The role of past climatic change in shaping the distributions of tropical rain forest vertebrates is central to long-standing hypotheses about the legacy of the Quaternary ice ages. One approach to testing such hypotheses is to use genetic data to infer the demographic history of codistributed species. Population genetic theory that relates the structure of allelic genealogies to historical changes in effective population size can be used to detect a past history of demographic expansion or contraction. The fruit bats Cynopterus sphinx and C. brachyotis (Chiroptera: Pteropodidae) exhibit markedly different distribution patterns across the Indomalayan region and therefore represent an exemplary species pair to use for such tests. The purpose of this study was to test alternative hypotheses about historical patterns of demographic expansion and contraction in C. sphinx and C. brachyotis using a coalescent-based analysis of microsatellite variation. Specifically, we used a hierarchical Bayesian model based on Markov chain Monte Carlo simulations to estimate the posterior distribution of genealogical and demographic parameters. The results revealed strong evidence for population contraction in both species. Evidence for a population contraction in C. brachyotis was expected on the basis of biogeographic considerations. However, similar evidence for population contraction in C. sphinx does not support the hypothesis that this species underwent a pronounced range expansion during the late Quaternary. Genetic evidence for population decline may reflect the consequences of habitat destruction on a more recent time scale.

The use of cryotherapy, i.e. the application of cold for the treatment of injury or disease, is widespread in sports medicine today. It is an established method when treating acute soft tissue injuries, but there is a discrepancy between the scientific basis for cryotherapy and clinical studies. Various methods such as ice packs, ice towels, ice massage, gel packs, refrigerant gases and inflatable splints can be used. Cold is also used to reduce the recovery time as part of the rehabilitation programme both after acute injuries and in the treatment of chronic injuries. Cryotherapy has also been shown to reduce pain effectively in the post-operative period after reconstructive surgery of the joints. Both superficial and deep temperature changes depend on the method of application, initial temperature and application time. The physiological and biological effects are due to the reduction in temperature in the various tissues, together with the neuromuscular action and relaxation of the muscles produced by the application of cold. Cold increases the pain threshold, the viscosity and the plastic deformation of the tissues but decreases the motor performance. The application of cold has also been found to decrease the inflammatory reaction in an experimental situation. Cold appears to be effective and harmless and few complications or side-effects after the use of cold therapy are reported. Prolonged application at very low temperatures should, however, be avoided as this may cause serious side-effects, such as frost-bite and nerve injuries. Practical applications, indications and contraindications are discussed.

The net proton-hydroxyl permeability of large unilamellar liposomes has been measured by an acid-base pulse titration technique and has been determined to be several orders of magnitude greater than that measured for other monovalent ions. This permeability is relatively insensitive to variations in lipid composition. Proton permeability and hydroxyl permeability vary with pH 6 to 8, and this variation can occur in the absence of alterations in surface charge density resulting from titrations of acidic and basic groups on the lipids. In order to account for the exceptionally high proton-hydroxyl permeability with respect to other monovalent ions, we propose that protons or hydroxyls or both interact with clusters of hydrogen-bonded water molecules in the lipid bilayer, such that they are transferred across the bilayer by rearrangement of hydrogen bonds in a manner similar to their transport in water and ice.

The quick-freeze, deep-etch, rotary-replication technique is useful for visualizing cells and cell fractions but does not work with suspensions of macromolecules. These inevitably clump or collapse during deep-etching, presumably due to surface tension forces that develop during their transfer from ice to vacuum. Previous protocols have attempted to overcome such forces by attaching macromolecules to freshly cleaved mica before drying and replication. I describe here an adaptation of this procedure to the deep-etch technique as otherwise practiced. My innovation is to mix the molecules with an aqueous suspension of tiny flakes of mica and then to quick-freeze and freeze-fracture the suspension exactly as if one were dealing with cells. The fracture inevitably strikes the surfaces of many mica flakes and thereby cleaves the adsorbed macromolecules cleanly enough to reveal interesting substructure within them. The subsequent step of deep-etching exposes large expanses of unfractured mica and thus reveals intact macromolecules. These macromolecules are not obscured by salt deposits, even if they were frozen in hypertonic solutions, apparently because the fracturing step removes nearly all of the overlying electrolyte. Moreover, these macromolecules are minimally freeze-dried (since exposure is sufficient after only 3 min of etching at -102 degrees C) so they retain their three-dimensional topology. I show that molluscan hemocyanin is a good internal standard for this new technique. It is available commercially in stable solutions, mixes well with all sizes of macromolecules, and consists of particles that display distinct five-start surface helices, which have been measured carefully in the past and which possess a known handedness, useful for determining the orientation of micrographs when examining the various helical patterns possessed by most types of extended macromolecules. The fractured hemocyanin particles also display characteristic internal structures, which permit determination of the elevation of the "molecular cleavage" described above. Finally, molluscan hemocyanin is delicate enough to reflect bad freezing or poor replication, if these steps become a problem. A survey of several macromolecules is presented, including soluble enzymes, antibodies, filamentous proteins and nucleoproteins. These images, for the most part, correspond to those previously obtained by negative staining. New details of their structures are noted, and the images are used to illustrate both the advantages and drawbacks of the new procedure.

