Biomedical subjects

R J Adams

Publications and source records attributed to R J Adams.

At least 37 records · Page 2Linked to original sources

PubMed2001

Stroke prevention in sickle cell disease (STOP) study guidelines for transcranial Doppler testing.

The Stroke Prevention in Sickle Cell Disease (STOP) trial used transcranial Doppler (TCD) to screen children with sickle cell disease with no history of stroke. Children (who consented) who had time-averaged mean of the maximum (TAMM) velocities in the middle cerebral artery and/or distal internal carotid artery were randomized to transfusion or standard. Over a slightly more than 20-month average follow-up, there were 11 strokes in the standard care arm and 1 stroke in the transfusion arm. This study has caused a great deal of interest in using TCD to screen children with sickle cell disease. For the STOP TCD data to be applied appropriately, it is necessary for users of TCD to understand how the STOP TCD examinations were performed, how the TCD velocities were measured, and which velocities were used. This article will review the STOP TCD scanning protocol and the reading protocol and review the TAMM velocity and how it differs from other velocity measurements.

Adolescent↗

PubMed2001

Patient preferences for autonomy in decision making in asthma management.

BACKGROUND: Lower patient preferences for autonomy in management decision making during asthma exacerbations have been associated with an increased risk for future hospital admissions. We sought to examine patient preferences for asthma self-management autonomy, and the clinical and psychosocial factors associated with autonomy preferences. METHODS: A cross sectional observational study was performed with data collected between June 1995 and December 1997 of 212 adult patients with moderate to severe asthma managed, at least in part, at two teaching hospitals. Subjects completed a survey of autonomy preferences, quality of life, clinical morbidity and health service use, asthma knowledge, self-efficacy, coping styles, and psychosocial measures. RESULTS: Patients preferred clinicians to assume the major role in most decision making about their management. However, patients wished to remain in control in choosing when to seek care and wanted to share decisions regarding initiating changes in medications during a moderate exacerbation. Multiple regression analysis showed that concerns about adverse effects of medications, education level, an active coping style, perceptions of the propensity of physicians to involve them in treatment decision making, and concerns about costs causing delays in seeking medical care were associated with preferences for autonomy in decision making. Autonomy preferences were not related to measures of concurrent clinical asthma control or health related quality of life. CONCLUSIONS: In a group of patients with moderate to severe asthma, a high proportion of whom were from socioeconomically disadvantaged backgrounds, education level, perceived physician behaviour, cost barriers to care, and psychosocial factors (but not clinical asthma control or management) were related to patient preferences for autonomy in management decision making during asthma exacerbations. This has implications for asthma action plans and design of self-management programmes.

Adaptation, Psychological↗

PubMed2001

Sickle cell and the brain.

Sickle cell disease affects many organ systems, but one of the major morbidities is brain disease, especially stroke. In this paper, the etiology, diagnosis, treatment, and prevention of clinical stroke, as well as so-called "silent stroke," are examined. Risk factors, diagnostic tools, and data from prevention and treatment studies as well as issues pertaining to neuropsychological function, especially in younger patients, are discussed and current best options for treatment considered.

Age Factors↗

PubMed2001

Impact of inhaled antiinflammatory therapy on hospitalization and emergency department visits for children with asthma.

