bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural reorganization of the interleukin-7 signaling complex
Authors: McElroy Craig A. , Holland Paul J. , Zhao Peng , Lim Jae-Min , Wells Lance , Eisenstein Edward , Walsh Scott T. R.
Published: January 2012

We report here an unliganded receptor structure in the common gamma-chain (γ
c
) family of receptors and cytokines. The crystal structure of the unliganded form of the interleukin-7 alpha receptor (IL-7Rα) extracellular domain (ECD) at 2.15 Å resolution reveals a homodimer forming an “X” geometry looking down onto the cell surface with the C termini of the two chains separated by 110 Å and the dimer interface comprising residues critical for IL-7 binding. Further biophysical studies indicate a weak association of the IL-7Rα ECDs but a stronger association between the γ
c
/IL-7Rα ECDs, similar to previous studies of the full-length receptors on CD4
+
T cells. Based on these and previous results, we propose a molecular mechanism detailing the progression from the inactive IL-7Rα homodimer and IL-7Rα–γ
c
heterodimer to the active IL-7–IL-7Rα–γ
c
ternary complex whereby the two receptors undergo at least a 90° rotation away from the cell surface, moving the C termini of IL-7Rα and γ
c
from a distance of 110 Å to less than 30 Å at the cell surface. This molecular mechanism can be used to explain recently discovered IL-7– and γ
c
-independent gain-of-function mutations in IL-7Rα from B- and T-cell acute lymphoblastic leukemia patients. The mechanism may also be applicable to other γ
c
receptors that form inactive homodimers and heterodimers independent of their cytokines.
Carbon availability triggers fungal nitrogen uptake and transport in arbuscular mycorrhizal symbiosis
Authors: Fellbaum Carl R. , Gachomo Emma W. , Beesetty Yugandhar , Choudhari Sulbha , Strahan Gary D. , Pfeffer Philip E. , Kiers E. Toby , Bücking Heike
Published: January 2012

The arbuscular mycorrhizal (AM) symbiosis, formed between the majority of land plants and ubiquitous soil fungi of the phylum Glomeromycota, is responsible for massive nutrient transfer and global carbon sequestration. AM fungi take up nutrients from the soil and exchange them against photosynthetically fixed carbon (C) from the host. Recent studies have demonstrated that reciprocal reward strategies by plant and fungal partners guarantee a “fair trade” of phosphorus against C between partners [Kiers ET, et al. (2011) Science 333:880–882], but whether a similar reward mechanism also controls nitrogen (N) flux in the AM symbiosis is not known. Using mycorrhizal root organ cultures, we manipulated the C supply to the host and fungus and followed the uptake and transport of N sources in the AM symbiosis, the enzymatic activities of arginase and urease, and fungal gene expression in the extraradical and intraradical mycelium. We found that the C supply of the host plant triggers the uptake and transport of N in the symbiosis, and that the increase in N transport is orchestrated by changes in fungal gene expression. N transport in the symbiosis is stimulated only when the C is delivered by the host across the mycorrhizal interface, not when C is supplied directly to the fungal extraradical mycelium in the form of acetate. These findings support the importance of C flux from the root to the fungus as a key trigger for N uptake and transport and provide insight into the N transport regulation in the AM symbiosis.
Predictable and efficient carbon sequestration in the North Pacific Ocean supported by symbiotic nitrogen fixation
Authors: Karl David M. , Church Matthew J. , Dore John E. , Letelier Ricardo M. , Mahaffey Claire
Published: January 2012

The atmospheric and deep sea reservoirs of carbon dioxide are linked via physical, chemical, and biological processes. The last of these include photosynthesis, particle settling, and organic matter remineralization, and are collectively termed the “biological carbon pump.” Herein, we present results from a 13-y (1992–2004) sediment trap experiment conducted in the permanently oligotrophic North Pacific Subtropical Gyre that document a large, rapid, and predictable summertime (July 15–August 15) pulse in particulate matter export to the deep sea (4,000 m). Peak daily fluxes of particulate matter during the summer export pulse (SEP) average 408, 283, 24.1, 1.1, and 67.5 μmol·m
−2
·d
−1
for total carbon, organic carbon, nitrogen, phosphorus (PP), and biogenic silica, respectively. The SEP is approximately threefold greater than mean wintertime particle fluxes and fuels more efficient carbon sequestration because of low remineralization during downward transit that leads to elevated total carbon/PP and organic carbon/PP particle stoichiometry (371:1 and 250:1, respectively). Our long-term observations suggest that seasonal changes in the microbial assemblage, namely, summertime increases in the biomass and productivity of symbiotic nitrogen-fixing cyanobacteria in association with diatoms, are the main cause of the prominent SEP. The recurrent SEP is enigmatic because it is focused in time despite the absence of any obvious predictable stimulus or habitat condition. We hypothesize that changes in day length (photoperiodism) may be an important environmental cue to initiate aggregation and subsequent export of organic matter to the deep sea.
Drivers and hotspots of extinction risk in marine mammals
Authors: Davidson Ana D. , Boyer Alison G. , Kim Hwahwan , Pompa-Mansilla Sandra , Hamilton Marcus J. , Costa Daniel P. , Ceballos Gerardo , Brown James H.
Published: January 2012

