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Biomedical subjects

R S Zimmerman

Publications and source records attributed to R S Zimmerman.

At least 37 records · Page 2Linked to original sources
PubMed1996

A replication and elaboration of the esteem-enhancement model.

Adolescents treated in clinical settings for drug use problems are often observed to have low self-esteem. This has led some researchers to the belief that mood or personality characteristics of adolescents predispose them to drug use. However, longitudinal field studies have failed to confirm a direct relationship between low self-esteem and substance abuse (Petraitis et al. 1995). Evidently, if an important causal relationship exists between self-esteem and drug use in the nonclinical adolescent population, it is complex and mediated by other factors. To address this issue, explanatory theories are needed that can organize the relationships between drug abuse and its antecendent causes including low self-esteem. One of the few theoretical approaches that has been put forward for empirical verification is the esteem-enhancement theory of Kaplan, Johnson, and Bailey (1986a, 1987, 1988).

Adolescent↗
PubMed1996

Disaster related stresses, depressive signs and symptoms, and suicidal ideation among a multi-racial/ethnic sample of adolescents: a longitudinal analysis.

Longitudinal findings are presented on the relationships between disaster related stresses, depression scores, and suicidal ideation among a multi-racial/ethnic sample of adolescents (N = 4,978) all of whom have been exposed to Hurricane Andrew. Regression analysis showed that being female, hurricane generated stresses, low levels of family support, pre-hurricane suicidal ideation, and post-hurricane depression scores were significant predictors of post-hurricane suicidal ideation. Path analysis revealed that being female, low socioeconomic status, pre- and post-hurricane depression, high stress scores, low family support, and pre-hurricane suicidal ideation had significant direct/indirect effects on post-hurricane suicidal ideation.

Adaptation, Psychological↗
PubMed1996

Gender and ethnic differences in the prevalence of alcohol, cigarette, and illicit drug use over time in a cohort of young Hispanic adolescents in south Florida.

The purpose of this study was to describe patterns of substance use among young Hispanic adolescents of Cuban and Central/South American heritage, many of whom are recent immigrants to the U.S. At present there are very little epidemiologic data on these Hispanic ethnic subgroups, particularly for girls. A cohort of 848 middle school boys and girls in Miami, Florida completed questionnaires in 7th, 8th, and 9th grades concerning their use of alcohol, cigarettes, marijuana, and other illicit drugs. African Americans and White non-Hispanics were used as comparison groups. In general, White non-Hispanics and U.S.-born Hispanics had the highest lifetime and past year prevalence rates of substance use. While no statistically significant gender differences were found for any of the racial/ethnic groups, the use of substances among Hispanic girls often exceeded that of their male counterparts. A progressive increase in use of alcohol, cigarettes, marijuana, and other illicit drugs was evident over the two and one-half year duration of the study for both gender groups.

Adolescent↗
PubMed1995

Teacher and parent perceptions of behavior problems among a sample of African American, Hispanic, and non-Hispanic white students.

A multiracial/multiethnic sample of middle school adolescents and their teachers was used to assess whether teacher ratings of student behavior problems varied according to teacher-student racial/ethnic differences and students' perception of teachers' attitudes toward them. No significant mean score differences were found for Hispanic or non-Hispanic white students according to the race/ethnicity of the teachers doing the ratings. However, African American students rated by Hispanic and non-Hispanic white teachers had significantly higher mean total behavior problem scores than African American students rated by African American teachers. Teacher ratings were also compared to those made by parents. The percentage of students rated as cases by teachers but not by parents differed significantly by race/ethnicity of student. Other findings indicated highly significant relationships between student-perceived teacher disparagement and the assignment of high behavior problem scores to students by teachers.

Adolescent↗
PubMed1995

Endothelin-1 decreases glucose, inhibits glucagon, and stimulates insulin release in the rat.

