bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomedical photoacoustic imaging
Authors: Beard Paul
Published: July 2011

Photoacoustic (PA) imaging, also called optoacoustic imaging, is a new biomedical imaging modality based on the use of laser-generated ultrasound that has emerged over the last decade. It is a hybrid modality, combining the high-contrast and spectroscopic-based specificity of optical imaging with the high spatial resolution of ultrasound imaging. In essence, a PA image can be regarded as an ultrasound image in which the contrast depends not on the mechanical and elastic properties of the tissue, but its optical properties, specifically optical absorption. As a consequence, it offers greater specificity than conventional ultrasound imaging with the ability to detect haemoglobin, lipids, water and other light-absorbing chomophores, but with greater penetration depth than purely optical imaging modalities that rely on ballistic photons. As well as visualizing anatomical structures such as the microvasculature, it can also provide functional information in the form of blood oxygenation, blood flow and temperature. All of this can be achieved over a wide range of length scales from micrometres to centimetres with scalable spatial resolution. These attributes lend PA imaging to a wide variety of applications in clinical medicine, preclinical research and basic biology for studying cancer, cardiovascular disease, abnormalities of the microcirculation and other conditions. With the emergence of a variety of truly compelling
in vivo
images obtained by a number of groups around the world in the last 2–3 years, the technique has come of age and the promise of PA imaging is now beginning to be realized. Recent highlights include the demonstration of whole-body small-animal imaging, the first demonstrations of molecular imaging, the introduction of new microscopy modes and the first steps towards clinical breast imaging being taken as well as a myriad of
in vivo
preclinical imaging studies. In this article, the underlying physical principles of the technique, its practical implementation, and a range of clinical and preclinical applications are reviewed.
Ultrasonic imaging: safety considerations
Authors: Haar Gail ter
Published: July 2011

Modern ultrasound imaging for diagnostic purposes has a wide range of applications. It is used in obstetrics to monitor the progress of pregnancy, in oncology to visualize tumours and their response to treatment, and, in cardiology, contrast-enhanced studies are used to investigate heart function and physiology. An increasing use of diagnostic ultrasound is to provide the first photograph for baby's album—in the form of a souvenir or keepsake scan that might be taken as part of a routine investigation, or during a visit to an independent high-street ‘boutique’. It is therefore important to ensure that any benefit accrued from these applications outweighs any accompanying risk, and to evaluate the existing ultrasound bio-effect and epidemiology literature with this in mind. This review considers the existing laboratory and epidemiological evidence about the safety of diagnostic ultrasound and puts it in the context of current clinical usage.
Nucleic acid-based nanoengineering: novel structures for biomedical applications
Authors: Li Hanying , LaBean Thomas H. , Leong Kam W.
Published: July 2011

Nanoengineering exploits the interactions of materials at the nanometre scale to create functional nanostructures. It relies on the precise organization of nanomaterials to achieve unique functionality. There are no interactions more elegant than those governing nucleic acids via Watson–Crick base-pairing rules. The infinite combinations of DNA/RNA base pairs and their remarkable molecular recognition capability can give rise to interesting nanostructures that are only limited by our imagination. Over the past years, creative assembly of nucleic acids has fashioned a plethora of two-dimensional and three-dimensional nanostructures with precisely controlled size, shape and spatial functionalization. These nanostructures have been precisely patterned with molecules, proteins and gold nanoparticles for the observation of chemical reactions at the single molecule level, activation of enzymatic cascade and novel modality of photonic detection, respectively. Recently, they have also been engineered to encapsulate and release bioactive agents in a stimulus-responsive manner for therapeutic applications. The future of nucleic acid-based nanoengineering is bright and exciting. In this review, we will discuss the strategies to control the assembly of nucleic acids and highlight the recent efforts to build functional nucleic acid nanodevices for nanomedicine.
Synthesis of Hydroxylated Sterols in Transgenic Arabidopsis Plants Alters Growth and Steroid Metabolism
Authors: Beste Lisa , Nahar Nurun , Dalman Kerstin , Fujioka Shozo , Jonsson Lisbeth , Dutta Paresh C. , Sitbon Folke
Published: July 2011

To explore mechanisms in plant sterol homeostasis, we have here increased the turnover of sterols in Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum) plants by overexpressing four mouse cDNA encoding cholesterol hydroxylases (CHs), hydroxylating cholesterol at the C-7, C-24, C-25, or C-27 positions. Compared to the wild type, the four types of Arabidopsis transformant showed varying degrees of phenotypic alteration, the strongest one being in CH25 lines, which were dark-green dwarfs resembling brassinosteroid-related mutants. Gas chromatography-mass spectrometry analysis of extracts from wild-type Arabidopsis plants revealed trace levels of α and β forms of 7-hydroxycholesterol, 7-hydroxycampesterol, and 7-hydroxysitosterol. The expected hydroxycholesterol metabolites in CH7-, CH24-, and CH25 transformants were identified and quantified using gas chromatography-mass spectrometry. Additional hydroxysterol forms were also observed, particularly in CH25 plants. In CH24 and CH25 lines, but not in CH7 ones, the presence of hydroxysterols was correlated with a considerable alteration of the sterol profile and an increased sterol methyltransferase activity in microsomes. Moreover, CH25 lines contained clearly reduced levels of brassinosteroids, and displayed an enhanced drought tolerance. Equivalent transformations of potato plants with the CH25 construct increased hydroxysterol levels, but without the concomitant alteration of growth and sterol profiles observed in Arabidopsis. The results suggest that an increased hydroxylation of cholesterol and/or other sterols in Arabidopsis triggers compensatory processes, acting to maintain sterols at adequate levels.
Perturbation of Polyamine Catabolism Can Strongly Affect Root Development and Xylem Differentiation
Authors: Tisi Alessandra , Federico Rodolfo , Moreno Sandra , Lucretti Sergio , Moschou Panagiotis N. , Roubelakis-Angelakis Kalliopi A. , Angelini Riccardo , Cona Alessandra
Published: July 2011

