Trauma systems and emergency medicine

The impact of trauma is a major public health challenge which is likely to escalate in the early 21st century. A systematic approach to this problem is required. This review explains the conceptual framework that defines a trauma system, gives a brief historical perspective and describes some of the essential elements of the system which should make a difference to patient outcome. Emergency physicians are well placed to play a leading role in the development and implementation of trauma systems.     

Introduction to molecular cystic fibrosis testing.

Technology improvements are rapidly bringing molecular diagnostics into routine laboratories. Recent recommendations for cystic fibrosis carrier testing by the American College of Medical Genetics (ACMG) have led to commercial test kit development and increased testing volumes. Molecular testing of genetic diseases presents a variety of challenges and situations that may be unfamiliar to laboratories with limited molecular genetic experience. We will briefly review the disease and discuss mutation testing indications, methodologies, quality assurance, and reporting issues associated with cystic fibrosis testing.     

Heart rate changes in chronic insomnia

This study assessed physiological activity in patients with chronic insomnia before sleep, during sleep and in response to acute stress. Twenty-four subjects with chronic insomnia and 25 normal sleepers slept in the laboratory overnight and were given a stressful performance task in the morning. Heart rate was significantly higher in the insomniac group at night. The next morning, heart rate was not different at baseline, but was significantly higher during the performance task in the insomniac group. These results are discussed as supporting the notion that insomniacs have greater physiological responsivity to stress. Further research is needed to determine if altered physiological activity is a cause or consequence of insomnia.     

Inorganic Lead Poisoning in an Adult

Lead poisoning is uncommon in the adult population, but must be considered in the differential diagnosis of patients with abdominal pain of obscure etiology. In this paper we present a 38-yr-old male with abdominal pain, a history of alcohol abuse, and exposure to the virus responsible for acquired immunodeficiency syndrome. The cause of pain was elusive until his occupation as a housepainter was appreciated. The diagnosis of lead poisoning then was considered and confirmed by an elevated blood lead level and symptomatic response to therapy. With the increase in renovation of old buildings, it is likely that the incidence of lead poisoning will become more common.     

Tests for latent tuberculosis

Sir, In their article, Shankar and colleagues underline the significantburden of tuberculosis within their population and the importanceof identifying latent infection     

TRACP Influences Th1 pathways by affecting dendritic cell function.

TRACP, a marker of osteoclasts, is also expressed by cells of the immune system. We identified a novel function for TRACP in the dendritic cell. DCs from TRACP knockout mice have impaired maturation and trigger reduced Th1 responses in vivo. We postulate that TRACP has an important role in the presentation of antigens to T cells. INTRODUCTION: TRACP is highly expressed by osteoclasts, activated macrophages, and dendritic cells (DCs). Knockout mice lacking TRACP have an intrinsic defect in osteoclastic resorption and macrophages that display abnormal immunomodulatory responses and cytokine secretion profiles. Our aim in this study was to investigate the significance of TRACP in the inductive phase of the immune response by examining dendritic cells from TRACP(-/-) mice. MATERIALS AND METHODS: Maturational state and function of leukocyte subsets in mice was assessed by flow cytometry. The ability of the immune system to respond to nonspecific activation and to specific antigen was assessed by delayed type hypersensitivity and the presence of isotype-specific serum antibody in vivo and T-cell proliferation and cytokine production in vitro. RESULTS: The ability of lipopolysaccharide (LPS) to upregulate MHC II and CD80 in DCs from TRACP(-/-) mice was reduced compared with wildtype mice, although production of IL-10 by DCs from TRACP-deficient animals was increased. T- and B-cell responses not involving antigen presentation (anti-CD3, TNP-ficoll) were normal in TRACP(-/-) mice, but responses to T-dependent antigens were impaired. Specifically, TRACP(-/-) mice had defective delayed hypersensitivity responses to picryl chloride and reduced proliferative responses to ovalbumin compared with wildtype mice. In response to ovalbumin, but not anti-CD3, T cells from TRACP(-/-) mice produced less interferon-gamma (IFN-gamma), but there was no difference in IL-4 production: TRACP(-/-) mice also produced less ovalbumin (OVA)-specific IgG2a after immunization. CONCLUSIONS: The finding that DCs from TRACP(-/-) mice have impaired maturation and defective Th1 responses shows that TRACP is important for polarizing responses in na?ve T cells to antigen-presented dendritic cells.     

