bluuebunny/crossref_metadata_2025 huggingface dataset:
Household catastrophic health expenditure: evidence from Georgia and its policy implications
Authors: Gotsadze George , Zoidze Akaki , Rukhadze Natia
Published: June 2009

Background

To quantify extent of catastrophic household health expenditures, determine factors influencing it and estimate Fairness in Financial Contribution (FFC) index in Georgia to establish the baseline for expected reforms and contribute to the design and fine-tuning of the major reforms in health care financing initiated by the government mid-2007.

Methods

The research is based on the nationally representative Health Care Utilization and Expenditure survey conducted during May-June 2007, prior to preparing for new phase of implementation for the health care financing reforms. Households' catastrophic health expenditures were estimated according to the methodology proposed by WHO – Ke Xu [1]. A logistic regression (logit) model was used to predict probability of catastrophic health expenditure occurrence.

Results

In Georgia between 2000 and 2007 access to care for poor has improved slightly and the share of households facing catastrophic health expenditures have seemingly increased from 2.8% in 1999 to 11.7% in 2007. However, this variance may be associated with the methodological differences of the respective surveys from which the analysis were derived. The high level of the catastrophic health expenditure may be associated with the low share of prepayment in national health expenditure, adequate availability of services and a high level of poverty in the country. Major factors determining the financial catastrophe related to ill health were hospitalization, household members with chronic illness and poverty status of the household. The FFC for Georgia appears to have improved since 2004.

Conclusion

Reducing the prevalence of catastrophic health expenditure is a policy objective of the government, which can be achieved by focusing on increased financial protection offered to poor and expanding government financed benefits for poor and chronically ill by including and expanding inpatient coverage and adding drug benefits. This policy recommendation may also be relevant for other Low and Middle Income countries with similar levels of out of pocket payments and catastrophic health expenditures.
Molecular cloning and expression of a novel trehalose synthase gene from Enterobacter hormaechei
Authors: Yue Ming , Wu Xiu Li , Gong Wei Na , Ding Hong Biao
Published: June 2009

Background

Trehalose synthase (TreS) which converts maltose to trehalose is considered to be a potential biocatalyst for trehalose production. This enzymatic process has the advantage of simple reaction and employs an inexpensive substrate. Therefore, new TreS producing bacteria with suitable enzyme properties are expected to be isolated from extreme environment.

Results

Six TreS producing strains were isolated from a specimen obtained from soil of the Tibetan Plateau using degenerate PCR. A novel treS gene from Enterobacter hormaechei was amplified using thermal asymmetric interlaced PCR. The gene contained a 1626 bp open reading frame encoding 541 amino acids. The gene was expressed in Escherichia coli, and the recombinant TreS was purified and characterized. The purified TreS had a molecular mass of 65 kDa and an activity of 18.5 U/mg. The optimum temperature and pH for the converting reaction were 37°C and 6, respectively. Hg2+, Zn2+, Cu2+and SDS inhibited the enzyme activity at different levels whereas Mn2+ showed an enhancing effect by 10%.

Conclusion

In this study, several TreS producing strains were screened from a source of soil bacteria. The characterization of the recombinant TreS of Enterobacter hormaechei suggested its potential application. Consequently, a strategy for isolation of TreS producing strains and cloning of novel treS genes from natural sources was demonstrated.
Evaluation of the SD FK70 Malaria Ag Plasmodium vivax rapid diagnostic test in a non-endemic setting
Authors: Gillet Philippe , Bosselaers Katrien , Cnops Lieselotte , Bottieau Emmanuel , Van Esbroeck Marjan , Jacobs Jan
Published: June 2009

Background

For clinical and epidemiological reasons, it is interesting to diagnose non-falciparum malaria to the species level. This retrospective study assessed the performance of the SD BIOLINE Malaria Antigen Pv test (FK70), a two-band immunochromatographic test detecting Plasmodium vivax-specific lactate dehydrogenase, on samples of international travellers in a non-endemic setting.

Methods

Stored blood samples from international travellers suspected of malaria were used, with microscopy corrected by PCR as the reference method. Samples infected by Plasmodium vivax (n = 100), Plasmodium falciparum (n = 75), Plasmodium ovale (n = 75) and Plasmodium malariae (n = 25) were included, as well as 100 malaria-negative samples. End points were sensitivity, specificity, inter-reader reliability and reproducibility.

