bluuebunny/crossref_metadata_2025 huggingface dataset:
An O-Acetylserine(thiol)lyase Homolog with l-Cysteine Desulfhydrase Activity Regulates Cysteine Homeostasis in Arabidopsis
Authors: Aݩlvarez Consolacioݩn , Calo Leticia , Romero Luis C. , Garciݩa Irene , Gotor Cecilia
Published: December 2009

Cysteine (Cys) occupies a central position in plant metabolism due to its biochemical functions. Arabidopsis (Arabidopsis thaliana) cells contain different O-acetylserine(thiol)lyase (OASTL) enzymes that catalyze the biosynthesis of Cys. Because they are localized in the cytosol, plastids, and mitochondria, this results in multiple subcellular Cys pools. Much progress has been made on the most abundant OASTL enzymes; however, information on the less abundant OASTL-like proteins has been scarce. To unequivocally establish the enzymatic reaction catalyzed by the minor cytosolic OASTL isoform CS-LIKE (for Cys synthase-like; At5g28030), we expressed this enzyme in bacteria and characterized the purified recombinant protein. Our results demonstrate that CS-LIKE catalyzes the desulfuration of l-Cys to sulfide plus ammonia and pyruvate. Thus, CS-LIKE is a novel l-Cys desulfhydrase (EC 4.4.1.1), and we propose to designate it DES1. The impact and functionality of DES1 in Cys metabolism was revealed by the phenotype of the T-DNA insertion mutants des1-1 and des1-2. Mutation of the DES1 gene leads to premature leaf senescence, as demonstrated by the increased expression of senescence-associated genes and transcription factors. Also, the absence of DES1 significantly reduces the total Cys desulfuration activity in leaves, and there is a concomitant increase in the total Cys content. As a consequence, the expression levels of sulfur-responsive genes are deregulated, and the mutant plants show enhanced antioxidant defenses and tolerance to conditions that promote oxidative stress. Our results suggest that DES1 from Arabidopsis is an l-Cys desulfhydrase involved in maintaining Cys homeostasis, mainly at late developmental stages or under environmental perturbations.
Arabidopsis Deadenylases AtCAF1a and AtCAF1b Play Overlapping and Distinct Roles in Mediating Environmental Stress Responses
Authors: Walley Justin W. , Kelley Dior R. , Nestorova Gergana , Hirschberg David L. , Dehesh Katayoon
Published: December 2009

To maintain homeostasis in an ever-changing environment organisms have evolved mechanisms to reprogram gene expression. One central mechanism regulating gene expression is messenger RNA (mRNA) degradation, which is initiated by poly(A) tail shortening (deadenylation). The carbon catabolite repressor 4-CCR4 associated factor1 (CCR4-CAF1) complex is the major enzyme complex that catalyzes mRNA deadenylation and is conserved among eukaryotes. However, the components and functions of this global regulatory complex have not been well characterized in plants. Here we investigate the CAF1 family in Arabidopsis (Arabidopsis thaliana). We identify 11 AtCAF1 homologs and show that a subset of these genes are responsive to mechanical wounding, among them are AtCAF1a and AtCAF1b whose expression levels are rapidly and transiently induced by wounding. The differential expression profiles of the various AtCAF1s suggest that not all AtCAF1 genes are involved in stress-responsive regulation of transcript levels. Comparison of misexpressed genes identified via transcript profiling of Atcaf1a and Atcaf1b mutants at different time points before and after wounding suggests that AtCAF1a and AtCAF1b target shared and unique transcripts for deadenylation with temporal specificity. Consistent with the AtPI4Kγ3 transcript exhibiting the largest increase in abundance in Atcaf1b, AtCAF1b targets AtPI4Kγ3 mRNA for deadenylation. Stress-tolerance assays demonstrate that AtCAF1a and AtCAF1b are involved in mediating abiotic stress responses. However, AtCAF1a and AtCAF1b are not functionally redundant in all cases, nor are they essential for all environmental stresses. These findings demonstrate that these closely related proteins exhibit overlapping and distinct roles with respect to mRNA deadenylation and mediation of stress responses.
Functional constraints on nest characteristics of pebble mounds of breeding male hornyhead chub Nocomis biguttatus
Authors: Wisenden B. D. , Unruh A. , Morantes A. , Bury S. , Curry B. , Driscoll R. , Hussein M. , Markegard S.
Published: December 2009

Breeding male hornyhead chub Nocomis biguttatus constructed nests in areas with relatively high but less than maximum flow rate and greater than average water depth. Nests comprised c. 3000 pebbles for a total mass of 11 kg. Males selected pebbles of smaller diameter but higher density than pebbles in the immediate vicinity. Thus, nests balanced the risk of mound erosion and energetic cost of nest construction with the benefits of protection from egg predators and a stable internal flow rate for oxygenation. These data help establish environmental management goals for the conservation of N. biguttatus and the lotic ecosystems dependent upon them.
Ontogeny of the cranial musculature in Corydoras aeneus Callichthyidae, Siluriformes
Authors: Huysentruyt F. , Brunain M. , Adriaens D.
Published: December 2009

