Ligation of the cell surface receptor Fas/APO-1 (CD95) by its specific ligand or by anti-Fas antibodies rapidly induces apoptosis in susceptible cells. To characterize the molecular events involved in Fas-induced apoptosis, we examined the contribution of two subgroups of the mitogen-activated protein (MAP) kinase family, the Jun kinases or stress-activated protein kinases (JNKs/SAPKs) and the extracellular signal-regulated kinases (ERKs), in a Fas-sensitive neuroblastoma cell line. Here we show that both JNK and ERK protein kinases were activated upon Fas crosslinking through a Ras-dependent mechanism. Interference with either the JNK or ERK pathway by ectopic expression of dominant-interfering mutant proteins blocked Fas-mediated apoptosis. ERK activation was transient and associated with induced expression of the Fas receptor. In contrast, JNK activation was sustained and correlated with the onset of apoptosis. These data indicate that the ERK and the JNK groups of MAP kinases cooperate in the induction of cell death by Fas. Inhibition of Fas killing by an interleukin 1beta-converting enzyme (ICE)-like protease inhibitor peptide did not modify Fas-induced JNK activation upon Fas ligation. In contrast, changes in Bcl-2 level due to expression of sense and antisense vectors influenced the sensitivity to Fas killing and Fas-induced JNK activation.

The purpose of this study was to examine epidemiological trends of concussions among 15 different intercollegiate sports during the 1997-1998, 1998-1999, and 1999-2000 seasons. Data were collected using the National Collegiate Athletic Association (NCAA) Injury Surveillance System (ISS). For the 15 sports studied during the 3 academic years, the NCAA ISS documented 3,535 team-seasons, 40,547 reportable injuries, 5,566,924 practice athlete exposures (AEs), and 1,090,298 game AEs. Concussions accounted for 6.2% of all reported injuries during this 3-year study. Of all the reported injuries, women lacrosse players (13.9%) reported the highest percentage of suffering a concussion during a game followed by women's soccer (11.4%), men's ice hockey (10.3%), men's lacrosse (10.1%), football (8.8%), women's basketball, (8.5%), field hockey (7.2%), men's soccer (7.0%), wrestling (6.6%), men's basketball (5.0%), baseball (4.2%), and women's volleyball (4.1%). Female athletes from all 7 sports were found to be at a lower risk for suffering concussions during practice sessions than the 8 male sports. However, female athletes were found to be at a greater risk for suffering concussions during games compared to male athletes. Injury trends over the 3- year period indicate concussions continue to be on the rise for athletes participating in collegiate football, men's soccer, and women's and men's basketball.