The effects of endothelin-1 (ET-1) infusion at 0, 25, 50, and 75 ng/kg/min on blood glucose, insulin, and ET-1 levels were determined in anesthetized rats. In a separate group of rats, ET-1 was infused at 75 ng/kg/min and glucagon and glucose levels were determined. In another group of rats, the effect on blood glucose of glucagon infusion at 0.2 ng/kg/min with ET-1 infusion at 75 ng/kg/min for 30 minutes was determined. Glucose decreased 10 minutes after initiation of ET-1 infusion at 75 ng/kg/min and at 15 minutes during ET-1 infusion at 25 and 50 ng/kg/min. After 45 minutes, glucose decreased by 1.05 +/- 0.1, 1.44 +/- 0.11, and 1.39 +/- 0.22 mmol/L and ET-1 increased by 4.4 +/- 0.8, 5.2 +/- 1.2, and 11.2 +/- 0.8 pmol/L during ET-1 infusion at 25, 50, and 75 ng/kg/min, respectively. Insulin levels increased during ET-1 infusion of 50 ng/kg/min at 30 and 45 minutes by 300 +/- 75 and 405 +/- 120 pmol/L, respectively. During ET-1 infusion of 75 ng/kg/min, insulin increased at 45 minutes by 570 +/- 180 pmol/L. Glucagon decreased during ET-1 infusion at 15 minutes associated with a decrease in glucose. Glucagon levels subsequently returned to baseline values despite a continued decline in glucose levels. Glucagon infusion at 0.2 microgram/kg/min prevented the early ET-1-induced hypoglycemia. These findings demonstrate that ET-1 decreased blood glucose initially associated with a decrease in glucagon and subsequently associated with enhanced insulin release.

Animals↗
PubMed1995

NG-methyl-L-arginine and somatostatin decrease glucose and insulin and block endothelin-1 (ET-1)-induced insulin release but not ET-1-induced hypoglycemia.

We have previously demonstrated that endothelin-1 (ET-1) increases plasma insulin and decreases blood glucose. The present study was designed to determine if ET-1-induced hypoglycemia occurs in the presence of the insulin secretion inhibitor, somatostatin, and whether ET-1-induced insulin secretion is affected by the nitric oxide synthase I inhibitor, NG-methyl-L-arginine (NMLA), in the anesthetized rat. ET-1 increased plasma insulin and decreased blood glucose in all protocols. Somatostatin alone decreased blood glucose and plasma insulin. Somatostatin blocked ET-1-induced plasma insulin release but did not completely block ET-1-induced hypoglycemia. NMLA alone decreased blood glucose and plasma insulin. NMLA also blocked ET-1-induced insulin release but not ET-1-induced hypoglycemia. The present study confirms our previous finding that ET-1 decreases blood glucose and increases plasma insulin. Because hypoglycemia occurs during insulin inhibition with somatostatin, the present study suggests that ET-1-induced hypoglycemia is partially caused by non-insulin-mediated mechanisms. Because insulin secretion is blocked by nitric oxide synthase I inhibitor, NMLA, the present study suggests that ET-1-induced insulin release may be mediated by production of nitric oxide.

Animals↗
PubMed1995

"Preplacement" of the back of the halo vest in patients undergoing cervical traction for cervical spine injuries: a technical note.

BACKGROUND: In patients with unstable cervical spine injuries initially managed with in-line traction, there is some risk of loss of cervical alignment and of new neurologic deficit when the halo vest is applied. This report outlines a simple technique which facilitates halo application in these patients. METHODS: The back of the halo vest is "prepositioned" before traction is instituted. Once alignment is optimized, halo vest application is easily completed without lifting the patient or discontinuing cervical traction. RESULTS: The authors have used this technique in four patients without complication. CONCLUSIONS: In patients with unstable cervical spine injuries who require an initial period of in-line traction, halo vest application is made easier and safer by "prepositioning" the back of the vest.

Cervical Vertebrae↗
PubMed1995

Analysis of early failures after lumbar decompressive laminectomy for spinal stenosis.