A complete study of the early ontogeny of the cranial muscles of Corydoras aeneus (Callichthyidae) was undertaken and results were compared with those for the loricariid Ancistrus cf. triradiatus. This comparison reveals a high degree of similarity in the ontogeny of both species' cranial muscles. Both species lack a musculus protractor hyoidei, and the musculus intermandibularis posterior is divided into two different parts that have partly obtained a novel function (serving the lower lip) in A. cf. triradiatus. A similar increase in muscular complexity in this species is found in the dorsal constrictor of the hyoid muscle plate. This constrictor gives rise to the same muscles in both C. aeneus and A. cf. triradiatus, but in A. cf. triradiatus the musculus levator operculi later hypertrophies. In C. aeneus the musculus extensor tentaculi forms a single muscle diverging posteriorly, whereas in A. cf. triradiatus the musculus extensor tentaculi differentiates into two separate bundles. Also, a loricariid neoformation is present called the musculus levator tentaculi.
Swimming performance and associated ionic disturbance of juvenile pink salmon Oncorhynchus gorbuscha determined using different acceleration profiles
Authors: Nendick L. , Grant A. , Gardner M. , Sackville M. , Brauner C. J. , Farrell A. P.
Published: December 2009

Swimming performance was assessed in juvenile pink salmon Oncorhynchus gorbuscha (body mass <5·0 g) using five different protocols: four constant acceleration tests each with a different acceleration profile (rates of 0·005, 0·011, 0·021 and 0·053 cm s−2) and a repeated ramped‐critical swimming speed test. Regardless of the swim protocol, the final swimming speeds did not differ significantly (P > 0·05) among swim tests and ranged from 4·54 to 5·20 body lengths s−1. This result supports the hypothesis that at an early life stage, O. gorbuscha display the same fatigue speeds independent of the swimming test utilized. Whole body and plasma [Na+] and [Cl−] measured at the conclusion of these tests were significantly elevated when compared with control values (P < 0·05) and appear to be predominantly associated with dehydration rather than net ion gain. Given this finding for a small salmonid, estimates of swim performance can be accurately measured with acceleration tests lasting <10 min, allowing a more rapid processing than is possible with a longer critical swim speed test.
Size and age estimates at sexual maturity for the little skate Leucoraja erinacea from the western Gulf of Maine, U.S.A.
Authors: Cicia A. M. , Driggers W. B. , Ingram G. W. , Kneebone J. , Tsang P. C. W. , Koester D. M. , Sulikowski J. A.
Published: December 2009

Size and age estimates at sexual maturity were determined for 162 male and 273 female little skates Leucoraja erinacea collected from the western Gulf of Maine. Maturity ogives suggest that 50% maturity in females occurs at age 9·5 years and 480 mm total length (LT), whereas 50% maturity in males occurs at a slightly younger age of 7·7 years and smaller size of 460 mm LT. Age estimates were made from 389 L. erinacea ranging in size from 93 to 570 mm LT. The index of average per cent error and age‐bias plots indicated that the ageing methods were precise and non‐biased. Additionally, annual periodicity of band formation was validated with oxytetracycline in eight individuals (three males and five females) ranging in age from 3 to 12 years. In conclusion, results from this study indicate that L. erinacea exhibits characteristics that make other elasmobranch populations highly susceptible to overexploitation.
Specialized morphology for a generalist diet: evidence for Liem's Paradox in a cichlid fish
Authors: Binning S. A. , Chapman L. J. , Cosandey‐Godin A.
Published: December 2009

The stable isotope ratio and seasonal changes in diet of Alluaud's haplo Astatoreochromis alluaudi, a cichlid fish with massive pharyngeal jaws well known for its ability to process hard‐bodied prey, are described. The diet of A. alluaudi was quantified in Lake Saka, Uganda, over a period of 30 months. Variation in physico‐chemical variables (mean monthly rainfall, water temperature, turbidity and dissolved oxygen), as well as potential competitor density and food abundance, was measured throughout the second half of the study (14 months). Stomach contents and isotope analysis revealed a diet comprised mainly of fishes and insects, with a low contribution of molluscs (0–33%) in any given month. No correlation was detected between diet and either macroinvertebrate abundance or competitor abundance. The running average rainfall was positively related to the percentage of fish consumed per month. Although A. alluaudi exhibits an apparent molluscivorous trophic morphology in Lake Saka, molluscs did not appear to compose a major portion of its diet. Gradients of rainfall seemed to be the most important environmental predictor of diet choice in Lake Saka. These results are discussed with reference to Liem's Paradox that apparently morphologically specialized fishes often function as generalist feeders in the wild.
Age and growth of the gulf toadfishOpsanus betabased on otolith increment analysis
Authors: Malca E. , Barimo J. F. , Serafy J. E. , Walsh P. J.
Published: December 2009

In the present study, sagittal otoliths of confirmed male and female specimens of the gulf toadfishOpsanus betathat were collected monthly over the course of a year from Biscayne Bay, Florida, U.S.A. were analysed. The timing and frequency ofO. betaspawning seasons are reported by examination of the gonado‐somatic index. The estimated ages of males and females ranged from < 1 year to 6 and 5 years, respectively. Strong sexual dimorphism in growth was apparent with von Bertalanffy parameter estimates for males ofL∞= 393·8 mm,K= 0·30,t0= 0·36 and females ofL∞= 201·1 mm,K= 0·79,t0= 0·47. Comparison with previously published growth trajectories of the more northerly distributed conspecificOpsanus taushowed thatO. betamales had a higher growth rate. FemaleO. betaandO. taugrowth trajectories appear similar, with an indication that the former becomes asymptotic at least a year before the latter. Results are discussed in the context of temperature regimes, reproductive energy allocation and waste urea excretion in the two species.
Severely degraded dunes of the southern Kalahari: local extinction, persistence and natural re‐establishment of plants
Authors: Rutherford Michael Charles , Powrie Leslie Ward
Published: December 2009