Spermidine (Spd) treatment inhibited root cell elongation, promoted deposition of phenolics in cell walls of rhizodermis, xylem elements, and vascular parenchyma, and resulted in a higher number of cells resting in G1 and G2 phases in the maize (Zea mays) primary root apex. Furthermore, Spd treatment induced nuclear condensation and DNA fragmentation as well as precocious differentiation and cell death in both early metaxylem and late metaxylem precursors. Treatment with either N-prenylagmatine, a selective inhibitor of polyamine oxidase (PAO) enzyme activity, or N,N  1-dimethylthiourea, a hydrogen peroxide (H2O2) scavenger, reverted Spd-induced autofluorescence intensification, DNA fragmentation, inhibition of root cell elongation, as well as reduction of percentage of nuclei in S phase. Transmission electron microscopy showed that N-prenylagmatine inhibited the differentiation of the secondary wall of early and late metaxylem elements, and xylem parenchymal cells. Moreover, although root growth and xylem differentiation in antisense PAO tobacco (Nicotiana tabacum) plants were unaltered, overexpression of maize PAO (S-ZmPAO) as well as down-regulation of the gene encoding S-adenosyl-l-methionine decarboxylase via RNAi in tobacco plants promoted vascular cell differentiation and induced programmed cell death in root cap cells. Furthermore, following Spd treatment in maize and ZmPAO overexpression in tobacco, the in vivo H2O2 production was enhanced in xylem tissues. Overall, our results suggest that, after Spd supply or PAO overexpression, H2O2 derived from polyamine catabolism behaves as a signal for secondary wall deposition and for induction of developmental programmed cell death.
The increasing mortality burden of liver disease among opioid‐dependent people: cohort study
Authors: Gibson Amy , Randall Deborah , Degenhardt Louisa
Published: July 2011

Aims  Hepatitis C (HCV) infection is highly prevalent among injection drug users (IDUs) and likely to cause significant mortality over time, but little research attention has focused upon the magnitude of this risk, particularly among ageing users. This study examined trends over time in mortality attributed to liver disease, and in particular contrasting this with other more commonly studied causes of death [acquired immune deficiency syndrome (AIDS), suicide and overdose] among an ageing cohort of heroin‐dependent people in Australia.

Design  Data linkage study of methadone treatment entrants with the National Deaths Index.

Setting  A cohort entering methadone treatment for heroin dependence in New South Wales, Australia, 1980–85.

Participants  A total of 2489 people entering methadone treatment for heroin dependence and 54 847 person‐years (PY) of follow‐up.

Measurements  Linkage of data on all methadone entrants between 1980 and 1985 with data from the Australian National Deaths Index, linked using probabilistic record linkage software.

Findings  There were 8.2 deaths per 1000 PY [95% confidence interval (CI) 7.5–9.0], with standardized mortality ratios (SMRs) of 4.6 (95% CI 4.2–5.0). Almost one in five (17%) of deaths were from underlying liver‐related causes, most commonly viral hepatitis. The overall mortality rate for any liver cause was 1.4 deaths per 1000 PY (95% CI 1.1–1.7), 17 times higher than to the general population (95% CI 13.4–21.3), with relative elevations more marked for females (SMR 27.9; 95% CI 17.7–41.9) than males (SMR 14.5; 95% CI 10.8–19.0). Liver mortality increased over time, becoming the most common cause of death by the end of follow‐up.

Conclusions  Liver disease has become the most common cause of mortality among ageing opioid‐dependent people in an ageing Australian cohort. There is an imperative to reduce the long‐term risks of HCV and other risks to the liver, including alcohol consumption, which are typically not the major clinical focus for this group.
Family life cycle transitions and the onset of eating disorders: a retrospective grounded theory approach
Authors: Berge Jerica M , Loth Katie , Hanson Carrie , Croll‐Lampert Jillian , Neumark‐Sztainer Dianne
Published: July 2011

Aims and objective.  The aim of this retrospective qualitative study is to understand how transitions in the family life cycle and responses to these events may relate to the onset of eating disorders in an attempt to generate new theoretical insights and inform future research in the area of eating disorder prevention.

Background.  Little is known about the contextual factors that occur throughout the family life cycle that may be risk factors for the development of eating disorders.

Design and methods.  Semi‐structured interviews were conducted with 27 individuals of varied ages (age range = 17–64; median = 27; SD 13·7) currently receiving treatment for eating disorders in an outpatient clinic specialising in eating disorder treatment. Data were analysed using grounded theory methods.

Results.  Six themes were identified as family life cycle transitional events that preceded the onset of participants’ eating disorders: (1) school transitions, (2) death of a family member, (3) relationship changes, (4) home and job transitions (5) illness/hospitalisation and (6) abuse, sexual assault, or incest.

