Pathophysiological significance of peroxidative stress, neuronal damage, and membrane permeability in acute mountain sickness.

Free radical-mediated changes in vascular permeability and subsequent inflammatory response may be a contributory pathogenetic cofactor responsible for the development of neurological sequelae associated with acute mountain sickness (AMS). To investigate this, 49 subjects were examined at sea level and serially after rapid ascent to 4,559 m. Although the venous concentration of total creatine phosphokinase activity was measured in all subjects, a complementary examination of lipid peroxidation (F(2)-isoprostanes), inflammatory (TNF-alpha, IL-1beta, IL-2, IL-6, IL-8, C-reactive protein), and cerebrovascular tissue damage (neuron-specific enolase) biomarkers was confined to a subcohort of 24 subjects. A selective increase (P < 0.05) in total creatine phosphokinase was observed in subjects diagnosed with AMS at high altitude (n = 25) compared with apparently healthy controls (n = 24). However, despite a marked increase in IL-6 and C-reactive protein attributable primarily to subjects developing high-altitude pulmonary edema, subcohort analyses demonstrated no selective differences in F(2)-isoprostanes, neuron-specific enolase, or remaining proinflammatory cytokines due to AMS (n = 14). The present findings are the first to demonstrate that free radical-mediated neuronal damage of sufficient degree to be detected in the peripheral circulation does not occur and is, therefore, unlikely to be an important, initiating event that is critical for the development of AMS. The pathophysiological significance of increased sarcolemmal membrane permeability and inflammatory response, either as a cause or epiphenomenon of AMS and/or high-altitude pulmonary edema, remains to be elucidated.     

Fire, soil fertility and delayed seed release: a community analysis of the degree of serotiny

Delayed seed release (serotiny) is a convergent plant trait in fire-prone regions of the world but explaining the degree of serotiny has remained elusive because of the paucity of community data. Selective forces involving seed predators, fire and soil nutrients have been suggested as factors influencing serotiny. We tested whether protection of seeds and/or synchronized dispersal were associated with different levels of serotiny and if resprouting ability influences selection for strong serotiny. We compared the numbers and abundance of 146 woody species with delayed dispersal among five community types varying in combinations of fire severity, fire frequency, soil fertility and seed predators. The strength of the relationship between levels of serotiny and environmental factors was tested among community types ranging from rainforests to heathlands. Highest levels of serotiny were recorded in low nutrient shrublands with intermediate fire return intervals that burn at high severity, while the lowest were recorded in high nutrient, low flammability forests. Both protection of seeds and synchronized seed release were related to fire effects in nutrient-limited environments. Strong serotiny is prominent in species killed by fire whereas weak serotiny is more common in resprouting species. Recruitment failure in the inter-fire interval appears to drive selection for strong maternal care of seeds and synchronized seed dispersal in fire-prone environments. Weak serotiny is proposed as a bet-hedging strategy that relies on resprouting after fire for population persistence and higher probability of inter-fire recruitment. The spectrum of serotiny (weak to strong) in these communities is proposed to be driven by the interactive effect of both fire and soil nutrients on the selection for delayed seed dispersal.     

Investigating the relationship between olfactory acuity,disgust, and mating strategies

Although humans' sense of smell is relatively diminished compared to other species, olfaction is still a central sensory modality through which people evaluate both potential threats and prospective romantic partners. Despite olfaction's role in interpersonal relationships and disease avoidant responses, however, it remains unknown whether variation in olfactory acuity is associated with disease- and mating-relevant psychological constructs and behaviors. In the current exploratory study, we examined the relationships between olfactory acuity, disgust sensitivity, and mating strategies in a sample of undergraduate students (N = 162) at a university in the Southern United States using an extended assessment of olfactory acuity (measuring olfactory threshold, discrimination, and identification). Results revealed that people with greater discrimination acuity were higher in dispositional sexual disgust, but not pathogen or moral disgust. People with greater discrimination acuity were also less inclined towards short-term mating. Further, sexual disgust mediated the relationship between discrimination acuity and short-term mating orientation. These results provide further evidence for the importance of olfaction and olfaction-related disgust in close relationships.     

A Virus-Like Particle That Elicits Cross-Reactive Antibodies to the Conserved Stem of Influenza Virus Hemagglutinin

The discovery of broadly neutralizing antibodies that recognize highly conserved epitopes in the membrane-proximal region of influenza virus hemagglutinin (HA) has revitalized efforts to develop a universal influenza virus vaccine. This effort will likely require novel immunogens that contain these epitopes but lack the variable and immunodominant epitopes located in the globular head of HA. As a first step toward developing such an immunogen, we investigated whether the 20-residue A-helix of the HA2 chain that forms the major component of the epitope of broadly neutralizing antibodies CR6261, F10, and others is sufficient by itself to elicit antibodies with similarly broad antiviral activity. Here, we report the multivalent display of the A-helix on icosahedral virus-like particles (VLPs) derived from the capsid of Flock House virus. Mice immunized with VLPs displaying 180 copies/particle of the A-helix produced antibodies that recognized trimeric HA and the elicited antibodies had binding characteristics similar to those of CR6261 and F10: they recognized multiple HA subtypes from group 1 but not from group 2. However, the anti-A-helix antibodies did not neutralize influenza virus. These results indicate that further engineering of the transplanted peptide is required and that display of additional regions of the epitope may be necessary to achieve protection.     

