Hostility, cultural orientation, and casual blood pressure readings in African Americans.

Evidence suggests that hostility correlates with blood pressure levels in African-American samples. However, some studies have reported an inverse relationship, while others have found the relationship between blood pressure and hostility to be positive. Other literature suggests health outcomes in general, and blood pressure in particular, are related to cultural orientation in African-American samples. In the present study, six casual measures of blood pressure and heart rate in a sample of 90 African-American college students were aggregated and correlated with measures of hostility and cultural orientation. Correlational and regression analyses revealed a weak positive relationship between hostility and systolic blood pressure. The relationships between the cardiovascular measures and cultural orientation were more consistent. The tendency to embrace mainstream Euro-American values, such as materialism, individuality, and competitiveness, was associated with more rapid heart rate and higher diastolic blood pressure levels for both men and women. The relationship between systolic blood pressure and cultural orientation emerged for men only. The findings encourage further research into the relationship between personality variables and cardiovascular activity in African-American samples.

Coping strategies in families of children with sickle cell disease.

OBJECTIVE: To examine the impact of family environment, morbidity, and socioeconomic status (SES) on coping strategies in families of children with sickle cell disease. DESIGN: A cross-sectional study. METHODS: The study sample consisted of 40 mothers, 24 fathers, 40 patients, and 28 healthy siblings from 40 African-American families, each of which had only one child with sickle cell disease. Data were collected through the use of structured interviews utilizing a demographic questionnaire, the Family Environment Scale (FES), and the COPE. RESULTS: The results indicate that support-seeking coping strategies were employed more often by mothers in more cohesive families and siblings in less cohesive families, while increased growth (resilience) was experienced by siblings in less conflicted families. Patients in more religious families reported greater use of religion as a means of coping. Mothers of mildly affected patients used acceptance more frequently than those of severely affected patients, and fathers of severely affected patients more often sought emotional support. Mothers, fathers, and siblings in low SES families reported greater use of denial than did those in high SES families. CONCLUSION: Additional psychosocial research involving families (including fathers and siblings) dealing with sickle cell disease is needed to facilitate the utilization of adaptive coping strategies, thereby enhancing individual and family adjustment.

Cardiovascular reactivity in Zimbabwe.

OBJECTIVE: In this study, we examined the effects of residency and gender on cardiovascular reactivity to a speech stressor in 50 rural Zimbabweans (24 males, 26 females) and 47 urban Zimbabweans (25 males and 22 females). METHODS: Participants were engaged in 4 periods: pre-task rest period, speech preparatory period, speaking task period, and the final recovery period. During each period, systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were assessed. RESULTS: There was a significant interaction between area of residence and period for SBP and HR. Urban residents exhibited greater SBP and HR during the speaking phase of the speech task than did rural residents. However, rural residents displayed more exaggerated HR reactivity during the speech preparatory phase as compared to the urban residents. No gender differences were observed on blood pressure or heart rate reactivity. CONCLUSION: In conclusion, the more exaggerated SBP and HR reactivity to the speaking phase among urban residents as compared to rural residents may be influenced by factors associated with urbanization.

Affective and physiological responses to racism: the roles of afrocentrism and mode of presentation.

Recent experiments have examined the subjective and physiological responses of African Americans to racism using video-taped vignettes or emotional imagery. These studies reported changes in mood and increases in cardiovascular (CV) and electromyographic (EMG) activity when analogs of the stressful situations were encountered. In addition, individual differences in responses were found to be related to various personality measures. The present study examined the mood, CV and EMG responses of 60 African-American women as they encountered social situations that included blatant and more subtle forms of racism. Half of the sample viewed both vignettes while the remainder imagined them. The relationship between responses and Afrocentrism, a measure related to black identity, was examined. Significant changes in heart rate, digital blood flow and facial muscle activity in the corrugator regions resulted. The most pronounced changes occurred when blatantly racist material was encountered. Mood changes tended to be stronger when material was imagined versus viewed. In general, Afrocentricity was not related to physiological responses to the scripts, though mood responses and Afrocentricity were related in several instances. The findings indicate that CV, as well as EMG and mood responses, are sensitive to various forms of racism presented in imagery and video modes.

Gender differences in mood and cardiovascular responses to socially stressful stimuli.

