Micron-pore-sized metallic filter tube membranes for filtration of particulates and water purification.

Robust filtering techniques capable of efficiently removing particulates and biological agents from water or air suffer from plugging, poor rejuvenation, low permeance, and high backpressure. Operational characteristics of pressure-driven separations are in part controlled by the membrane pore size, charge of particulates, transmembrane pressure and the requirement for sufficient water flux to overcome fouling. With long term use filters decline in permeance due to filter-cake plugging of pores, fouling, or filter deterioration. Though metallic filter tube development at ORNL has focused almost exclusively on gas separations, a small study examined the applicability of these membranes for tangential filtering of aqueous suspensions of bacterial-sized particles. A mixture of fluorescent polystyrene microspheres ranging in size from 0.5 to 6 microm in diameter simulated microorganisms in filtration studies. Compared to a commercial filter, the ORNL 0.6 microm filter averaged approximately 10-fold greater filtration efficiency of the small particles, several-fold greater permeance after considerable use and it returned to approximately 85% of the initial flow upon backflushing versus 30% for the commercial filter. After filtering several liters of the particle-containing suspension, the ORNL composite filter still exhibited greater than 50% of its initial permeance while the commercial filter had decreased to less than 20%. When considering a greater filtration efficiency, greater permeance per unit mass, greater percentage of rejuvenation upon backflushing (up to 3-fold), and likely greater performance with extended use, the ORNL 0.6 microm filters can potentially outperform the commercial filter by factors of 100-1,000 fold.

How do residents prioritize smoking cessation for young "high-risk" women? Factors associated with addressing smoking cessation.

BACKGROUND: Sixty-seven percent of physicians report advising their smoking patients to quit. Primary care residents' priorities for preventive health for a young "high-risk" female are unknown. Factors related to residents addressing smoking also need examining. METHODS: One hundred residents completed a survey about preventive health issues for a woman in her 20s "who leads a high-risk lifestyle." Residents indicated which topics they would address, and the likelihood that they would address each of 12 relevant preventive health topics, their outcome expectancies that the patient would follow their advice on each topic, their confidence that they could address the topic, and perceived barriers for addressing the topic. RESULTS: Residents listed STD prevention most frequently. Drug use and smoking cessation were second and third most frequently listed. Residents who believed that the patient would follow their advice were more likely to list smoking cessation than residents who had lower outcome expectancies for that patient. Higher barriers were negatively related to addressing smoking cessation. CONCLUSIONS: When time is not a barrier, residents are likely to address smoking cessation. Teaching residents how to incorporate this subject into their clinical practice is needed. Raising residents' outcome expectancies may increase their likelihood of addressing smoking cessation.

Preparing for the end of life: preferences of patients, families, physicians, and other care providers.

To examine patients', families', and health care providers' preferences regarding preparation for the end of life, attributes of preparation were generated in qualitative focus group discussions and subsequently tested for generalizability in a quantitative national survey. Respondents from all groups showed consensus on the importance of naming someone to make decisions, knowing what to expect about one's physical condition, having financial affairs in order, having treatment preferences in writing, and knowing that one's physician is comfortable talking about death and dying. Patients were more likely than physicians to want to plan funerals and know the timing of death and less likely than all other groups to want to discuss personal fears. Participants in care of dying patients agree overwhelmingly with the importance of preparation. However, significant barriers to preparation impede it from being a common part of clinical encounters. Further research and training are needed to ensure that the desire for greater preparation is translated into improved action toward preparation in medical practice.

Development and reliability of a Telephone-Administered Perceived Racism Scale (TPRS): a tool for epidemiological use.

The conceptualization of perceived racism as a chronic stressor is relatively new to epidemiology. The Telephone-Administered Perceived Racism Scale (TPRS) captures the complexity of racism within five scales: Experience of Racism (by Blacks as a group and by the respondent), Emotional Responses, Behavioral Responses, Concern for Child(ren), and Past Experiences of Racism. The TPRS was developed for employed Black women. Exploratory factor analyses and tests of internal consistency were completed with 476 Black women, aged 36-53. Factor analyses on their responses to racism yielded five factors: passive emotions, active emotions, passive behaviors, internal active behaviors, and external active behaviors. Alpha reliability values ranged from 0.75 to 0.80 for the active and passive emotions subscales, from 0.59 to 0.69 for the passive behaviors subscale, and greater than 0.76 for both active behaviors subscales. Alpha reliabilities were 0.82, 0.90, 0.88, and 0.82 for Past Experiences, Concern for Child(ren), Experience of Racism--Personal, and Experience of Racism--Group, respectively. Another 30 Black women were queried for test-retest reliability, with values ranging from 0.61 to 0.82. The TPRS was found to be reliable and should serve as a useful epidemiological tool in the examination of the effects of perceived racism on Black women's health.

