bluuebunny/crossref_metadata_2025 huggingface dataset:
Genotype‐by‐genotype specificity remains robust to average temperature variation in an aphid/endosymbiont/parasitoid system
Authors: Cayetano L. , Vorburger C.
Published: May 2013

Genotype‐by‐genotype interactions demonstrate the existence of variation upon which selection acts in host–parasite systems at respective resistance and infection loci. These interactions can potentially be modified by environmental factors, which would entail that different genotypes are selected under different environmental conditions. In the current study, we checked for a G × G × E interaction in the context of average temperature and the genotypes of asexual lines of the endoparasitoid wasp Lysiphlebus fabarum and isolates of Hamiltonella defensa, a protective secondary endosymbiont of the wasp's host, the black bean aphid Aphis fabae. We exposed genetically identical aphids harbouring different isolates of H. defensa to three asexual lines of the parasitoid and measured parasitism success under three different temperatures (15, 22 and 29 °C). Although there was clear evidence for increased susceptibility to parasitoids at the highest average temperature and a strong G × G interaction between the host's symbionts and the parasitoids, no modifying effect of temperature, that is, no significant G × G × E interaction, was detected. This robustness of the observed specificity suggests that the relative fitness of different parasitoid genotypes on hosts protected by particular symbionts remains uncomplicated by spatial or temporal variation in temperature, which should facilitate biological control strategies.
Colour‐variable birds have broader ranges, wider niches and are less likely to be threatened
Authors: Delhey K. , Smith J. , Peters A.
Published: May 2013

Coloration fulfils a variety of adaptive functions in animals. Colour variability, both between and within species, can be caused by different colours being favoured for different functions and in different environments. Thus, species with highly variable coloration may have greater potential to persist in new and changing environments. As a consequence, such colour‐variable species may be more able to adapt, colonize new areas and niches, occupy larger ranges, speciate more readily and in general be less vulnerable to environmental change and extinction. These predictions have been supported by comparative analyses on amphibians and reptiles. However, as coloration in ectotherms plays a key role in thermoregulation, it is unclear whether these results can be generalized to endotherms, such as birds and mammals. Here, we test the hypothesis that more colour‐variable endotherms occupy larger ranges/niches and are less vulnerable to the threat of extinction by focussing on colour variation in Australian parrots and passerine birds. As predicted, colour variability was correlated with range size (parrots and passerines) and niche breadth (dietary heterogeneity, parrots only). These relationships support the predicted link between colour variability and adaptability, whereby range size and niche breadth may be a cause of colour variability or vice versa. Irrespective, and as predicted, colour variability was lower in threatened species, even after statistically controlling for other confounding variables. Hence, our study supports the hypothesis that colour‐variable species in general are more resilient to environmental change.
The evolution of queen pheromones in the ant genus Lasius
Authors: Holman L. , Lanfear R. , d'Ettorre P.
Published: May 2013

Queen pheromones are among the most important chemical messages regulating insect societies yet they remain largely undiscovered, hindering research into interesting proximate and ultimate questions. Identifying queen pheromones in multiple species would give new insight into the selective pressures and evolutionary constraints acting on these ubiquitous signals. Here, we present experimental and comparative evidence that 3‐methylalkanes, hydrocarbons present on the queen's cuticle, are a queen pheromone throughout the ant genus Lasius. Interspecific variation in the chemical profile is consistent with 3‐methylalkanes evolving more slowly than other types of hydrocarbons, perhaps due to differential selection or evolutionary constraints. We argue that the sensory ecology of the worker response imposes strong stabilizing selection on queen pheromones relative to other hydrocarbons. 3‐Methylalkanes are also strongly physiologically and genetically coupled with fecundity in at least one Lasius species, which may translate into evolutionary constraints. Our results highlight how honest signalling could minimize evolutionary conflict over reproduction, promoting the evolution and maintenance of eusociality.
Early development of marine catfishes (Ariidae): from mouth brooding to the release of juveniles in nursery habitats
Authors: Lima A. R. A. , Barletta M. , Dantas D. V. , Ramos J. A. A. , Costa M. F.
Published: May 2013

The development and allometric growth patterns of the ariid catfishes Cathorops spixii and Cathorops agassizii were studied from neurula embryos to juveniles. The ontogenetic sequence revealed that prior to hatching, embryos of both species are well developed, and their axial and appendicular skeletons are well ossified. Embryos of both species grow slowly longitudinally, but positively allometric growth (growth coefficient, β1 > 1) was observed in head width and eye diameter. It is hypothesized that these growth patterns might be related to functional priorities for the development of sensory organs, such as the inner ears (otoliths), the Weberian apparatus, eyes and nostrils, during the embryonic period. The first appearance of vertebrae and otoliths, as well as the ossification of otoliths and the Weberian apparatus, occur earlier in embryos of C. agassizii than in embryos of C. spixii. After hatching, mouth‐brooded free embryos of both species grow isometrically. Negatively allometric growth was observed in head width and eye diameter during the yolk‐sac period, which is expected given that the sensory organs are already formed. Free embryos of C. agassizii are distinguishable from those of C. spixii by their larger eyes, longer snouts, longer heads and heavier yolk sacs. The end of the yolk‐sac period is characterized by a direct change from free embryo to juvenile, without a true larval period. The juveniles of the two species can also be distinguished from each other by the larger eyes of C. agassizii compared with C. spixii, as in adult fishes.
Cognitive and Physical Health of the Older Populations of England, the United States, and Ireland: International Comparability of The Irish Longitudinal Study on Ageing
Authors: Savva George M. , Maty Siobhan C. , Setti Annalisa , Feeney Joanne
Published: May 2013

