bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistent predator–prey dynamics revealed by mass extinction
Authors: Sallan Lauren Cole , Kammer Thomas W. , Ausich William I. , Cook Lewis A.
Published: May 2011

Predator–prey interactions are thought by many researchers to define both modern ecosystems and past macroevolutionary events. In modern ecosystems, experimental removal or addition of taxa is often used to determine trophic relationships and predator identity. Both characteristics are notoriously difficult to infer in the fossil record, where evidence of predation is usually limited to damage from failed attacks, individual stomach contents, one-sided escalation, or modern analogs. As a result, the role of predation in macroevolution is often dismissed in favor of competition and abiotic factors. Here we show that the end-Devonian Hangenberg event (359 Mya) was a natural experiment in which vertebrate predators were both removed and added to an otherwise stable prey fauna, revealing specific and persistent trophic interactions. Despite apparently favorable environmental conditions, crinoids diversified only after removal of their vertebrate consumers, exhibiting predatory release on a geological time scale. In contrast, later Mississippian (359–318 Mya) camerate crinoids declined precipitously in the face of increasing predation pressure from new durophagous fishes. Camerate failure is linked to the retention of obsolete defenses or “legacy adaptations” that prevented coevolutionary escalation. Our results suggest that major crinoid evolutionary phenomena, including rapid diversification, faunal turnover, and species selection, might be linked to vertebrate predation. Thus, interactions observed in small ecosystems, such as Lotka-Volterra cycles and trophic cascades, could operate at geologic time scales and higher taxonomic ranks. Both trophic knock-on effects and retention of obsolete traits might be common in the aftermath of predator extinction.
SecB-like chaperone controls a toxin–antitoxin stress-responsive system in
Mycobacterium tuberculosis
Authors: Bordes Patricia , Cirinesi Anne-Marie , Ummels Roy , Sala Ambre , Sakr Samer , Bitter Wilbert , Genevaux Pierre
Published: May 2011

A major step in the biogenesis of newly synthesized precursor proteins in bacteria is their targeting to the Sec translocon at the inner membrane. In Gram-negative bacteria, the chaperone SecB binds nonnative forms of precursors and specifically transfers them to the SecA motor component of the translocase, thus facilitating their export. The major human pathogen
Mycobacterium tuberculosis
is an unusual Gram-positive bacterium with a well-defined outer membrane and outer membrane proteins. Assistance to precursor proteins by chaperones in this bacterium remains largely unexplored. Here we show that the product of the previously uncharacterized
Rv1957
gene of
M. tuberculosis
can substitute for SecB functions in
Escherichia coli
and prevent preprotein aggregation in vitro. Interestingly, in
M. tuberculosis
,
Rv1957
is clustered with a functional stress-responsive
higB-higA
toxin–antitoxin (TA) locus of unknown function. Further in vivo experiments in
E. coli
and in
Mycobacterium marinum
strains that do not possess the TA-chaperone locus show that the severe toxicity of the toxin was entirely inhibited when the antitoxin and the chaperone were jointly expressed. We found that Rv1957 acts directly on the antitoxin by preventing its aggregation and protecting it from degradation. Taken together, our results show that the SecB-like chaperone Rv1957 specifically controls a stress-responsive TA system relevant for
M. tuberculosis
adaptive response.
Bromodomain protein Brd3 associates with acetylated GATA1 to promote its chromatin occupancy at erythroid target genes
Authors: Lamonica Janine M. , Deng Wulan , Kadauke Stephan , Campbell Amy E. , Gamsjaeger Roland , Wang Hongxin , Cheng Yong , Billin Andrew N. , Hardison Ross C. , Mackay Joel P. , Blobel Gerd A.
Published: May 2011

Acetylation of histones triggers association with bromodomain-containing proteins that regulate diverse chromatin-related processes. Although acetylation of transcription factors has been appreciated for some time, the mechanistic consequences are less well understood. The hematopoietic transcription factor GATA1 is acetylated at conserved lysines that are required for its stable association with chromatin. We show that the BET family protein Brd3 binds via its first bromodomain (BD1) to GATA1 in an acetylation-dependent manner in vitro and in vivo. Mutation of a single residue in BD1 that is involved in acetyl-lysine binding abrogated recruitment of Brd3 by GATA1, demonstrating that acetylation of GATA1 is essential for Brd3 association with chromatin. Notably, Brd3 is recruited by GATA1 to both active and repressed target genes in a fashion seemingly independent of histone acetylation. Anti-Brd3 ChIP followed by massively parallel sequencing in GATA1-deficient erythroid precursor cells and those that are GATA1 replete revealed that GATA1 is a major determinant of Brd3 recruitment to genomic targets within chromatin. A pharmacologic compound that occupies the acetyl-lysine binding pockets of Brd3 bromodomains disrupts the Brd3-GATA1 interaction, diminishes the chromatin occupancy of both proteins, and inhibits erythroid maturation. Together these findings provide a mechanism for GATA1 acetylation and suggest that Brd3 “reads” acetyl marks on nuclear factors to promote their stable association with chromatin.
Evolution of personality differences in leadership
Authors: Johnstone Rufus A. , Manica Andrea
Published: May 2011