Results

The overall sensitivity of the FK70 for the diagnosis of P. vivax was 88.0% (95% confidence interval (CI): 83.6% – 90.3%). For parasite densities > 500/μl, a sensitivity of 97.2% (CI: 92.6% – 99.1%) was obtained. Specificity was 98.5%, with 4 out of 75 P. falciparum samples testing positive. None of the P. ovale samples tested positive. Nearly two-thirds (57/88, 64.7%) of positive P. vivax samples showed faint or weak line intensities, with stronger line intensities at higher parasite densities. The test showed excellent reproducibility and reliability for test results and line intensities (kappa values exceeding 0.98 and 0.87 respectively).

Conclusion

The FK70 test performed well in diagnosing P. vivax infections in a non-endemic reference setting. It can be of added value to microscopy in species differentiation of malaria infections, especially at parasite densities > 500/μl.
Spatial and temporal distribution of falciparum malaria in China
Authors: Lin Hualiang , Lu Liang , Tian Linwei , Zhou Shuisen , Wu Haixia , Bi Yan , Ho Suzanne C , Liu Qiyong
Published: June 2009

Background

Falciparum malaria is the most deadly among the four main types of human malaria. Although great success has been achieved since the launch of the National Malaria Control Programme in 1955, malaria remains a serious public health problem in China. This paper aimed to analyse the geographic distribution, demographic patterns and time trends of falciparum malaria in China.

Methods

The annual numbers of falciparum malaria cases during 1992–2003 and the individual case reports of each clinical falciparum malaria during 2004–2005 were extracted from communicable disease information systems in China Center for Diseases Control and Prevention. The annual number of cases and the annual incidence were mapped by matching them to corresponding province- and county-level administrative units in a geographic information system. The distribution of falciparum malaria by age, gender and origin of infection was analysed. Time-series analysis was conducted to investigate the relationship between the falciparum malaria in the endemic provinces and the imported falciparum malaria in non-endemic provinces.

Results

Falciparum malaria was endemic in two provinces of China during 2004–05. Imported malaria was reported in 26 non-endemic provinces. Annual incidence of falciparum malaria was mapped at county level in the two endemic provinces of China: Yunnan and Hainan. The sex ratio (male vs. female) for the number of cases in Yunnan was 1.6 in the children of 0–15 years and it reached 5.7 in the adults over 15 years of age. The number of malaria cases in Yunnan was positively correlated with the imported malaria of concurrent months in the non-endemic provinces.

Conclusion

The endemic area of falciparum malaria in China has remained restricted to two provinces, Yunnan and Hainan. Stable transmission occurs in the bordering region of Yunnan and the hilly-forested south of Hainan. The age and gender distribution in the endemic area is characterized by the predominance of adult men cases. Imported falciparum malaria in the non-endemic area of China, affected mainly by the malaria transmission in Yunnan, has increased both spatially and temporally. Specific intervention measures targeted at the mobile population groups are warranted.
Cadmium induces lung inflammation independent of lung cell proliferation: a molecular approach
Authors: Kundu Subhadip , Sengupta Suman , Chatterjee Soumya , Mitra Soham , Bhattacharyya Arindam
Published: June 2009

Background

Cadmium is one of the inflammation-related xenobiotics and has been regarded as a potent carcinogen. The relationship between inflammation and cell proliferation due to chronic infection has been studied, but the mechanism is not fully clear. Though the mode of cadmium toxicity is well characterized in animal cells, still it requires some further investigations. Previously we reported that cadmium induces immune cell death in Swiss albino mice. In the present study we showed that instead of inducing cell death mechanism, cadmium in low concentration triggers proliferation in mice lung cell and our results reveals that prior to the induction of proliferation it causes severe inflammation.

