bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecological relevance of laboratory determined temperature limits: colonization potential, biogeography and resilience of Antarctic invertebrates to environmental change
Authors: BARNES D. K. A. , PECK L. S. , MORLEY S. A.
Published: January 2010

The relevance of laboratory experiments in predicting effects of climate change has been questioned, especially in Antarctica where sea temperatures are remarkably stable. Laboratory studies of Southern Ocean marine animal capacities to survive increasing temperature mainly utilize rapid temperature elevations, 100 ×–10 000 × faster than sea temperature is predicted to rise. However, due to small‐scale temperature fluctuations these studies may be crucial for understanding colonization patterns and predicting survival particularly through interactions between thermal tolerance and migration. The colonization of disjunct shelves around Antarctica by larvae or adult drift requires crossing or exposure to, rapid temperature changes of up to 2–4 °C over days to weeks. Analyses of responses to warming at varying rates of temperature change in the laboratory allow better predictions of the potential species have for colonizing disjunct shelf areas (such as the Scotia Arc). Inhabiting greater diversities of localities increases the geographic and thermal range species experience. We suggest a strong link between short‐term temperature tolerance, environmental range and prospects for surviving changing environments.
Adaptation to host plants may prevent rapid insect responses to climate change
Authors: PELINI SHANNON L. , KEPPEL JESSICA A. , KELLEY ANN E. , HELLMANN JESSICA. J.
Published: January 2010

We must consider the role of multitrophic interactions when examining species' responses to climate change. Many plant species, particularly trees, are limited in their ability to shift their geographic ranges quickly under climate change. Consequently, for herbivorous insects, geographic mosaics of host plant specialization could prohibit range shifts and adaptation when insects become separated from suitable host plants. In this study, we examined larval growth and survival of an oak specialist butterfly (Erynnis propertius) on different oaks (Quercus spp.) that occur across its range to determine if individuals can switch host plants if they move into new areas under climate change. Individuals from Oregon and northern California, USA that feed on Q. garryana and Q. kelloggii in the field experienced increased mortality on Q. agrifolia, a southern species with low nutrient content. In contrast, populations from southern California that normally feed on Q. agrifolia performed well on Q. agrifolia and Q. garryana and poorly on the northern, high elevation Q. kelloggii. Therefore, colonization of southern E. propertius in higher elevations and some northern locales may be prohibited under climate change but latitudinal shifts to Q. garryana may be possible. Where shifts are precluded due to maladaptation to hosts, populations may not accrue warm‐adapted genotypes. Our study suggests that, when interacting species experience asynchronous range shifts, historical local adaptation may preclude populations from colonizing new locales under climate change.
Developmental reprogramming of reproductive and metabolic dysfunction in sheep: native steroids vs. environmental steroid receptor modulators
Authors: Padmanabhan V. , Sarma H. N. , Savabieasfahani M. , Steckler T. L. , Veiga‐Lopez A.
Published: January 2010

The inappropriate programming of developing organ systems by exposure to excess native or environmental steroids, particularly the contamination of our environment and our food sources with synthetic endocrine disrupting chemicals that can interact with steroid receptors, is a major concern. Studies with native steroids have found that in utero exposure of sheep to excess testosterone, an oestrogen precursor, results in low birth weight offspring and leads to an array of adult reproductive/metabolic deficits manifested as cycle defects, functional hyperandrogenism, neuroendocrine/ovarian defects, insulin resistance and hypertension. Furthermore, the severity of reproductive dysfunction is amplified by excess postnatal weight gain. The constellation of adult reproductive and metabolic dysfunction in prenatal testosterone‐treated sheep is similar to features seen in women with polycystic ovary syndrome. Prenatal dihydrotestosterone treatment failed to result in similar phenotype suggesting that many effects of prenatal testosterone excess are likely facilitated via aromatization to oestradiol. Similarly, exposure to environmental steroid imposters such as bisphenol A (BPA) and methoxychlor (MXC) from days 30 to 90 of gestation had long‐term but differential effects. Exposure of sheep to BPA, which resulted in maternal levels of 30–50 ng/mL BPA, culminated in low birth weight offspring. These female offspring were hypergonadotropic during early postnatal life and characterized by severely dampened preovulatory LH surges. Prenatal MXC‐treated females had normal birth weight and manifested delayed but normal amplitude LH surges. Importantly, the effects of BPA were evident at levels, which approximated twice the highest levels found in human maternal circulation of industrialized nations. These findings provide evidence in support of developmental origin of adult reproductive and metabolic diseases and highlight the risk posed by exposure to environmental endocrine disrupting chemicals.
Ecophysiological differences between genetic lineages facilitate the invasion of non‐native Phragmites australis in North American Atlantic coast wetlands
Authors: Mozdzer Thomas J. , Zieman Joseph C.
Published: January 2010

1. Over the last century, native Phragmites australis lineages have been almost completely replaced along the North American Atlantic coast by an aggressive lineage originating from Eurasia. Understanding the mechanisms that facilitate biological invasions is critical to better understand what makes an invasive species successful.

2. Our objective was to determine what makes the introduced lineage so successful in the study area by specifically investigating if morphological and ecophysiological differences exist between native and introduced genetic lineages of P. australis. We hypothesized a priori that due to phenotypic differences and differences in plant nitrogen (N) content between lineages, the introduced lineage would have a greater photosynthetic potential.

