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Biomedical subjects

M A Zimmerman

Publications and source records attributed to M A Zimmerman.

At least 19 recordsLinked to original sources
PubMed2001

Organ preconditioning.

The initial discovery of cardiac preconditioning has evolved into an exciting series of practical surgical applications. An enormous amount of evidence demonstrating both the safety and efficacy of ischemic preconditioning is available from animal studies. The challenging premise of intentionally subjecting patients and their organs to transient ischemia has acted as a formidable psychological and ethical impediment to the widespread clinical application of organ preconditioning. A more palatable alternative to ischemic preconditioning now involves approved medications designed to manipulate the cellular machinery mediating ischemic preconditioning. Pharmacologically induced preconditioning seems to confer equal organ protection. The relatively brief (but surgically relevant) window of protection provided by strategies such as ischemic preconditioning or adenosine agonists and potassium-adenosine triphosphate channel openers may, in the future, be extended. We have developed and reported the feasibility of liposomal delivery of heat shock protein to cardiac myocytes with subsequent protection against sepsis-induced dysfunction. Targeted strategies will ultimately broaden the therapeutic potential of organ preconditioning.

Animals↗
PubMed2001

The case for beta-adrenergic blockade as prophylaxis against perioperative cardiovascular morbidity and mortality.

Perioperative morbidity and mortality are frequently cardiac in origin. Many studies have prospectively attempted to define risk factors for cardiac ischemic events. Although we can now identify high-risk patients, optimal cardioprotective management strategies remain unclear. Treatment with beta-adrenergic antagonists decreases myocardial oxygen consumption and is generally well tolerated. This article reviews the physiologic and clinical basis for using these agents as prophylaxis against cardiovascular events in high-risk surgical patients.

Adrenergic beta-Antagonists↗
PubMed2001

Psychosocial outcomes of urban African American adolescents born to teenage mothers.

This is a study of psychosocial outcomes of adolescents born to teenage mothers. Adolescents'problem behaviors, psychological well-being, social support, school variables, and sexual behaviors are compared across three groups- those born to mothers 17 or younger, mothers 18-19 years old, and mothers 20 or older. Analyses from two samples of African American adolescents from Maryland (n = 205) and Michigan (n = 570) are reported. The results from both samples indicate that mother's age at birth is unrelated to adolescents' psychosocial outcomes. These two studies add to the limited number of analyses that examine adolescent outcomes for children of teen mothers. The results suggest that efforts to understand social structural determinants of healthy and problematic adolescent development may be more informative than examining the effects of mother's age. They also suggest that teen pregnancy prevention programs may be more effective if they are part of a larger prevention strategy that incorporates social structural change efforts and not only a focus on individual level change.

Adolescent↗
PubMed2001

Vascular cell adhesion molecule--1 expression is obligatory for endotoxin-induced myocardial neutrophil accumulation and contractile dysfunction.

BACKGROUND: Sepsis-induced cardiac dysfunction occurs commonly in critically ill patients and is associated with high mortality rates. Neutrophils play a central role in sepsis-induced lung and liver injury; however, the mechanism of sepsis-induced cardiac dysfunction remains unclear. Vascular cell adhesion molecule-1 (VCAM-1) has been implicated in neutrophil-mediated liver injury during endotoxemia and is also expressed in myocardium. The purposes of this study were to examine the temporal relationship of myocardial VCAM-1 expression with neutrophil accumulation during endotoxemia and to determine whether VCAM-1 mediates neutrophil accumulation and cardiac dysfunction during endotoxemia. METHODS: Mice were subjected to lipopolysaccharide (LPS; 0.5 mg/kg, intraperitoneally). Myocardial VCAM-1 expression and neutrophil accumulation were determined by immunofluorescence staining. Cardiac performance with or without VCAM-1 blocking antibody (5 mg/kg, intravenously) was determined by the Langendorff technique. RESULTS: LPS caused a time-dependent increase in both myocardial VCAM-1 expression and neutrophil accumulation. At 6 hours after LPS, the immunofluorescent intensity for VCAM-1 increased from 2.5 +/- 0.6 x 10(6) in saline solution controls to 19.9 +/- 3.5 x 10(6) (P <.05, analysis of variance), and neutrophil count increased from 2.4 +/- 1.7/mm(2) in saline solution controls to 13.0 +/- 2.5/mm(2) (P <.05). Left ventricular developed pressure was decreased maximally at 6 hours after LPS compared with saline solution controls (29.1 +/- 1.1 mm Hg vs 53.1 +/- 3.9 mm Hg; P <.05). Treatment with VCAM-1 monoclonal antibody abrogated both myocardial neutrophil accumulation and cardiac dysfunction during endotoxemia. CONCLUSIONS: LPS-induced myocardial dysfunction is associated with increased expression of VCAM-1 and with neutrophil accumulation. Blockade of VCAM-1 abrogates myocardial neutrophil accumulation and preserves cardiac function during endotoxemia, which supports a role for VCAM-1 as a therapeutic target for myocardial protection during sepsis.