Factors considered important at the end of life by patients, family, physicians, and other care providers.

CONTEXT: A clear understanding of what patients, families, and health care practitioners view as important at the end of life is integral to the success of improving care of dying patients. Empirical evidence defining such factors, however, is lacking. OBJECTIVE: To determine the factors considered important at the end of life by patients, their families, physicians, and other care providers. DESIGN AND SETTING: Cross-sectional, stratified random national survey conducted in March-August 1999. PARTICIPANTS: Seriously ill patients (n = 340), recently bereaved family (n = 332), physicians (n = 361), and other care providers (nurses, social workers, chaplains, and hospice volunteers; n = 429). MAIN OUTCOME MEASURES: Importance of 44 attributes of quality at the end of life (5-point scale) and rankings of 9 major attributes, compared in the 4 groups. RESULTS: Twenty-six items consistently were rated as being important (>70% responding that item is important) across all 4 groups, including pain and symptom management, preparation for death, achieving a sense of completion, decisions about treatment preferences, and being treated as a "whole person." Eight items received strong importance ratings from patients but less from physicians (P<.001), including being mentally aware, having funeral arrangements planned, not being a burden, helping others, and coming to peace with God. Ten items had broad variation within as well as among the 4 groups, including decisions about life-sustaining treatments, dying at home, and talking about the meaning of death. Participants ranked freedom from pain most important and dying at home least important among 9 major attributes. CONCLUSIONS: Although pain and symptom management, communication with one's physician, preparation for death, and the opportunity to achieve a sense of completion are important to most, other factors important to quality at the end of life differ by role and by individual. Efforts to evaluate and improve patients' and families' experiences at the end of life must account for diverse perceptions of quality. JAMA. 2000;284:2476-2482.

In search of a good death: observations of patients, families, and providers.

Despite a recent increase in the attention given to improving end-of-life care, our understanding of what constitutes a good death is surprisingly lacking. The purpose of this study was to gather descriptions of the components of a good death from patients, families, and providers through focus group discussions and in-depth interviews. Seventy-five participants-including physicians, nurses, social workers, chaplains, hospice volunteers, patients, and recently bereaved family members-were recruited from a university medical center, a Veterans Affairs medical center, and a community hospice. Participants identified six major components of a good death: pain and symptom management, clear decision making, preparation for death, completion, contributing to others, and affirmation of the whole person. The six themes are process-oriented attributes of a good death, and each has biomedical, psychological, social, and spiritual components. Physicians' discussions of a good death differed greatly from those of other groups. Physicians offered the most biomedical perspective, and patients, families, and other health care professionals defined a broad range of attributes integral to the quality of dying. Although there is no "right" way to die, these six themes may be used as a framework for understanding what participants tend to value at the end of life. Biomedical care is critical, but it is only a point of departure toward total end-of-life care. For patients and families, psychosocial and spiritual issues are as important as physiologic concerns.

The perceived racism scale: a multidimensional assessment of the experience of white racism among African Americans.

The experience of racism is a complex, multidimensional phenomenon. At present, there are few instruments that attempt to capture the experience of racism in all of its complexity. For this study, a new instrument, the Perceived Racism Scale, has been constructed to assess the experience of racism in African Americans in a multidimensional manner. The scale not only provides a measure of the frequency of exposure to many manifestations of racism (including individual and institutional, overt and covert, attitudinal, behavioral, and cultural), but takes a step forward in more comprehensively measuring the experience of racism by assessing emotional and behavioral coping responses to racism. These responses are measured with respect to exposure to racism in three situational domains: on the job, in academic settings, and in the public realm. Measurement of responses to a fourth domain, that of exposure to racist statements, is also included. It is hoped that the Perceived Racism Scale will facilitate a more comprehensive understanding of the experience of racism among African Americans and, through its use in research and clinical settings, will ultimately move us closer to reducing the prevalence and potentially untoward effects of racism.

Effects of racist provocation and social support on cardiovascular reactivity in African American women.