Influence of hospital characteristics on operative death and survival of patients after major cancer surgery in Ontario.

BACKGROUND: There is a lack of information from Canadian hospitals on the role of hospital characteristics such as procedure volume and teaching status on the survival of patients who undergo major cancer resection. Therefore, we chose to study these relationships using data from patients treated in Ontario hospitals. METHODS: We used the Ontario Cancer Registry from calendar years 1990-2000 to obtain data on patients who underwent surgery for breast, colon, lung or esophageal cancer or who underwent major liver surgery related to a cancer diagnosis between 1990 and 1995 in order to assess the influence of volume of procedures and teaching status of hospitals on in-hospital death rate and long-term survival. For each disease site and before observing patient outcomes data, volume cut-off points were selected to create volume groups with similar numbers of patients. Teaching hospitals were those directly affiliated with a medical school. Logistic regression and proportional hazards models were used to consider the clustering of data at the hospital level and to assess operative death and long-term survival. We also used 4 measures to gauge the degree of procedure regionalization across the province including (1) the number of hospitals performing a procedure; (2) the percentage of patients treated in teaching hospitals; (3) the percentage of rural patients treated in higher volume procedure hospitals; and (4) median distances travelled by patients to receive care. RESULTS: The number of patients in our cohorts who underwent resection of the breast, colon, lung, esophagus or liver was 14 346, 8398, 2698, 629 and 362, respectively. Surgery in a high-volume versus a low-volume hospital did not have a statistically significant influence on the odds of operative death for patients who underwent colon, liver, lung or esophageal cancer resection. The risk of long-term death was increased in low-volume versus high-volume hospitals for patients who underwent resection of the breast (hazard ratio [HR] 1.2, 95% confidence interval [95% CI] 1.0-1.4, p < 0.05), lung (HR 1.3, 95% CI 1.1-1.6, p < 0.01) and liver (HR 1.7, 95% CI 1.0-2.7, p = 0.04). There were no significant differences in the odds of operative (in-hospital) death or risk of long-term death among patients treated in teaching compared with nonteaching hospitals. There was more regionalization of liver, lung and esophageal operations versus breast and colon operations. CONCLUSIONS: Increased hospital procedure volume correlated with improved longterm survival for patients in Ontario who underwent some, but not all, cancer resections, whereas hospital teaching status had no significant impact on patient outcomes. Across the province, further regionalization of care may help improve the quality of some cancer procedures.     

Mapping corpus callosum deficits in autism: an index of aberrant cortical connectivity.

BACKGROUND: Volumetric studies have reported reductions in the size of the corpus callosum (CC) in autism, but the callosal regions contributing to this deficit have differed among studies. In this study, a computational method was used to detect and map the spatial pattern of CC abnormalities in male patients with autism. METHODS: Twenty-four boys with autism (aged 10.0 +/- 3.3 years) and 26 control boys (aged 11.0 +/- 2.5 years) underwent a magnetic resonance imaging (MRI) scan at 3 Tesla. Total and regional areas of the CC were determined using traditional morphometric methods. Three-dimensional (3D) surface models of the CC were also created from the MRI scans. Statistical maps were created to visualize morphologic variability of the CC and to localize regions of callosal thinning in autism. RESULTS: Traditional morphometric methods detected a significant reduction in the total callosal area and in the anterior third of the CC in patients with autism; however, 3D maps revealed significant reductions in both the splenium and genu of the CC in patients. CONCLUSIONS: Statistical maps of the CC revealed callosal deficits in autism with greater precision than traditional morphometric methods. These abnormalities suggest aberrant connections between cortical regions, which is consistent with the hypothesis of abnormal cortical connectivity in autism.