Four distinct macromolecular antifreezes have been isolated and characterized from different marine fish. These include the glycoprotein antifreezes (Mr 2.5-33 K), which are made up of a repeating tripeptide (Ala-Ala-Thr)n with a disaccharide attached to the threonyl residues, and three antifreeze protein (AFP) types. Type I is an alanine-rich, amphiphilic, alpha-helix (Mr 3-5 K); type II is a larger protein (Mr 14 K) with a high content of reverse turns and five disulfide bridges; and type III is intermediate in size (Mr 6-7 K) with no distinguishing features of secondary structure or amino acid composition. Despite their marked structural differences, all four antifreeze types appear to function in the same way by binding to the prism faces of ice crystals and inhibiting growth along the a-axes. It is suggested that type I AFP binds preferentially to the prism faces as a result of interactions between the helix macrodipole and the dipoles on the water molecules in the ice lattice. Binding is stabilized by hydrogen bonding, and the amphiphilic character of the helix results in the hydrophobic phase of the helix being exposed to the solvent. When the solution temperature is lowered further, ice crystal growth occurs primarily on the uncoated, unordered basal plane resulting in bipyramidal-shaped crystals. The structural features of type I AFP that could contribute to this mechanism of action are reviewed. Current challenges lie in solving the other antifreeze structures and interpreting them in light of what appears to be a common mechanism of action.

This review introduces the subjects of bacterial biodiversity and biogeography. Studies of biogeography are important for understanding biodiversity, the occurrence of threatened species, and the ecological role of free-living and symbiotic prokaryotes. A set of postulates is proposed for biogeography as a guide to determining whether prokaryotes are "cosmopolitan" (found in more than one geographic location on Earth) or candidate endemic species. The term "geovar" is coined to define a geographical variety of prokaryote that is restricted to one area on Earth or one host species. This review discusses sea ice bacteriology as a test case for examining bacterial diversity and biogeography. Approximately 7% of Earth's surface is covered by sea ice, which is colonized principally by psychrophilic microorganisms. This extensive community of microorganisms, referred to as the sea ice microbial community (SIMCO), contains algae (mostly diatoms), protozoa, and bacteria. Recent investigations indicate that the sea ice bacteria fall into four major phylogenetic groups: the proteobacteria, the Cytophaga-Flavobacterium-Bacteroides (CFB) group, and the high and low mol percent gram-positive bacteria. Archaea associated with sea ice communities have also been reported. Several novel bacterial genera and species have been discovered, including Polaromonas, Polaribacter, Psychroflexus, Gelidibacter, and Octadecabacter; many others await study. Some of the gram-negative sea ice bacteria have among the lowest maximum temperatures for growth known, < 10 degrees C for some strains. The polar sea ice environment is an ideal habitat for studying microbial biogeography because of the dispersal issues involved. Dispersal between poles is problematic because of the long distances and the difficulty of transporting psychrophilic bacteria across the equator. Studies to date indicate that members of some genera occur at both poles; however, cosmopolitan species have not yet been discovered. Additional research on polar sea ice bacteria is needed to resolve this issue and extend our understanding of its microbial diversity.