Methods

Swiss albino mice were treated with different concentrations of cadmium to determine the LD50. Mice were subdivided (5 mice each) according to the exposure period (15, 30, 45, 60 days) and were given sub lethal dose (5 mg/Kg body weight) of cadmium chloride and ibuprofen (50 mg/Kg body weight, recommended dose) once in a week. SEM and histology were performed as evidence of changes in cellular morphology. Inflammation was measured by the expression of Cox-2 and MMPs. Expression of proinflammatory cytokines (Cox-2, IL-6), signaling and cell cycle regulatory molecules (STAT3, Akt, CyclinD1) were measured by western blot, ELISA and immunoprecipitation. Mutagenecity was evidenced by comet assay. Cell proliferation was determined by cell count, cell cycle and DNA analysis.

Results

Prolonged exposure of low concentration of cadmium resulted in up regulation of proinflammatory cytokines and cell cycle regulatory molecules. Though NSAIDs like Ibuprofen reduces the expression of inflammatory cytokines, but it did not show any inhibitory effect on cadmium adopted lung cell proliferation.

Conclusion

Our results prove that cadmium causes both inflammation and cell proliferation when applied in a low dose but proliferative changes occur independent of inflammation.
An In Vivo Mouse Model of Long-Term Potentiation at Synapses between Primary Afferent C-Fibers and Spinal Dorsal Horn Neurons: Essential Role of Ephb1 Receptor
Authors: Liu Wen-Tao , Han Yuan , Li Hao-Chuan , Adams Brandt , Zheng Ji-Hong , Wu Yong-Ping , Henkemeyer Mark , Song Xue-Jun
Published: June 2009

Background

Long-term potentiation (LTP), a much studied cellular model of synaptic plasticity, has not been demonstrated at synapses between primary afferent C-fibers and spinal dorsal horn (DH) neurons in mice in vivo. EphrinB-EphB receptor signaling plays important roles in synaptic connection and plasticity in the nervous system, but its role in spinal synaptic plasticity remains unclear.

Results

This study characterizes properties of LTP at synapses of C-fibers onto neurons in the superficial DH following high-frequency stimulation (HFS) of a peripheral nerve at an intensity that activates C-fibers and examines associated activation of Ca2+/calmodulin-activated protein kinase II (p-CaMKII), extracellular signal-regulated kinase (p-ERK) and the cyclic AMP response element binding protein (p-CREB) and expression of c-Fos, and it investigates further roles for the EphB1 receptor in LTP. HFS induced LTP within 5 min and lasts for 3–8 h during the period of recording and resulted in upregulation of p-CaMKII, p-ERK and p-CREB protein levels in the spinal cord and expression of c-Fos in DH. Intrathecal pretreatment of MK-801 or EphB2-Fc prevented LTP and significantly reduced upregulation of p-CaMKII, p-ERK, p-CREB and c-Fos. Further, targeted mutation of EphB1 receptor prevented induction of LTP and associated increases in phosphorylation of CaMKII, ERK, and CREB.

Conclusion

This study provides an in vivo mouse model of LTP at synapses of C-fibers onto the superficial DH neurons that will be valuable for studying the DH neuron excitability and their synaptic plasticity and hyperalgesia. It further takes advantage of examining functional implications of a specific gene targeted mice and demonstrates that the EphB1 receptor is essential for development of LTP.
Occurrence and adverse effect on outcome of hyperlactatemia in the critically ill
Authors: Khosravani Houman , Shahpori Reza , Stelfox H Thomas , Kirkpatrick Andrew W , Laupland Kevin B
Published: June 2009

Introduction

Hyperlactatemia is frequent in critically ill patients and is often used as a marker of adverse outcome. However, studies to date have focused on selected intensive care unit (ICU) populations. We sought to determine the occurrence and relation of hyperlactatemia with ICU mortality in all patients admitted to four ICUs in a large regional critical care system.

Methods

All adults ([greater than or equal to] 18 years) admitted to ICUs in the Calgary Health Region (population 1.2 million) during 2003 to 2006 were included retrospectively. Lactate determinations were at the discretion of the attending service and hyperlactatemia was defined by a lactate level > 2 mmol/L.