This article discusses the contribution that international comparisons of the health and well‐being of older people make. The comparability of the “HRS family” of studies that have been modeled on the U.S. Health and Retirement Study (HRS) is discussed. The Irish Longitudinal Study of Ageing (TILDA) is introduced, and the comparability of TILDA data with respect to the HRS family and other studies is described, along with what TILDA will add to international aging research. Data from the 2010 waves of TILDA, HRS and the English Longitudinal Study of Ageing are used to compare the physical and cognitive health of older Irish adults with that of the U.S. and English populations. The study shows that the physical and cognitive health of older people in Ireland is closer to that of their English counterparts than of those in the United States and that similar health inequalities exist in all three countries.
Design and Methodology of The Irish Longitudinal Study on Ageing
Authors: Whelan Brendan J. , Savva George M.
Published: May 2013

Objectives

To provide comprehensive data on older people in Ireland and new insights into the causal processes underlying the aging transformation.

Design

The Irish Longitudinal Study on Ageing (TILDA) is a population‐representative prospective cohort study with baseline assessment conducted between October 2009 and Febraury 2011 and follow‐up waves planned every 2 years. Participants were sampled in geographic clusters, with each member of the Irish population aged 50 and older having an equal probability of being invited to participate in the study.

Setting

Community‐living population of the Republic of Ireland aged 50 and older.

Participants

Eight thousand one hundred seventy‐five participants aged 50 and older at time of interview participated in the study, along with 329 spouses or partners younger than 50.

Measurements

The Irish Longitudinal Study on Ageing includes detailed assessments of the mental and physical health and social and financial circumstances of participants, which are assessed in a home interview, a self‐completion questionnaire, and a detailed health assessment that takes place at a dedicated health center or in the respondent's home.

Results

The response rate was 62.0%, with response rate varying according to educational attainment. Data from the first wave of data collection are available for researchers at the Irish Social Sciences Data Archive.

Conclusion

The Irish Longitudinal Study on Ageing provides an opportunity to study the interactions between the health and social and economic circumstances of the older population in a nationally representative sample.
Students entering internship show readiness in the nutrition care process
Authors: Baker S. D. , Cotugna N.
Published: May 2013

Background

The British Dietetic Association and the International Confederation of Dietetic Associations are developing an international model for dietetics practice as an aid in providing evidence‐based practice. In the USA, undergraduate programmes are mandated by the Academy of Nutrition and Dietetics (formerly the American Dietetic Association) to incorporate the nutrition care process (NCP) into the curriculum so that students can use the process during their dietetic internship and later practice. The present study aimed to assess interns’ readiness in the NCP prior to beginning a dietetic internship.

Methods

Before starting the internship, the 40 interns in the 2009–2010 class of a university‐based internship were sent an e‐mail requesting they complete an online survey. Questions inquired about their NCP background with respect to: academic preparation, work or volunteer experiences, knowledge and confidence in ability to apply the NCP. Survey results were analysed with SPSS statistical software (SPSS Inc., Chicago, IL, USA).

Results

The 39 interns completing the survey indicated they had prior exposure to the NCP. All but one reported that their academic coursework covered the NCP. Approximately half of the interns worked or volunteered in settings that used the NCP. Overall, students correctly answered most of the questions assessing their basic knowledge in the NCP. Thirty‐seven of the 39 interns had some confidence or felt confident in their ability to apply the NCP during internship rotations.

Conclusions

This distance internship attracts students from all over the USA, and so the findings of the present study shed light on current undergraduate preparation in the NCP.
The Biophysical Performance of Argentina (1970–2009)
Authors: Manrique Pedro Luis Perez , Brun Julien , González‐Martínez Ana Citlalic , Walter Mariana , Martínez‐Alier Joan
Published: May 2013

The biophysical features of the Argentinean economy are examined using a social metabolism approach. A material flow analysis (MFA) for this economy was conducted for the period 1970–2009. Results show that Argentina follows a resource‐intensive and export‐oriented development model with a persistent physical trade deficit. Also, Argentina's terms of trade (the average weight in tonnes of imports that can be purchased through the sale of 1 tonne of exports) show a declining trend in the period of study.

Argentina's economy shows a pattern typical of countries whose economies are based primarily on exports. Comparisons between Argentina's metabolic profile and the metabolic profile of other countries in Latin America and of Australia and Spain show that the Argentinean economy presents the same pattern as other Latin American exporting economies, and its terms of trade are opposite to those of industrialized economies.
Transactional Process of African American Adolescents’ Family Conflict and Violent Behavior
Authors: Choe Daniel Ewon , Zimmerman Marc A.
Published: May 2013

This is the first longitudinal study of urban African American adolescents that has examined bidirectional effects between their family conflict and violent behavior across all of high school. Structured interviews were administered to 681 students each year in high school at ages 15, 16, 17, and 18 years. We used structural equation modeling to test a transactional model and found bidirectional effects between family conflict and violent behavior across the middle years of high school, while accounting for sex and socioeconomic status. Findings suggest a reciprocal process involving interpersonal conflict in African American families and adolescent engagement in youth violence.
Influence of the formulation on the maximum tolerated doses of brain targeted nanoparticles of gallic acid by oral administration in Wistar rats
Authors: Nagpal Kalpana , Singh Shailendra Kumar , Mishra Dinanath
Published: May 2013

Objectives

The objective of the present investigation was to study the effect of pure gallic acid (GA) and its Tween 80 coated chitosan nanoparticles (cGANP) on the maximum tolerated dose (MTD) using Wistar rats.