When members of a group differ in their preferred course of action, coordination poses a challenge. Leadership offers one way to resolve this difficulty, but the evolution of leaders and followers is itself poorly understood. Existing discussions have frequently attributed leadership to differences in information or need among individuals. Here, however, we show that in an
n
-player, repeated coordination game, selection leads to evolutionary branching and diversification in intrinsic leadership among the members of a population even in the absence of any variation in state. When individuals interact in pairs, repeated branching is possible; when individuals interact in larger groups, the typical outcome is a single branching event leading to a dimorphism featuring extreme intrinsic leaders and followers. These personality types emerge and are maintained by frequency-dependent selection, because leaders gain by imposing their preferences on followers, but fail to coordinate effectively when interacting with other leaders. The fraction of intrinsic leaders in the population increases with the degree of conflict among group members, with both types common only at intermediate levels of conflict; when conflict is weak, most individuals are intrinsic followers, and groups achieve high levels of coordination by randomly converging on one individual's preferred option, whereas when conflict is strong, most individuals are intrinsic leaders, and coordination breaks down because members of a group are rarely willing to follow another.
RNA-guided complex from a bacterial immune system enhances target recognition through seed sequence interactions
Authors: Wiedenheft Blake , van Duijn Esther , Bultema Jelle B. , Waghmare Sakharam P. , Zhou Kaihong , Barendregt Arjan , Westphal Wiebke , Heck Albert J. R. , Boekema Egbert J. , Dickman Mark J. , Doudna Jennifer A.
Published: May 2011

Prokaryotes have evolved multiple versions of an RNA-guided adaptive immune system that targets foreign nucleic acids. In each case, transcripts derived from clustered regularly interspaced short palindromic repeats (CRISPRs) are thought to selectively target invading phage and plasmids in a sequence-specific process involving a variable cassette of CRISPR-associated (
cas
) genes. The CRISPR locus in
Pseudomonas aeruginosa
(PA14) includes four
cas
genes that are unique to and conserved in microorganisms harboring the Csy-type (CRISPR system yersinia) immune system. Here we show that the Csy proteins (Csy1–4) assemble into a 350 kDa ribonucleoprotein complex that facilitates target recognition by enhancing sequence-specific hybridization between the CRISPR RNA and complementary target sequences. Target recognition is enthalpically driven and localized to a “seed sequence” at the 5′ end of the CRISPR RNA spacer. Structural analysis of the complex by small-angle X-ray scattering and single particle electron microscopy reveals a crescent-shaped particle that bears striking resemblance to the architecture of a large CRISPR-associated complex from
Escherichia coli
, termed Cascade. Although similarity between these two complexes is not evident at the sequence level, their unequal subunit stoichiometry and quaternary architecture reveal conserved structural features that may be common among diverse CRISPR-mediated defense systems.
Diet of
Paranthropus boisei
in the early Pleistocene of East Africa
Authors: Cerling Thure E. , Mbua Emma , Kirera Francis M. , Manthi Fredrick Kyalo , Grine Frederick E. , Leakey Meave G. , Sponheimer Matt , Uno Kevin T.
Published: May 2011

The East African hominin
Paranthropus boisei
was characterized by a suite of craniodental features that have been widely interpreted as adaptations to a diet that consisted of hard objects that required powerful peak masticatory loads. These morphological adaptations represent the culmination of an evolutionary trend that began in earlier taxa such as
Australopithecus afarensis
, and presumably facilitated utilization of open habitats in the Plio-Pleistocene. Here, we use stable isotopes to show that
P. boisei
had a diet that was dominated by C
4
biomass such as grasses or sedges. Its diet included more C
4
biomass than any other hominin studied to date, including its congener
Paranthropus robustus
from South Africa. These results, coupled with recent evidence from dental microwear, may indicate that the remarkable craniodental morphology of this taxon represents an adaptation for processing large quantities of low-quality vegetation rather than hard objects.
Thrombospondin 1 inhibits inflammatory lymphangiogenesis by CD36 ligation on monocytes
Authors: Cursiefen Claus , Maruyama Kazuichi , Bock Felix , Saban Daniel , Sadrai Zahra , Lawler Jack , Dana Reza , Masli Sharmila
Published: May 2011

Lymphangiogenesis plays an important role in tumor metastasis and transplant outcome. Here, we show that thrombospondin-1 (TSP-1), a multifunctional extracellular matrix protein and naturally occurring inhibitor of angiogenesis inhibits lymphangiogenesis in mice. Compared with wild-type mice, 6-mo-old TSP-1–deficient mice develop increased spontaneous corneal lymphangiogenesis. Similarly, in a model of inflammation-induced corneal neovascularization, young TSP-1–deficient mice develop exacerbated lymphangiogenesis, which can be reversed by topical application of recombinant human TSP-1. Such increased corneal lymphangiogenesis is also detected in mice lacking CD36, a receptor for TSP-1. In these mice, repopulation of corneal macrophages with predominantly WT mice via bone marrow reconstitution ameliorates their prolymphangiogenic phenotype. In vitro, exposure of WT macrophages to TSP-1 suppresses expression of lymphangiogenic factors vascular endothelial growth factor (VEGF)-C and VEGF-D, but not of a primarily hemangiogenic factor VEGF-A. Inhibition of VEGF-C is not detected in the absence or blockade of CD36. These findings suggest that TSP-1, by ligating CD36 on monocytic cells, acts as an endogenous inhibitor of lymphangiogenesis.
Pretransplant CSF-1 therapy expands recipient macrophages and ameliorates GVHD after allogeneic hematopoietic cell transplantation
Authors: Hashimoto Daigo , Chow Andrew , Greter Melanie , Saenger Yvonne , Kwan Wing-Hong , Leboeuf Marylene , Ginhoux Florent , Ochando Jordi C. , Kunisaki Yuya , van Rooijen Nico , Liu Chen , Teshima Takanori , Heeger Peter S. , Stanley E. Richard , Frenette Paul S. , Merad Miriam
Published: May 2011

