Influence of viewing professional ice hockey on youth hockey injuries.

INTRODUCTION: Most televised National Hockey League (NHL) games include violent body checks, illegal hits and fights. We postulated that minor league players imitated these behaviours and that not seeing these games would reduce the rate of injuries among younger hockey players. METHODS: Using a quasi-experimental design, we compared 7 years of televised NHL matches (2002-2009) with the year of the NHL lock-out (2004/2005). Data from the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were used to identify the injuries and to ascertain whether they were due to intentional contact and illegal acts including fights. RESULTS: We found no significant differences in the proportions of all injuries and those involving intentional contact, violations or illegal acts among male minor league hockey players during the year when professional players were locked out and the years before and after the lock-out. CONCLUSION: We concluded that not seeing televised NHL violence may not reduce injuries, although a possible effect may have been obscured because there was a striking increase in attendance at equally violent minor league games during the lock-out.

The heterodimerization domains of MLL-FYRN and FYRC--are potential target structures in t(4;11) leukemia.

The chromosomal translocation t(4;11)(q21;q23) is a frequent genetic aberration of the mixed lineage leukemia (MLL) gene, predominantly associated with high-risk acute lymphoblastic leukemia (ALL) in pediatric patients. Previous studies demonstrated that mice transplanted with hematopoietic cells expressing the AF4-MLL fusion protein develop proB ALL. The AF4-MLL oncoprotein becomes activated by Taspase1-mediated hydrolysis, which subsequently leads to a heterodimer of the cleavage products AF4-MLL·N and MLL·C. This protein-protein interaction is due to the FYRN and FYRC interaction domains present in both protein fragments. Heterodimerization subsequently induces high-molecular-weight protein complex formation that is protected against SIAH1/2-mediated polyubiquitinylation. Here, we attempted to selectively block this initial heterodimerization step, aiming to prevent the oncogenic activation of the AF4-MLL multiprotein complex. The minimal interaction interface was experimentally defined first in a bacterial two-hybrid system, and then in mammalian cells by using a biosensor assay. Expression of the FYRC domain, or smaller portions thereof, resulted in the inhibition of heterodimer formation, and blocked AF4-MLL multiprotein complex formation with subsequent destruction of the AF4-MLL oncoprotein. Thus, it is in principle possible to specifically target the AF4-MLL protein. This knowledge can now be exploited to design inhibitory decoys in order to destroy the AF4-MLL oncoprotein.

bdhA-patD operon as a virulence determinant, revealed by a novel large-scale approach for identification of Legionella pneumophila mutants defective for amoeba infection.

Legionella pneumophila, the causative agent of Legionnaires' disease, is an intracellular parasite of eukaryotic cells. In the environment, it colonizes amoebae. After being inhaled into the human lung, the bacteria infect and damage alveolar cells in a way that is mechanistically similar to the amoeba infection. Several L. pneumophila traits, among those the Dot/Icm type IVB protein secretion machinery, are essential for exploiting host cells. In our search for novel Legionella virulence factors, we developed an agar plate assay, designated the scatter screen, which allowed screening for mutants deficient in infecting Acanthamoeba castellanii amoebae. Likewise, an L. pneumophila clone bank consisting of 23,000 transposon mutants was investigated here, and 19 different established Legionella virulence genes, for example, dot/icm genes, were identified. Importantly, 70 novel virulence-associated genes were found. One of those is L. pneumophila bdhA, coding for a protein with homology to established 3-hydroxybutyrate dehydrogenases involved in poly-3-hydroxybutyrate metabolism. Our study revealed that bdhA is cotranscribed with patD, encoding a patatin-like protein of L. pneumophila showing phospholipase A and lysophospholipase A activities. In addition to strongly reduced lipolytic activities and increased poly-3-hydroxybutyrate levels, the L. pneumophila bdhA-patD mutant showed a severe replication defect in amoebae and U937 macrophages. Our data suggest that the operon is involved in poly-3-hydroxybutyrate utilization and phospholipolysis and show that the bdhA-patD operon is a virulence determinant of L. pneumophila. In summary, the screen for amoeba-sensitive Legionella clones efficiently isolated mutants that do not grow in amoebae and, in the case of the bdhA-patD mutant, also human cells.

Risk compensation in children's activities: A pilot study.

