bluuebunny/crossref_metadata_2025 huggingface dataset:
Making habitable space together with female Chinese immigrants to Hong Kong
Authors: Kwok Jackie Yan-chi , Ku Hok-Bun
Published: August 2008

When women from mainland China are newly arrived in Hong Kong, their first difficulty is usually environmental stress. Their socio-economic situation often limits their ability to express their expectations related to their living space. In order to enable the women to voice their views and become participants in urban planning, our research group adopted interdisciplinary participatory action research, including non-participant observation, in-depth interviews, focus groups, photovoice, visual simulation-modelling workshops, etc. In the process, we asked these newly arrived woman to 1) offer comments on their current living situation; 2) describe clearly their preferred housing environment; and 3) propose suggestions to the Hong Kong Government in respect to housing and neighbourhood planning. This article intends to demonstrate the validity of the use of these methods to promote participatory democracy in the context of an urban living environment.
Teaching and learning action research
Authors: Kur Ed , DePorres Daphne , Westrup Nancy
Published: August 2008

This article describes our experience teaching action research (AR) in a Mexican graduate program. It emphasizes the challenges associated with teaching this kind of research in Mexico and illustrates ways we address those challenges. It also illustrates that a high level of personal growth often accompanies AR training and that such growth, as well as learning the `mechanics' of AR, is significantly enhanced when faculty become deeply engaged with students during the entire learning experience. The article contributes to what is known about teaching action research in graduate university settings, specifically, about how to teach it, reasons for teaching it, and unintended consequences of teaching it. It describes problems in teaching and mastering AR competence and uses experiences in Latin America's oldest masters program in organization development to illustrate solutions. Examples from student projects demonstrate how action research coursework translates to increased student skills and simultaneously to increased effectiveness of the social systems in which the students conduct research. Finally, the article describes work that led a university to include action research training in all of its graduate programs.
Effects of Parent Instruction on Communicative Turns of Latino Children Using Augmentative and Alternative Communication During Storybook Reading
Authors: Iris Rosa-Lugo Linda , Kent-Walsh Jennifer
Published: August 2008

Current research indicates that children who use augmentative and alternative communication (AAC) often are not given opportunities to participate in supportive early storybook-reading experiences in home environments. This investigation employed a single-subject, multiple-baseline-across-subjects design to investigate the effects of a parent instructional program on the communication of two participating Latino parents and their Latino children using AAC (ages = 6 years 8 months and 6 years 10 months). Both parents reached criterion for implementation of the targeted interaction strategy during storybook reading and evidenced generalized and maintained strategy use. In addition, both participating children demonstrated robust increases in communicative turns taken and novel semantic concepts expressed.
Direction Versus Proximity
Authors: Claassen Ryan L.
Published: August 2008

Scale limitations, endogeneity problems, and observational equivalence in observational studies render many tests of the proximity and directional models inconclusive. Fortunately, the task of designing experimental tests has proven tractable and the small, but growing, body of experimental evidence sheds new light on directional and proximity motivated behavior. The experiment described in this article was designed to reexamine the role of ideology structuring candidate evaluations in the general population and test the models in two new policy areas: opinion about military spending and opinion about abortion. The results indicate that ideology and opinions about military spending stimulate proximity behavior whereas opinions about abortion stimulate directional behavior. It is also found that abortion-based evaluations are more strongly directional for those who oppose abortion—which is consistent with the notion of policy balancing. The article concludes by considering the possibility that some issues lend themselves to proximity comparisons whereas others lend themselves to directional comparisons and discussing the implications for democratic politics.
Understanding the Press Imaging of `Terrorist'
Authors: de Nelson Sonia Ambrosio
Published: August 2008

/ Media is at the heart of many public debates in the same way as terrorism and Islam are part of a global discourse since the events of 9/11 in the United States. This article attempts to use the social construction of social problems approach to understand the media's imaging of `terrorists' in the context of Singapore. Combining media research with social critical reflection provides the tools to identify the social rationale dimension. The application of such a procedure reveals the complex relationships between the media and their role in the process of `nationbuilding'. The city-state fits the order model of society, where social integration, order and stability are fundamental. The Singaporean population is predominantly non-Islamic Chinese; however, geographically Singapore is located between Malaysia, a Muslim country, and Indonesia, where 89 percent of the population are Muslims. The article looks at Singapore's mainstream English-language newspaper, The Straits Times , and its representation of terrorists following the events of 9/11. The data cover three periods: (1) immediately after 9/11; (2) between January and February 2002, when a group of men accused of `terrorism-related activities' were arrested in Singapore; and (3) September 2002, when Singapore's authorities announced the arrest of a second group of `suspect terrorists'.
Former Yugoslavia On the World Wide Web
Authors: Volcic Zala
Published: August 2008

/ Since the violent collapse of former Yugoslavia, the `new' nation-states of Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Kosovo, Montenegro and Macedonia have attempted to position themselves on the global map while seeking to create a distinctive `brand' (national) identity. Drawing on a textual analysis of their official governmental websites, this article explores how these former Yugoslav states use the Internet to create and represent self-images for the world. The governmental websites analysed frame the nation as a `brand' in that they employ advertising mechanisms to promote and sell their nations. Websites represent national territories, histories, products and citizens as commodities that can be sold to foreign investors and tourists. In this way, the former Yugoslav countries are transformed into brand-states that serve the function of relegating their citizens to the role of either exotic Others ready to be consumed by rich western tourists, or goods for foreign investment.
Monitoring oral antiplatelet therapy: is it justified?
Authors: Ang Lawrence , Mahmud Ehtisham
Published: August 2008