It has been speculated that exposure to the chronic stress of racism contributes to the high rates of hypertension among African Americans. Social support may buffer the effects of stress on cardiovascular (CV) health by attenuating stress-induced CV responses that have been linked to hypertension. In this study we investigated the effects of racism and social support on CV reactivity in African American women. Participants showed greater increases in CV and emotional responses while responding and listening to racist provocation. Augmented blood pressure (BP) persisted through recovery following racial stress. Participants receiving no support showed the greatest increases in anger during racist provocation. No significant effects were seen for support on CV reactivity. These results provide some of the first evidence that interactive confrontation with racism elicits significant increases in CV reactivity and emotional distress. Furthermore, individuals receiving less support may be at greater risk for the potentially health-damaging effects of racial stress. These findings may have significant implications for the health of African Americans.

Patterns and stability of cardiovascular responses to variations of the cold pressor test.

Test-retest reliabilities and patterns of heart rate and blood pressure responses were examined using variations in the cold pressor test in 113 normotensive white college men. Comparisons were made of stimulus site (forehead vs. foot) and bodily posture (seated vs. supine) across four separate groups of men. The stability of cardiovascular responses was examined over a 2-week-test-retest interval. Different cardiovascular response patterns emerged as a function of stimulation site and posture. Systolic and diastolic blood pressure increases were accompanied by bradycardia in the forehead cold pressor task but by tachycardia in the foot cold pressor task. Systolic blood pressure increases were larger for foot than for forehead stimulation. Heart rate increases were larger for supine than for seated men. Effects on response were independent of postural differences at baseline, and there were no stimulation site by posture interactions. The cardiovascular responses to stimulation did not attenuate across sessions in any experimental condition but were more reliable for foot than for forehead stimulation and for supine than for seated posture. Short-term stability for changes to the task approached that for baseline and task and was higher than has been reported elsewhere.

Assessment of cardiovascular reactivity: a methodological overview.

The purpose of this article is to provide an overview of the rationale and methodological procedures for the assessment of cardiovascular reactivity. We hope that this introduction to the field will facilitate studies on cardiovascular reactivity in populations of Africa and encourage American-African collaborative projects.

Autonomic reactivity and hypertension in blacks: a review and proposed model.

In summary, according to the proposed model, race is viewed as a sociocultural designation that denotes differential exposure to chronic social stressors. It is proposed that black Americans are exposed to significantly more chronic social stressors than are white Americans. Many of these chronic social stressors have been associated with hypertension prevalence in epidemiological studies. Furthermore, chronic stress has been shown to augment cardiovascular reactivity to acute stress in both animals and humans, and to increase sodium retention in spontaneously hypertensive rats. Acute stress has also been demonstrated to increase sodium retention in humans. The essential element of our model is that chronic social stressors that are represented more within the black American population due to historical factors are related to an increase in sodium sensitivity and retention. This altered sodium metabolism may be further augmented by biological, behavioral, and psychological risk factors for hypertension and modulated by stress coping resources. It is hoped that this model will serve as a stimulus for further research on the biopsychosocial aspects of autonomic reactivity and hypertension in blacks.

Altered pituitary hormone response to naloxone in hypertension development.

Endogenous opioid regulation of blood pressure is altered during stress in young adults at risk for hypertension. We studied the effects of the opioid antagonist naloxone on the secretion of corticotropin and beta-endorphin during psychological stress in young adults with mildly elevated casual arterial pressures. Naloxone-induced secretion of both corticotropin and beta-endorphin was significantly diminished in persons at enhanced risk for hypertension compared with the low blood pressure control group. Results suggest that opioidergic inhibition of anterior pituitary function is altered in hypertension development.

Neuropeptide and cardiovascular responses to intravenous catheterization in normotensive and hypertensive blacks and whites.

Research suggests that heightened cardiovascular and neuroendocrine (typically catecholamine) responses to stressors may lead to the development of hypertension and that there may be race differences in patterns of reactivity that are potentially pathogenic. Certain neuropeptides exert profound effects on blood pressure (BP) and heart rate (HR), yet no published studies have examined relationships between these peptides, hypertensive status, race, and reactivity. Seventeen Black and 20 White normotensive and borderline-hypertensive male 19- to 50-year-olds underwent intravenous catheterization while cardiovascular and neuropeptide responses to the stress of being catheterized were examined. Results indicate that, in response to the stressor, Black hypertensives, showed significantly lower endorphin levels compared to Black normotensives, and White hypertensives showed significantly higher levels of beta-endorphin compared to White normotensives. Groups were not significantly different in endorphin levels at recovery. Black hypertensives also showed significantly higher stressor-induced HR and systolic and diastolic BP compared to White hypertensives and normotensives. Lower levels of beta-endorphin and lower urine sodium excretion were associated with higher BP and HR.