Results

A total of 13,932 ICU admissions occurred among 11,581 patients. The median age was 63 years (37% female), the mean APACHE II score was 25 ± 9 (n = 13,922). At presentation (within first day of admission), 12,246 patients had at least one lactate determination and the median peak lactate was 1.8 (IQR 1.2 to 2.9) mmol/L. The cumulative incidence of at least one documented episode of hyperlactatemia was 5578/13,932 (40%); 5058 (36%) patients had hyperlactatemia at presentation, and a further 520 (4%) developed hyperlactatemia subsequently. The incidence of hyperlactatemia varied significantly by major admitting diagnostic category (P < 0.001) and was highest among neuro/trauma patients 1053/2328 (45%), followed by medical 2047/4935 (41%), other surgical 900/2274 (40%), and cardiac surgical 1578/4395 (36%). Among a cohort of 9107 first admissions with ICU stay of at least one day, both hyperlactatemia at presentation (712/3634 (20%) vs. 289/5473 (5%); P < 0.001) and its later development (101/379 (27%) vs. 188/5094 (4%); P < 0.001) were associated with significantly increased case fatality rates as compared with patients without elevated lactate. After controlling for confounding effects in multivariable logistic regression analysis, hyperlactatemia was an independent risk factor for death.

Conclusions

Hyperlactatemia is common among the critically ill and predicts risk for death.
Timing of the Ovarian Circadian Clock Is Regulated by Gonadotropins
Authors: Yoshikawa Tomoko , Sellix Michael , Pezuk Pinar , Menaker Michael
Published: June 2009

The timing of ovulation is critically important to the success of reproduction. Current thinking attributes the timing of ovulation to LH secretion by the pituitary, itself timed by signals from the hypothalamus. The discovery of an internal circadian timer in the ovary raises the possibility that ovulation is in fact timed by an interaction between clocks in the hypothalamus/pituitary and those in the ovary. We asked whether ovarian clocks were influenced by signals from the brain and pituitary. Ovaries of Period1-luciferase transgenic rats display circadian rhythms in vitro. To determine whether the phase of these rhythms is set by neural or endocrine signals, we surgically denervated or heterotopically transplanted ovaries with or without encapsulation in dialysis membranes. Animals’ light-dark cycles were phase advanced or delayed 6 h, and the resetting of the ovarian clock was tracked by culturing ovaries at intervals over the next 12 d. Resetting trajectories of control, surgically denervated, and encapsulated ovaries were similar, demonstrating that endocrine signals are sufficient to transmit phase information to the ovary. We next evaluated LH and FSH as potential endocrine signals. Using the phase of Per1-luc expression in granulosa cell cultures, we demonstrated that both of these pituitary hormones caused large phase shifts when applied to the cultured cells. We hypothesize that the ovarian circadian clock is entrained by hormonal signals from the pituitary and that ovulation depends, in part, on the phase in the ovarian circadian cycle at which these signals occur.
The Uterine Placental Bed Renin-Angiotensin System in Normal and Preeclamptic Pregnancy
Authors: Anton Lauren , Merrill David C. , Neves Liomar A. A. , Diz Debra I. , Corthorn Jenny , Valdes Gloria , Stovall Kathryn , Gallagher Patricia E. , Moorefield Cheryl , Gruver Courtney , Brosnihan K. Bridget
Published: June 2009

Previously, we demonstrated activation of the renin-angiotensin system in the fetal placental chorionic villi, but it is unknown whether the immediately adjacent area of the maternal uterine placental bed is regulated similarly. This study measured angiotensin peptides, renin-angiotensin system component mRNAs, and receptor binding in the fundus from nonpregnant subjects (n = 19) and in the uterine placental bed from normal (n = 20) and preeclamptic (n = 14) subjects. In the uterine placental bed from normal pregnant women, angiotensin II peptide levels and angiotensinogen, angiotensin-converting enzyme, angiotensin receptor type 1 (AT1), AT2, and Mas mRNA expression were lower as compared with the nonpregnant subjects. In preeclamptic uterine placental bed, angiotensin II peptide levels and renin and angiotensin-converting enzyme mRNA expression were significantly higher than normal pregnant subjects. The AT2 receptor was the predominant receptor subtype in the nonpregnant fundus, whereas all angiotensin receptor binding was undetectable in normal and preeclamptic pregnant uterine placental bed compared with nonpregnant fundus. These findings suggest that the maternal uterine placental bed may play an endocrine role by producing angiotensin II, which acts in the adjacent placenta to vasoconstrict fetal chorionic villi vessels where we have shown previously that AT1 receptors predominate. This would lead to decreased maternal-fetal oxygen exchange and fetal nutrition, a known characteristic of preeclampsia.
Soluble Corticotropin-Releasing Hormone Receptor 2α Splice Variant Is Efficiently Translated But Not Trafficked for Secretion
Authors: Evans Ryan T. , Seasholtz Audrey F.
Published: June 2009