Salvage of patients with relapsed and refractory Hodgkin disease (HD) with high-dose chemoradiotherapy (HDT) and autologous stem cell transplantation (ASCT) results in event-free survival (EFS) rates from 30% to 50%. Unfortunately, the reduction in toxicity associated with modern supportive care has improved EFS by only 5% to 10% and has not reduced the relapse rate. Results of a comprehensive 2-step protocol encompassing dose-dense and dose-intense second-line chemotherapy, followed by HDT and ASCT, are reported. Sixty-five consecutive patients, 22 with primary refractory HD and 43 with relapsed HD, were treated with 2 biweekly cycles of ifosfamide, carboplatin, and etoposide (ICE). Peripheral blood progenitor cells from responding patients were collected, and the patients were given accelerated fractionation involved field radiotherapy (IFRT) followed by cyclophosphamide-etoposide and either intensive accelerated fractionation total lymphoid irradiation or carmustine and ASCT. The EFS rate at a median follow-up of 43 months, as analyzed by intent to treat, was 58%. The response rate to ICE was 88%, and the EFS rate for patients who underwent transplantation was 68%. Cox regression analysis identified 3 factors before the initiation of ICE that predicted for outcome: B symptoms, extranodal disease, and complete remission duration of less than 1 year. EFS rates were 83% for patients with 0 to 1 adverse factors, 27% for patients with 2 factors, and 10% for patients with 3 factors (P <.001). These results compare favorably with other series and document the feasibility and efficacy of giving uniform dose-dense and dose-intense cytoreductive chemotherapy and integrating accelerated fractionation radiotherapy into an ASCT treatment program. This prognostic model provides a basis for risk-adapted HDT.

OBJECTIVE

Apoptosis is a form of programmed cell death seen in a variety of developmental and disease states, including traumatic injuries. The main objective of this study was to determine whether apoptosis is observed after human spinal cord injury (SCI). The spatial and temporal expression of apoptotic cells as well as the nature of the cells involved in programmed cell death were also investigated.

METHODS

The authors examined the spinal cords of 15 patients who died between 3 hours and 2 months after a traumatic SCI. Apoptotic cells were found at the edges of the lesion epicenter and in the adjacent white matter, particularly in the ascending tracts, by using histological (cresyl violet, hematoxylin and eosin) and nuclear staining (Hoechst 33342). The presence of apoptotic cells was supported by staining with the terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick-end labeling technique and confirmed by immunostaining for the processed form of caspase-3 (CPP-32), a member of the interleukin-1beta-converting enzyme/Caenorhabditis elegans D 3 (ICE/CED-3) family of proteases that plays an essential role in programmed cell death. Apoptosis in this series of human SCIs was a prominent pathological finding in 14 of the 15 spinal cords examined when compared with five uninjured control spinal cords. To determine the type of cells undergoing apoptosis, the authors immunostained specimens with a variety of antibodies, including glial fibrillary acidic protein, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase), and CD45/68. Oligodendrocytes stained with CNPase and a number of apoptotic nuclei colocalized with positive staining for this antibody.

CONCLUSIONS

These results support the hypothesis that apoptosis occurs in human SCIs and is accompanied by the activation of caspase-3 of the cysteine protease family. This mechanism of cell death contributes to the secondary injury processes seen after human SCI and may have important clinical implications for the further development of protease inhibitors to prevent programmed cell death.

Sea-surface warming, sea-ice melting and related freshening, changes in circulation and mixing regimes, and ocean acidification induced by the present climate changes are modifying marine ecosystem structure and function and have the potential to alter the cycling of carbon and nutrients in surface oceans. Changing climate has direct and indirect consequences on marine viruses, including cascading effects on biogeochemical cycles, food webs, and the metabolic balance of the ocean. We discuss here a range of case studies of climate change and the potential consequences on virus function, viral assemblages and virus-host interactions. In turn, marine viruses influence directly and indirectly biogeochemical cycles, carbon sequestration capacity of the oceans and the gas exchange between the ocean surface and the atmosphere. We cannot yet predict whether the viruses will exacerbate or attenuate the magnitude of climate changes on marine ecosystems, but we provide evidence that marine viruses interact actively with the present climate change and are a key biotic component that is able to influence the oceans' feedback on climate change. Long-term and wide spatial-scale studies, and improved knowledge of host-virus dynamics in the world's oceans will permit the incorporation of the viral component into future ocean climate models and increase the accuracy of the predictions of the climate change impacts on the function of the oceans.

