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Biomedical subjects

L K Brown

Publications and source records attributed to L K Brown.

At least 55 records · Page 3Linked to original sources
PubMed1995

HIV-infected adolescents with hemophilia: adaptation and coping. The Hemophilia Behavioral Intervention Evaluation Project.

OBJECTIVE: It is estimated that 70% of individuals with factor VIII deficiency hemophilia who received blood products before 1985 are infected with human immunodeficiency virus (HIV). The goal of the current study was to assess how adolescents with hemophilia cope with reminders of their HIV status, because adaptation is likely to have implications for these individuals' quality of life and adherence to safer sex recommendations. METHODS: Participants included 297 HIV-positive adolescents with hemophilia who were recruited from 11 sites across the United States. Adolescents reported on the use and effectiveness of strategies for coping with reminders of their HIV status. RESULTS: A significant degree of distress was reported in response to such reminders, with anger being the most commonly reported emotion. Although a wide variety of coping strategies had been tried, participants reported using resignation (80.9%), self-calming (78.8%), and distraction (76.4%) most frequently in their attempts to cope with reminders of HIV. Self-blame (3.6%), engaging in risky behaviors (22.2%), thinking about sex (25.4%), and drug/alcohol use (29.1%) were used least. These adolescents tended to rate more active cognitive and behavioral coping strategies (eg, cognitive restructuring, seeking social support, physical activity) as most effective, whereas passive strategies (eg, wishful thinking, blaming others) were reported to be least helpful. Those individuals who reported being distressed by reminders of HIV endorsed most of the coping strategies significantly more often than the nondistressed group, although ineffective strategies were commonly chosen. Sexually active adolescents were more likely than their abstinent peers to cope by thinking about sex, engaging in risky behaviors, or using alcohol and drugs. CONCLUSION: In this population of adolescents who have known their serostatus for several years, distress about everyday reminders of HIV appears to be associated with ineffective coping strategies.

Adaptation, Psychological↗
PubMed1994

Changing adolescents' HIV-related attitudes and behaviors: the challenge and the opportunity.

Most teenagers have basic knowledge about HIV, although misconceptions about the safety of venipuncture and blood donation persist. By high school age, over half of teens nationally report having had sexual intercourse. Despite adequate knowledge and good intentions to stay safe, which are reinforced by widespread HIV education, consistent condom use by adolescents nationally is sporadic and not increasing. Several projects have achieved behavior change by enhancing teens' personal motivation and assisting in the development of assertiveness and communication skills. Implications for office-based pediatrics are discussed.

Adolescent↗
PubMed1994

Estimated vs actual values for dead space/tidal volume ratios during incremental exercise in patients evaluated for dyspnea.

The physiologic dead space/tidal volume ratio (VD/VT) at rest and during exercise is a sensitive measurement of gas exchange that reflects matching of ventilation to perfusion, but requires an invasive measurement for its calculation. Determining VD/VT noninvasively uses estimations of arterial PCO2 based on the end-tidal PCO2. To further standardize incremental cardiopulmonary exercise testing, we compared actual VD/VT with estimated VD/VT values in 35 patients referred for evaluation of dyspnea. Estimates of VD/VT used the Jones' equation (VD/VT[J]) derived from healthy subjects during steady-state exercise or PETCO2 alone (VD/VT[ET]) to approximate PaCO2. At rest, mean values for VD/VT(J) and actual VD/VT were not different: 0.372 +/- 0.08 vs 0.376 +/- 0.09, p = not significant (NS). Each method identified 61 percent of values > or = to 0.36. In 26 subjects who achieved higher work rates, the mean difference between actual VD/VT and VD/VT(J) increased from 0.009 +/- 0.04 (NS) at low work rate (VO2 = 28.3 percent pred max) to 0.040 +/- 0.06 at high work rate (VO2 = 54.7 percent pred max), p = 0.006. Actual VD/VT identified 18 (69 percent) patients as abnormal vs 13 (50 percent) so identified by VD/VT(J). With exercise, VD/VT(J) was no better than VD/VT(ET). We conclude that during incremental exercise in a patient population, methods for estimating VD/VT progressively underestimate this measurement; and therefore, "normal" estimated VD/VT values may fail to identify underlying pulmonary and/or pulmonary vascular impairment.

Adult↗
PubMed1994

Respiratory dysfunction in Parkinson's disease.

