bluuebunny/crossref_metadata_2025 huggingface dataset:
Buckling, stiffening, and negative dissipation in the dynamics of a biopolymer in an active medium
Authors: Kikuchi Norio , Ehrlicher Allen , Koch Daniel , Käs Josef A. , Ramaswamy Sriram , Rao Madan
Published: November 2009

We present a generic theory for the dynamics of a stiff filament under tension, in an active medium with orientational correlations, such as a microtubule in contractile actin. In sharp contrast to the case of a passive medium, we find the filament can stiffen, and possibly oscillate or buckle, depending on both the contractile or tensile nature of the activity and the filament-medium anchoring interaction. We also demonstrate a strong violation of the fluctuation–dissipation (FD) relation in the effective dynamics of the filament, including a negative FD ratio. Our approach is also of relevance to the dynamics of axons, and our model equations bear a remarkable formal similarity to those in recent work [Martin P, Hudspeth AJ, Juelicher F (2001) Proc Natl Acad Sci USA 98:14380–14385] on auditory hair cells. Detailed tests of our predictions can be made by using a single filament in actomyosin extracts or bacterial suspensions.
RAGE-mediated signaling contributes to intraneuronal transport of amyloid-β and neuronal dysfunction
Authors: Takuma Kazuhiro , Fang Fang , Zhang Wensheng , Yan Shiqiang , Fukuzaki Emiko , Du Heng , Sosunov Alexander , McKhann Guy , Funatsu Yoko , Nakamichi Noritaka , Nagai Taku , Mizoguchi Hiroyuki , Ibi Daisuke , Hori Osamu , Ogawa Satoshi , Stern David M. , Yamada Kiyofumi , Yan Shirley ShiDu
Published: November 2009

Intracellular amyloid-β peptide (Aβ) has been implicated in neuronal death associated with Alzheimer's disease. Although Aβ is predominantly secreted into the extracellular space, mechanisms of Aβ transport at the level of the neuronal cell membrane remain to be fully elucidated. We demonstrate that receptor for advanced glycation end products (RAGE) contributes to transport of Aβ from the cell surface to the intracellular space. Mouse cortical neurons exposed to extracellular human Aβ subsequently showed detectable peptide intracellularly in the cytosol and mitochondria by confocal microscope and immunogold electron microscopy. Pretreatment of cultured neurons from wild-type mice with neutralizing antibody to RAGE, and neurons from RAGE knockout mice displayed decreased uptake of Aβ and protection from Aβ-mediated mitochondrial dysfunction. Aβ activated p38 MAPK, but not SAPK/JNK, and then stimulated intracellular uptake of Aβ-RAGE complex. Similar intraneuronal co-localization of Aβ and RAGE was observed in the hippocampus of transgenic mice overexpressing mutant amyloid precursor protein. These findings indicate that RAGE contributes to mechanisms involved in the translocation of Aβ from the extracellular to the intracellular space, thereby enhancing Aβ cytotoxicity.
Canonical Wnt signaling negatively regulates platelet function
Authors: Steele Brian M. , Harper Matthew T. , Macaulay Iain C. , Morrell Craig N. , Perez-Tamayo Alita , Foy Martina , Habas Raymond , Poole Alastair W. , Fitzgerald Desmond J. , Maguire Patricia B.
Published: November 2009

Wnts regulate important intracellular signaling events, and dysregulation of the Wnt pathway has been linked to human disease. Here, we uncover numerous Wnt canonical effectors in human platelets where Wnts, their receptors, and downstream signaling components have not been previously described. We demonstrate that the Wnt3a ligand inhibits platelet adhesion, activation, dense granule secretion, and aggregation. Wnt3a also altered platelet shape change and inhibited the activation of the small GTPase RhoA. In addition, we found the Wnt-β-catenin signaling pathway to be functional in platelets. Finally, disruption of the Wnt Frizzled 6 receptor in the mouse resulted in a hyperactivatory platelet phenotype and a reduced sensitivity to Wnt3a. Taken together our studies reveal a novel functional role for Wnt signaling in regulating anucleate platelet function and may provide a tractable target for future antiplatelet therapy.
The homeotic gene
long sterile lemma
(
G1
) specifies sterile lemma identity in the rice spikelet
Authors: Yoshida Akiko , Suzaki Takuya , Tanaka Wakana , Hirano Hiro-Yuki
Published: November 2009

The mechanism of floral organ specification is principally conserved in angiosperms, as demonstrated by the ABC model. By contrast, mechanisms that regulate the development of organs or structures specific to a group of species remain unclear. Grasses have unique inflorescence units, comprising spikelets and florets. In the genus
Oryza
(rice), the single spikelet consists of a fertile floret subtended by a lemma and a palea, two sterile lemmas, and rudimentary glumes. Each sterile lemma is a tiny glume-like organ with a smooth surface. Here, we have examined a
long sterile lemma1
(
g1
) mutant, in which the sterile lemma is enlarged like the lemma. Detailed phenotypic analysis reveals that the large sterile lemma in the
g1
mutant appears to be caused by homeotic transformation of the sterile lemma into a lemma, suggesting that
G1
is involved in the repression of lemma identity to specify the sterile lemma. Gene isolation reveals that
G1
is a member of a plant-specific gene family that encodes proteins with a previously uncharacterized domain, named here ALOG (
Arabidopsis LSH1
and
Oryza G1
).
G1
mRNA is expressed in sterile lemma primordia throughout their development, and G1 protein is localized in the nucleus. A trans-activation assay using the yeast GAL4 system suggests that G1 is involved in transcriptional regulation. Repression of lemma identity by
G1
is consistent with a hypothesis proposed to explain the morphological evolution of rice spikelets. We also show that a wild rice species,
Oryza grandiglumis
, that forms large sterile lemmas has serious mutations in the
G1
gene.
Rescue of radiation-induced cognitive impairment through cranial transplantation of human embryonic stem cells
Authors: Acharya Munjal M. , Christie Lori-Ann , Lan Mary L. , Donovan Peter J. , Cotman Carl W. , Fike John R. , Limoli Charles L.
Published: November 2009