When filtered alkaline extracts of pulverized bacteria of several varieties are precipitated with acid in the cold, boiled with acid, and all materials thrown down by these procedures removed, there remains a small amount of an alcohol-precipitable material which no longer gives any of the ordinary chemical reactions for proteins, such as the biuret, Hopkins-Cole, Millon, and sulfosalicylic acid reactions. The only protein reaction usually given by this material is a very weak xanthoproteic reaction. Nevertheless, the material, which is, as far as we can determine at present, free from coagulable protein, is specifically precipitable by homologous antiserum and gives specific complement fixation reactions. Such material can also be obtained from organisms like the influenza bacillus, pneumococcus, and meningococcus by extraction without preliminary grinding of the bacteria, and is present in filtrates of young and old broth cultures of the organisms. We believe that these acid- and heat-resistant antigenic materials are analogous to tuberculin and to the pneumococcus substances with which Dochez and Avery (6) made their observations some years ago. The stability of these substances is considerable and was investigated particularly because we thought this represented an indirect method of eliminating the possibility of their protein nature. In all cases boiling in a reflux condenser at an acid reaction ranging from pH 5 to 6 for 1 hour failed to destroy the antigenic specificity of the residue antigens. After such treatment satisfactory and specific precipitation reactions could be obtained. Similar boiling in alkaline reactions, however, destroyed the precipitability of staphylococcus and influenza residues. Subjected to autoclave digestion at an acid reaction of pH 5.4 for 1 hour at from three to four atmospheres, none of the antigenic residues investigated, except that obtained from the influenza bacillus, were destroyed. The pneumococcus and tubercle bacillus residue antigens were resistant to boiling for 1 hour, both in acid and alkaline reactions (pH 5.4 and 9.4). In fact, none of the procedures resorted to made any difference with these two last mentioned substances. It would seem that these facts would add considerable weight to the assumption that the materials dealt with were not ordinary whole proteins. On preservation in the ice box at an alkaline reaction of pH 9.4, the influenza residue deteriorated within 48 hours, but the other antigens withstood similar treatment for 6 days. In spite of the fact that these residue antigens were precipitable by homologous sera produced by immunization with the whole bacteria or their unfractionated extracts, we have so far failed to produce antibodies in animals by injecting these residues. While this may be due to inability to inject sufficient amounts of the material it still suggests strongly the possibility that we may be dealing with substances that are antigenic only in the sense that they are able to react with antibodies, but are themselves incapable of inciting antibody production. We suggest, in this connection, the possibility of the relationship between the power of antibody production and molecular size. This phase of the work is being continued on a more extensive scale. Our work on the reactions of the residue materials in infected animals indicates, as far as we have gone, that complete analogy exists in this respect between the conditions prevailing in guinea pigs infected with these organisms and those previously elucidated for tuberculous animals. This is in keeping with previous knowledge concerning the analogies between the mallein and tuberculin reactions and the studies on skin hypersusceptibility in Bacillus abortus- and typhoid-infected guinea pigs reported by Meyer and his coworkers. It would seem from all these facts that, in guinea pigs infected with bacteria capable of forming foci in the body, infection is followed within a variable, but relatively short time (5 days to 2 weeks) by a type of hypersusceptibility which is distinct from protein anaphylaxis and which may be determined by intradermal skin reaction. It appears likely that the growing bacteria elaborate in the animal body a metabolic product, possibly not a whole protein, which, though practically non-toxic to normal animals, may become highly and specifically injurious to the infected ones. Such a conception, if further confirmed, would lead to greater clearness in our comprehension of the toxic effects occurring in infections with organisms not true exotoxin producers and, judging by the cellular injuries observed in severe skin reactions, may easily explain focal necrosis and the deeper cellular degenerations observed in the course of many bacterial diseases. The general bearing of this work upon conceptions of hypersusceptibility is obvious and has been briefly discussed in another paper. Its chief significance is in holding out the hope that we may be able to elucidate the mechanism of a type of specific hypersusceptibility in which the antigen concerned is not a coagulable protein and in which the laws of sensitization in regard to time and quantity differ from those recognized in true protein anaphylaxis. It seems likely that a recognition of the fact that physical and chemical differences in the substances leading to various forms of specific hypersusceptibilities in the animal body must necessarily influence the mechanism of sensitization, may furnish a clue to further investigations. As such materials become simpler in structure, they fail to induce typical antibody production and by gradually increased diffusibility transfer the reactions from the cell surface to the interior of the cell. The extremes of the scale of differences would be represented by protein anaphylaxis, on the one hand, and drug idiosyncrasies, on the other. Although this suggestion is largely speculative, it has seemed worth mentioning as a line of reasoning suggested by our work. Incidentally, these studies may indicate the usefulness of the residue antigens for specific precipitation and complement fixation reactions for routine purposes in laboratory investigations.

We report here the first three-dimensional structure of the type 1 inositol 1,4,5-trisphosphate receptor (IP(3)R). From cryo-electron microscopic images of purified receptors embedded in vitreous ice, a three-dimensional structure was determined by use of standard single particle reconstruction techniques. The structure is strikingly different from that of the ryanodine receptor at similar resolution despite molecular similarities between these two calcium release channels. The 24 A resolution structure of the IP(3)R takes the shape of an uneven dumbbell, and is approximately 170 A tall. Its larger end is bulky, with four arms protruding laterally by approximately 50 A and, in comparison with the receptor topology, probably corresponds to the cytoplasmic domain of the receptor. The lateral dimension at the height of the protruding arms is approximately 155 A. The smaller end, whose lateral dimension is approximately 100 A, has structural features indicative of the membrane-spanning domain. A central opening in this domain, which is occluded on the cytoplasmic half, outlines a pathway for calcium flow in the open state of the channel.

