Infectious mononucleosis and corticosteroids: management practices and outcomes

OBJECTIVE: Although many studies have examined the effects of systemic corticosteroid therapy (SCT) on the clinical course of infectious mononucleosis (IM), few have evaluated the influence of these studies on treatment patterns and outcomes. The purpose of this study was to review current therapeutic strategies and outcomes in uncomplicated and complicated IM. DESIGN: Retrospective case series. SETTING: Tertiary care center. PATIENTS: We identified 206 immunocompetent patients with IM diagnosed during the previous 5 years. Patient information, including age, sex, history and physical findings at presentation, pertinent laboratory data, management practices, and treatment outcomes, were analyzed. INTERVENTIONS: Systemic corticosteroid therapy was used in 44.7% of patients. Evaluation of treatment indications for SCT revealed that 8.0% of the study population qualified by traditional criteria for the use of corticosteroids; 92.0% of patients received SCT for other indications. Factors associated with the observed increase in corticosteroid use included a history of repeat visits, inpatient admission, and otolaryngology consultation. MAIN OUTCOME MEASURES: Diagnosis was made on the basis of a positive heterophil antibody test (monospot test) with appropriate clinical findings (97.5% of patients) or by the presence of lymphocytosis with appropriate clinical findings (2.4% of patients). RESULTS: Systemic corticosteroid therapy was not positively associated with fever, decreased oral intake, tonsillar hypertrophy, or duration of symptoms. No significant differences in incidence of disease complications, rates of hospital admission, or length of hospital stay were noted between the steroid and nonsteroid treatment groups. CONCLUSIONS: Despite consistent and uniform acceptance in the medical literature that SCT in the setting of IM should be reserved for patients with impending airway obstruction, corticosteroids continue to be used on a much broader scale at this tertiary care institution. This observation suggests that clinicians see value in SCT for treatment of IM beyond the classically accepted reasons. Moreover, despite previous reports of possible adverse consequences of SCT in IM, our review failed to demonstrate any such trend.     

Chromosomal polymorphism and comparative painting analysis in the zebra finch

The zebra finch (Taeniopygia guttata) is often studied because of its interesting behaviour and neurobiology. Genetic information on this species has been lacking, making analysis of informative mutants difficult. Here we report on an improved cytological method for preparation of metaphase chromosomes suitable for fluorescent in situ hybridization of adult birds. We found that individual chicken chromosome paints usually hybridized to single zebra finch chromosomes, indicating only minor chromosomal rearrangements since the evolutionary divergence of these two species, and suggesting that the genomic location of chicken genes will predict the location of zebra finch orthologues. Chicken chromosome 1 appears to have split into two macrochromosomes in zebra finches, and chicken chromosome 4 paint hybridizes to a zebra finch macrochromosome and a microchromosome. This pattern was confirmed by mapping the androgen receptor (AR), which is located on chicken chromosome 4 but on a zebra finch microchromosome. We detected a telocentric/submetacentric polymorphism of chromosome 6 in our colony of zebra finches, and found that the polymorphism was inherited in a Mendelian pattern     

Syncope during exercise, documented with continuous blood pressure monitoring during ergometer testing

A 27-year old female had one episode of transient loss of consciousness and several of near-unconsciousness during strenuous exercise and sexual activity. Episodes started with abdominal discomfort or nausea and light headedness. Unconsciousness never exceeded one minute. When trying to stand up, she felt she would lose consciousness again. We performed a bicycle ergometer exercise test, continuously monitoring blood pressure via non-invasive finger photoplethysmography (Finometer, FMS, The Netherlands). Beat-to-beat changes in stroke volume, cardiac output and total peripheral resistance were calculated using Modelflow (FMS, The Netherlands). At a power of 140 W, the patient reported being near exhaustion; shortly after this she reported nausea. She stopped cycling 30 s later, then saw "black spots" and felt an oncoming loss of consciousness. Dismounting the ergometer and squatting provided immediate relief from symptoms. Symptoms during the test were similar to those during previous episodes. The diagnosis was exercise-induced vasovagal reactions. This is the first report that documents the beat-to-beat changes in blood pressure, stroke volume and total peripheral resistance during exercise-induced vasovagal syncope. It illustrates the usefulness of combining exercise testing with continuous non-invasive blood pressure monitoring in the diagnostic work-up of exercise-induced syncope, and shows the therapeutic value of squatting to prevent loss of consciousness in exercise-related vasovagal syncope.     

An item response analysis of the international restless legs syndrome study group rating scale for restless legs syndrome

BACKGROUND AND PURPOSE: Restless legs syndrome (RLS) is a common central nervous system disorder; however, there is currently a lack of well-validated and easily-administered measures of RLS severity available. The International Restless Legs Syndrome Study Group has recently developed a 10-item scale to meet this need. The International Restless Legs Severity Scale (IRLS) has been shown to have a high degree of reliability, validity, and internal consistency. In order to further demonstrate the validity of the IRLS, the present study examined the relationship between scores on individual IRLS items and overall RLS severity. PATIENTS AND METHODS: The 10-item IRLS was administered to 196 RLS patients. Option characteristic curves (the probability of scoring different options for a given item as a function of overall IRLS score) were generated in order to illustrate the scoring patterns for each item across the range of total RLS severity. Item characteristic curves (the expected score on an item as a function of overall IRLS score) were also generated to illustrate the relationship between scores on the individual items and total RLS severity. RESULTS: The IRLS items demonstrated excellent item response properties, with option and item characteristic curves closely approximating those of an ideal item. Item 3 (relief of arm or leg discomfort from moving around) was the most problematic item in that a 'floor' effect was evident; however, the item response characteristics for this item were still acceptable. CONCLUSIONS: Each IRLS item showed a good relationship between responses on that item and overall RLS severity, providing further evidence for the validity of the IRLS as a measure of RLS severity in RLS patients.     