The world's oceans are undergoing profound changes as a result of human activities. However, the consequences of escalating human impacts on marine mammal biodiversity remain poorly understood. The International Union for the Conservation of Nature (IUCN) identifies 25% of marine mammals as at risk of extinction, but the conservation status of nearly 40% of marine mammals remains unknown due to insufficient data. Predictive models of extinction risk are crucial to informing present and future conservation needs, yet such models have not been developed for marine mammals. In this paper, we: (i) used powerful machine-learning and spatial-modeling approaches to understand the intrinsic and extrinsic drivers of marine mammal extinction risk; (ii) used this information to predict risk across all marine mammals, including IUCN “Data Deficient” species; and (iii) conducted a spatially explicit assessment of these results to understand how risk is distributed across the world's oceans. Rate of offspring production was the most important predictor of risk. Additional predictors included taxonomic group, small geographic range area, and small social group size. Although the interaction of both intrinsic and extrinsic variables was important in predicting risk, overall, intrinsic traits were more important than extrinsic variables. In addition to the 32 species already on the IUCN Red List, our model identified 15 more species, suggesting that 37% of all marine mammals are at risk of extinction. Most at-risk species occur in coastal areas and in productive regions of the high seas. We identify 13 global hotspots of risk and show how they overlap with human impacts and Marine Protected Areas.
Vezf1 protein binding sites genome-wide are associated with pausing of elongating RNA polymerase II
Authors: Gowher Humaira , Brick Kevin , Camerini-Otero R. Daniel , Felsenfeld Gary
Published: January 2012

The protein Vezf1 plays multiple roles important for embryonic development. In Vezf1−/−mouse embryonic stem (mES) cells, our earlier data showed widespread changes in gene-expression profiles, including decreased expression of the full-length active isoform of Dnmt3b methyltransferase and concomitant genome-wide reduction in DNA methylation. Here we show that in HeLaS3 cells there is a strong genome-wide correlation between Vezf1 binding and peaks of elongating Ser2-P RNA polymerase (Pol) ll, reflecting Vezf1-dependent slowing of elongation. In WT mES cells, the elongating form of RNA pol II accumulates near Vezf1 binding sites within thednmt3bgene and at several other Vezf1 sites, and this accumulation is significantly reduced at these sites inVezf1−/−mES cells. Depending upon genomic location, Vezf1-mediated Pol II pausing can have different regulatory roles in transcription and splicing. We find examples of genes in which Vezf1 binding sites are located near cassette exons, and in which loss of Vezf1 leads to a change in the relative abundance of alternatively spliced messages. We further show that Vezf1 interacts with Mrg15/Mrgbp, a protein that recognizes H3K36 trimethylation, consistent with the role of histone modifications at alternatively spliced sites.
Chondroitinase ABC promotes selective reactivation of somatosensory cortex in squirrel monkeys after a cervical dorsal column lesion
Authors: Bowes Charnese , Massey James M. , Burish Mark , Cerkevich Christina M. , Kaas Jon H.
Published: January 2012

After large but incomplete lesions of ascending dorsal column afferents in the cervical spinal cord, the hand representation in the contralateral primary somatosensory cortex (area 3b) of monkeys is largely or completely unresponsive to touch on the hand. However, after weeks of spontaneous recovery, considerable reactivation of the hand territory in area 3b can occur. Because the reactivation process likely depends on the sprouting of remaining axons from the hand in the cuneate nucleus of the lower brainstem, we sought to influence cortical reactivation by treating the cuneate nucleus with an enzyme, chondroitinase ABC, that digests perineuronal nets, promoting axon sprouting. Dorsal column lesions were placed at a spinal cord level (C5/C6) that allowed a portion of ascending afferents from digit 1 to survive in squirrel monkeys. After 11–12 wk of recovery, the contralateral forelimb cortex was reactivated by stimulating digit 1 more extensively in treated monkeys than in control monkeys. The results are consistent with the proposal that the treatment enhances the sprouting of digit 1 afferents in the cuneate nucleus and that this sprouting allowed these preserved inputs to activate cortex more effectively.
Barack Obama, being sharp
Authors: Lempert Michael
Published: January 2012

Gesture in political oratory and debate is renowned for its nonreferential indexical functions, for the way it purportedly can indicate qualities of speaker and materialize acts of persuasion — functions famously addressed in Quintilian’s classic writings but understudied today. I revisit this problematic through a case study of precision-grip (especially thumb to tip of forefinger) in Barack Obama’s debate performances (2004–2008). Cospeech gesture can index valorized attributes of speaker — not directly but through orders of semiotic motivation. In terms of first-order indexicality, precision-grip highlights discourse in respect of information structure, indicating focus. In debate, precision grip has undergone a degree of conventionalization and has reemerged as a second-order pragmatic resource for performatively “making a ‘sharp’, effective point.” Repetitions and parallelisms of precision grip in debate can, in turn, exhibit speaker-attributes, such as being argumentatively ‘sharp’, and from there may even partake in candidate branding.
Synthesis of nano-sized hydroxyapatite by ultrasound irradiation
Authors: Kojima Y , Kitazawa K , Nishimiya N
Published: January 2012

Ultrasound irradiation is an effective means of synthesizing fine particles by promoting contact between ions in a solution. We previously reported the synthesis of nano-sized amorphous calcium carbonate particles (specific surface area: 70 m2/g) using this method. The present study focused on the production of nano-sized hydroxyapatite (HAp) particles with a high specific surface area using ultrasound irradiation. The initial Ca/P atomic ratio was adjusted from 1.00 to 2.00 and the effects on the resulting HAp particles was investigated. HAp particles were found to be easily formed within 5 min of the start of the reaction, and were confirmed to have a single phase using X-ray diffraction analysis. The maximum specific surface area of the particles was approximately 130 m2/g.
Preparation and performance of a sulfur/graphene composite for rechargeable lithium-sulfur battery
Authors: Zhang Feifei , Dong Yunhui , Huang Yun , Huang Gang , Zhang Xinbo , Wang Limin
Published: January 2012