OBJECTIVE: Although the efficacy of inhaled antiinflammatory therapy in improving symptoms and lung function in childhood asthma has been shown in clinical trials, the effectiveness of these medications in real-world practice settings in reducing acute health care use has not been well-evaluated. This study examined the effect of inhaled antiinflammatory therapy on hospitalizations and emergency department (ED) visits by children for asthma. DESIGN: Defined population cohort study over 1 year. Setting. Three managed care organizations (MCOs) in Seattle, Boston, and Chicago participating in the Pediatric Asthma Care-Patient Outcome Research and Treatment II trial. Participants. All 11 195 children, between 3 to 15 years old, with a diagnosis of asthma who were enrolled in the 3 MCOs between July 1996 and June 1997. OUTCOME MEASURES: We identified children with 1 or more asthma diagnoses using automated encounter data. Medication dispensings were identified from automated pharmacy data. Multivariate logistic regression analysis was used to calculate effects of inhaled antiinflammatory therapy on the adjusted relative risk (RR) for hospitalization and ED visits for asthma. RESULTS: Over 12 months, 217 (1.9%) of children had an asthma hospitalization, and 757 (6.8%) had an ED visit. After adjustment for age, gender, MCO, and reliever dispensing, compared with children who did not receive controllers, the adjusted RRs for an ED visit were: children with any (>/=1) dispensing of cromolyn, 0.4 (95% confidence interval [CI]: 0.3, 0.5); any inhaled corticosteroid (ICS), 0.5 (95% CI: 0.4, 0.6); any cromolyn or ICS combined (any controller), 0.4 (95% CI: 0.3, 0.5). For hospitalization, the adjusted RR for cromolyn was 0.6 (95% CI: 0.4, 0.9), for ICS 0.4 (95% CI: 0.3, 0.7), and for any controller 0.4 (95% CI: 0.3, 0.6). A significant protective effect for both events was seen among children with 1 to 5 and with >5 antiinflammatory dispensings. When the analysis was stratified by frequency of reliever dispensing, there was a significant protective effect for controllers on ED visits for children with 1 to 5 and with >5 reliever dispensings and on the risk of hospitalization for children with >5 reliever dispensings. CONCLUSIONS: Inhaled antiinflammatory therapy is associated with a significant protective effect on the risk for hospitalization and ED visits in children with asthma. Cromolyn and ICSs were associated with similar effects on risks.asthma drug therapy, inhaled antiinflammatory agents, health maintenance organizations, hospitalization, emergency department.

Administration, Inhalation↗

PubMed2001

Rallicola deckeri n. sp. (Phthiraptera: Philopteridae) from Ruddy Woodcreepers Dendrocincla homochroa (Passeriformes: Furnariidae) collected in Campeche, Mexico.

A new species of Rallicola Johnston and Harrison (Phthiraptera: Philopteridae) is described from lice collected from a series of Ruddy Woodcreepers Dendrocincla homochroa (Aves: Dendrocolaptinae) in Campeche, Mexico. Rallicola deckeri is easily recognized by the unique shape of the mesosome in the male and by the pattern of divided sternites on the female.

Animals↗

PubMed2001

Molecular systematics of Goniodidae (Insecta: Phthiraptera).

The higher level phylogenetic relationships within the avian feather lice (Insecta: Phthiraptera: Ischnocera) are extremely problematic. Here we investigate the relationships of 1 family (Goniodidae), sometimes recognized as distinct within Ischnocera, using parsimony and likelihood analyses of nuclear and mitochondrial DNA sequences. These data support monophyly for a restricted definition of traditional Goniodidae, but recognition of this family would result in paraphyly of the large heterogeneous family Philopteridae. We show that the New World Chelopistes is not related to other members of Goniodidae, despite similarities in morphology, but rather is the sister taxon to Oxylipeurus. Within Goniodidae, genera are divided into those occurring on Galliformes (the Goniodes complex) and those occurring on Columbiformes (the Coloceras complex). Within the well-sampled Coloceras complex, or Physconelloidinae, several groups are identified. However, traditionally recognized genera such as Coloceras and Phvsconelloides appear to be paraphyletic. Whereas the phylogeny of Goniodidae reflects some aspects of host relationships, biogeography also influences coevolutionary history.

Animals↗

PubMed2000

Transcranial Doppler (TCD) screening for stroke prevention in sickle cell anemia: pitfalls in technique variation.