Conclusions.  Results indicated that transitional events in the family life cycle followed by a lack of needed support during these transitions may precipitate the onset of eating disorders. Thus, future research should use these findings to inform the creation of interventions that reduce the intensity of the stress brought about by these transitional periods and increase the adaptability and coping skills of individuals and family members to prevent eating disorders.

Relevance to clinical practice.  Nurses and other healthcare professionals should be aware of the importance of transitional events occurring in the family life cycle of adolescents and young adults. Helping parents to be aware and supportive of difficult transitional events may be more important than trying to solve or fix the problem.
Validation of the Brazilian version of the Nursing Work Index‐Revised (B‐NWI‐R)
Authors: Gasparino Renata C , de Brito Guirardello Edinêis , Aiken Linda H
Published: July 2011

Aims and objective.  The goal of this paper was to evaluate the reliability and validity of the Nursing Work Index‐Revised – Brazilian version (B‐NWI‐R).

Background.  Some instruments evaluate the presence of certain characteristics in the professional practice environment of nurses. Among them, the B‐NWI‐R, often cited in the literature and which is examined in the present study. This instrument is composed of 57 items and four subscales: autonomy, control over the work environment, nurse–physician relationships and organisational support.

Design.  A cross‐sectional research design was carried out in three public university hospitals in the State of São Paulo, Brazil.

Methods.  The sample was composed of 278 nurses. The reliability of the instrument was evaluated through its homogeneity, using the Cronbach’s alpha coefficient. The validity of the subscales of the B‐NWI‐R was evaluated through divergent construct validity and criterion‐related validity. For the divergent construct validity, the Brazilian version of the Maslach Burnout Inventory (MBI) was employed, while for the criterion‐related validity, variables such as ‘satisfaction at work’, ‘perception of quality of care’ and ‘nurses’ intention to leave work in the following year’ were considered.

Results.  The results showed satisfactory consistency for the total of the items (α = 0·95) and for the subscales of the B‐NWI‐R: ‘control over practice settings’ (α = 0·75); ‘nurse–physician relationships’ (α = 0·75); ‘organisational support’ (α = 0·75) and ‘autonomy’ (α = 0·63). The divergent validity resulted in significant correlation between the adapted instrument subscales and those of the MBI. In addition, a significant correlation was obtained between the subscales of the B‐NWI‐R and the variables ‘perception of quality of care’, ‘satisfaction at work’ and ‘intention to leave work in the following year’.

Conclusion.  The reliability and validity of the B‐NWI‐R have been established.

Relevance to clinical practice.  The B‐NWI‐R subscales can be used to assess the nurses’ perceptions of the work environment.
AtHaspin phosphorylates histone H3 at threonine 3 during mitosis and contributes to embryonic patterning in Arabidopsis
Authors: Ashtiyani Raheleh Karimi , Moghaddam Ali Mohammad Banaei , Schubert Veit , Rutten Twan , Fuchs Jörg , Demidov Dmitri , Blattner Frank R. , Houben Andreas
Published: July 2011

Post‐translational histone modifications regulate many aspects of chromosome activity. Threonine 3 of histone H3 is highly conserved, but the significance of its phosphorylation is unclear, and the identity of the corresponding kinase in plants is unknown. Therefore, we characterized the candidate kinase in Arabidopsis thaliana, called AtHaspin. Recombinant AtHaspin in vitro phosphorylates histone H3 at threonine 3. Reduction of H3 threonine 3 phosphorylation level and reduced chromatin condensation in interphase nuclei by AtHaspin RNAi supports the proposition that this kinase is involved in histone H3 phosphorylation in vivo in mitotic cells. In addition, we provide a developmental function for a Haspin kinase. At the whole plant level, altered expression of the kinase induced pleiotropic phenotypes with defects in floral organs and vascular tissue. It reduced fertility and modified adventitious shoot apical meristems that then gave rise to plants with multi‐rosettes and multi‐shoots. Haspin mutant embryos frequently showed alteration in division plane orientation that could be traced back to the earliest divisions of embryo development, thus Haspin contributes to embryonic patterning.
Arabidopsis Lateral Root Development 3 is essential for early phloem development and function, and hence for normal root system development
Authors: Ingram Paul , Dettmer Jan , Helariutta Yrjo , Malamy Jocelyn E.
Published: July 2011

We have identified a gene, Lateral Root Development 3 (LRD3), that is important for maintaining a balance between primary and lateral root growth. The lrd3 mutant has decreased primary root growth and increased lateral root growth. We determined that the LRD3 gene encodes a LIM‐domain protein of unknown function. LRD3 is expressed only in the phloem companion cells, which suggested a role in phloem function. Indeed, while phloem loading and export from the shoot appear to be normal, delivery of phloem to the primary root tip is limited severely in young seedlings. Abnormalities in phloem morphology in these seedlings indicate that LRD3 is essential for correct early phloem development. There is a subsequent spontaneous recovery of normal phloem morphology, which is correlated tightly with increased phloem delivery and growth of the primary root. The LRD3 gene is one of very few genes described to affect phloem development, and the only one that is specific to early phloem development. Continuous growth on auxin also leads to recovery of phloem development and function in lrd3, which demonstrates that auxin plays a key role in early phloem development. The root system architecture and the pattern of phloem allocation in the lrd3 root system suggested that there may be regulated mechanisms for selectively supporting certain lateral roots when the primary root is compromised. Therefore, this study provides new insights into phloem‐mediated resource allocation and its effects on plant root system architecture.
Matrix solubilization and cell wall weakening by β‐expansin (group‐1 allergen) from maize pollen
Authors: Tabuchi Akira , Li Lian‐Chao , Cosgrove Daniel J.
Published: July 2011