Delineating the glioblastoma stemness by genes involved in cytoskeletal rearrangements and metabolic alterations

Literature data on glioblastoma ongoingly underline the link between metabolism and cancer stemness, the latter is one responsible for potentiating the resistance to treatment, inter alia due to increased invasiveness. In recent years, glioblastoma stemness research has bashfully introduced a key aspect of cytoskeletal rearrangements, whereas the impact of the cytoskeleton on invasiveness is well known. Although non-stem glioblastoma cells are less invasive than glioblastoma stem cells (GSCs), these cells also acquire stemness with greater ease if characterized as invasive cells and not tumor core cells. This suggests that glioblastoma stemness should be further investigated for any phenomena related to the cytoskeleton and metabolism, as they may provide new invasion-related insights. Previously, we proved that interplay between metabolism and cytoskeleton existed in glioblastoma. Despite searching for cytoskeleton-related processes in which the investigated genes might have been involved, not only did we stumble across the relation to metabolism but also reported genes that were found to be implicated in stemness. Thus, dedicated research on these genes in GSCs seems justifiable and might reveal novel directions and/or biomarkers that could be utilized in the future. Herein, we review the previously identified cytoskeleton/metabolism-related genes through the prism of glioblastoma stemness.     

Processing of envelope polypeptides of Herpes simplex virus type 1: Demonstration of variation in different cell lines by high-performance liquid chromatography and radioimmunoprecipitation

[³⁵S]Methionine-labelled envelope polypeptides of Herpes simplex virus type 1, strain F, propagated in mammalian cell culture of various origins, were separated by ion-exchange high-performance liquid chromatography on a TSK DEAE-3SW column. Analysis of the fractions by radioimmunoprecipitation followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis of the immunoprecipitates showed similarities as well as distinct differences in the number, migration patterns and molecular mass of the synthesized polypeptides, depending on the host cell. The results show that this method can be used to demonstrate species-specific or organ-specific differences in the processing of virus-specified polypeptides synthesized in host cells.     

Artificial refuges for wildlife conservation: what is the state of the science?

Artificial refuges are human-made structures that aim to create safe places for animals to breed, hibernate, or take shelter in lieu of natural refuges. Artificial refuges are used across the globe to mitigate the impacts of a variety of threats on wildlife, such as habitat loss and degradation. However, there is little understanding of the science underpinning artificial refuges, and what comprises best practice for artificial refuge design and implementation for wildlife conservation. We address this gap by undertaking a systematic review of the current state of artificial refuge research for the conservation of wildlife. We identified 224 studies of artificial refuges being implemented in the field to conserve wildlife species. The current literature on artificial refuges is dominated by studies of arboreal species, primarily birds and bats. Threatening processes addressed by artificial refuges were biological resource use (26%), invasive or problematic species (20%), and agriculture (15%), yet few studies examined artificial refuges specifically for threatened (Vulnerable, Endangered, or Critically Endangered) species (7%). Studies often reported the characteristics of artificial refuges (i.e. refuge size, construction materials; 87%) and surrounding vegetation (35%), but fewer studies measured the thermal properties of artificial refuges (18%), predator activity (17%), or food availability (3%). Almost all studies measured occupancy of the artificial refuges by target species (98%), and over half measured breeding activity (54%), whereas fewer included more detailed measures of fitness, such as breeding productivity (34%) or animal body condition (4%). Evaluating the benefits and impacts of artificial refuges requires sound experimental design, but only 39% of studies compared artificial refuges to experimental controls, and only 10% of studies used a before-after-control-impact (BACI) design. As a consequence, few studies of artificial refuges can determine their overall effect on individuals or populations. We outline a series of key steps in the design, implementation, and monitoring of artificial refuges that are required to avoid perverse outcomes and maximise the chances of achieving conservation objectives. This review highlights a clear need for increased rigour in studies of artificial refuges if they are to play an important role in wildlife conservation.     

Superoxide dismutase 1: Identification of a novel mutation in a case of familial amyotrophic lateral sclerosis

Mutation analysis of the superoxide dismutase gene SOD1 in a familial case of amyotrophic lateral sclerosis revealed a T→C transition at codon 151 of exon 5. This mutation results in the substitution of an isoleucine for a threonine. It appears to affect formation of dimers of the protein and is the most C-terminal amino acid change in SOD1 described to date. Received: 5 February 1996 / Revised: 9 February 1996     

State-dependent male mating tactics in the grey seal: the importance of body size

The purpose of this study was to examine the importance of bodysize and body composition as determinants of conditional matingtactics exhibited in male grey seals. We combined behavioralobservations with measures of energy expenditure and successon 42 known-age individuals during the breeding seasons of 1997–2001at Sable Island, Canada. Males with a large body mass arrivedat the breeding grounds with more body fat and body energy andcatabolized less body protein than smaller males. Males consumed1.9 ± 0.2 MJ day^–1, and those with a smaller percentageof body fat had higher rates of food energy intake. The amountof body energy on arrival was positively correlated with theduration of the breeding period. Males that exhibited the primarymating tactic of consortship were heavier, had absolutely morebody fat and body energy, and sustained breeding longer thanthose males that did not exhibit the primary tactic. Amongstall males, body mass showed a quadratic relationship with thenumber of female consorts mated and the estimated number ofpups sired. Thus, intermediate-sized males mated with the mostconsorts and achieved the highest success. Intermediate bodysize may be optimal during breeding due to greater agility inmale combat. Body size was an important determinant of matingtactics used by male grey seals. A large body size providedan energetic advantage of greater endurance while an intermediatebody size may provide greater competitive ability in acquiringconsortships.