The lithium-sulfur (Li-S) battery is a promising electrochemical system that has high theoretical capacity. The sulfur/graphene nanosheets (S/GNS) composite is prepared through thermal reduction between the sulfur (S) and graphene oxide (GO). The morphology and composition of the composite are analyzed by means of x-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopic (EDS) characterization. It is found that the element S distributed uniformly between the layers of GNS. Graphene with a two-dimensional structure of carbon atoms is employed as a conductive and absorbing agent for the S cathode materials of rechargeable Li-S battery. The S/GNS composite cathode shows a specific electrochemical capacity, which is about 1598 mAh g−1S at the initial discharge and remains above 670 mAh g−1after 80 cycles.
Sintering and mechanical properties of gadolinium-doped ceria ceramics
Authors: Yasuda K , Uemura K , Shiota T
Published: January 2012

Gadolinium-doped ceria (GDC) ceramics were made by sintering at various temperatures from 1000°C to 1400°C in air. The true density and apparent density were measured to calculate the relative density of GDC ceramics. The change in relative density revealed that densification of GDC ceramics increased up to 1200°C, and thereafter turned downward. It was suggested that pores were formed at 1300°C and 1400°C due to non-stoichiometry of ceria. JIS-type specimens were cut from the sintered body and tested by 4-point bending. Young's modulus and bending strength decreased with increasing the sintering temperature from 1200°C to 1400°C, corresponding to the change in the relative density.
Controlling new drugs under marketing regulations
Authors: Hughes Brendan , Winstock Adam R.
Published: January 2012

Aims  The rapid emergence of myriad substances openly marketed as ‘legal highs’ is straining traditional drug control systems which require time and basic scientific data on harms to react, presenting governments with the dilemma of no response or a disproportionate response. Some countries have side‐stepped this using novel policy and legislative approaches. Should other countries consider them?

Methods  We review the different laws invoked to stop the open sale of new psychoactive substances, focusing on the European Union (EU).

Results  Some countries have designed new catch‐all control systems, or faster systems to classify substances as drugs. Others have enforced consumer safety or medicines legislation to stop the open sale of these products. The latter originate from harmonization of the internal market of the EU. Rigorous, objective evaluation is required, but first results suggest that these have been effective, while avoiding criminalization of users.

Conclusions  Every EU country should have existing laws for protecting public health that can be applied swiftly yet proportionately to new drugs appearing on the open market with minimum political involvement. It seems the key is the speed, not the weight, of response. Given support for their enforcement mechanisms, these systems might be as effective and more efficient than the old ones.
The long‐term risk of malignancy following a diagnosis of coeliac disease or dermatitis herpetiformis: a cohort study
Authors: Grainge M. J. , West J. , Solaymani‐Dodaran M. , Card T. R. , Logan R. F. A.
Published: January 2012

Background

People with coeliac disease are known to be at increased risk of malignancy; however, long‐term risks of malignancy beyond 10–15 years are largely unstudied.

Aim

To estimate how long an increased risk of malignancy among coeliac disease patients persists following diagnosis and treatment, using data from a cohort with an average follow‐up of 25 years.

Methods

People with coeliac disease diagnosed in the Lothian region of Scotland, United Kingdom, were followed up from January 1970 or the date of coeliac disease diagnosis (whichever was later) until the first occurrence of death, emigration, cancer diagnosis or the end of 2004. Standardised incidence ratios were calculated to compare the cancer incidence rates among this group with those from the population of Scotland.

Results

Overall, the risk of any malignancy in coeliac disease patients compared with the general population was increased 40% [standardised incidence ratio (SIR) = 1.41; 95% CI 1.09–1.78]. An increased risk for cancer overall persisted for up to 15 years, beyond which no overall increase in malignancy risk was observed, although the risk of non‐Hodgkin's lymphoma remained raised beyond 15 years (SIR = 5.15; 95% CI 1.40–13.2). In total, there were 14 non‐Hodgkin's lymphomas in the cohort, providing an overall incidence of 1.3 per 1000 person‐years.

Conclusions

The overall risk of malignancy in coeliac patients declines with time after diagnosis and is not significantly increased after 15 years. Most of the increased risk can be attributed to the development of haematological malignancies, despite their very low absolute rate of occurrence.
Characterisation of phenolic acids, flavonoids, proanthocyanidins and antioxidant activity of water extracts from seed coats of marama bean [Tylosema esculentum] – an underutilised food legume
Authors: Shelembe Jeremiah S. , Cromarty Duncan , Bester Megan J. , Minnaar Amanda , Duodu Kwaku G.
Published: January 2012

Freeze‐dried aqueous phenolic extracts with possible application as natural antioxidant functional food ingredients were prepared from marama bean seed coats by extracting with water. Phenolic acids, flavonoids and proanthocyanidins in the extracts were characterised by HPLC/MS. The major flavonoids were the flavanols methyl (epi)afzelechin‐3‐O‐gallate (40%) and methyl (epi)catechin‐3‐O‐gallate (28%), and the major phenolic acid was gallic acid (10%). Proanthocyanidins in the extracts were predominantly prodelphinidins composed of epicatechin‐3‐O‐gallate and epigallocatechin present as major terminal and extension units and epigallocatechin‐3‐O‐gallate and epicatechin present as minor extension unit constituents. The polymer structure was found to be unique compared with other legumes because of the high percentage of galloylated units. Extracts showed a high DPPH free radical scavenging activity (707 μmol TE g−1), protective effect against AAPH‐induced human red blood cell haemolysis and copper‐catalysed human LDL oxidation suggesting that the extracts may have potential health benefits.
Physicochemical property changes in germinated brown rice flour from different storage periods of paddy rice
Authors: Songtip Parisut , Jangchud Kamolwan , Jangchud Anuvat , Tungtrakul Patcharee
Published: January 2012