Antifreeze proteins are found in a wide range of overwintering plants where they inhibit the growth and recrystallization of ice that forms in intercellular spaces. Unlike antifreeze proteins found in fish and insects, plant antifreeze proteins have multiple, hydrophilic ice-binding domains. Surprisingly, antifreeze proteins from plants are homologous to pathogenesis-related proteins and also provide protection against psychrophilic pathogens. In winter rye (Secale cereale), antifreeze proteins accumulate in response to cold, short daylength, dehydration and ethylene, but not pathogens. Transferring single genes encoding antifreeze proteins to freezing-sensitive plants lowered their freezing temperatures by approximately 1 degrees C. Genes encoding dual-function plant antifreeze proteins are excellent models for use in evolutionary studies to determine how genes acquire new expression patterns and how proteins acquire new activities.

Titanium and iron concentration data from the anoxic Cariaco Basin, off the Venezuelan coast, can be used to infer variations in the hydrological cycle over northern South America during the past 14,000 years with subdecadal resolution. Following a dry Younger Dryas, a period of increased precipitation and riverine discharge occurred during the Holocene "thermal maximum." Since approximately 5400 years ago, a trend toward drier conditions is evident from the data, with high-amplitude fluctuations and precipitation minima during the time interval 3800 to 2800 years ago and during the "Little Ice Age." These regional changes in precipitation are best explained by shifts in the mean latitude of the Atlantic Intertropical Convergence Zone (ITCZ), potentially driven by Pacific-based climate variability. The Cariaco Basin record exhibits strong correlations with climate records from distant regions, including the high-latitude Northern Hemisphere, providing evidence for global teleconnections among regional climates.

Cutting frozen sections of large (greater than 60 cc) blocks of monkey brain using the conventional procedures of infiltration with 30% sucrose as a cryoprotectant before freezing with pulverized dry ice often produces unacceptable levels of freezing artifact (FA) caused by displacement of tissue by ice crystals. Experiments investigating FA utilized perfusion-fixed brains from 46 monkeys and spanned combinations of cryoprotectants (glycerol, sucrose), freezing methods (dry ice or -75 degrees C isopentane), and fixatives (10% formalin, Karnovsky's or Timm's). The effects were evaluated by rating of FA severity in frozen sections of whole monkey brains. Minor FA appears as enlarged capillaries, more serious FA as large vacuoles, and both first appear midway between the periphery and center of the block. Stronger fixatives increased the severity of freezing artifact. The best method for eliminating FA was graded infiltration with up to 20% glycerol and 2% DMSO (in buffer or fixative), followed by rapid freezing in -75 degrees C isopentane. Although using a glycerol-DMSO infiltration before conventional freezing with pulverized dry ice or using conventional sucrose infiltration before freezing in isopentane gave better results than sucrose infiltration and dry-ice freezing, only the combination of glycerol-DMSO infiltration and freezing in isopentane produced consistently excellent results and virtually eliminated freezing artifact. To determine the effect of freezing with dry ice or isopentane on the rate of cooling in large blocks of CNS tissue, thermocouples were embedded in an 80-cc block of albumin-gelatin and frozen with the two methods. The rate of cooling (-3.5 degrees C/min) was twice as fast using isopentane.

HIV-1 actively replicates in dendritic cell (DC)-T cell cocultures, but it has been difficult to demonstrate substantial infection of purified mature DCs. We now find that HIV-1 begins reverse transcription much more efficiently in DCs than T cells, even though T cells have higher levels of CD4 and gp120 binding. DCs isolated from skin or from blood precursors behave similarly. Several M-tropic strains and the T-tropic strain IIIB enter DCs efficiently, as assessed by the progressive formation of the early products of reverse transcription after a 90-min virus pulse at 37 degrees C. However, few late gag-containing sequences are detected, so that active viral replication does not occur. The formation of these early transcripts seems to follow entry of HIV-1, rather than binding of virions that contain viral DNA. Early transcripts are scarce if DCs are exposed to virus on ice for 4 h, or for 90 min at 37 degrees C, conditions which allow virus binding. Also the early transcripts once formed are insensitive to trypsin. The entry of a M-tropic isolates is blocked by the chemokine RANTES, and the entry of IIIB by SDF-1. RANTES interacts with CCR5 and SDF-1 with CXCR4 receptors. Entry of M-tropic but not T-tropic virus is ablated in DCs from individuals who lack a functional CCR5 receptor. DCs express more CCR5 and CXCR4 mRNA than T cells. Therefore, while HIV-1 does not replicate efficiently in mature DCs, viral entry can be active and can be blocked by chemokines that act on known receptors for M- and T-tropic virus.