Methods

The animals were administered with increasing doses (dose increasing rate = 10%) of GA and cGANP orally for 28 consecutive days until the MTD was found. The animals were monitored for bodyweight, weight indices, behavioural, biochemical and histopathological changes.

Key findings

The MTD was found to be 750 mg/kg for GA and was increased to 825 mg/kg for cGANP, which indicated a significantly greater tolerance of cGANP. Slight behavioural and biochemical changes were observed above the MTD. At the MTD no significant behavioural, biochemical, histopathological changes were observed.

Conclusions

The brain targeted nanoparticles displayed considerable improvement in the tolerance profile of the drug as compared with the free drug.
Temporally separated bilateral anal sac gland carcinomas in four dogs
Authors: Bowlt K. L. , Friend E. J. , Delisser P. , Murphy S. , Polton G.
Published: May 2013

Anal sac gland carcinoma arising from the apocrine secretory epithelium in the anal sac wall, is locally invasive and highly metastatic. The majority of anal sac gland carcinomas are unilateral on presentation, but bilateral tumours have been identified. This case series presents the outcome of four unique cases of unilateral anal sac gland carcinoma which subsequently developed contralateral anal sac gland carcinoma 50 to 390 days after removal of the initial tumour. Median survival was 1035 days after initial diagnosis and 807 days after diagnosis of the second anal sac gland carcinoma.
Arterial blood gas parameters in pet rabbits anaesthetized using a combination of fentanyl‐fluanisone‐midazolam‐isoflurane
Authors: Benato L. , Chesnel M. , Eatwell K. , Meredith A.
Published: May 2013

Objectives

Blood gas analysis is a well‐recognized method to monitor pulmonary function, blood oxygenation, ventilation and acid–base status during general anaesthesia. The aim of this study was to report blood gas analysis results in pet rabbits (Oryctolagus cuniculus) obtained during general anaesthesia using a portable clinical analyser.

Methods

Thirty‐two rabbits were premedicated with 0·2 mL/kg fentanyl and fluanisone. Anaesthesia was induced with 0·2 mg/kg midazolam and maintained with 2% isoflurane in oxygen via endotracheal tube. Arterial blood samples were taken from the central ear artery 10 minutes after induction of anaesthesia.

Results

Respiratory acidaemia was observed during anaesthesia. Mean ±sd (range) arterial blood pH was 7·33 ±0·08 (7·15 to 7·48). PaCO2 and PaO2 were, respectively, 55·02 ±10·5 (37·7 to 92·1) mmHg and 370·0 ±120·5 (67 to 561) mmHg. Base excess was 2·8 ±3·6 (−3 to 11) mmol/L, HCO3 was 28·73 ±3·07 (23·7 to 35·4) mmol/L and TCO2 was 30·4 ±3·2 (25 to 37) mmol/L. None of the rabbits developed haematoma during arterial blood collection or ischaemia of the pinna during the hospitalization period.

Clinical Significance

Arterial blood gas analysis is a safe and easy to perform diagnostic technique that can contribute to improved safety of rabbit anaesthesia, by providing information on the respiratory and metabolic status of the patient.
A Comprehensive Pathological Survey of Duodenal Biopsies from Dogs with Diet‐Responsive Chronic Enteropathy
Authors: Walker D. , Knuchel‐Takano A. , McCutchan A. , Chang Y‐M. , Downes C. , Miller S. , Stevens K. , Verheyen K. , Phillips A.D. , Miah S. , Turmaine M. , Hibbert A. , Steiner J.M. , Suchodolski J.S. , Mohan K. , Eastwood J. , Allenspach K. , Smith K. , Garden O.A.
Published: May 2013

Background

The detailed pathological phenotype of diet‐responsive chronic enteropathy (CE) and its modulation with dietary therapy remain poorly characterized.

Hypothesis/Objectives

Key mucosal lesions of diet‐responsiveCEresolve with dietary therapy.

Methods

This was a prospective observational study of 20 dogs with diet‐responsiveCE. Endoscopic duodenal biopsies collected before and 6 weeks after the start of a dietary trial were assessed by means of qualitative and quantitative histopathological, immunohistochemical, and ultrastructural criteria. Control duodenal biopsies were obtained from 10 healthy Beagle dogs on 1 occasion.

Results

Compared with control dogs, theCEdogs had higher villus stunting scores and higher overallWSAVAscores, a lower villus height‐to‐width ratio, and higher lamina propria density of eosinophils. TheCEdogs also had ultrastructural lesions of the mitochondria and brush border. In common with other studies in which the disease and control populations are not matched for breed, age, sex, and environment, these comparisons should be interpreted with caution. Comparing biopsies collected at presentation and 6 weeks after starting the dietary trial, mean lamina propria mononuclear cell score and lamina propria densities of eosinophils and mononuclear cells decreased. Dietary therapy also improved ultrastructural lesions of the mitochondria and brush border, eliciting a decrease in intermicrovillar space and an increase in microvillus height.