This study revealed that the storage duration (2, 4, 6, 8, 10 and 12 months) of paddy rice and pH (3 and 6.8) of steeping water during germination were significantly influenced the physicochemical properties of germinated brown rice flour (GBRF). GBRF obtained at pH 3 vs. 6.8 provided the highest both reducing sugar content and free gamma‐aminobutyric acid (GABA) content (99.8 vs. 54.2 mg per 100 g flour respectively) as the paddy rice was stored for 8 months. The peak viscosity of GBRF obtained at pH 3 and 6.8 exhibited the lower values than that of non‐GBRF throughout the storage. From the principal component analysis, reducing sugar had a positive correlation with α‐amylase activity whereas a negative correlation was found with peak viscosity. GBRF from paddy rice stored for 8 months and germinated at pH 3 possessed the highest free GABA content, 50 times of the non‐GBRF, which can be further utilised in functional and healthy foods.
Evaluation of free radical‐scavenging activities of sweet potato protein and its hydrolysates as affected by single and combination of enzyme systems
Authors: Zhang Miao , Mu Tai‐Hua , Wang Yan‐Bo , Sun Min‐Jie
Published: January 2012

To evaluate the free radical‐scavenging activities of sweet potato protein (SPP) and its hydrolysates, single enzymes alone (alcalase, neutrase, protamex) or in combination with flavourzyme were employed. Compared with SPP, free radical‐scavenging activities of the resulting hydrolysates were all significantly increased (P < 0.05). Alcalase (ALC) hydrolysates exhibited the highest superoxide, hydroxyl and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical‐scavenging activities (P < 0.05), which was 18.71 ± 0.22, 27.13 ± 0.24 and 90.10 ± 0.15% respectively. Compared with SPP hydrolysates by single enzymes, the hydrolysates obtained by combination of enzyme systems exhibited higher degree of hydrolysis, but lower free radicals scavenging activities. In addition, the content of several antioxidant amino acid residues, such as His, Met, Tyr and Phe, in ALC hydrolysates was much higher compared with SPP and other hydrolysates using amino acids composition assay. The results suggested that peptides with free radical‐scavenging activity could be released from entire SPP chain via moderate enzymatic hydrolysis.
Interaction of aqueous extracts of two varieties of Yam tubers (Dioscorea spp) on some key enzymes linked to type 2 Diabetes in vitro
Authors: Adedayo Bukola C. , Ademiluyi Adedayo O. , Oboh Ganiyu , Akindahunsi Afolabi A.
Published: January 2012

This study sought to assess the effect of processing of yam flour [from white yam (Dioscorea rotundata) and water yam (Dioscorea alata)] to paste, on the antioxidant properties and inhibition of key enzymes linked to type‐2 diabetes (α‐amylase and α‐glucosidase). The phenolic content (phenol and flavonoid), antioxidant properties, α‐amylase and α‐glucosidase inhibitory properties of the aqueous extracts of the yam products were determined. Processing into paste caused significant (P < 0.05) percentage decrease in their total phenol and flavonoid content of the yam varieties. However, significant increase (P < 0.05) in the antioxidant properties of the yam varieties was observed after processing. Furthermore, the yam extracts inhibited α‐amylase and α‐glucosidase activities in vitro in a dose‐dependent parttern (1–4 mg mL−1), however, the pasting process caused significant (P < 0.05) decrease in the α‐amylase inhibitory and α‐glucosidase inhibitory activities. Therefore, processing the yam varieties into paste (browned) could potentially increase their antioxidant capacity as well as decreasing their α‐amylase and α‐glucosidase inhibitory properties.
Sorption isotherms of tapioca flour
Authors: Chisté Renan C. , Silva Priscila A. , Lopes Alessandra S. , da Silva Pena Rosinelson
Published: January 2012

The adsorption and desorption isotherms of tapioca flour was performed in the range of water activity (aw) from 0.22 to 0.92 at 25 °C, and the applicability of six mathematical models in data prediction was evaluated. The tapioca flour presented Type II isotherm (sigmoid), and the hysteresis effect was not observed. For the microbiological stability, the moisture of tapioca flour should not exceed 10.1%. The monolayer moisture content value indicates that the drying process of tapioca flour should not be conducted to obtain moisture levels lower than 4.92% to avoid unnecessary power consumption. The data fit showed that all mathematical models are able to predict the adsorption isotherm of tapioca flour, and the models of Handerson, Smith, GAB and BET are able to predict the desorption isotherm.
Informal care‐giving in advanced chronic obstructive pulmonary disease: lay knowledge and experience
Authors: Hynes Geralyn , Stokes Ann , McCarron Mary
Published: January 2012

Aim. The aim of this research was to explore the experiences of informal caregivers providing care in the home to a family member with chronic obstructive pulmonary disease.

Background. Advances in chronic obstructive pulmonary disease treatment, increasing emphasis on early discharge and home‐based care programmes enable those with advanced chronic obstructive pulmonary disease to remain at home. However, little is known about the consequences of these initiatives for informal caregivers.