BACKGROUND: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) identified children as being at high stroke risk if the time-averaged maximum mean velocity (TAMMV) of the middle cerebral or intracranial internal carotid arteries measured > or = 200 cm/s. These values were obtained utilizing a 2-mHz dedicated nonimaging pulsed Doppler technique (TCD) and manual measurements. Questions have been raised as to the comparability of results obtained with different ultrasound machines and measurement techniques. OBJECTIVE: The purpose of this study was to compare nonimaging (TCD) and transcranial duplex imaging (TCDI) findings in children potentially at risk for stroke with sickle cell disease. MATERIALS AND METHODS: Twenty-two children with sickle cell disease and no history of stroke were evaluated by both TCD and TCDI. Examinations were performed on the same day without knowledge of the other modality results and read independently using manually obtained measurements. Mean velocities, peak systolic velocities, and end diastolic velocities obtained by the two techniques were compared. In a subgroup, manual measurements were compared to electronically obtained measurements. RESULTS: TCDI values were lower than TCD measurements for all vessels. TCDI TAMMV values were most similar to the TCD values in the middle cerebral artery (-9.0%) and distal internal cerebral artery (-10.8%), with greater variability in the anterior cerebral artery (-19.3%), bifurcation (-16.3%), and basilar arteries (-23.1%). Risk group placement based on middle cerebral artery TAMMV values did not change when comparing the two techniques. Measurements obtained electronically were lower than those obtained manually. CONCLUSION: Velocities obtained by TCDI may be lower than TCD measurements, and these differences should be taken into consideration when performing screening for stroke risk and selection for prophylactic transfusion based on the STOP protocol.

Adolescent↗

PubMed2000

The predictive utility of the Teller acuity cards for assessing visual outcome in children with preterm birth and associated perinatal risks.

We assessed binocular grating visual acuity with the Teller acuity cards (TAC) in 3-36-month-olds at risk for visual disorders. After 3-8 years, each child was assessed with the TAC and with a battery of tests of spatial and non-spatial vision. The initial TAC score: (1) was uncorrelated with any of the later measures; (2) had low positive, but high negative predictive value for the later tests; (3) had low sensitivity, but high specificity for identifying children with and without visual disorders, respectively. We concluded that early TAC grating acuity predicts visual outcome, but perhaps only for children with initially normal grating acuity.

Child↗

PubMed2000

Successful DNA immunization against measles: neutralizing antibody against either the hemagglutinin or fusion glycoprotein protects rhesus macaques without evidence of atypical measles.

Measles remains a principal cause of worldwide mortality, in part because young infants cannot be immunized effectively. Development of new vaccines has been hindered by previous experience with a formalin-inactivated vaccine that predisposed to a severe form of disease (atypical measles). Here we have developed and tested potential DNA vaccines for immunogenicity, efficacy and safety in a rhesus macaque model of measles. DNA protected from challenge with wild-type measles virus. Protection correlated with levels of neutralizing antibody and not with cytotoxic T lymphocyte activity. There was no evidence in any group, including those receiving hemagglutinin-encoding DNA alone, of 'priming' for atypical measles.

Animals↗

PubMed2000

Retest variability of human infant contrast sensitivity: how many tests are sufficient?

Retest variability of a new infant contrast sensitivity (CS) card procedure was assessed by binocular measurement of a group of 20 6-month-olds twice within a 1-week period. Coefficient of reliability analyses showed that within-subject variability between tests was only slightly less than variation across subjects, which suggests that results from a single test are a poor predictor of an infant's "true" visual functioning. To determine how many tests are needed to estimate when infant CS stabilizes to within an acceptable (0.15 log unit) criterion, a second experiment was conducted in which a small group of subjects was tested repeatedly over a 2-week period. The results showed that averaging performance on 2 to 3 tests was required before an accurate estimate of the subject's performance could be obtained. Our results suggest that caution should be taken in the interpretation of a single measurement of infant visual functioning.

Contrast Sensitivity↗

PubMed2000

Stroke prevention in sickle cell disease.

Neurological complications, especially stroke, have long been recognized in sickle cell disease. Advances in care have increased the life expectancy of such patients, and recent information has better established the epidemiology of stroke. Prevention of stroke in children has been established in a clinical trial. Silent brain lesions revealed by MRI are common and are associated with impairments of cognitive function. Transfusion remains the primary mode of prevention and treatment for stroke, although interest is increasing in hydroxyurea; however, there are no data regarding its efficacy.

Adolescent↗

PubMed2000

Factors associated with hospital admissions and repeat emergency department visits for adults with asthma.