Filmed vignettes of socially stressful situations elicit changes in emotional states and physiological activation. Several studies have reported changes in mood and physiological activity in African Americans who encountered laboratory analogs of stressful situations. However, none have examined gender differences. African-American college students (52 women and 40 men) viewed two versions of one of two social stressors. In one instance, the perpetrator of the stressful circumstances was Caucasian, while in the other, a Black perpetrator was viewed. Order of viewing was counterbalanced. The scenes depicted either an unjust arrest for shoplifting or an encounter with a rude and threatening highway patrolman. Analyses of variance determined that increases in blood pressure occurred as the stressful scenes were viewed, though no increases occurred in response to the neutral material. Women reported more tension, distress and fear during the stressors while the men evidenced more pronounced elevations in blood pressure. The findings encourage further study of the impact of social stress on physiological and emotional processes.

Stem cell responses in myelosuppressed mice following sequential treatment with recombinant human interleukin 1 (rHuIL-1), recombinant murine interleukin 3 (rMuIL-3) and recombinant human macrophage colony-stimulating factor (rHuM-CSF).

In vivo, recombinant human interleukin 1 alpha (rHuIL-1 alpha) + recombinant human macrophage colony-stimulating factor (rHuM-CSF) (IL-1 + M-CSF) effectively serves as a rescue agent for myelosuppression by enhancing the recovery of hematopoietic stem cell (HSC) subpopulations following treatment with 5-fluorouracil (5-FU). Because in vitro studies have suggested that hematopoietic recovery in 5-FU-treated bone marrow (FUBM) may proceed from a 5-FU resistant, (IL-1 + IL-3 + M-CSF-responsive) high proliferative potential HSC subpopulation of colony forming cells (HPP-CFC), studies were carried out to determine whether the addition of recombinant murine interleukin 3 (rMuIL-3) (IL-3) to either IL-1 or IL-1 + M-CSF would further enhance the recovery of HSC subpopulations in myelosuppressed C57Bl/6 mice. With the exception of the HPP-CFC, IL-3 dampened, rather than enhanced, the accelerated recovery of 8 d and 12 d colony forming units-spleen (8 d and 12 d CFU-S) and the committed macrophage progenitor (CFU-M) associated with in vivo treatment with IL-1 alone. Similarly, IL-3 interfered with the enhanced recovery of those HSC subpopulations in FUBM influenced by the synergistic interaction of IL-1 + M-CSF. This interference, however, was observed only when the rMuIL-3 was administered on day 2 or 3 of a four-day treatment with IL-1 + M-CSF. There was, however, no evidence that IL-3 exerted a negative influence on the restoration of granulocytes in the myelosuppressed animals. Moreover, sequencing studies provided data suggesting that the dampening effects of IL-3 on the synergistic interaction of IL-1 + M-CSF resulted from both an enhanced differentiation of the more primitive HSC subpopulations and a significant, but preferential, mobilization of the more mature 8 d CFU-S and CFU-M to extramedullary organs and that the mobilization of these more mature HSC subpopulations was temporally linked to their generation from the recovering HPP-CFC and 12 d CFU-S subpopulations.

Synergy between recombinant human IL-1 alpha (rHuIL-1) and M-CSF (rHuM-CSF) during the recovery of murine hematopoietic activity in myelosuppressed animals: abbreviated versus chronic administration of rHuM-CSF.

The ability of highly purified, recombinant human macrophage colony-stimulating factor (M-CSF) and recombinant human interleukin 1 alpha (IL-1) to rescue hematopoietic activity from the myelosuppressive effects of 5-fluorouracil (5-FU) was investigated in the C57Bl/6 mouse. IL-1 (q24 h x 4) stimulated granulopoietic recovery in the 5-FU-treated animals and reduced the period of severe neutropenia associated with this drug by 7 days. Chronic M-CSF administration (q24 h x 14), on the other hand, resulted in a modest retardation of granulocyte recovery, and, when combined with IL-1, the chronic administration of M-CSF significantly dampened the accelerated recovery of granulopoietic activity observed with IL-1 alone. Consistent with their effects on neutrophil recovery, IL-1 alone markedly enhanced the recovery of the granulocyte erythrocyte macrophage megakaryocyte colony-forming units (CFU-GEMM), macrophage colony-forming units (CFU-M), and erythroid burst-forming units (BFUe) in the marrow, whereas M-CSF failed to demonstrate a significant influence on the restoration of these hematopoietic progenitors (with the exception of delaying the recovery of the BFUe). Unexpectedly, the combination of IL-1 plus M-CSF (q24 h, days 1-4) followed by M-CSF (q24 h, days 5-14) resulted in a more than additive stimulation of progenitor recovery in both the marrow and the spleen that was observed as early as day 3 following 5-FU treatment. Furthermore, in the absence of protracted M-CSF administration on days 5-14, the 4-day rescue with a combination of IL-1 plus M-CSF also resulted in a more than additive effect on the recovery from 5-FU-induced neutropenia. Collectively, these observations demonstrated that IL-1 and M-CSF can interact synergistically to stimulate granulopoietic recovery in the 5-FU-treated animal. However, the data also suggest that the continued administration of M-CSF following the 4-day IL-1 plus M-CSF rescue may interfere with the restoration of neutrophils in the myelosuppressed animal.