Design. A qualitative exploratory approach.

Methods. Semi‐structured interviews with 11 family caregivers of people with advanced chronic obstructive pulmonary disease.

Results. Six core themes emerged including ‘then and now’ reflecting caregivers’ sense of loss and enmeshment with the illness experience and burden. The caregivers’ experience of illness burden included symptom, cultural and lifeworld meanings. Relationships between formal health care and healthcare professionals were rendered difficult by their perceived failure to look beyond acute exacerbations as discrete events rather than integral to the illness trajectory as a whole.

Conclusion. In failing to actively engage with caregivers, our current approaches to supporting persons with advanced chronic obstructive pulmonary disease may compound the care and illness burden experienced by family caregivers.

Relevance to practice. This study illustrates the potential for nursing to increase or lessen the caregiver burden through understanding the illness experience as one that is shared by both caregiver and care recipient.
First case of rabbit haemorrhagic disease in Canada: contaminated flying insect, vs. long‐term infection hypothesis
Authors: GOULD E.A.
Published: January 2012

Following the announcement of the first case of rabbit haemorrhagic disease (RHD) in a pet rabbit, housed indoors in Canada for more than 1 year, I submitted an evidence‐based explanation to ProMed explaining how RHD might have caused the death of ‘one’ of the three pet rabbits. I suggested with supporting evidence, that it may have been persistently infected with rabbit haemorrhagic disease virus (RHDV) which may have reactivated to cause the fatal disease. However, in this issue, Peacock et al. have proposed an alternative ‘hypothesis’ for the appearance of RHD in the pet rabbit. They hypothesise that a non‐identified insect or fomite might have become contaminated by a Chinese strain of RHDV somewhere in the US. This insect/fomite then flew or was windborne, from the US to Canada where it entered the house containing three pet rabbits and infected one of them. RHD is non‐endemic and is rarely reported in the US, where it has only been observed in domestic European rabbits, held in rabbitries. My proposal was based on the details provided by ProMed, the veterinary report from Canada, where RHDV has never previously been identified and the epidemiological, ecological and evolutionary history of RHDV which includes serological and phylogenetic evidence that ancestral RHDV lineages circulated before 1984. The flying insect hypothesis of Peacock et al. is based on circumstantial evidence and, I believe, has a lower probability of being correct than my evidence‐based long‐term infection proposal.
Multifocal haemorrhagic brain damage following hypoxia and blood pressure lability: case report and rat model
Authors: Pahlavan P. S. , Sutton W. , Buist R. J. , Del Bigio M. R.
Published: January 2012

P. S. Pahlavan, W. Sutton, R. J. Buist and M. R. Del Bigio (2012) Neuropathology and Applied Neurobiology38, 723–733

Multifocal haemorrhagic brain damage following hypoxia and blood pressure lability: case report and rat model

Aims: Haemorrhagic brain damage is frequently encountered as a complication of premature birth. Much less frequently, multifocal petechial haemorrhage is identified in asphyxiated term newborns. Our goal was to develop an experimental rat model to reproduce this pattern of brain damage. Methods: Neonatal rat pups were exposed to a 24‐h period of 10% or 8% hypoxia followed by a single dose of phenylephrine. Acute and subacute changes, as well as long‐term outcomes, were investigated by histology, brain magnetic resonance imaging and behavioural assessment. Immunostaining for vascular endothelial growth factor and caveolin‐1 was performed in the rat brains as well as in a 17‐day human case. Results: Small foci of haemorrhage were identified in almost all regions of the rat brain subjected to hypoxia plus phenylephrine, but not hypoxia alone. Exposure to 8% hypoxia was associated with more haemorrhagic foci than 10% hypoxia. With rare exceptions, the blood deposits were too small to be detected by magnetic resonance imaging. Altered immunohistochemical detection of vascular endothelial growth factor and caveolin‐1 in the child and the rat model suggests a role for blood–brain barrier compromise. There were no clear behavioural changes and no residual morphological abnormalities in the 78‐day follow‐up of the rats. Conclusions: We conclude that transient hypoxia, in a dose‐dependent manner, can weaken the vasculature and predispose to brain haemorrhage in the situation of labile blood pressure. Persistent hypoxia is likely to be important in the genesis of permanent severe brain damage.
Ternary effects on the gas exchange of isotopologues of carbon dioxide
Authors: FARQUHAR GRAHAM D. , CERNUSAK LUCAS A.
Published: January 2012

The ternary effects of transpiration rate on the rate of assimilation of carbon dioxide through stomata, and on the calculation of the intercellular concentration of carbon dioxide, are now included in standard gas exchange studies. However, the equations for carbon isotope discrimination and for the exchange of oxygen isotopologues of carbon dioxide ignore ternary effects. Here we introduce equations to take them into account. The ternary effect is greatest when the leaf‐to‐air vapour mole fraction difference is greatest, and its impact is greatest on parameters derived by difference, such as the mesophyll resistance to CO2 assimilation, rm. We show that the mesophyll resistance to CO2 assimilation has been underestimated in the past. The impact is also large when there is a large difference in isotopic composition between the CO2 inside the leaf and that in the air. We show that this partially reconciles estimates of the oxygen isotopic composition of CO2 in the chloroplast and mitochondria in the light and in the dark, with values close to equilibrium with the estimated oxygen isotopic composition of water at the sites of evaporation within the leaf.
Comparison of leaf gas exchange and stable isotope signature of water‐soluble compounds along canopy gradients of co‐occurring Douglas‐fir and European beech
Authors: BÖGELEIN REBEKKA , HASSDENTEUFEL MARTIN , THOMAS FRANK M. , WERNER WILLY
Published: January 2012