Animals↗
PubMed2001

Forging collaborative partnerships to enhance family health: an assessment of strengths and challenges in conducting community-based research.

Community-based research has emerged as a vital strategy for developing effective, culturally relevant health interventions. This article describes the strengths and challenges of building a collaborative research partnership based on equality between academic researchers, public health practitioners, and representatives from community-based organizations. The model of collaboration adopted for the Fathers and Sons Project is described and examples of model applications are discussed. Lessons learned in the form of strengths/benefits and potential pitfalls in developing a community-based intervention designed to enhance the health behaviors of African American nonresidential fathers and their sons are provided.

Black or African American↗
PubMed2000

Inhibitory tagging in inhibition of return is affected in schizophrenia: evidence from the stroop task.

L. J. Fuentes, A. B. Vivas, and G. W. Humphreys (1999b) showed that stimulus processing is affected when stimuli are presented to locations subject to inhibition of return. They argued that activated representations of stimuli presented at inhibited locations are disconnected from their associated responses through an "inhibitory tagging" mechanism occurring in inhibition of return. In the present research, the authors asked whether such a mechanism is affected in people with schizophrenia. Healthy adults and patients with schizophrenia performed a Stroop task in an inhibition of return paradigm. Healthy adults showed a reduction in the Stroop interference when stimuli were presented at inhibited locations, a result that agrees with the inhibitory tagging mechanism hypothesis and replicates previous findings. However, patients with schizophrenia did not show such a reduction, a result suggesting that they have a deficit in inhibitory processing occurring in inhibition of return.

Adult↗
PubMed2000

Gender differences in HIV-related sexual risk behavior among urban African American youth: a multivariate approach.

Alcohol and other drug (AOD) use during sexual encounters, sexual partner's age, perceived HIV risk and perceived condom effectiveness were studied among 388 sexually active African American youth. Cluster analysis of condom use, number of partners, and frequency of sexual intercourse identified four groups: low risk, monogamy strategy, condom strategy, and high risk. Low-risk youth used condoms consistently and had few partners. High-risk youth used condoms inconsistently with many partners. Monogamy strategy youth used condoms inconsistently but had few partners. Condom strategy youth used condoms consistently with a moderate number of partners. The high-risk group included more males and the monogamy group included more females. High-risk males reported more AOD use during sexual activity than all females, and low-risk or condom strategy males. Females had older partners, rated condoms as less effective and perceived lower HIV/AIDS risk than males. Results suggest differential HIV risk mechanisms by gender. Implications for gender-specific HIV prevention are discussed.

Adolescent↗
PubMed1999

Inhibitory processing in visuospatial attention in healthy adults and schizophrenic patients.