Platelets play a key role in the initial formation and progression of intravascular thrombus. During coronary and peripheral vascular interventions, antiplatelet therapy is used to impair platelet reactivity in order to minimize adverse ischemic events. Chronic antiplatelet therapy is also administered to decrease the long term risk of major adverse cardiovascular events in patients with high atherothrombotic burden. However, due to a heterogeneous response to antiplatelet agents, a substantial number of patients with cardiovascular disease remain at risk despite adherence to therapy. Since the availability of point-of-care rapid platelet function assays, quick and reproducible evaluation of platelet function after the administration of aspirin, thienopyridines, and glycoprotein IIb/IIIa inhibitors is possible. Various definitions of suboptimal platelet inhibition with oral antiplatelet therapy and associated risk factors are presented here. An algorithm to guide optimal antiplatelet therapy based on rapid platelet function testing during cardiovascular interventions is also presented.
Review: Hypercholesterolemia-associated endothelial progenitor cell dysfunction
Authors: Pirro Matteo , Bagaglia Francesco , Paoletti Lucio , Razzi Rolando , Mannarino Massimo R.
Published: August 2008

Hypercholesterolemia has been associated with increased cardiovascular risk by contributing to mechanical endothelial injury and dysfunction. There is evidence that chronic exposure to increased plasma cholesterol levels might also impair the repair of lipoprotein-mediated endothelial injury, possibly by reducing the availability and function of circulating endothelial progenitors. This review summarizes current knowledge about the mechanisms of lipoprotein-mediated endothelial injury and endothelial progenitor cell assisted vascular repair; the influence of hypercholesterolemia on endothelial progenitor cell dysfunction will be also addressed.
Mechanisms of alcoholic heart disease
Authors: Ren Jun , Wold Loren E.
Published: August 2008

Compromised heart function is regularly seen in patients with chronic alcohol ingestion and is often manifested as cardiomegaly, reduced myocardial contractility (with concomitant reductions in ejection fraction and stroke volume), myocardial fibrosis, enhanced risk of stroke and hypertension, and disruptions in the myofibrillary structure. A number of mechanisms including oxidative damage, deposition of triglycerides, altered fatty acid extraction, decreased myofilament Ca2+sensitivity, and impaired protein synthesis have been proposed for the development of alcoholic cardiomyopathy. Nonetheless, the underlying mechanism(s) has not been delineated. Several alcohol metabolites have been identified as specific toxins of myocardial tissue, including ethanol, its first and major metabolic product — acetaldehyde — and fatty acid ethyl esters. Acetaldehyde directly impairs cardiac contractile function, disrupts cardiac excitation—contraction coupling and promotes oxidative damage and lipid peroxidation. Unfortunately, the most direct approach to studying this (direct administration of acetaldehyde) is impossible, since direct intake of acetaldehyde is highly toxic and unsuitable for chronic studies. In order to overcome this obstacle, transgenic mice have recently been produced to artificially alter ethanol/acetaldehyde metabolism, resulting in elevated acetaldehyde levels after ethanol ingestion. This review will summarize some of the postulated mechanisms for alcoholic cardiomyopathy, with special emphasis on animal models.
Effects of alcohol on atrial fibrillation: myths and truths
Authors: Balbão Carlos E.B. , de Paola Angelo A.V. , Fenelon Guilherme
Published: August 2008

Alcohol is the most consumed drug worldwide. Both acute and chronic alcohol use have been associated with cardiac arrhythmias, in particular atrial fibrillation, or so-called 'holiday heart syndrome'. Epidemiological, clinical and experimental studies have attempted to elucidate the mechanisms involved in this association. However, because most of these studies have shown conflicting results, the connection between ethanol and atrial arrhythmias remains controversial. Historical, epidemiological and pharmacological aspects of alcohol, as well as recent concepts on atrial fibrillation are reviewed. We then examine the literature and provide a critical point of view on the still elusive association between alcohol and atrial fibrillation.
Results of the Cord Blood Transplantation Study (COBLT): clinical outcomes of unrelated donor umbilical cord blood transplantation in pediatric patients with hematologic malignancies
Authors: Kurtzberg Joanne , Prasad Vinod K. , Carter Shelly L. , Wagner John E. , Baxter-Lowe Lee Ann , Wall Donna , Kapoor Neena , Guinan Eva C. , Feig Stephen A. , Wagner Elizabeth L. , Kernan Nancy A.
Published: August 2008

Outcomes of unrelated donor cord blood transplantation in 191 hematologic malignancy children (median age, 7.7 years; median weight, 25.9 kg) enrolled between 1999 and 2003 were studied (median follow-up, 27.4 months) in a prospective phase 2 multicenter trial. Human leukocyte antigen (HLA) matching at enrollment was 6/6 (n = 17), 5/6 (n = 58), 4/6 (n = 111), or 3/6 (n = 5) by low-resolution HLA-A, -B, and high-resolution (HR) DRB1. Retrospectively, 179 pairs were HLA typed by HR. The median precryopreservation total nucleated cell (TNC) dose was 5.1 × 107 TNC/kg (range, 1.5-23.7) with 3.9 × 107 TNC/kg (range, 0.8-22.8) infused. The median time to engraftment (absolute neutrophil count > 500/mm3 and platelets 50 000/μL) was 27 and 174 days. The cumulative incidence of neutrophil engraftment by day 42 was 79.9% (95% confidence interval [CI], 75.1%-85.2%); acute grades III/IV GVHD by day 100 was 19.5% (95% CI, 13.9%-25.5%); and chronic GVHD at 2 years was 20.8% (95% CI, 14.8%-27.7%). HR matching decreased the probability of severe acute GVHD. The cumulative incidence of relapse at 2 years was 19.9% (95% CI, 14.8%-25.7%). The probabilities of 6-month and 2-year survivals were 67.4% and 49.5%. Unrelated donor cord blood transplantation from partially HLA-mismatched units can cure many children with leukemias. The study was registered at www.clinicaltrials.gov as #NCT00000603.
Plasmin therapy enhances mobilization of HPCs after G-CSF
Authors: Tjwa Marc , Janssens Stefan , Carmeliet Peter
Published: August 2008