Combined δ13C and δ18O analyses of water‐soluble leaf and twig phloem material were used to determine intrinsic water‐use efficiency (iWUE) and variability of stomatal conductance at different crown positions in adult European beech (Fagus sylvatica) and Douglas‐fir (Pseudotsuga menziesii) trees. Simultaneous gas exchange measurements allowed evaluation of the differences in calculating iWUE from leaf or phloem water‐soluble compounds, and comparison with a semi‐quantitative dual isotope model to infer variability of net photosynthesis (An) between the investigated crown positions. Estimates of iWUE from δ13C of leaf water‐soluble organic matter (WSOM) outperformed the estimates from phloem compounds. In the beech crown, δ13C of leaf WSOM coincided clearly with gas exchange measurements. The relationship was not as reliable in the Douglas‐fir. The differences in δ18O between leaf and phloem material were found to correlate with stomatal conductance. The semi‐quantitative model approach was applicable for comparisons of daily average An between different crown positions and trees. Intracanopy gradients were more pronounced in the beech than in the Douglas‐fir, which reached higher values of iWUE at the respective positions, particularly under dry air conditions.
Short‐distance dispersal of splashed bacteria of Xanthomonas citri subsp. citri from canker‐infected grapefruit tree canopies in turbulent wind
Authors: Bock C. H. , Cook A. Z. , Parker P. E. , Gottwald T. R. , Graham J. H.
Published: January 2012

Citrus canker (Xanthomonas citri subsp. citri (Xcc)) can cause yield loss and trade restrictions. The pathogen is dispersed in rain splash and spread is promoted by wind. The goal of this study was to gain some insight into the properties of short‐distance splash dispersal of Xcc from ∼1·5 m‐tall cankered grapefruit canopies in turbulent wind, common during rainstorms in Florida. Turbulent wind up to 19·9 m s−1 was tested in five experiments. Bacteria flux density (BFD, bacteria cm−2 min−1) was quantified at heights of 30, 70, 110, 130 and 180 cm above ground, and at four horizontal points (17, 51, 85 and 119 cm) at each height across the direction of the wind 1 m downwind. BFD varied among experiments, but the lowest BFDs were consistently detected at the greatest sample height. Despite differences between experiments, the relationship between log BFD and sample height was consistently described by a linear function (P = 0·06–<0·0001, R2 = 0·75–>0·99). The BFD collected at the horizontal points across the wind path was variable. BFDs collected were sometimes significantly different, but no relationship was discernible. Stronger, turbulent wind resulted in greater BFD, with a linear function describing the relationship between log BFD and wind speed (P = 0·2–0·02, R2 = 0·94–0·96). Multiple regression analysis demonstrated predictability of the proportion of total bacteria collected (F = 141, P < 0·0001, d.f. = 3, R2 = 0·53).
Tandemly arranged chalcone synthase A genes contribute to the spatially regulated expression of siRNA and the natural bicolor floral phenotype in Petunia hybrida
Authors: Morita Yasumasa , Saito Ryoko , Ban Yusuke , Tanikawa Natsu , Kuchitsu Kazuyuki , Ando Toshio , Yoshikawa Manabu , Habu Yoshiki , Ozeki Yoshihiro , Nakayama Masayoshi
Published: January 2012

The natural bicolor floral traits of the horticultural petunia (Petunia hybrida) cultivars Picotee and Star are caused by the spatial repression of the chalcone synthase A (CHS‐A) gene, which encodes an anthocyanin biosynthetic enzyme. Here we show that Picotee and Star petunias carry the same short interfering RNA (siRNA)‐producing locus, consisting of two intact CHS‐A copies, PhCHS‐A1 and PhCHS‐A2, in a tandem head‐to‐tail orientation. The precursor CHS mRNAs are transcribed from the two CHS‐A copies throughout the bicolored petals, but the mature CHS mRNAs are not found in the white tissues. An analysis of small RNAs revealed the accumulation of siRNAs of 21 nucleotides that originated from the exon 2 region of both CHS‐A copies. This accumulation is closely correlated with the disappearance of the CHS mRNAs, indicating that the bicolor floral phenotype is caused by the spatially regulated post‐transcriptional silencing of both CHS‐A genes. Linkage between the tandemly arranged CHS‐A allele and the bicolor floral trait indicates that the CHS‐A allele is a necessary factor to confer the trait. We suppose that the spatially regulated production of siRNAs in Picotee and Star flowers is triggered by another putative regulatory locus, and that the silencing mechanism in this case may be different from other known mechanisms of post‐transcriptional gene silencing in plants. A sequence analysis of wild Petunia species indicated that these tandem CHS‐A genes originated from Petunia integrifolia and/or Petunia inflata, the parental species of P. hybrida, as a result of a chromosomal rearrangement rather than a gene duplication event.
Incidence, kinetics, and risk factors of Epstein–Barr virus viremia in pediatric patients after allogeneic stem cell transplantation
Authors: Bordon Victoria , Padalko Elizaveta , Benoit Yves , Dhooge Catharina , Laureys Genevieve
Published: January 2012

Bordon V, Padalko E, Benoit Y, Dhooge C, Laureys G. Incidence, kinetics, and risk factors of Epstein–Barr virus viremia in pediatric patients after allogeneic stem cell transplantation.  Pediatr Transplantation 2012: 16: 144–150. © 2012 John Wiley & Sons A/S.