Cranial irradiation remains a frontline treatment for the control of tumor growth, and individuals surviving such treatments often manifest various degrees of cognitive dysfunction. Radiation-induced depletion of stem/precursor cell pools in the brain, particularly those residing in the neurogenic region of the hippocampus, is believed, in part, to be responsible for these often-unavoidable cognitive deficits. To explore the possibility of ameliorating radiation-induced cognitive impairment, athymic nude rats subjected to head only irradiation (10 Gy) were transplanted 2 days afterward with human embryonic stem cells (hESC) into the hippocampal formation and analyzed for stem cell survival, differentiation, and cognitive function. Animals receiving hESC transplantation exhibited superior performance on a hippocampal-dependent cognitive task 4 months postirradiation, compared to their irradiated surgical counterparts that did not receive hESCs. Significant stem cell survival was found at 1 and 4 months postirradiation, and transplanted cells showed robust migration to the subgranular zone throughout the dentate gyrus, exhibiting signs of neuron morphology within this neurogenic niche. These results demonstrate the capability to ameliorate radiation-induced normal tissue injury using hESCs, and suggest that such strategies may provide useful interventions for reducing the adverse effects of irradiation on cognition.
Improved health and survival of FIV-infected cats is associated with the presence of autoantibodies to the primary receptor, CD134
Authors: Grant Chris K. , Fink Elizabeth A. , Sundstrom Magnus , Torbett Bruce E. , Elder John H.
Published: November 2009

We analyzed antibody responses in sera from feline immunodeficiency virus (FIV)-infected and uninfected cats. A strong antiviral response to the viral surface glycoprotein (SU) was noted in both natural and experimental infections. In addition, 143 of 226 FIV-infected animals (63%) also expressed antibodies to the primary binding receptor, CD134, whereas cats infected with other feline RNA viruses, including calicivirus, coronavirus, herpesvirus, and feline leukemia virus, did not. Both affinity-purified anti-CD134 and anti-SU antibodies blocked FIV infection
ex vivo
. FACS analyses revealed that the anti-CD134 antibodies bound to a cryptic epitope on the receptor that was only exposed when SU bound to CD134. Anti-CD134 binding caused displacement of SU from the surface of the cell and inhibition of infection. The presence of antibodies to CD134 correlated with lower virus loads and a better overall health status in FIV
+
cats, whereas anti-SU antibodies were present independent of health status. The findings are consistent with a role for antireceptor antibodies in protection from virus spread and disease progression.
Membrane expansion alleviates endoplasmic reticulum stress independently of the unfolded protein response
Authors: Schuck Sebastian , Prinz William A. , Thorn Kurt S. , Voss Christiane , Walter Peter
Published: November 2009

Cells constantly adjust the sizes and shapes of their organelles according to need. In this study, we examine endoplasmic reticulum (ER) membrane expansion during the unfolded protein response (UPR) in the yeast Saccharomyces cerevisiae. We find that membrane expansion occurs through the generation of ER sheets, requires UPR signaling, and is driven by lipid biosynthesis. Uncoupling ER size control and the UPR reveals that membrane expansion alleviates ER stress independently of an increase in ER chaperone levels. Converting the sheets of the expanded ER into tubules by reticulon overexpression does not affect the ability of cells to cope with ER stress, showing that ER size rather than shape is the key factor. Thus, increasing ER size through membrane synthesis is an integral yet distinct part of the cellular program to overcome ER stress.
Key role of T cell defects in age-related vulnerability to West Nile virus
Authors: Brien James D. , Uhrlaub Jennifer L. , Hirsch Alec , Wiley Clayton A. , Nikolich-Žugich Janko
Published: November 2009

West Nile virus (WNV) infection causes a life-threatening meningoencephalitis that becomes increasingly more prevalent over the age of 50 and is 40–50× more prevalent in people over the age of 70, compared with adults under the age of 40. In a mouse model of age-related vulnerability to WNV, we demonstrate that death correlates with increased viral titers in the brain and that this loss of virus control with age was the result of defects in the CD4 and CD8 T cell response against WNV. Specific age-related defects in T cell responses against dominant WNV epitopes were detected at the level of cytokine and lytic granule production, each of which are essential for resistance against WNV, and in the ability to generate multifunctional anti-WNV effector T cells, which are believed to be critical for robust antiviral immunity. In contrast, at the peak of the response, old and adult T cells exhibited superimposable peptide sensitivity. Most importantly, although the adult CD4 or CD8 T cells readily protected immunodeficient mice upon adoptive transfer, old T cells of either subset were unable to provide WNV-specific protection. Consistent with a profound qualitative and quantitative defect in T cell immunity, old brains contained at least 12× fewer total effector CD8 T cells compared with adult mice at the peak of brain infection. These findings identify potential targets for immunomodulation and treatment to combat lethal WNV infection in the elderly.
Two loci control tuberculin skin test reactivity in an area hyperendemic for tuberculosis
Authors: Cobat Aurelie , Gallant Caroline J. , Simkin Leah , Black Gillian F. , Stanley Kim , Hughes Jane , Doherty T. Mark , Hanekom Willem A. , Eley Brian , Jaïs Jean-Philippe , Boland-Auge Anne , van Helden Paul , Casanova Jean-Laurent , Abel Laurent , Hoal Eileen G. , Schurr Erwin , Alcaïs Alexandre
Published: November 2009