3. In situ ecophysiological and morphological data were collected for 2 years in a mid‐Atlantic tidal marsh and in a glasshouse experiment. We measured photosynthetic parameters (Amax, water use efficiency, stomatal conductance) using infrared gas analysis, in conjunction with ecophysiological and morphological parameters [specific leaf area (SLA), leaf area, chlorophyll content, N content].

4. Introduced P. australis maintained 51% greater rates of photosynthesis and up to 100% greater rates of stomatal conductance which are magnified by its 38–83% greater photosynthetic canopy compared to the native type. The introduced lineage also had a significantly greater SLA and N content. Glasshouse‐grown plants and naturally occurring populations demonstrated similar trends in ecophysiological characteristics, verifying the heritability of these differences. These ecophysiological differences, when combined with an extended growing season, provide the mechanism to explain the success of introduced P. australis in North America.

5. Our findings suggest the native type is a low‐nutrient specialist, with a more efficient photosynthetic mechanisms and lower N demand, whereas the introduced type requires nearly four times more N than the native type to be an effective competitor.

6. Synthesis. Our study is the first to combine field and laboratory data to explain a biological invasion attributed to ecophysiological differences between genetic lineages. Our data corroborates earlier work suggesting anthropogenic modification of wetland environments has provided the state change necessary for the success of introduced P. australis. Finally, our results suggest that genotypic differences within species merit further investigations, especially when related to biological invasions.
Coagulation disorders in patients with severe leptospirosis are associated with severe bleeding and mortality
Authors: Wagenaar J. F. P. , Goris M. G. A. , Partiningrum D. L. , Isbandrio B. , Hartskeerl R. A. , Brandjes D. P. M. , Meijers J. C. M. , Gasem M. H. , Van Gorp E. C. M.
Published: January 2010

Objective  To determine the involvement of coagulation in bleeding and poor outcome in patients with severe leptospirosis.

Methods  In a prospective study, parameters of the coagulation system were measured on admission and during follow‐up in 52 consecutive patients with severe leptospirosis.

Results  All patients showed coagulation disorders, such as prolonged prothrombin time (PT) and activated partial thromboplastin time, marked procoagulant activity [thrombin–antithrombin (TAT) complexes, prothrombin fragment 1+2, D‐dimer], reduced levels of anticoagulant markers (protein C, antithrombin) and increased (anti‐) fibrinolytic activity [plasmin–antiplasmin (PAP) complexes, plasminogen activator inhibitor‐1]. These disorders were more pronounced in patients who died eventually. PT prolongation was associated with mortality (OR 1.4, 95% CI: 1.0–1.8, P = 0.04). Bleeding occurred in 31 subjects (60%). Of these, 24 had mild bleeding and seven had severe haemorrhages. Thrombocytopenia (platelets ≤100 × 109/l) was significantly associated with clinical bleeding (OR 4.6, 95% CI: 1.3–16). A subanalysis of patients with and without severe bleeding revealed a more pronounced imbalance of the coagulation system in patients with severe bleeding, as reflected by a significant association with PT (OR 1.4, 95% CI: 1.0–1.8, P = 0.05) and the TAT/PAP ratio (OR 1.3, 95% CI: 1.0–1.6, P = 0.05), which is an indicator of the balance between coagulation and fibrinolysis. Overt disseminated intravascular coagulation (DIC) was found in 10 (22%) of the 46 patients for whom the score could be calculated. There was no significant association between DIC scores, bleeding diathesis or poor outcome.

Conclusion  The coagulation system was strongly activated in patients with leptospirosis. This was more pronounced in the deceased and in patients with severe bleeding than in than the survivors and in those without severe bleeding.
Association between birth outcomes and aflatoxin B1 biomarker blood levels in pregnant women in Kumasi, Ghana
Authors: Shuaib Faisal M. B. , Jolly Pauline E. , Ehiri John E. , Yatich Nelly , Jiang Yi , Funkhouser Ellen , Person Sharina D. , Wilson Craig , Ellis William O. , Wang Jia‐Sheng , Williams Jonathan H.
Published: January 2010

Objective  To investigate the association between birth outcomes and blood levels of aflatoxin B1 (AFB1)‐lysine adduct in pregnant women in Kumasi, Ghana.

Method  A cross‐sectional study of 785 pregnant women attending antenatal clinic was conducted. Aflatoxin B1 (AFB1)‐lysine adduct levels were determined by high performance liquid chromatography (HPLC) on blood taken after delivery. The birth outcomes considered were small for gestation age, low birthweight, preterm delivery and stillbirth. Participants were divided into quartiles based on the distribution of aflatoxin B1‐lysine adducts in pg/mg albumin (‘low’: ≤2.67, ‘moderate’: >2.67 to ≤4.97, ‘high’: >4.97 to ≤11.34, ‘very high’: >11.34). Statistical analysis involved models that included socio‐demographic variables and other potential confounders.

Results  The average AFB1‐lysine adduct level in maternal serum was 10.9 ± 19.00 pg/mg albumin (range = 0.44–268.73 pg/mg). After adjusting for socio‐demographic variables and potential confounding factors, participants in the highest AFB1‐lysine quartile with ‘very high’ AFB1‐lysine level (>11.34 pg/mg) were more likely to have low birthweight babies (OR, 2.09; 95% CI, 1.19–3.68), and showed a trend of increasing risk for low birthweight (Ptrend = 0.007) compared to participants in the lowest quartile.