The effects of the expression of the human Bcl-2 family proteins Bax, Bak, Bcl-2, and Bcl-XL were examined in the fission yeast Schizosaccharomyces pombe and compared with Bax-induced cell death in mammalian cells. Expression of the proapoptotic proteins Bax and Bak conferred a lethal phenotype in this yeast, which was strongly suppressed by coexpression of the anti-apoptotic protein Bcl-XL. Bcl-2 also partially abrogated Bax-mediated cytotoxicity in S. pombe, whereas a mutant of Bcl-2 (Gly145Ala) that fails to heterodimerize with Bax or block apoptosis in mammalian cells was inactive. However, other features distinguished Bax- and Bak-induced death in S. pombe from animal cell apoptosis. Electron microscopic analysis of S. pombe cells dying in response to Bax or Bak expression demonstrated massive cytosolic vacuolization and multifocal nuclear chromatin condensation, thus distinguishing this form of cell death from the classical morphological features of apoptosis seen in animal cells. Unlike Bax-induced apoptosis in 293 cells that led to the induction of interleukin-1 beta-converting enzyme (ICE)/CED-3-like protease activity, Bax- and Bak-induced cell death in S. pombe was accompanied neither by internucleosomal DNA fragmentation nor by activation of proteases with specificities similar to the ICE/CED-3 family. In addition, the baculovirus protease inhibitor p35, which is a potent inhibitor of ICE/CED-3 family proteases and a blocker of apoptosis in animal cells, failed to prevent cell death induction by Bax or Bak in fission yeast, whereas p35 inhibited Bax-induced cell death in mammalian cells. Taken together, these findings suggest that Bcl-2 family proteins may retain an evolutionarily conserved ability to regulate cell survival and death but also indicate differences in the downstream events that are activated by overexpression of Bax or Bak in divergent cell types.

We have characterized transcripts for nine major intrinsic proteins (MIPs), some of which function as water channels (aquaporins), from the ice plant Mesembryanthemum crystallinum. To determine the cellular distribution and expression of these MIPs, oligopeptide-based antibodies were generated against MIP-A, MIP-B, MIP-C, or MIP-F, which, according to sequence and functional characteristics, are located in the plasma membrane (PM) and tonoplast, respectively. MIPs were most abundant in cells involved in bulk water flow and solute flux. The tonoplast MIP-F was found in all cells, while signature cell types identified different PM-MIPs: MIP-A predominantly in phloem-associated cells, MIP-B in xylem parenchyma, and MIP-C in the epidermis and endodermis of immature roots. Membrane protein analysis confirmed MIP-F as tonoplast located. MIP-A and MIP-B were found in tonoplast fractions and also in fractions distinct from either the tonoplast or PM. MIP-C was most abundant but not exclusive to PM fractions, where it is expected based on its sequence signature. We suggest that within the cell, MIPs are mobile, which is similar to aquaporins cycling through animal endosomes. MIP cycling and the differential regulation of these proteins observed under conditions of salt stress may be fundamental for the control of tissue water flux.

McCDPK1 is a salinity- and drought-induced calcium-dependent protein kinase (CDPK) isolated from the common ice plant, Mesembryanthemum crystallinum. A yeast two-hybrid experiment was performed, using full-length McCDPK1 and truncated forms of McCDPK1 as baits, to identify interacting proteins. A catalytically impaired bait isolated a cDNA clone encoding a novel protein, CDPK substrate protein 1 (CSP1). CSP1 interacted with McCDPK1 in a substrate-like fashion in both yeast two-hybrid assays and wheat germ interaction assays. Furthermore, McCDPK1 was capable of phosphorylating CSP1 in vitro in a calcium-dependent manner. Our results demonstrate that the use of catalytically impaired and unregulated CDPKs with the yeast two-hybrid system can accelerate the discovery of CDPK substrates. The deduced CSP1 amino acid sequence indicated that it is a novel member of a class of pseudo-response regulator-like proteins that have a highly conserved helix-loop-helix DNA binding domain and a C-terminal activation domain. McCDPK1 and CSP1 co-localized to nuclei of NaCl-stressed ice plants. Csp1 transcript accumulation was not regulated by NaCl or dehydration stress. Our results strongly suggest that McCDPK1 may regulate the function of CSP1 by reversible phosphorylation.

When proteins of whole Drosophila thorax were analyzed by two-dimensional gel electrophoresis, 186 spots were detected by protein staining with Coomassie brilliant blue R-250. Two methods were developed to identify proteins which exist in indirect flight muscle (IFM) and its myofibrils. 1) A whole fly was freeze-dried in a dry ice-acetone mixture, and indirect flight muscle fibers were cleanly dissected out from the thorax. The muscle cells and the rest of the thorax were analyzed separately. The muscle contained 146 polypeptides, of which 12 were not detected elsewhere. 2) Flies were frozen in liquid nitrogen and shaken vigorously so that their thoraces broke off from heads and abdomens. The thoraces were separated from the rest by sieving and centrifugation. After homogenization of the thorax, myofibrils were prepared by centrifugation in a discontinuous sucrose density gradient. The myofibril fraction contained at least 20 proteins. There were two types of actin (II and III), myosin heavy chain, tropomyosin and paramyosin. Nine of the other myofibrillar proteins were specific to this muscle.