Acute graft-versus-host disease (GVHD) results from the attack of host tissues by donor allogeneic T cells and is the most serious limitation of allogeneic hematopoietic cell transplantation (allo-HCT). Host antigen-presenting cells are thought to control the priming of alloreactive T cells and the induction of acute GVHD after allo-HCT. However, whereas the role of host DC in GVHD has been established, the contribution of host macrophages to GVHD has not been clearly addressed. We show that, in contrast to DC, reducing of the host macrophage pool in recipient mice increased donor T cell expansion and aggravated GVHD mortality after allo-HCT. We also show that host macrophages that persist after allo-HCT engulf donor allogeneic T cells and inhibit their proliferation. Conversely, administration of the cytokine CSF-1 before transplant expanded the host macrophage pool, reduced donor T cell expansion, and improved GVHD morbidity and mortality after allo-HCT. This study establishes the unexpected key role of host macrophages in inhibiting GVHD and identifies CSF-1 as a potential prophylactic therapy to limit acute GVHD after allo-HCT in the clinic.
Viral persistence redirects CD4 T cell differentiation toward T follicular helper cells
Authors: Fahey Laura M. , Wilson Elizabeth B. , Elsaesser Heidi , Fistonich Chris D. , McGavern Dorian B. , Brooks David G.
Published: May 2011

CD4 T cell responses are crucial to prevent and control viral infection; however, virus-specific CD4 T cell activity is considered to be rapidly lost during many persistent viral infections. This is largely caused by the fact that during viral persistence CD4 T cells do not produce the classical Th1 cytokines associated with control of acute viral infections. Considering that CD4 T cell help is critical for both CD8 T cell and B cell functions, it is unclear how CD4 T cells can lose responsiveness but continue to sustain long-term control of persistent viral replication. We now demonstrate that CD4 T cell function is not extinguished as a result of viral persistence. Instead, viral persistence and prolonged T cell receptor stimulation progressively redirects CD4 T cell development away from the Th1 response induced during an acute infection toward T follicular helper cells. Importantly, this sustained CD4 T cell functionality is critical to maintain immunity and ultimately aid in the control of persistent viral infection.
Langerhans cells are negative regulators of the anti-Leishmania response
Authors: Kautz-Neu Kordula , Noordegraaf Madelon , Dinges Stephanie , Bennett Clare L. , John Dominik , Clausen Björn E. , von Stebut Esther
Published: May 2011

Migratory skin dendritic cells (DCs) are thought to play an important role in priming T cell immune responses against Leishmania major, but DC subtypes responsible for the induction of protective immunity against this pathogen are still controversial. In this study, we analyzed the role of Langerin+ skin-derived DCs in the Leishmania model using inducible in vivo cell ablation. After physiologically relevant low-dose infection with L. major (1,000 parasites), mice depleted of all Langerin+ DCs developed significantly smaller ear lesions with decreased parasite loads and a reduced number of CD4+ Foxp3+ regulatory T cells (T reg cells) as compared with controls. This was accompanied by increased interferon γ production in lymph nodes in the absence of Langerin+ DCs. Moreover, selective depletion of Langerhans cells (LCs) demonstrated that the absence of LCs, and not Langerin+ dermal DC, was responsible for the reduced T reg cell immigration and the enhanced Th1 response, resulting in attenuated disease. Our data reveal a unique and novel suppressive role for epidermal LCs in L. major infection by driving the expansion of T reg cells. A better understanding of the various roles of different DC subsets in cutaneous leishmaniasis will improve the development of a potent therapeutic/prophylactic vaccine.
Trypanosoma cruzi subverts the sphingomyelinase-mediated plasma membrane repair pathway for cell invasion
Authors: Fernandes Maria Cecilia , Cortez Mauro , Flannery Andrew R. , Tam Christina , Mortara Renato A. , Andrews Norma W.
Published: May 2011

Upon host cell contact, the protozoan parasite Trypanosoma cruzi triggers cytosolic Ca2+ transients that induce exocytosis of lysosomes, a process required for cell invasion. However, the exact mechanism by which lysosomal exocytosis mediates T. cruzi internalization remains unclear. We show that host cell entry by T. cruzi mimics a process of plasma membrane injury and repair that involves Ca2+-dependent exocytosis of lysosomes, delivery of acid sphingomyelinase (ASM) to the outer leaflet of the plasma membrane, and a rapid form of endocytosis that internalizes membrane lesions. Host cells incubated with T. cruzi trypomastigotes are transiently wounded, show increased levels of endocytosis, and become more susceptible to infection when injured with pore-forming toxins. Inhibition or depletion of lysosomal ASM, which blocks plasma membrane repair, markedly reduces the susceptibility of host cells to T. cruzi invasion. Notably, extracellular addition of sphingomyelinase stimulates host cell endocytosis, enhances T. cruzi invasion, and restores normal invasion levels in ASM-depleted cells. Ceramide, the product of sphingomyelin hydrolysis, is detected in newly formed parasitophorous vacuoles containing trypomastigotes but not in the few parasite-containing vacuoles formed in ASM-depleted cells. Thus, T. cruzi subverts the ASM-dependent ceramide-enriched endosomes that function in plasma membrane repair to infect host cells.
Horizontal Gene Transfer in Nematodes: A Catalyst for Plant Parasitism?
Authors: Haegeman Annelies , Jones John T. , Danchin Etienne G. J.
Published: May 2011

