The universal 2012 definition of myocardial infarction compared to the 2007 definition

Objectives: The third Universal 2012 definition of myocardial infarction (MI) has not been compared to the Universal 2007 definition with regard to the number of cases identified, classification and mortality.

Design: We examined potential MI events according to the two universal definitions in 1494 patients admitted to the University hospital during the 12 months. Patients were included either because of an MI discharge diagnosis (815 patients) or due to elevated troponin I levels without an MI discharge diagnosis (679 patients).

Results: Applying the Universal 2012 definition resulted in 760 of the 1494 patients suffering from MI, as compared to 769 according to the Universal 2007 definition. The lower number of MI events applying the 2012 definition was mainly explained by the stricter definition of Type 4a MI. The 760?MI events were classified as Type 1 (685), 2 (27), 3 (28), 4a (13), 4b (3) and 5 (4).

Conclusions: The application of the third Universal 2012 definition of MI instead of the Universal 2007 definition resulted in a 1% reduction of the total number of MIs. For a practical clinical purpose, the reduction was confined to patients with Type 4a MI. The change of definition had no impact on all-cause mortality.     

Early bacteremia in pediatric hematopoietic stem cell transplant patients on oral antibiotic prophylaxis

BACKGROUND: Bacteremia occurs during hematopoietic stem cell transplant (HSCT) in 20%-25% of patients and the use of gut decontamination (GD) to decrease this risk is controversial. Our purpose was to determine the incidence of bacteremia and antimicrobial resistance post-HSCT in pediatric patients receiving GD, and to identify risk factors associated with infection. PROCEDURES: This was a retrospective cohort study of 182 pediatric patients undergoing first HSCT for malignant disease at The Children's Hospital of Philadelphia from January, 1999 to December, 2002. We examined the impact of age, sex, race, diagnosis, disease status, conditioning regimen, recent bacteremia, stem cell source, donor, graft versus host disease prophylaxis agents, and mucositis severity using Cox proportional hazard models. GD consisted of amoxicillin (azithromycin, if penicillin allergic) and oral gentamicin. Outcome was first episode of bacteremia prior to absolute neutrophil count (ANC) 500/mm(3). Antibiotic susceptibilities were performed on all isolates. RESULTS: Seventy-four patients (41%) developed bacteremia. The majority were Gram-positive cocci, with Staphylococcal (50%) and Streptococcal species (28%) the most common. Gram-negative organisms were identified in 22% with Pseudomonas (5.7%) and Klebsiella species (3.4%) the most common. Of the Streptococcal infections, 72% were resistant to ampicillin; only 25% of the Gram-negative bacteria were resistant to gentamicin. Race was the only factor associated with early bacteremia (hazard ratio 2.3 for non-Caucasian, non-African-American patients, CI 1.3-4.3, P = 0.007). CONCLUSIONS: Early bacteremia is common after HSCT, despite the use of GD. Resistant Gram-positive organisms predominate, consistent with recent trends in immunocompromised patients. Although used in practice, there is no clear evidence for the efficacy of GD and this study provides the basis upon which to develop a randomized clinical trial evaluating the current GD regimen with placebo.     

Patients' request for and emergency physicians' prescription of antimicrobial prophylaxis for anthrax during the 2001 bioterrorism-related outbreak

Background  

Inappropriate use of antibiotics by individuals worried about biological agent exposures during bioterrorism events is an important public health concern. However, little is documented about the extent to which individuals with self-identified risk of anthrax exposure approached physicians for antimicrobial prophylaxis during the 2001 bioterrorism attacks in the United States.     