Absence of interleukin 1 alpha radioprotection in tumor-bearing animals: elevated plasma levels of prostaglandin E versus a preexisting primed marrow.

Recombinant human interleukin 1 (IL-1) administered as a "priming" agent 24 h prior to hematopoietically lethal doses of total body irradiation (TBI) confers radioprotection to normal C57B1/6 (B6) mice, but not to B6 tumor-bearing animals (TBAs) known to have altered hematopoietic steady states. Using the Lewis lung tumor (LLca) in the B6 mouse, studies were carried out to determine whether the failure of IL-1 to radioprotect the LLca TBA was related to a preexisting "primed" hematopoietic state in the TBA or resulted from inhibition of myelopoietic activity associated with the production of prostaglandin E (PGE) by, or in response to, the tumor. Both normal B6 and LLca B6 TBAs were injected (every 24 h x 1-5) with 100 micrograms of indomethacin (IND) prior to the administration of IL-1. A single treatment with IND was sufficient to reduce the elevated levels of PGE found in the plasma of the TBAs. After five treatments, IND reduced the PGE level to below that of controls. Neither the acute nor the protracted IND treatment, however, affected the expansion of the stem and progenitor cell compartments of the marrow in the LLca TBA. Furthermore, no evidence of restoration of the radioprotective properties of IL-1 was observed in TBAs pretreated with IND. Collectively, these data suggest that the failure of IL-1 to provide radioprotection to the LLca TBA is not a direct result of the elevated plasma PGE levels associated with growth of the LLca tumor. In addition, these studies provide insight into the importance of examining in vivo effects of biological molecules in altered, as well as normal, physiological states.

Interleukin-1 alpha protects against the toxicity associated with combined radiation and drug therapy.

A dose of total body irradiation sufficient to cause 70% mortality within 30 days (9.5 Gy) and maximally tolerated doses of either adriamycin (10 mg/kg) or cis-dichlorodiammine platinum (8 mg/kg) were administered to C57B1/6 mice and animal survival used as an index of toxicity. Whereas the nature of the toxicity resulting from the radiation alone was hematopoietic, the addition of either drug to the total body irradiation resulted in a pattern of animal death more consistent with that of gastrointestinal toxicity (100% dead within 7 days). However, if the radiation was delivered as a regional abdominal exposure, rather than total body, the gastrointestinal death observed following the combination of total body irradiation drug was not observed. The administration of 2.5 x 10(5) U IL-1 v24 hr prior to total body irradiation demonstrated significant protection against this dose of radiation (90% survival vs 30% survival). Similar protection was also observed when the IL-1 was administered 24 hr prior to the combination of total body irradiation with either drug. While these observations suggested that the IL-1 was protecting against gastrointestinal toxicity, subsequent studies demonstrated that IL-1, in addition to accelerating hematopoietic recovery following radiation insult, was equally effective in advancing the repopulation of the stem cell (CFU-GEMM) and progenitor cell (CFU-M and CFU-GM) compartments following drug treatment. Collectively, the data from these studies demonstrate that the lethal effects resulting from combined total body irradiation + drug treatment contain both a gastrointestinal and a hematopoietic component.

Altered radioprotective properties of interleukin I alpha (IL-1) in non-hematologic tumor-bearing animals.