The origin of plant parasitism within the phylum Nematoda is intriguing. The ability to parasitize plants has originated independently at least three times during nematode evolution and, as more molecular data has emerged, it has become clear that multiple instances of horizontal gene transfer (HGT) from bacteria and fungi have played a crucial role in the nematode's adaptation to this new lifestyle. The first reported HGT cases in plant-parasitic nematodes were genes encoding plant cell wall–degrading enzymes. Other putative examples of HGT were subsequently described, including genes that may be involved in the modulation of the plant's defense system, the establishment of a nematode feeding site, and the synthesis or processing of nutrients. Although, in many cases, it is difficult to pinpoint the donor organism, candidate donors are usually soil dwelling and are either plant-pathogenic or plant-associated microorganisms, hence occupying the same ecological niche as the nematodes. The exact mechanisms of transfer are unknown, although close contacts with donor microorganisms, such as symbiotic or trophic interactions, are a possibility. The widespread occurrence of horizontally transferred genes in evolutionarily independent plant-parasitic nematode lineages suggests that HGT may be a prerequisite for successful plant parasitism in nematodes.
First Report of a Group 16SrI Phytoplasma Associated with Amaranthus hypochondriacus Cladodes in China
Authors: Long J. Y. , Chen Y. H. , Xia J. R.
Published: May 2011

Amaranthus spp. are cultivated worldwide as leafy vegetable, cereal, and ornamentals. In China, stems and leaves of Amaranthus hypochondriacus L. are used as a vegetable (2). In July 2010, sporadic amaranth plants exhibiting symptoms of cladodes and spica proliferation were observed in a vegetable garden near Foshan, Guangdong, China. Stem samples were collected from two symptomatic and two asymptomatic plants. Total DNA was extracted with a modified cetyltrimethylammonium bromide (CTAB) method (1). Nested PCR with a combination of phytoplasma-specific universal primer pairs (P1/P7 and R16F2n/R16R2) amplified 16S rDNA sequences with the expected size of 1.2 kb from all samples of symptomatic amaranth plants, but not from the asymptomatic plants (3). Nested PCR products yielded identical AluI, HhaI, HpaII, HaeIII, KpnI, MseI, RsaI, Sau3AI, and TaqI restriction fragment length polymorphism (RFLP) profiles with chinaberry witches'-broom phytoplasma (16SrI-B subgroup), but different from peanut witches'-broom phytoplasma (16SrII group), jujube witches'-broom phytoplasma (16SrV group), and paulownia witches'-broom phytoplasma (16SrI-D subgroup). Nested PCR products were purified, cloned in pMD18-T Simple Vector (TaKaRa, Dalian, China), and sequenced. The 16S rDNA sequences were identical and deposited in GenBank (Accession No. JF323034). GenBank BLASTn analysis indicated that the amaranth extracts showed as high as 99% sequence identity with the members of 16SrI group phytoplasmas, including those associated with arecanut yellow leaf disease (FJ998269) and aster yellow AY-27 (HM467127). A polygenetic tree was constructed using MEGA 4.0 based on the 16S rDNA sequences of amaranth cladode phytoplasma and other phytoplasmas belonging to 16SrI phytoplasma group. In phylogenetic analysis, the sequences clustered on a single branch with members of 16SrI-B subgroup in the tree. Therefore, the phytoplasma was classified in subgroup 16SrI-B. To our knowledge, this is the first report of a subgroup 16SrI-B phytoplasma associated with diseased A. hypochondriacus in China.

References: (1) E. Angelini et al. Vitis 40:79, 2001. (2) M. Costea et al. Econ. Bot. 57:646, 2003. (3) I. M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.
Occurrence of a Fruit Spot Disease of Pomegranates Caused by Colletotrichum gloeosporiodes in the Prefecture of Komotini, Greece
Authors: Thomidis T. , Exadaktylou E.
Published: May 2011

Pomegranate (Punica granatum L.) is an important crop in Greece. In 2010, fruits of the pomegranate cv. Wonderful, in commercial fields located in the Prefecture of Komotini in eastern Greece, were observed to have symptoms of distinct dark brown spots. The waxy acervuli observed in infected tissue were subepidermal, typically with setae and simple, short, erect conidiophores. Conidia were hyaline, one celled, ovoid to oblong, slightly curved or dumbbell shaped, and 10 to 15 μm long and 5 to 7 μm wide. The pathogen was isolated on acidified potato dextrose agar (PDA) (2.5 ml of 85% lactic acid per liter of nutrient medium) and incubated at 23°C for 7 days. The pathogen was identified as Colletotrichum gloeosporiodes (Penz) Sacc. on the basis of morphological characteristics and internal transcribed spacer (ITS) sequence (100% identity to AJ301912, C. gloeosporioides species complex) (3) by CBS Fungal Biodiversity Centre, Identification Service, Utrecht, the Netherlands, (CG-1 isolate deposited in CBS Collection; Accession No. CBS 129372). Koch's postulates were completed in the laboratory by placing a 40-μl drop of suspension (4 × 105 conidia ml–1 of water) on a wounded area of healthy fruits of cv. Wonderful. Fruits were surface sterilized by dipping in 0.1% chlorine solution and allowed to dry in a laminar flow hood. There were 15 inoculated and 15 control fruits (similarly sprayed with sterile distilled water) in a randomized design. Fruits were covered with perforated polythene bags to maintain a high humidity necessary for infection that were removed 48 h after inoculation and the fruits were maintained at room temperature (23 ± 2°C). Lesion development was recorded daily for each fruit. Koch's postulates were satisfied after reisolating the fungus from inoculated fruit that developed symptoms similar to those observed on fruits collected from fields. To our knowledge, this is the first report of the occurrence of C. gloeosporioides as a causal agent of fruit spot of pomegranates in Greece. Fruit spots caused by C. gloeosporioides have been reported in pomegranate fields of other countries around the world (1,2).