CRH directs the physiological and behavioral responses to stress. Its activity is mediated by CRH receptors (CRH-R) 1 and 2 and modulated by the CRH-binding protein. Aberrant regulation of this system has been associated with anxiety disorders and major depression, demonstrating the importance of understanding the regulation of CRH activity. An mRNA splice variant of CRH-R2α (sCRH-R2α) was recently identified that encodes the receptor’s ligand-binding extracellular domain but terminates before the transmembrane domains. It was therefore predicted to serve as a secreted decoy receptor, mimicking the ability of CRH-binding protein to sequester free CRH. Although the splice variant contains a premature termination codon, predicting its degradation by nonsense-mediated RNA decay, cycloheximide experiments and polysome profiles demonstrated that sCRH-R2α mRNA escaped this regulation and was efficiently translated. However, the resulting protein was unable to serve as a decoy receptor because it failed to traffic for secretion because of an ineffective signal peptide and was ultimately subjected to proteosomal degradation. Several other truncated splice variants of G protein-coupled transmembrane receptors regulate the amount of full-length receptor expression through dimerization and misrouting; however, receptor binding assays and immunofluorescence of cells cotransfected with sCRH-R2α and CRH-R2α or CRH-R1 indicated that sCRH-R2α protein does not alter trafficking or binding of full-length CRH-R. Although sCRH-R2α protein does not appear to function as an intracellular or extracellular decoy receptor, the regulated unproductive splicing of CRH-R2α pre-mRNA to sCRH-R2α may selectively alter the cellular levels of full-length CRH-R2α mRNA and hence functional CRH-R2α receptor levels.
24-Dehydrocholesterol Reductase/Seladin-1: A Key Protein Differentially Involved in Adrenocorticotropin Effects Observed in Human and Rat Adrenal Cortex
Authors: Battista Marie-Claude , Roberge Claude , Martinez Antoine , Gallo-Payet Nicole
Published: June 2009

DHCR24 (24-dehydrocholesterol reductase), or seladin-1, is one of the most expressed genes in the adrenal gland. Because the rat and human adult adrenal cortex differ in their respective functional properties, the aim of the present study was to verify whether seladin-1 may be differentially involved in basal and ACTH-stimulated steroidogenesis and oxidative stress management. Seladin-1 expression was predominantly observed in both human and rat zona fasciculata, with a predominant cytoplasmic localization in human cells and a nucleo-cytoplasmic distribution in rat cells. In human fasciculata cells, localization of the protein was primarily associated with the endoplasmic reticulum. Although its expression was increased by ACTH, its intracellular localization was not altered by ACTH treatment (10 nm) or by the seladin-1 inhibitor U18666A (75 nm). Preincubation with U18666A did not modify the ACTH-induced increase in cortisol secretion but abolished the ACTH-induced increase in dehydroepiandrosterone secretion. In rat fasciculata cells, ACTH induced a massive redistribution of seladin-1 from the cytoplasm (cis-Golgi apparatus) to the nucleus, which was inhibited by preincubation with U18666A. Preincubation with U18666A also decreased ACTH-induced seladin-1 and 11β-hydroxylase protein expression as well as corticosterone production, increased ACTH-induced ROS production but decreased ACTH-induced expression of the detoxifying protein aldo-ketoreductase 1b7. Thus, protection against acutely elevated ACTH-induced oxidative stress in rat fasciculata cells is correlated with nuclear relocalization of seladin-1 and its effects on cellular detoxifying machinery. Altogether, these results indicate that seladin-1 expression and intracellular localization are correlated with both the intensity and nature of ACTH-induced steroidogenesis and resultant oxidative stress.
Rosiglitazone Increases the Expression of Peroxisome Proliferator-Activated Receptor-γ Target Genes in Adipose Tissue, Liver, and Skeletal Muscle in the Sheep Fetus in Late Gestation
Authors: Muhlhausler B. S. , Morrison J. L. , McMillen I. C.
Published: June 2009