This study aimed to quantify and understand the impact of severe land degradation on plant attributes and diversity on dunes of the southern Kalahari. Heavy grazing pressure in particular resulted in a significant decline of canopy cover and species number in annual and perennial life forms; forb and graminoid growth forms; erect and prostrate habits; and leafy stem, tussock and stoloniferous architectures. However, no significant change was found in shrub and tree forms which persisted without apparent new recruitment. Under these conditions, species diversity dropped sharply and a number of species, mainly graminoids, became apparently locally extinct. The perennial shrub, Crotalaria cf. spartioides, showed the converse with a high frequency of establishing seedlings on the degraded dunes. Changes in relative dominance show that the extreme treatment favours perennial over annual, woody over graminoid and forb, erect over prostrate and leafy stem over stoloniferous and tussock. Some of these results and certain species and soil responses differ from those reported from grazing studies elsewhere, and are possibly no longer directly related to the impact of the primary grazing pressure but to the secondary effect of subsequent instability of the dunes.
Effect of intra‐operative pressure support vs pressure controlled ventilation on oxygenation and lung function in moderately obese adults*
Authors: Zoremba M. , Kalmus G. , Dette F. , Kuhn C. , Wulf H.
Published: December 2009

Obesity impairs peri‐operative lung function. To evaluate the impact of pressure support ventilation vs pressure controlled ventilation in moderately obese adults upon early postoperative lung function, we randomly assigned 68 moderately obese patients (body mass index 25–35 kg.m−2) undergoing minor surgery to receive intra‐operative ventilation either with pressure support or pressure controlled ventilation. We performed intra‐operative blood gas analysis and measured pulse oximetry saturation, spirometry values at pre‐operative assessment (baseline) and at 10 min, 30 min, 2 h and 24 h after extubation. The intra‐operative oxygenation index (arterial partial pressure of oxygen/fraction of inspired oxygen) in the pressure support ventilation group was significantly improved over time (p < 0.0001). Postoperatively, the pressure support ventilation group also had better lung function and oxygenation values than did the pressure controlled ventilation group (p < 0.005). We conclude that pressure support ventilation better maintains lung function than pressure controlled ventilation in moderately overweight patients scheduled for minor surgery.
Impact of dexamethasone responsiveness on long term outcome in patients with newly diagnosed multiple myeloma
Authors: Sinha Shirshendu , Vincent Rajkumar S. , Lacy Martha Q. , Hayman Suzanne R. , Buadi Francis K. , Dispenzieri Angela , Dingli David , Kyle Robert A. , Gertz Morie A. , Kumar Shaji
Published: December 2009

Dexamethasone (Dex), alone or in combination, is commonly used for treating multiple myeloma. Dex as single agent for initial therapy of myeloma results in overall response rates of 50–60%. It is unclear whether steroid responsiveness reflects any biological characteristic that impacts long‐term outcome. We studied a cohort of 182 patients with newly diagnosed myeloma seen between March 1998 and June 2007, initially treated with single‐agent Dex for at least 4 weeks. The median age at diagnosis was 63 years (range, 39–81) and the median estimated survival was 55 months. At a median duration of therapy of 15 weeks, 91 (50%) patients had a partial response or better, 80 (44%) had less than partial response and the remaining (6%) patients were not evaluable. The median overall survival from diagnosis for the responders was 75 months compared to 71 months for remaining patients, P = 0·6.There was no correlation between baseline disease characteristics and Dex responsiveness. While overall survival was longer for the 130 (70%) patients who proceeded to an autologous stem cell transplant, no correlation was found between survival and Dex responsiveness among either group. Among this cohort of patients with myeloma, failure to respond to single agent steroid did not have an adverse impact on eventual outcome.
The development and persistence of alternative ecosystem states in a large, shallow lake
Authors: WATERS MATTHEW N. , PIEHLER MICHAEL F. , SMOAK JOSEPH M. , MARTENS CHRISTOPHER S.
Published: December 2009

1. Palaeolimnological data were used to investigate drivers of the community of primary producers in Lake Mattamuskeet, North Carolina, U.S.A. This is a large, shallow lake with two basins currently dominated by phytoplankton and macrophytes. The two basins were divided in 1940 by the building of a roadway across the lake, which also corresponded with the divergence in their ecosystem state.

2. Photosynthetic pigments, organic matter and nutrients (P, N, C, S) were analysed in sediment cores from each basin to reconstruct the primary producer community over the past c. 100 years. We sought to answer two questions. First, what changes to the ecosystem resulting from the building of the roadway caused the development of different primary producer communities in the two basins? Second, why have the alternative ecosystem states persisted despite a variety of human perturbations since 1940?

