Changing attentional demands in left hemispatial neglect.

Seven variations of a letter cancellation test were used to examine how varying attentional demands affect hemispatial neglect in patients with right hemisphere lesions. While the 14 targets always remained in the same location, the number of distractors (zero, nine, 28, or 82) as well as their complexity (one letter or nine different letters) were varied. The percentage of targets canceled in the left hemispace was linearly related to the number of distractors. There were no differences between the complexity conditions. In a second study, the same 14 targets were presented but the distractors (zero, 14, or 41) were all placed on the right. Increasing the number of distractors on the right increased neglect on both sides of the space. Taken together, these results suggest that, while the limited attentional resources of the left hemisphere are biased toward the right hemispace, the absence of contralateral attentional demands allows these resources to be directed ipsilaterally.     

BUILDING COMMUNITY: Developing Skills for Interprofessional Health Professions Education and Relationship-Centered Care

In 1995, the National League for Nursing commissioned a Panel on Interdisciplinary/Transdisciplinary Education. The focus of the Panel's work was to examine educational issues that transcend the health professions and to make recommendations for future implementation of an interdisciplinary approach to addressing them. This article is being simultaneously published by several professional journals. The goal is to seek as much feedback as possible.     

Developing a Peer Review Process for Web-based Curricula

The World Wide Web creates new challenges and opportunities for medical educators. Prominent among these are the lack of consistent standards by which to evaluate web-based educational tools. We present the instrument that was used to review web-based innovations in medical education submissions to the 2003 Society of General Internal Medicine (SGIM) national meeting, and discuss the process used by the SGIM web-based clinical curriculum interest group to develop the instrument. The 5 highest-ranked submissions are summarized with commentary from the reviewers.     

Haemophilus ducreyi infection in south Florida: a rare disease on the rise?

Increased numbers of patients with genital ulcers sought medical attention in the Palm Beach County, Florida, Sexually Transmitted Disease clinics from Aug 1, 1982 to Aug 31, 1983. We established that a small proportion of subsequent cases of genital ulcers were caused by Haemophilus ducreyi, the etiologic agent associated with chancroid. We also set up a surveillance system to monitor this sexually transmitted infection, and have illuminated several recent cases of chancroid occurring in that area. This outbreak of chancroid suggest that clinicians practicing in south Florida consider chancroid (generally a rare disease in the United States) in their differential diagnoses of genital ulcers.     

Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

Reduced cerebral blood flow, oxygen delivery, and electroencephalographic activity after traumatic brain injury and mild hemorrhage in cats.

The authors investigated the effects of transient, mild hemorrhagic hypotension after fluid-percussion traumatic brain injury on intracranial pressure, cerebral blood flow (CBF), cerebral oxygen delivery (CBF x arterial O2 content), and electroencephalographic (EEG) activity. Adult mongrel cats were anesthetized with 1.6% isoflurane in N2O:O2 (70:30) and prepared for trauma and for radioactive microsphere CBF measurement. Isoflurane concentration was decreased to 0.8%, and the cats were randomly assigned to one of four control groups or to an experimental group. Animals in the four control groups underwent either mild hemorrhage (18 ml.kg-1) immediately followed by resuscitation with equal volumes of 10% Hetastarch (eight cats), mild hemorrhage followed by replacement of shed blood (six cats), isovolemic hemodilution with 18 ml.kg-1 of Hetastarch (six cats), or moderate (2.2 atm) trauma alone (eight cats). The experimental group received a combination of trauma and mild hemorrhage followed by resuscitation with Hetastarch (eight cats). Mild hemorrhage produced no significant changes in CBF, renal blood flow, or cardiac output. Following resuscitation from mild hemorrhage, mean arterial blood pressure, cardiac output, renal blood flow, and CBF were not significantly different from baseline; cardiac output and renal blood flow did not differ significantly from baseline 2 hours after Hetastarch resuscitation. Neither hemorrhage nor trauma alone produced significant decreases in CBF or in EEG activity, but trauma followed by hemorrhage and resuscitation produced significant (p less than 0.01) decreases in CBF, cerebral oxygen delivery, and EEG score. These data demonstrate that, following traumatic brain injury, even mild hemorrhagic hypotension is associated with significant deficits in cerebral oxygen availability and neurological function.     

Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group

Multiple sclerosis (MS) is a demyelinating autoimmune disease of the central nervous system. While its etiology is not well understood, genetic factors are clearly involved. Until recently, most genetic studies in MS have been association studies using the case-control design testing specific candidate genes and studying only sporadic cases. The only consistently replicated finding has been an association with the HLA-DR2 allele within the major histocompatibility complex (MHC) on chromosome 6. Using the genetic linkage design, however, evidence for and against linkage of the MHC to MS has been found, fostering suggestions that sporadic and familial MS have different etiologies. Most recently, two of four genomic screens demonstrated linkage to the MHC, although specific allelic associations were not tested. Here, a dataset of 98 multiplex families was studied to test for an association to the HLA-DR2 allele in familial MS and to determine if genetic linkage to the MHC was due solely to such an association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta) in the MHC demonstrated strong genetic linkage (parametric lod scores of 4.60, 2.20 and 1.24, respectively) and a specific association with the HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results by HLA-DR2 status showed that the linkage results were limited to families segregating HLA-DR2 alleles. These results demonstrate that genetic linkage to the MHC can be explained by the HLA-DR2 allelic association. They also indicate that sporadic and familial MS share a common genetic susceptibility. In addition, preliminary calculations suggest that the MHC explains between 17 and 62% of the genetic etiology of MS. This heterogeneity is also supported by the minority of families showing no linkage or association with loci within the MHC.