The role of proteinases in the mobilization of hematopoietic progenitor cells (HPCs) after granulocyte colony-stimulating factor (G-CSF) remains unclear. Here we report that genetic loss of the plasminogen activator inhibitor Pai-1 or of the plasmin inhibitor α2-antiplasmin increases HPC mobilization in response to G-CSF. Moreover, thrombolytic agents, such as tenecteplase and microplasmin, enhance HPC mobilization in mice and humans. Taken together, these findings identify a novel role for plasmin in augmenting HPC mobilization in response to G-CSF.
Interaction between polymorphisms of the Human Leukocyte Antigen and HPV-16 Variants on the risk of invasive cervical cancer
Authors: de Araujo Souza Patricia S , Maciag Paulo C , Ribeiro Karina B , Petzl-Erler Maria Luiza , Franco Eduardo L , Villa Luisa L
Published: August 2008

Background

Persistent infection with oncogenic types of human papillomavirus (HPV) is the major risk factor for invasive cervical cancer (ICC), and non-European variants of HPV-16 are associated with an increased risk of persistence and ICC. HLA class II polymorphisms are also associated with genetic susceptibility to ICC. Our aim is to verify if these associations are influenced by HPV-16 variability.

Methods

We characterized HPV-16 variants by PCR in 107 ICC cases, which were typed forHLA-DQA1,DRB1andDQB1genes and compared to 257 controls. We measured the magnitude of associations by logistic regression analysis.

Results

European (E), Asian-American (AA) and African (Af) variants were identified. Here we show that inverse association betweenDQB1*05(adjusted odds ratio [OR] = 0.66; 95% confidence interval [CI]: 0.39–1.12]) and HPV-16 positive ICC in our previous report was mostly attributable to AA variant carriers (OR = 0.27; 95%CI: 0.10–0.75). We observed similar proportions ofHLA DRB1*1302carriers in E-P positive cases and controls, but interestingly, this allele was not found in AA cases (p = 0.03, Fisher exact test). A positive association withDRB1*15was observed in both groups of women harboring either E (OR = 2.99; 95% CI: 1.13–7.86) or AA variants (OR = 2.34; 95% CI: 1.00–5.46). There was an inverse association betweenDRB1*04and ICC among women with HPV-16 carrying the 350T [83L] single nucleotide polymorphism in theE6gene (OR = 0.27; 95% CI: 0.08–0.96). An inverse association betweenDQB1*05and cases carrying 350G (83V) variants was also found (OR = 0.37; 95% CI: 0.15–0.89).

Conclusion

Our results suggest that the association between HLA polymorphism and risk of ICC might be influenced by the distribution of HPV-16 variants.
Some peace of mind: assessing a pilot intervention to promote mental health among widows of injecting drug users in north-east India
Authors: Kermode Michelle , Devine Alexandra , Chandra Prabha , Dzuvichu Bernice , Gilbert Thomhood , Herrman Helen
Published: August 2008

Background

HIV prevalence in north-east India is high and injecting drug use (IDU) is common. Due to HIV-related deaths there are increasing numbers of IDU widows, many of whom are HIV infected, and experiencing poor health, social isolation, discrimination and poverty, all factors likely to be compromising their mental health. There is increasing recognition of the links between HIV and mental health.

Methods

The aim of this study was to pilot a peer-facilitated, participatory action group (PAG) process and assess the impact of the intervention on the mental health of participants. The intervention consisted of 10 PAG meetings involving 74 IDU widows. Changes in quality of life (WHOQOL-BREF), mental health (GHQ12) and somatic symptoms were assessed. The value of the intervention from the perspective of the participants was captured using a qualitative evaluation method (Most Significant Change).

Results

Participants' quality of life, mental health and experience of somatic symptoms improved significantly over the course of the intervention, and the women told stories reflecting a range of 'significant changes'.

Conclusion

This pilot intervention study demonstrated that a participatory approach to mental health promotion can have a positive impact on the lives of vulnerable women, and the potential to contribute to HIV prevention. Further investigation is warranted.
Evolution of developmental roles of Pax2/5/8paralogs after independent duplication in urochordate and vertebrate lineages
Authors: Bassham Susan , Cañestro Cristian , Postlethwait John H
Published: August 2008

Background

Gene duplication provides opportunities for lineage diversification and evolution of developmental novelties. Duplicated genes generally either disappear by accumulation of mutations (nonfunctionalization), or are preserved either by the origin of positively selected functions in one or both duplicates (neofunctionalization), or by the partitioning of original gene subfunctions between the duplicates (subfunctionalization). The Pax2/5/8 family of important developmental regulators has undergone parallel expansion among chordate groups. After the divergence of urochordate and vertebrate lineages, two rounds of independent gene duplications resulted in thePax2, Pax5, andPax8genes of most vertebrates (the sister group of the urochordates), and an additional duplication provided thepax2aandpax2bduplicates in teleost fish. Separate from the vertebrate genome expansions, a duplication also created twoPax2/5/8genes in the common ancestor of ascidian and larvacean urochordates.