3. K‐means cluster analysis and principal component analysis were applied to identify three sediment types based on photosynthetic pigment data: sediments indicating low productivity (low pigment concentrations), sediments associated with macrophytes (chlorophyll a and b) and with phytoplankton (alloxanthin and aphanizophyll). In addition, other palaeolimnological proxies measured, such as loss on ignition, total phosphorus, total organic carbon/total nitrogen and other nutrients, were different in post‐1940 sediments within the two basins.

4. These differences suggest characteristics, such as nutrient cycling, water depth and other physical changes resulting from roadway construction, combined to establish and maintain the differing communities of primary producers in the two basins. Furthermore, Fe/S dynamics and waterfowl herbivory probably contributed to the development of the two ecosystem states.
Selection by sheep and goats for perennial ryegrass and white clover offered over a range of sward height contrasts
Authors: Concha M. A. , Nicol A. M.
Published: December 2009

The selection by sheep (six Coopworth ewe hoggets, 44·3 ± 4·6 kg live weight) and goats (six Saanen/Anglo‐Nubian yearling males, 38·1 ± 3·8 kg live weight) for perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) and for sward height was measured in two experiments involving paired turves. Pairs of turves with herbage of differing height and of either the same or different plant species were offered. One sward (fixed height species, FHS) was always offered at 130 mm and the other (variable height species, VHS) at 130, 90 or 50 mm. Turves (450 mm × 220 mm) were cut to a soil depth of 100–150 mm from areas of perennial ryegrass and white clover regrown to the desired height after previously being cut to 30 mm. Each turf in a pair was weighed (±1 g) before and after grazing by penned animals maintained on a barley‐based pelleted diet. The number of prehending bites taken from each turf was recorded over a grazing period (128 ± 12 s). Bite mass, bite rate and intake rate were calculated.

As the sward height of the VHS turf declined, an increasing proportion of the diet was selected from the 130 mm turf. When averaged over all height contrasts, both animal species selected a higher proportion (0·776 ± 0·026) of their diet from 130‐mm white clover than from 130‐mm perennial ryegrass (0·591 ± 0·018) turves. On average, goats selected a higher proportion (0·721 ± 0·022) of their dry‐matter (DM) intake from the 130‐mm turf than sheep (0·646 ± 0·019), but the effect was not consistent. In contrasts with perennial ryegrass as the VHS (and both perennial ryegrass and white clover as FHS), the proportion of the diet selected from the 130‐mm turf was very similar for both animal species. However, with white clover as the VHS (and both perennial ryegrass and white clover as FHS), goats selected a higher proportion of their intake from the 130‐mm turf to the extent that in the 130‐mm perennial ryegrass/50‐mm white clover contrast sheep showed as strong selection for 50‐mm white clover as goats did for 130‐mm perennial ryegrass. This lesser selection of goats for white clover as its height in a sward declines is likely to contribute to the higher white clover content observed in swards grazed by goats.

Bite mass was greater on white clover (246 ± 5 mg DM bite–1) than on perennial ryegrass (173 ± 5 mg DM bite–1) and was greater for goats (255 ± 6 mg DM bite–1) than for sheep (195 ± 5 mg DM bite–1). Bite rate was greater on perennial ryegrass (45·9 ± 1·0 bites min–1) than on white clover (39·9 ± 1·0 bites min–1) and was greater for sheep (45·5 ± 1·1 bites min–1) than for goats (42·5 ± 1·1 bites min–1). Apparent intake rate by both sheep and goats was lower (mean, 5·0 ± 0·29 g DM min–1) on 130 mm perennial ryegrass/white clover than on 130 mm perennial ryegrass/perennial ryegrass (7·0 ± 0·27 g DM min–1), but was higher (9·62 ± 0·29 g DM min–1) on 130‐mm white clover/perennial ryegrass than on 130‐mm white clover/white clover (8·2 ± 0·29 g DM min–1) combinations.
Calcium‐binding proteins in skeletal muscles of the mdx mice: potential role in the pathogenesis of Duchenne muscular dystrophy
Authors: Pertille Adriana , De Carvalho Candida Luiza Tonizza , Matsumura Cintia Yuri , Neto Humberto Santo , Marques Maria Julia
Published: December 2009

Duchenne muscular dystrophy is one of the most common hereditary diseases. Abnormal ion handling renders dystrophic muscle fibers more susceptible to necrosis and a rise in intracellular calcium is an important initiating event in dystrophic muscle pathogenesis. In the mdx mice, muscles are affected with different intensities and some muscles are spared. We investigated the levels of the calcium‐binding proteins calsequestrin and calmodulin in the non‐spared axial (sternomastoid and diaphragm), limb (tibialis anterior and soleus), cardiac and in the spared extraocular muscles (EOM) of control and mdx mice. Immunoblotting analysis showed a significant increase of the proteins in the spared mdx EOM and a significant decrease in the most affected diaphragm. Both proteins were comparable to the cardiac muscle controls. In limb and sternomastoid muscles, calmodulin and calsequestrin were affected differently. These results suggest that differential levels of the calcium‐handling proteins may be involved in the pathogenesis of myonecrosis in mdx muscles. Understanding the signaling mechanisms involving Ca2+‐calmodulin activation and calsequestrin expression may be a valuable way to develop new therapeutic approaches to the dystrophinopaties.
Areas of endemism in the Antarctic – a case study of the benthic hydrozoan genusOswaldella(Cnidaria, Kirchenpaueriidae)
Authors: Marques Antonio C. , Peña Cantero Alvaro L.
Published: December 2009

Aim The aim of this study is to investigate areas of endemism within the distribution ofOswaldellaspecies in the Southern Ocean, thereby testing previous hypotheses and proposing alternative scenarios for Antarctic evolution.

