be effective. Unlike unmodifiable sources of risk, sun exposure should be modifiable through behavioral intervention. This review considers research in this expanding area, concentrating on predictors of sun protective behaviors, modification of sun exposure, and surveillance for early signs of cancer. The elements of behavior change programs that contribute to successful intervention as well as barriers to successful behavior change and future directions for this effort are considered.

Sleep as a mediator of the stress-immune relationship

OBJECTIVE

To evaluate the role of sleep in the relationship of intrusive thoughts/avoidance behaviors to natural killer cell (NKC) number and function.

METHOD

Twenty-nine individuals seeking treatment for bereavement-related depression were studied in the sleep laboratory. Background and clinical variables, including the Impact of Event Scale (IES) and the Hamilton Rating Scale for Depression (HRSD), were administered during the week preceding a 3-night sleep study. Blood samples were collected upon awakening after the second or third night of sleep.

RESULTS

Greater frequency of intrusive thoughts and avoidance behaviors was associated with more time spent awake during the first non-rapid eye movement period (NREM-1) and lower NKC number (p values < .01). Greater time spent awake during NREM-1 was associated with lower NKC numbers (p < .05). Regression analyses revealed that the significant relationship between symptoms of intrusion/avoidance and NKC number was no longer significant when time spent awake during NREM-1 was entered into the regression equation. Time spent awake during NREM-1 accounted for 12% of the variance in NKC number (p < .05), whereas intrusion/avoidance accounted for 7% of the variance in NKC number (NS).

CONCLUSIONS

These results suggest that EEG-assessed sleep may be a significant correlate of the stress-immune relationship.

Measurement of perceived disruption during rebuilding following Hurricane Andrew

The purpose of this study was to develop and evaluate a measure of perceived disruption during rebuilding following a disaster. Two eight-item scales, which measured intensity of disruption during the entire repair phase (Intensity-RP) and intensity of disruption during the past month (Intensity-PM) were developed and administered to 135 survivors of Hurricane Andrew. At 9 to 12 months postdisaster, Intensity-RP and Intensity-PM were both significantly associated with scores on the Global Severity Index of the SCL-90-R, and with scores on the Impact of Event-Intrusion Scale; Intensity-PM alone was significantly associated with PTSD scores. Regression analyses indicated that each scale contributed significant unique variance in predicting mental health symptoms, even after controlling for relevant demographic and initial disaster exposure variables.

Acute and chronic distress and posttraumatic stress disorder as a function of responsibility for serious motor vehicle accidents

In this study on the effects of attributions of responsibility for traumatic events, stress, coping, and symptoms of posttraumatic stress disorder (PTSD) were measured, including intrusive thoughts among 130 victims of serious motor vehicle accidents (MVAs) 14-21 days and 3, 6, and 12 months after their accident. MVA victims and 43 control participants were categorized by accident and attribution of responsibility for their accidents (self-responsible, other-responsible, and control). Although initially all MVA victims reported higher levels of intrusive thoughts and were more likely to meet criteria for PTSD diagnoses, only other-responsible participants continued to demonstrate increased distress 6 and 12 months postaccident. Self-responsible participants used more self-blame coping than other-responsible participants, although within the self-responsible group, use of self-blame was associated with more distress.

Chronic stress and natural killer cell activity after exposure to traumatic death

OBJECTIVE

The present study examined the effects of working at the crash site of USAir Flight 427 on psychological, cardiovascular, and immunological sequelae of stress within 2 months of the recovery work and again 6 months after the crash.

METHOD

A total of 159 workers at the crash site and 41 controls were examined within 2 months of the crash and again 6 months after the crash. Subjects were initially grouped according to whether they had contact with human remains. For a finer-grained analysis of exposure to bodies, subjects were also grouped by degree of exposure, determined by the area in which the workers were stationed. Dependent measures included intrusive thoughts, coping styles, and symptom reporting, as well as heart rate and blood pressure, and NK cell number and activity.

RESULTS

Workers exposed to body parts at the actual crash site, and those who were exposed to remains without expecting to be, exhibited more symptoms of stress than workers who saw bodies and body parts at the morgue and those who did not see human remains. Non-morgue workers who were exposed to bodies or body parts had the highest levels of intrusive thoughts at both time points, and the highest NK cell activity at Time 1. NK activity in this group decreased to levels comparable with other groups at Time 2.