Exposure to maternal overnutrition increases the expression of peroxisome proliferator-activated receptor-γ (PPARγ) in adipose tissue before birth, and it has been proposed that the precocial activation of PPARγ target genes may lead to increased fat deposition in postnatal life. In this study, we determined the effect of intrafetal administration of a PPARγ agonist, rosiglitazone, on PPARγ target gene expression in fetal adipose tissue as well indirect actions of rosiglitazone on fetal liver and skeletal muscle. Osmotic pumps containing rosiglitazone (n = 7) or vehicle (15% ethanol, n = 7) were implanted into fetuses at 123–126 d gestation (term = 150 ± 3 d gestation). At 137–141 d gestation, tissues were collected and mRNA expression of PPARγ, lipoprotein lipase (LPL), adiponectin, and glycerol-3-phosphate dehydrogenase (G3PDH) in adipose tissue, PPARα and PPARγ-coactivator 1α (PGC1α) in liver and muscle and phosphoenolpyruvate carboxykinase (PEPCK) in liver determined by quantitative real-time RT-PCR. Plasma insulin concentrations were lower in rosiglitazone-treated fetuses (P < 0.02). Rosiglitazone treatment resulted in increased expression of LPL and adiponectin mRNA (P < 0.01) in fetal adipose tissue. The expression of PPARα mRNA in liver (P < 0.05) and PGC1α mRNA (P < 0.02) in skeletal muscle were also increased by rosiglitazone treatment. Rosiglitazone treatment increased expression of PPARγ target genes within fetal adipose tissue and also had direct or indirect actions on the fetal liver and muscle. The effects of activating PPARγ in fetal adipose tissue mimic those induced by prenatal overnutrition, and it is therefore possible that activation of PPARγ may be the initiating mechanism in the pathway from prenatal overnutrition to postnatal obesity.
Smelling the difference: controversial ideas in insect olfaction
Authors: Pellegrino Maurizio , Nakagawa Takao
Published: June 2009

In animals, the sense of smell is often used as a powerful way to attract potential mates, to find food and to explore the environment. Different animals evolved different systems to detect volatile odorants, tuned to the specific needs of each species. Vertebrates and nematodes have been used extensively as models to study the mechanisms of olfaction: the molecular players are olfactory receptors (ORs) expressed in olfactory sensory neurons(OSNs) where they bind to volatile chemicals, acting as the first relay of olfactory processing. These receptors belong to the G protein-coupled receptor(GPCR) superfamily; binding to odorants induces the production and amplification of second messengers, which lead to the depolarization of the neuron. The anatomical features of the insect olfactory circuit are similar to those of mammals, and until recently it was thought that this similarity extended to the ORs, which were originally annotated as GPCRs. Surprisingly,recent evidence shows that insect ORs can act like ligand-gated ion channels,either completely or partially bypassing the amplification steps connected to the activation of G proteins. Although the involvement of G proteins in insect olfactory signal transduction is still under question, this new discovery raises fascinating new questions regarding the function of the sense of smell in insects, its evolution and potential benefits compared with its mammalian counterpart.
Effects of corticosterone on innate and humoral immune functions and oxidative stress in barn owl nestlings
Authors: Stier Kim Silvana , Almasi Bettina , Gasparini Julien , Piault Romain , Roulin Alexandre , Jenni Lukas
Published: June 2009