Abstract:  After allogeneic hematopoietic stem‐cell transplantation (allo‐HSCT), EBV infections can be potentially dangerous and even life threatening. We evaluated the EBV viremia in 80 consecutive allo‐HSCT with quantitative EBV‐PCR every 2 weeks during the first 3 months and monthly thereafter until 1 yr after allo‐HSCT or until death. We found a significantly more frequent viremia in patients who had in vivo T‐cell depletion in which 23 out of 51 (45%) had EBV‐PCR positivity. The EBV virus load was also significantly higher in the in vivo T‐cell depleted group. Three patients developed clinical symptoms of EBV‐PTLD and were treated with monoclonal anti‐CD20 antibodies. No EBV‐ driven mortality was seen in this cohort. In our opinion EBV‐PCR monitoring is mandatory after allo‐HSCT. Most of the patients with EBV viremia had a good evolution after tapering the immune suppression, so this should be the first‐line management of pediatric patients with EBV viremia. Monoclonal anti‐CD20 antibodies should be reserved for those patients with early symptoms of EBV‐PTLD.
Effect of supplementation of vitamin E, copper and zinc on thein vitrophagocytic activity and lymphocyte proliferation index of peripartum Sahiwal (Bos indicus) cows
Authors: Dang A. K. , Prasad S. , De K. , Pal S. , Mukherjee J. , Sandeep I. V. R. , Mutoni G. , Pathan M. M. , Jamwal M. , Kapila S. , Kapila R. , Kaur H. , Dixit S. , Mohanty A. K. , Prakash B. S.
Published: January 2012

To study the effect of vitamin E (VE), copper (Cu) and zinc (Zn) supplementation on thein vitrophagocytic activity (PA) and lymphocyte proliferation response (LPR) of blood neutrophils and lymphocytes, thirty Sahiwal pregnant cows (six in each group) in their late gestation at 30 days before the expected date of calving were selected from the NDRI experimental herd and supplemented with various micronutrients from 30 days before calving to 45 days after calving. Cows were supplemented individually with VE (1000 IU/cow/day), Cu (20 ppm/cow/day) and Zn (80 ppm/cow/day) and also with a combination of VE, Cu and Zn to study cumulative effect of all micronutrients. One group without any supplementation acted as a control. Blood neutrophils and lymphocytes were isolated and studied for their PA and LPR. Supplementation of micronutrients like VE, Cu, Zn and a combination of all these nutrients significantly (p < 0.01) increased the PA of experimental cows as compared to control (unsupplemented) cows during the pre‐partum period. During post‐partum, all the micronutrients (VE, Cu, Zn and their combination) showed a significant (p < 0.01) increase in the PA of experimental cows as compared to control cows. Of all the groups, significant (p < 0.01) and maximum PA was observed in the combination group followed by Zn‐supplemented group during both the pre‐ and post‐partum period. A significant (p < 0.01) increase in LPR of B lymphocytes was observed in combination‐supplemented group during the pre‐partum period and during both the pre‐ and post‐partum period in the Cu‐supplemented group.
Comprehensive analysis of the association of SCN1A gene polymorphisms with the retention rate of carbamazepine following monotherapy for new‐onset focal seizures in the Chinese Han population
Authors: Zhou Bo‐Ting , Zhou Qiu‐Hong , Yin Ji‐Ye , Li Guo‐Liang , Xu Xiao‐Jing , Qu Jian , Liu Ding , Zhou Hong‐Hao , Liu Zhao‐Qian
Published: January 2012

The aim of the present study was to investigate whether single nucleotide polymorphisms (SNPs) in the sodium channel a subunit type 1 (SCN1A) gene affect the retention rate of carbamazepine (CBZ) used to treat seizures in Chinese Han patients with epilepsy.

In total, 448 patients were genotyped for SNPs selected in the SCN1A gene. The tag SNPs were selected using Haploview version 4.2 software (http://www.broad.mit.edu/haploview/haploview, accessed 18 Sept 2009). Monotherapy with CBZ was administered to patients with new‐onset focal seizures. In the present study, the retention rate of CBZ was defined as the percentage of patients with epilepsy who had continued with CBZ treatment in the preceding 3 months. Potential confounding variables were analysed to evaluate the risk factors for non‐retention.

When adjusted for potential confounding factors (e.g. age, sex, body mass index, seizure type etc.), the presence of the A allele of SNP rs3812718 predicted non‐retention (P = 0.015; odds ratio (OR) = 3.122; 95% confidence interval (CI) = 1.823–4.893). Beyond 12 months of treatment in those that continued with CBZ (retention cohort), analysis of covariance indicated that the maintenance dose (P = 0.025) and serum CBZ levels (P = 0.021) were significantly higher in carriers of the rs3812718 AA genotype than in those with the GG genotype.

The results of the present study indicate that the rs3812718 SNP in the SCN1A gene is significantly associated with the retention rate of CBZ monotherapy in Chinese Han patients with focal epilepsy.
Risk stratification for metastasis from cutaneous squamous cell carcinoma of the head and neck
Authors: Peat Bruce , Insull Phillip , Ayers Rebecca
Published: January 2012

Background:  The purpose of the study was to develop a system of risk stratification, based on clinical and histological factors that would aid prediction of metastasis from cutaneous squamous cell carcinoma (SCC) of the head and neck.

Method:  The method used was a retrospective case control study comparing clinical and histological parameters of 78 patients who developed metastasis with 92 patients who did not develop metastasis over a 5‐year period.