The parkinsonian syndromes include idiopathic Parkinson's disease, parkinsonian syndromes secondary to several known causative agents, and parkinsonian syndromes associated with more widespread CNS lesions and extensive neurologic deficits. They constitute movement disorders with a similar constellation of symptoms: rigidity, tremor, bradykinesia, gait impairment, and postural instability. All of the parkinsonian syndromes are associated with excess morbidity and mortality from respiratory causes, and all can produce the pattern of pulmonary function impairment consistent with neuromuscular disease. In addition, the parkinsonian syndromes can produce upper airway obstruction and abnormalities of ventilatory control, both of which can be life-threatening in those with MSA. The medications used to treat these disorders can also produce respiratory disease. A syndrome of L-dopa-induced respiratory dysfunction has been described, which may be a heterogeneic disorder of choreiform movements of the respiratory muscles, rigidity-akinesis of the respiratory muscles, or abnormal central control of ventilation, all related to the drug. In addition, the ergot-derived dopamine agonists can cause pleural and pulmonary fibrosis.

Ergotamines↗
PubMed1994

Sleep apnea syndromes: overview and diagnostic approach.

The two broad categories of sleep apnea syndrome are associated with obstructive or mixed events on the one hand, and central events on the other. The pathogenesis of both seems to involve periodic reduction in respiratory drive, although obstructive apneas may also involve an anatomic abnormality of the upper airway. Patients with obstructive sleep apnea syndrome most commonly exhibit resuscitative snoring and daytime sleepiness. Snoring is generally less prominent in the central sleep apnea syndromes; those with daytime hypercapnia generally complain of daytime sleepiness, whereas those without hypercapnia complain of disturbed sleep. The overnight polysomnogram is the preferred method of diagnosing both disorders.

Humans↗
PubMed1993

Comparison of AIDS knowledge and HIV-related sexual risk behaviors among adolescents in low and high AIDS prevalence communities.

Data were collected from students attending high school in a rural, low acquired immunodeficiency syndrome (AIDS) prevalence community in Northern California, and compared with students in an inner-city AIDS epicenter (San Francisco). The findings demonstrate that rural adolescents have higher levels of human immunodeficiency virus (HIV) knowledge, especially about risk-reduction strategies. However, rural adolescents also report higher rates of HIV-related sexual risk behaviors. Rural adolescents may not perceive the personal salience of practicing HIV risk-reduction behaviors thus increasing their risk for exposure to sexually-transmitted diseases, including HIV infection. School-based HIV prevention programs developed for rural communities will need to enhance the personal salience of HIV for adolescents' and discourage their discounting of personal risk attributable to a lower prevalence of AIDS in the community. Physicians must become more actively involved in HIV prevention efforts by routinely assessing adolescent patient's sexual behavior and utilizing their clinical interaction to provide HIV education and promote the adoption of HIV risk-reduction behaviors.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Cardiorespiratory responses to incremental exercise in patients with asbestos-related pleural thickening and normal or slightly abnormal lung function.

An increasing number of patients with asbestos exposure are being identified with pleural thickening (PT) alone, with little or no impairment in standard tests of lung function despite their frequent complaint of dyspnea. We have employed incremental cardiorespiratory exercise testing to evaluate the types and mechanisms of impairment in 23 such patients. All had normal lung fields on radiographic examinations and normal (group 1, n = 12) or minimally reduced (group 2A slight restriction, n = 5, group 2B, slight obstruction, n = 6), lung function. Excessive ventilation was common in all groups, but especially in group 2B. Abnormal dead space ventilation (VD/VT) was more frequent in groups 2A (4/5) and 2B (4/6) than in group 1 (3/12). It was associated with O2 desaturation in three patients in groups 2A and B. Cardiovascular abnormalities were rare (1/23). Excessive ventilation and dead space provide a basis for the symptom of dyspnea in these patients.

Adult↗
PubMed1993

Gender differences among adolescent suicide attempters.

When males attempt suicide, they often use more lethal and violent methods than females. However, this article suggests that gender alone is not especially useful in assessing the seriousness of adolescent suicide attempts. In the study discussed here, the sociodemographic and psychological characteristics of female and male suicide attempters seen in a pediatric hospital are compared. There were no sociodemographic differences between the groups. Boys and girls were similar when assessed regarding suicidal ideation, depression, and hopelessness. More males than females were diagnosed with conduct disorders. Some items on the Suicide Intent Scale indicated that boys exhibited more serious intentionality than girls. Division of the sample based on suicide intentionality resulted in differences in the level of reported depression.

Adolescent↗
PubMed1992

Adolescent coping behavior when confronted with a friend with AIDS.

The coping strategies employed by adolescents (n = 871) when presented with a hypothetical situation of a friend with AIDS were examined. Adolescents reported a wide range of imagined responses that were generally adaptive. Girls more than boys and distressed students more than nondistressed students were likely to endorse adaptive coping items. Comparison of the students with a separate sample (n = 472) that responded to a hypothetical situation of a suicidal peer revealed more distress in girls for the AIDS problem and more distress in boys for the suicide problem, contrary to expectations. Adolescents were more distressed and endorsed a wider variety of coping strategies in response to the AIDS scenario than to the suicide problem. Implications for care of adolescents dealing with these significant issues are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Predictors of condom use in sexually active adolescents.