BACKGROUND: The intent of protective equipment (PE) in sports and leisure activities is to reduce injuries. However, some postulate that any safety measure prompts riskier behaviour, a phenomenon known as 'risk homeostasis' or 'risk compensation.' This study explores one approach to examining this in children. The rationale for this pilot study was to establish if children between six and 16 years old could answer questions about risk-taking sensibly and which questions, if any, could be eliminated; to establish the reliability of response; and to determine the numbers needed for a definitive study. METHODS: Sixty-three children with nonsevere injuries, ages six to 16 years, were interviewed while waiting to be seen at the Montreal Children's Hospital emergency department. An interviewer administered a questionnaire comprising three sections. The first part only applied to those who were injured in an activity for which some form of PE was available (n=19). The second part examined customary risk-taking behaviour using the thrill and adventure seeking scales of a standardized questionnaire (Zuckerman) (n=63). The third section posed hypothetical questions about likely risk-taking when using PE to those who had engaged in such activities (n=58). RESULTS: The approach and questionnaire proved feasible with this age group. The responses suggest that children wearing PE were more likely to report increased risk-taking than those who did not wear PE. For most of the hypothetical questions, the majority also reported changes toward riskier behaviour when using PE. However, those wearing PE scored lower on the thrill and adventure seeking scale, suggesting that they are, by nature, less venturesome. CONCLUSION: The results indicate that risk compensation may modify the effectiveness of PE for children engaged in sports and leisure activities. Conversely, the findings also suggest that those wearing PE may be a cautious subgroup.

In vitro activities of fourteen antimicrobial agents against obligately anaerobic bacteria.

The in vitro activities of fourteen antimicrobial agents were tested against 292 clinical isolates of obligately anaerobic bacteria using the broth microdilution technique. Taking all strains as a group the MIC(50/90) (mg/l) values were metronidazole and imipenem 0.25/1, meropenem 0.25/0.5, trovafloxacin 0.25/1, gatifloxacin and moxifloxacin 0.5/2, levofloxacin 2/16, ciprofloxacin 4/32, clindamycin 0.5/8, amoxycillin/clavulanate 1/4, doxycycline and chloramphenicol 2/4, erythromycin 4/>32 and penicillin G 16/>32.

In vitro activity of telithromycin (HMR 3647) and seven other antimicrobial agents against anaerobic bacteria.

We assessed the in vitro activity of telithromycin (HMR 3647) and seven other antimicrobials against 292 strains of obligately anaerobic bacteria. MICs were determined with the microdilution technique and Wilkins-Chalgren broth according to DIN 58940-83. MIC50/MIC90s (mg/L) for telithromycin were 4/4 for Bacteroides fragilis, Bacteroides ovatus and Bacteroides thetaiotaomicron, 2/4 for Fusobacterium spp. and Bilophila wadsworthia, 2/2 for Bacteroides caccae, 1/4 for Bacteroides vulgatus, 0.25/4 for Prevotella spp., > or =0.03/0.5 for Clostridium spp. and 0.125/4 for Peptostreptococcus spp.

Comparative activity of moxifloxacin in vitro against obligately anaerobic bacteria.

The antimicrobial activity of moxifloxacin and seven other antibiotics (four of them quinolones) against 292 strains of obligately anaerobic bacteria was assessed employing a broth microdilution technique performed in Wilkens-Chalgren broth. MIC50/MIC90 values (mg/l) for moxifloxacin were as follows: Bacteroides fragilis (n = 62) 0.25/2, Bacteroides ovatus (n = 70) 1/4, Bacteroides vulgatus (n = 29) 0.25/1, Bacteroides thetaiotaomicron (n = 17) 2/2, Bacteroides caccae (n = 11) 1/2, Prevotella spp. (n = 11) 0.25/2, Fusobacterium spp. (n = 17) 1/4, Bilophila wadsworthia (n = 29) 0.5/1, and Clostridium spp. (n = 29) 0.125/0.5, respectively. MIC50 values (mg/l) for Bacteroides distasonis (n = 8) and Peptostreptococcus spp. (n = 9) were 0.25. The results indicated that moxifloxacin was almost as active as trovafloxacin, as active as gatifloxacin, and more active than levofloxacin and ciprofloxacin against the anaerobes tested.

In vitro activities of gatifloxacin, two other quinolones, and five nonquinolone antimicrobials against obligately anaerobic bacteria.

The activity of the new fluoroquinolone gatifloxacin was compared with those of other quinolones and antimicrobial agents of other classes against 294 anaerobes by the broth microdilution technique. For all strains tested, gatifloxacin MICs at which 50 and 90% of the isolates were inhibited were 0.5 and 2 mg/liter, respectively, and were 3 to 4 dilution steps lower than, e.g., ciprofloxacin.