Beta‐expansins accumulate to high levels in grass pollen, a feature apparently unique to grasses. These proteins, which are major human allergens, facilitate pollen tube penetration of the maize stigma and style (the silk). Here we report that treatment of maize silk cell walls with purified β‐expansin from maize pollen led to solubilization of wall matrix polysaccharides, dominated by feruloyated highly substituted glucuronoarabinoxylan (60%) and homogalacturonan (35%). Such action was selective for cell walls of grasses, and indicated a target preferentially found in grass cell walls, probably the highly substituted glucuronoarabinoxylan. Several tests for lytic activities by β‐expansin were negative and polysaccharide solubilization had weak temperature dependence, which indicated a non‐enzymatic process. Concomitant with matrix solubilization, β‐expansin treatment induced creep, reduced the breaking force and increased the plastic compliance of wall specimens. From comparisons of the pH dependencies of these processes, we conclude that matrix solubilization was linked closely to changes in wall plasticity and breaking force, but not so closely coupled to cell wall creep. Because matrix solubilization and increased wall plasticity have not been found with other expansins, we infer that these novel activities are linked to the specialized role of grass pollen β‐expansins in promotion of penetration of the pollen tube through the stigma and style, most likely by weakening the middle lamella.
Late onset of hepatitis B virus reactivation following hematopoietic stem cell transplantation: successful treatment with combined entecavir plus tenofovir therapy
Authors: Milazzo L. , Corbellino M. , Foschi A. , Micheli V. , Dodero A. , Mazzocchi A. , Montefusco V. , Zehender G. , Antinori S.
Published: July 2011

L. Milazzo, M. Corbellino, A. Foschi, V. Micheli, A. Dodero, A. Mazzocchi, V. Montefusco, G. Zehender, S. Antinori. Late onset of hepatitis B virus reactivation following hematopoietic stem cell transplantation: successful treatment with combined entecavir plus tenofovir therapy. Transpl Infect Dis 2011. All rights reserved

Abstract: Prophylaxis with lamivudine (LAM) is recommended for hepatitis B core antibody‐positive allogenic hematopoietic stem cell transplant (HSCT) recipients, but the optimal timing for the institution and duration of the prophylaxis is still unknown. Furthermore, considering the high rate of mortality associated with hepatitis B virus reactivation (HBV‐R), the most potent and long‐term effective antiviral regimen should be considered. We report here a case of late onset of HBV‐R after a long‐term prophylaxis with LAM in a patient who underwent HSCT for non‐Hodgkin lymphoma and who was successfully treated with a combination antiviral regimen including entecavir and tenofovir disoproxil fumarate.
Changing the way we diagnose tuberculids with interferon gamma release assays
Authors: Koh Hong Yi , Tay Liang Kiat , Pang Shiu Ming , Ong Beng Hock
Published: July 2011

Diagnosing tuberculids traditionally requires clinicopathological correlation together with positive tuberculin skin tests (TST) or demonstration of Mycobacterium tuberculosis (MTB) DNA by polymerase chain reaction (PCR). Interferon gamma release assays (IGRA) are new laboratory tests approved for the diagnosis of MTB infection. We describe three patients with tuberculids who had no other clinical feature of tuberculosis (TB) infection and negative PCR of skin biopsies. Their diagnoses were aided by positive IGRA.
Concurrent spinal nerve root schwannoma and meningioma mimicking single‐component schwannoma
Authors: Nakamizo Akira , Suzuki Satoshi O. , Shimogawa Takafumi , Amano Toshiyuki , Mizoguchi Masahiro , Yoshimoto Koji , Sasaki Tomio
Published: July 2011

We present a first case of concurrent tumors consisting of schwannoma and meningioma arising at the same spinal level in a patient without neurofibromatosis. A 49‐year‐old man without clinical evidence of neurofibromatosis presented with a 5‐month history of right neck pain. MRI demonstrated an extradural tumor involving the right‐sided C2 nerve root with a small intradural component. T1‐ and T2‐weighted and contrast‐enhanced MRI could not differentiate the intradural tumor as different from the extradural tumor. Total removal of the tumors was performed. No contiguity of the extradural tumor with the intradural tumor was seen. The intradural tumor attached strongly to the dura mater around the C2 nerve root exits. Intraoperative pathological diagnosis confirmed the extradural tumor as schwannoma and the intradural tumor as meningioma. We therefore thoroughly coagulated the dura mater adjacent to the intradural tumor and resected the dura mater around the nerve root exits together with the tumor. Pathological examination revealed that the resection edge of the extradural component consisted of a spinal nerve with thickened epineurium and was free of neoplastic cells. No schwannoma component was evident in the intradural tumor. No obvious transition thus existed between the extra‐ and intradural tumors. Distinguishing these tumors prior to surgery is critical for determining an optimal surgical plan, as schwannoma and meningioma require different surgical procedures. We therefore recommend a careful review of preoperative imaging with the possibility of concurrent tumors in mind.
Brain vascular changes in Cockayne syndrome
Authors: Hayashi Masaharu , Miwa‐Saito Naho , Tanuma Naoyuki , Kubota Masaya
Published: July 2011