The radioprotective properties of IL-1 were investigated in the respective murine hosts for the Lewis lung (LLca) and EMT-6 tumors. For these studies, doses of total body irradiation were selected for the C57B1/6 (9.5 Gy) and Balb/c (7.5 Gy) mice that resulted in a 60% mortality over a 30-day interval. When a "priming" dose of 2.5 x 10(5) U IL-1 was administered 24 hr prior to the radiation exposure, animal mortality was markedly reduced (60% vs 5-10%). Under identical experimental conditions, however, the presence of either the LLca or the EMT-6 tumors in their respective host strains was found to compromise the level of radioprotection conferred by this priming dose of IL-1. In Balb/c mice bearing the EMT-6 tumor, a priming dose of IL-1 resulted in only a modest level of radioprotection when compared to non-tumor-bearing control animals (median animal survival increased by 11.5 days). In C57B1/6 mice bearing the LLca tumor, IL-1 failed to demonstrate any evidence of radioprotection. Following a sublethal dose of total body irradiation, the appearance of an accelerated repopulation of the stem cell (8d CFUs and CFU-GEMM) and the myeloid progenitor (CFU-M) compartment in the marrow of the IL-1 primed EMT-6, but not the LLca, tumor-bearing animals was consistent with the hypothesis that the mechanism leading to radioprotection in IL-1 primed rodents involves an accelerated recovery of hematopoietic activity. It was also noted that the presence of the EMT-6 tumor was associated with an increase in the "radiosensitivity" of the Balb/c mouse. Collectively, these data suggest that the use of biological modifiers should be examined under altered physiological conditions prior to attempting to translate them into the clinic.

Effects of posture on cardiac dynamics during visual search.

Cardiovascular psychophysiologists are employing emerging non-invasive technologies to chart the changes in a variety of parameters of cardiac activity as psychological tasks are performed. One technique, impedance cardiography, makes it possible to assess cardiac output and contractile force while psychological tasks are being performed. This study was designed to determine if facilitating the venous return of blood from the legs would alter the pattern of cardiac changes that have been noted in earlier impedance cardiographic studies of the effects of psychological challenge. Twenty normotensive males performed visual search in upright, sitting and reclining positions and impedance cardiographic assessments of cardiac output and stroke volume, and an index of contractility were obtained. In addition, heart rate and two systolic time intervals were measured. As expected, decreases in stroke volume occurred as heart rate increased during visual search. Hence cardiac output (heart rate X stroke volume) remained stable. Higher levels of cardiac output, stroke volume and contractility were recorded in the reclining versus the upright position. However, the patterns of cardiac activity did not differ before, during and after performance when body position was altered. Hence, posture altered the absolute levels of several cardiac parameters, but did not affect the configuration of cardiac changes associated with performing a mildly challenging task.

Cardiac responses to psychological tasks: impedance cardiographic studies.

In a series of studies, cardiac activity, assessed with an impedance cardiograph, was monitored as college students performed either a visual search or pursuit rotor task. Heart rate, systolic time intervals, stroke volume, cardiac output and the Heather (1969) index of contractility were measured before, during and after performance. In the first study, visual search did not affect the participants' (N = 44) level of cardiac output or their length of the pre-ejection period. It is likely that the lack of charge in cardiac output resulted from a fall in stroke volume and in the Heather index while the task was performed. Heart rate was most rapid during performance and emerged as the only measure affected by the withdrawal of monetary incentives for failure to solve the visual search problem. In the second study, 40 subjects performed a pursuit rotor task and increases in cardiac output as well as changes in all of the other cardiac measures occurred. The level of task difficulty influenced the extent of heart rate increases and stroke volume decreases during performance. An additional 20 male subjects participated in a third study in which the level of difficulty of the pursuit rotor task was signalled and the order of the levels of difficulty was balanced across trial blocks. Under these conditions, the changes in cardiac activity before, during and after performance were similar to those observed in the first two studies. Heart rate was the only measure sensitive to the level of task difficulty. In general, the findings underscore the sensitivity of heart rate to changes in subtle aspects of psychological situations. To enlist increases in cardiac output and inotropic parameters extensive alterations in behavioral state are required.

Individual difference in anticipatory physiological responses to signaled stress: role of locus of control and autonomic balance.

Anticipatory cardiac activity to a signaled stressful event was hypothesized to be related to individual differences in locus of control and to autonomic balance. Subjects experienced 5 trials of a 105-db burst of white noise that was signaled by a milder tone. Significant increases in electrodermal as well as heart-rate responses occurred after the stress tone. While anticipating stress, the 10 subjects designated as having high levels of coherence between heart-rate and respiratory activity (high parasympathetic balance) showed reduced heart-rate and respiratory activity (high parasympathetic balance) showed reduced heart-rate variability over the 10 subjects with low coherence. Locus of control was not related to anticipatory activity. Anticipatory cardiac activity is discussed in light of two current psychophysiological models of attention.