Approximately 20% of persons living in areas hyperendemic for tuberculosis (TB) display persistent lack of tuberculin skin test (TST) reactivity and appear to be naturally resistant to infection by Mycobacterium tuberculosis. Among those with a positive response, the intensity of TST reactivity varies greatly. The genetic basis of TST reactivity is not known. We report on a genome-wide linkage search for loci that have an impact on TST reactivity, which is defined either as zero versus nonzero (TST-BINa) or as extent of TST in millimeters (TST–quantitative trait locus [QTL]) in a panel of 128 families, including 350 siblings, from an area of South Africa hyperendemic for TB. We detected a major locus (TST1) on chromosomal region 11p14 (P = 1.4 × 10−5), which controls TST-BINa, with a lack of responsiveness indicating T cell–independent resistance to M. tuberculosis. We also detected a second major locus (TST2) on chromosomal region 5p15 (P < 10−5), which controls TST-QTL or the intensity of T cell–mediated delayed type hypersensitivity (DTH) to tuberculin. Fine mapping of this region identified SLC6A3, encoding the dopamine transporter DAT1, as a promising gene for further studies. Our results pave the way for the understanding of the molecular mechanisms involved in resistance to M. tuberculosis infection in endemic areas (TST1) and for the identification of critical regulators of T cell–dependent DTH to tuberculin (TST2).
A Parametric Study on the Immunomodulatory Effects of Electroacupuncture in DNP‐KLH Immunized Mice
Authors: Kim Sun Kwang , Lee Youngseop , Cho Hyunjoo , Koo Sungtae , Choi Sun Mi , Shin Min-Kyu , Hong Moo-Chang , Min Byung-Il , Bae Hyunsu
Published: November 2009

This study was conducted to compare the effects of low frequency electroacupuncture (EA) and high frequency EA at acupoint ST36 on the production of IgE and Th1/Th2 cytokines in BALB/c mice that had been immunized with 2,4‐dinitrophenylated keyhole limpet protein (DNP‐KLH), as well as to investigate the difference in the immunomodulatory effects exerted by EA stimulations at acupoint ST36 and at a non‐acupoint (tail). Female BALB/c mice were divided into seven groups: normal (no treatments), IM (immunization only), ST36‐PA (IM + plain acupuncture at ST36), ST36‐LEA (IM + low frequency (1 Hz) EA at ST36), ST36‐HEA (IM + high frequency (120 Hz) EA at ST36), NA‐LEA (IM + low frequency (1 Hz) EA at non‐acupoint) and NA‐HEA (IM + high frequency (120 Hz) EA at non‐acupoint). EA stimulation was performed daily for two weeks, and total IgE, DNP‐KLH specific IgE, IL‐4 and IFN‐γ levels were measured at the end of the experiment. The results of this study showed that the IgE and IL‐4 levels were significantly suppressed in the ST36‐LEA and ST36‐HEA groups, but not in the NA‐LEA and NA‐HEA groups. However, there was little difference in the immunomodulatory effects observed in the ST36‐LEA and ST36‐HEA groups. Taken together, these results suggest that EA stimulation‐induced immunomodulation is not frequency dependent, but that it is acupoint specific.
Total stock size and cannibalism regulate recruitment in cod (Gadus morhua) on the Faroe Plateau
Authors: Steingrund Petur , Mouritsen Rógvi , Reinert Jákup , Gaard Eilif , Hátún Hjálmar
Published: November 2009

Steingrund, P., Mouritsen, R., Reinert, J., Gaard, E., and Hátún, H. 2010. Total stock size and cannibalism regulate recruitment in cod (Gadus morhua) on the Faroe Plateau. – ICES Journal of Marine Science, 67: 111–124. Year-class strength of fish is often considered to be determined at the pelagic larval stage, but we show that year-class strength of cod on the Faroe Plateau seems to be determined later, at the 1- or 2-group stage. Adult cod (C), measured in terms of the catch per unit effort (cpue) of small longliners, move into nearshore nursery areas of juvenile cod when in poor condition and probably displace 1-year-old cod to deeper water, where they are cannibalized. In addition, the recruitment of 2-year-old cod, at least up to a certain level, is positively related to the total biomass (B) of older cod on the Faroe Plateau, which are present at about the same time as the recruitment event. This feature, which seems to be a new observation in terms of the recruitment dynamics of cod, is possibly related to enhanced foraging or a reduced predation risk. The recruitment of 2-year-old cod during the years 1984–2006 is described by aB/C + d (r2 = 0.87), where a and d are fitted constants. The implications for stock assessment and management are discussed.
Differences in Carbohydrate Composition and Digestion In Vitro of Selected Barley Cultivars as Influenced by Pearling and Cooking
Authors: Gray Danielle , Abdel‐Aal El‐Sayed M. , Seetharaman Koushik , Kakuda Yukio
Published: November 2009