Conclusion  This study adds to the growing body of evidence that aflatoxins may increase the risk of adverse birth outcomes. The findings have implications for targeted nutritional education of pregnant women in areas with high levels of aflatoxin contamination of foods.
Spatial co‐distribution of neglected tropical diseases in the East African Great Lakes region: revisiting the justification for integrated control
Authors: Clements Archie C. A. , Deville Marie‐Alice , Ndayishimiye Onésime , Brooker Simon , Fenwick Alan
Published: January 2010

Objective  To determine spatial patterns of co‐endemicity of schistosomiasis mansoni and the soil‐transmitted helminths (STHs) Ascaris lumbricoides, Trichuris trichiura and hookworm in the Great Lakes region of East Africa, to help plan integrated neglected tropical disease programmes in this region.

Method  Parasitological surveys were conducted in Uganda, Tanzania, Kenya and Burundi in 28 213 children in 404 schools. Bayesian geostatistical models were used to interpolate prevalence of these infections across the study area. Interpolated prevalence maps were overlaid to determine areas of co‐endemicity.

Results  In the Great Lakes region, prevalence was 18.1% for Schistosoma mansoni, 50.0% for hookworm, 6.8% for A. lumbricoides and 6.8% for T. trichiura. Hookworm infection was ubiquitous, whereas S. mansoni, A. lumbricoides and T. trichiura were highly focal. Most areas were endemic (prevalence ≥10%) or hyperendemic (prevalence ≥50%) for one or more STHs, whereas endemic areas for schistosomiasis mansoni were restricted to foci adjacent large perennial water bodies.

Conclusion  Because of the ubiquity of hookworm, treatment programmes are required for STH throughout the region but efficient schistosomiasis control should only be targeted at limited high‐risk areas. Therefore, integration of schistosomiasis with STH control is only indicated in limited foci in East Africa.
A new format of the CATT test for the detection of Human African Trypanosomiasis, designed for use in peripheral health facilities
Authors: Hasker E. , Mitashi P. , Baelmans R. , Lutumba P. , Jacquet D. , Lejon V. , Kande V. , Declercq J. , Van der Veken W. , Boelaert M.
Published: January 2010

Objectives  To test the reproducibility and thermostability of a new format of the Card‐Agglutination Test for Trypanosomiasis (CATT) test for Human African Trypanosomiasis (HAT), designed for use at primary health care facility level in endemic countries.

Methods  A population of 4217 from highly endemic villages was screened using the existing format of the CATT test (CATT‐R250) on whole blood. All those testing positive (220) and a random sample of negatives (555) were retested in the field with the new format (CATT‐D10). Inter‐format reproducibility was assessed by calculating kappa. All samples testing positive on whole blood with either method were further evaluated in Belgium by CATT titration of serum by two observers, using both old and new format. CATT‐D10 test kits were incubated under four temperature regimens (4, 37, 45 °C and fluctuating) with regular assessments of reactivity over 18 months.

Results  Inter‐format reproducibility of CATT‐D10 vs. CATT‐R250 on whole blood performed by laboratory technicians in the field was excellent with kappa values of 0.83–0.89. Both inter‐ and intra‐format reproducibility assessed by CATT titration were excellent, with 96.5–100% of all differences observed falling within the limits of ±1 titration step. After 18 months, reactivity of test kits incubated under all four temperature regimens was still well above the minimum threshold considered acceptable.

Conclusion  The CATT‐D10 is thermostable and can be used interchangeably with the old format of the CATT test. It is highly suitable for use in peripheral health facilities in HAT‐endemic countries.
GENETIC STUDY: Interaction of SLC6A4 and DRD2 polymorphisms is associated with a history of delirium tremens
Authors: Karpyak Victor M. , Biernacka Joanna M. , Weg Mark W. Vander , Stevens Susanna R. , Cunningham Julie M. , Mrazek David A. , Black John L.
Published: January 2010

Several genetic polymorphisms have been reported to be associated with alcohol withdrawal seizures (AWS) and delirium tremens (DT). To replicate and further explore these findings, we investigated the effects of 12 previously reported candidate genetic variations in two groups of alcohol‐dependent European Americans with a history of withdrawal, which differed according to the presence (n = 112) or absence (n = 92) of AWS and/or DT. Associations of AWS and/or DT with the genomic and clinical characteristics and gene–gene interaction effects were investigated using logistic regression models. None of the polymorphisms were significantly associated with AWS/DT after correction for multiple testing. However, we found a significant interaction effect of the SLC6A4 promoter polymorphism (5‐HTTLPR) and DRD2 exon 8 single nucleotide polymorphism rs6276 on AWS and/or DT history (P = 0.009), which became more significant after adjustment for lifetime maximum number of drinks consumed per 24 hours (P < 0.001). Subsequent analysis revealed an even stronger association of the SLC6A4–DRD2 interaction with DT (P < 0.0001), which remained significant after Bonferroni correction. Results reveal decreased likelihood of DT in alcoholics that carry the DRD2 rs6276 G allele and SLC6A4 LL genotype. This study provides the first evidence to implicate the interaction between serotonin and dopamine neurotransmission in the etiology of DT. Replication is necessary to verify this potentially important finding.
PRECLINICAL STUDY: Mechanisms of respiratory insufficiency induced by methadone overdose in rats
Authors: Chevillard Lucie , Mégarbane Bruno , Baud Frédéric J. , Risède Patricia , Declèves Xavier , Mager Donald , Milan Nathalie , Ricordel Ivan
Published: January 2010