References: (1) B. K. M. Lakshmi et al. Trop. Agric. Res. 22:183, 2011. (2) D. S. Patel. Indian Phytopathol. 62:252, 2009. (3) B. S. Weir and P. R. Johnston. Mycotaxon 111:209, 2010.
EP1- and EP3-Receptors Mediate Prostaglandin E2–Induced Constriction of Porcine Large Cerebral Arteries
Authors: Jadhav Vikram , Jabre Anthony , Lin Shinn-Zong , Lee Tony Jer-Fu
Published: May 2011

Prostaglandin E2 (PGE2) has been shown to dilate and constrict the systemic vascular beds, including cerebral vessels. The exact mechanism of PGE2-induced cerebral vasoconstriction, however, is less clarified. The authors' preliminary studies showed that PGE2 exclusively constricted the adult porcine basilar arteries. The present study, therefore, was designed to examine the receptor mechanisms involved in PGE2-induced constriction of large cerebral arteries in the adult pig. Results from an in vitro tissue-bath study indicated that PGE2 and its agonists 17-phenyl trinor PGE2 (17-PGE2), sulprostone (EP1/EP3 receptor agonists), and 11-deoxy-16,16-dimethyl PGE2 (11-PGE2, an EP2/EP3-receptor agonist) induced exclusive constriction, which was not affected by endothelium denudation or cold-storage denervation of perivascular nerves. The constriction induced by PGE2, 17-PGE2, and sulprostone, but not by potassium chloride, was blocked by SC-19220 (a selective EP1-receptor antagonist), AH-6809 (an EP1/EP2-receptor antagonist), and U-73122 and neomycin (phospholipase C inhibitors). AH-6809, however, did not affect 11-PGE2–induced contraction. These results suggest that the contraction was not mediated by the EP2-receptor, but was mediated by EP1- and EP3-receptors. Furthermore, EP1-receptor immunoreactivities were found across the entire medial smooth muscle layers, whereas EP3-receptor immunoreactivities were limited to the outer smooth muscle layer toward the adventitia. Western blotting also showed the presence of EP1- and EP3-receptor proteins in cultured primary cerebral vascular smooth muscle cells. In conclusion, PGE2 exclusively constricts the adult porcine large cerebral arteries. This constriction is mediated by phosphatidyl–inositol pathway via activation of EP1- and EP3-receptors located on the smooth muscle cells. These two receptor subtypes may play important roles in physiologic and pathophysiologic control of cerebral vascular tone.
Cerebral Vascular and Metabolic Response to Sustained Systemic Inflammation in Ovine Traumatic Brain Injury
Authors: Stubbe Henning D. , Greiner Christoph , Van Aken Hugo , Rickert Christian H. , Westphal Martin , Wassmann Hansdetlef , Akcocuk Ali , Daudel Fritz , Erren Michael , Hinder Frank
Published: May 2011

Traumatic brain injury (TBI) is frequently accompanied by a systemic inflammatory response secondary to multiple trauma, shock, or infections. This study investigated the impact of sustained systemic inflammation on cerebral hemodynamics and metabolism in ovine traumatic brain injury. Fifteen sheep were investigated for 14 hours. Head injury was induced with a nonpenetrating stunner in anesthetized, ventilated animals. One group (TBI/Endo, n = 6) subsequently received a continuous endotoxin infusion for 12 hours, whereas a second group (TBI, n = 6) received the carrier. Three instrumented animals served as sham controls. Head impact significantly increased intracranial pressure from 9 ± 4 mm Hg to 21 ± 15 mm Hg (TBI/Endo) and from 10 ± 3 mm Hg to 24 ± 19 mm Hg (TBI) (means ± SD). Internal carotid blood flow increased and cerebral vascular resistance decreased ( P < 0.05) during the hyperdynamic inflammatory response between 10 and 14 hours in the TBI/Endo group, whereas these parameters were at baseline level in the TBI group. Intracranial pressure remained unchanged during this period, but increased during hypercapnia. The CMRO2, PaCO2, and arterial hematocrit values were identical among the groups between 10 and 14 hours. It is concluded that chronic endotoxemia in ovine traumatic brain injury was associated with cerebral vasodilation uncoupled from global brain metabolism. Different mechanisms appear to induce cerebral vasodilation in response to inflammation and hypercapnia.
Transcript amplification from single bacterium for transcriptome analysis
Authors: Kang Yun , Norris Michael H. , Zarzycki-Siek Jan , Nierman William C. , Donachie Stuart P. , Hoang Tung T.
Published: May 2011

Total transcript amplification (TTA) from single eukaryotic cells for transcriptome analysis is established, but TTA from a single prokaryotic cell presents additional challenges with much less starting material, the lack of poly(A)-tails, and the fact that the messages can be polycistronic. Here, we describe a novel method for single-bacterium TTA using a model organism, Burkholderia thailandensis, exposed to a subinhibitory concentration of the antibacterial agent, glyphosate. Utilizing a B. thailandensis microarray to assess the TTA method showed low fold-change bias (less than twofold difference and Pearson correlation coefficient R ≈ 0.87–0.89) and drop-outs (4%–6% of 2842 detectable genes), compared with data obtained from the larger-scale nonamplified RNA samples. Further analysis of the microarray data suggests that B. thailandensis, when exposed to the aromatic amino acid biosynthesis inhibitor glyphosate, induces (or represses) genes to possibly recuperate and balance the intracellular amino acid pool. We validated our single-cell microarray data at the multi-cell and single-cell levels with lacZ and gfp reporter-gene fusions, respectively. Sanger sequencing of 192 clones generated from the TTA product of a single cell, with and without enrichment by elimination of rRNA and tRNA, detected only B. thailandensis sequences with no contamination. These data indicate that RNA-seq of TTA from a single cell is possible using this novel method.
Early marine migration of European silver eel Anguilla anguilla in northern Norway
Authors: Davidsen J. G. , Finstad B. , ØKland F. , Thorstad E. B. , Mo T. A. , Rikardsen A. H.
Published: May 2011

