bluuebunny/crossref_metadata_2025_split huggingface dataset:
Posterior reversible encephalopathy syndrome: a report of a case with atypical features
Authors: Pratap J. N. , Down J. F. 
Published: August 2008

SummaryWe report a case of a young woman presenting with profound depression of consciousness and intra‐uterine death in the late stages of an unbooked pregnancy. She proceeded to develop features of cardiovascular, renal, hepatic and haematological failures. The patient was challenging to manage in view of uncertainty regarding the underlying cause, and required multidisciplinary consultation. A diagnosis was subsequently made of posterior reversible encephalopathy syndrome in the context of pre‐eclampsia. We review the typical presentation and wide‐ranging associations of this recently described clinico‐neuroradiological syndrome, and look at how appropriate management may lead to rapid resolution of its often life‐threatening features. We highlight the importance to anaesthetists and critical care physicians of recognising even atypical cases such as this one in view of key differences in management from similarly presenting conditions.
No difference between strontium ranelate (SR) and calcium/vitamin D on bone turnover markers in women with established osteoporosis previously treated with teriparatide: a randomized controlled trial
Authors: Anastasilakis Athanasios D. , Goulis Dimirtios G. , Polyzos Stergios A. , Gerou Spiridon , Ballaouri Iris , Efstathiadou Zoe , Kita Marina , Avramidis Avraam 
Published: August 2008

SummaryObjective   To evaluate the effect of strontium ranelate (SR) on bone turnover markers in women with established osteoporosis previously treated with teriparatide (TPTD – recombinant human PTH 1–34).Design   patients: Twenty‐two postmenopausal Caucasian women (aged 65·7 ± 1·7 years) with established osteoporosis previously treated with TPTD 20 µg daily for 18 months were randomly assigned to receive either SR (SR group, n = 11) or calcium and vitamin D (control group, n = 11).Measurements   Blood samples for serum N‐terminal propeptide of type 1 collagen (P1NP), C‐terminal telopeptide of type 1 collagen (CTx) and total alkaline phosphatase (ALP) were obtained from all women before (pre‐TPTD) and after (post‐TPTD) TPTD administration, as well as 6 months after SR or calcium/vitamin D administration (post‐SR/Ca).Results   Serum P1NP, CTx and total ALP increased significantly after TPTD treatment and decreased at the end of the study in both SR and control groups, with no difference between them.Conclusions   SR following TPTD administration acts predominantly as an antiresorptive agent with no evidence of additional osteoanabolic action. In this setting, SR is not more effective than Ca/vitamin D as far as bone turnover markers are concerned.
The Pro12Ala PPARγ gene polymorphism: possible modifier of the activity and severity of thyroid‐associated orbitopathy (TAO)
Authors: Alevizaki Maria , Mantzou Emily , Cimponeriu Adriana , Saltiki Katerina , Philippou George , Wiersinga Wilmar 
Published: August 2008

SummaryObjective  The PPARγ transcription factor, is involved in both adipogenesis and inflammation, which have been implicated in the pathogenesis of thyroid‐associated orbitopathy (TAO). The aim of this study was to explore the possibility that the Pro12Ala polymorphism of the PPARγ gene, associated with a modified transcriptional activity, might be affecting the severity of TAO.Subjects and design   We studied two cohorts of patients with Graves’ disease (GD): Group 1 comprised 172 patients of Dutch ethnic origin with TAO, who attended the outpatients’ clinic, Department of Endocrinology and Orbital Centre of the Academic Medical Centre, Amsterdam. Group 2 comprised 93 consecutive patients with GD of Greek ethnic origin, who did not have TAO. In group 1, exophthalmometry measurements, lid oedema, diplopia (n = 172) and clinical activity score (CAS) (n = 110), always assessed by the same group of three investigators, were recorded. Autoantibody levels were measured.Results  Allele frequency was 11·5%. There was no difference in the distribution of the polymorphism between GD patients with and without TAO. Among group 1 patients proptosis was significantly lower in Pro12Ala carriers (20·1 ± 3·3 vs. 22·1 ± 3·1, P = 0·003, t‐test). PPARγ polymorphism carriers had lower TSH‐Rab levels (mean rank 61·8 vs. 83·2, P = 0·015) and lower CAS (available in 110 patients) (mean rank 38·9 vs. 55·4, P = 0·022, M–W‐test). The frequency of the polymorphism decreased with increasing CAS (P = 0·023 linear by linear association). Multivariate analysis (step) showed that the association of either proptosis or CAS with the PPARγ gene variant remained significant when age, smoking and TSH‐Rab levels were taken into account (P < 0·01).Conclusions  The distribution of the Pro12Ala PPARγ gene polymorphism is equally present in patients with GD with or without TAO. Among patients with TAO this polymorphism is associated with less‐severe and less‐active disease.
Relationships between deforestation, riparian forest buffers and benthic macroinvertebrates in neotropical headwater streams
Authors: LORION CHRISTOPHER M. , KENNEDY BRIAN P. 
Published: August 2008

