Signature Patterns of MHC Diversity in Three Gombe Communities of Wild Chimpanzees Reflect Fitness in Reproduction and Immune Defense against SIVcpz

Major histocompatibility complex (MHC) class I molecules determine immune responses to viral infections. These polymorphic cell-surface glycoproteins bind peptide antigens, forming ligands for cytotoxic T and natural killer cell receptors. Under pressure from rapidly evolving viruses, hominoid MHC class I molecules also evolve rapidly, becoming diverse and species-specific. Little is known of the impact of infectious disease epidemics on MHC class I variant distributions in human populations, a context in which the chimpanzee is the superior animal model. Population dynamics of the chimpanzees inhabiting Gombe National Park, Tanzania have been studied for over 50 years. This population is infected with SIVcpz, the precursor of human HIV-1. Because HLA-B is the most polymorphic human MHC class I molecule and correlates strongly with HIV-1 progression, we determined sequences for its ortholog, Patr-B, in 125 Gombe chimpanzees. Eleven Patr-B variants were defined, as were their frequencies in Gombe’s three communities, changes in frequency with time, and effect of SIVcpz infection. The growing populations of the northern and central communities, where SIVcpz is less prevalent, have stable distributions comprising a majority of low-frequency Patr-B variants and a few high-frequency variants. Driving the latter to high frequency has been the fecundity of immigrants to the northern community, whereas in the central community, it has been the fecundity of socially dominant individuals. In the declining population of the southern community, where greater SIVcpz prevalence is associated with mortality and emigration, Patr-B variant distributions have been changing. Enriched in this community are Patr-B variants that engage with natural killer cell receptors. Elevated among SIVcpz-infected chimpanzees, the Patr-B*06:03 variant has striking structural and functional similarities to HLA-B*57, the human allotype most strongly associated with delayed HIV-1 progression. Like HLA-B*57, Patr-B*06:03 correlates with reduced viral load, as assessed by detection of SIVcpz RNA in feces.     

Sick Leave within 5 Years of Whiplash Trauma Predicts Recovery: A Prospective Cohort and Register-Based Study

Background

10–22% of individuals sustaining whiplash trauma develop persistent symptoms resulting in reduced working ability and decreased quality of life, but it is poorly understood why some people do not recover. Various collision and post-collision risk factors have been studied, but little is known about pre-collision risk factors. In particular, the impact of sickness and socioeconomic factors before the collision on recovery is sparsely explored. The aim of this study was to examine if welfare payments received within five years pre-collision predict neck pain and negative change in provisional situation one year post-collision.

Methods and Findings

719 individuals with acute whiplash trauma consecutively recruited from emergency departments or primary care after car accidents in Denmark completed questionnaires on socio-demographic and health factors immediately after the collision. After 12 months, a visual analogue scale on neck pain intensity was completed. 3595 matched controls in the general population were sampled, and national public register data on social benefits and any other welfare payments were obtained for participants with acute whiplash trauma and controls from five years pre-collision to 15 months after. Participants with acute whiplash trauma who had received sickness benefit for more than 12 weeks pre-collision had increased odds for negative change in future provisional situation (Odds Ratio (OR) (95% Confidence Interval (CI) = 3.8 (2.1;7.1)) and future neck pain (OR (95%CI) = 3.3 (1.8;6.3)), controlling for other known risk factors. Participants with acute whiplash trauma had weaker attachment to labour market (more weeks of sick leave (χ²(2) = 36.7, p < 0.001) and unemployment (χ²(2) = 12.5, p = 0.002)) pre-collision compared with controls. Experiencing a whiplash trauma raised the odds for future negative change in provisional situation (OR (95%CI) = 3.1 (2.3;4.4)) compared with controls.

Conclusions

Sick leave before the collision strongly predicted prolonged recovery following whiplash trauma. Participants with acute whiplash trauma had weaker attachment to labour market pre-collision compared with the general population. Neck pain at inclusion predicted future neck pain. Acute whiplash trauma may trigger pre-existing vulnerabilities increasing risk of developing whiplash-associated disorders.     

Disrupted seasonal biology impacts health,food security and ecosystems

The rhythm of life on earth is shaped by seasonal changes in the environment. Plants and animals show profound annual cycles in physiology, health, morphology, behaviour and demography in response to environmental cues. Seasonal biology impacts ecosystems and agriculture, with consequences for humans and biodiversity. Human populations show robust annual rhythms in health and well-being, and the birth month can have lasting effects that persist throughout life. This review emphasizes the need for a better understanding of seasonal biology against the backdrop of its rapidly progressing disruption through climate change, human lifestyles and other anthropogenic impact. Climate change is modifying annual rhythms to which numerous organisms have adapted, with potential consequences for industries relating to health, ecosystems and food security. Disconcertingly, human lifestyles under artificial conditions of eternal summer provide the most extreme example for disconnect from natural seasons, making humans vulnerable to increased morbidity and mortality. In this review, we introduce scenarios of seasonal disruption, highlight key aspects of seasonal biology and summarize from biomedical, anthropological, veterinary, agricultural and environmental perspectives the recent evidence for seasonal desynchronization between environmental factors and internal rhythms. Because annual rhythms are pervasive across biological systems, they provide a common framework for trans-disciplinary research.     