OBJECTIVE: To determine why some patients have no improvement after surgical treatment of lumbar spinal stenosis. DESIGN: We conducted a retrospective study of patients who were referred to our institution between 1990 and 1993 because their symptoms were unchanged or worsened after lumbar decompressive laminectomy. MATERIAL AND METHODS: For the 45 study patients (25 women and 20 men; mean age, 70.8 years), preoperative and postoperative clinical status, preoperative and postoperative imaging studies, and operative reports were analyzed. RESULTS: Preoperatively, only 23 patients (51%) had the clinical syndrome of neurogenic claudication, and 15 (33%) had midline low-back pain without a radicular component. Three other patients had peripheral neuropathy, and three had atypical leg pain. Only 10 patients had radiographic evidence of severe lumbar canal stenosis; the others had moderate, mild, or no stenosis. In 10 patients, surgical decompression was inadequate. Only three patients had the triad of neurogenic claudication, radiographically confirmed severe lumbar stenosis, and adequate decompression of the lumbar canal and lateral recesses. CONCLUSION: The most common pattern in patients with early failure after lumbar laminectomy was the absence of actual neurogenic claudication coupled with the absence of severe stenosis on preoperative imaging studies. The most common technical error was inadequate neural decompression. These data suggest that the outcome may be improved by more careful selection of patients and by performance of an adequate surgical decompression.

Aged↗
PubMed1995

Self-rejection/derogation, peer factors, and alcohol, drug, and cigarette use among a sample of Hispanic, African-American, and white non-Hispanic adolescents.

Data from the first two waves of a longitudinal study are reported on the relationships between self-rejection/derogation and substance use among a multiracial/ethnic sample of adolescents (N = 4,983). Significant increases were found for all three groups between Waves 1 and 2. African-Americans had the lowest rates at both time periods. Peer factors, rejection/derogation, and race/ethnicity were significant predictors of alcohol and cigarette use but not of illicit drug use. Peer factors were more powerful predictors of substance use than rejection/derogation. Interaction analyses indicated peer and rejection/derogation factors were independent predictors of substance use.

Adolescent↗
PubMed1995

Measurement of exercise tolerance on the treadmill in patients with symptomatic lumbar spinal stenosis: a useful indicator of functional status and surgical outcome.

A prospective study of patients with neurogenic claudication and lumbar spinal stenosis was undertaken to determine whether measurement of exercise tolerance on the treadmill would be useful in defining baseline functional status and response to surgical treatment. Twenty patients with an average age of 73 years, all of whom had intractable neurogenic claudication and radiographically confirmed severe lumbar spinal stenosis, were studied. Lumbar decompressive laminectomy was performed in all patients. Preoperatively and 2 months postoperatively, quantitative assessment of ambulation was conducted on a treadmill at 0 degree ramp incline at two different speeds: 1.2 mph and the patient's preferred walking speed. The following information was recorded: time to first symptoms, time to severe symptoms, and nature of symptoms (leg pain, back pain, or generalized fatigue). The examination was stopped after 15 minutes or at the onset of severe symptoms. In the preoperative 1.2-mph trial, the mean time to first symptoms was 2.68 minutes (median 1.31) and the mean time to severe symptoms was 5.47 minutes (median 3.42). In the postoperative trial at the same speed, 13 patients (65%) were able to walk symptom free for 15 minutes. The mean time to first symptoms was 11.12 minutes (median 15) and the mean time to severe symptoms was 11.81 minutes (median 15). Similar findings were recorded in the preferred walking-speed trials. There were no complications from the treadmill testing procedure. These findings indicate that exercise stress testing on a treadmill is a safe, easily administered, and quantifiable means of assessing baseline functional status and outcome following laminectomy in patients with symptomatic lumbar spinal stenosis.

Aged↗
PubMed1994

Endothelin blockade lowers total peripheral resistance in hemorrhagic shock recovery.