Unprotected sexual intercourse places a substantial number of adolescents at risk for sexually transmitted disease (STD) and human immunodeficiency virus (HIV) infection. While the most effective means of preventing STD/HIV infection among sexually active adolescents is consistent condom use, little is known about the factors that influence their consistent use among adolescents. This study of adolescents (n = 1049, mean age = 16.2 years) found that of the 266 teens who recently became sexually active, only 29% reported using condoms consistently. Consistent condom use was more frequent in males, those with little history of risk behavior and those with stronger intentions to use condoms in the future. Fear and anxiety of HIV, attitudes about risks other than HIV, and other safe behavior intentions were not significantly related to consistent condom use. Although intentions and recent behavior were significantly related, a different group of factors was found to predict intention to use condoms (e.g., perception of condom use by friends, general impulsive attitudes). Identifying and understanding the factors that influence adolescent sexual behavior and intentions is important for developing maximally effective HIV education/prevention programs.

Adolescent↗
PubMed1992

Comparison of human immunodeficiency virus related knowledge, attitudes, intentions, and behaviors among sexually active and abstinent young adolescents.

Although young sexually active adolescents are at greater risk for human immunodeficiency virus (HIV) acquisition than their abstinent peers, little is known about their respective HIV-related knowledge, attitudes, and general risk behaviors. This study of middle school adolescents (n = 1379; mean age, 13.2 years) found that the sexually active boys, compared with their peers, were less knowledgeable about HIV, less fearful of HIV, less tolerant of people with acquired immunodeficiency syndrome (AIDS), riskier in non-HIV-related attitudes and had a greater history of other risk behavior. A similar, but less marked pattern, was found for girls. It is suggested that physicians counsel all adolescents about HIV and sexuality during office visits and that early adolescent sexuality should prompt special efforts in HIV education/counseling.

Adolescent↗
PubMed1992

Pneumothorax due to ball-valve obstruction of an endotracheal tube in a mechanically ventilated patient.

Barotrauma is a well-known complication of mechanical ventilation, thought to be related to alveolar rupture from localized hyperinflation. Mishaps related to endotracheal intubation can lead to barotrauma such as inadvertent intubation of the right mainstem bronchus. In this report, we describe pneumothorax as a consequence of ball-valve occlusion, a previously undescribed endotracheal tube malfunction.

Airway Obstruction↗
PubMed1992

Positive Kveim test in patients with coexisting sarcoidosis and human immunodeficiency virus infection.

We present two cases of sarcoidosis complicated by HIV infection. Each case had a different level of sarcoidosis activity and coexisted with either an AIDS-related infection or a HIV-positive state. Manifestations of sarcoidosis were not apparent in the patient with the AIDS-defining opportunistic infection, but were active in the patient with asymptomatic HIV infection. Both patients had granulomatous reactions to Kveim antigen, and one had such a reaction following an AIDS-defining infection. These findings suggest that non-T-cell mechanisms may be involved in granuloma formation in sarcoidosis.

Adult↗
PubMed1991

The correlates of planning in adolescent suicide attempts.

Adolescent suicide attempts are often impulsive. It has been suggested that individuals who make nonimpulsive (premeditated) attempts have greater suicidal intent and are more hopeless than the impulsive attempters. Eighty-six adolescent suicide attempters were categorized according to the degree of premeditation of their attempt, as measured by two items of the Suicide Intent Scale. Sex, age, method of attempt, and the number of prior attempts were not useful discriminators between these groups. The nonimpulsive attempters were significantly more depressed and more hopeless than the impulsive attempters, as measured by several standardized scales. Measures of depression, hopelessness, and suicidal ideation were highly correlated in both groups. Anger turned inward and hopelessness were strongly correlated only in the premeditated group, suggesting that the nonimpulsive attempter's distress may bear a strong relationship to self anger.

Adolescent↗
PubMed1991

AIDS education: the Rhode Island experience.

AIDS prevention, by public school education, is designed to change knowledge, attitudes, and future behavior. This study evaluated the impact of a state-mandated educational program on a sample of 2709 adolescents. Changes from pre to posttest were evaluated using standardized change scores and comparisons between the experimental and a delayed education control group were made. The experimental group, but not the control group, changed to a statistically significant degree (p less than .001). They became more knowledgeable, endorsed slightly more tolerant attitudes, and reported an increased intention to avoid intercourse as a means of AIDS prevention. The extent of change was substantially greater for knowledge than for attitudes. Age, gender, and AIDS-related anxiety were found to be significant variables in the AIDS education process. The modest changes observed emphasize that the dissemination of AIDS information by public schools is only the first step in changing adolescent behavior as a means to AIDS prevention and that other, additional approaches are needed.

Acquired Immunodeficiency Syndrome↗