Membrane cofactor protein (MCP or CD46) is a cellular pilus receptor for pathogenic Neisseria

The Bacillus subtilis RecR protein is required for DNA repair and recombination in vivo . In its N-terminal portion, RecR possesses potential zinc-ligand structures associated with the multicysteine (C₄) superfamily. The number and arrangement of the cysteine residues is suggestive of RecR being a zinc-finger protein. One of the four cysteines (Cys-60) has been replaced by a Ser (C60S) or an Ala (C60A) residue to generate the recR60 and recR601 genes, respectively. B. subtilis recR60 , recR601 or Δ recR1 (a null-mutant allele) cells are 10-, 134- and 144-fold more sensitive to 10 mM methanesulphonate and 95-, 900- and 1100-fold more sensitive to the lethal effect of 100 μM 4-nitroquinoline-1-oxide (4NQO) than the wild-type strain, respectively. The RecR zinc-ligand C₄ motif does not seem to be accessible, because the protein is highly resistant to oxidation and moderately resistant to reduction. We have determined by different biochemical methods that RecR is a zinc metalloprotein whose cysteine residues have a structural and/or functional role.     

Concerted evolution of polymorphic MHC class II β loci: a comment to reviewer's reply

Address correspondence and offprint requests to: L. Andersson     

Exploring potential biodiversity indicators in boreal forests

The present study evaluates indicators in Swedish spruce forests. We ask whether different species groups co-vary in their occurrence and to what extent species richness and composition is predictable from habitat structures. We studied 10 boreal spruce forest stands constituting a gradient in degree of selective logging. Occurrences of vascular plants, bryophytes, epiphytic lichens and wood-inhabiting fungi as well as habitat structures was inventoried. In addition, in five of the stands, beetles were sampled with windows traps. Total species richness was correlated with several habitat factors, mainly particular substrates and degree of forestry impact. However, the richness of a set of species regularly used as indicators did not correlate with habitat factors. Correlation in species richness among different organism groups were few and scale dependent. Only lichens and vascular plants formed nested subset patterns (i.e. species composition at poorer sites is subsets of the species present at richer sites) among the study sites. The study shows that in this forest type one cannot a priori assume that richness in one group of species correlated with richness in other, and measures of single habitat features may be relevant only to particular groups of species. Instead, monitoring and inventories should be based on a set of factors reflecting important aspects for different groups of organisms and if indicator species are to be used these should be chosen from several species groups.     

Structural mapping of an aggregation nucleation site in a molten globule intermediate.

Protein aggregation plays an important role in biotechnology and also causes numerous diseases. Human carbonic anhydrase II is a suitable model protein for studying the mechanism of aggregation. We found that a molten globule state of the enzyme formed aggregates. The intermolecular interactions involved in aggregate formation were localized in a direct way by measuring excimer formation between each of 20 site-specific pyrene-labeled cysteine mutants. The contact area of the aggregated protein was very specific, and all sites included in the intermolecular interactions were located in the large beta-sheet of the protein, within a limited region between the central beta-strands 4 and 7. This substructure is very hydrophobic, which underlines the importance of hydrophobic interactions between specific beta-sheet containing regions in aggregate formation.     

Does risk of predation by mammalian predators affect the spacing behaviour of rodents? Two large-scale experiments

Predator-prey interactions between small mammals and their avian and mammalian predators have attracted much attention. However, large-scale field experiments examining small-mammal antipredatory responses under the risk of predation by mammals are rare. As recently pointed out, the scale of experiments may cause misleading results in studies of decision-making under predation risk. We studied the effect of small mustelid predators on the spacing behaviour of the gray-tailed vole (Microtus canicaudus) and the bank vole (Clethrionomys glareolus) in two separate field enclosure experiments. The experiments were conducted during the breeding season in North America and northern Europe, where small mustelids have been suggested to be important mammalian predators of voles. As in most of the earlier laboratory studies, predation risk was simulated using fresh mustelid faeces and urine. This made it possible to compare the results from experiments at different spatial scales. We did not find any effect of increased predation risk on spacing behaviour (mean and/or maximum distance moved and home range size) or trappability in either vole species. Simulated predation risk did not affect the breeding of females in gray-tailed voles, as has previously been shown in bank voles. The results disagree with most of the studies conducted in laboratory conditions with small mammals. We discuss whether this discrepancy could be caused by differences in the scale of the experiments. Received: 12 April 1999 / Accepted: 7 October 1999