Among common cereals, barley is a low glycemic index food. In an attempt to better understand this character, the nutritional properties of glycemic carbohydrates and dietary fiber concentrations of nine cultivars were evaluated. The cultivars were selected based on botanical variations and commercial value to investigate the impact of pearling and cooking on nutritional properties. Each cultivar was pearled into four fractions ranging from hull removal only to hull, bran, germ, and crease removal. The study showed that botanical class and degree of pearling significantly affect the carbohydrate composition and digestion indices of barley. Waxy starch cultivars had less total starch and more rapidly digestible starch (RDS), rapidly available glucose (RAG), and β‐glucan than the other nonwaxy cultivars. Regardless of the barley type, the less pearled kernels had significantly lower total starch and higher total low molecular weight sugars, insoluble, and total fiber. However, β‐glucan content was fairly comparable in the whole grain and pearled fractions. Cooking had a significant effect on nutritional properties of Celebrity and AC Klinck cultivars. The only consistent significant difference between raw and cooked barley was resistant starch (RS), which increased after cooking regardless of cultivar or fraction. The study showed that barley cultivar and carbohydrate composition significantly affected starch digestion with some cultivar fractions holding a promise for the development of low glycemic index foods.
Trend estimation in populations with imperfect detection
Authors: Kéry Marc , Dorazio Robert M. , Soldaat Leo , Van Strien Arco , Zuiderwijk Annie , Royle J. Andrew
Published: November 2009

1.Trends of animal populations are of great interest in ecology but cannot be directly observed owing to imperfect detection. Binomial mixture models use replicated counts to estimate abundance, corrected for detection, in demographically closed populations. Here, we extend these models to open populations and illustrate them using sand lizardLacerta agiliscounts from the national Dutch reptile monitoring scheme.

2.Our model requires replicated counts from multiple sites in each of several periods, within which population closure is assumed. Counts are described by a hierarchical generalized linear model, where the state model deals with spatio‐temporal patterns in true abundance and the observation model with imperfect counts, given that true state. We used WinBUGS to fit the model to lizard counts from 208 transects with 1–10 (mean 3) replicate surveys during each spring 1994–2005.

3.Our state model for abundance contained two independent log‐linear Poisson regressions on year for coastal and inland sites, and random site effects to account for unexplained heterogeneity. The observation model for detection of an individual lizard contained effects of region, survey date, temperature, observer experience and random survey effects.

4.Lizard populations increased in both regions but more steeply on the coast. Detectability increased over the first few years of the study, was greater on the coast and for the most experienced observers, and highest around 1 June. Interestingly, the population increase inland was not detectable when the observed counts were analysed without account of detectability. The proportional increase between 1994 and 2005 in total lizard abundance across all sites was estimated at 86% (95% CRI 35–151).

5.Synthesis and applications.Open‐population binomial mixture models are attractive for studying true population dynamics while explicitly accounting for the observation process, i.e. imperfect detection. We emphasize the important conceptual benefit provided by temporal replicate observations in terms of the interpretability of animal counts.
Reliability and validity in a nutshell
Authors: Bannigan Katrina , Watson Roger
Published: November 2009

Aims.  To explore and explain the different concepts of reliability and validity as they are related to measurement instruments in social science and health care.

Background.  There are different concepts contained in the terms reliability and validity and these are often explained poorly and there is often confusion between them.

Design.  To develop some clarity about reliability and validity a conceptual framework was built based on the existing literature.

Results.  The concepts of reliability, validity and utility are explored and explained.

Conclusions.  Reliability contains the concepts of internal consistency and stability and equivalence. Validity contains the concepts of content, face, criterion, concurrent, predictive, construct, convergent (and divergent), factorial and discriminant. In addition, for clinical practice and research, it is essential to establish the utility of a measurement instrument.

Relevance to clinical practice.  To use measurement instruments appropriately in clinical practice, the extent to which they are reliable, valid and usable must be established.
Job stress and intention to quit in newly‐graduated nurses during the first three months of work in Taiwan
Authors: Yeh Ming‐Chen , Yu Shu
Published: November 2009

Aims and objectives.  To identify job stress and intention to quit in newly‐graduated nurses during the first three months of their work at two different levels of hospitals and to understand factors that may influence their retention.

Background.  Given the current nursing shortage, retention of newly‐graduated nurses is crucial.

Design.  A cross‐sectional research design was adopted.

Methods.  Newly‐graduated nurses’ perceptions of job stress and intention to quit at different time periods during the first three months in addition to related factors were measured using structured questionnaires in two levels of hospitals in central Taiwan.

Results.  Subjects experienced somewhat stressful conditions (Mean = 2·89, SD 0·62) and 31·5% intended to quit. Job stress was the highest at 0–1 month and the intention to quit was highest at 1–2 months. The intention‐to‐quit group had significantly higher job stress with regard to roles/interpersonal relationships than the intention‐to‐stay group [t(144) = 2·65, p = 0·009]. Logistic regressions indicated that higher job stress (odds ratio = 2·26; 95% CI 1·14–4·51), working at a medical centre (odds ratio = 3·61; 95% CI 1·10–10·92) and not having had a clinical practicum in the working hospital (odds ratio = 2·41; 95% CI 1·01–5·77) were significant predictors associated with the intention to quit.