The alkenone-pCO2 methodology has been used to reconstruct the partial pressure of ancient atmospheric carbon dioxide (pCO2) for the past 45 million years of Earth's history (Middle Eocene to Pleistocene epochs). The present long-term CO2 record is a composite of data from multiple ocean localities that express a wide range of oceanographic and algal growth conditions that potentially bias CO2 results. In this study, we present a pCO2 record spanning the past 40 million years from a single marine locality, Ocean Drilling Program Site 925 located in the western equatorial Atlantic Ocean. The trends and absolute values of our new CO2 record site are broadly consistent with previously published multi-site alkenone-CO2 results. However, new pCO2 estimates for the Middle Miocene are notably higher than published records, with average pCO2 concentrations in the range of 400-500 ppm. Our results are generally consistent with recent pCO2 estimates based on boron isotope-pH data and stomatal index records, and suggest that CO2 levels were highest during a period of global warmth associated with the Middle Miocene Climatic Optimum (17-14 million years ago, Ma), followed by a decline in CO2 during the Middle Miocene Climate Transition (approx. 14 Ma). Several relationships remain contrary to expectations. For example, benthic foraminiferal δ(18)O records suggest a period of deglaciation and/or high-latitude warming during the latest Oligocene (27-23 Ma) that, based on our results, occurred concurrently with a long-term decrease in CO2 levels. Additionally, a large positive δ(18)O excursion near the Oligocene-Miocene boundary (the Mi-1 event, approx. 23 Ma), assumed to represent a period of glacial advance and retreat on Antarctica, is difficult to explain by our CO2 record alone given what is known of Antarctic ice sheet history and the strong hysteresis of the East Antarctic Ice Sheet once it has grown to continental dimensions. We also demonstrate that in the Neogene with low CO2 levels, algal carbon concentrating mechanisms and spontaneous biocarbonate-CO2 conversions are likely to play a more important role in algal carbon fixation, which provides a potential bias to the alkenone-pCO2 method.

Vertical wind shear and concentration gradients of viable, airborne bacteria were used to calculate the upward flux of viable cells above bare soil and canopies of several crops. Concentrations at soil or canopy height varied from 46 colony-forming units per m over young corn and wet soil to 663 colony-forming units per m over dry soil and 6,500 colony-forming units per m over a closed wheat canopy. In simultaneous samples, concentrations of viable bacteria in the air 10 m inside an alfalfa field were fourfold higher than those over a field with dry, bare soil immediately upwind. The upward flux of viable bacteria over alfalfa was three- to fourfold greater than over dry soil. Concentrations of ice nucleation-active bacteria were higher over plants than over soil. Thus, plant canopies may constitute a major source of bacteria, including ice nucleation-active bacteria, in the air.

OBJECTIVE

To describe the treatment of knee pain in older adults in primary care and to compare reported practice with published evidence.

METHODS

A semi-structured interview of older adults with knee pain about their use of 26 interventions for knee pain.

RESULTS

201 adults were interviewed. A median of six interventions had been advised for each participant, with heat and ice (84%) the most frequently advised, followed by paracetamol (71%), compound opioid analgesics (59%) and non-selective non-steroidal anti-inflammatory drugs (59%). Three core treatments for knee pain (written information, exercise and weight loss) were advised to 16%, 46% and 39% of the participants, respectively. Half of the interventions had been initiated through 'self care'. Most core treatments had not been initiated before second-line interventions had been used, paracetamol being the exception. Referral to surgery was commonly initiated before more conservative options had been tried.

CONCLUSIONS

Interventions recommended as core treatment for knee pain in older adults were underused-in particular, exercise, weight loss and the provision of written information. There appeared to be early reliance on pharmacological treatments with underuse of non-pharmacological interventions in early treatment choices. Self care played an important role in the management of this condition. The study provides clear evidence on the need to improve the delivery of core treatments for osteoarthritis and highlights the need to support and encourage self care.