To determine whether endothelin (ET) has a role in maintaining circulatory support during hypotensive hemorrhage, we (1) examined cardiac and systemic hemodynamics after a 6-mL hemorrhage in the presence and absence of the ETA receptor blocker BQ-123, (2) examined cardiac and systemic hemodynamics during BQ-123 infusion in nonhemorrhaged rats, (3) measured changes in circulating immunoreactive endothelin (IR-ET) after a 6-mL hemorrhage, and (4) infused pathophysiological doses of ET-1 into rats anesthetized with thiobutabarbital. Twenty minutes after hemorrhage, cardiac output and mean arterial pressure had stabilized in part because of an increase in systemic vascular resistance from 0.86 +/- 0.04 (baseline) to 1.04 +/- 0.05 (20 minutes) mm Hg/mL per minute. The rise in systemic vascular resistance was temporally associated with a significant (24%) increase in circulating IR-ET from 29 +/- 2 to 36 +/- 3 pg/mL 20 minutes after hemorrhage. During BQ-123 infusion mean arterial pressure at 5, 10, and 20 minutes after hemorrhage was 9 +/- 2, 23 +/- 4, and 23 +/- 3 mm Hg lower than values obtained after hemorrhage alone (P < .05). Mean arterial pressure was unaffected by BQ-123 infusion at baseline and 30 minutes after hemorrhage. Systemic vascular resistance was not affected at baseline by BQ-123 infusion. However, systemic vascular resistance was significantly lower 5, 10, 20, and 30 minutes after hemorrhage during BQ-123 infusion compared with hemorrhage alone at each time point. Infusion of BQ-123 into nonhemorrhaged rats had no effect on mean arterial pressure, systemic vascular resistance, or cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Who is Hispanic? Definitions and their consequences.

What is the appropriate method for classifying Spanish-speaking-origin inhabitants of the United States? This paper presents relevant data from the first wave of a longitudinal study of adolescents in the greater Miami area. As expected, the broadest definition--"up to third generation" Hispanic--identified the largest proportion of the sample as Hispanic, whereas parent self-report placed the smallest proportion into the Hispanic category. When policymakers are concerned about enumerating the entire Hispanic population, a definition broader than self-identification should be used; in estimating prevalence rates, however, the use of self-identification may be adequate.

Adolescent↗
PubMed1994

Assessment of bladder function after lumbar decompressive laminectomy for spinal stenosis: a prospective study.

Lumbar spinal stenosis is a common problem in elderly patients. In its more advanced forms, it typically causes intractable leg pain, but many patients also manifest varying degrees of bladder dysfunction. The goal of lumbar decompressive laminectomy is relief of leg pain and paresthesias, yet some patients also achieve improvement in bladder function. This study prospectively investigated patients with lumbar spinal stenosis to determine whether laminectomy had any effect on urological function. Of the 20 patients in the study, 10 were men and 10 women (average age 70.9 years). All patients had severe lumbar stenosis affecting between two and four spinal segments, and all reported some degree of bladder dysfunction. Cystoscopy and urodynamic testing were completed preoperatively. A standard decompressive laminectomy was performed over the appropriate number of spinal segments. Urodynamic studies were repeated at 2 and 6 months postoperatively. At the 6-month follow-up review, bladder function was subjectively improved in 12 patients (60%) and unchanged in eight (40%). Postvoiding residual urine volume was the urodynamic factor most likely to be improved by laminectomy. In nine patients (45%), baseline postvoiding residual urine volume was elevated and all nine had improvement postoperatively. In the remaining 11 patients (55%), this urine volume was normal before and after surgery. Maximum urine flow rates also improved, but the results of cytometrography and electromyography, urine flow pattern, and bladder capacity were unchanged postoperatively. Cystoscopy detected previously undiagnosed malignancy of the lower urinary tract in two patients (10%). It is concluded that lumbar decompressive laminectomy can have a beneficial effect on bladder function in a significant number of patients with advanced lumbar spinal stenosis.