Location Southern Ocean, Antarctic and sub‐Antarctic waters of southern South America.

Methods We prepared a database for the 31 currently known species of the Antarctic genusOswaldella, which includes geographical locations gathered from published taxonomic studies as well as materials from museums and expeditions. A parsimony analysis of endemicity (PAE) was used to test hypotheses of distribution patterns.

Results Four areas of endemism are hypothesized: southern South America, two high Antarctic areas (eastern and western) and a larger area, mainly in western Antarctica at lower latitudes and including insular areas (but not the Balleny Islands).

Main conclusions The results support, in part, previous hypotheses for the Southern Ocean region, while providing more detailed resolution. The areas of endemism may reflect both historical and ecological processes that influenced the Antarctic biota. The Magellanic area reflects the well‐known affinities of the Antarctic biota with that of South America and may be a consequence of dispersal through deeper (and colder) waters, followed by speciation. The second area, the largest one, encompasses most of the insular faunas and may also be associated with deeper waters formed since 43 Ma. The third area may be explained by the development of seaways in the circum‐Antarctic region beginning 50 Ma. Finally, the fourth zone, with a very poor fauna, coincides with the opening of the Tasman Strait and the formation of the Australo‐Antarctic Gulf, associated with a minor wind‐driven current.
Modelling the responses of Andean and Amazonian plant species to climate change: the effects of georeferencing errors and the importance of data filtering
Authors: Feeley Kenneth J. , Silman Miles R.
Published: December 2009

Aim  Species distribution models are a potentially powerful tool for predicting the effects of global change on species distributions and the resulting extinction risks. Distribution models rely on relationships between species occurrences and climate and may thus be highly sensitive to georeferencing errors in collection records. Most errors will not be caught using standard data filters. Here we assess the impacts of georeferencing errors and the importance of improved data filtering for estimates of the elevational distributions, habitat areas and predicted relative extinction risks due to climate change of nearly 1000 Neotropical plant species.

Location  The Amazon basin and tropical Andes, South America.

Methods  We model the elevational distributions, or ‘envelopes’, of 932 Amazonian and Andean plant species from 35 families after performing standard data filtering, and again using only data that have passed through an additional layer of data filtering. We test for agreement in the elevations recorded with the collection and the elevation inferred from a digital elevation model (DEM) at the collection coordinates. From each dataset we estimate species range areas and extinction risks due to the changes in habitat area caused by a 4.5 °C increase in temperature.

Results  Amazonian and Andean plant species have a median elevational range of 717 m. Using only standard data filters inflates range limits by a median of 433 m (55%). This is equivalent to overestimating the temperature tolerances of species by over 3 °C – only slightly less than the entire regional temperature change predicted over the next 50–100 years. Georeferencing errors tend to cause overestimates in the amount of climatically suitable habitat available to species and underestimates in species extinction risks due to global warming. Georeferencing error artefacts are sometimes so great that accurately predicting whether species habitat areas will decrease or increase under global warming is impossible. The drawback of additional data filtering is large decreases in the number of species modelled, with Andean species being disproportionately eliminated.

Main conclusions  Even with rigorous data filters, distribution models will mischaracterize the climatic conditions under which species occur due to errors in the collection data. These errors affect predictions of the effects of climate change on species ranges and biodiversity, and are particularly problematic in mountainous areas. Additional data filtering reduces georeferencing errors but eliminates many species due to a lack of sufficient ‘clean’ data, thereby limiting our ability to predict the effects of climate change in many ecologically important and sensitive regions such as the Andes Biodiversity Hotspot.
Relation between renal function, presentation, use of therapies and in‐hospital complications in acute coronary syndrome: data from the SWEDEHEART register
Authors: Szummer K. , Lundman P. , Jacobson S. H. , Schön S. , Lindbäck J. , Stenestrand U. , Wallentin L. , Jernberg T. ,   for SWEDEHEART
Published: December 2009

Abstract.  Szummer K, Lundman P, Jacobson SH, Schön S, Lindbäck J, Stenestrand U, Wallentin L, Jernberg T, for SWEDEHEART. (Karolinska Institute, Karolinska University Hospital, Stockholm; Karolinska Institute, Danderyd Hospital, Danderyd; Ryhov County Hospital, Jönköping; University Hospital, Uppsala and University Hospital, Linköping; Sweden) Relation between renal function, presentation, use of therapies and in‐hospital complications in acute coronary syndrome: data from the SWEDEHEART register. J Intern Med 2010; 268:40–49.

Objective.  To examine clinical characteristics, presenting symptoms, use of therapy and in‐hospital complications in relation to renal function in patients with myocardial infarction (MI).

Design.  Observational study.

Setting.  Nationwide coronary care unit registry between 2003–2006 in Sweden.

Subjects.  Consecutive MI patients with available creatinine (n = 57 477).