Perennially cold habitats are diminishing as a result of climate change; however, little is known of the diversity or biogeography of microbes that thrive in such environments. Here we use targeted 16S rRNA gene surveys to evaluate the global affinities of cold-dwelling cyanobacteria from lake, stream and ice communities living at the northern limit of High Arctic Canada. Pigment signature analysis by HPLC confirmed the dominance of cyanobacteria in the phototrophic communities of these High Arctic microbial mats, with associated populations of chlorophytes and chromophytes. Microscopic analysis of the cyanobacteria revealed a diverse assemblage of morphospecies grouping into orders Oscillatoriales, Nostocales and Chroococcales. The 16S rRNA gene sequences from six clone libraries grouped into a total of 24 ribotypes, with a diversity in each mat ranging from five ribotypes in ice-based communities to 14 in land-based pond communities. However, no significant differences in composition were observed between these two microbial mat systems. Based on clone-library and phylogenetic analysis, several of the High Arctic ribotypes were found to be >99% similar to Antarctic and alpine sequences, including to taxa previously considered endemic to Antarctica. Among the latter, one High Arctic sequence was found 99.8% similar to Leptolyngbya antarctica sequenced from the Larsemann Hills, Antarctica. More than 68% of all identified ribotypes at each site matched only cyanobacterial sequences from perennially cold terrestrial ecosystems, and were <97.5% similar to sequences from warmer environments. These results imply the global distribution of low-temperature cyanobacterial ecotypes throughout the cold terrestrial biosphere.

BACKGROUND

Field triage criteria for trauma patients results in over-triage rates of 30% to 50% to achieve under-triage rates of 10%. This large number of patients may stress trauma center resources. Elevated arterial lactate (ALAC) levels have been shown to be a marker of serious injury but the need for arterial sampling limits the utility of the determination. The goal of this study was: 1) to determine the correlation between venous lactate (VLAC) and ALAC; 2) to determine whether VLAC could identify those patients with serious injuries; and 3) to compare an elevated VLAC level against standard triage criteria (STC) in their ability to identify major injury.

METHODS

Arterial and venous samples for blood gas and lactate analyses were obtained in 375 patients within 10 minutes of patient arrival to the trauma center. Arterial and venous samples were drawn within 2 minutes of each other, placed on ice, and analyzed within 10 minutes of sampling. The location of sampling was left to physician discretion. Data collected included injury mechanism, demographics, admission vital signs, emergency department disposition, length of stay, and injury severity scores (ISS). Admission to the ICU, need for emergency operation, length of stay, and death were noted. Emergency medical service staff were queried to determine which standard triage criteria (STC) were fulfilled.

RESULTS

The mean ALAC was 3.11 mmol/L (SD 3.45, 95% confidence interval [CI] 2.67 to 3.55) and mean VLAC was 3.43 mmol/L (SD 3.41, 95% CI 2.96 to 3.90). There was no significant difference between ALAC and VLAC. The correlation between ALAC and VLAC was 0.94 (95% CI 0.94 to 0.96, p = 0.0001). An elevated VLAC predicted moderate to severe injury and there was a significant association between an increased lactate and maximum Abbreviated Injury Score (AIS) of 4 and 5 (ANOVA, F = 8.26, p < 0.001). Patients with VLAC>> or =2 mmol/L had significantly increased relative risks of ISS>> or = 13, death, admission to the ICU, and length of stay>> 2 days. In comparison with STC, a VLAC>> or = 2 mmol/L decreased undertriage in patients with ISS>> or = 13 by one half (11% versus 24%) for patients with ISS>> or = 13 and decreased over-triage by 28% (46% versus 64%). These data were most pronounced for patients injured in motor vehicle collisions.

CONCLUSIONS

VLAC is an excellent approximation for ALAC. A VLAC>> or = 2 mmol/L appears to predict an ISS>> or = 13, the need for ICU resources, and prolonged hospital stays. VLAC was significantly better than STC in all patients and was most useful in victims of blunt trauma, especially motor vehicle collisions.

