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Biomedical subjects

L K Brown

Publications and source records attributed to L K Brown.

At least 37 records · Page 2Linked to original sources
PubMed1998

HIV-related attitudes and risk behavior of young adolescent mothers.

This article reports on the prevalence of HIV-related risk behaviors among young adolescent mothers. To determine the facilitators and barriers to condom use for young adolescent mothers, a survey of HIV-related knowledge, attitudes and behavior and focus groups was conducted. Young mothers (N = 58) have basic knowledge and some personal concern about HIV, but also hold common misconceptions about HIV and people with AIDS. Despite their anxiety about HIV, almost half rarely or never protect themselves against HIV by using a condom. Although 70% of the sample use hormonal contraceptives, more than one third of the sample have had a second child within an average of 18 months after the birth of their first baby. Personal concern about HIV was significantly associated with consistency of condom use. Because of low rates of condom use and substantial rates of multiple sex partners, STDs and second pregnancies, disadvantaged adolescent mothers are at risk of exposure to HIV. Increased personalized concern for HIV may lead to greater motivations for safer behavior for these mothers. In addition to protecting their own safety, the protection of their child may be an important motivator for safe behavior. Cultural taboos against safe sex and the perception of such behavior as "unfeminine" also need to be addressed for these women.

Adolescent↗
PubMed1997

Publications in subspecialty journals on end-of-life ethics.

BACKGROUND: Factors that impede patient adoption of advance directives and inhibit physician-patient discussions about end-of-life issues remain incompletely defined. Determination of publication rates of articles on end-of-life ethics in different subspecialty journals may provide insight into physicians' reluctance to promote advance directives for their patients, which appears to vary between subspecialty fields. OBJECTIVE: To determine publication rates of items on end-of-life issues and other ethics topics. METHODS: We surveyed core journals from 1976 to 1995 in cardiology (n = 5), critical care medicine (n = 1), nephrology (n = 4), oncology (n = 7), and pulmonary medicine (n = 2). RESULTS: Critical care medicine (50.4%; 95% confidence interval [CI], 45.0%-55.8%) and pulmonary medicine (27.6%; 95% CI, 22.7%-32.5%) journals published considerably more articles on end-of-life issues than journals in cardiology (4.1%; 95% CI, 0.8%-7.4%), nephrology (11.0%; 95% CI, 7.9%-14.1%), or oncology (6.9%; 95% CI, 1.5%-12.3%). Oncology (30.7%; 95% CI, 25.3%-36.1%), critical care medicine (29.6%; 95% CI, 24.2%-35.0%), and pulmonary medicine (21.5%; 95% CI, 16.6%-26.4%) journals published more items pertaining to all ethics-related topics compared with cardiology (11.0%; 95% CI, 7.3%-14.7%) or nephrology (7.3%; 95% CI, 4.2%-10.4%) journals. Oncology journal ethics articles most often pertained to informed consent or research issues. CONCLUSIONS: Different internal medicine subspecialty fields demonstrate markedly different patterns of publishing items on topics pertaining to end-of-life issues.

Editorial Policies↗
PubMed1997

Adolescents with psychiatric disorders and the risk of HIV.

OBJECTIVE: To review literature relevant to human immunodeficiency virus (HIV)-associated risk behaviors among adolescents with psychiatric disorders and psychological influences on risk behaviors. METHOD: This report is based on review of 66 articles, which comprise all of the relevant literature in the English language. RESULTS: Although the seroprevalence of HIV in adolescents with psychiatric disorders is unknown, studies indicate that adolescents with psychiatric disorders are at greater risk than their peers because of increased rates of unsafe sexual practices, impulsivity, self-destructive attitudes, cognitive immaturity, high rates of substance use, self-cutting behavior, and the sequelae of sexual abuse. CONCLUSION: Directions are proposed for the design of developmentally appropriate, clinically oriented HIV prevention interventions based on the relationships between psychological dysfunction, social stressors, and HIV risk behaviors.

Adolescent↗
PubMed1997

Influence of sexual abuse on HIV-related attitudes and behaviors in adolescent psychiatric inpatients.