BACKGROUND: A small proportion of patients with asthma account for a disproportionate number of acute health service events. To identify whether factors other than severity and low socioeconomic status were associated with this disproportionate use, a prospective study was undertaken to examine management and psychosocial factors associated with increased risk for admission to hospital with asthma and repeat visits to the emergency department over a 12 month period. METHODS: A total of 293 patients with moderate or severe asthma managed at least in part at two teaching hospitals completed surveys of clinical status, acute events, sociodemographic, and psychological variables. RESULTS: Twenty three percent had a single admission to hospital and 16% had two or more hospital admissions. Twenty six percent had one emergency department visit and 32% had two or more visits to the emergency department. In a multiple logistic regression model, adjusted for age, sex, education and income, odds ratios (95% CI) for baseline factors associated with hospital admissions over the next 12 months were: moderate severity compared with severe asthma 0.6 (0.2 to 0.9); no hospital admissions in the past 12 months 0.1 (0.01 to 0.2); not possessing a written asthma action plan 4.0 (1.5 to 10.7); less use of an avoidance coping style 0.4 (0.3 to 0.7); lower preferences for autonomy in asthma management decisions 1.4 (0.96 to 2.0). Adjusted odds ratios (95% CI) for repeat emergency department visits were: moderate asthma severity 0.3 (0.1 to 0.8); current regular use of oral corticosteroids 10.0 (3.1 to 32.4); a hospital admission in the past 12 months 2.9 (1.8 to 4.8); not possessing a written asthma action plan 2.2 (1.1 to 5.6); less dislike of asthma medications 0.7 (0.5 to 0.9). CONCLUSIONS: In addition to factors relating to severity, not possessing a written asthma action plan, avoidance coping, and attitudes to self-management were related to acute use of health services in this at risk group. Interventions need to address or take these factors into account to reduce asthma morbidity.

Adolescent↗

PubMed2000

Lessons from the Stroke Prevention Trial in Sickle Cell Anemia (STOP) study.

Stroke is generally uncommon in children, but sickle cell disease is associated with a high risk of stroke in the early years of childhood. Large cerebral arteries, especially the middle cerebral and intracranial internal carotid, develop stenosis that predisposes to ischemic stroke. Noninvasive prediction of risk using transcranial Doppler ultrasonography made it possible to test primary stroke prevention in a clinical trial comparing chronic blood transfusion with standard care. A consortium of 14 clinical centers conducted a randomized clinical trial (Stroke Prevention in Sickle Cell Anemia--the "STOP" study) to test a strategy to prevent first stroke in children with sickle cell disease. Over 2000 children were screened with transcranial Doppler ultrasonography and of these, 130 with elevated blood velocity indicating high risk were enrolled in the trial. Regular red cell transfusions sufficient to reduce the percentage of Hb S gene product from over 90 to less than 30 of total hemoglobin was associated with a marked reduction in stroke. The untreated risk of 10% per year was reduced over 90% with treatment, an effect sufficient to cause early termination of the trial. Although treatment was unblinded, the design included blinded adjudication of possible stroke by a panel of neurologists remote from the study sites. The study led to a Clinical Alert, issued by the National Heart, Lung, and Blood Institute, recommending screening and consideration of treatment in children with sickle cell disease and 2 to 16 years of age who are at risk based on transcranial Doppler ultrasonography, and who have not had stroke.

Adolescent↗

PubMed2000

Pigeon lice down under: taxonomy of Australian Campanulotes (Phthiraptera: Philopteridae), with a description of C. durdeni n. sp.

Campanulotes flavus (Rudow, 1869) from Phaps chalcoptera is redescribed and illustrated. C. defectus Tendeiro, 1969, erroneously recorded from the extinct passenger pigeon Ectopistes migratorius, is shown to be a junior synonym of C. flavus, thus removing it from the list of lice thought to have gone extinct with the passenger pigeon. C. flavus elegans (Tendeiro, 1978) from P. elegans is elevated to specific rank and redescribed. Finally, C. durdeni n. sp. is described from its type host Ocyphaps lophotes.

Animals↗

PubMed2000

Validity of a modified version of the Marks Asthma Quality of Life Questionnaire.