This study assessed visuospatial attention in healthy adults and medicated schizophrenic patients. Participants performed a visual orientation task in which a peripheral cue was followed. at different intervals, by a target presented either at valid or invalid locations. When the long stimulus onset asynchrony (SOA) was used, participants were presented with either a single peripheral cue (single-cue condition) or two cues, the peripheral cue followed by a central cue (the double-cue condition). Healthy adults showed marginal facilitation effects with the short SOA and similar inhibition of return effects with the long SOA in both single-cue and double-cue conditions. Schizophrenic individuals showed a big facilitation effect with the short SOA and normal inhibition of return with the long SOA in both cue conditions. Results with the short SOA replicated previous findings (Huey, E.D., Wexler, B.E., 1994. Schizophrenia Research 14, 57-63) but, in contrast, we did not observe blunted inhibition of return with the long SOA. An inspection of the differences in the procedures used in both studies may help both to account for the discrepancies and to reveal what processes involved in visuospatial attention are affected in schizophrenia.

Adult↗
PubMed1999

Resilience among urban African American male adolescents: a study of the protective effects of sociopolitical control on their mental health.

Resilience refers to the notion that some people succeed in the face of adversity. In a risk-protective model of resilience, a protective factor interacts with a risk factor to mitigate the occurrence of a negative outcome. This study tested longitudinally the protective effects of sociopolitical control on the link between helplessness and mental health. The study included 172 urban, male, African American adolescents, who were interviewed twice, 6 months apart. Sociopolitical control was defined as the beliefs about one's capabilities and efficacy in social and political systems. Two mental health outcomes were examined--psychological symptoms and self-esteem. Regression analysis to predict psychological symptoms and self-esteem over time were conducted. High levels of sociopolitical control were found to limit the negative consequences of helplessness on mental health. The results suggest that sociopolitical control may help to protect youths from the negative consequences of feelings of helplessness. Implications for prevention strategies are discussed.

Adolescent↗
PubMed1999

Posttraumatic stress disorder after injury: impact on general health outcome and early risk assessment.

OBJECTIVE: To evaluate prospectively components of general health outcome after trauma and to report on the further validation of the Michigan Critical Events Perception Scale (MCEPS), an instrument that predicts increased risk for posttraumatic stress disorder (PTSD). METHODS: Adults without neurologic injury admitted to a Level I trauma center in 1997 were interviewed during hospitalization. Baseline data included demographics, injury mechanism, Injury Severity Score, the Short Form 36 (SF36), and the MCEPS, which measures peri-traumatic dissociation (the sense of depersonalization or derealization during an injury event). Surveys sent by mail and completed 6 months later included the SF36 and civilian Mississippi Scale for PTSD. RESULTS: A total of 140 patients were interviewed; the 70% (n = 100 patients) who completed the 6-month assessment form the study group. Injuries were categorized as 71% blunt, 13% penetrating, and 16% burn. Mean Injury Severity Score was 13.7+/-0.52. PTSD at 6 months occurred in 42% of the patients and was directly related to MCEPS dissociation (p = 0.001; odds ratio = 3.1; 95% confidence interval, 1.6, 5.9). A stepwise linear regression explains 40% of the variance in 6-month SF36 general health outcome (adjusted R2 = 0.402). The model controls for individual factors related to dissociation, PTSD, and general health outcome. Development of PTSD was independently and inversely related to general health outcome as measured by the SF36 at 6 months (p < 0.001, beta = -0.404). The R2 change of 0.132 for PTSD (vs. 0.082 for 6-month physical function) illustrates that PTSD contributes more to the patient's perceived general health at 6 months than the degree of physical function or injury severity. CONCLUSIONS: Within hours of injury, the MCEPS identifies patients who are three times more likely to develop PTSD. PTSD compromises self-reported general health outcome in injured adults independent of baseline status, Injury Severity Score, or degree of physical recovery. These data suggest that psychological morbidity is an important part of the patient's perceived general health.

Adult↗
PubMed1999

Posttraumatic stress disorder in injured adults: etiology by path analysis.