Aged↗
PubMed1994

AIDS-related risk behavior and behavior change in a sexually active, heterosexual sample: a test of three models of prevention.

Because a cure and a vaccine for the human immunodeficiency virus (HIV) are not expected for at least several years, prevention of AIDS is the only means of reducing the spread of the disease. While education, information, and persuasion may be changing the HIV-related attitudes and even behaviors of some individuals, without a theoretical framework, the reasons why some individuals have changed and why other individuals have not changed are elusive. Three social-psychological models that have been applied to health-related behavior--the Health Belief Model (HBM), the Ajzen-Fishbein attitude-behavior model (AFM), and Leventhal et al.'s Self-Regulatory Model (SRM)--are tested in this study. The extent to which each model's variables are related to self-reported behavior change related to HIV and current HIV-related behavior are compared. Results indicate that the SRM and AFM contributed significantly to predicting risk behavior change, and that the HBM and AFM contributed significantly to predicting current risk behavior, after controlling for risk behavior change. Significant predictors of risk behavior change included timeline, identity, and self-efficacy from the SRM; sexual impulse (a barrier) from the HBM; and attitudes about the behaviors from the AFM. Significant predictors of current risk behavior included several barriers from the HBM and negative attitude about risk-reducing behaviors from the AFM.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Prevalence of bulimic behaviors and bulimia among a sample of the general population.

Data are presented on the prevalence of bulimic symptoms and bulimia among a sample of adults residing in north-central Florida (n = 2,075). The data were gathered between 1984 and 1986. The sample included 1,736 whites and 339 blacks, of whom 1,040 were females and 1,035 were males. A current diagnosis of bulimia was made using the criteria of the Diagnostic and Statistical Manual, Third Edition (DSM-III), of the American Psychiatric Association. Females had significantly higher rates than did males on nine of the 10 bulimic symptoms. Blacks had symptom rates equal to or greater than whites on eight of the 10 items, and those in the lowest socioeconomic groups (SES) had rates greater than those in the highest SES group on nine of the 10 symptoms. Eight persons, 0.4% of the total sample, met the DSM-III criteria for a diagnosis of bulimia. These included six white females and two black males. Five of the females were aged 18-29 years; one was over 45. Five of the females were in the lower middle SES group; one was in the upper middle SES group. Both of the black males were aged 30-44, and both were in the lowest SES group. The data emphasize the need to distinguish between bulimic type symptoms and bulimia when estimating the prevalence of eating-related problems in the general population.

Adult↗
PubMed1993

Acculturation and delinquent behavior among Cuban American adolescents: toward an empirical model.

Uses data derived from a study of 6th- and 7th-grade Cuban American adolescents in the greater Miami, Florida, area. The effects of immigrant cultural adjustment on the behavior of adolescents, especially deviant behavior, has been a subject of interest for decades. However, heretofore, little empirical research has been conducted. Key findings indicate that family factors are related to the development of attitudes favoring deviance, whereas acculturation conflicts are associated with delinquent behavior. Results are considered tentative but important for developing a comprehensive and theoretically grounded model of factors contributing to deviant behavior among Hispanic adolescents.

Acculturation↗
PubMed1993

Decision-making orientation and AIDS-related knowledge, attitudes, and behaviors of Hispanic, African-American, and white adolescents.

How adolescents' personal sense of directedness (i.e., peer, parent, or self-directed orientation) affects the decision-making processes of adolescent students regarding AIDS-related knowledge, attitudes, beliefs, behaviors, and skills (KABBS) is examined. The sample consisted of 10th-grade students in 8 public high schools (N = 2,515) in Dade County (greater Miami), Florida. The findings showed that decision-making orientation and directedness was a significant predictor of AIDS-related KABBS of adolescents. Overall, the level of AIDS-related KABBS that were associated with low risk was found significantly more often among self-directed students and least often among peer-directed students. The findings of this study suggest that future preadult health-risk research should incorporate the concept of differences of information processing across adolescents.

Acquired Immunodeficiency Syndrome↗