Conclusions.  Newly‐graduated nurses perceived moderate job stress which significantly influenced their intention to quit. Nursing administrators should assist newly‐graduated nurses in role adaptation and interpersonal relationships particularly to those who had previously worked only in medical centres and had never done a clinical practicum in the hospital.

Relevance to clinical practice.  Our findings provide concrete directions to nursing administrators in developing a stress‐alleviation programme to decrease newly‐graduate nurses’ job stress, to facilitate them successful entry into practice and to decrease their intention to quit.
The prevalence of pressure ulcers in four paediatric institutions
Authors: Schlüer Anna‐Barbara , Cignacco Eva , Müller Marianne , Halfens Ruud J
Published: November 2009

Aim and objective.  Pressure ulcers are a common nursing care issue in hospitals. They are associated with psychological and physical suffering, an increased morbidity and mortality rate and higher overall health care costs. The aim of the current study is to describe the frequency of pressure ulcers in a paediatric care setting and to identify the population at risk, as well as to assess the factors predisposing to the development of pressure ulcers.

Design.  A point prevalence study.

Methods.  The study was conducted in four paediatric hospitals in the German‐speaking part of Switzerland and included children from the age of 0–18 years. The method of data collection was a direct systematic inspection and assessment of the skin, taking into account the clinical condition of the patient for risk assessment. A valid risk assessment and data collection instrument was used and, each patient was assessed by a previously instructed rater pair.

Results.  Of all possible patients, 81% (n = 155) were included. An overall pressure ulcer prevalence of 27·7% (including grade 1) was registered. Thirty‐six patients (84%) had grade 1 ulcers, including many caused by external medical devices. Sixty‐five per cent (n = 100) of all patients were considered at risk (Braden score ≤ 20) of developing a pressure ulcer. Thirty‐five per cent of patients in the risk group were afflicted with one or more pressure ulcers.

Conclusions.  The prevalence of pressure ulcers in paediatric patients is greater then previously appreciated and the problem requires further exploration. The high percentage of grade 1 pressure ulcers caused by medical devices requires nursing interventions to prevent lesions for these patients.

Relevance to clinical practice.  The high prevalence rate in paediatric patients is disconcerting and requires further exploration in terms of interventions needed to improve outcomes for this patient group.
Teenagers’ perceptions of factors affecting decision‐making competence in the management of type 1 diabetes
Authors: Viklund Gunnel , Wikblad Karin
Published: November 2009

Aims.  Decision‐making is an important prerequisite for empowerment. The aim of this study was to explore teenagers’ perceptions of factors affecting decision‐making competence in diabetes management.

Background.  A previous study that assessed an empowerment programme for teenagers with diabetes showed no effects on metabolic control or empowerment outcomes, which is not in accordance with results from studies on adult diabetes patients. The definition of empowerment highlights the patient’s own responsibility for decision‐making. Earlier studies have shown that many teenagers’ may not be mature in decision‐making competence until late adolescence. To explore the significance of decision‐making competence on the effectiveness of empowerment education we wanted to explore teenagers’ own view on factors affecting this competence.

Design.  An explorative, qualitative interview study was conducted with 31 teenagers with type 1 diabetes, aged 12–17 years.

Methods.  The teenagers were interviewed two weeks after completing an empowerment education programme. The interviews were analysed using qualitative content analysis.

Results.  Five categories stood out as important for decision‐making competence: cognitive maturity, personal qualities, experience, social network and parent involvement. Based on the content in the interviews and the five categories, we made an interpretation and formulated an overall theme: ‘Teenagers deserve respect and support for their short‐comings during the maturity process’.

Conclusion.  Our conclusion is that teenagers deserve respect for their immature decision‐making competence. Decision‐making competence was described as cognitive abilities, personal qualifications and experience. To compensate for the deficiencies the teenagers deserve constructive support from their social network and the essential support is expected to come from their parents.

Relevance to clinical practice.  These findings can be useful for diabetes team members in supporting teenagers with diabetes and their parents both in individual meetings and when planning and delivering group education.
Self‐care behaviour and related factors in older people with Type 2 diabetes
Authors: Bai Yu‐Ling , Chiou Chou‐Ping , Chang Yong‐Yuan
Published: November 2009

Aim.  The present study examined the factors related to self‐care behaviour in type 2 diabetic patients aged ≥65 years. In addition, this study tested the effect of the important explanatory factors on self‐care behaviour.

Background.  Along with the development of an ageing society, diabetes occurs frequently among older people. Diabetes requires continual medical treatment, with patients responsible for self‐care. Although the relationships among social support, depression and self‐care have been widely studied, little is know about older diabetic patients, especially in Taiwan.

Design.  A correlational design was adopted. In total, 165 patients recruited using convenience sampling were diabetic outpatients at three hospitals in southern Taiwan from January–March 2005.

Methods.  The participants were interviewed using the Personal Resource Questionnaire 2000 (PRQ 2000), Diabetes Self‐Care Scale and Taiwan Geriatric Depression Scale (TGDS). Data were analysed using descriptive statistics and multiple regression analysis.

Result.  Self‐care behaviour scores were significantly influenced by different gender, education level, economic status and religious beliefs of older diabetic patients. Depression and self‐care behaviour were negatively correlated. Social support, education and duration of diabetes significantly affected self‐care behaviour, accounting for 35·6% of total variance.

Conclusions.  Social support plays a vital factor in contributing to the facilitation of self‐care behaviour. These analytical findings demonstrate the importance of social support, education and duration of diabetes in determining self‐care behaviour for diabetic older diabetic patients and serve as references for future studies of self‐care behaviour in type 2 older diabetic patients.

