Langerhans cell histiocytosis patients have HLA Cw7 and DR4 types associated with specific clinical presentations and no increased frequency in polymorphisms of the tumor necrosis factor alpha promoter

BACKGROUND: Current theory on the etiology of Langerhans cell histiocytosis (LCH), formerly Histiocytosis-X, is that abnormality(ies) of the immune system are responsible for dysregulation of Langerhans cells (LC) in patients' lesions. Among the known abnormalities in LCH patients are increased amounts of tumor necrosis factor alpha (TNF-alpha) and other cytokines in the lesions. PROCEDURE: We investigated the human leukocyte antigen (HLA) phenotypes of 29 patients and 37 healthy family members to determine if any haplotypes segregate with the presence or locations of the disease. The lymphocyte subsets for 22 patients and 11 family members were also determined. RESULTS: Patients with single bone, multiple bone, or multi-system LCH had different relative proportions of HLA types. Patients presenting with single bone disease had an especially high frequency of the DR4 type. In this patient group, every Caucasian patient had either Cw7 or DR4. Lymphopenia was documented in patients who had been off therapy as well as those who only had surgical curetage of their lesions. Family members also had low numbers of T lymphocytes. There were fewer mutations of the TNF-alpha promoter in patients than in the general population. CONCLUSIONS: Although there is an increased percentage of LCH patients with DR4 and/or Cw7 there was also an increased prevalence of this antigen as well as lymphopenia among unaffected family members. Additional genetic and/or environmental factors are necessary to explain this association. TNF-alpha promoter mutations are not responsible for the increased production of this cytokine.     

A component of maize pollen that stimulates larval mosquitoes (Diptera: Culicidae) to feed and increases toxicity of microbial larvicides

To explain how larval Anopheles arabiensis Patton feed effectively in the turbid water in which they frequently develop, we determined whether an extractable component of maize, Zea mays L., pollen enhances feeding by these mosquitoes. Maturing maize produces a copious amount of wind-borne pollen that is nutritious enough and produced over a sufficient period to support the development of at least one generation of anopheline mosquitoes. Larval An. arabiensis readily ingest the contents of maize pollen or the intact pollen grains themselves. An aqueous extract of maize pollen markedly accelerates the rate at which larval An. arabiensis ingest inert particles and strongly enhances the effectiveness of Bti against larval An. arabiensis. We conclude that the ability of larval anopheline mosquitoes to feed on maize pollen in turbid water is enhanced by the release from these pollen grains of a water-soluble phagostimulatory component (or components), which may be used to increase ingestion of microbial entomotoxins.     

Personality and symptom sensitivity predictors of alprazolam withdrawal in panic disorder

BACKGROUND: Discontinuation of benzodiazepine (BZ) treatment results in a well-characterized withdrawal syndrome in 40-50% of anxious patients. While numerous studies have established the role of BZ dose, treatment duration, half-life, potency, rate of withdrawal and severity of underling anxiety disorder in predicting severity of withdrawal symptoms, fewer studies have examined the role of psychological and personality factors. METHOD: In 123 panic disorder patients undergoing gradual tapered discontinuation of alprazolam in conjunction with pre-treatment with carbamazepine or placebo, the relationship between measures of 'symptom sensitivity' and 'harm avoidance', and severity of withdrawal symptoms measured as peak severity of symptoms, time before taper needed to be slowed due to symptoms, and ability to complete taper, was examined. RESULTS: After controlling for the less substantial effects of dose, treatment duration, pre-taper anxiety and panic attack frequency, measures of symptom sensitivity and harm avoidance accounted for an additional 3-6% of withdrawal variance. CONCLUSIONS: These results show an effect of symptom sensitivity and harm avoidance on BZ withdrawal symptoms, comparable to prior findings linking dependent personality characteristics to withdrawal severity. Failure to show the expected effect on ability to complete taper may be due to either the more symptomatic nature of the patients in this study.     