Cockayne syndrome (CS) and xeroderma pigmentosum (XP) are caused by deficient nucleotide excision repair. CS is characterized by cachectic dwarfism, mental disability, microcephaly and progeria features. Neuropathological examination of CS patients reveals dysmyelination and basal ganglia calcification. In addition, arteriosclerosis in the brain and subdural hemorrhage have been reported in a few CS cases. Herein, we performed elastica van Gieson (EVG) staining and immunohistochemistry for collagen type IV, CD34 and aquaporin 4 to evaluate the brain vessels in autopsy cases of CS, XP group A (XP‐A) and controls. Small arteries without arteriosclerosis in the subarachnoid space had increased in CS cases but not in either XP‐A cases or controls. In addition, string vessels (twisted capillaries) in the cerebral white matter and increased density of CD34‐immunoreactive vessels were observed in CS cases. Immunohistochemistry findings for aquaporin 4 indicated no pathological changes in either CS or XP‐A cases. Hence, the increased subarachnoid artery space may have caused subdural hemorrhage. Since such vascular changes were not observed in XP‐A cases, the increased density of vessels in CS cases was not caused by brain atrophy. Hence, brain vascular changes may be involved in neurological disturbances in CS.
Non‐invasive detection of spatio‐temporal activation of SBE and NFAT5 promoters in transgenic reporter mice following stroke
Authors: Shaterian Ashkaun , Borboa Alexandra , Coimbra Raul , Baird Andrew , Eliceiri Brian P.
Published: July 2011

The characterization of molecular responses following cerebral ischemia‐induced changes in animal models capable of undergoing real‐time analysis is an important goal for stroke research. In this study, we use transgenic mice to examine the activation of two different promoters in a firefly luciferase reporter mouse analyzable through a non‐invasive bioluminescent imaging system. In the first model, we examine the middle cerebral artery occlusion (MCAO)‐induced activation of Smad‐binding elements (SBE), a downstream target of Smad 1/2/3 transcription factors, in which SBEs regulate the expression of the fluc reporter. We observed that MCAO induces a bilateral activation (i.e., both ipsilateral and contralateral brain hemispheres) of the SBE‐luc reporter with a peak at 24 h. In the second model, we examined MCAO‐induced activation of the osmolarity‐sensitive promoter nuclear factor of activated T‐cell 5 (NFAT5) and identified a peak reporter expression 72 h post‐MCAO in the ipsilateral but not contralateral hemisphere. In each of these models, the assessment of post‐MCAO fluc‐expression provided both a quantitative measure (i.e., radiance in photons/sec/cm2/steradian) as well as qualitative localization of the molecular response following focal ischemic injury.
Fatigue resistance potential for hot mix asphalt using viscoelastic continuum damage analysis
Authors: MUN S. , LEE S.
Published: July 2011

This paper describes testing and evaluation of the fatigue resistance potential of hot‐mix asphalt mixtures using viscoelastic continuum damage analysis, which is based on dynamic modulus determination, a state‐variable approach and damage calculation. The dynamic modulus test for stiffness characterization and the direct tension test for fatigue resistance characterization were used in the testing procedure. The state‐variable approach can be used for numerical computation of a viscoelastic convolution integral. A Nelder–Mead simplex search was used in this study to determine the damage parameter of a stiffness reduction function. The fatigue resistance was evaluated as a function of loading rate, asphalt binder content, modifier (e.g. usage of hydrated lime), and temperature, and was found experimentally to have a strong dependence on these factors.
Role of P2X4 receptors in synaptic strengthening in mouse CA1 hippocampal neurons
Authors: Baxter Andrew W. , Choi Se Joon , Sim Joan A. , North R. Alan
Published: July 2011

P2X4 receptors are calcium‐permeable cation channels gated by extracellular ATP. They are found close to subsynaptic sites on hippocampal CA1 neurons. We compared features of synaptic strengthening between wild‐type and P2X4 knockout mice (21–26 days old). Potentiation evoked by a tetanic presynaptic stimulus (100 Hz, 1 s) paired with postsynaptic depolarization was less in P2X4−/− mice than in wild‐type mice (230 vs. 50% potentiation). Paired‐pulse ratios and the amplitude and frequency of spontaneous excitatory postsynaptic currents (EPSCs) were not different between wild‐type and knockout mice. Prior hyperpolarization (ten 3 s pulses to −120 mV at 0.17 Hz) potentiated the amplitude of spontaneous EPSCs in wild‐type mice, but not in P2X4−/− mice; this potentiation was not affected by nifedipine, but was abolished by 10 mm 1,2‐bis(o‐aminophenoxy)ethane‐N,N,N′,N′‐tetra‐acetic acid (BAPTA) in the recording pipette. The amplitude of N‐methyl‐d‐aspartate EPSCs (in 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione, 10 or 30 μm, at −100 mV) facilitated during 20 min recording in magnesium‐free solution. In wild‐type mice, this facilitation of the N‐methyl‐d‐aspartate EPSC was reduced by about 50% by intracellular BAPTA (10 mm), ifenprodil (3 μm) or 4‐(4‐fluorophenyl)‐2‐(4‐methylsulphinylphenyl)‐5‐(4‐pyridyl)1H‐imidazole (5 μm). In P2X4−/− mice, the facilitation was much less, and was unaffected by intracellular BAPTA, ifenprodil (3 μm) or mitogen‐activated protein (MAP) kinase inhibitor 4‐(4‐fluorophenyl)‐2‐(4‐methylsulphinylphenyl)‐5‐(4‐pyridyl)1H‐imidazole (5 μm). This suggests that the absence of P2X4 receptors limits the incorporation of NR2B subunits into synaptic N‐methyl‐d‐aspartate receptors.
Cocaine withdrawal reduces group I mGluR‐mediated long‐term potentiation via decreased GABAergic transmission in the amygdala
Authors: Schmidt Kady , Krishnan Balaji , Xia Yan , Sun Anyang , Orozco‐Cabal Luis , Pollandt Sebastian , Centeno Marjorie , Genzer Kathy , Gallagher Joel P. , Shinnick‐Gallagher Patricia , Liu Jie
Published: July 2011