While ice and compression wraps are commonly used to treat musculoskeletal injuries, the literature describing intramuscular temperatures has not addressed the combination of ice and compression wraps. The purpose of this study was to evaluate intramuscular temperatures at three sites on the anterior thigh (skin surface, 1 cm below the fat layer, and 2 cm below the fat layer) using both ice and compression wraps. Temperatures were recorded in 11 subjects with an isothermex, using implantable and surface thermocouples. Each subject was tested under four conditions: control, compression only, ice only, and ice + compression according to a balanced Latin square. Surface and intramuscular temperatures were recorded at 30 second intervals during 5 minutes of preapplication, 30 minutes application, and 20 minutes postapplication. A repeated measures ANOVA and Duncan post hoc tests were used to evaluate peak temperature differences between the treatment conditions and the depths of measurement. Both ice alone and ice + compression produced significant cooling at all three depths (F(6,60) = 168.5, p<.0005). Likewise, during the 20-minute postapplication period, these temperatures did not return to their preapplication levels. The compression-only condition produced significant warming at the skin surface, but did not have any effect on intramuscular temperature. At all depths, the ice + compression condition produced significantly cooler temperatures than ice alone. We suggest that compression increases the effectiveness of ice in reducing tissue temperatures. Therefore, ice combined with compression should be more effective than ice alone in reducing the metabolism of injured tissue. This provides an additional rationale for combining ice with compression in treating acute musculoskeletal injuries.

BACKGROUND

Hockey is one of the top sports for participation in youth in Canada. There are limited data on the epidemiology of injury in youth hockey.

OBJECTIVE

Through implementation and validation of an injury surveillance system, youth ice hockey injury rates, risk factors, and mechanisms of injury will be examined.

METHODS

Descriptive epidemiology study.

METHODS

During the 2004-2005 season in minor hockey in Calgary, Alberta, Canada, 71 hockey teams (N = 986) were studied, including teams from each age group (Atom, 9/10 years; Pee Wee, 11/12 years; Bantam, 13/14 years; Midget, 15/16 years) and division of play (7-10 divisions per age group). A certified athletic therapist or candidate did weekly assessments of any identified hockey injury. Injury definition included any injury occurring during the regular hockey season that required medical attention, removal from a session, or missing a subsequent session.

RESULTS

Of the 986 participating players, 216 players sustained a total of 296 injuries in the 2004-2005 season. The overall injury rate was 30.02 injuries per 100 players per season (95% confidence interval, 27.17-32.99) or 4.13 injuries per 1000 player hours (95% confidence interval, 3.67-4.62). Forty-five percent of all injuries occurred during body checking. Compared with the youngest age group, Atom, the risk of injury was greater in Pee Wee (relative risk, 2.97; 95% confidence interval, 1.63-5.8), Bantam (relative risk, 3.72; 95% confidence interval, 2.08-7.14), and Midget (relative risk, 5.43; 95% confidence interval, 3.14-10.17) leagues. The risk of injury in Pee Wee was greatest in the most elite divisions (relative risk, 2.45; 95% confidence interval, 1.15-5.81). Concussion, shoulder sprain/dislocation, and knee sprain were the most common injuries.

CONCLUSIONS

Significant differences in injury rates were found by age and division of play. The public health significance of body checking injury in minor hockey is great. Future research will include expansion of surveillance to further examine body checking injuries and prevention strategies in minor hockey.

Using in silico methods for screening the human genome for new caspase recruitment domain (CARD) proteins, we have identified INCA (Inhibitory CARD) as a protein that shares 81% identity with the prodomain of caspase-1. The INCA gene is located on chromosome 11q22 between the genes of COP/Pseudo-ICE and ICEBERG, two other CARD proteins that arose from caspase-1 gene duplications. We show that INCA mRNA is expressed in many tissues. INCA is specifically upregulated by interferon-gamma in the monocytic cell lines THP-1 and U937. INCA physically interacts with procaspase-1 and blocks the release of mature IL-1beta from LPS-stimulated macrophages. Unlike COP/Pseudo-ICE and procaspase-1, INCA does not interact with RIP2 and does not induce NF-kappaB activation. Our data show that INCA is a novel intracellular regulator of procaspase-1 activation, involved in the regulation of pro-IL-1beta processing and its release during inflammation.

OBJECTIVE

Parallel magnetic resonance imaging (MRI) requires an array of RF coil elements with different sensitivity distributions and with minimal electromagnetic coupling. The goal of this project was to develop a new method based on induced current compensation or elimination (ICE) for improved coil element decoupling and to investigate its performance in phantom MR images.

METHODS

An electromagnetic decoupling method based on induced current compensation or elimination for nonoverlapping RF coil arrays was developed with the design criteria of high efficiency, easy implementation, and no physical connection to RF array elements. An eigenvalue/eigenvector approach was employed to analyze the decoupling mechanism and condition. A two-channel microstrip array and an eight-channel coil array were built to test the performance of the method. Following workbench tests, MR imaging experiments were performed on a 7T MR scanner.