Conclusions and Clinical Importance

In dogs with diet‐responsiveCE, the remission of clinical signs with dietary therapy is associated with subtle decreases in lamina propria density of eosinophils and mononuclear cells, and resolution of ultrastructural lesions of the enterocyte.
Phase I Clinical Trial of Vinorelbine in Tumor‐Bearing Cats
Authors: Pierro J.A , Mallett C.L. , Saba C.F.
Published: May 2013

Background

Vinorelbine (VRL) has been investigated in dogs, but its use in cats has not been studied.

Hypothesis/Objectives

To determine the maximal tolerated dose (MTD) and dose‐limiting toxicity (DLT) of VRL in tumor‐bearing cats.

Animals

Cats were included in this prospective phase I trial if they had confirmed malignancy, received ≥1 VRL treatment, and had adequate follow‐up. Previous treatment was acceptable, but concurrent chemotherapy or radiotherapy was not permitted.

Methods

Using a modified phase I design, cats were enrolled in cohorts of 3 at a starting dosage of 9 mg/m2. Cats tolerating the first treatment well were eligible to receive additional VRL treatments at escalating dosages; escalations beyond the perceived MTD were permitted based on individual tolerance. Intended treatment interval was 7 days. Patient histories, physical examinations, and complete blood counts were performed weekly.

Results

Nineteen cats were included. Sixty‐one VRL treatments were administered. Median number of treatments was 2 (range, 1–9). Starting dosages were 9–12 mg/m2. Maximal dosage administered was 15.5 mg/m2. The MTD was 11.5 mg/m2. Acute DLTs were neutropenia, vomiting, and nephrotoxicity. Other notable toxicities were weight loss and anemia.

Conclusions and Clinical Importance

Vinorelbine is tolerated in cats at a weekly interval. Recommended starting dosage is 11.5 mg/m2. Neutropenia was transient, lasting <7 days; vomiting was self‐limiting in most cases. Although VRL‐associated nephrotoxicity has not been reported, potential attribution of this toxicity to VRL must not be discounted. Further investigation of the efficacy of VRL in feline malignancies is warranted.
Effect of body weight on the pharmacokinetics of flunixin meglumine in miniature horses and quarter horses
Authors: Lee C. D. , Maxwell L. K.
Published: May 2013

In most species, large variations in body size necessitate dose adjustments based on an allometric function of body weight. Despite the substantial disparity in body size between miniature horses and light‐breed horses, there are no studies investigating appropriate dosing of any veterinary drug in miniature horses. The purpose of this study was to determine whether miniature horses should receive a different dosage of flunixin meglumine than that used typically in light‐breed horses. A standard dose of flunixin meglumine was administered intravenously to eight horses of each breed, and three‐compartmental analysis was used to compare pharmacokinetic parameters between breed groups. The total body clearance of flunixin was 0.97 ± 0.30 mL/min/kg in miniature horses and 1.04 ± 0.27 mL/min/kg in quarter horses. There were no significant differences between miniature horses and quarter horses in total body clearance, the terminal elimination rate, area under the plasma concentration versus time curve, apparent volume of distribution at steady‐state or the volume of the central compartment for flunixin (P > 0.05). Therefore, flunixin meglumine may be administered to miniature horses at the same dosage as is used in light‐breed horses.
Axonal expression of sodium channels and neuropathology of the plaques in multiple sclerosis
Authors: Bouafia Adel , Golmard Jean‐Louis , Thuries Valerie , Sazdovitch Veronique , Hauw Jean Jacques , Fontaine Betrand , Seilhean Danielle
Published: May 2013

Aims

Although demyelination is an important cause of neurological deficits in multiple sclerosis (MS), recently axonal pathology and concomitant involvement of sodium channels (Nav) became a focus of major interest. Studies in experimental autoimmune encephalomyelitis (EAE) and MS have shown diffuse expression of Nav1.6 and Nav1.2 along demyelinated axons. However, the relation between this expression by the axon and its environment is not yet known. The aim of this exploratory study was to identify the neuropathological characteristics of the plaque associated with the changes of sodium channel axonal expression.

Methods

We analysed by immunohistochemistry the expression of Nav1.6 and Nav1.2 along demyelinated axons in 64 plaques from 12 MS cases. To characterize the plaques, we used Luxol fast blue staining and immunohistochemistry for myelin basic protein, microglia/macrophages, T and B cells, reactive astrocytes and axonal lesions performed on sections of formalin‐fixed, paraffin‐embedded tissue.

Results

The presence of diffuse axonal expression of Nav1.6 was equally distributed between active demyelinating and inactive not demyelinating plaques based on presence or absence of myelin laden macrophages respectively. However, presence of diffuse axonal expression of Nav1.6 was more frequent within plaques with T cells infiltrate and microglial hyperplasia. On the other hand, Nav1.2 diffuse axonal expression seemed to be independent of the neuropathological environment of the plaque.

Conclusions

The cellular environment of the axon influences the differential expression of Nav channels. A better understanding of the influence of the inflammation on sodium channels mediated axonal degeneration could offer therapeutic perspectives.
A Comparison of Steep and Shallow Needle Trajectories in Blind Axillary Vein Puncture
Authors: JIANG MENG , GONG XIN‐RONG , ZHOU SHENG‐HENG , PU JUN , MAO JIA‐LIANG , HE BEN
Published: May 2013

Background

Previously developed techniques for pacemaker lead introduction usually require some form of image guidance to facilitate the axillary vein puncture process. The existing blind vein puncture methods have not gained widespread acceptance. We aimed to investigate whether our blind vein puncture approach is effective and safe.