Predicting panic disorder among patients with chest pain: an analysis of the literature

As many as 25% of patients with chest pain who come to hospital emergency departments have panic disorder. Rates of panic disorder are even higher among those who present for outpatient evaluation of their chest pain. Unfortunately, panic disorder remains largely undiagnosed and untreated in these settings. The authors reviewed studies published between 1970 and 2001 that addressed the prevalence of panic disorder among persons who seek treatment for chest pain in an emergency department or outpatient cardiology clinic. A meta-analysis of the findings revealed five variables that appear to correlate with higher rates of panic disorder among persons who present with chest pain: 1). absence of coronary artery disease, 2). atypical quality of chest pain, 3). female sex, 4). younger age, and 5). a high level of self-reported anxiety. Further studies of these and other variables associated with panic disorder should aid in the detection of this disabling but treatable cause of chest pain.     

Prevalence and correlates of panic attacks in postmenopausal women: results from an ancillary study to the Women's Health Initiative

BACKGROUND: Panic attacks are known to be more common in women than in men, but the prevalence and correlates of panic in the postmenopausal period have not been well defined. METHODS: Cross-sectional survey of 3369 community-dwelling postmenopausal women enrolled between December 1, 1997, and November 30, 2000, in the Myocardial Ischemia and Migraine Study, a 10-center ancillary study of the 40-center Women's Health Initiative. Participants, aged 50 to 79 years and predominantly white (73%), completed questionnaires about the occurrence of panic attacks in the previous 6 months and about migraine headaches and underwent 24-hour ambulatory electrocardiographic monitoring. The 6-month prevalences of full-blown and limited-symptom panic attacks were calculated, and their associations with other sociodemographic and clinical variables were examined in multivariate analyses. RESULTS: One of the panic attack types was reported by 17.9% (95% confidence interval, 16.6%-19.2%) of women (full-blown attacks, 9.8%; limited-symptom attacks, 8.1%). Adjusting for age and race or ethnicity, full-blown panic attacks were more common in women with a history of migraine, emphysema, cardiovascular disease, chest pain during ambulatory electrocardiography, and symptoms of depression. Full-blown panic attacks were associated in a dose-response manner with negative life events during the past year. Panic attacks were associated with functional impairment even after adjusting for comorbid medical conditions and depression. There was no significant association with self-reported use of hormone replacement therapy. CONCLUSIONS: Panic attacks may be relatively common among postmenopausal women and seem to be associated with stressful life events, medical comorbidity, and functional impairment.     

Electrocardiographic manifestations: ventricular tachycardia

Ventricular tachycardia is a serious rhythm disturbance that originates from any part of the myocardium or conduction system below the atrioventricular node. Ventricular tachycardia (VT) presents with a wide QRS complex and a rate greater than 120 beats/min. Ventricular tachycardia is frequently encountered as a complication of coronary artery disease or cardiomyopathy; furthermore, VT is also seen in patients with medication adverse effect or electrolyte disturbance. Ventricular tachycardia presents electrocardiographically in several forms, including monomorphic and polymorphic VT. As is true in most Emergency Department presentations, the Emergency Physician must approach the dysrhythmic patient from an undifferentiated perspective, in this instance, the wide complex tachycardia (WCT) scenario. The electrocardiographic differential diagnosis of WCT classically includes VT and supraventricular tachycardia with aberrant intra-ventricular conduction. This article will review the electrocardiographic presentations encountered in patients with ventricular tachycardia.     

Status report: Development of emergency medicine research since the Macy Report

In Williamsburg, VA, April 17 to 20, 1994, the Josiah Macy, Jr. Foundation sponsored a conference entitled "The Role of Emergency Medicine in the Future of American Medical Care," a report on which was published in Annals in 1995. This report promulgated recommendations for the development and enhancement of academic departments of emergency medicine and a conference to develop an agenda for research in emergency medicine. The American College of Emergency Physicians' Research Committee, along with several ad hoc members, presents updates in several of the areas addressed by the Macy Report and subsequent conferences, as a status report for the development of emergency medicine research as a whole, as of late 2002.     

Electrocardiographic manifestations: wide complex tachycardia due to accessory pathway

Tachycardia with a wide QRS complex is usually due to ventricular tachycardia (VT), supraventricular tachycardia (SVT) with aberrant intraventricular conduction, or an accessory pathway-mediated dysrhythmia. The most common type of accessory pathway causing a wide complex tachycardia is the atrioventricular bypass tract. Distinguishing the accessory pathway-mediated tachycardia from VT or SVT with aberrancy is often difficult, but has important clinical consequences. This article will review the diagnosis of wide complex tachycardia due to an accessory pathway and its related management in the emergent setting.