Summary1. Few studies have evaluated the effectiveness of riparian buffers in the tropics, despite their potential to reduce the impacts of deforestation on stream communities. We examined macroinvertebrate assemblages and stream habitat characteristics in small lowland streams in southeastern Costa Rica to assess the impacts of deforestation on benthic communities and the influence of riparian forest buffers on these effects. Three different stream reach types were compared in the study: (i) forested reference reaches, (ii) stream reaches adjacent to pasture with a riparian forest buffer at least 15 m in width on both banks and (iii) stream reaches adjacent to pasture without a riparian forest buffer.2. Comparisons between forest and pasture reaches suggest that deforestation, even at a very local scale, can alter the taxonomic composition of benthic macroinvertebrate assemblages, reduce macroinvertebrate diversity and eliminate the most sensitive taxa. The presence of a riparian forest buffer appeared to significantly reduce the effects of deforestation on benthic communities, as macroinvertebrate diversity and assemblage structure in forest buffer reaches were generally very similar to those in forested reference reaches. One forest buffer reach was clearly an exception to this pattern, despite the presence of a wide riparian buffer.3. The taxonomic structure of macroinvertebrate assemblages differed between pool and riffle habitats, but contrasts among the three reach types in our study were consistent across the two habitats. Differences among reach types also persisted across three sampling periods during our 15‐month study.4. Among the environmental variables we measured, only stream water temperature varied significantly among reach types, but trends in periphyton abundance and stream sedimentation may have contributed to observed differences in macroinvertebrate assemblage structure.5. Forest cover was high in all of our study catchments, and more research is needed to determine whether riparian forest buffers will sustain similar functions in more extensively deforested landscapes. Nevertheless, our results provide support for Costa Rican regulations protecting riparian forests and suggest that proper riparian management could significantly reduce the impacts of deforestation on benthic communities in tropical streams.
Isolated remnant or recent introduction? Estimating the provenance of Yellingbo Leadbeater's possums by genetic analysis and bottleneck simulation
Authors: HANSEN BIRGITA D. , TAYLOR ANDREA C. 
Published: August 2008

AbstractEffective conservation management requires that genetically divergent populations potentially harbouring important local adaptations be identified and maintained as separate management units. In the case of the endangered Australian Leadbeater's possum (Gymnobelideus leadbeateri), an arboreal marsupial endemic to Victoria, uncertainty over the evolutionary origin of a potentially important extant wild population recently discovered in atypical habitat (lowland swamp) at Yellingbo is hampering such efforts. The population is rumoured to be a recent introduction. Microsatellite allele frequencies at Yellingbo differed substantially from those in sampled populations in montane ash forest (FST between 0.23 and 0.36), and Bayesian clustering analyses of genotypes strongly separated them (K = 2). We conducted a suite of bottlenecking tests which all indicated that Yellingbo had undergone a recent reduction in size. The extent to which the distinctiveness of Yellingbo animals might be expected solely through bottlenecking associated with a recent introduction, was tested by simulating population–history scenarios seeded with genotypes from candidate wild and captive sources. No bottleneck scenario reproduced anything approaching the genetic distinction of the Yellingbo population, with all structure analyses placing Yellingbo in a separate cluster to simulated populations (K = 2, minimum FST = 0.13). These results suggest that Yellingbo does not share recent ancestry with other extant populations and instead may be a remnant of an otherwise extinct gene pool. Importantly, this may include genes involved in adaptation to a lowland swamp environment, substantially adding to the conservation importance of this population, and suggesting that separate management may be prudent until evidence suggests otherwise.
Structural basis of specific TraD–TraM recognition during F plasmid‐mediated bacterial conjugation
Authors: Lu Jun , Wong Joyce J. W. , Edwards Ross A. , Manchak Jan , Frost Laura S. , Glover J. N. Mark 
Published: August 2008