OBJECTIVE: To investigate the associations between sexual abuse and human immunodeficiency virus (HIV)-related attitudes and behaviors of adolescents with a psychiatric disorder. METHOD: HIV-related knowledge, attitudes, and behaviors were examined by self-report assessment of adolescents admitted to a psychiatric hospital (N = 100). A subsample (n = 30) completed a role-playing exercise regarding HIV-preventive behavior that was scored for the degree of effective communication by raters blind to the subjects' abuse history. RESULTS: HIV-related risk behaviors were prevalent, including unprotected sexual intercourse (67%) and multiple partners (27%) among the sexually active (71% of the total). Also frequent were alcohol and drug use (25%) and sharing cutting instruments (22%) among those engaged in self-cutting behavior (62%). The 38% of the sample identified as having a history of sexual abuse indicated significantly poorer self-efficacy concerning condom use than their peers. Abused females scored significantly lower on the self-efficacy of condom use scale and reported significantly more frequent alcohol use than nonabused females (p = .003). A hierarchical multiple regression that controlled for consistency of condom use and tolerance of people with acquired immunodeficiency syndrome found that abuse history uniquely accounted for 16% of the variance in condom use self-efficacy. Analysis of the videotaped role-play found that abused adolescents were significantly less competent and had more difficulty in effective communication than their peers (p = .003). CONCLUSION: A history of sexual abuse is associated with impaired safe sexual decision-making and HIV-preventive communication skills, even in this already at-risk group. This study also underscores the importance of actively addressing these issues in the context of clinical care.

Adolescent↗
PubMed1997

Pulmonary involvement in Fabry disease.

Fabry disease is an X-linked inborn error of metabolism resulting from deficient activity of alpha-galactosidase A. Although several case reports have suggested an association between Fabry disease and airway obstruction, this has not been investigated in a large series of patients. We studied 25 unselected, consecutive, enzymatically diagnosed men referred to a General Clinical Research Center for evaluation. Thirty-six percent complained of dyspnea, and 24% had cough and/or wheezing. Symptoms were similar in smokers and nonsmokers. Nine (36%) had airway obstruction on spirometry; this finding was associated with age > or = 26 yr (p < 0.05) and dyspnea or wheezing (p < 0.005), but only weakly with smoking (p = 0.062). Five of eight patients responded to bronchodilators, but all 10 methacholine challenges were negative. Chest radiographs revealed normal lung fields in 24 patients and streaky bibasilar densities in one. No pulmonary uptake occurred on 67Ga citrate scans (18 patients) and 111In-tagged leukocyte scans (16 patients). Specific alpha-galactosidase A mutations were identified in 17 patients; all three patients with frameshift mutations and both subjects with the D264V missense mutation had obstructive impairment. We conclude that airway obstruction commonly occurs in patients with Fabry disease regardless of smoking history, and it increases with age. The presence of obstruction may be associated with certain mutations and most likely results from fixed narrowing of the airways by accumulated glycosphingolipid.

Adolescent↗
PubMed1997

A pilot HIV prevention program for adolescents in a psychiatric hospital.

In a pilot HIV prevention program for 35 adolescents in a psychiatric hospital, patients completed assessments of their HIV-related knowledge, attitudes, and behaviors before entering the program, at discharge, and three months after discharge. At discharge they showed significant increases in knowledge, tolerance of people with AIDS, and self-efficacy (or perceived ability to engage in safe-sex behaviors), although those who had been sexually abused showed significantly less change in self-efficacy than others. At three-month follow-up, scores had returned to baseline, but there was a trend toward increased condom use. Findings confirm the need for HIV-AIDS interventions for adolescents in psychiatric settings despite barriers to implementation.

Adolescent↗
PubMed1997

Diagnostic value of tests that discriminate between exudative and transudative pleural effusions. Primary Study Investigators.

STUDY OBJECTIVE: To (1) determine appropriate decision thresholds and diagnostic accuracies for pleural fluid (PF) tests that discriminate between exudative and transudative pleural effusions, and (2) evaluate the quality of the primary investigations. DESIGN: Formal meta-analysis of studies that report the diagnostic value of pleural fluid tests. SETTING: Data collected from international academic medical centers. PATIENTS: Hospitalized patients undergoing thoracentesis for pleural effusions. INTERVENTIONS: Primary investigators were requested to transmit original data from patients described in their studies. MEASUREMENTS AND RESULTS: Eight primary studies described 1,448 patients with one or more of the following tests: protein (P)-PF, P-PF/serum ratio (R), bilirubin (BILI)-R, lactate dehydrogenase (LDH)-PF, LDH-R, cholesterol (C)-PF, C-R, and albumin gradient. We found that all eight tests had similar diagnostic accuracies when evaluated by receiver operating characteristic (ROC) analysis except for BILI-R, which was less diagnostically accurate. Decision thresholds determined by ROC analysis differed from previously reported values for LDH-PF (>0.45 upper limits of normal) and C-PF (>45 mg/dL). Paired and triplet test combinations tended to have higher diagnostic accuracies compared with individual tests, but examination of the odds ratios with 95% confidence intervals did not identify a clearly superior test combination. Limitations of the primary studies presented a high likelihood of bias affecting their results. CONCLUSIONS: Several strategies exist for clinicians in utilizing PF tests to classify effusions as exudates or transudates but accurate interpretations of these test results will require better designed studies.