Results

To better understand mechanisms underlying the evolution of duplicated genes, we investigated, in the larvacean urochordateOikopleura dioica, the embryonic gene expression patterns ofPax2/5/8paralogs. We compared the larvacean and ascidian expression patterns to infer modular subfunctions present in the single pre-duplicationPax2/5/8gene of stem urochordates, and we compared vertebrate and urochordate expression to infer the suite ofPax2/5/8gene subfunctions in the common ancestor of olfactores (vertebrates + urochordates). Expression pattern differences of larvacean and ascidian Pax2/5/8 orthologs in the endostyle, pharynx and hindgut suggest that some ancestral gene functions have been partitioned differently to the duplicates in the two urochordate lineages. Novel expression in the larvacean heart may have resulted from the neofunctionalization of aPax2/5/8gene in the urochordates. Expression of larvaceanPax2/5/8in the endostyle, in sites of epithelial remodeling, and in sensory tissues evokes like functions ofPax2,Pax5andPax8in vertebrate embryos, and may indicate ancient origins for these functions in the chordate common ancestor.

Conclusion

Comparative analysis of expression patterns of chordate Pax2/5/8 duplicates, rooted on the single-copyPax2/5/8gene of amphioxus, whose lineage diverged basally among chordates, provides new insights into the evolution and development of the heart, thyroid, pharynx, stomodeum and placodes in chordates; supports the controversial conclusion that the atrial siphon of ascidians and the otic placode in vertebrates are homologous; and backs the notion thatPax2/5/8functioned in ancestral chordates to engineer epithelial fusions and perforations, including gill slit openings.
Conjugated linoleic acid modulation of risk factors associated with atherosclerosis
Authors: Nakamura Yukiko K , Flintoff-Dye Nichole , Omaye Stanley T
Published: August 2008

Conjugated linoleic acid (CLA) has been the subject of extensive investigation regarding its possible benefits on a variety of human diseases. In some animal studies, CLA has been shown to have a beneficial effect on sclerotic lesions associated with atherosclerosis, be a possible anti-carcinogen, increase feed efficiency, and act as a lean body mass supplement. However, the results have been inconsistent, and the effects of CLA on atherogenesis appear to be dose-, isomer-, tissue-, and species-specific. Similarly, CLA trials in humans have resulted in conflicting findings. Both the human and animal study results may be attributed to contrasting doses of CLA, isomers, the coexistence of other dietary fatty acids, length of study, and inter-and/or intra-species diversities. Recent research advances have suggested the importance of CLA isomers in modulating gene expression involved in oxidative damage, fatty acid metabolism, immune/inflammatory responses, and ultimately atherosclerosis. Although the possible mechanisms of action of CLA have been suggested, they have yet to be determined.
Primary squamous cell carcinoma of lung in a 13-year-old boy: a case report
Authors: Wang Jeff F , wang Bo , Jansen Joshua A , Santos Eric E , Sarma Deba P
Published: August 2008

We are reporting a very rare case of primary bronchogenic squamous cell carcinoma (SCC) with bone metastasis in a 13-year-old boy. A brief review of the English literature on this rare neoplasm in childhood is presented.
Raised intrathecal levels of APRIL and BAFF in patients with systemic lupus erythematosus: relationship to neuropsychiatric symptoms
Authors: George-Chandy Annie , Trysberg Estelle , Eriksson Kristina
Published: August 2008

Introduction

The tumour necrosis factor (TNF) family ligands BAFF (B-cell activating factor of TNF family) and APRIL (a proliferation-inducing ligand) are essential for B-cell survival and function. Elevated serum levels of BAFF and APRIL have been reported earlier in patients with systemic lupus erythematosus (SLE). Since autoantibody formation in the central nervous system (CNS) is a distinct feature of neuropsychiatric SLE (NPSLE), we have investigated whether NPSLE is associated with an enhanced intrathecal production of APRIL and BAFF.

Methods

Levels of BAFF and APRIL in cerebrospinal fluid (CSF) and serum from healthy controls, SLE patients without CNS involvement, and patients with NPSLE were determined by enzyme-linked immunosorbent assay. Interleukin-6 (IL-6) levels were determined by an IL-6-specific bioassay.

Results

SLE patients had levels of APRIL in CSF that were more than 20-fold higher and levels of BAFF in CSF that were more than 200-fold higher than those of healthy controls. Separate analyses of SLE patients with and without CNS involvement revealed that NPSLE patients had enhanced levels of APRIL in CSF. BAFF and APRIL were likely produced locally in the CNS as CSF and serum levels did not correlate. Moreover, CSF levels of APRIL correlated with BAFF but not with IL-6, suggesting that APRIL and BAFF in the CNS are regulated together but that they are produced independently of IL-6.