SummaryF plasmid‐mediated bacterial conjugation requires interactions between a relaxosome component, TraM, and the coupling protein TraD, a hexameric ring ATPase that forms the cytoplasmic face of the conjugative pore. Here we present the crystal structure of the C‐terminal tail of TraD bound to the TraM tetramerization domain, the first structural evidence of relaxosome‐coupling protein interactions. The structure reveals the TraD C‐terminal peptide bound to each of four symmetry‐related grooves on the surface of the TraM tetramer. Extensive protein–protein interactions were observed between the two proteins. Mutational analysis indicates that these interactions are specific and required for efficient F conjugation in vivo. Our results suggest that specific interactions between the C‐terminal tail of TraD and the TraM tetramerization domain might lead to more generalized interactions that stabilize the relaxosome‐coupling protein complex in preparation for conjugative DNA transfer.
Molecular basis of halorespiration control by CprK, a CRP‐FNR type transcriptional regulator
Authors: Levy Colin , Pike Katharine , Heyes Derren J. , Joyce M. Gordon , Gabor Krisztina , Smidt Hauke , van der Oost John , Leys David 
Published: August 2008

SummaryCertain bacteria are able to conserve energy via the reductive dehalogenation of halo‐organic compounds in a respiration‐type metabolism. The transcriptional regulator CprK from Desulfitobacterium spp. induces expression of halorespiratory genes upon binding of o‐chlorophenol ligands and is reversibly inactivated by oxygen through disulphide bond formation. We report crystal structures of D. hafniense CprK in the ligand‐free (both oxidation states), ligand‐bound (reduced) and DNA‐bound states, making it the first member of the widespread CRP‐FNR superfamily for which a complete structural description of both redox‐dependent and allosteric molecular rearrangements is available. In conjunction with kinetic and thermodynamic ligand binding studies, we provide a model for the allosteric mechanisms underpinning transcriptional control. Amino acids that play a key role in this mechanism are not conserved in functionally distinct CRP‐FNR members. This suggests that, despite significant structural homology, distinct allosteric mechanisms are used, enabling this protein family to control a very wide range of processes.
The chloroplast avoidance response decreases internal conductance to CO2 diffusion in Arabidopsis thaliana leaves
Authors: THOLEN DANNY , BOOM CAROLINA , NOGUCHI KO , UEDA SHINGO , KATASE TAKAO , TERASHIMA ICHIRO 
Published: August 2008

ABSTRACTThe relationship between chloroplast arrangement and diffusion of CO2 from substomatal cavities to the chloroplast stroma was investigated in Arabidopsis thaliana. Chloroplast position was manipulated by varying the amount of blue light and by cytochalasin D (CytD) treatment. We also investigated two chloroplast positioning mutants. Chloroplast arrangement was assessed by the surface area of chloroplasts adjacent to intercellular airspaces (Sc). Although it has been previously shown that long‐term acclimation to high light is linked with a large Sc, we found that the short‐term chloroplast avoidance response reduces Sc. This effect was not apparent in the blue‐light‐insensitive phot2 mutant, which did not show the avoidance response. As expected, the smaller Sc induced by the avoidance response was coupled to a similar decrease in internal conductance. This reduction in internal conductance resulted in an increased limitation of the rate of photosynthesis. The limiting effect of Sc on internal conductance and photosynthesis was also shown in chup1, a mutant with a constant small Sc as the result of an unusual chloroplast arrangement. We conclude that chloroplast movements in A. thaliana can rapidly alter leaf morphological parameters, and this has significant consequences for the diffusion of CO2 through the mesophyll.
Divergent timing of egg‐laying may maintain life history polymorphism in potentially multivoltine insects in seasonal environments
Authors: VÄLIMÄKI P. , KIVELÄ S. M. , JÄÄSKELÄINEN L. , KAITALA A. , KAITALA V. , OKSANEN J. 
Published: August 2008