Results.  Glomerular filtration rate was estimated with the Modification of Diet in Renal Disease Study formula. With declining renal function patients were older, had more co‐morbidities and more often used cardio‐protective medication on admission. Compared to patients with normal renal function, fewer with renal failure presented with chest pain (90% vs. 67%, P < 0.001), Killip I (89% vs. 58%, P < 0.001) and ST‐elevation myocardial infarction (STEMI) (41% vs. 22%, P < 0.001). In a logistic regression model lower renal function was independently associated with a less frequent use of anticoagulant and revascularization in non‐ST‐elevation MI. The likelihood of receiving reperfusion therapy for STEMI was similar in patients with normal‐to‐moderate renal dysfunction, but decreased in severe renal dysfunction or renal failure. Reperfusion therapy shifted from primary percutaneous coronary intervention in 71% of patients with normal renal function to fibrinolysis in 58% of those with renal failure. Renal function was associated with a higher rate of complications and an exponential increase in in‐hospital mortality from 2.5% to 24.2% across the renal function groups.

Conclusion.  Renal insufficiency influences the presentation and reduces the likelihood of receiving treatment according to current guidelines. Short‐term prognosis remains poor.
Current and future recanalization strategies for acute ischemic stroke
Authors: Alexandrov A. V.
Published: December 2009

Abstract. Alexandrov AV (University of Alabama Hospital, Birmingham, AL, USA). Current and future recanalization strategies for acute ischemic stroke (Review).J Intern Med2010;267:209–219.

In a quest for stroke treatment, reperfusion proved to be the first key to the puzzle. Systemic tissue plasminogen activator (tPA), the first and currently the only approved treatment, is also the fastest way to initiate thrombolyis for acute ischemic stroke. tPA works by induction of mostly partial recanalization since stroke patients often have large thrombus burden. Thus, early augmentation of fibrinolysis and multi‐modal approach to improve recanalization are desirable. This review focuses on the following strategies available to clinicians now or being tested in clinical trials: (a) faster initiation of tPA infusion; (b) sonothrombolysis; (c) intra‐arterial revascularization, bridging intravenous and intra‐arterial thrombolysis, mechanical thrombectomy and aspiration; and (d) novel experimental approaches. Despite these technological advances, no single strategy was yet proven to be a ‘silver bullet’ solution to reverse acute ischemic stroke. Better outcomes are expected with faster treatment leading to early, at times just partial flow improvement rather than achieving complete recanalization with lengthy procedures. Arterial re‐occlusion can occur with any of these approaches, and it remains a challenge since it leads to poor outcomes and no clinical trial data are available yet to determine safe strategies to prevent or reverse re‐occlusion.
Properties and microstructure of the (Fe, Ni)–Cu–(P, Si, B) melt‐spun alloys
Authors: ZIEWIEC K. , BRYŁA K. , BŁACHOWSKI A. , RUEBENBAUER K. , PRUSIK K. , KĄC S. , KOZIEŁ T.
Published: December 2009

The work presents the microstructure characterization of the new (Fe, Ni)–Cu–(P, Si, B) melt‐spun glass forming alloys investigated by means of transmission electron microscope. The results are compared with the data obtained by other complementary methods such as XRD and Mössbauer spectroscopy. The phases occurring during the crystallization of the glassy matrix are identified and characterized in terms of a long‐range order and a short‐range order. The thermal stability of the alloy is characterized by differential scanning calorimetry. The study describes the mechanical and magnetic properties of the new alloys at room temperature as well as characteristics resulting from heating the as‐cast melt‐spun alloy at elevated temperatures. The changes of the properties of the alloy at elevated temperatures are correlated with the microstructural changes.
Analysis of damaged region of carbon implanted alumina
Authors: GONZÁLEZ M. , ROMÁN R. , GONZÁLEZ‐CASABLANCA J. , GOMEZ A. , HOLE D.
Published: December 2009

Implantation was performed on surface‐polished and thermal‐treated alumina discs with 75 keV monocharged carbon ions at doses of 1 × 1017 and 5 × 1017 ions cm−2. The alumina targets were kept at room temperature. The structural modifications induced during ion irradiation were studied by the scanning and scanning transmission electron microscopes. Alumina is readily amorphized at room temperature with carbon ions. The width of the ion‐beam induced disordered area increases with ion dose. As it was established by selected area electron diffraction and electron energy loss spectra, low implanted specimens still show subsurface crystalline areas whose diffraction patterns could be assigned to a deformed structure of alumina. This deformed belt is shown beneath the amorphous region on highly implanted samples. Electron energy loss spectroscopy allows to follow the carbon line profile from surface into the bulk material, pointing the maximum concentration of implanted ion on the lower half of the amorphous region. Structural changes of Al2O3 caused by carbon ion irradiation were corroborated with X‐ray photoelectron spectroscopy. The X‐ray photoelectron spectroscopy experiments showed that the oxygen concentration in the vicinity of the implanted alumina surface was reduced suggesting that this element was selectively sputtered by carbon irradiation. As a function of depth, peaks referring to Al–O bindings diminish while contributions of reduced aluminium and metal carbides were found, reaching the corresponding maxima at a depth of about 130 nm.
An improved strip FRAP method for estimating diffusion coefficients: correcting for the degree of photobleaching
Authors: YANG J. , KÖHLER K. , DAVIS D. M. , BURROUGHS N. J.
Published: December 2009