OBJECTIVE

Recent studies have shown that induced hypothermia for twelve to twenty four hours improves outcome in patients who are resuscitated from out-of-hospital cardiac arrest. These studies used surface cooling, but this technique provided for relatively slow decreases in core temperature. Results from animal models suggest that further improvements in outcome may be possible if hypothermia is induced earlier after resuscitation from cardiac arrest. We hypothesized that a rapid infusion of large volume (30 ml/kg), ice-cold (4 degrees C) intravenous fluid would be a safe, rapid and inexpensive technique to induce mild hypothermia in comatose survivors of out-of-hospital cardiac arrest.

METHODS

We enrolled 22 patients who were comatose following resuscitation from out-of-hospital cardiac arrest. After initial evaluation in the Emergency Department (ED), a large volume (30 ml/kg) of ice-cold (4 degrees C) lactated Ringers solution was infused intravenously over 30 min. Data on vital signs, arterial blood gas, electrolyte and hematological was collected immediately before and after the infusion.

RESULTS

The rapid infusion of large volume, ice-cold crystalloid fluid resulted in a significant decrease in median core temperature from 35.5 to 33.8 degrees C. There were also significant improvements in mean arterial blood pressure, renal function and acid-base analysis. No patient developed pulmonary odema.

CONCLUSIONS

A rapid infusion of large volume, ice-cold crystalloid fluid is an inexpensive and effective method of inducing mild hypothermia in comatose survivors of out-of-hospital cardiac arrest, and is associated with beneficial haemodynamic, renal and acid-base effects. Further studies of this technique are warranted.

Phylogenetic analysis of the CED-3/ICE family of cysteine proteases suggests the existence of a subfamily most related to the Caenorhabditis elegans death gene ced-3 and includes Yama (CPP32, apopain), LAP3 (Mch3, CMH1), and Mch2. Here, we show that Mch2 is processed from its zymogen form to a proteolytically active dimeric species during execution of the apoptotic program and by the cytotoxic T cell death protease granzyme B. Additionally, like Yama and LAP3, Mch2 functions downstream of the death inhibitors Bcl-2, Bcl-xL, and CrmA. Importantly, Mch2, but not Yama or LAP3, is capable of cleaving lamin A to its signature apoptotic fragment, indicating that Mch2 is an apoptotic laminase.

Modern climate change is dominated by human influences, which are now large enough to exceed the bounds of natural variability. The main source of global climate change is human-induced changes in atmospheric composition. These perturbations primarily result from emissions associated with energy use, but on local and regional scales, urbanization and land use changes are also important. Although there has been progress in monitoring and understanding climate change, there remain many scientific, technical, and institutional impediments to precisely planning for, adapting to, and mitigating the effects of climate change. There is still considerable uncertainty about the rates of change that can be expected, but it is clear that these changes will be increasingly manifested in important and tangible ways, such as changes in extremes of temperature and precipitation, decreases in seasonal and perennial snow and ice extent, and sea level rise. Anthropogenic climate change is now likely to continue for many centuries. We are venturing into the unknown with climate, and its associated impacts could be quite disruptive.

Eukaryotic cells can initiate movement using the forces exerted by polymerizing actin filaments to extend lamellipodial and filopodial protrusions. In the current model, actin filaments in lamellipodia are organized in a branched, dendritic network. We applied electron tomography to vitreously frozen 'live' cells, fixed cells and cytoskeletons, embedded in vitreous ice or in deep-negative stain. In lamellipodia from four cell types, including rapidly migrating fish keratocytes, we found that actin filaments are almost exclusively unbranched. The vast majority of apparent filament junctions proved to be overlapping filaments, rather than branched end-to-side junctions. Analysis of the tomograms revealed that actin filaments terminate at the membrane interface within a zone several hundred nanometres wide at the lamellipodium front, and yielded the first direct measurements of filament densities. Actin filament pairs were also identified as lamellipodium components and bundle precursors. These data provide a new structural basis for understanding actin-driven protrusion during cell migration.