Methadone may cause respiratory depression. We aimed to understand methadone‐related effects on ventilation as well as each opioid‐receptor (OR) role. We studied the respiratory effects of intraperitoneal methadone at 1.5, 5, and 15 mg/kg (corresponding to 80% of the lethal dose‐50%) in rats using arterial blood gases and plethysmography. OR antagonists, including intravenous 10 mg/kg‐naloxonazine at 5 minutes (mu‐OR antagonist), subcutaneous 30 mg/kg‐naloxonazine at 24 hours (mu1‐OR antagonist), 3 mg/kg‐naltrindole at 45 minutes (delta‐OR antagonist) and 5 mg/kg‐Nor‐binaltorphimine at 6 hours (kappa‐OR antagonist) were pre‐administered. Plasma concentrations of methadone enantiomers were measured using high‐performance liquid chromatography coupled to mass‐spectrometry. Methadone dose‐dependent inspiratory time (TI) increase tended to be linear. Respiratory depression was observed only at 15 mg/kg and characterized by an increase in expiratory time (TE) resulting in hypoxemia and respiratory acidosis. Intravenous naloxonazine completely reversed all methadone‐related effects on ventilation, while subcutaneous naloxonazine reduced its effects on pH (P < 0.05), PaCO2(P < 0.01) and TE(P < 0.001) but only partially on TI(P < 0.001). Naltrindole reduced methadone‐related effects on TE(P < 0.001). Nor‐binaltorphimine increased methadone‐related effects on pH and PaO2(P < 0.05) Respiratory effects as a function of plasmaR‐methadone concentrations showed a decrease in PaO2(EC50: 1.14 µg/ml) at lower concentrations than those necessary for PaCO2increase (EC50: 3.35 µg/ml). Similarly, increased TI(EC50: 0.501 µg/ml) was obtained at lower concentrations than those for TE(EC50: 4.83 µg/ml). Methadone‐induced hypoxemia is caused by mu‐ORs and modulated by kappa‐ORs. Additionally, methadone‐induced increase in TEis caused by mu1‐ and delta‐opioid receptors while increase in TIis caused by mu‐ORs.
CLINICAL STUDY/BIOMARKER: Phosphatidylethanol: normalization during detoxification, gender aspects and correlation with other biomarkers and self‐reports
Authors: Wurst Friedrich Martin , Thon Natasha , Aradottir Steina , Hartmann Susanne , Wiesbeck Gerhard Adam , Lesch Otto , Skala Katrin , Wolfersdorf Manfred , Weinmann Wolfgang , Alling Christer
Published: January 2010

Phosphatidylethanol (PEth) is a direct ethanol metabolite, and has recently attracted attention as biomarker of ethanol intake. The aims of the current study are: (1) to characterize the normalization time of PEth in larger samples than previously conducted; (2) to elucidate potential gender differences; and (3) to report the correlation of PEth with other biomarkers and self‐reported alcohol consumption. Fifty‐seven alcohol‐dependent patients (ICD 10 F 10.25; 9 females, 48 males) entering medical detoxification at three study sites were enrolled. The study sample was comprised of 48 males and 9 females, with mean age 43.5. Mean gamma glutamyl transpeptidase (GGT) was 209.61 U/l, average mean corpuscular volume (MCV) was 97.35 fl, mean carbohydrate deficient transferrin (%CDT) was 8.68, and mean total ethanol intake in the last 7 days was 1653 g. PEth was measured in heparinized whole blood with a high‐pressure liquid chromatography method, while GGT, MCV and %CDT were measured using routine methods. PEth levels at day 1 of detoxification ranged between 0.63 and 26.95 µmol/l (6.22 mean, 4.70 median, SD 4.97). There were no false negatives at day 1. Sensitivities for the other biomarkers were 40.4% for MCV, 73.1% for GGT and 69.2% for %CDT, respectively. No gender differences were found for PEth levels at any time point. Our data suggest that PEth is (1) a suitable intermediate term marker of ethanol intake in both sexes; and (2) sensitivity is extraordinary high in alcohol dependent patients. The results add further evidence to the data that suggest that PEth has potential as a candidate for a sensitive and specific biomarker, which reflects longer‐lasting intake of higher amounts of alcohol and seemingly has the above mentioned certain advantages over traditional biomarkers.
PRECLINICAL STUDY: Mice lacking Gad2 show altered behavioral effects of ethanol, flurazepam and gabaxadol
Authors: Blednov Yuri A. , Walker Danielle L. , Iyer Sangeetha V. , Homanics Gregg , Harris Adron R.
Published: January 2010

γ‐Aminobutyric acid (GABA) is synthesized in brain by two isoforms of glutamic acid decarboxylase (Gad), Gad1 and Gad2. Gad1 provides most of the GABA in brain, but Gad2 can be rapidly activated in times of high GABA demand. Mice lackingGad2are viable whereas deletion ofGad1is lethal. We produced null mutant mice forGad2on three different genetic backgrounds: predominantly C57BL/6J and one or two generations of backcrossing to 129S1/SvimJ (129N1, 129N2). We used these mice to determine if actions of alcohol are regulated by synthesis of GABA from this isoform. We also studied behavioral responses to a benzodiazepine (flurazepam) and a GABAA receptor agonist (gabaxadol). Deletion ofGad2increased ethanol palatability and intake and slightly reduced the severity of ethanol‐induced withdrawal, but these effects depended strongly on genetic background. Mutant mice on the 129N2 background showed the above three ethanol behavioral phenotypes, but the C57BL/6J inbred background did not show any of these phenotypes. Effects on ethanol consumption also depended on the test as the mutation did not alter consumption in limited access models. Deletion ofGad2reduced the effect of flurazepam on motor incoordination and increased the effect of extrasynaptic GABAA receptor agonist gabaxadol without changing the duration of loss of righting reflex produced by these drugs. These results are consistent with earlier proposals that deletion ofGad2(on 129N2 background) reduces synaptic GABA but also suggest changes in extrasynaptic receptor function.
Physiological stress links parasites to carotenoid-based colour signals
Authors: Mougeot F. , Martínez-Padilla J. , Bortolotti G. R. , Webster L. M. I. , Piertney S. B.
Published: January 2010