Conclusion

To our knowledge this is the first study to show elevated levels of BAFF and APRIL in CSF of SLE patients. APRIL was augmented in NPSLE patients compared with SLE patients without CNS involvement. APRIL and BAFF antagonists breeching the blood-brain barrier therefore could have beneficial effects on SLE patients, in particular patients with NPSLE.
Estrogen Actions in the Male Reproductive System Involve Estrogen Response Element-Independent Pathways
Authors: Weiss Jeffrey , Bernhardt Miranda L. , Laronda Monica M. , Hurley Lisa A. , Glidewell-Kenney Christine , Pillai Suresh , Tong Minghan , Korach Kenneth S. , Jameson J. Larry
Published: August 2008

The estrogen receptor-α (ERα) acts through multiple pathways, including estrogen response element (ERE)-dependent (classical) and ERE-independent (nonclassical) mechanisms. We previously created a mouse model harboring a two-amino-acid mutation of the DNA-binding domain (E207A, G208A) that precludes direct binding of ERα to an ERE. After crossing heterozygous mutant mice with an ERα knockout (ERKO) line, it was possible to assess the degree of physiological rescue by the isolated ERα nonclassical allele (−/AA; AA) when compared with ERKO mice (−/−) and to wild type (+/+; WT). In male ERKO mice up to 8 months of age, testosterone levels were high, although LH levels were similar to WT. Testosterone was normal in the AA mice, indicating that the AA allele rescues the enhanced testosterone biosynthesis in ERKO mice. Male ERKO mice exhibited distention of the seminiferous tubules as early as 2–3 months of age as a consequence of decreased water resorption in the efferent ducts. By 3–4 months of age, ERKO mice had impaired spermatogenesis in approximately 40% of their tubules, and sperm counts and motility declined in association with the histological changes. In the AA mice, histological defects were greatly reduced or absent, and sperm counts and motility were rescued. Levels of aquaporins 1 and 9, which contribute to water uptake in the efferent ducts, were reduced in ERKO mice and partially or fully rescued in AA mice, whereas another water transporter, sodium-hydrogen exchanger-3, was decreased in both ERKO and AA mice. We conclude that non-ERE-dependent estrogen pathways are sufficient to rescue the defective spermatogenesis observed in ERKO mice and play a prominent role in ERα action in the testis, including pathways that regulate water resorption and androgen biosynthesis.
β-Adrenergic Receptor Mediated Protection against Doxorubicin-Induced Apoptosis in Cardiomyocytes: The Impact of High Ambient Glucose
Authors: Yano Naohiro , Suzuki Daisuke , Endoh Masayuki , Tseng Andy , Stabila Joan P. , McGonnigal Bethany G. , Zhao Ting C. , Padbury James F. , Tseng Yi-Tang
Published: August 2008

Recent studies have demonstrated that the β2-adrenergic receptor (β2AR)-Gαi signaling pathway exerts a cardiac antiapoptotic effect. The goals of this study were to determine the intracellular signaling factors involved in β2AR-mediated protection against doxorubicin-induced apoptosis in H9c2 cardiomyocyte and explore the impact of high ambient glucose on the antiapoptotic effect. Under physiological glucose environment (100 mg/dl), β2AR stimulation prevented doxorubicin-induced apoptosis, which was attenuated by cotreatment with wortmannin, a phosphoinositide 3-kinase (PI3K) inhibitor, or transfection of a dominant-negative Akt. Inhibition of Src kinase with 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d] pyrimidine or cSrc small interfering RNA 32 also attenuated the antiapoptotic effect. Inhibition of platelet-derived growth factor receptor (PDGFR) with AG1296 reversed the β2AR-induced antiapoptotic effect. Transfection of an active Src cDNA (Y529F) alone was sufficient to render the cells resistant to apoptosis, and the resistance was blocked by wortmannin. Transfection of an active PI3K minigene (iSH2-p110) alone also induced resistance to apoptosis, and the resistance was reversed by an Akt-inhibitor but not by AG1296. High ambient glucose (450 mg/dl) caused two major effects: 1) it significantly reduced βAR-induced PDGFR phosphorylation, Src kinase activity, and activation of PI3K signaling pathway; and 2) it partially attenuated β2AR-induced antiapoptotic effect. These data provide in vitro evidence supporting a signaling cascade by which β2AR exerts a protective effect against doxorubicin-induced apoptosis via sequential involvement of Gαi, Gβγ, Src, PDGFR, PI3K, and Akt. High ambient glucose significantly attenuates β2AR-mediated cardioprotection by suppressing factors involved in this cascade including PDGFR, Src, and PI3K/Akt.
Mice Lacking the Thyroid Hormone Receptor-α Gene Spend More Energy in Thermogenesis, Burn More Fat, and Are Less Sensitive to High-Fat Diet-Induced Obesity
Authors: Pelletier Paula , Gauthier Karine , Sideleva Olga , Samarut Jacques , Silva J. Enrique
Published: August 2008