Fluorescence recovery after photobleaching is a widely established method for the estimation of diffusion coefficients, strip bleaching with an associated recovery curve analysis being one of the simplest techniques. However, its implementation requires near 100% bleaching in the region of interest with negligible fluorescence loss outside, both constraints being hard to achieve concomitantly for fast diffusing molecules. We demonstrate that when these requirements are not met there is an error in the estimation of the diffusion coefficient D, either an under‐ or overestimation depending on which assumption is violated the most. We propose a simple modification to the recovery curve analysis incorporating the concept of the relative bleached mass m giving a revised recovery time parametrization τ=m2w2/4πD for a strip of width w. This modified model removes the requirement of 100% bleaching in the region of interest and allows for limited diffusion of the fluorophore during bleaching. We validate our method by estimating the (volume) diffusion coefficient of FITC‐labelled IgG in 60% glycerol solution, D= 4.09 ± 0.21 μm2 s−1, and the (surface) diffusion coefficient of a green‐fluorescent protein‐tagged class I MHC protein expressed at the surface of a human B cell line, D= 0.32 ± 0.03 μm2 s−1 for a population of cells.
Ecological, morphological and genetic divergence of sympatric North Atlantic killer whale populations
Authors: FOOTE ANDREW D. , NEWTON JASON , PIERTNEY STUART B. , WILLERSLEV ESKE , GILBERT M. THOMAS P.
Published: December 2009

Ecological divergence has a central role in speciation and is therefore an important source of biodiversity. Studying the micro‐evolutionary processes of ecological diversification at its early stages provides an opportunity for investigating the causative mechanisms and ecological conditions promoting divergence. Here we use morphological traits, nitrogen stable isotope ratios and tooth wear to characterize two disparate types of North Atlantic killer whale. We find a highly specialist type, which reaches up to 8.5 m in length and a generalist type which reaches up to 6.6 m in length. There is a single fixed genetic difference in the mtDNA control region between these types, indicating integrity of groupings and a shallow divergence. Phylogenetic analysis indicates this divergence is independent of similar ecological divergences in the Pacific and Antarctic. Niche‐width in the generalist type is more strongly influenced by between‐individual variation rather than within‐individual variation in the composition of the diet. This first step to divergent specialization on different ecological resources provides a rare example of the ecological conditions at the early stages of adaptive radiation.
Asymmetric cross‐regulation between the nitrate‐responsive NarX–NarL and NarQ–NarP two‐component regulatory systems from Escherichia coli K‐12
Authors: Noriega Chris E. , Lin Hsia‐Yin , Chen Li‐Ling , Williams Stanly B. , Stewart Valley
Published: December 2009

The NarX–NarL and NarQ–NarP sensor–response regulator pairs control Escherichia coli gene expression in response to nitrate and nitrite. Previous analysis suggests that the Nar two‐component systems form a cross‐regulation network in vivo. Here we report on the kinetics of phosphoryl transfer between different sensor–regulator combinations in vitro. NarX exhibited a noticeable kinetic preference for NarL over NarP, whereas NarQ exhibited a relatively slight kinetic preference for NarL. These findings were substantiated in reactions containing one sensor and both response regulators, or with two sensors and a single response regulator. We isolated 21 NarX mutants with missense substitutions in the cytoplasmic central and transmitter modules. These confer phenotypes that reflect defects in phospho‐NarL dephosphorylation. Five of these mutants, all with substitutions in the transmitter DHp domain, also exhibited NarP‐blind phenotypes. Phosphoryl transfer assays in vitro confirmed that these NarX mutants have defects in catalysing NarP phosphorylation. By contrast, the corresponding NarQ mutants conferred phenotypes indicating comparable interactions with both NarP and NarL. Our overall results reveal asymmetry in the Nar cross‐regulation network, such that NarQ interacts similarly with both response regulators, whereas NarX interacts preferentially with NarL.
Related cord blood banking for haematopoietic stem cell transplantation
Authors: Screnci M. , Murgi E. , Carmini D. , Piro L. , Cinelli N. , Laurenti L. , Iori A. P. , Simone F. , Massari S. , Girelli G.
Published: December 2009

The aims of this single centre study were to assess the feasibility of related cord blood collecting, the appropriateness of storage and the final suitability for transplantation. Since September 1994, 63 families were enrolled in this study. Families were eligible if they were caring for a patient with a disorder treatable by haematopoietic stem cell transplantation and were experiencing a pregnancy. A total of 72 cord blood units were collected and stored for 64 patients (both siblings and parents). We focussed on human leucocyte antigen (HLA) compatibility and cell content as critical requirements to unit's suitability for transplantation. HLA‐typing was carried out for 34 donor–recipient couples and most units (72%) mismatched with the related patients. About 60% of collections had a minimum cell dose considered acceptable for transplantation. Only 21% of units had both compatibility degree and cell content suitable for transplantation. When applicable, information on the compatibility degree between the foetus and the patient should be obtained during pregnancy. Appropriateness of related cord blood banking for parents should be further investigated and cost‐effective guidelines policies should be provided. Finally, as banking of related cord blood units is an important resource then, this public service should be supported and enhanced.
Blood concentrations of midazolam in status epilepticus using an appropriate condition of HPLC
Authors: Iwasaki Toshiyuki , Nonoda Yutaka , Ishii Masahiro , Osawa Makiko
Published: December 2009

Background:  The aim of the present study was to determine an index to evaluate the efficacy and safety of midazolam (MDZ) to treat status epilepticus (SE). An original system was therefore developed to measure blood concentrations of MDZ and 1‐hydroxymidazolam (1‐OHMDZ) as the main metabolite on high‐performance liquid chromatography.