AbstractThe length of the favourable season determines voltinism in insect populations. In some insects, there is variation in fecundity and timing of reproduction among females. If the length of the favourable season does not allow all offspring to develop into adults without diapause, the benefits of high early fecundity may outweigh the associated cost of low lifetime fecundity. We tested this by exploring mating frequencies of Pieris napi females along a latitudinal gradient in different generations. Pieris napi is a bivoltine butterfly, and genetically polyandrous females enjoy higher lifetime fecundity than monandrous ones. Polyandry is, however, coupled with a relatively low early fecundity. We found that monandrous females are more likely to produce an additional generation than polyandrous ones under conditions that allow production of only a partial summer generation. Monandrous females were also the first to emerge and slightly over‐represented in the summer generation under conditions that allow the development of a complete summer generation. Further, a stochastic model shows that variation in the timing of reproduction between strategies is sufficient to explain the observed patterns. Thus, seasonality may counter‐select against polyandry, or more generally against low early reproductive rate, and promote maintenance of polymorphism in life history strategies.
Maximized virulence in a sterilizing pathogen: the anther‐smut fungus and its co‐evolved hosts
Authors: SLOAN D. B. , GIRAUD T. , HOOD M. E. 
Published: August 2008

AbstractHost sterilization is a common feature of sexually transmitted diseases (STDs). Because host reproductive failure may free up resources for pathogen reproduction and transmission, theory predicts that selection on sterilizing pathogens will favour maximum virulence (i.e. complete sterilization). We examined patterns of infection in sexually transmitted anther‐smut fungi (Microbotryum) on four of their host species in the Caryophyllaceae. Using controlled fungal matings and experimental inoculations, we compared disease expression in inoculations ranging from host‐specific pathogens to hybrids and cross‐species treatments. Our data support the existence of host‐specific sibling species within the genus Microbotryum based on a low infection rate from cross‐inoculations and reduced fitness for hybrid pathogens. These patterns of host specificity and reproductive isolation, however, were not absolute. We did observe some successful cross‐species and hybrid infections, but the expression of disease was frequently incomplete, including only partial host sterilization and the failed dehiscence of pathogen spores. The prevalence of these maladapted disease phenotypes may greatly inhibit the emergence of novel host pathogen combinations. Infections by hybrid pathogen genotypes were intermediate, in terms of both infection rate and the normality of disease symptoms, between host‐specific and cross‐inoculated pathogens. In addition, the frequency with which hybrid and cross‐inoculated anther‐smut pathogens were able to infect but not sterilize new hosts supports the prediction that sterilizing STDs are under selection to maximize virulence in natural populations.
Increased melibiose/rhamnose ratio in bile of rats with acute cholestasis
Authors: Tomsik Pavel , Sispera Ludek , Rezacova Martina , Niang Mohamed , Stoklasova Alena , Cerman Jaroslav , Knizek Jiri , Brcakova Eva , Cermanova Jolana , Micuda Stanislav 
Published: August 2008