To produce a scale useful for individual clinical decision making, the Marks Asthma Quality of Life Questionnaire (AQLQ-M) was modified to a 22-item scale using a 7-point Likert response scale, and the validity of the new instrument was assessed. Adult asthma subjects with moderate to severe disease, recruited from two hospitals in Adelaide, Australia, were surveyed at baseline (n = 293), and at 3-month follow-up (n = 234). Cronbach's alpha for the Total scale of the modified AQLQ-M (MAQLQ-M) was 0.97 and all subscale values exceeded 0.90. Test-retest reliability values for all scales were between 0.88 and 0.93. All correlations between disease reference measures were statistically significant to at least the p < 0.01 level. Stronger associations were seen with symptom and self-rating scales than for lung function, medication usage, and health service utilization measures of outcome. The MAQLQ-M showed good discriminative ability for all asthma symptom categories and for different FEV1 values. Moderate, statistically significant associations were seen between changes in MAQLQ-M scores and clinical measures. Higher baseline MAQLQ-M scores were associated with lower risks over 12 months for hospital admissions (odds ratio, OR = 0.58) and repeated emergency department visits (OR = 0.47). The MAQLQ-M is a highly valid measure of asthma-related quality of life.

Adult↗

PubMed2000

Introduction to cognitive processes of expert pilots.

This report addresses the historical problem that a very high percentage of accidents have been classified as involving "pilot error." Through extensive research since 1977, the Federal Aviation Administration determined that the predominant underlying cause of these types of accidents involved decisional problems or cognitive information processing. To attack these problems, Aeronautical Decision Making (ADM) training materials were developed and tested for ten years. Since the publication of the ADM training manuals in 1987, significant reductions in human performance error (HPE) accidents have been documented both in the U.S. and world wide. However, shortcomings have been observed in the use of these materials for recurrency training and in their relevance to more experienced pilots. The following discussion defines the differences between expert and novice decision makers from a cognitive information processing perspective, correlates the development of expert pilot cognitive processes with training and experience, and reviews accident scenarios which exemplify those processes. This introductory material is a necessary prerequisite to an understanding of how to formulate expert pilot decision making training innovations; and, to continue the record of improved safety through ADM training.

Accidents, Aviation↗

PubMed1999

A South Australian population survey of the ownership of asthma action plans.

OBJECTIVE: To examine the relationships between ownership of written asthma action plans, asthma morbidity, use of devices, and patients' perceptions of their asthma management. DESIGN AND SETTING: A random population survey (in 1996) of the South Australian population aged 15 years or over, using interviewers to administer a questionnaire. PARTICIPANTS: People who reported that they had current, doctor-diagnosed asthma. MAIN OUTCOME MEASURES: Prevalence of written asthma action plans; night-time awakenings from asthma; ownership of peak flow meters; and people's perceptions of their asthma management. RESULTS: The ownership of asthma action plans by people with self-reported asthma was 33% and has declined since 1995 (42%; P < 0.001). Fifteen per cent were awakened weekly or more frequently by asthma symptoms. These people were more likely to have a peak flow meter and a written action plan, but less likely to consider they had been provided with enough information about their asthma, to feel comfortable managing their asthma, or to find it easy to see their doctor. Having a written asthma action plan was associated with regular corticosteroid use, understanding asthma, having enough information and owning a peak flow meter. CONCLUSIONS: Ownership of asthma action plans in South Australia is suboptimal. Before we develop new strategies to improve asthma outcomes, we must determine whether there is a need to target people with less severe asthma and/or improve the use of guidelines by health professionals.

Asthma↗

PubMed1999

Production of atypical measles in rhesus macaques: evidence for disease mediated by immune complex formation and eosinophils in the presence of fusion-inhibiting antibody.

The severe disease atypical measles occurred when individuals immunized with a poorly protective inactivated vaccine contracted measles, and was postulated to be due to a lack of fusion-inhibiting antibodies. Here, rhesus macaques immunized with formalin-inactivated measles vaccine developed transient neutralizing and fusion-inhibiting antibodies, but no cytotoxic T-cell response. Subsequent infection with measles virus caused an atypical rash and pneumonitis, accompanied by immune complex deposition and an increase in eosinophils. Fusion-inhibiting antibody appeared earlier in these monkeys than in non-immunized monkeys. These data indicate that atypical measles results from previous priming for a nonprotective type 2 CD4 T-cell response rather than from lack of functional antibody against the fusion protein.

Animals↗