Relevance to clinical practice.  Implication for nurses highlights the significance of providing patients with social support that will enable them to have good support systems during their disease treatment to enhance self‐care abilities and improve quality of life.
Mycobacteria isolated from Chesapeake Bay fish
Authors: Stine C B , Kane A S , Baya A M
Published: November 2009

Mycobacteriosis in fish can result in ulcers, emaciation, and in some cases death. Mycobacteria have been previously isolated from a variety of Chesapeake Bay fish species, and the current study was designed to identify potential host specificity and location fidelity of mycobacterial isolates. Mycobacteria were isolated from wild fish of the Chesapeake Bay collected from the Upper Bay, the Choptank River, Herring Bay, the Chicamacomico River, the Pocomoke River and the Potomac River in 2003–2006. Mycobacterial isolates were recovered from striped bass, Morone saxatilis, Atlantic menhaden, Brevoortia tyrannus, white perch, Morone americana, summer flounder, Paralichthys dentatus, spot, Leiostomus xanthurus, largemouth bass, Micropterus salmoides, channel catfish, Ictalurus punctatus, common carp, Cyprinus carpio carpio, spotted seatrout, Cynoscion nebulosus, killifish, Fundulus sp., blueback herring, Alosa aestivalis, American gizzard shad, Dorosoma cepedianum and American silver perch, Bairdiella chrysoura. Twenty‐nine well‐defined mycobacterial groups resulted from gas chromatography dendrogram clustering of isolates. The majority of groups included more than one host species and more than one site of collection. However, four groups contained only striped bass isolates, three of which were similar to M. shottsii. Therefore, multiple Chesapeake Bay fish species are colonized with multiple mycobacterial isolates, of which few appear to be host or location specific.
Translating 5‐HT4receptor pharmacology
Authors: Sanger G. J.
Published: November 2009

Abstract Since metoclopramide was first described (in 1964) there have been several attempts to develop compounds which retained gastrointestinal prokinetic activity (via 5‐HT4receptor activation) but without the limiting side effects associated with dopamine D2receptor antagonism. Early compounds (mosapride, cisapride, renzapride, tegaserod) were identified before several of the 5‐HT receptors were even described (including 5‐HT4and 5‐HT2B), whereas prucalopride came later. Several compounds were hampered by non‐selectivity, introducing cardiac liability (cisapride: activity at human Ether‐a‐go‐go Related Gene) or potentially, a reduced intestinal prokinetic activity caused by activity at a second 5‐HT receptor (renzapride: antagonism at the 5‐HT3receptor; tegaserod: antagonism at the 5‐HT2Breceptor). Poor intrinsic activity at gastrointestinal 5‐HT4receptors has also been an issue (mosapride, tegaserod). Perhaps prucalopride has now achieved the profile of good selectivity of action and high intrinsic activity at intestinal 5‐HT4receptors, without clinically‐meaningful actions on 5‐HT4receptors in the heart. The progress of this compound for treatment of chronic constipation, as well as competitor molecules such as ATI‐7505 and TD‐5108, will now be followed with interest as each attempts to differentiate themselves from each other. Perhaps at last, 5‐HT4receptor agonists are being given the chance to show what they can do.
Enhanced colonization and pathogenicity of Erwinia amylovora strains transformed with the near‐ubiquitous pEA29 plasmid on pear and apple
Authors: Mohammadi M.
Published: November 2009

Three plasmid‐free strains of Erwinia amylovora, the causal agent of fire blight disease of pome trees, one from Iran, one from Egypt and one from Spain, were transformed with the near‐ubiquitous nonconjugative pEA29 plasmid from a wild‐type strain and characterized. The plasmid‐deficient strains were levan‐ and slime‐positive, motile, chemotaxis‐positive, induced HR on Nicotiana tabacum var. xanthi but produced several‐fold less amylovoran and were weakly pathogenic on pear slices and apple seedlings compared to plasmid‐bearing wild‐type strains. When inoculated onto wounded young apple (cv. Royal Gala) leaves, the plasmid‐free strains labelled with green fluorescent protein gene (gfp) were mainly restricted to the inoculation site at the leaf tips, in contrast to the plasmid‐carrying wild‐type strains that moved into the midrib xylem vessel and colonized the adjacent parenchyma cells. Upon introduction of the transposon‐labelled pEA29 plasmid, amylovoran production, degree of oozing and tissue necrosis on pear slices were significantly elevated in all three strains, whilst the levels of levan and levansucrase declined. Only the strains from Iran and Egypt gained the ability to invade and colonize the young apple leaves following the introduction of pEA29. It is concluded that acquisition of the nonconjugative near‐ubiquitous plasmid may not necessarily confer increasing pathogenicity in all bacterial strains.
Effect of temperature on the transmission of Potato mop‐top virus from seed tuber and by its vector, Spongospora subterranea
Authors: Carnegie S. F. , Davey T. , Saddler G. S.
Published: November 2009