Albumins↗
PubMed1996

The accuracy of late antenatal screening cultures in predicting genital group B streptococcal colonization at delivery.

OBJECTIVE: To determine the accuracy of late antenatal anogenital cultures in predicting group B streptococcal colonization at delivery. METHODS: Swabs of the vagina and rectum were obtained from 826 women during routine prenatal visits at approximately 35-36 weeks' estimated gestation. The same women were recultured at admission for delivery. Swabs were cultured in broth media. Test performance indices were calculated using culture status at the time of delivery as the reference. Based on the sensitivity and specificity of antenatal cultures derived from analysis of this study population, we estimated predictive values of late antenatal cultures for a range of group B streptococcal carriage rates. RESULTS: Group B streptococci were identified in specimens from 219 of 826 women (26.5%). The sensitivity of late antenatal cultures for identifying colonization status at delivery was 87% (95% confidence interval [95% CI] 83-92). Specificity was 96% (95% CI 95-98). Positive predictive value was 87% (95% CI 83-92), and negative predictive value was 96% (95% CI 95-98). Test performance was similar from 1-5 weeks before delivery, but declined when 6 or more weeks had elapsed between the antenatal culture and delivery. Among patients cultured 6 or more weeks before delivery, sensitivity was only 43%, specificity 85%, and positive and negative predictive values were 50 and 81%, respectively. We estimated positive and negative predictive values of 85 and 97% for a colonization rate of 20%, and 79 and 98% for a colonization rate of 15%. CONCLUSION: Anogenital cultures in broth media obtained during the late antenatal period are accurate in predicting group B streptococcal colonization status at delivery in term parturients, and they perform significantly (P < .01) better than cultures collected 6 or more weeks before delivery.

Adult↗
PubMed1996

Doppler sonography in the evaluation of corporovenous competence after penile vein ligation surgery.

Doppler ultrasonographic findings in patients after penile vein ligation surgery are described and compared to the results of cavernosometry and cavernosography. Peak systolic and end diastolic velocities were recorded for both cavernosal arteries at 5 min intervals after papaverine injection for a total of 30 min. Peak end diastolic flow rates were compared with cavernosometric and cavernosographic results at 0-10 min, 11-20 min, and 21-30 min. Cavernosography identified venous leakage in nine patients. The end diastolic velocities were greater than the 5 cm/s threshold level generally considered to be indicative of venous leakage in nine of the nine patients (100%) at 0-10 min, in eight of the nine (89%) at 11-20 min, and in nine of the nine (100%) at 21-30 min. Although peak end diastolic velocities at or near the 5 cm/s threshold could be found in patients both with and without recurrent venous leakage in the initial 10 min of the studies, only patients with recurrent venous leakage had diastolic velocities that exceeded the 5 cm/s level when measured 10 min or more after injection. Measurement of end diastolic velocities between 21 and 30 min after injection seemed to discriminate most effectively the patients with recurrent venous leakage from those without leakage in the postoperative population.

Adult↗
PubMed1995

Forced midexpiratory time: reference values and the effect of cigarette smoking.

BACKGROUND: Forced midexpiratory time (FET25-75%), the time required to exhale from 25 to 75% of forced vital capacity (FVC), has been advocated as a relatively volume-independent measure of obstruction. Previous estimates of normal FET25-75% have not systematically studied the effect of age, height, sex, and smoking history. METHODS: We analyzed flow-volume loops from 369 normal lifetime nonsmokers and smokers, a random sample of the population of Michigan. Linear models including age and/or height were considered, with and without logarithmic transformation. RESULTS: The best models used age, or age and height, and no transformation. Age and height contributed much less to the variability of FET25-75% than to spirometric flows previously investigated. The largest r2 was found in the male smokers, with the largest contribution from age, suggesting a smoking effect. CONCLUSIONS: As age was the major contributor to the value of FET25-75% and that contribution was small, we suggest the use of simplified age-stratified reference values derived from our data.

Adult↗
PubMed1995

School-based AIDS education for adolescents.

PURPOSE: To describe a program which utilizes medical students and persons with AIDS (PWAs) to provide for adolescents school-based education about acquired immunodeficiency syndrome (AIDS). METHODS: Two 1.5 hour classroom sessions were conducted by medical students and persons with AIDS for seventh and eighth grade students (n = 1,161 students) at two urban middle schools. In addition, a two hour informational session was provided for parents. A 49 question student health survey was used to evaluate adolescents' HIV knowledge, tolerance of persons with AIDS, and intentions to engage in human immunodeficiency virus (HIV) safe behaviors. RESULTS: Significant (p < 0.01) increases in HIV knowledge and tolerance of persons with AIDS were observed, which persisted for three months. A significant (p < 0.01) improvement in intention to engage in HIV-safe behaviors was observed but did not persist for three months. CONCLUSIONS: Medical students and persons with AIDS can provide school-based AIDS education to early adolescents.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Pleural fluid chemical analysis in parapneumonic effusions. A meta-analysis.