Methods

We compared the patient characteristics and clinical outcomes of 600 consecutive patients who underwent different blind axillary vein puncture procedures. In group I, a steep needle puncture method was used, whereas in group II a shallow needle puncture technique was used.

Results

The shallow needle puncture method was associated with a higher success rate than the steep needle puncture method (94% vs 54%, P < 0.00001). The shallow needle puncture method was also associated with a much shorter puncture and lead insertion time (7 ± 2 minutes vs 10 ± 3 minutes, P = 0.02).

Conclusion

Our shallow needle puncture technique does not require any extra equipment. In addition, this method is effective and safe and may be used as the initial attempt for venous access during pacemaker implantation.
DNA repair variants, indoor tanning, and risk of melanoma
Authors: Torres Salina M. , Luo Li , Lilyquist Jenna , Stidley Christine A. , Flores Kristina , White Kirsten A. M. , Erdei Esther , Gonzales Melissa , Paine Susan , Vogel Rachel I. , Lazovich DeAnn , Berwick Marianne
Published: May 2013

Although ultraviolet radiation (UV) exposure from indoor tanning has been linked to an increased risk of melanoma, the role of DNA repair genes in this process is unknown. We evaluated the association of 92 single nucleotide polymorphisms (SNPs) in 20 DNA repair genes with the risk of melanoma and indoor tanning among 929 patients with melanoma and 817 controls from the Minnesota Skin Health Study. Significant associations with melanoma risk were identified for SNPs in ERCC4, ERCC6, RFC1, XPC, MGMT, and FBRSL1 genes; with a cutoff of P < 0.05. ERCC6 and FBRSL1 gene variants and haplotypes interacted with indoor tanning. However, none of the 92 SNPs tested met the correction criteria for multiple comparisons. This study, based on an a priori interest in investigating the role of DNA repair capacity using variants in base excision and nucleotide excision repair, identified several genes that may play a role in resolving UV‐induced DNA damage.
Interaction of small RNA–8105 and the intron of IbMYB1 RNA regulates IbMYB1 family genes through secondary siRNAs and DNA methylation after wounding
Authors: Lin Jeng‐Shane , Lin Chih‐Ching , Li Yu‐Chi , Wu Ming‐Tsung , Tsai Mong‐Hsun , Hsing Yue‐Ie C. , Jeng Shih‐Tong
Published: May 2013

Small RNAs (sRNAs) play important roles in plants under stress conditions. However, limited research has been performed on the sRNAs involved in plant wound responses. In the present study, a novel wounding‐induced sRNA, sRNA8105, was identified in sweet potato (Ipomoea batatas cv. Tainung 57) using microarray analysis. It was found that expression of sRNA8105 increased after mechanical wounding. Furthermore, Dicer‐like 1 (DCL1) is required for the sRNA8105 precursor (pre‐sRNA8105) to generate 22 and 24 nt mature sRNA8105. sRNA8105 targeted the first intron of IbMYB1 (MYB domain protein 1) before RNA splicing, and mediated RNA cleavage and DNA methylation of IbMYB1. The interaction between sRNA8105 and IbMYB1 was confirmed by cleavage site mapping, agro‐infiltration analyses, and use of a transgenic sweet potato over‐expressing pre‐sRNA8105 gene. Induction of IbMYB1‐siRNA was observed in the wild‐type upon wounding and in transgenic sweet potato over‐expressing pre‐sRNA8105 gene without wounding, resulting in decreased expression of the whole IbMYB1 gene family, i.e. IbMYB1 and the IbMYB2 genes, and thus directing metabolic flux toward biosynthesis of lignin in the phenylpropanoid pathway. In conclusion, sRNA8105 induced by wounding binds to the first intron of IbMYB1 RNA to methylate IbMYB1, cleave IbMYB1 RNA, and trigger production of secondary siRNAs, further repressing the expression of the IbMYB1 family genes and regulating the phenylpropanoid pathway.
Performance of a clinical prediction score for thrombotic thrombocytopenic purpura in an independent cohort
Authors: Bentley M. J. , Wilson A. R. , Rodgers G. M.
Published: May 2013

Background and Objectives

Idiopathic thrombotic thrombocytopenic purpura (TTP) is a rare, clinically diagnosed disorder characterized by widespread intravascular platelet thrombosis. The pathophysiology involves acquired deficiency of ADAMTS13 (A disintegrin and metalloprotease with thrombospondin type 1 repeats), the enzyme responsible for cleavage of high molecular weight vonWillebrand factor multimers. Disease mortality is high, although prompt treatment with plasma exchange is generally effective. A readily available and highly reliable method of identifying ADAMTS13‐deficient patients for appropriate plasma exchange is therefore of interest.

Materials and Methods

Our initial study involved the assessment of multiple clinical and laboratory variables in patients with clinically suspected TTP for whom ADAMTS13 assay was performed. Five variables were found to be of significant predictive power. This enabled the development of a point‐based scoring system to efficiently determine the likelihood of TTP and response to plasma exchange in a given patient. This current study involved a separate validation cohort of patients with clinically suspected TTP who underwent ADAMTS13 testing within two large healthcare systems in Utah between 2009 and 2011. The previously derived score was applied to this cohort and its performance was analysed. Additionally, the original and validation cohorts were combined to revisit the predictive power of individual variables and the five‐variable prediction score.