Vertebrates commonly use carotenoid-based traits as social signals. These can reliably advertise current nutritional status and health because carotenoids must be acquired through the diet and their allocation to ornaments is traded-off against other self-maintenance needs. We propose that the coloration more generally reveals an individual’s ability to cope with stressful conditions. We tested this idea by manipulating the nematode parasite infection in free-living red grouse (Lagopus lagopus scoticus) and examining the effects on body mass, carotenoid-based coloration of a main social signal and the amount of corticosterone deposited in feathers grown during the experiment. We show that parasites increase stress and reduce carotenoid-based coloration, and that the impact of parasites on coloration was associated with changes in corticosterone, more than changes in body mass. Carotenoid-based coloration appears linked to physiological stress and could therefore reveal an individual’s ability to cope with stressors.
Trans-generational effects on ageing in a wild bird population
Authors: Bouwhuis S. , Charmantier A. , Verhulst S. , Sheldon B. C.
Published: January 2010

Ageing, long thought to be too infrequent to study effectively in natural populations, has recently been shown to be ubiquitous, even in the wild. A major challenge now is to explain variation in the rates of ageing within populations. Here, using 49 years of data from a population of great tits (Parus major), we show that offspring life-history trajectories vary with maternal age. Offspring hatched from older mothers perform better early in life, but suffer from an earlier onset, and stronger rate, of reproductive senescence later in life. Offspring reproductive lifespan is, however, unaffected by maternal age, and the different life-history trajectories result in a similar fitness payoff, measured as lifetime reproductive success. This study therefore identifies maternal age as a new factor underlying variation in rates of ageing, and, given the delayed trans-generational nature of this effect, poses the question as to proximate mechanisms linking age-effects across generations.
Role of 24‐Epibrassinolide in Wheat Production: Physiological Effects and Uptake
Authors: Janeczko A. , Biesaga‐Kościelniak J. , Oklešt'ková J. , Filek M. , Dziurka M. , Szarek‐Łukaszewska G. , Kościelniak J.
Published: January 2010

Brassinosteroids are plant steroid hormones important for plant growth and development. They include more then 70 compounds. Their physiological effect and possibilities of practical use are still being investigated. In this study, we evaluated the effects of exogenously applied 24‐epibrassinolide, one of the brassinosteroids, on the grain yield and grain chemical composition (carbohydrates, proteins, fats and minerals) of wheat. Moreover, we analysed the presence of brassinosteroids in newly formed wheat grains after exogenous plant treatment with 24‐epibrassinolide. Experiments were performed in a vegetation hall (plants cultivated in pots) and in the field. The tested regulator was applied via 48 h seed soaking (1 mg·dm−3) or spraying plants at the heading stage (0.25 mg·dm−3). 24‐epibrassinolide increased grain yield in plants growing in the field (by about 20 %), but not in plants cultivated in vegetation hall. Grain chemical composition was altered by 24‐epibrassinolide in wheat growing in the vegetation hall; the content of soluble sugars was higher while that of total fats and calcium was lowered, whereas the starch and soluble protein content was not affected. The effect of the hormone was in these cases dependent on the method of its application. As for plants cultivated in the field, the hormone impact on the amount of carbohydrates, proteins, fats and minerals contained in the grains was rather negligible. In wheat grains, the presence of brassinolide, castasterone and 24‐epicastasterone was found. 24‐Epibrassinolide applied exogenously to plants was not accumulated in newly formed grains. Additionally, significance of ethanol as a hormone solvent is discussed.
Discovery and transmission of functional QTL in the pedigree of an elite soybean cultivar Suinong14
Authors: Qin J. , Yang R. Q. , Jiang C. X. , Li W. B. , Li Y. H. , Guan R. X. , Chang R. Z. , Qiu L. J.
Published: January 2010

With 3 figures and 5 tables

In this study, we extended in silico mapping for single trait to analyse data from multiple environments by calculating intraclass correlations and to mapping pleiotropic QTL for multiple traits by defining new statistic to measure the correlation between multiple traits and the marker. Data sets include phenotypes of eight agronomic traits obtained from six different ecologic environments and years, and genotypic information from 477 polymorphic markers on 14 ancestral lines in the pedigree of ‘Suinong14’. With in silico mapping, a total of 39 markers distributed on 14 linkage groups are detected as QTL responsible for eight agronomic traits and 10 QTL are identified as having pleiotropic effects. Tracing transmission of functional QTL in the pedigree indicated that certain QTL, such as Sat_036 on linkage group D1a, Satt182 on linkage group L, and Satt726 on linkage group B2 may be responsible for the contribution of exotic germplasm to the improved cultivars.
Identification of a null allele at the Wx‐A1 locus in durum wheat (Triticum turgidum L. ssp. durum Desf.)
Authors: Vanzetti L.S. , Pflüger L. , Bainotti C.T. , Jensen C. , Helguera M.
Published: January 2010