Potato mop‐top virus (PMTV) causes disease in both the growing plant and tubers (spraing) of potato and is transmitted by the plasmodiophorid Spongospora subterranea, the cause of powdery scab. The effect of temperature during plant growth on the transmission of PMTV from infected seed tubers and from infested growing media was investigated in a series of glasshouse experiments. Symptoms developed on foliage of plants derived from infected seed tubers but none developed when PMTV was transmitted by S. subterranea in soil. The incidence of foliar symptoms was greatest on plants grown at 12°C, less at 16°C, few at 20°C and absent at 24°C. The transmission of PMTV from infected seed tubers was not significantly affected by temperatures between 12 and 24°C, but when the virus was transmitted by S. subterranea, minimal tuber infection occurred at 24°C and no differences were recorded at temperatures between 12 and 20°C. The incidence of powdery scab on tubers was greatest at 12 and 16°C and very low at 20 and 24°C. However, the incidence and severity of root galling caused by S. subterranea, was greatest at 20 and very low at 24°C. The incidence of powdery scab was greater on tubers of plants derived from infected seed tubers grown in a fluctuating temperature regime of 12 h at 20°C followed by 24 h at 12°C than on those grown at a constant 20°C, whereas the incidence of tuber infection by PMTV and spraing was similar for both regimes. This demonstrates that infection of roots can occur at a higher temperature than that for powdery scab on tubers and that this root infection can enable the transmission of PMTV into the potato plant.
Relationship between the extent of colonization by Verticillium dahliae and symptom expression in strawberry (Fragaria × ananassa) genotypes resistant to verticillium wilt
Authors: Shaw D. V. , Gordon T. R. , Hansen J. , Kirkpatrick S. C.
Published: November 2009

Eleven strawberry (Fragaria × ananassa) genotypes from the University of California breeding programme known to be resistant to verticillium wilt were inoculated with Verticillium dahliae. Individual plants were given a resistance score based on the severity of visual symptoms, and the extent of colonization was quantified as the percentage of petioles not colonized by the pathogen. Both resistance scores and the percentage of pathogen‐free petioles decreased significantly from May to June (P < 0·05) during each of two growing seasons, indicating a progression of both colonization and symptom expression. Even the most resistant genotypes had plants with some infected petioles, and manifested some symptoms of verticillium wilt. Significant (P < 0·05) genotypic variance was detected for the percentage of pathogen‐free petioles, but not for resistance score. The percentage of pathogen‐free petioles had a strongly positive genotypic correlation (rg = 0·77, P < 0·01) with resistance score, indicating that about 60% of the genotypic variation for visual symptoms in this set of resistant genotypes was explained by the extent of colonization of individual plants by V. dahliae. Conversely, the genotypic correlation between the percentage of pathogen‐free petioles and the resistance score for plants sampled in May (rg = 0·74, P < 0·01) was smaller than that for plants harvested in July (rg = 0·93, P < 0·01). Together, these results suggest that the overall performance of strawberry genotypes in the presence of V. dahliae can be enhanced by both resistance and tolerance, but that tolerance may be less stable over the course of a season. Distinguishing between these two mechanisms may require evaluations that supplement visual assessments of resistance.
Expression analysis suggests potential roles of microRNAs for phosphate and arbuscular mycorrhizal signaling in Solanum lycopersicum
Authors: Gu Mian , Xu Ke , Chen Aiqun , Zhu Yiyong , Tang Guiliang , Xu Guohua
Published: November 2009

MicroRNAs (miRNAs) have emerged as a class of gene expression regulators that play crucial roles in many biological processes. Recently, several reports have revealed that micoRNAs participate in regulation of symbiotic interaction between plants and nitrogen‐fixing rhizobia bacteria. However, the role of miRNAs in another type of plant–microbe interaction, arbuscular mycorrhizal (AM) symbiosis, has not been documented. We carried out a microarray screen and poly(A)‐tailed reverse transcriptase‐polymerase chain reaction (RT‐PCR) validation for miRNA expression in tomato (Solanum lycopersicum) under varying phosphate (Pi) availability and AM symbiosis conditions. In roots, miRNA158, miRNA862‐3p, miRNA319, miRNA394 and miR399 were differentially regulated under three different treatments, Pi sufficient (+P ), Pi deficient (−P) and AM symbiosis (+M ). In leaves, up to 14 miRNAs were up‐ or down‐regulated under either or both of the Pi treatments and AM symbiosis, of which miR158, miR319 and miR399 were responsive to the treatments in both roots and leaves. We detected that miR395, miR779.1, miR840 and miR867 in leaves were specifically responsive to AM symbiosis, which is independent of Pi availability, whereas miR398 in leaves and miR399 in both roots and leaves were Pi starvation induced. Furthermore, miR158 in roots as well as miR837‐3p in leaves were responsive to both Pi deprivation and AM colonization. In contrast, miR862‐3p in roots was responsive to Pi nutrition, but not to AM symbiosis. Moreover, the group of miRNA consisting miR319 and miR394 in roots and miR158, miR169g*, miR172, miR172b*, miR319, miR771 and miR775 in leaves were up‐ and down‐regulated by Pi starvation, respectively. The data suggest that altered expression of distinct groups of miRNA is an essential component of Pi starvation‐induced responses and AM symbiosis.
ROS in biotic interactions
Authors: Torres Miguel Angel
Published: November 2009