Results

A total of 84 (11 paediatric cases excluded) patients comprised the validation population. The percentage of TTP diagnoses in this group (10%) was identical to that in the initial cohort. Using an ADAMTS13 activity of <10% of normal, our original score correctly predicted or excluded severe ADAMTS13 deficiency in all patients in the second cohort when data for all variables was available. Individual variables retained predictive power and the performance of a three‐variable parsimonious model, as well as the ultimate diagnoses for patients in the second cohort are described.

Conclusion

This work confirms the predictive power of a simple point‐based score to exclude TTP as evidenced by severe ADAMTS13 deficiency in appropriately selected patients. It may enable clinicians to rapidly begin plasma exchange or to pursue an alternative cause of thrombotic microangiopathy.
Potential Animal and Environmental Sources of Q Fever Infection for Humans in Queensland
Authors: Tozer S. J. , Lambert S. B. , Strong C. L. , Field H. E. , Sloots T. P. , Nissen M. D.
Published: May 2013

Q fever is a vaccine‐preventable disease; despite this, high annual notification numbers are still recorded in Australia. We have previously shown seroprevalence in Queensland metropolitan regions is approaching that of rural areas. This study investigated the presence of nucleic acid from Coxiella burnetii, the agent responsible for Q fever, in a number of animal and environmental samples collected throughout Queensland, to identify potential sources of human infection. Samples were collected from 129 geographical locations and included urine, faeces and whole blood from 22 different animal species; 45 ticks were removed from two species, canines and possums; 151 soil samples; 72 atmospheric dust samples collected from two locations and 50 dust swabs collected from domestic vacuum cleaners. PCR testing was performed targeting the IS1111 and COM1 genes for the specific detection of C. burnetii DNA. There were 85 detections from 1318 animal samples, giving a detection rate for each sample type ranging from 2.1 to 6.8%. Equine samples produced a detection rate of 11.9%, whilst feline and canine samples showed detection rates of 7.8% and 5.2%, respectively. Native animals had varying detection rates: pooled urines from flying foxes had 7.8%, whilst koalas had 5.1%, and 6.7% of ticks screened were positive. The soil and dust samples showed the presence of C. burnetii DNA ranging from 2.0 to 6.9%, respectively. These data show that specimens from a variety of animal species and the general environment provide a number of potential sources for C. burnetii infections of humans living in Queensland. These previously unrecognized sources may account for the high seroprevalence rates seen in putative low‐risk communities, including Q fever patients with no direct animal contact and those subjects living in a low‐risk urban environment.
Cryptic diversity in Brevipalpus mites (Tenuipalpidae)
Authors: Navia Denise , Mendonça Renata S. , Ferragut Francisco , Miranda Letícia C. , Trincado Roberto C. , Michaux Johan , Navajas Maria
Published: May 2013

Defining the taxonomic identity of organisms is a prerequisite for their study, and in the case of economically important species, misidentification may lead to the application of inappropriate prevention and control strategies. Flat mites of the Brevipalpus genus include several crop pests and the systematics of these mites represents a challenge for acarologists. Many of the most economically important Brevipalpus species have repeatedly been inaccurately identified. Such problematic classification has been attributed to the likely occurrence of cryptic species in the genus. In this study, we used an integrative approach that combined molecular analyses, including sequence‐based species delimitation, with detailed morphological identification using traits that have recently showed to be taxonomically informative. Sequences of mitochondrial cytochrome c oxidase subunit I (COI) were obtained from individuals collected from host plants belonging to 14 genera and 13 families across 29 locations in the Americas (Brazil, Chile, USA). The phylogenetic analyses included previously published Brevipalpus sequences from GenBank, and the final data set was classified into 44 haplotypes. Six putative species were recognised by COI‐based species delimitation analysis, and morphological evidence supported each of these species. The integrative approach revealed the occurrence of cryptic species in the Brevipalpus genus and contributed to the clarification of previously noted incongruences. The results presented here allow for the evaluation of taxonomic characteristics in a phylogenetic context and indicate new characters for the differentiation of Brevipalpus species. In addition, Brevipalpus incognitus n. sp. Ferragut & Navia, a cryptic species detected in this study, is described based on morphological and molecular traits. Implications of the advances in Brevipalpus systematics presented herein with respect to pest management are briefly discussed.
Pulmonary vascular mechanics: important contributors to the increased right ventricular afterload of pulmonary hypertension
Authors: Wang Zhijie , Chesler Naomi C.
Published: May 2013

New Findings

What is the topic of this review?

This article reviews pulmonary vascular and right ventricular (RV) changes due to hypoxic pulmonary hypertension (HPH), which is a type of pulmonary hypertension (PH) found clinically and has been widely used to induce PH in animal models. As research into clinical PH progression broadens to include RV as well as pulmonary vascular remodelling, an improved understanding of the effects of HPH on the RV is required.

What advances does it highlight?

This article highlights the moderate, adaptive and reversible nature of RV and pulmonary vascular remodelling in HPH. Moreover, we show that increased haematocrit in HPH contributes significantly to RV overload, which warrants additional attention.

