Hormonal regulation of food intake

Our knowledge of the physiological systems controlling energy homeostasis has increased dramatically over the last decade. The roles of peripheral signals from adipose tissue, pancreas, and the gastrointestinal tract reflecting short- and long-term nutritional status are now being described. Such signals influence central circuits in the hypothalamus, brain stem, and limbic system to modulate neuropeptide release and hence food intake and energy expenditure. This review discusses the peripheral hormones and central neuronal pathways that contribute to control of appetite.     

Numerical Simulation of Magnetic Resonance Angiographies of an Anatomically Realistic Stenotic Carotid Bifurcation

Magnetic Resonance Angiography (MRA) has become a routine imaging modality for the clinical evaluation of obstructive vascular disease. However, complex circulatory flow patterns, which redistribute the Magnetic Resonance (MR) signal in a complicated way, may generate flow artifacts and impair image quality. Numerical simulation of MRAs is a useful tool to study the mechanisms of artifactual signal production. The present study proposes a new approach to perform such simulations, applicable to complex anatomically realistic vascular geometries. Both the Navier-Stokes and the Bloch equations are solved on the same mesh to obtain the distribution of modulus and phase of the magnetization. The simulated angiography is subsequently constructed by a simple geometric procedure mapping the physical plane into the MRA image plane. Steady bidimensional numerical simulations of MRAs of an anatomically realistic severely stenotic carotid artery bifurcation are presented, for both time-of-flight and contrast-enhanced imaging modalities. These simulations are validated by qualitative comparison with flow phantom experiments performed under comparable conditions.     

Withdrawal of warfarin prior to a surgical procedure: time to follow the guidelines?

BACKGROUND AND OBJECTIVE: Patients with cardiogenic sources of embolism may be at increased risk of cerebral infarction when anticoagulation therapy is suspended for surgical procedures. The purpose of this study was to determine frequency of cardioembolic cerebral infarction during periprocedural warfarin withdrawal. METHODS: Retrospective analysis of prospective cerebral infarction registry data from two tertiary medical centers. RESULTS: Over a 12-month period, 14 cases of cardioembolic cerebral infarction occurring during the period of warfarin withdrawal for a medical procedure were observed, accounting for 7.1% of the 197 cardioembolic cerebral infarctions encountered. Across all patients, cerebral infarctions developed an average of 5.4 days after the last dose of warfarin (range 3-8). Among the 14 patients (8 males and 6 females) with warfarin cessation-related infarcts, age ranged from 54 to 91 years. Each had been on chronic anticoagulation with warfarin for more than 1 year. Retrospective analysis suggested that all these cerebral infarctions had been potentially preventable. In each case, either the planned procedure did not require discontinuation of warfarin or, when withdrawal was required, no bridging, parenteral anticoagulation was provided to lessen the risk during the warfarin-free period. CONCLUSION: Patients at high risk of cardioembolic cerebral infarction may benefit from more intensive management strategies to reduce cerebral infarction risk during periprocedural periods.     

Stability, reliability, and norms for the inventory of interpersonal problems

Abstract Data were collected on interpersonal functioning that could be used to evaluate therapeutic outcome for individual clients. The Inventory of Interpersonal Problems (IIP) was administered three times over five weeks to undergraduates, none of whom were currently in therapy. Based on selection using an accepted measure of psychological distress (Outcome Questionnaire-45.2; Lambert, 1996), 107 participants were identified as having high psychological distress (high problem) and 172 as having low (low problem) or no (asymptomatic) levels of distress. The high sample was found to be roughly equivalent to a client sample on the IIP. The IIP demonstrated acceptable reliability and stability over five weeks across subsamples, providing potential data for estimating pretherapy baselines. Comparing the low-problem and asymptomatic samples with the high-problem sample provided norms, cut scores, and reliable change indices for interpersonal functioning. Several IIP measures, including distress and each of the quadrant scores, demonstrated adequacy in classification of participants into clinical or nonclinical categories.     