Controversy exists regarding the clinical utility of pleural fluid pH, lactate dehydrogenase (LDH), and glucose for identifying complicated parapneumonic effusions that require drainage. In this report, we performed a meta-analysis of pertinent studies, using receiver operating characteristic (ROC) techniques, to assess the diagnostic accuracy of these tests, to determine appropriate decision thresholds, and to evaluate the quality of the primary studies. Seven primary studies reporting values for pleural fluid pH (n = 251), LDH (n = 114), or glucose (n = 135) in pneumonia patients were identified. We found that pleural fluid pH had the highest diagnostic accuracy for all patients with parapneumonic effusions as measured by the area under the ROC curve (AUC = 0.92) compared with pleural fluid glucose (AUC = 0.84) or LDH (AUC = 0.82). After excluding patients with purulent effusions, pH (AUC = 0.89) retained the highest diagnostic accuracy. Pleural fluid pH decision thresholds varied between 7.21 and 7.29 depending on cost-prevalence considerations. The quality of the primary studies was the major limitation in determining the value of pleural fluid chemical analysis. We conclude that meta-analysis of the available data refines the application of pleural fluid chemical analysis but a clearer understanding of the usefulness of these tests awaits more rigorous primary investigations.

Chest Tubes↗
PubMed1995

Prospective validation of an acute respiratory distress syndrome predictive score.

We derived an Acute Respiratory Distress Syndrome Score (ARDS Score) from previously described training set data. To validate its diagnostic accuracy for identifying a complicated course (early death or prolonged intubation) in acute lung injury, 50 patients were prospectively scored using an ARDS Score decision threshold of > or = 2.5 to discriminate between an uncomplicated (successful extubation after < or = 14 d) and complicated course. Predictor factors incorporated in the ARDS Score were collected on Day 4 and Day 7 of ARDS and included PaO2/PAO2 ratio, required positive end-expiratory pressure (PEEP), and chest radiograph progression. The diagnostic accuracy of the ARDS Score for determining a complicated course as well as overall survival was compared with three other available indices. Using receiver operating characteristic (ROC) analysis, the ARDS Score and Lung Injury Score (LIS) had the greatest diagnostic accuracy for determining a complicated course, but the Simplified Acute Physiology Score (SAPS Score) (score > or = 14) more accurately identified survival. The LIS components of static respiratory system compliance (Crs) and chest radiograph description did not differ between patient groups. The interobserver concordance of the dynamic chest radiograph interpretation included in the ARDS Score was significant (p < 0.05). We conclude that the previously derived ARDS Score has valid diagnostic accuracy for identifying patients with ARDS who will follow a complicated course.

Acute Disease↗
PubMed1995

Cardiorespiratory responses to incremental exercise in sarcoidosis patients with normal spirometry.

Patients with sarcoidosis are known to have histologic pulmonary abnormalities despite normal lung fields or conventional pulmonary function or both. These patients permit a useful assessment of the alleged greater sensitivity of the various measurements made during incremental cardiorespiratory exercise testing. Abnormal responses on such testing may provide insight into such complaints as dyspnea in these patients. Incremental exercise testing was performed on 30 patients with biopsy-proven sarcoidosis who had normal spirometry; 13 had clear lung fields radiographically. Of these patients, the 21 who had normal single-breath diffusing capacity for carbon monoxide (Dsb; [group A]) were compared with the 9 who had decreased Dsb (group B). Half of the group A patients had excessive ventilation and 38% had increased dead space to tidal volume ratio (Vd/Vt), but frequencies of these abnormalities were greater in group B, 89 and 78%, respectively. Ventilatory response, as minute ventilation to oxygen consumption ratios ventilatory equivalents, and deadspace to tidal volume ratio (Vd/Vt) ratios were higher in group B. Widened alveolar-arterial oxygen pressure differences were seen in 7 of 9 group B patients but only 1 of 17 group A patients. This study supports the clinical impression that occult pulmonary impairment may be present in patients (in this case, sarcoidosis patients) with normal pulmonary function, and corroborates the utility of exercise testing in demonstrating such impairment. Reduction in Dsb predicted greater frequency of abnormal exercise responses, especially in oxygenation.

Adult↗