With 3 figures and 1 table

This work describes a novel null Wx‐A1 allele detected in one cultivar and two breeding lines from a collection of 48 durum wheats from Argentina. The electrophoretic patterns of waxy proteins showed 45 accessions displaying Wx‐A1 and Wx‐B1 proteins and three accessions that lacked the Wx‐A1 protein. Partial sequence of the Wx‐A1 gene obtained from the three lines lacking the Wx‐A1 protein showed a 1‐bp deletion in exon 6 that produces a frameshift and a premature stop codon in the gene sequence. In addition, a PCR‐RFLP marker suitable to detect the null Wx‐A1 allele in segregating populations is described.
Dynamic stimulation evokes spatially focused receptive fields in bat auditory cortex
Authors: Hoffmann Susanne , Schuller Gerd , Firzlaff Uwe
Published: January 2010

Bats can orient and hunt for prey in complete darkness using echolocation. Due to the pulse‐like character of call emission they receive a stroboscopic view of their environment. During target approach, bats adjust their emitted echolocation calls to the specific requirements of the dynamically changing environmental and behavioral context. In addition to changes of the spectro‐temporal call features, the spatial focusing of the beam of the sonar emissions onto the target is a conspicuous feature during target tracking. The neural processes underlying the complex sensory‐motor interactions during target tracking are not well understood. In this study, we used a two‐tone‐pulse paradigm with 81 combinations of inter‐aural intensity differences and six inter‐pulse intervals in a passive hearing task to tackle the question of how transient changes in the azimuthal position of successive sounds are encoded by neurons in the auditory cortex of the bat Phyllostomus discolor. In a population of cortical neurons (11%, 24 of 217), spatial receptive fields were focused to a small region of frontal azimuthal positions during dynamic stimulation with tone‐pulse pairs at short inter‐pulse intervals. The response of these neurons might be important for the behaviorally observed locking of the sonar beam onto a selected target during the later stages of target tracking. Most interestingly, the majority of these neurons (88%, 21 of 24) were located in the posterior dorsal part of the auditory cortex. This cortical subfield might thus be specifically involved in the analysis of dynamic acoustic scenes.
Activation of neurons in the hypothalamic dorsomedial nucleus via hypothalamic projections of the nucleus of the solitary tract following refeeding of fasted rats
Authors: Renner Eva , Szabó‐Meltzer Kinga I. , Puskás Nela , Tóth Zsuzsanna E. , Dobolyi Arpád , Palkovits Miklós
Published: January 2010

We report that satiation evokes neuronal activity in the ventral subdivision of the hypothalamic dorsomedial nucleus (DMH) as indicated by increased c‐fos expression in response to refeeding in fasted rats. The absence of significant Fos activation following food presentation without consumption suggests that satiation but not craving for food elicits the activation of ventral DMH neurons. The distribution pattern of the prolactin‐releasing peptide (PrRP)‐immunoreactive (ir) network showed remarkable correlations with the distribution of activated neurons within the DMH. The PrRP‐ir fibers and terminals were immunolabeled with tyrosine hydroxylase, suggesting their origin in lower brainstem instead of local, hypothalamic PrRP cells. PrRP‐ir fibers arising from neurons of the nucleus of the solitary tract could be followed to the hypothalamus. Unilateral transections of these fibers at pontine and caudal hypothalamic levels resulted in a disappearance of the dense PrRP‐ir network in the ventral DMH while PrRP immunoreactivity was increased in transected fibers caudal to the knife cuts as well as in perikarya of the nucleus of the solitary tract ipsilateral to the transections. In accord with these changes, the number of Fos‐expressing neurons following refeeding declined in the ipsilateral but remained high in the contralateral DMH. However, the Fos response in the ventral DMH was not attenuated following chemical lesion (neonatal monosodium glutamate treatment) of the hypothalamic arcuate nucleus, another possible source of DMH inputs. These findings suggest that PrRP projections from the nucleus of the solitary tract contribute to the activation of ventral DMH neurons during refeeding, possibly by transferring information on cholecystokinin‐mediated satiation.
Asymmetries in long‐term and short‐term plasticity at thalamic and cortical inputs to the amygdala in vivo
Authors: Sigurðsson Torfi , Cain Christopher K. , Doyère Valérie , LeDoux Joseph E.
Published: January 2010

Converging lines of evidence suggest that synaptic plasticity at auditory inputs to the lateral amygdala (LA) is critical for the formation and storage of auditory fear memories. Auditory information reaches the LA from both thalamic and cortical areas, raising the question of whether they make distinct contributions to fear memory storage. Here we address this by comparing the induction of long‐term potentation (LTP) at the two inputs in vivo in anesthetized rats. We first show, using field potential measurements, that different patterns and frequencies of high‐frequency stimulation (HFS) consistently elicit stronger LTP at cortical inputs than at thalamic inputs. Field potential responses elicited during HFS of thalamic inputs were also smaller than responses during HFS of cortical inputs, suggesting less effective postsynaptic depolarization. Pronounced differences in the short‐term plasticity profiles of the two inputs were also observed: whereas cortical inputs displayed paired‐pulse facilitation, thalamic inputs displayed paired‐pulse depression. These differences in short‐ and long‐term plasticity were not due to stronger inhibition at thalamic inputs: although removal of inhibition enhanced responses to HFS, it did not enhance thalamic LTP and left paired‐pulse depression unaffected. These results highlight the divergent nature of short‐ and long‐term plasticity at thalamic and cortical sensory inputs to the LA, pointing to their different roles in the fear learning system.
View‐invariant object recognition ability develops after discrimination, not mere exposure, at several viewing angles
Authors: Yamashita Wakayo , Wang Gang , Tanaka Keiji
Published: January 2010

