Autonomic control of cardiovascular function: clinical evaluation in health and disease

The high- and low-pressure baroreceptor reflexes are integral to the control of blood pressure by the autonomic nervous system. Tests of the integrity of these baroreflexes make it possible to identify the site of autonomic dysfunction in patients with orthostatic hypotension. Clinical characteristics and typical results of autonomic testing in patients with autonomic failure, with carotid sinus hypersensitivity, and with hyperadrenergic autonomic dysfunction are described in this review.     

Prevalence of depressive symptoms and depressive disorder in primary care patients over 65 years of age

Several reports suggest that pretreatment of intracoronary thrombus with fibrinolytic agents may reduce the risk for complications during subsequent balloon angioplasty. We report a case, for the first time, of successful lysis of an extensive thrombus in a native coronary artery by administering a prolonged intracoronary infusion of streptokinase to facilitate subsequent angioplasty and discuss the management strategy when intracoronary thrombus is encountered.     

Studies on the efficacy of hyperbaric rendering procedures in inactivating bovine spongiform encephalopathy (BSE) and scrapie agents

The efficacy of the procedures in use at the two rendering plants in the Netherlands was assessed on a laboratory-scale using procedures that simulated the pressure cooking part of the rendering process. A pool of bovine spongiform encephalopathy (BSE)-infected brainstem from the United Kingdom and a pool of scrapie-infected brainstem from Dutch sheep were used to spike the rendering materials. The mixtures were subjected to various time-temperature combinations of hyperbaric heat treatment related to the conditions used in Dutch rendering plants in the early 1990s, and to the combination of 20 minutes at 133 degrees C required by the EU Directive on rendering of 1996. The efficacy of the procedures in inactivating BSE or scrapie infectivity was measured by titrating the materials before and after heat treatment in inbred mice, by combined intracerebral and intraperitoneal inoculations at limiting dilutions. Two independent series of experiments were carried out. The design of the study allowed for minimum inactivations of up to 2.2 log (2.0 in the second series) to be measured in the diluted infective material and 3.1 log in the undiluted material. After 20 minutes at 133 degrees C there was a reduction of BSE infectivity of about 2.2 log in the first series (with some residual infectivity detected), and in the second series more than 2.0 log (with no residual infectivity detected). With undiluted brain material there was an inactivation of about 3.0 log (with some residual infectivity detected). With the same procedure, scrapie infectivity was reduced by more than 1.7 log in the first series and by more than 2.2 log in the second series. With undiluted brain material there was an inactivation of more than 3.1 log. In each case no residual scrapie infectivity was detected. The BSE agent consistently appeared to be more resistant to heat inactivation procedures than the scrapie agent, particularly at lower temperatures and shorter times.     

Systemic lupus erythematosus in three ethnic groups: II. Features predictive of disease activity early in its course. LUMINA Study Group. Lupus in minority populations, nature versus nurture

OBJECTIVE: To determine the factors associated with disease activity in patients with recent-onset (< or =5 years) systemic lupus erythematosus (SLE) who were of Hispanic, African-American, or Caucasian ethnicity. METHODS: Incident and prevalent cases of SLE, as defined by the American College of Rheumatology criteria for SLE, among the 3 ethnic groups were identified in Alabama (The University of Alabama at Birmingham) and Texas (The University of Texas-Houston Health Science Center and The University of Texas Medical Branch at Galveston). Variables from the sociodemographic, clinical, immunologic, immunogenetic, behavioral, and psychological domains were obtained using validated instruments. Disease activity was ascertained with the Systemic Lupus Activity Measure (SLAM). Stepwise domain regressions with SLAM score as the dependent variable were performed. Final ethnic-specific and overall regression models were obtained by entering variables that were retained in the domain regressions. RESULTS: SLAM scores at study entry were higher in the African Americans (mean +/- SD 12.6 +/- 6.9) and Hispanics (11.0 +/- 6.2) than in the Caucasians (8.5 +/- 3.7) (P < or = 0.001). The final overall regression model (R2 = 28%) for higher SLAM score included the following variables: African-American ethnicity, lack of private health insurance, abrupt disease onset, presence of anti-Ro antibodies, absence of HLA-DRB1*0301, higher levels of helplessness, and abnormal illness-related behaviors. CONCLUSION: Socioeconomic, immunologic, immunogenetic, behavioral, and psychological variables were all predictive of disease activity early in the course of SLE, irrespective of ethnic group. However, there remain ethnic group differences in disease activity that were not explained by these factors.     

Langerhans' cell histiocytosis and juvenile xanthogranuloma of the orbit. Clinicopathologic, CT, and MR imaging features

The clinical, radiologic, and histopathologic features of two main disorders of the orbit are discussed. Group I, Langerhans cell histiocytosis (histiocytosis X, Class I), is caused by proliferation of X histiocytic Langerhans' cells. Group II is juvenile xanthogranuloma, and Class II is related to the proliferation of non-X histiocytic (monocyte-macrophage) cells. The two diseases are of unknown cause and differ in their clinical, radiologic, and histopathologic features.