AbstractBackground and Aim:  Melibiose/rhamnose permeability test is used for noninvasive intestinal mucosa barrier testing. However, the possible escape route of the absorbed saccharides through either intact or impaired blood–biliary barriers has not so far been explored. The objective of the present study was therefore two‐fold: First, to describe in detail the biliary pharmacokinetics of melibiose and rhamnose in rats; second, to evaluate the changes of both sugars' pharmacokinetics upon impairment of the blood–biliary barrier by acute extrahepatic cholestasis in rats.Methods:  Bile duct obstructed (BDO), sham‐operated and intact (unoperated) male Wistar rats were administered, 24 h after the appropriate intervention, with a single intravenous dose of melibiose and rhamnose, and a 4‐h pharmacokinetic study was performed.Results:  In intact animals, the biliary excretion of melibiose and rhamnose was only 0.06% and 0.4% of the administered dose, respectively, while the urinary excretion accounted for 70.6% and 61.7%, respectively. In BDO animals, the biliary excretion rate of both saccharides, especially that of melibiose, was increased with a consequent 4.4‐fold rise of the biliary melibiose/rhamnose ratio, the accepted paracellular permeability indicator. Both, the renal clearance of melibiose and the urinary melibiose/rhamnose ratio remained uninfluenced by cholestasis.Conclusion:  The present study is the first to describe in detail pharmacokinetic parameters and the biliary excretion of melibiose and rhamnose in healthy and cholestatic rats. The altered melibiose/rhamnose biliary excretion ratio in BDO rats indicates that the test is able to detect the impairment of the blood–biliary barrier in acute extrahepatic cholestasis.
Case‐crossover study of hospitalization for acute hepatitis in Chinese herb users
Authors: Lee Chang‐Hsing , Wang Jung‐Der , Chen Pau‐Chung 
Published: August 2008

AbstractBackground and Aim:  Despite the increase in popularity of herbal products, there is growing concern over potential health hazards caused by the Chinese herbal medicines (CHMs) that are regularly reimbursed under the National Health Insurance system in Taiwan. This study attempts to determine the association between CHM prescriptions and acute hepatitis–related hospitalizations.Methods:  A case‐crossover study was designed on 200 000 randomly selected individuals from the National Health Insurance Research Database who were then followed from 1997 to 2002. All medications taken in the 30‐ and 60‐day periods prior to hospitalization were explored and compared with four control periods (the 180‐ and 360‐day periods prior to and after the hospitalization). A conditional logistic regression model was then constructed to determine the odds of CHM being prescribed during these risk periods.Results:  There were a total of 12 cases with nonviral, nonalcoholic hepatitis patients who took CHM prescriptions during the 30‐day risk or control periods. After adjustment for conventional hepatotoxic drugs, the odds ratio during the 30‐day risk period was 3.4 (95% confidence interval [CI]: 1.1, 9.8) for nonviral, nonalcoholic acute hepatitis. A detailed historical review of CHMs for each patient revealed that the odds ratio increased to 4.2 for those prescribed formulae containing Radix Paeoniae (95% CI: 1.1, 15.7) and Radix Glycyrrhizae (95% CI: 1.2, 15.2).Conclusions:  Chinese herbal users revealed a slightly increased risk of acute hepatitis. We therefore recommend pharmacovigilance and active surveillance for CHMs suspected with hepatotoxicity.
Transition in chronic illness: Who is going where?
Authors: Steinbeck Katharine S , Brodie Lynne , Towns Susan J 
Published: August 2008

Aim:  With increasing survival rates for chronic childhood illness, there has been an increasing focus on the transition of clinical care from paediatric to adult services. Data regarding patient numbers are essential for strategic planning and for optimal management. We report on a data collection exercise from the New South Wales Greater Metropolitan Clinical Taskforce Transition Program.Methods:  Data were collected between August 2004 and October 2005 through face‐to‐face interviews with over 200 clinicians in 68 clinical services in tertiary paediatric hospitals in New South Wales, providing information on approximately 4200 patients.Results:  Sixty‐eight services kept a database on patients with chronic illness but less than half were electronic. Eight services (12%) could specifically identify patients in the active phase of transition on their databases. The five most prevalent clinical groups requiring transition to adult specialist health care (excluding cerebral palsy and developmental disability) were diabetes, other endocrinology, neurology, spina bifida and gastroenterology.Conclusions:  There are large numbers of young people with chronic illness and disability who need effective transition to long‐term adult care. This study has enabled the identification of paediatric aspects of the transition process that require attention.