One usually fails to recognize an unfamiliar object across changes in viewing angle when it has to be discriminated from similar distractor objects. Previous work has demonstrated that after long‐term experience in discriminating among a set of objects seen from the same viewing angle, immediate recognition of the objects across 30–60° changes in viewing angle becomes possible. The capability for view‐invariant object recognition should develop during the within‐viewing‐angle discrimination, which includes two kinds of experience: seeing individual views and discriminating among the objects. The aim of the present study was to determine the relative contribution of each factor to the development of view‐invariant object recognition capability. Monkeys were first extensively trained in a task that required view‐invariant object recognition (Object task) with several sets of objects. The animals were then exposed to a new set of objects over 26 days in one of two preparatory tasks: one in which each object view was seen individually, and a second that required discrimination among the objects at each of four viewing angles. After the preparatory period, we measured the monkeys’ ability to recognize the objects across changes in viewing angle, by introducing the object set to the Object task. Results indicated significant view‐invariant recognition after the second but not first preparatory task. These results suggest that discrimination of objects from distractors at each of several viewing angles is required for the development of view‐invariant recognition of the objects when the distractors are similar to the objects.
Methamphetamine‐induced neuroinflammation and neuronal dysfunction in the mice hippocampus: preventive effect of indomethacin
Authors: Gonçalves Joana , Baptista Sofia , Martins Tânia , Milhazes Nuno , Borges Fernanda , Ribeiro Carlos F. , Malva João O. , Silva Ana P.
Published: January 2010

Methamphetamine (METH) causes irreversible damage to brain cells leading to neurological and psychiatric abnormalities. However, the mechanisms underlying life‐threatening effects of acute METH intoxication remain unclear. Indeed, most of the hypotheses focused on intra‐neuronal events, such as dopamine oxidation, oxidative stress and excitotoxicity. Yet, recent reports suggested that glia may contribute to METH‐induced neuropathology. In the present study, we investigated the hippocampal dysfunction induced by an acute high dose of METH (30 mg/kg; intraperitoneal injection), focusing on the inflammatory process and changes in several neuronal structural proteins. For that, 3‐month‐old male wild‐type C57BL/6J mice were killed at different time‐points post‐METH. We observed that METH caused an inflammatory response characterized by astrocytic and microglia reactivity, and tumor necrosis factor (TNF) system alterations. Indeed, glial fibrillary acidic protein (GFAP) and CD11b immunoreactivity were upregulated, likewise TNF‐α and TNF receptor 1 protein levels. Furthermore, the effect of METH on hippocampal neurons was also investigated, and we observed a downregulation in beta III tubulin expression. To clarify the possible neuronal dysfunction induced by METH, several neuronal proteins were analysed. Syntaxin‐1, calbindin D28k and tau protein levels were downregulated, whereas synaptophysin was upregulated. We also evaluated whether an anti‐inflammatory drug could prevent or diminish METH‐induced neuroinflammation, and we concluded that indomethacin (10 mg/kg; i.p.) prevented METH‐induced glia activation and both TNF system and beta III tubulin alterations. In conclusion, we demonstrated that METH triggers an inflammatory process and leads to neuronal dysfunction in the hippocampus, which can be prevented by an anti‐inflammatory treatment.
Involvement of the 4‐aminopyridine‐sensitive transient A‐type K+ current in macrophage‐induced neuronal injury
Authors: Hu Dehui , Liu Jianuo , Keblesh James , Xiong Huangui
Published: January 2010

Through their capacity to secrete, upon activation, a variety of bioactive molecules, brain macrophages (and resident microglia) play an important role in brain immune and inflammatory responses. To test our hypothesis that activated macrophages induce neuronal injury by enhancing neuronal outward K+ current, we studied the effects of lipopolysaccharide (LPS)‐stimulated human monocyte‐derived macrophage (MDM) on neuronal transient A‐type K+ current (IA) and resultant neuronal injury in primary rat hippocampal neuronal cultures. Bath application of LPS‐stimulated MDM‐conditioned media (MCM+) enhanced neuronal IA in a concentration‐dependent manner. Non‐stimulated MCM (MCM‐) failed to alter IA. The enhancement of neuronal IA was recapitulated in neurons co‐cultured with macrophages. The link of MCM(+)‐induced enhancement of IA to MCM(+)‐associated neuronal injury, as detected by propidium iodide and 4″,6‐diamidino‐2‐phenylindol staining (DAPI) and 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay, was demonstrated by experimental results showing that addition of IA blocker 4‐aminopyridine to the cultures protected hippocampal neurons from MCM(+)‐induced neuronal injury. Further investigation revealed that glutamate was involved in MCM(+)‐induced enhancement of neuronal IA. These results suggest that during brain inflammation macrophages (and microglia) might mediate neuronal injury via enhancement of neuronal IA, and that neuronal Kv channel might be a potential target for the development of therapeutic strategies for some neurodegenerative disorders by which immune and inflammatory responses are believed to be involved in the pathogenesis.
Filopodial protrusions induced by glycoprotein M6a exhibit high motility and aids synapse formation
Authors: Brocco Marcela A. , Fernández María Eugenia , Frasch Alberto C. C.
Published: January 2010