Results:  The two ‘absolute’ (highest) risk factors for development of metastatic disease are poor histological differentiation and perineural/lymphovascular infiltration. The three ‘relative’ risk factors are moderate histological differentiation, diameter ≥20 mm and Clark level 5.

Risk stratification:  High‐risk lesions have either one of the absolute risk factors or all three of the relative risk factors with a predicted incidence of metastasis of 37%. Intermediate risk lesions have two of three relative risk factors and a predicted incidence of metastasis of 5%. Low‐risk lesions have one or none of the relative risk factors and a predicted incidence of meatstasis of 0.3%.

Conclusion:  Ongoing management of patients with histo‐pathologically proven invasive SCC of the head and neck should be based upon risk stratification for metastasis.
Evaluation of iron deficiency anaemia in tertiary hospital settings: room for improvement?
Authors: Khadem G. , Scott I. A. , Klein K.
Published: January 2012

Background:  Iron deficiency anaemia (IDA) is a marker of occult blood loss from gastrointestinal (GI) lesions and requires thorough GI evaluation.

Aim:  This study aimed to determine frequency and findings of GI endoscopy in patients with IDA attending a tertiary hospital, and associations of endoscopy with patient and clinician‐related factors and results of faecal occult blood tests (FOBT).

Methods:  Retrospective audit of 621 subjects identified with definite and probable IDA (serum ferritin ≤15 ug/L and 16–50 µg/L respectively) between 1 January 2006 and 31 December 31 2008. Subjects were analysed as males >18 years and females ≥45 years of age with definite (group A, n= 180) or probable (group B, n= 353) IDA, and females <45 years of age with definite or probable IDA (group C, n= 88).

Results:  Endoscopy of any type was documented in 310 (50%) of patients with oesophagogastroduodenal endoscopy, and colonoscopy rates being significantly higher in group A patients (61% and 56% respectively) than in group B (39%, 37%) and group C (30%, 31%; P≤ 0.01 for all comparisons). Endoscopy rates ranged from 96% of patients seeing gastroenterologists to 31% of those seeing nephrologists. In patients undergoing colonoscopy, cancer and high‐risk adenomas were detected in 51 patients (20%), ranging from 27/100 (27%) of group A, 23/130 (18%) of group B and 1/27 (4%) of group C. Lesion prevalence was similar (19–24%) regardless of whether FOBT yielded positive or negative results or had not been performed.

Conclusions:  Almost one in two patients with IDA were not documented as undergoing GI endoscopy. More intense guideline promulgation, improved endoscopy access and ongoing practice audits are required to improve endoscopy rates.
Rheumatic heart disease in pregnancy: cardiac and obstetric outcomes
Authors: Sartain J. B. , Anderson N. L. , Barry J. J. , Boyd P. T. , Howat P. W.
Published: January 2012

Background:  Rheumatic heart disease (RHD) remains an important health issue for indigenous women of child‐bearing age in northern Australia. However, the influence of RHD on maternal outcomes with current clinical practice is unclear.

Aims:  To determine maternal cardiac complications and obstetric outcomes in patients with RHD.

Methods:  Retrospective case note analysis of women with RHD who received obstetric care between July 1999 and May 2010 at Cairns Base Hospital in north Queensland. Outcome measures were obstetric interventions and outcomes, cardiac interventions and complications, stratified according to a cardiac risk score (CRS).

Results:  Ninety‐five confinements occurred in 54 patients, of whom 52 were Indigenous Australians. There were no maternal or neonatal deaths. With a CRS of 0, cardiac complications occurred in 0 of 70 confinements; with a CRS of 1, complications occurred in 5 of 17 confinements (29%); with a CRS of >1, complications occurred in 2 of 4 confinements (50%). Another four patients were first diagnosed with RHD after developing acute pulmonary oedema during the peripartum period.

Conclusions:  RHD has a major impact on maternal cardiac outcomes. However, with current management practices, maternal and fetal mortality are low, and the incidence of complications is predictable based on known risk factors.
Effects of methylnaltrexone in patients with narcotic bowel syndrome: a pilot observational study
Authors: Gibson P. R. , Morrison G.
Published: January 2012

Background:  Narcotic bowel syndrome (NBS) describes disabling chronic severe abdominal pain that worsens despite continuing or escalating doses of opiates. Therapy is very limited.

Aim:  To examine effects of blocking peripheral µ‐opioid receptors on the symptomatology of patients with NBS and its safety.

Methods:  An open‐label observational study was performed in four women with NBS. After a 2‐week run‐in period, patients were treated for 12 weeks with 8–12 mg methylnaltrexone bromide subcutaneously every other day, increasing to daily if there was poor response. Patient and physician assessment was documented, and patients completed an eight‐symptom visual analogue scale weekly and the Functional Assessment of Chronic Illnesses Therapy‐Fatigue questionnaire for fatigue. Patients were observed for 4 weeks following withdrawal of the drug.

Results:  One patient was unable to tolerate the study medication because of worsening pain after injection, and withdrew. Two showed clear benefit with reduction of symptoms overall, pain, bloating, distension, nausea and tiredness, with improved satisfaction and consistency of bowel actions and fatigue scores. Both reduced analgesic usage. The third had improved ileostomy output and had no episodes of severe bloating, but pain scores remained high. All three worsened after drug withdrawal and requested retreatment. Three experienced abdominal pains of moderate severity for 30–60 min consistently within 5 min of each injection. No other adverse events were experienced.

Conclusions:  Methylnaltrexone has a positive impact on symptoms in women with NBS, although treatment does induce transient pain following its administration. Larger studies are required to examine its efficacy and longer term safety in this patient group.