OBJECTIVE: Posttraumatic Stress Disorder (PTSD) impairs outcome from injury. We present a path analysis of factors related to the development of PTSD in injured adults. METHODS: A prospective cohort of 250 patients without severe neurotrauma was evaluated by interview during admission and by mailed self-report 6 months later. Data were gathered from the trauma registry (age, injury mechanism, and Injury Severity Score), social history (gender, income, education, and social support), and survey instruments. Baseline assessment used the Michigan Critical Events Perception Scale (peritraumatic dissociation and subjective threat to life), the Life Experience Survey (stressful exposure history), and the SF36 (general and mental health). PTSD at 6 months was identified with the civilian Mississippi Scale for PTSD. Data are listed as mean +/- SEM or percent (%). Path analysis was conducted by linear regression and significant (p<0.05) variables are shown. Factors are listed with the standardized beta. A negative beta suggests a protective effect. RESULTS: The 176 patients (72%) who completed the 6-month follow-up were 37.7+/-0.88 years old; 75% were men; and blunt (70%), penetrating (13.5%), and burn (16.4%) mechanisms caused the injuries. Assault was involved in 14.5% of the cases. Average income was $44,300+/-2,700/yr, education was 13.0+/-0.15 years, and Injury Severity Score was 13.9+/-0.50. A total of 42.3% of the patients developed PTSD. The 39.7% of the variance in PTSD explained by the model was due to intentional injury (beta = 0.27), male gender (beta = -0.21), age (beta = -0.20), peritraumatic dissociation (beta = 0.174), baseline mental health (beta = -0.21), and prior life-threatening illness (beta = -0.29). Peritraumatic dissociation was due to the patient's sense of threat to life (beta = -0.47), and threat was related to Injury Severity Score (beta = 0.2), assault(beta = 0.14), education (beta = -0.15), and age (beta = -0.19). Baseline SF36 mental health was related to social support (beta = 0.27) and income (beta = 0.21). Income was contingent on education (beta = 0.21). CONCLUSION: PTSD occurred in 42.3% of injured adults 6 months after trauma and was related to assault, dissociation, female gender, youth, poor mental health, and prior illness. By modeling PTSD, we may learn more of the etiology, risk stratification, and potentials for the treatment of this common and important morbidity of injury.

Adaptation, Psychological↗
PubMed1998

Psychosocial factors and high-risk sexual behavior: race differences among urban adolescents.

Adolescence is a period of sexual experimentation. We examined psychosocial predictors of high-risk sexual behavior and condom use. The sample included 824 ninth-graders, most of whom are African American. We conducted separate analyses for whites and African Americans. Predictors included alcohol and substance use, delinquency, prosocial behaviors, and family and peer influences. We found that problem behaviors predicted high-risk sexual behavior, but the effects were stronger for white youth. We also found that friends' behaviors were more predictive than family influences, except for family conflict. In general, the models explained more variance for white youths than for African-American youths. The results suggest that problem behavior theory and social interactions theory may be most relevant for white youth and that other models may be necessary to explain high-risk sexual behavior among African-American youths.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Psychosocial factors limit outcomes after trauma.

BACKGROUND: Psychological morbidity compromises return to work after trauma. We demonstrate this relationship and present methods to identify risks for significant psychological morbidity. METHODS: Thirty-five adults were evaluated prospectively for return to functional employment after injury using demographic data, validated psychological and health measures, and the Michigan Critical Events Perception Scale. Evaluation was conducted at admission and at 1 and 5 months after injury. RESULTS: Poor return to work at 5 months was attributable to physical disability (p < 0.05) and psychological disturbance (p < 0.05) in a regression model that controlled for preinjury employment and psychopathologic factors as well as injury severity. A high score on the Impact of Events Scale administered during acute admission predicted development of acute stress disorder at 1 month (p < 0.01, odds ratio (OR) = 9.4) and posttraumatic stress disorder at 5 months (p < 0.05, OR = 6.7). Peritraumatic dissociation on the Michigan Critical Events Perception Scale was predictive for development of acute stress disorder (p < 0.05, OR = 5.8) at 1 month and posttraumatic stress disorder (p < 0.05, OR = 7.5) at 5 months. CONCLUSION: Psychological morbidity after injury compromises return to work independent of preinjury employment and psychopathologic condition, Injury Severity Score, or ambulation. A high Impact of Events Scale score or peritraumatic dissociation at admission predicts this morbidity.