Unable to activate brown adipose tissue (BAT) thermogenesis, αT3-receptor-deficient mice (Thra-0/0) are cold intolerant. Our objective was to investigate the impact on energy economy and mechanisms of the alternate facultative thermogenesis developed. Energy expenditure (oxygen and food consumption) is elevated in Thra-0/0 mice reared at room temperature. Such difference disappears at thermoneutrality (30 C) and expands as ambient temperature becomes colder (P < 0.001). Despite eating more, Thra-0/0 are leaner than wild-type (WT) mice (P < 0.01), whereas these, whether on chow or high-fat diet, gained more weight (g/d: 0.12 ± 0.002 vs. 0.08 ± 0.002 and 0.25 ± 0.005 vs. 0.17 ± 0.005, respectively) and adiposity than Thra-0/0 mice (P < 0.001). The respiratory quotient was lower in Thra-0/0 than WT mice (P < 0.001), after feeding or fasted, on chow or high-fat diet, indicating a preference for fat as fuel, which was associated with increased lipoprotein lipase (LPL) expression in skeletal muscle of Thra-0/0 mice but with no differences in gene expression in white adipose tissue. Type-2 deiodinase (D2) was increased in BAT and aerobic muscle of Thra-0/0 mice. This and liver D1 were increased by a high-fat diet in both genotypes, as also were serum T3 and T3/T4 ratio, but more in Thra-0/0 than WT mice (P < 0.001). Remarkably, when studied at thermoneutrality, genotype differences in weight and adiposity gain, respiratory quotient, D2, and LPL disappeared. Thus, disruption of BAT thermogenesis in Thra-0/0 mice activates an alternate facultative thermogenesis that is more energy demanding and associated with reduced fuel efficiency, leanness, increased capacity to oxidize fat, and relative resistance to diet-induced obesity, in all of which muscle LPL and deiodinases play a key role.
Insulin-Like Growth Factors in the Peripheral Nervous System
Authors: Sullivan Kelli A. , Kim Bhumsoo , Feldman Eva L.
Published: August 2008

IGF-I and -II are potent neuronal mitogens and survival factors. The actions of IGF-I and -II are mediated via the type I IGF receptor (IGF-IR) and IGF binding proteins regulate the bioavailability of the IGFs. Cell viability correlates with IGF-IR expression and intact IGF-I/IGF-IR signaling pathways, including activation of MAPK/phosphatidylinositol-3 kinase. The expression of IGF-I and -II, IGF-IR, and IGF binding proteins are developmentally regulated in the central and peripheral nervous system. IGF-I therapy demonstrates mixed therapeutic results in the treatment of peripheral nerve injury, neuropathy, and motor neuron diseases such as amyotrophic lateral sclerosis. In this review we discuss the role of IGFs during peripheral nervous system development and the IGF signaling system as the potential therapeutic target for the treatment of nerve injury and motor neuron diseases.
Hydrogen sulfide and oxygen sensing: implications in cardiorespiratory control
Authors: Olson Kenneth R.
Published: August 2008

Although all cells are variously affected by oxygen, a few have the responsibility of monitoring oxygen tensions and initiating key homeostatic responses when PO2 falls to critical levels. These `oxygen-sensing' cells include the chemoreceptors in the gills(neuroepithelial cells), airways (neuroepithelial bodies) and vasculature(carotid bodies) that initiate cardiorespiratory reflexes, oxygen sensitive chromaffin cells associated with systemic veins or adrenal glands that regulate the rate of catecholamine secretion, and vascular smooth muscle cells capable of increasing blood flow to systemic tissues, or decreasing it through the lungs. In spite of intense research, and enormous clinical applicability,there is little, if any, consensus regarding the mechanism of how these cells sense oxygen and transduce this into the appropriate physiological response. We have recently proposed that the metabolism of hydrogen sulfide(H2S) may serve as an `oxygen sensor' in vertebrate vascular smooth muscle and preliminary evidence suggests it has similar activity in gill chemoreceptors. In this proposed mechanism, the cellular concentration of H2S is determined by the simple balance between constitutive H2S production in the cytoplasm and H2S oxidation in the mitochondria; when tissue oxygen levels fall the rate of H2S oxidation decreases and the concentration of biologically active H2S in the tissue increases. This commentary briefly describes the oxygen-sensitive tissues in fish and mammals, delineates the current hypotheses of oxygen sensing by these tissues, and then critically evaluates the evidence for H2S metabolism in oxygen sensing.
The scaling of safety factor in spider draglines
Authors: Ortlepp Christine , Gosline John M.
Published: August 2008

This study documents the effect of body mass on the size and strength of draglines produced by the orb-weaving spider Araneus diadematus and the jumping spider Salticus scenicus. Silk samples obtained from individuals spanning the range from first-instar juveniles to gravid adults were tested to determine both the properties of the silk material and the strength and static safety factor of the draglines produced by each individual spider. Analysis of material properties indicates that the tensile strength and extensibility of the silks employed by each species are identical over the entire size range of the species. Analysis of the breaking forces for individual draglines, however, indicates that the draglines scale allometrically with the spider's body mass. For Araneus, breaking force (N) scales with body mass (kg) as Fmax=11.2M0.786, and the static safety factor(SBW=Fmax/Mg) scales as SBW=1.14M–0.214. For Salticus, Fmax=0.363M0.66 and SBW=0.037M–0.34. Thus, static safety factors decrease as these spiders grow, with values falling to 4–6 for adult Araneus and to 1–2 for adult Salticus. Analysis of these results suggests that the safety lines produced by these two species are not able to absorb the impact energy of most falls with a fixed length of pre-existing silk, except in the smallest of the Araneus spiders. It is therefore likely that both spiders must draw new silk from their spinnerets during falls to keep the dynamic loads on their safety-lines below failure levels.
Antennule morphology and flicking kinematics facilitate odor sampling by the spiny lobster, Panulirus argus
Authors: Reidenbach Matthew A. , George Nicole , Koehl M. A. R.
Published: August 2008