RESULTS

The bench tests showed that both arrays achieved sufficient decoupling with a S21 less than -25 dB among the coil elements at 298 MHz. The MR phantom images demonstrated well-defined sensitivity distributions from each coil element and the unique decoupling capability of the proposed ICE decoupling technique. B1 distributions of the individual elements were also measured and calculated.

CONCLUSIONS

The theoretical analysis and experiments demonstrated the feasibility of the decoupling method for high field RF coil array designs without overlapping or direct physical connections between coil elements, which provide more flexibility for coil array design and optimization. The method offers a new approach to address the RF array decoupling issue, which is a major challenge in implementing parallel imaging.

Shigella, the etiological agent of bacillary dysentery, rapidly kills human monocyte-derived macrophages in vitro. Wild-type Shigella flexneri, but not a nonvirulent derivative, induced human macrophage apoptosis as determined by morphology and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL). Shigella-mediated macrophage cell death was blocked by the peptide inhibitors of caspases, acetyl-Tyr-Val-Ala-Asp-aldehyde (acetyl-YVAD-CHO) and acetyl-Tyr-Val-Ala-Asp-chloromethylketone (acetyl-YVAD-CMK). Protection from apoptosis by YVAD was observed in monocytes matured in the presence or absence of colony-stimulating factors (CSF) like macrophage-CSF or granulocyte-macrophage-CSF. Furthermore, lipopolysaccharide (LPS) or gamma interferon (IFN-gamma) rendered human macrophages partially resistant to Shigella cytotoxicity. Macrophages stimulated with either LPS or IFN-gamma were also protected by YVAD from Shigella-induced cell death. During Shigella infections of human macrophages, interleukin-1beta (IL-1beta) was cleaved to the mature form. IL-1beta maturation was severely retarded by YVAD, indicating that IL-1beta-converting enzyme (ICE; caspase 1) is activated in Shigella-induced apoptosis. The finding that Shigella induces apoptosis in human macrophages by activating ICE supports the hypothesis that the acute inflammation characteristic of shigellosis is initially triggered by apoptotic macrophages which release mature IL-1beta during programmed cell death.

Proteins which produce a thermal hysteresis (i.e. lower the freezing point of water below the melting point) are common antifreezes in cold adapted poikilothermic animals, especially fishes from ice-laden seas and terrestrial arthropods. However, these proteins have not been previously identified in plants. 16 species of plants collected from northern Indiana in autumn and winter had low levels of thermal hysteresis activity, but activity was absent in summer. This suggests that thermal hysteresis proteins may be a fairly common winter adaptation in angiosperms. Winter stem fluid from the bittersweet nightshade, Solanum dulcamara L., also showed the recrystallization inhibition activity characteristic of the animal thermal hysteresis proteins (THPs), suggesting a possible function for the THPs in this freeze tolerant species. Other potential functions are discussed. Antibodies to an insect THP cross reacted on immunoelectroblots with proteins in S. dulcamara stem fluid, indicating common epitopes in the insect and plant THPs.

The ability of several water models to predict the properties of ices is discussed. The emphasis is put on the results for the densities and the coexistence curves between the different ice forms. It is concluded that none of the most commonly used rigid models is satisfactory. A new model specifically designed to cope with solid-phase properties is proposed. The parameters have been obtained by fitting the equation of state and selected points of the melting lines and of the coexistence lines involving different ice forms. The phase diagram is then calculated for the new potential. The predicted melting temperature of hexagonal ice (Ih) at 1 bar is 272.2 K. This excellent value does not imply a deterioration of the rest of the properties. In fact, the predictions for both the densities and the coexistence curves are better than for TIP4P, which previously yielded the best estimations of the ice properties.

The Southern Ocean houses a diverse and productive community of organisms. Unicellular eukaryotic diatoms are the main primary producers in this environment, where photosynthesis is limited by low concentrations of dissolved iron and large seasonal fluctuations in light, temperature and the extent of sea ice. How diatoms have adapted to this extreme environment is largely unknown. Here we present insights into the genome evolution of a cold-adapted diatom from the Southern Ocean, Fragilariopsis cylindrus, based on a comparison with temperate diatoms. We find that approximately 24.7 per cent of the diploid F. cylindrus genome consists of genetic loci with alleles that are highly divergent (15.1 megabases of the total genome size of 61.1 megabases). These divergent alleles were differentially expressed across environmental conditions, including darkness, low iron, freezing, elevated temperature and increased CO2. Alleles with the largest ratio of non-synonymous to synonymous nucleotide substitutions also show the most pronounced condition-dependent expression, suggesting a correlation between diversifying selection and allelic differentiation. Divergent alleles may be involved in adaptation to environmental fluctuations in the Southern Ocean.