Cocaine relapse can occur when cocaine‐associated environmental cues induce craving. Conditioned place preference (CPP) is a behavioral paradigm modeling the association between cocaine exposure and environmental cues. The amygdala is involved in cocaine cue associations with the basolateral amygdala (BLA) and central amygdala (CeA) acting differentially in cue‐induced relapse. Activation of metabotropic glutamate receptors induces synaptic plasticity, the mechanism of which is thought to underlie learning, memory and drug–cue associations. The goal of this study was to examine the neural alterations in responses to group I metabotropic glutamate receptor (mGluR) agonists in the BLA to lateral capsula of CeA (BLA–CeLc) pathway in slices from rats exposed to cocaine‐CPP conditioning and withdrawn for 14 days. mGluR1, but not mGluR5, agonist‐induced long‐term potentiation (mGluR1‐LTP) in the BLA–CeLc pathway was reduced in rats withdrawal from cocaine for 2 and 14 days, and exhibited an altered concentration response to picrotoxin. Cocaine withdrawal also reduced γ‐aminobutyric acid (GABA)ergic synaptic inhibition in CeLc neurons. Blocking cannabinoid receptor 1 (CB1) reduced mGluR1‐LTP in the saline‐treated but not cocaine‐withdrawn group. Response to CB1 but not CB2 agonist was altered after cocaine. Additionally, increasing endocannabinoid (eCB) levels abolished mGluR1‐LTP in the saline but not cocaine‐withdrawn group. However, CB1 and CB2 protein levels were increased in the amygdala of cocaine‐withdrawn rats while mGluR1 and mGluR5 remained unchanged. These data suggested that the mechanisms underlying the diminished mGluR1‐LTP in cocaine‐withdrawn rats involve an altered GABAergic synaptic inhibition mediated by modulation of downstream eCB signaling. These changes may ultimately result in potentiated responses to environmental cues that would bias behavior toward drug‐seeking.
Evolutionary trade‐offs among decomposers determine responses to nitrogen enrichment
Authors: Treseder Kathleen K. , Kivlin Stephanie N. , Hawkes Christine V.
Published: July 2011

Ecology Letters (2011) 14: 933–938

Evolutionary trade‐offs among ecological traits are one mechanism that could determine the responses of functional groups of decomposers to global changes such as nitrogen (N) enrichment. We hypothesised that bacteria targeting recalcitrant carbon compounds require relatively high levels of N availability to support the construction costs of requisite extracellular and transport enzymes. Indeed, we found that taxa that used more recalcitrant (i.e. larger and cyclic) carbon compounds were more prevalent in ocean waters with higher nitrate concentrations. Compared to recalcitrant carbon users, labile carbon users targeted more organic N compounds, were found in relatively nitrate‐poor waters, and were more common in higher latitude soils, which is consistent with the paradigm that N‐limitation is stronger at higher latitudes. Altogether, evolutionary trade‐offs may limit recalcitrant carbon users to habitats with higher N availability.
Effects of vitamin E and beta‐carotene on sperm competitiveness
Authors: Almbro Maria , Dowling Damian K. , Simmons Leigh W.
Published: July 2011

Ecology letters (2011) 14: 891–895

Sperm are particularly prone to oxidative damage because they generate reactive oxygen species (ROS), have a high polyunsaturated fat content and a reduced capacity to repair DNA damage. The dietary compounds vitamin E and beta‐carotene are argued to have antioxidant properties that help to counter the damaging effects of excess ROS. Here in, we tested the post‐copulatory consequences for male crickets (Teleogryllus oceanicus) of dietary intake of these two candidate antioxidants. During competitive fertilisation trials, vitamin E, but not beta‐carotene, singularly enhanced sperm competitiveness. However, the diet combining a high vitamin E dose and beta‐carotene produced males with the most competitive ejaculates, possibly due to the known ability of beta‐carotene to recycle vitamin E. Our results provide support for the idea that these two common dietary compounds have interactive antioxidant properties in vivo, by affecting the outcomes of male reproductive success under competitive conditions.
Field estimates of reproductive success in a model insect: behavioural surrogates are poor predictors of fitness
Authors: Thompson David J. , Hassall Christopher , Lowe Chris D. , Watts Phillip C.
Published: July 2011

Ecology Letters (2011) 14: 905–913

Understanding, and therefore measuring, factors that determine fitness is a central problem in evolutionary biology. We studied a natural population of Coenagrion puella (Odonata: Zygoptera) over two entire breeding seasons, with over a thousand individuals uniquely marked and genotyped, and all mating events at the rendezvous site recorded. Using a parentage analysis, fitness of individuals in the first generation was quantified as the numbers of offspring that survived to maturity. Although mating behaviour can be predicted by environmental and demographical variables, the numbers of mature offspring produced (fitness) cannot, and crucially, are poorly correlated with behavioural observations of mating. While fitness of both sexes was positively related to mating behaviour and to female’s ectoparasite burden, these behavioural observations explained little more variance in offspring production than environmental and demographical variables. Thus, we demonstrate that behavioural measures of reproductive success are not necessarily reliable estimates of fitness in natural populations.
Smoking is a major risk factor for anastomotic leak in patients undergoing low anterior resection
Authors: Richards C. H. , Campbell V. , Ho C. , Hayes J. , Elliott T. , Thompson‐Fawcett M.
Published: July 2011

Aim  To examine modifiable risk factors for anastomotic leak in patients undergoing low anterior resection.