Many arthropod olfactory appendages bear arrays of hair-like chemosensory sensillae. Odor molecules in the fluid around the animal must reach the surfaces of those hairs to be sensed. We used the lateral flagellum of the olfactory antennule of the spiny lobster, Panulirus argus, as a system to study how the morphology, orientation, and motion of sensilla-bearing appendages affects the small-scale water flow within the hair array. We tested whether antennule flicking enables lobsters to take discrete odor samples by measuring flow fields through an aesthetasc array on a dynamically scaled physical model of a P. argus antennule. Particle image velocimetry revealed that the magnitude and duration of velocity through the aesthetasc array during the rapid flick downstroke is just enough to allow complete replacement of the fluid entrained within the hair array. The complex zig-zag arrangement of aesthetascs hairs, combined with their offset orientation along the antennule, generates flow velocities that are uniform along the length of the hairs. This increases fluid exchange during the flick and reduces the boundary layer thickness surrounding the hairs. The return stroke occurs at about a quarter the speed of the flick, but the velocity of the fluid between the aesthetascs is approximately 25 times slower. The retained fluid during the return stroke remains virtually unstirred and sufficient time occurs for odor molecules to diffuse to aesthetasc surfaces.
Metabolic and molecular stress responses of sublittoral bearded horse musselModiolus barbatusto warming sea water: implications for vertical zonation
Authors: Anestis Andreas , Pörtner Hans O. , Lazou Antigone , Michaelidis Basile
Published: August 2008

The present study set out to investigate the thermal limits of the Mediterranean bivalve Modiolus barbatus, acclimated to various temperatures, and includes a comparison of laboratory determined limits with its temperature-dependent restriction to deeper water layers in its natural habitat. Thermal responses and limits were determined by integrating information from various levels of biological organization, including the expression of Hsp70 and Hsp90, the phosphorylation of stress-activated protein kinases, p38 mitogen-activated protein kinase (p38 MAPK) and cJun-N-terminal kinases (JNKs) as well as metabolic adjustments. The latter were assessed by examining temperature effects on the activity of the key glycolytic enzyme pyruvate kinase (PK). The expression of Hsp70 and Hsp90 was activated when mussels were acclimated to temperatures above 20°C. Increased phosphorylation of p38 MAPK and JNKs at about the same temperatures indicate activation of MAPK signaling cascades and their potential involvement in the induction of Hsp genes. As indicated by the activity of PK, Modiolus barbatus maintains some aerobic capacity when acclimated to temperatures up to 24°C, while further warming probably caused metabolic depression and a shift from aerobic to anaerobic metabolism. An increase in mortality occurred in parallel, during acclimation to temperatures above 24°C. Our results indicate that both the biochemical stress indicators and metabolic status respond in parallel once hypoxemia becomes extreme. Comparison with our previous study of thermal limits and vertical distribution in M. galloprovincialis dwelling in shallow waters emphasizes the relevance of maintained aerobic scope over that of passive tolerance for permanent vertical zonation at higher temperatures in the field. These findings and conclusions are in line with the concept of oxygen and capacity limited thermal tolerance and the associated systemic to molecular hierarchy of thermal limitation.
Reversed functional topology in the antennal lobe of the male European corn borer
Authors: Kárpáti Zsolt , Dekker Teun , Hansson Bill S.
Published: August 2008

The European corn borer Ostrinia nubilalis (Hübner) is a model of evolution of sexual communication in insects. Two pheromone strains produce and respond to opposite ratios of the two pheromone components, Z11 and E11-tetradecenylacetate. The Z-strain uses a ratio of 97:3 of Z11:E11 tetradecenylacetate, whereas the E-strain uses a ratio of 1:99. We studied how the difference in male preference correlates with differences in wiring of olfactory input and output neurons in the antennal lobe (AL). Activity-dependent anterograde staining, intracellular recording and immunocytochemistry were used to establish the structure and function of male olfactory receptor neurons (ORNs) and AL projection neurons (PNs). Physiologically characterized neurons were reconstructed using confocal microscopy of α-synapsin stained ALs. The ALs of males and females in both strains had approximately 64 glomeruli. In males the macroglomerular complex (MGC) was morphologically similar in the two strains and consisted of two major compartments, a large, medial compartment folded around a smaller,lateral one. Extensive physiological and morphological analysis revealed that in both strains the major pheromone component-specific ORNs and PNs arborize in the medial MGC glomerulus, whereas those sensitive to the minor pheromone component arborize in the lateral glomerulus. In other words, the two strains have an indistinguishable MGC morphology, but a reversed topology. Apparently,the single-gene-mediated shift that causes a radical change in behavior is located upstream of the antennal lobes, i.e. at the ORN level.
Hydrozoan nematocytes send and receive synaptic signals induced by mechano-chemical stimuli
Authors: Oliver Dominik , Brinkmann Martin , Sieger Thiemo , Thurm Ulrich
Published: August 2008