Buchbesprechungen

Ohne Zusammenfassung     

Investigating the association between antibiotic use and antibiotic resistance: impact of different methods of categorising prior antibiotic use

Many studies have explored the association between antibiotic use and antibiotic resistance. However, methods employed in these studies to categorise prior antibiotic use (e.g. by class, by spectrum) have not been well described. The impact of using different categorisation methods on identifying risk factors for resistance is unknown. To explore these issues, we focused on extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp. (ESBL-EK) as a model. First, we conducted a systematic review of studies of risk factors for ESBL-EK to characterise past approaches to categorising antibiotic use. Second, we re-analysed data from a prior study of risk factors for ESBL-EK. Two separate multivariate models of risk factors for ESBL-EK were constructed: one with prior antibiotic use categorised by class and the other with prior antibiotic use categorised by spectrum of activity. Among the 20 articles that met the inclusion criteria for the systematic review, there was tremendous variability in how prior antibiotic use was categorised (e.g. by agent, class, spectrum and/or a combination of these). No study justified its choice of categorisation method. In the re-analysis of the existing data set, multivariate models of risk factors for ESBL-EK using 'class' and 'spectrum' categorisations differed substantially. In conclusion, there has been no consistent approach to categorising antibiotic use in studies of risk factors for ESBL-EK. Different categorisation schemes were shown to have a substantial impact on study results, particularly for the antibiotic exposures associated with resistance. Elucidating these issues is critical if effective strategies to curb resistance are to be designed.     

Obesity and NK cells affect the expression of the long form of the leptin receptor Ob-Rb in liver of F344 rats

In obesity, the regulatory effects of leptin, a primarily adipocyte-derived hormone, are severely disturbed affecting the control of energy homeostasis and immune functions. In addition, recent studies indicate that specific immune cells can affect glucose and lipid metabolism of liver. However, the contribution of body weight and immune cells, such as Natural Killer (NK) cells, to the regulation of the leptin-receptor expression remains elusive. Therefore, we investigated the expression of the signal-transducing long form of the leptin receptor (Ob-Rb) in diet-induced obesity and after adoptive cross-over NK cell transfer between normal weight and obese male F344 rats. Expression of Ob-Rb was significantly increased in liver in diet-induced obese rats as compared to normal weight littermates. Similarly, the expression of Ob-Rb was higher in liver of obese animals that received NK cells from either obese or normal weight donors as compared to normal weight animals that received NK cells from normal weight donors. Interestingly, normal weight animals that were transferred with NK cells from obese donors also showed a tendency towards a higher Ob-Rb expression. In contrast to the findings in liver, the expression of Ob-Rb in spleen or lung remained unaffected by changes in body weight or cross-over NK cell transfer. Our results suggest that the expression of Ob-Rb mRNA in liver, but not in spleen or lung, is dependent on the body weight but can also be influenced by NK cells, thereby indicating a bidirectional cross-talk between the metabolic and the immune system.     

Obesity and the Associated Mediators Leptin,Estrogen and IGF-I Enhance the Cell Proliferation and Early Tumorigenesis of Breast Cancer Cells

Breast cancer continues to be a major cause of cancer deaths in women. Estrogen, which is also produced by the adipose tissue, is held responsible for the elevated risk of breast cancer in obese women. However, the adipose tissue secrets hormones and adipokines such as leptin and IGF-I and these substances could also contribute to an increased breast cancer risk for obese women. In this study, the impact of obesity on cell proliferation was investigated. The carcinogen 7, 12, dimethylbenz[a]anthracene (DMBA) was administered to normal weight and diet-induced obese female Sprague-Dawley rats. Cell proliferation was evaluated by immunohistological staining of BrdU-incorporation. In the mammary glands and inguinal lymphatic nodes of the obese rats, cell proliferation was significantly increased, indicating a significant influence of obesity on breast cancer. Effects of leptin, estrogen, and IGF-I on the proliferation of MCF-7 cells in vitro were assessed using an MTT assay. Cell culture experiments demonstrated a mitogenic role of these three mediators on cell proliferation. Our data demonstrate a stimulative effect of substances produced by the adipose tissue on breast cancer. Body weight specific cell proliferation suggests that obesity-related adipokines and mediators enhance cell proliferation and increase the risk for breast cancer.