Radiosensitive cell lines derived from X-ray cross complementing group 5 (XRCC5), SCID mice and a human glioma cell line lack components of the DNA-dependent protein kinase, DNA-PK, suggesting that DNA-PK plays an important role in DNA double-strand break repair. Another enzyme implicated in DNA repair, poly(ADP-ribose) polymerase, is cleaved and inactivated during apoptosis, suggesting that some DNA repair proteins may be selectively targeted for destruction during apoptosis. Here we demonstrate that DNA-PKcs, the catalytic subunit of DNA-PK, is preferentially degraded after the exposure of different cell types to a variety of agents known to cause apoptosis. However, Ku, the DNA-binding component of the enzyme, remains intact. Degradation of DNA-PKcs was accompanied by loss of DNA-PK activity. One cell line resistant to etoposide-induced apoptosis failed to show degradation of DNA-PKcs. Protease inhibitor data implicated an ICE-like protease in the cleavage of DNA-PKcs, and it was subsequently shown that the cysteine protease CPP32, but not Mch2alpha, ICE or TX, cleaved purified DNA-PKcs into three fragments of comparable size with those observed in cells undergoing apoptosis. Cleavage sites in DNA-PKcs, determined by antibody mapping and microsequencing, were shown to be the same for CPP32 cleavage and for cleavage catalyzed by extracts from cells undergoing apoptosis. These observations suggest that DNA-PKcs is a critical target for proteolysis by an ICE-like protease during apoptosis.

SXT is an integrating conjugative element (ICE) that was initially isolated from a 1992 Vibrio cholerae O139 clinical isolate from India. This approximately 100-kb ICE encodes resistance to multiple antibiotics. SXT or closely related ICEs are now present in most clinical and some environmental V. cholerae isolates from Asia and Africa. SXT-related ICEs are not limited to V. cholerae. It is now clear that so-called IncJ elements such as R391 are closely related to SXT. More than 25 members of the SXT/R391 family of ICEs have now been identified in environmental and clinical isolates of diverse species of gamma-proteobacteria worldwide. In this review, we discuss the diversity, evolution and biology of this family of ICEs.

Here, palaeobotanical and genetic data for common beech (Fagus sylvatica) in Europe are used to evaluate the genetic consequences of long-term survival in refuge areas and postglacial spread. Four large datasets are presented, including over 400 fossil-pollen sites, 80 plant-macrofossil sites, and 450 and 600 modern beech populations for chloroplast and nuclear markers, respectively. The largely complementary palaeobotanical and genetic data indicate that: (i) beech survived the last glacial period in multiple refuge areas; (ii) the central European refugia were separated from the Mediterranean refugia; (iii) the Mediterranean refuges did not contribute to the colonization of central and northern Europe; (iv) some populations expanded considerably during the postglacial period, while others experienced only a limited expansion; (v) the mountain chains were not geographical barriers for beech but rather facilitated its diffusion; and (vi) the modern genetic diversity was shaped over multiple glacial-interglacial cycles. This scenario differs from many recent treatments of tree phylogeography in Europe that largely focus on the last ice age and the postglacial period to interpret genetic structure and argue that the southern peninsulas (Iberian, Italian and Balkan) were the main source areas for trees in central and northern Europe.

Induction of apoptosis in keratinocytes by UV light is a critical event in photocarcinogenesis. Although p53 is of importance in this process, evidence exists that other pathways play a role as well. Therefore, we studied whether the apoptosis-related surface molecule CD95 (Fas/APO-1) is involved. The human keratinocyte cell line HaCaT expresses CD95 and undergoes apoptosis after treatment with UV light or with the ligand of CD95 (CD95L). Incubation with a neutralizing CD95 antibody completely prevented CD95L-induced apoptosis but not UV-induced apoptosis, initially suggesting that the CD95 pathway may not be involved. However, the protease CPP32, a downstream molecule of the CD95 pathway, was activated in UV-exposed HaCaT cells, and UV-induced apoptosis was blocked by the ICE protease inhibitor zVAD, implying that at least similar downstream events are involved in CD95- and UV-induced apoptosis. Activation of CD95 results in recruitment of the Fas-associated protein with death domain (FADD) that activates ICE proteases. Immunoprecipitation of UV-exposed HaCaT cells revealed that UV light also induces recruitment of FADD to CD95. Since neutralizing anti-CD95 antibodies failed to prevent UV-induced apoptosis, this suggested that UV light directly activates CD95 independently of the ligand CD95L. Confocal laser scanning microscopy showed that UV light induced clustering of CD95 in the same fashion as CD95L. Prevention of UV-induced CD95 clustering by irradiating cells at 10 degrees C was associated with a significantly reduced death rate. Together, these data indicate that UV light directly stimulates CD95 and thereby activates the CD95 pathway to induce apoptosis independently of the natural ligand CD95L. These findings further support the concept that UV light can affect targets at the plasma membrane, thereby even inducing apoptosis.