Chronic hypoxia causes pulmonary vasoconstriction and vascular remodelling, which lead to hypoxic pulmonary hypertension (HPH). Hypoxic pulmonary hypertension is associated with living at high altitudes and is a complication of many lung diseases, including chronic obstructive pulmonary disease, cystic fibrosis and obstructive sleep apnoea. Pulmonary vascular changes that occur with HPH include stiffening and narrowing of the pulmonary arteries that appear to involve all vascular cell types and sublayers of the arterial wall. Right ventricular (RV) changes that occur with HPH include RV hypertrophy and RV fibrosis, often with preserved systolic and diastolic function and ventricular–vascular coupling efficiency. Both vascular stiffening and vascular narrowing are important contributors to RV afterload via increases in oscillatory and steady ventricular work, respectively. The increased blood viscosity that occurs in HPH can be dramatic and is another important contributor to RV afterload. However, the viscosity, vascular mechanics and ventricular changes that occur with HPH are all reversible. Furthermore, even with continued hypoxia the vascular remodelling does not progress to the obliterative, plexiform lesions that are seen clinically in severe pulmonary hypertension. In animal models, the RV changes appear adaptive, not maladaptive. In summary, HPH‐induced vascular mechanical changes affect ventricular function, but both are adaptive and reversible, which differentiates HPH from severe pulmonary hypertension. The mechanisms of adaptation and reversibility may provide useful insight into therapeutic targets for the clinical disease state.
Effect of bias application to plasma density in weakly magnetized inductively coupled plasma
Authors: Kim Hyuk , Lee Woohyun , Park Wanjae , Whang Ki-Woong
Published: May 2013

Independent control of the ion flux and energy can be achieved in a dual frequency inductively coupled plasma (ICP) system. Typically, the plasma density is controlled by the high-frequency antenna radio-frequency (RF) power and the ion energy is controlled by the low-frequency bias RF power. Increasing the bias power has been known to cause a decrease in the plasma density in capacitively coupled discharge systems as well as in ICP systems. However, an applied axial magnetic field was found to sustain or increase the plasma density as bias power is increased. Measurements show higher electron temperatures but lower plasma densities are obtained in ordinary ICP systems than in magnetized ICP systems under the same neutral gas pressure and RF power levels. Explanations for the difference in the behavior of plasma density with increasing bias power are given in terms of the difference in the heating mechanism in ordinary unmagnetized and magnetized ICP systems.
Fabrication of metal roller mold with submicrometer feature size using contact printing photolithography technique
Authors: Huang Kuo-Feng , Lee Yung-Chun
Published: May 2013

This paper presents an innovative approach for directly forming surface microstructures at submicrometer scale on the cylindrical surface of a metal roller. This roller can then serve as a roller mold in roller imprinting processes for large-area micro/nanofabrication. In the proposed approach, a novel contact printing method is used to transfer a patterned metal film from a planar soft mold to a thin photoresist (PR) layer coated on the roller surface. The pattern definition capability can easily reach submicrometer scale over a large patterning area. Subsequent ultraviolet light exposure and PR developing processes then form a layer of patterned PR microstructures on the cylindrical surface. Finally, patterned microfeatures are directly formed on the roller's surface by an additive (metal deposition) approach. The overall system design, experimental procedures, and experimental results are systematically discussed.
Pliocene Warmth, Polar Amplification, and Stepped Pleistocene Cooling Recorded in NE Arctic Russia
Authors: Brigham-Grette Julie , Melles Martin , Minyuk Pavel , Andreev Andrei , Tarasov Pavel , DeConto Robert , Koenig Sebastian , Nowaczyk Norbert , Wennrich Volker , Rosén Peter , Haltia Eeva , Cook Tim , Gebhardt Catalina , Meyer-Jacob Carsten , Snyder Jeff , Herzschuh Ulrike
Published: May 2013

From Russia with Lovely Data

Climate and the atmospheric concentration of CO
2
are closely linked.

Brigham-Grette
et al.

(p.
1421
, published online 9 May) present data from Lake El'gygytgyn, in northeast Arctic Russia, that shows how climate varied between 3.6 and 2.2 million years ago, an important interval in the global cooling trend that accelerated rapidly at the end of the Miocene. Summer temperatures were about 10°C warmer than today, even though the concentration of atmospheric CO
2
was similar.
Clarifying the Dominant Sources and Mechanisms of Cirrus Cloud Formation
Authors: Cziczo Daniel J. , Froyd Karl D. , Hoose Corinna , Jensen Eric J. , Diao Minghui , Zondlo Mark A. , Smith Jessica B. , Twohy Cynthia H. , Murphy Daniel M.
Published: May 2013

Dusty Origins

The formation of cirrus clouds begins with the production of ice nuclei, on which water vapor then condenses.

Cziczo
et al.

(p.
1320
, published online 9 May) determined the kinds of particles on which cirrus ice crystals form by sublimating samples collected by research aircraft and analyzing the chemical and physical properties of the residual seeds. Most of the seed particles were either mineral dust or metallic.
The Human Malaria Parasite
Pfs47
Gene Mediates Evasion of the Mosquito Immune System
Authors: Molina-Cruz Alvaro , Garver Lindsey S. , Alabaster Amy , Bangiolo Lois , Haile Ashley , Winikor Jared , Ortega Corrie , van Schaijk Ben C. L. , Sauerwein Robert W. , Taylor-Salmon Emma , Barillas-Mury Carolina
Published: May 2013

Malaria Cloak and Dagger

Mosquitoes have a complex immune system capable of effective antiparasite responses; however, malaria transmission is still highly efficient.

Molina-Cruz
et al.