CONCLUSIONS

Increased NK activity is unusual in chronic stress situations, and may be because of acute stress experienced as a result of being asked to talk and think about the crash. The finding that the more one was exposed to human remains the less distress he or she reported is discussed in terms of adaptation, expectancy, and control.

Acute and chronic distress and posttraumatic stress disorder as a function of responsibility for serious motor vehicle accidents

In this study on the effects of attributions of responsibility for traumatic events, stress, coping, and symptoms of posttraumatic stress disorder (PTSD) were measured, including intrusive thoughts among 130 victims of serious motor vehicle accidents (MVAs) 14-21 days and 3, 6, and 12 months after their accident. MVA victims and 43 control participants were categorized by accident and attribution of responsibility for their accidents (self-responsible, other-responsible, and control). Although initially all MVA victims reported higher levels of intrusive thoughts and were more likely to meet criteria for PTSD diagnoses, only other-responsible participants continued to demonstrate increased distress 6 and 12 months postaccident. Self-responsible participants used more self-blame coping than other-responsible participants, although within the self-responsible group, use of self-blame was associated with more distress.

Coping self-efficacy buffers psychological and physiological disturbances in HIV-infected men following a natural disaster

The importance of coping self-efficacy (CSE) appraisals on psychological and physiological functioning for HIV seropositive patients facing a severe environmental stressor was tested comparing 37 HIV-infected gay men and 42 healthy male control participants following Hurricane Andrew. Results suggested that greater levels of CSE were related to lower emotional distress and posttraumatic stress disorder (PTSD) symptoms in both groups. In addition, greater CSE was associated with lower norepinephrine to cortisol ratios in the HIV group but not in the healthy control group. Results are discussed in relation to the coping process for HIV-infected individuals specifically and chronically ill populations in general who face severe environmental stressors.

Acquisition of a new-latency conditioned nictitating membrane response--major, but not complete, dependence on the ipsilateral cerebellum

Classical conditioning of the nictitating membrane response (NMR) of rabbits is simple associative learning of a motor response. In several two-stage experiments, reversible inactivations of the deep cerebellar nuclei in stage 1 appeared to prevent acquisition of NMR conditioning in naive rabbits--no conditioned responses (CRs) were evident after inactivations were lifted in stage 2. Results of a three-stage experiment were different. When subjects were first trained with a light conditional stimulus (CS) in stage 1, reversible cerebellar inactivations during conditioning to a different, tone CS during stage 2 did not appear to prevent new learning because CRs to the tone CS were evident when the inactivation was lifted. Results from the two-stage experiments support the suggestion that the cerebellum is essential for the acquisition of NMR conditioning, but results from the three-stage experiment do not. Here, we use a three-stage design with different interstimulus intervals (ISIs) in stages 1 and 2. Because CRs develop with latencies-to-peak dependent on the ISI, learning during stage 1 can be dissociated from that accruing in stage 2. Complete inactivation of the ipsilateral cerebellar nuclei with muscimol substantially but not completely prevented learning with the second ISI during stage 2 because small CR peaks around the stage 2 ISI could be detected in some subjects after the inactivation had been lifted in stage 3. We suggest that the weak levels of conditioning possible during unilateral inactivation depend on the contralateral cerebellum or on extracerebellar circuitry and that these may be capable of supporting transfer of conditioning in a previous three-stage experiment. But, we confirm that normal NMR conditioning is critically dependent on the ipsilateral cerebellum.

Posttraumatic stress symptoms, intrusive thoughts, loss, and immune function after Hurricane Andrew

OBJECTIVE

To examine the impact of and relationship between exposure to Hurricane Andrew, a severe stressor, posttraumatic stress symptoms and immune measures.

METHODS

Blood draws and questionnaires were taken from community volunteer subjects living in the damaged neighborhoods between 1 and 4 months after the Hurricane.

RESULTS

The sample exhibited high levels of posttraumatic stress symptoms by questionnaire (33% overall; 76% with at least one symptom cluster), and 44% scored in the high impact range on the Impact of Events (IES) scale. A substantial proportion of variance in posttraumatic stress symptoms could be accounted for by four hurricane experience variables (damage, loss, life threat, and injury), with perceived loss being the highest correlate. Of the five immune measures studied Natural Killer Cell Cytotoxicity (NKCC) was the only measure that was meaningfully related (negatively) to both damage and psychological variables (loss, intrusive thoughts, and posttraumatic stress disorder (PTSD). White blood cell counts (WBCs) were significantly positively related with the degree of loss and PTSD experienced. Both NKCC (lower) and WBC were significantly related to retrospective self-reported increase of somatic symptoms after the hurricane. Overall, the community sample was significantly lower in NKCC, CD4 and CD8 number, and higher in NK cell number compared to laboratory controls. Finally, evidence was found for new onset of sleep problems as a mediator of the posttraumatic symptom-NKCC relationship.