Production of reactive oxygen species (ROS) is a hallmark of successful recognition of infection and activation of plant defenses. ROS play multifaceted signaling functions mediating the establishment of multiple responses and can act as local toxins. Controversy surrounds the origin of these ROS. Several enzymatic mechanisms, among them a plasma membrane NADPH oxidase and cell wall peroxidases, can be responsible for the ROS detected in the apoplast. However, high levels of ROS from metabolic origins and/or from downregulation of ROS‐scavenging systems can also accumulate in different compartments of the plant cell. This compartmentalization could contribute to the specific functions attributed to ROS. Additionally, ROS interact with other signals and phytohormones, which could explain the variety of different scenarios where ROS signaling plays an important part. Interestingly, pathogens have developed ways to alter ROS accumulation or signaling to modify plant defenses. Although ROS have been mainly associated with pathogen attack, ROS are also detected in other biotic interactions including beneficial symbiotic interactions with bacteria or mycorrhiza, suggesting that ROS production is a common feature of different biotic interactions. Here, we present a comprehensive review describing the newer views in ROS signaling and function during biotic stress.
Gender Differences in the Costs that Subordinate Group Members Impose on Dominant Males in a Cooperative Breeder
Authors: Mitchell Jeremy S. , Jutzeler Eva , Heg Dik , Taborsky Michael
Published: November 2009

In group‐living species, a dominant male’s ability to monopolize reproduction, and the cost of doing so, are expected to vary with a group’s gender composition. We used spawning observations of a group‐living cichlid,Neolamprologus pulcher, to test this expectation. We constructed groups that contained a dominant breeding pair and either two male subordinates, one male and one female subordinate or two female subordinates. Parasitic spawning by male subordinates was more common in groups with two male subordinates than in groups with one male and one female subordinate. Female subordinates were never observed laying eggs in dominant females’ clutches, but three female subordinates laid independent clutches. During spawning, frequencies of dominant male aggression towards male and female subordinates were similar. Dominant males were less aggressive during non‐reproductive periods. The declines were greater for female subordinates, such that, during non‐reproductive periods, dominant males were more aggressive towards male subordinates. Aggression towards each subordinate was also affected by the second subordinate’s gender; the direction of that effect differed for large and small subordinates. Male subordinates approached breeding shelters less often than female subordinates, and both male and female subordinates approached shelters more frequently when the second subordinate was male. Collectively, these patterns suggest: (1) that male subordinates impose higher costs on dominant males than female subordinates do and (2) that the presence of a second male subordinate imposes additional costs beyond those of the first male subordinate. We discuss the implications of these effects for dominant and subordinate group members.
Three‐dimensional ultrasonographic measurements of the fetal lungs for prediction of perinatal outcome in isolated congenital diaphragmatic hernia
Authors: Ruano Rodrigo , Aubry Marie‐Cécile , Barthe Bruno , Dumez Yves , Benachi Alexandra
Published: November 2009

Aim:  To evaluate the potential of different lung measurements using three‐dimensional ultrasonography (3D‐US) to predict perinatal outcome in isolated congenital diaphragmatic hernia (CDH).

Methods:  Twenty‐one fetuses presenting isolated CDH were prospectively evaluated by 3D‐US between January 2002 and November 2003. Observed/expected total, contralateral and ipsilateral fetal lung volume ratios (o/e‐TotFLV, o/e‐ContFLV and o/e‐IpsiFLV, respectively) were calculated using the rotational technique and ultrasonographic fetal total lung volume to bodyweight ratio (USFLW). These lung measurements were compared to each other and to perinatal outcomes: perinatal deaths, severe pulmonary hypoplasia (PH) and pulmonary arterial hypertension (PAH).

Results:  Perinatal death occurred in 11 of the 21 infants (52.4%), severe PH in 14 of 21 infants (66.7%) and PAH in 14 of 20 neonates (70%). Severe PH and PAH occurred simultaneously in 12 of 20 (60%) infants. Good correlations between lung ratios were observed. O/e‐TotFLV, o/e‐IpsiFLV and USFLW correlated statistically with postnatal diagnosis of severe PH, while only o/e‐TotFLH correlated statistically with postnatal diagnosis of PAH. The accuracies of o/e‐TotFLV, o/e‐ContFLV, o/e‐IpsiFLV and USFLW in predicting perinatal deaths were 85.7, 76.2, 66.7 and 76.2%, respectively.

Conclusion:  O/e‐TotFLV using 3D‐US appears to be the most accurate predictor of perinatal mortality because it can predict both PH and PAH.
Expression of aquaporin 8 is diversely regulated by osmotic stress in amnion epithelial cells
Authors: Qi Hongbo , Li Li , Zong Wenjun , Hyer Barb J. , Huang Jin
Published: November 2009

Aim:  Water absorption across fetal chorioamniotic membranes is a critical regulatory pathway for amniotic fluid volume homeostasis. Aquaporin 8 (AQP8) is a water channel regulating osmotic water travel across membranes. This study was to investigate the distribution and expression of AQP8 in amnion epithelial cells (AEC) in response to different osmotic stresses.

Methods:  Cells derived from the amnion were subjected to different osmotic culture media. Reverse transcriptase–polymerase chain reaction, Western blotting and immunofluorescence analysis were used to determine expression and localization of AQP8.

Results:  Immunofluorescent staining confirmed the expression of AQP8 on cytomembrane and in cytoplasm. Hypotonic media increased AQP8 on cytomembrane of AEC. Compared to isosmolar media, hypotonic media significantly enhanced AQP8 mRNA and protein expression (P < 0.05), while hypertonic media significantly decreased expression (P < 0.05).

Conclusion:  The expression and distribution of AQP8 in AEC are diversely regulated by osmotic loads suggesting a role for AQP8 in intramembranous water transport and the balance of amniotic fluid.