(p.
984
, published online 9 May; see the Perspective by

Philip and Waters

) show that
Plasmodium falciparum
has a gene product,
Pfs47
, that makes the parasite's ookinetes “invisible” to the mosquito immune system. Disruption of this mechanism could potentially be used to block malaria transmission.
GPR15-Mediated Homing Controls Immune Homeostasis in the Large Intestine Mucosa
Authors: Kim Sangwon V. , Xiang Wenkai V. , Kwak Changsoo , Yang Yi , Lin Xiyao W. , Ota Mitsuhiko , Sarpel Umut , Rifkin Daniel B. , Xu Ruliang , Littman Dan R.
Published: May 2013

GPR15 Gets T
regs
to Guard the Gut

The large intestine is the site that is typically most inflamed in Crohn's disease and ulcerative colitis, which are thought to result when the immune system is not able to keep the peace with trillions of resident gut microbes. The immune system does this by recruiting specific cell populations, like regulatory T cells (T
regs
), to the gut.

Kim
et al.

(p.
1456
, published online 9 May) now suggest that the orphan G protein–coupled receptor GPR15 is expressed by T
regs
and required for T
reg
homing to the large intestine in mice.
Structure of Parkin Reveals Mechanisms for Ubiquitin Ligase Activation
Authors: Trempe Jean-François , Sauvé Véronique , Grenier Karl , Seirafi Marjan , Tang Matthew Y. , Ménade Marie , Al-Abdul-Wahid Sameer , Krett Jonathan , Wong Kathy , Kozlov Guennadi , Nagar Bhushan , Fon Edward A. , Gehring Kalle
Published: May 2013

Parkin Enhanced?

Inactivation of parkin, an E3 ubiquitin ligase, is responsible for a familial form of Parkinson's disease and may be involved in sporadic forms as well.

Trempe
et al.

(p.
1451
, published online 9 May) present the crystal structure of full-length parkin in an autoinhibited configuration. Guided by the structure, mutations were designed that activated parkin both in vitro and in cells. Because parkin is neuroprotective, the structure provides a framework for enhancing parkin function as a therapeutic strategy in Parkinson's disease.
Use of Agent-Based Modeling To Explore the Mechanisms of Intracellular Phosphorus Heterogeneity in Cultured Phytoplankton
Authors: Fredrick Neil D. , Berges John A. , Twining Benjamin S. , Nuï¿½ez-Milland Daliangelis , Hellweger Ferdi L.
Published: May 2013

There can be significant intraspecific individual-level heterogeneity in the intracellular P of phytoplankton, which can affect the population-level growth rate. Several mechanisms can create this heterogeneity, including phenotypic variability in various physiological functions (e.g., nutrient uptake rate). Here, we use modeling to explore the contribution of various mechanisms to the heterogeneity in phytoplankton grown in a laboratory culture. An agent-based model simulates individual cells and their intracellular P. Heterogeneity is introduced by randomizing parameters (e.g., maximum uptake rate) of daughter cells at division. The model was calibrated to observations of the P quota of individual cells of the centric diatom
Thalassiosira pseudonana
, which were obtained using synchrotron X-ray fluorescence (SXRF). A number of simulations, with individual mechanisms of heterogeneity turned off, then were performed. Comparison of the coefficient of variation (CV) of these and the baseline simulation (i.e., all mechanisms turned on) provides an estimate of the relative contribution of these mechanisms. The results show that the mechanism with the largest contribution to variability is the parameter characterizing the maximum intracellular P, which, when removed, results in a CV of 0.21 compared to a CV of 0.37 with all mechanisms turned on. This suggests that nutrient/element storage capabilities/mechanisms are important determinants of intrapopulation heterogeneity.
ProP Is Required for the Survival of Desiccated Salmonella enterica Serovar Typhimurium Cells on a Stainless Steel Surface
Authors: Finn Sarah , Hï¿½ndler Kristian , Condell Orla , Colgan Aoife , Cooney Shane , McClure Peter , Amï¿½zquita Alï¿½jandro , Hinton Jay C. D. , Fanning Sï¿½amus
Published: May 2013

Consumers trust commercial food production to be safe, and it is important to strive to improve food safety at every level. Several outbreaks of food-borne disease have been caused by
Salmonella
strains associated with dried food. Currently we do not know the mechanisms used by
Salmonella enterica
serovar Typhimurium to survive in desiccated environments. The aim of this study was to discover the responses of
S
. Typhimurium ST4/74 at the transcriptional level to desiccation on a stainless steel surface and to subsequent rehydration. Bacterial cells were dried onto the same steel surfaces used during the production of dry foods, and RNA was recovered for transcriptomic analysis. Subsequently, dried cells were rehydrated and were again used for transcriptomic analysis. A total of 266 genes were differentially expressed under desiccation stress compared with a static broth culture. The osmoprotectant transporters
proP
,
proU
, and
osmU
(STM1491 to STM1494) were highly upregulated by drying. Deletion of any one of these transport systems resulted in a reduction in the long-term viability of
S
. Typhimurium on a stainless steel food contact surface. The
proP
gene was critical for survival;
proP
deletion mutants could not survive desiccation for long periods and were undetectable after 4 weeks. Following rehydration, 138 genes were differentially expressed, with upregulation observed for genes such as
proP
,
proU
, and the phosphate transport genes (
pstACS
). In time, this knowledge should prove valuable for understanding the underlying mechanisms involved in pathogen survival and should lead to improved methods for control to ensure the safety of intermediate- and low-moisture foods.