CONCLUSIONS

Several immune measures differed from controls after Hurricane Andrew. Negative (intrusive) thoughts and PTSD were related to lower NKCC. Loss was a key correlate of both posttraumatic symptoms and immune (NKCC, WBC) measures.

Stress and genetic testing for disease risk

Healthy people who believe they are at risk for a life-threatening disease appear to carry a substantial stress burden because of threat of disease and uncertainty of risk. Testing for risk factors may be helpful by reducing this uncertainty, but diseases with multiple causes, like breast cancer, appear to be determined by genetic factors and by age, reproductive behavior, exposure to environmental toxins, or unknown antecedents. For diseases caused by inherited genetic defects, testing brings different benefits and stressors. A model is proposed that predicts long-term distress when risk analysis suggests a very high risk, when uncertainty is not reduced, when results of testing are at odds with preventive actions already taken, and when people who receive a positive, risk-increasing result lack strong social support, coping skills, other psychosocial resources, or all of these.

Relation between beta-adrenergic receptor density and lymphocyte proliferation associated with acute stress

The relations between acute changes in beta-adrenoreceptor density on lymphocytes and lymphocyte proliferation to a laboratory speech stressor were examined. Male participants either prepared and delivered a challenging speech task or read from a list of words. Participants engaged in the speech task, but not those involved in reading, exhibited significant increases in systolic blood pressure (an index of sympathetic nervous system arousal) and beta-adrenoreceptor density, accompanied by significant decreases in lymphocyte proliferation to pokeweed mitogen (PWM) but not concanavalin A (Con A). Increases in adrenoreceptor density significantly predicted decreases in lymphocyte activity in response to both mitogens. The increases in beta-adrenoreceptor density in the speech task condition occurred within 5 min after the baseline period, when participants were preparing for the speech task, but not yet speaking. These findings suggest that an acute stressor eliciting sympathetic nervous system activity can evoke rapid changes in beta-adrenoreceptor activity and decreases in mitogenic responses.

Ventricular fibrillation in the patient with blunt trauma: not always exsanguination

Three cases of successful prehospital resuscitation of blunt trauma patients sustaining cardiac arrest resulting from ventricular fibrillation are reported. Although probably uncommon, ventricular fibrillation not caused by severe hypovolemia, exsanguination, or severe hypoxia in the setting of blunt trauma might be a treatable cause of cardiac arrest. Early electrocardiographic monitoring of patients with blunt trauma, including those with cardiac arrest, can detect this small, yet easily salvageable group of patients.

Self-reported stressors, symptom complaints and psychobiological functioning I: Cardiovascular stress reactivity

Taking into account neuroticism and lifestyle variables (smoking and alcohol consumption), cardiovascular and psychological reactions to stressful films were studied in four groups of subjects selected on self-reported levels of recent stressor load and symptom complaints (low-load/low-symptoms: low-load/high-symptoms; high-load/low-symptoms; high-load/high-symptoms). The films were known either to stimulate or to depress cardiovascular activity. The results showed that psychological reactions (distress; deactivation; openness/involvement) were associated with group membership and condition. In addition, high-symptom subjects were characterized by faster resting heart rates and smaller ECG T-wave amplitudes (TWAs), reflective of greater sympathetic tone on the myocard. Further, low-symptom subjects, in particular those labeled as stress-resistant (high-load/low-symptoms), exhibited larger myocardial responses to the cardiovascular-stimulating films than did high-symptom subjects. Low-symptom subjects showed predicted variations in physiological responses to the different films, whereas the responses by the high-symptom subjects showed lesser variation across films. It is concluded that the cardiovascular responses of low-symptom subjects more accurately followed the energetic demands of the body, whereas the high-symptom subjects were in a comparatively enduring state of arousal.