BACKGROUND

Staphylococcus aureus native valve infective endocarditis (SA-NVIE) is not completely understood. The objective of this investigation was to describe the characteristics of a large, international cohort of patients with SA-NVIE.

METHODS

The International Collaboration on Endocarditis Merged Database (ICE-MD) is a combination of 7 existing electronic databases from 5 countries that contains data on 2212 cases of definite infective endocarditis (IE).

RESULTS

Of patients with native valve IE, 566 patients [corrected] had IE due to S. aureus, and 1074 patients had IE due to pathogens other than S. aureus (non-SA-NVIE). Patients with S. aureus IE were more likely to die (20% vs. 12%; P < .001), to experience an embolic event (61% [corrected] vs. 31%; P < .001), or to have a central nervous system event (21% [corrected] vs. 13%; P < .001) and were less likely to undergo surgery (26% vs. 39%; P < .001) than were patients with non-SA-NVIE. Multivariate analysis of prognostic factors of mortality identified age (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.7), periannular abscess (OR, 2.4; 95% CI, 1.0 [corrected] -5.6), heart failure (OR, 3.9; 95% CI, 2.3-6.7), and absence of surgical therapy (OR, 2.3; 95% CI, 1.3-4.2) as variables that were independently associated with mortality in patients with SA-NVIE. After adjusting for patient-, pathogen-, and treatment-specific characteristics by multivariate analysis, geographical region was also found to be associated with mortality in patients with SA-NVIE (P < .001).

CONCLUSIONS

S. aureus is an important and common cause of IE. The outcome of SA-NVIE is worse than that of non-SA-NVIE. Several clinical parameters are independently associated with mortality for patients with SA-NVIE. The clinical characteristics and outcome of SA-NVIE vary significantly by geographic region, although the reasons for such regional variations in outcomes of SA-NVIE are unknown and are probably multifactorial. A large, prospective, multinational cohort study of patients with IE is now under way to further investigate these observations.

Experimental evidence and clinical observations indicate that brain inflammation is an important factor in epilepsy. In particular, induction of interleukin-converting enzyme (ICE)/caspase-1 and activation of interleukin (IL)-1β/IL-1 receptor type 1 axis both occur in human epilepsy, and contribute to experimentally induced acute seizures. In this study, the anticonvulsant activity of VX-765 (a selective ICE/caspase-1 inhibitor) was examined in a mouse model of chronic epilepsy with spontaneous recurrent epileptic activity refractory to some common anticonvulsant drugs. Moreover, the effects of this drug were studied in one acute model of seizures in mice, previously shown to involve activation of ICE/caspase-1. Quantitative analysis of electroencephalogram activity was done in mice exposed to acute seizures or those developing chronic epileptic activity after status epilepticus to assess the anticonvulsant effects of systemic administration of VX-765. Histological and immunohistochemical analysis of brain tissue was carried out at the end of pharmacological experiments in epileptic mice to evaluate neuropathology, glia activation and IL-1β expression, and the effect of treatment. Repeated systemic administration of VX-765 significantly reduced chronic epileptic activity in mice in a dose-dependent fashion (12.5-200 mg/kg). This effect was observed at doses ≥ 50 mg/kg, and was reversible with discontinuation of the drug. Maximal drug effect was associated with inhibition of IL-1β synthesis in activated astrocytes. The same dose regimen of VX-765 also reduced acute seizures in mice and delayed their onset time. These results support a new target system for anticonvulsant pharmacological intervention to control epileptic activity that does not respond to some common anticonvulsant drugs.

X-ray absorption spectroscopy and x-ray Raman scattering were used to probe the molecular arrangement in the first coordination shell of liquid water. The local structure is characterized by comparison with bulk and surface of ordinary hexagonal ice Ih and with calculated spectra. Most molecules in liquid water are in two hydrogen-bonded configurations with one strong donor and one strong acceptor hydrogen bond in contrast to the four hydrogen-bonded tetrahedral structure in ice. Upon heating from 25 degrees C to 90 degrees C, 5 to 10% of the molecules change from tetrahedral environments to two hydrogen-bonded configurations. Our findings are consistent with neutron and x-ray diffraction data, and combining the results sets a strong limit for possible local structure distributions in liquid water. Serious discrepancies with structures based on current molecular dynamics simulations are observed.