To study the migratory behaviour in wild northern European silver eel Anguilla anguilla during sea entry and early marine migration, 32 individuals were tagged with acoustic transmitters and registered at four automatic listening station arrays from the mouth of the north Norwegian River Alta and throughout the Alta Fjord. The A. anguilla entered the fjord during all parts of the tidal cycle and did not seem to utilize the outgoing tidal currents. They migrated mainly during the night, in both the river mouth and the fjord. On average, they spent 2·7 days travelling from the river mouth to the outermost array, 31 km from the river mouth, corresponding to an average migratory speed of 0·5 km h−1. The A. anguilla generally migrated in the central part of the fjord and in the uppermost 10–25% of the water column, but with frequent dives to greater depths. Already 4 km after sea entry, A. anguilla were observed diving deeper than 130 m within 20–30 min periods. Hence, this study demonstrated that A. anguilla may perform an active diving behaviour during the early marine migration. The study took place in a pristine area with a minimum of anthropogenic interventions and by individuals from a population still uninfected by the introduced parasite Anguillicoloides crassus. The results may therefore be used as a baseline for future studies of the A. anguilla early marine migration.
Influenza A‐induced rhabdomyolysis and acute kidney injury complicated by posterior reversible encephalopathy syndrome
Authors: Fearnley R. A. , Lines S. W. , Lewington A. J. P. , Bodenham A. R.
Published: May 2011

We report a case of Influenza A‐induced rhabdomyolysis causing acute kidney injury in a young adult female who required invasive ventilation and renal replacement therapy. This case was further complicated by posterior reversible encephalopathy syndrome. Although this represents an extremely rare neurological complication of Influenza A infection, an appreciation of the condition and its management is important, given the high numbers of critically ill patients recently affected by H1N1 Influenza A in intensive care units in the UK.
Disabled‐2 modulates homotypic and heterotypic platelet interactions by binding to sulfatides
Authors: Welsh John D. , Charonko John J. , Salmanzadeh Alireza , Drahos Karen E. , Shafiee Hadi , Stremler Mark A. , Davalos Rafael V. , Capelluto Daniel G. S. , Vlachos Pavlos P. , Finkielstein Carla V.
Published: May 2011

Disabled‐2 (Dab2) inhibits platelet aggregation by competing with fibrinogen for binding to the αIIbβ3 integrin receptor, an interaction that is modulated by Dab2 binding to sulfatides at the outer leaflet of the platelet plasma membrane. The disaggregatory function of Dab2 has been mapped to its N‐terminus phosphotyrosine‐binding (N‐PTB) domain. Our data show that the surface levels of P‐selectin, a platelet transmembrane protein known to bind sulfatides and promote cell‐cell interactions, are reduced by Dab2 N‐PTB, an event that is reversed in the presence of a mutant form of the protein that is deficient in sulfatide but not in integrin binding. Importantly, Dab2 N‐PTB, but not its sulfatide binding‐deficient form, was able to prevent sulfatide‐induced platelet aggregation when tested under haemodynamic conditions in microfluidic devices at flow rates with shear stress levels corresponding to those found in vein microcirculation. Moreover, the regulatory role of Dab2 N‐PTB extends to platelet‐leucocyte adhesion and aggregation events, suggesting a multi‐target role for Dab2 in haemostasis.
Krüppel‐like Factor 4 activates HBG gene expression in primary erythroid cells
Authors: Kalra Inderdeep S. , Alam Md M. , Choudhary Pankaj K. , Pace Betty S.
Published: May 2011

The SP1/Krüppel‐like Factor (SP1/KLF) family of transcription factors plays a role in diverse cellular processes, including proliferation, differentiation and control of gene transcription. The discovery of KLF1 (EKLF), a key regulator of HBB (β‐globin) gene expression, expanded our understanding of the role of KLFs in erythropoiesis. In this study, we investigated a mechanism of HBG (γ‐globin) regulation by KLF4. siRNA‐mediated gene silencing and enforced expression of KLF4 in K562 cells substantiated the ability of KLF4 to positively regulate endogenous HBG gene transcription. The physiological significance of this finding was confirmed in primary erythroid cells, where KLF4 knockdown at day 11 significantly attenuated HBG mRNA levels and enforced expression at day 28 stimulated the silenced HBG genes. In vitro binding characterization using the γ‐CACCC and β‐CACCC probes demonstrated KLF4 preferentially binds the endogenous γ‐CACCC, while CREB binding protein (CREBBP) binding was not selective. Co‐immunoprecipitation studies confirmed protein‐protein interaction between KLF4 and CREBBP. Furthermore, sequential chromatin immunoprecipitation assays showed co‐localization of both factors in the γ‐CACCC region. Subsequent luciferase reporter studies demonstrated that KLF4 trans‐activated HBG promoter activity and that CREBBP enforced expression resulted in gene repression. Our data supports a model of antagonistic interaction of KLF4/CREBBP trans‐factors in HBG regulation.
Review of the cardiac long‐term effects of therapy for Hodgkin lymphoma
Authors: Ng Andrea K.
Published: May 2011