Method  In total 233 patients undergoing low anterior resection for benign and malignant disease over a 10‐year period at a single surgical unit were identified from a prospective database. The relationships between anastomotic leak and 17 variables were examined, including patient demographics, operative technique, tumour pathology, preoperative physiological function and smoking status.

Results  The majority (91%) of operations were carried out for rectal cancers, and 24 procedures (10%) were performed with laparoscopic assistance. The overall anastomotic leak rate was 14% (33/233). Patients with anastomotic leak had higher 30‐day mortality (6%vs 1%, P < 0.05) and stayed significantly longer in hospital (median 23 vs 10 days, P < 0.001). On multivariate analysis, current smokers (OR 3.68, 95% CI 1.38–9.82, P = 0.009) and patients with evidence of metastatic malignant disease (OR 3.43, 95% CI 1.29–9.13, P =0.013) were at increased risk of anastomotic leak.

Conclusion  Smoking and the presence of metastatic disease are major risk factors for the development of anastomotic leak following low anterior resection.
Ultrastructure features of camel cornea – collagen fibril and proteoglycans
Authors: Almubrad Turki , Akhtar Saeed
Published: July 2011

Introduction  The uniform distribution of collagen fibrils and proteoglycans maintain the transparency of normal cornea. We describe the ultrastructural features of camel cornea including collagen fibrils and proteoglycans (PGs).

Methods  Camel corneas (of 6‐, 8‐, and 10‐month‐old animals) were fixed in 2.5% glutaraldehyde containing cuprolinic blue in sodium acetate buffer and processed for electron microscopy. The ‘AnalySIS LS Professional’ program was used to analyze the collagen fibril diameter.

Results  The camel cornea consists of four layers: the epithelium (227 μm), stroma (388 μm), Descemet’s membrane (DM), and endothelium. The epithelium constituted 36% of the camel cornea, whereas corneal stroma constituted 62% of the corneal thickness (629 μm). The PGs in the posterior stroma were significantly larger in number and size compared with the anterior and middle stroma. The collagen fibril diameter was 25 nm and interfibrillar spacing 40 nm. Fibrillar structures are present throughout the DM.

Conclusion  The structure of the camel cornea is very different from human and other animals. The unique structure of the cornea might be an adaptation to help the camel to survive in a hot and dry climate. The camel cornea may also be a good model to study the effect of hot and dry climates on the cornea.
Scleral and suprachoroidal foreign body in a dog – a case report
Authors: Welihozkiy Anja , Pirie Christopher G. , Pizzirani Stefano
Published: July 2011

A 2‐year‐old male castrated Springer Spaniel with a 3‐week history of waxing and waning right sided exophthalmos, periorbital swelling, chemosis, and fundic changes was examined. Ophthalmic examination of the right eye revealed slight chemosis and nictitating membrane protrusion. Indirect ophthalmoscopy showed an approximately 8 mm peripapillary hyporeflective tapetal lesion with subretinal edema consistent with a bulbar/retrobulbar disease process. Inflammatory or neoplastic diseases were the main differential diagnoses. Ancillary diagnostics (ocular ultrasound and computed tomography) showed a focal, poorly defined dense tissue involving the caudomedial aspect of the right globe, adjacent to the optic nerve head without apparent orbital involvement. Considering the duration, location, and severity of the clinical findings, enucleation of the right globe was performed. Histopathology revealed focal thickening of the posterior wall with severe pyogranulomatous inflammation, surrounding a foreign body most consistent with plant material embedded between the sclera and the choroid (suprachoroidal). This report describes a rare case of a scleral/suprachoroidal foreign body (plant material), and outlines the difficulty of establishing an etiological diagnosis using standard ocular imaging.
Adipose tissue dysfunction and hypertriglyceridemia: mechanisms and management
Authors: van de Woestijne A. P. , Monajemi H. , Kalkhoven E. , Visseren F. L. J.
Published: July 2011

Elevated plasma triglyceride levels, as often seen in obese subjects, are independently associated with an increased risk of cardiovascular diseases. By secreting adipokines (such as adiponectin and leptin) and other proteins (such as lipoprotein lipase and cholesteryl ester transferase protein), adipose tissue affects triglyceride metabolism. In obesity, adipocyte hypertrophy leads to many changes in adipocyte function and production of anti‐ and pro‐inflammatory cytokines. Furthermore, free fatty acids are released into the circulation contributing to insulin resistance. Adipose tissue dysfunction will eventually lead to abnormalities in lipid metabolism, such as hypertriglyceridemia (due to increased hepatic very‐low‐density lipoprotein production and decreased triglyceride hydrolysis), small dense low‐density lipoprotein particles, remnant lipoproteins and low high‐density lipoprotein cholesterol levels, all associated with a higher risk for the development of cardiovascular diseases. The clinical implications of elevated plasma triglycerides are still a matter of debate. Understanding the pathophysiology of adipose tissue dysfunction in obesity, which is becoming a pandemic condition, is essential for designing appropriate therapeutic interventions. Lifestyle changes are important to improve adipose tissue function in obese patients. Pharmacological interventions to improve adipose tissue function need further evaluation. Although statins are not very potent in reducing plasma triglycerides, they remain the mainstay of therapy for cardiovascular risk reduction in high‐risk patients.
Target‐mask shape congruence impacts the type of metacontrast masking
Authors: MAKSIMOV MARGUS , MURD CAROLINA , BACHMANN TALIS
Published: July 2011

Maksimov, M., Murd, C. & Bachmann, T. (2011). Target‐mask shape congruence impacts the type of metacontrast masking. Scandinavian Journal of Psychology 52, 524–529.