Ice, which has been described as the drug of the 1990s, is a pure form of (+)methamphetamine hydrochloride; it is more dangerous because of its purity and because it can be inhaled. Taken by this route, the drug causes an effect similar to that from an intravenous dose, and much more intense than that from ingestion. The detailed mechanism of action differs from that of cocaine, but the overall stimulant effect of methamphetamine is similar. Methamphetamine effects, however, persist for hours, whereas cocaine effects are over in minutes. Ice is, therefore, just another agent for abuse by those seeking psychostimulation and, as with cocaine, compulsive abusers of amphetamines consume the drug repeatedly and continuously. Unlike cocaine, methamphetamine is a synthetic compound and is manufactured in illicit laboratories within the United States.

BACKGROUND

Identification of high-risk sports, including their most common and severe injuries and illnesses, will facilitate the identification of sports and athletes at risk at an early stage.

OBJECTIVE

To analyse the frequencies and characteristics of injuries and illnesses during the XXI Winter Olympic Games in Vancouver 2010.

METHODS

All National Olympic Committees' (NOC) head physicians were asked to report daily the occurrence (or non-occurrence) of newly sustained injuries and illnesses on a standardised reporting form. In addition, the medical centres at the Vancouver and Whistler Olympic clinics reported daily on all athletes treated for injuries and illnesses.

RESULTS

Physicians covering 2567 athletes (1045 females, 1522 males) from 82 NOCs participated in the study. The reported 287 injuries and 185 illnesses resulted in an incidence of 111.8 injuries and 72.1 illnesses per 1000 registered athletes. In relation to the number of registered athletes, the risk of sustaining an injury was highest for bobsleigh, ice hockey, short track, alpine freestyle and snowboard cross (15-35% of registered athletes were affected in each sport). The injury risk was lowest for the Nordic skiing events (biathlon, cross country skiing, ski jumping, Nordic combined), luge, curling, speed skating and freestyle moguls (less than 5% of registered athletes). Head/cervical spine and knee were the most common injury locations. Injuries were evenly distributed between training (54.0%) and competition (46.0%; p=0.18), and 22.6% of the injuries resulted in an absence from training or competition. In skeleton, figure and speed skating, curling, snowboard cross and biathlon, every 10th athlete suffered from at least one illness. In 113 illnesses (62.8%), the respiratory system was affected.

CONCLUSIONS

At least 11% of the athletes incurred an injury during the games, and 7% of the athletes an illness. The incidence of injuries and illnesses varied substantially between sports. Analyses of injury mechanisms in high-risk Olympic winter sports are essential to better direct injury-prevention strategies.

Two independent cross-sectional dietary surveys (the Individual and National Food Consumption Surveys, INCA), performed in 1998-99 (INCA1) and in 2006-07 (INCA2) on nationally representative samples of French people, were used to analyse trends in the dietary habits and nutritional intake of French adults. Food consumption was recorded through 7-d dietary records, and nutritional intakes were assessed using the French food composition database. After exclusion of under-reporters, analyses were performed on 3267 adults, aged 18-79 years: 1345 from INCA1 and 1922 from INCA2. The trends highlighted over the 8-year period showed a decrease in consumption of dairy products, meat, bread, potatoes, pastries/croissant-like pastries/cakes/biscuits and sugar/confectionery. In contrast, the consumption of fruits and vegetables, rice, ice cream and chocolate increased. Other food groups, like fish and snacking foods, remained stable. Food choices were mostly age specific. These age differences remained consistent over the years and underlined two opposite dietary trends: a 'traditional' one mainly followed by the elderly, and a 'snacking and convenience' one mainly adopted by young adults. The overall trends in food consumption did not influence the mean energy intake, but did slightly modify the contribution of each macronutrient to energy intake. These repeated surveys highlighted the fact that trends in French food habits have moved towards an average European diet at the crossroads between Mediterranean and Northern diets, and that food consumption changes impacted, to a lesser extent, nutritional intake.