Patients diagnosed with Hodgkin lymphoma have a high cure rate. However, long‐term survivors of the disease are at significantly increased risk for a number of late effects, with cardiovascular disease being the most common non‐malignant cause of death in these patients. This review summarizes the available data regarding the types of cardiac complications, timing of their onset in relationship to initial treatment, associated risk factors, and available studies on the role of screening for subclinical cardiac disease. Given the known correlation between the extent of Hodgkin lymphoma therapy and subsequent cardiac risks, current trials investigating treatment reduction, including using lower radiation dose, smaller radiation field size and abbreviated chemotherapy will hopefully help in limiting cardiac toxicity. Screening for and aggressive management of traditional cardiac risk factors are also important strategies in reducing risks of cardiac disease in long‐term Hodgkin lymphoma survivors.
The effect of extremely preterm birth on attachment organization in late adolescence
Authors: Hallin A.‐L. , Bengtsson H. , Frostell A. S. , Stjernqvist K.
Published: May 2011

Background  Prior studies have examined the impact of preterm birth on the quality of the attachment relationship to the mother in infancy, but few have examined extremely preterm born infants and almost no data have been reported on prematurity and its impact on the attachment organization attained after childhood.

Methods  Thirty‐nine adolescents born extremely preterm and 39 full‐term born control participants were assessed with the Adult Attachment Interview.

Results  The prematurely born showed lower scores regarding measures of attachment security and, in particular, a higher proportion of insecure dismissive patterns. This difference seemed to be clear and persistent even when controlled for intelligence and socio‐economic variables.

Conclusions  Because insecure attachment as well as prematurity may be considered as significant risk factors for developing psychopathology, they deserve careful attention in future research and clinical follow‐ups.
Influence of yeast strain, immobilisation and ageing time on the changes of free amino acids and amino acids in peptides in bottle‐fermented sparkling wines obtained from Vitis vinifera cv. Emir
Authors: Bozdogan Adnan , Canbas Ahmet
Published: May 2011

This paper reports the influence of yeast strain, immobilisation and ageing time on the free amino acids and amino acids in peptides of sparkling wine made by the traditional method from the Emir grape variety over a period of 365 days in vintages 2004 and 2005. Four sparkling wines were obtained from the same base wine using yeast strains (both immobilised and free Saccharomyces bayanus and Saccharomyces oviformis). The analysis of variance and cluster revealed that there were significant differences between free amino acids and amino acids in peptides due to ageing time. However, the yeast strain affected most of the free amino acids and amino acids in peptides in only the 2004 vintage. The total amount of free amino acids was higher in the wine made with the S. oviformis compared to S. bayanus. Furthermore, there were no significant differences between the use of immobilised and free yeast in cases of free amino acids and amino acids in peptides.
Fatty acid composition and biological activities of volatiles from fruits of two Tunisian olive cultivars
Authors: Brahmi Faten , Dabbou Samia , Flamini Guido , Edziri Hayet , Mastouri Maha , Hammami Mohamed
Published: May 2011

This study investigates volatile compounds, fatty acid composition and antioxidant, antibacterial and antifungal activities of fruits from two olive cultivars (Chemlali and Neb Jmel). Fatty acid profiles varied significantly between cultivars (cvs) where Neb Jmel seem to have higher contents of palmitic and oleic acids (16.4% and 66.4%, respectively) and lower of linoleic acid (9.4%). The volatile profile indicated the apparent difference between cvs. In fact, the main components detected in Chemlali cv. were (E,E)‐2,4‐decadienal (23.0%), (E,Z)‐2,4‐decadienal (14.9%) and nonanal (6.7%), while 3‐ethenylpyridine (15.5%), (E)‐2‐decenal (14.4%) and (E)‐2‐undecenal (7.0%) were the major components in Neb Jmel cv. Furthermore, these volatiles were subjected to screening for their possible antioxidant activities where volatiles from Neb Jmel fruits were found to be better. Results presented here may suggest that the volatiles fraction of two cultivars possess antimicrobial and antifungal activities.
Active packaging of ground beef patties by edible zein films incorporated with partially purified lysozyme and Na2EDTA
Authors: Ünalan İlke Uysal , Korel Figen , Yemenicioğlu Ahmet
Published: May 2011

In this study, antimicrobial activity of zein films incorporated with partially purified lysozyme and disodium ethylenediaminetetraacetic acid (Na2EDTA) has been tested on selected pathogenic bacteria and refrigerated ground beef patties. The developed films containing 700 μg cm−2 lysozyme and 300 μg cm−2 Na2EDTA showed antimicrobial activity on Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium. The application of lysozyme and Na2EDTA incorporated zein films on beef patties significantly decreased total viable counts (TVC) and total coliform counts after 5 days of storage compared to those of control patties (P < 0.05). Zein films incorporated with lysozyme and Na2EDTA or Na2EDTA alone significantly slowed down the oxidative changes in patties during storage (P < 0.05). Redness indices of patties coated with zein films were significantly lower than those of uncoated control patties during storage (P < 0.05). This study demonstrated the potential usage of zein films containing lysozyme and Na2EDTA for active packaging of refrigerated meat products.
Nondestructive tests for measuring the firmness of guava fruit stored and treated with methyl jasmonate and calcium chloride
Authors: Barriga‐Téllez Leslie Malleli , Garnica‐Romo Ma. Guadalupe , Aranda‐Sánchez Jorge Isidro , Correa Gabriel Arroyo , Bartolomé‐Camacho María Carmen , Martínez‐Flores Héctor Eduardo
Published: May 2011