Visual metacontrast masking may depend on the time intervals between target and mask in two qualitatively different ways: in type‐A masking the smaller the mask delay from target the stronger the masking while in type‐B masking maximal masking effect is obtained with a larger temporal delay of the mask. Variability in the qualitative apperance of masking functions has been explained by variability in stimuli parameters and tasks. Recent research on metacontrast masking has surprisingly shown that both of these types of functions can be found with an identical range of stimulation parameters depending on individual differences between observers. Here we show that obtaining clear‐cut type‐A masking depends on whether target and mask shapes are congruent or incongruent and whether observers use the cues available due to the congruence factor. Conspicuously expressed type‐A masking is selectively associated with incongruent target‐mask pairings. In the latter conditions target identification level significantly drops with the shortest target‐to‐mask delays.
The Relations between Infant Negative Reactivity, Non‐maternal Childcare, and Children's Interactions with Familiar and Unfamiliar Peers
Authors: Almas Alisa N. , Degnan Kathryn Amey , Fox Nathan A. , Phillips Deborah A. , Henderson Heather A. , Moas Olga L. , Hane Amie Ashley
Published: July 2011

The present study examined the influence of children's experiences during non‐maternal childcare on their behavior toward unfamiliar peers. Participants included children classified as negatively reactive at four months of age (N = 52) and children not negatively reactive (N = 61), who were further divided into those who experienced non‐maternal care and those who did not. Children were observed during childcare at 24 months of age and in the laboratory with an unfamiliar peer at 24 and 36 months of age, where their wariness, dysregulation, and social engagement were assessed. Within the negatively reactive childcare group, children's positive interactions with peers during childcare at 24 months predicted lower levels of wariness toward an unfamiliar peer at 36 months. This relation was not significant for children not classified as negatively reactive. The findings suggest that the influence of non‐maternal childcare is dependent on a child's temperament and on the nature of peer interactions during care.
Caregiver Emotional Expressiveness, Child Emotion Regulation, and Child Behavior Problems among Head Start Families
Authors: McCoy Dana Charles , Raver C. Cybele
Published: July 2011

The present study examined the relationships between caregivers' self‐reported positive and negative emotional expressiveness, observer assessments of children's emotion regulation, and teachers' reports of children's internalizing and externalizing behaviors in a sample of 97 primarily African American and Hispanic Head Start families. Results indicated that higher caregiver negativity and lower child emotion regulation independently predicted more internalizing behavior problems in children. Additionally, children's externalizing behavior problems were negatively predicted by caregivers' self‐reports of positive emotional expressiveness. Importantly, results also suggested that caregivers' emotional expressiveness and children's behavioral problems may be non‐linearly related, and that child gender may play an important moderating role. These results emphasize the importance of family emotional climate and child emotion regulation in the behavioral development of preschool‐age children, and highlight the need for improved theoretical and practical understanding of socioemotional development in diverse populations.
Longitudinal Pathways between Maternal Mental Health in Infancy and Offspring Romantic Relationships in Adulthood: A 30‐year Prospective Study
Authors: Slominski Lisa , Sameroff Arnold , Rosenblum Katherine , Kasser Tim
Published: July 2011

Longitudinal pathways between maternal mental health in infancy and offspring romantic relationship outcomes in adulthood were examined using a 30‐year prospective longitudinal study of 196 mothers and their children. Structural equation modeling revealed that maternal mental health at 30 months was related to offspring relationship status and relationship attachment insecurity at 30 years. The adolescent variables of offspring mental health and parental relationship status mediated the link between maternal mental health and offspring relationship status. In addition, adolescent mental health and family conflict mediated the pathway between maternal mental health and offspring attachment insecurity. These results highlight the importance of individual and parental mental health to romantic relationship outcomes, and emphasize the value of taking a developmental approach to the study of romantic relationships.
The Role of Respect in the Relation of Aggression to Popularity
Authors: Kuryluk Amanda , Cohen Robert , Audley‐Piotrowski Shannon
Published: July 2011

Can aggressive children be popular with peers? Generally, sociometric popularity (liking nominations) has been shown to be negatively associated with aggression, and perceived popularity (popularity nominations) has been shown to be positively associated with aggression. The thesis of the present research was that being respected by peers moderates the relation between aggression and popularity. For both third‐ through sixth‐grade boys (N = 107) and girls (N = 117), perceived popularity by peers was positively associated with nominations for aggression (both overt and relational) only for children high in respect. Aggression was negatively associated with sociometric popularity for girls who were low in respect; sociometric popularity for girls high in respect was not related to aggression nominations. In sum, aggressive children were considered to be popular only if they were respected; aggressive girls were not disliked if they were respected.