Time course of natural killer cell activity and lymphocyte proliferation in response to two acute stressors in healthy men

To clarify the time course of immune system activity during and after acute stressor exposure, this study collected immune measures from 31 men at 6 times (before, during, and after 2 common laboratory stressors; mental arithmetic with harassment or a cold pressor task). The 6-min stressor period was associated with increased self-report of pain and distress in both stressor groups and with increased systolic and diastolic blood pressure and heart rate in the mental arithmetic group. Increased natural killer cell activity in this group was observed during the task (2 and 5 min into the task) and 5 min after the task ended. A significant Group x Time effect was observed for lymphocyte proliferation to pokeweed mitogen, and a significant Group x Time x Dilution effect was observed for proliferation to concanavalin A. Inspection of the data suggested that this interaction was due to a reduction in proliferation in both stressor groups during the task period.

The relationship between stealing and eating disorders: a review

The literature exploring stealing behavior in individuals with an eating disorder is reviewed. Although epidemiological data are lacking, clinical observations and preliminary studies suggest an association between stealing behavior and eating disorders. Stealing appears to be strongly associated with bulimic symptoms in patients with eating disorders, and the presence of stealing behavior may serve as a marker of eating-disorder severity. The apparent connection between the two problems is discussed, and nine putative explanatory factors are examined: starvation-induced mental dysfunction, effects of medications, affective spectrum disorder, personality disorder, psychodynamic features, dissociative phenomena, tension reduction, pseudopubertal impulsivity, and sociocultural influences. Various combinations of these factors may operate in any particular patient. One of the challenges to our current understanding is the scarcity of information regarding the prevalence and distribution of stealing behavior in the general population. Areas for future research are suggested and include epidemiological surveys to investigate the proposed connection between stealing and eating disorders, examination of the effects of legal intervention, systematic study of the treatment of stealing in patients with eating disorders, and longitudinal studies exploring prognostic implications of stealing behavior.

Physical symptoms of chronic fatigue syndrome are exacerbated by the stress of Hurricane Andrew

This study examined the effects of Hurricane Andrew on physical symptoms and functional impairments in a sample of chronic fatigue syndrome (CFS) patients residing in South Florida. In the months after Hurricane Andrew (September 15-December 31, 1992), 49 CFS patients were assessed for psychosocial and physical functioning with questionnaires, interviews, and physical examinations. This sample was made up of 25 CFS patients living in Dade county, a high impact area, and 24 patients in Broward and Palm Beach counties, areas less affected by the hurricane. Based on our model for stress-related effects on CFS, we tested the hypothesis that the patients who had the greatest exposure to this natural disaster would show the greatest exacerbation in CFS symptoms and related impairments in activities of daily living (illness burden). In support of this hypothesis, we found that the Dade county patients showed significant increases in physician-rated clinical relapses and exacerbations in frequency of several categories of self-reported CFS physical symptoms as compared to the Broward/Palm Beach county patients. Illness burden, as measured on the Sickness Impact Profile, also showed a significant increase in the Dade county patients. Although extent of disruption due to the storm was a significant factor in predicting relapse, the patient's posthurricane distress response was the single strongest predictor of the likelihood and severity of relapse and functional impairment. Additionally, optimism and social support were significantly associated with lower illness burden after the hurricane, above and beyond storm-related disruption and distress responses. These findings provide information on the impact of environmental stressors and psychosocial factors in the exacerbation of CFS symptoms.

Lack of influence of diethylstilbestrol on induced pancreatic ductal carcinomas in Syrian hamsters

Syrian golden hamsters were treated with N-nitrosobis-(2-oxopropyl)amine (BOP) and/or diethylstilbestrol (DES) for lifetime. After BOP treatment the hamsters developed high incidences of pancreatic neoplasms, but DES failed to show any effect on these or other tumours.

Effect of stress on perceived intoxication and the blood alcohol curve in men and women

To determine the influence of stress on intoxication and blood alcohol concentration (BAC) 60 healthy male and female volunteers were exposed to a cold pressor test, distressing film, or control condition after consuming a moderate dose of alcohol. Two measures of perceived intoxication suggested a sobering effect of acute stressors. In addition, Ss viewing the distressing film showed longer latency to peak BAC than Ss in the control condition. As BAC began to fall, the cold pressor test initially increased rate of alcohol elimination. These stress-induced changes in intoxication and the BAC curve support a biobehavioral model in which stress may increase alcohol use partly because it attenuates alcohol's psychopharmacological impact.