Nematocytes, the stinging cells of Hydrozoa, can be considered as prototypic mechanosensory hair cells bearing a concentric hair bundle, the cnidocil apparatus. These cells produce typical mechanoreceptor potentials in response to deflection of their cnidocil. Here we show that mechanosensory signals are relayed to neighbouring nematocytes via chemical neurotransmission and that nematocytes receive synaptic input from surrounding nematocytes, hair cells and probably from epithelial cells. Intracellular voltage recordings from stenotele nematocytes of capitate hydroid polyps showed two distinct types of responses when other nematocytes within the same tentacle were mechanically stimulated: (i) graded depolarizations of variable duration (`L-potentials'), and (ii) uniform impulse-like, often repetitive depolarizations (`T-potentials') that occurred in correlation with contractions of epitheliomuscular cells. Voltage clamp experiments showed that despite the stereotyped time course of T-potentials, their generation did not involve electrically excitable conductances. Instead, time course,post-stimulus delay, susceptibility to blockers of neurotransmission and gap junctions, and induction by electrical stimulation of other nematocytes indicate that L- and T-potentials are postsynaptic, most likely glutamatergic potentials. Both result from different presynaptic pathways: L-potentials are induced monosynaptically by presynaptic receptor potentials, T-potentials are most likely triggered by presynaptic action potentials propagating through the ectodermal epithelium via gap junctions. Moreover,contact-chemosensory (phospholipid) stimulation of the presynaptic nematocyte is a positive modulator of the nematocyte's afferent synaptic efficacy and of cnidocyst discharge, both triggered by mechanoreceptor potentials. The results reveal that hydrozoan nematocytes act as bimodal sensory cells, signalling coincident chemical and mechanical stimuli indicative of prey, and receive signals from other nematocytes and sensory cells.
Multifocal optical systems and pupil dynamics in birds
Authors: Lind Olle E. , Kelber Almut , Kröger Ronald H. H.
Published: August 2008

In animal eyes of the camera type longitudinal chromatic aberration causes defocus that is particularly severe in species with short depth of focus. In a variety of vertebrates, multifocal optical systems compensate for longitudinal chromatic aberration by concentric zones of different refractive powers. Since a constricting circular pupil blocks peripheral zones, eyes with multifocal optical systems often have slit pupils that allow light to pass through all zones, irrespective of the state of pupil constriction. Birds have circular pupils and were therefore assumed to have monofocal optical systems. We examined the eyes of 45 species (12 orders) of bird using videorefractometry,and the results are surprising: 29 species (10 orders) have multifocal systems, and only five species (five orders) have monofocal systems. The results from 11 species (four orders) are inconclusive. We propose that pupils`switching' between being fully opened (multifocal principle) to maximally closed (pinhole principle) can make multifocal optical systems useful for animals with circular pupils. Previous results indicate that mice have both multifocal optical systems and switching pupils. Our results suggest that parrots may use a similar mechanism. By contrast, owl pupils responded weakly to changes in illumination and stayed remarkably wide even in full daylight. Moreover, the parrots opened their pupils at higher light levels than owls,which correlates with the differences in sensitivity between diurnal and nocturnal eyes.
Methyl farnesoate couples environmental changes to testicular development in the crabCarcinus maenas
Authors: Nagaraju G. P. C. , Borst D. W.
Published: August 2008

Carcinus maenas males have two major color phases. Green-phase males molt frequently and tend to live in brackish estuaries during the summer. After becoming red-phase males, they molt infrequently, have higher mating success, and live in cooler, deeper water. We found profound differences between these two phases in the way salinity and temperature affect hemolymph levels of methyl farnesoate (MF), a hormone that affects crustacean reproduction. Few green-phase males (<10%) had detectable MF in 33 ppt seawater (SW) at 11 or 18°C. By contrast, about 30% of the red-phase males had detectable MF at either temperature. After transfer to 5 ppt SW, none of the green-phase males had detectable MF at 11°C whereas 100% of green-phase males did at 18°C. By contrast, 100% of the red-phase males had detectable MF in 5 ppt SW at either temperature. At 11°C,green-phase males had detectable MF after eyestalk ablation (ESA), showing that they can produce MF. There was no additional increase in MF levels when ESA animals of either color phase were transferred to 5 ppt SW, suggesting that the eyestalk is the primary regulator of the MF response to low salinity. MF levels of green-phase males were increased by injecting MF, by ESA, or by exposure to 5 ppt SW at 18°C. The testicular index of these treated animals nearly doubled after two weeks. Our results strongly suggest that environmental conditions such as temperature and salinity, affect testicular development in this crab by changing its MF levels.
Allometry of evaporative water loss in marsupials: implications of the effect of ambient relative humidity on the physiology of brushtail possums(Trichosurus vulpecula)
Authors: Cooper C. E. , Withers P. C.
Published: August 2008

To better understand the effects of ambient relative humidity (RH) on physiological variables and the implications of RH-correcting evaporative water loss (EWL) data for marsupials, we examined the effect of RH on EWL,body temperature (Tb), metabolic rate (MR) and thermal conductance (C) of the brushtail possum (Trichosurus vulpecula), a medium-sized marsupial. Correcting EWL data for 27 species of marsupial for water vapour pressure deficit (ΔWVP) in the chamber during measurement significantly increased, rather than decreased, the variability of the allometric relationship for EWL. For the brushtail possum,both ambient temperature (Ta) and RH significantly affected EWL. At Ta=25°C, EWL was independent of RH at≤63% RH, but decreased linearly at higher RH values. At Ta=30°C, EWL was significantly related to RH from 26%to 92% RH. There was a significant effect of Ta on Tb and dry thermal conductance (Cdry;higher at 30°C), but no effect of RH. For MR and wet thermal conductance(Cwet) there was a significant effect of Ta (MR higher and Cwet lower at 25°C), and RH at Ta=30°C (MR higher and Cwet lower at the lowest RH) but not at 25°C. Our results indicate that brushtail possums do not necessarily show the linear relationship between ambient RH and EWL expected for an endotherm, possibly because of behavioural modification of their immediate microclimate. This may account for the failure of WVP deficit correction to improve the allometric EWL relationship for marsupials. Chamber RH is an important environmental factor to be considered when measuring standard physiological variables such as MR and Cwet.