Ripening is one of the most important processes to occur in fruits and involves changes in colour, flavour and texture. An important goal in quality control of fruits is to substitute traditional sensory testing methods with reliable and quantitative methods. In this study, methyl jasmonate (MJ) (220 μL L−1) and calcium chloride (at 1%) were applied to guava fruits stored at 6 °C. The compression test (CT) and acoustic impact test were used to monitor the shelf life of guavas. The results obtained using both techniques showed that Young’s modulus diminishes as a function of time in all samples; however, the texture of samples treated for 20 days with MJ deteriorated unacceptably, a condition which did not occur in the samples treated with calcium chloride. The control samples had a shelf life of 20 days. In conclusion, it appears that the acoustic impact test is more appropriate than the CT and has the additional advantage of being a nondestructive technique.
Before the cradle and beyond the grave: a lifespan/settings‐based framework for health promotion
Authors: Whitehead Dean
Published: May 2011

Aim.  To develop a unique framework which combines the concepts of settings and lifespan where they are applied to health promotion.

Background.  The influential World Health Organisation’s 1986 Ottawa Charter for Health Promotion supported certain settings being nominated as unique social systems for enabling specific health promotion activity. These initially included a whole raft of proposed settings ranging from the micro to macro; these at the time mainly being hospitals, communities, schools, workplaces, cities, villages, islands and the home and family. Several other settings have since also been added to the list – which now include health‐promoting universities and health‐promoting prisons. Most of the mentioned settings have in more recent times being acknowledged in the nursing literature.

Design.  Discursive.

Method.  A critical examination and exploration of the existing health promotion literature related to both settings and lifespan.

Results.  It is possible to combine the related, but hitherto unexplored, concepts of health promotion settings and lifespan. This has resulted in a useable framework to further assist practitioners with their health promotion work.

Conclusion.  What has not yet surfaced in both the nursing and the general health promotion literature is that most settings can be linked as a whole, not just by their geographical location and proximity to each other, but also to the fact that they tend to follow a linear direction that ranges across the total lifespan.

Relevance to clinical practice.  Viewing health promotion in the way that this framework proposes further assists in locating and clarifying the often confused and contested position of health promotion in nursing.
Phylogeography and genetic structure of the red‐legged partridge (Alectoris rufa): more evidence for refugia within the Iberian glacial refugium
Authors: FERRERO M. ESTER , BLANCO‐AGUIAR JOSE A. , LOUGHEED STEPHEN C. , SÁNCHEZ‐BARBUDO INÉS , De NOVA PEDRO J. G. , VILLAFUERTE RAFAEL , DÁVILA JOSÉ A.
Published: May 2011

The Pleistocene climatic oscillations promoted the diversification in avian species during the last glacial period. The red‐legged partridge (Alectoris rufa, Family Phasianidae) has a large natural distribution extending from the Mediterranean to humid temperate zones. However, the genetic structure for this species is unknown. The present study investigates the phylogeography, genetic structure and demographic history of A. rufa across its distribution, employing both mitochondrial DNA control region sequences and nuclear microsatellite loci. Our results propose that this species was greatly affected by Pleistocene glaciations. The mismatch analyses suggest that the current populations resulted from post‐glacial expansion and subsequent differentiation resulting in five diagnosable genetic clusters: Southwestern, Central‐eastern, Northwestern, Balearic and French and Italian. Further, we found evidence of three glacial refugia within the currently recognized Iberian glacial refugium. The intraspecific structure revealed by both maternal and biparental phylogeographic analyses was not resolved in the phylogenetic analyses. Based on all considerations, we recommended that five management units be recognized.
More than meets the eye: detecting cryptic microgeographic population structure in a parasite with a complex life cycle
Authors: CRISCIONE CHARLES D. , VILAS ROMÁN , PANIAGUA ESPERANZA , BLOUIN MICHAEL S.
Published: May 2011

Nonrandom recruitment of parasites among hosts can lead to genetic differentiation among hosts and mating dynamics that promote inbreeding. It has been hypothesized that strictly aquatic parasites with intermediate hosts will behave as panmictic populations among hosts because ample opportunity exists for random mixing of unrelated individuals during transmission to the definitive host. A previous allozyme study on the marine trematode Lecithochirium fusiforme did not support this hypothesis; in that, there was genetic differentiation among, and significant heterozygote deficiencies within, definitive hosts. We revisit this system and use microsatellites to obtain multilocus genotypes. Our goal was to determine whether cryptic subgroups and/or the presence of clones could account for the apparent deviation from ‘panmixia’. We find strong evidence for cryptic subdivision (three genetic clusters) that causes the Wahlund effect and differentiation among definitive hosts. After accounting for these cryptic groups, we see panmictic genetic structure among definitive hosts that is consistent with the ‘high mixing in aquatic habitats’ hypothesis. We see evidence for cotransmission of clones in all three clusters, but this level of clonal structure did not have a major impact in causing deviations from Hardy–Weinberg equilibrium, and only affected genetic differentiation among hosts in one cluster. A cursory examination of the data may have led to incorrect conclusions about nonrandom transmission. However, it is obvious in this system that there is more than meets the eye in relation to the actual make‐up of parasite populations. In general, the methods we employ will be useful for elucidating hidden patterns in other organisms where cryptic structure may be common (e.g. those with limited morphology or complex life histories).