Activities of Daily Living↗
PubMed1998

Sexual risk behavior among youth: modeling the influence of prosocial activities and socioeconomic factors.

Sexual activity among high-school-aged youths has steadily increased since the 1970s, emerging as a significant public health concern. Yet, patterns of youth sexual risk behavior are shaped by social class, race, and gender. Based on sociological theories of financial deprivation and collective socialization, we develop and test a model of the relationships among neighborhood poverty; family structure and social class position; parental involvement; prosocial activities; race; and gender as they predict youth sexual risk behavior. We employ structural equation modeling to test this model on a cross-sectional sample of 370 sexually active high-school students from a midwestern city; 57 percent (n = 209) are males and 86 percent are African American. We find that family structure indirectly predicts sexual risk behavior through neighborhood poverty, parental involvement, and prosocial activities. In addition, family class position indirectly predicts sexual risk behavior through neighborhood poverty and prosocial activities. We address implications for theory and health promotion.

Adolescent↗
PubMed1997

Preventing the spread of AIDS in youth: principles of practice from 11 diverse projects.

PURPOSE: The purpose of this study was to identify the factors that contributed to intervention effectiveness in acquired immunodeficiency syndrome (AIDS) prevention projects targeting youth. METHODS: Eleven AIDS prevention projects funded by the Robert Wood Johnson Foundation whose target populations consisted of at least 60% youth were studied. A blended methodology resulted in quantitative data (i.e., survey responses) from all 11 projects supplemented with qualitative data (i.e., open-ended interviews) drawn from in-depth site visits to six projects. RESULTS: Projects reported using a mean of 16.6 intervention activities (selected from a list of 30). Six activities were used by all 11 projects. Small group discussions were rated as one of three most effective activities by 72.7% of the projects that used them. Project staff identified three elements of effective interventions: involvement of peer educators, recognition of the role of adults (e.g., parents, teachers), and use of structured settings to gain access to the target population (e.g., schools, clubs). CONCLUSIONS: The most powerful strategies described by project staff for reaching adolescents at risk for human immunodeficiency virus (HIV) transmission also bring considerable challenges. Opportunity costs associated with using peer educators, gatekeeper support, and structured settings may include limited control of the message, impaired credibility, and failure to reach those youth at greatest risk of HIV infection, respectively. Health educators will do well to consider the advantages and disadvantages of these factors when developing, implementing, and evaluating AIDS prevention programs for youth.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Validity of adolescents' report of maternal age.

Examined the validity of adolescents' reports of their mother's age. Most research on the validity of self-report focuses on personal behaviors such as alcohol and substance use, or response bias due to social desirability. Few studies investigate the validity of adolescents reporting of nonsensitive information. Data from 80 mother-adolescent pairs were collected. The sample included 9th graders from four high school English classes, equal numbers of males and females, and 15% African Americans. The correlation between mothers' reports and youths' reports of mother's age was .99, and 95% of the youth were within a year of their mother's correct age. No race or gender differences were found. These results allow researchers to examine adolescent outcomes for youth born to teen mothers without the expense of also collecting data from their mothers. Results also suggest that adolescents' self-reports of other nonsensitive familial data may also be valid.

Adolescent↗
PubMed1997

An HIV/AIDS prevention project for Mexican homosexual men: an empowerment approach.

In this intervention, participants design and implement an HIV/AIDS prevention project for Mexican homosexual men. The intervention is consistent with, and contributes to, empowerment theory because it enhances collective action, provides opportunities to develop knowledge and skills, creates needed resources, and includes shared control with professional and among participants. The intervention described provides an illustration of an empowering process and distinguishes itself from empowerment outcomes. An evaluation of the project is also described, but the outcomes were HIV/AIDS-related behaviors rather than psychological empowerment of the participants. The results suggest that the participants' HIV/AIDS knowledge and preventive behavior improved when compared to individuals who did not participate in the intervention. In addition, the intervention generated community change initiated by participants. Implications for designing interventions using an empowerment approach are discussed.

Acquired Immunodeficiency Syndrome↗