Methods:  This system was established through inspection of chromatograms, calibration curves and coefficient of correlations of MDZ. The clinical course of 11 SE patients, ranging from 4 months to 10 years of age, are described. These patients were treated with MDZ and measured at each blood concentration of MDZ. Moreover, patients were evaluated on cranial computed tomography and magnetic resonance imaging and video electroencephalogram (EEG), and it was determined that their seizures disappeared in accordance with the disappearance of convulsions and interictal EEG findings.

Results
:  Reproducibility was good with this system. The standard curves of MDZ and 1‐OHMDZ were almost straight, and the correlation coefficients of MDZ and 1‐OHMDZ were r= 0.9999 and r= 0.9998, respectively. The convulsions in nine of 11 SE patients disappeared without side‐effects and the blood concentrations of MDZ in all the patients were measured. The mean peak blood concentrations of MDZ and 1‐OHMDZ were higher than those reported in other studies.

Conclusions:  The clinical utility of this system has been demonstrated. An index to evaluate the efficacy and safety of MDZ is necessary, and MDZ blood concentrations measured on the present original precise measuring system could help in establishing a plan to successfully treat SE.
Colistimethate sodium therapy for multidrug‐resistant isolates in pediatric patients
Authors: Celebi Solmaz , Hacimustafaoglu Mustafa , Koksal Nilgun , Ozkan Hilal , Çetinkaya Merih
Published: December 2009

Aim:  The aim of the present study was to assess the efficacy and safety of colistimethate sodium therapy in multidrug‐resistant nosocomial infections caused by Pseudomonas aeruginosa or Acinetobacter baumannii in neonates and children.

Methods:  Pediatric patients hospitalized at the Uludag University Hospital who had nosocomial infections caused by multidrug‐resistant P. aeruginosa or A. baumannii, were enrolled in the study. Colistimethate sodium at a dosage of 50–75 × 103 U/kg per day was given i.v. divided into three doses.

Results:  Fifteen patients received 17 courses of colistimethate sodium for the following infections: ventilator‐associated pneumonia (n= 14), catheter‐related sepsis (n= 1) and skin and soft‐tissue infection (n= 2). The mean age of patients was 53.2 + 74.7 months (range, 8 days–15 years) and 60% were male. Mortality was 26.6%.

Conclusion:  Colistimethate sodium appears to be safe and effective for the treatment of severe infections caused by multidrug‐resistant P. aeruginosa or A. baumannii in pediatric patients.
Benchmarking opioids in the last 24 hours of life
Authors: Ensor B. R. , Middlemiss T. P.
Published: December 2009

Background/Aims: Opioid dosages are titrated against symptoms with large variations between patients. For self‐assessment of prescribing, and for clinical governance, it is important to know the normal prescribing patterns across New Zealand (NZ). The aims of this study were to document opioids and dosages given to patients in the last 24 h of life to identify normal practice and allow prescribers to reflect on their own practice.

Methods: A cross‐sectional benchmarking design with retrospective chart review was carried out among 14 NZ hospices. Data (n= 352) on opioid dosages were analysed for inter‐hospice variability (anova). Parenteral morphine equivalent daily dose was used to analyse the dosage of different opioids.

Results: Overall, 95% of dying patients received an opioid. Of these 71% received morphine, 17% fentanyl, 10% methadone 9.5% oxycodone. The dosages delivered are conservative compared with international data, with a geometric mean of 47.8 mg. There was no significant difference in mean dosages of opioids prescribed between hospice teams. There was, however, a significant difference between the dosage of opioid for those on the Liverpool Care Pathway for the Care of the Dying and those who were not (63.1–44.4 mg), and between those with malignant and non‐malignant disease (53.8–26.0 mg). Opioid footprints show different hospices have different patterns of opioid use.

Conclusion: The parameters of what normal opioid prescribing is in the last days of life in NZ can be described from these data. There is value in repeating this exercise both for clinical governance and for professional reflection and self‐assessment.
Glycaemic goals in patients with type 2 diabetes: current status, challenges and recent advances
Authors: Khunti K. , Davies M.
Published: December 2009

Recommendations for the management of type 2 diabetes include rigorous control of blood glucose levels and other risk factors, such as hypertension and dyslipidaemia. In clinical practice, many patients do not reach goals for glycaemic control. Causes of failure to control blood glucose include progression of underlying pancreatic β‐cell dysfunction, incomplete adherence to treatment (often because of adverse effects of weight gain and hypoglycaemia) and reluctance of clinicians to intensify therapy. There is increasing focus on strategies that offer potential to improve glycaemic control. Structured patient education has been shown to improve glycaemic control and other cardiovascular risk factors in people with type 2 diabetes. Payment of general practitioners by results has been shown to improve glycaemic control. New classes of glucose‐lowering agents have expanded the treatment options available to clinicians and patients and include the dipeptidyl peptidase 4 (DPP‐4) inhibitors and glucagon‐like peptide‐1 (GLP‐1) receptor agonists. These new classes of therapy and other strategies outlined above could help clinicians to individualize treatment and help a greater proportion of patients to achieve long‐term control of blood glucose.