Outcomes in Acute Ischemic Stroke Patients Without Angiographically Documented Arterial Occlusion

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke who undergo emergent cerebral angiography for consideration of intra-arterial treatment and do not have an angiographically demonstrable occlusion pose a management dilemma. The authors reviewed their experience to determine the clinical out comes of patients with ischemic stroke evaluated within 6 hours of symptom onset in whom negative angiograms were obtained. METHODS: A prospective registry was maintained for all patients (N = 56) who were considered for intra-arterial thrombolysis. Patients without angiographic arterial occlusion were not treated with thrombolytics, and data pertaining to clinical characteristics and neuroimaging findings was collected. Follow-up data were acquired through clinic visits or telephone interviews at 5.5 +/- 5.0 months (mean +/- SD), range 1 to 15 months, after onset of stroke. RESULTS: Of the 56 patients, no arterial occlusion was observed in 17 (30%) patients (mean age 65.8 +/- 13.0 years; 7 were men). The mean (+/- SD) baseline National Institute of Health stroke scale score was 10.2 +/- 7.1. Symptoms were referable to the anterior or posterior circulation in 76% and 18% of the patients, respectively; they could not be localized to either circulation in 6%. Follow-up neuroimaging studies demonstrated cerebral infarction in 12 of 14 patients. Eleven of the 17 had a favorable long-term recovery as assessed by the modified Rankin Scale (score 0 or 1). Five other patients had modified Rankin Scale scores of 3 (n = 1), 4 (n = 2), or 5 (n = 2). One patient died during the follow-up period. With regard to location of ischemic deficits, the highest rate of death or dependency was observed in patients with pontine infarction (three of four patients). CONCLUSION: Although the outcome following ischemic stroke in patients without angiographically documented occlusion appears to be better than that reported for patients with angiographically documented occlusion, death or disability is observed in at least one third of the patients. There fore, acute ischemic stroke in the absence of angiographic occlusion is not entirely a "benign" entity and can be particularly devastating when the brainstem is involved.     

Sleep disturbances in patients treated for panic disorder

BACKGROUND AND PURPOSE: Disturbed night sleep is a common complaint of patients with panic disorder. The aim of the present study was to demonstrate whether the sleep disturbances can be successively influenced by the standard therapy for treating panic disorder. PATIENTS AND METHODS: Psychiatric examinations of 20 outpatients with panic disorder were supplemented with a study of sleep quality using standardised interviews, sleep logs and polysomnographic recordings. RESULTS: A statistical comparison of data showed that reduced anxiety after successful treatment of panic disorder was not necessarily followed by improved sleep parameters. CONCLUSION: The results suggest that the conventional therapy applied to these patients is not sufficient to treat the co-existing insomnia. Consequently, it seems to be of importance to supplement the treatment of panic disorders with specific treatment of the sleep disturbance.     

Tools, works of art, psychoanalysis

The roots of psychoanalysis lie deep within the evolutionary history of human life and intelligence. In this article I will explore a set of evolving relationships between human beings and the artifacts they have created. The psychoanalytic treatment method is one such artifact, despite the apparent reluctance of many psychoanalysts to describe what they do in terms that might be interpreted to minimize the personal element in their work with their patients. But the personal element can be effectively understood only through the study of individual human beings interacting with their surroundings. Psychoanalysis is a lineal descendent of simpler and earlier interactions with a special group of artifacts, those that incorporate human meanings in a way that provides a continuous source of feedback information.     

Six revolutions in vaccinology

The history of vaccine development can be divided into 5 waves, produced by revolutions in technology. They are attenuation, inactivation, cell culture of viruses, genetic engineering and methods to induce cellular immune responses. This division is somewhat artificial, and all of the past strategies continue to be useful. I discuss the candidates for the sixth revolution, which include combination vaccines, new adjuvants, proteomics, reverse vaccinology and vaccines for noninfectious diseases, among others. I propose new delivery systems as the most likely to succeed, although humbly admitting that prediction is always subject to error.