An optimal state estimation model of sensory integration in human postural balance

We propose a model for human postural balance, combining state feedback control with optimal state estimation. State estimation uses an internal model of body and sensor dynamics to process sensor information and determine body orientation. Three sensory modalities are modeled: joint proprioception, vestibular organs in the inner ear, and vision. These are mated with a two degree-of-freedom model of body dynamics in the sagittal plane. Linear quadratic optimal control is used to design state feedback and estimation gains. Nine free parameters define the control objective and the signal-to-noise ratios of the sensors. The model predicts statistical properties of human sway in terms of covariance of ankle and hip motion. These predictions are compared with normal human responses to alterations in sensory conditions. With a single parameter set, the model successfully reproduces the general nature of postural motion as a function of sensory environment. Parameter variations reveal that the model is highly robust under normal sensory conditions, but not when two or more sensors are inaccurate. This behavior is similar to that of normal human subjects. We propose that age-related sensory changes may be modeled with decreased signal-to-noise ratios, and compare the model's behavior with degraded sensors against experimental measurements from older adults. We also examine removal of the model's vestibular sense, which leads to instability similar to that observed in bilateral vestibular loss subjects. The model may be useful for predicting which sensors are most critical for balance, and how much they can deteriorate before posture becomes unstable.     

Gender differences in cerebral blood flow velocity and autoregulation between the anterior and posterior circulations in healthy children

There is little information on gender differences in cerebral autoregulation. The purpose of this study was to compare autoregulation of the anterior and posterior circulations using the tilt test method in healthy boys and girls who were 10-16 y of age. Transcranial Doppler was used to measure middle cerebral artery and basilar artery flow velocities (Vmca and Vbas). Cerebral autoregulation (ARI) of the middle cerebral (ARImca) and basilar arteries (ARIbas) was examined using the tilt test method. An ARI <0.4 indicates impaired autoregulation. Among the 13 boys and 13 girls, Vmca and Vbas were higher in girls. All children demonstrated intact autoregulation, but boys had higher ARImca than girls, whereas girls had higher ARIbas than boys. Girls demonstrated greater autoregulation in the basilar artery, whereas boys demonstrated greater autoregulation in the middle cerebral artery. Girls had higher flow velocities in both vessels. This study provides normative data on cerebral autoregulation of the posterior circulation in healthy, awake boys and girls.     

Novel approaches to the nutritional management of the allergic infant

The increased prevalence of atopic diseases, i.e. atopic eczema, allergic rhinitis and asthma, has been described as the epidemic of the 21st century in Western societies. New approaches in the fight against allergic diseases are clearly called for, the target being the persistence of the allergic responder pattern beyond infancy. The advantage afforded by elimination diets lies in the silencing of specific allergic inflammation induced by an offending food. Novel nutritional approaches, beyond the treatment of food allergies, have recently attracted research interest subsequent to the identification of the immunomodulatory potential of specific dietary compounds. Dietary lipids as immunomodulators may prevent allergic sensitization by down-regulating inflammatory response whilst protecting the epithelial barrier. Probiotic bacteria have been shown to reinforce the different lines of gut defence: immune exclusion, immune elimination and immune regulation. On this basis, the strategy against allergic disease proposed here is based on the administration of tolerogenic gut-processed peptide fragments of a specific protein, in addition to the use of specific dietary compounds such as fatty acids and antioxidants, and introducing a microbial stimulus for the immature immune system by means of cultures of beneficial live micro-organisms characteristic of the healthy infant gut microbiota.     

Factors affecting rheumatoid arthritis patients' decisions to participate in clinical trials

OBJECTIVE: To delineate the personal, psychosocial, and disease-related factors that may influence rheumatoid arthritis (RA) patients' decisions to participate in clinical trials. METHODS: A total of 191 patients with RA were asked to participate in this survey. The questionnaire collected information on demographics, RA disease-related factors, and the importance of several factors that might influence patients' willingness to participate in clinical trials. Patients were then asked if they would consider participating in a hypothetical study. RESULTS: Participants were 88% female with a mean age of 40.5 years. The ethnic composition was 57% Hispanic, 25% Caucasian, 12% Asian, and 6% African American, with 71% having a family income < $20,000/year. Factors that patients considered important for participation in a clinical study included: the opportunity to help others, the possibility of improved health, early access to new therapy, the availability of free treatments, unknown side effects of the study drug, and the need to stop current therapy. There were strong correlations between the rank order importance weights between Hispanics and Caucasians, suggesting fundamental similarities in preferences. The most important factor was the opportunity to help others. In general, the more important factors were associated with preferences for trial participation. CONCLUSION: This questionnaire identified factors that may affect RA patients' willingness to participate in a study. Patient participation in trials is driven by diverse factors that include altruism and the opportunity for healthcare and improved health. Consideration of these factors may facilitate the inclusion of more diverse patient populations into trials and enhance the applicability of trial results.