M6a is a neuronal membrane glycoprotein whose expression diminishes during chronic stress. M6a overexpression in rat primary hippocampal neurons induces the formation of filopodial protrusions that could be spine precursors. As the filopodium and spine motility has been associated with synaptogenesis, we analysed the motility of M6a‐induced protrusions by time‐lapse imaging. Our data demonstrate that the motile protrusions formed by the neurons overexpressing M6a were more abundant and moved faster than those formed in control cells. When different putative M6a phosphorylation sites were mutated, the neurons transfected with a mutant lacking intracellular phosphorylation sites bore filopodia, but these protrusions did not move as fast as those formed by cells overexpressing wild‐type M6a. This suggests a role for M6a phosphorylation state in filopodium motility. Furthermore, we show that M6a‐induced protrusions could be stabilized upon contact with presynaptic region. The motility of filopodia contacting or not neurites overexpressing synaptophysin was analysed. We show that the protrusions that apparently contacted synaptophysin‐labeled cells exhibited less motility. The behavior of filopodia from M6a‐overexpressing cells and control cells was alike. Thus, M6a‐induced protrusions may be spine precursors that move to reach presynaptic membrane. We suggest that M6a is a key molecule for spine formation during development.
Neurons in primary motor cortex engaged during action observation
Authors: Dushanova Juliana , Donoghue John
Published: January 2010

Neurons in higher cortical areas appear to become active during action observation, either by mirroring observed actions (termed mirror neurons) or by eliciting mental rehearsal of observed motor acts. We report the existence of neurons in the primary motor cortex (M1), an area that is generally considered to initiate and guide movement performance, responding to viewed actions. Multielectrode recordings in monkeys performing or observing a well‐learned step‐tracking task showed that approximately half of the M1 neurons that were active when monkeys performed the task were also active when they observed the action being performed by a human. These ‘view’ neurons were spatially intermingled with ‘do’ neurons, which are active only during movement performance. Simultaneously recorded ‘view’ neurons comprised two groups: approximately 38% retained the same preferred direction (PD) and timing during performance and viewing, and the remainder (62%) changed their PDs and time lag during viewing as compared with performance. Nevertheless, population activity during viewing was sufficient to predict the direction and trajectory of viewed movements as action unfolded, although less accurately than during performance. ‘View’ neurons became less active and contained poorer representations of action when only subcomponents of the task were being viewed. M1 ‘view’ neurons thus appear to reflect aspects of a learned movement when observed in others, and form part of a broadly engaged set of cortical areas routinely responding to learned behaviors. These findings suggest that viewing a learned action elicits replay of aspects of M1 activity needed to perform the observed action, and could additionally reflect processing related to understanding, learning or mentally rehearsing action.
Schizophrenia‐related endophenotypes in heterozygous neuregulin‐1 ‘knockout’ mice
Authors: O’Tuathaigh C. M. P. , Harte M. , O’Leary C. , O’Sullivan G. J. , Blau C. , Lai D. , Harvey R. P. , Tighe O. , Fagan A. J. , Kerskens C. , Reynolds G. P. , Waddington J. L.
Published: January 2010

Neuregulin‐1 (NRG1) has been shown to play a role in glutamatergic neurotransmission and is a risk gene for schizophrenia, in which there is evidence for hypoglutamatergic function. Sensitivity to the behavioural effects of the psychotomimetic N‐methyl‐d‐aspartate receptor antagonists MK‐801 and phencyclidine (PCP) was examined in mutant mice with heterozygous deletion of NRG1. Social behaviour (sociability, social novelty preference and dyadic interaction), together with exploratory activity, was assessed following acute or subchronic administration of MK‐801 (0.1 and 0.2 mg/kg) or PCP (5 mg/kg). In untreated NRG1 mutants, levels of glutamate, N‐acetylaspartate and GABA were determined using high‐performance liquid chromatography and regional brain volumes were assessed using magnetic resonance imaging at 7T. NRG1 mutants, particularly males, displayed decreased responsivity to the locomotor‐activating effects of acute PCP. Subchronic MK‐801 and PCP disrupted sociability and social novelty preference in mutants and wildtypes and reversed the increase in both exploratory activity and social dominance‐related behaviours observed in vehicle‐treated mutants. No phenotypic differences were demonstrated in N‐acetylaspartate, glutamate or GABA levels. The total ventricular and olfactory bulb volume was decreased in mutants. These data indicate a subtle role for NRG1 in modulating several schizophrenia‐relevant processes including the effects of psychotomimetic N‐methyl‐d‐aspartate receptor antagonists.
Safety of pramlintide added to mealtime insulin in patients with type 1 or type 2 diabetes: a large observational study
Authors: Pencek R. , Roddy T. , Peters Y. , De Young M. B. , Herrmann K. , Meller L. , Nguyen H. , Chen S. , Lutz K.
Published: January 2010

The objective of this Phase 4, open‐label, multicentre, observational study was to fulfil food and drug administration (FDA) postapproval requirement to evaluate in healthcare practices the risk of insulin‐induced severe hypoglycaemia following initiation of pramlintide therapy in N = 1297 patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) with inadequate glycaemic control. The duration of the study was approximately 6 months. During the adjustment period (0–3 months), the incidence and event rate of patient‐ascertained severe hypoglycaemia (PASH) were 4.8% and 0.33 events/patient‐year in patients with T1DM and 2.8% and 0.19 events/patient‐year in patients with T2DM. During the maintenance period (>3–6 months), the incidence and event rate of PASH declined in patients with T1DM or T2DM. This study confirms that in healthcare practices, the risk of insulin‐induced severe hypoglycaemia following the initiation of pramlintide is low in patients with T1DM or T2DM.