The costs of coping with stressful situations are traded-off against other functions such as immune responses. This trade-off may explain why corticosterone secretion reduces immune reactions. Corticosterone differentially affects various immunity components. However, which component is suppressed varies between studies. It remains unclear whether the trade-off in energy, nutrition, autoimmunity or oxidative stress accounts for differential immunosuppression. In this study, we investigated whether corticosterone differentially affects the constitutive innate and humoral acquired immunity. We used barn owl nestlings, implanting 50% with a corticosterone-releasing pellet and the other 50% with a placebo pellet. To measure the effect on humoral immunity we vaccinated 50% of the corticosterone-nestlings and 50% of the placebo-nestlings with the antigens`Tetravac' and the other 50% were injected with PBS. To assess the costs of elevated corticosterone, we measured body mass and resistance to oxidative stress. Administration of corticosterone increased corticosterone levels whereas vaccination induced the production of antibodies. Corticosterone reduced the production of antibodies, but it did not significantly affect the constitutive innate immunity. Corticosterone reduced body growth and resistance to oxidative stress. Under stressful conditions barn owl nestlings seem to keep the constitutive innate immunity, whereas elevated corticosterone levels negatively affected inducible immune responses. We found evidence that mounting a humoral immune reaction is not costly in terms of growth, but reduces the resistance to oxidative stress independently of corticosterone administration. We suggest that humoral immunity is suppressed because the risk of immunopathologies may be disproportionately high when mounting an antibody response under stressful situations.
Temperature-induced elevation of basal metabolic rate does not affect testis growth in great tits
Authors: Caro Samuel P. , Visser Marcel E.
Published: June 2009

The timing of reproduction varies from year to year in many bird species. To adjust their timing to the prevailing conditions of that year, birds use cues from their environment. However, the relative importance of these cues,such as the initial predictive (e.g. photoperiod) and the supplemental factors(e.g. temperature), on the seasonal sexual development are difficult to distinguish. In particular, the fine-tuning effect of temperature on gonadal growth is not well known. One way temperature may affect timing is via its strong effect on energy expenditure as gonadal growth is an energy-demanding process. To study the interaction of photoperiod and temperature on gonadal development, we first exposed 35 individually housed male great tits (Parus major) to mid-long days (after 6 weeks of 8 h L:16 h D at 15°C, photoperiod was set to 13 h L:11 h D at 15°C). Two weeks later, for half of the males the temperature was set to 8°C, and for the other half to 22°C. Unilateral laparotomies were performed at weeks 5(i.e one week before the birds were transferred to mid-long days), 8 and 11 to measure testis size. Two measures of basal metabolic rate (BMR) were performed at the end of the experiment (weeks 11 and 12). Testis size increased significantly during the course of the experiment, but independently of the temperature treatment. BMR was significantly higher in birds exposed to the cold treatment. These results show that temperature-related elevation of BMR did not impair the long-day-induced testis growth in great tits. As a consequence, temperature may not be a crucial cue and/or constraint factor in the fine-tuning of the gonadal recrudescence in male great tits, and testis growth is not a high energy-demanding seasonal process.
Molecular identification of candidate chemoreceptor genes and signal transduction components in the sensory epithelium ofAplysia
Authors: Cummins S. F. , Leblanc L. , Degnan B. M. , Nagle G. T.
Published: June 2009

An ability to sense and respond to environmental cues is essential to the survival of most marine animals. How water-borne chemical cues are detected at the molecular level and processed by molluscs is currently unknown. In this study, we cloned two genes from the marine mollusk Aplysia dactylomela which encode multi-transmembrane proteins. We have performed in situ hybridization that reveals expression and spatial distribution within the long-distance chemosensory organs, the rhinophores. This finding suggests that they could be receptors involved in binding water-borne chemicals and coupling to an intracellular signal pathway. In support of this, we found expression of a phospholipase C and an inositol trisphosphate receptor in the rhinophore sensory epithelia and possibly distributed within outer dendrites of olfactory sensory neurons. In Aplysia, mate attraction and subsequent reproduction is initiated by responding to a cocktail of water-borne protein pheromones released by animal conspecifics. We show that the rhinophore contraction in response to pheromone stimulants is significantly altered following phospholipase C inhibition. Overall, these data provide insight into the molecular components of chemosensory detection in a mollusk. An important next step will be the elucidation of how these coordinate the detection of chemical cues present in the marine environment and activation of sensory neurons.
Agonistic behavior enhances adult neurogenesis in maleAcheta domesticuscrickets
Authors: Ghosal Kaushik , Gupta Mohit , Killian Kathleen A.
Published: June 2009

We examined the effect of agonistic behavior on cell proliferation and neurogenesis in the central nervous system (CNS) of adult male Acheta domesticus crickets. We combined 5-bromo,2′deoxyuridine(BrdU)-labeling of dividing cells with immunocytochemical detection of the neuronal marker horseradish peroxidase to examine the proliferation of progenitor cells and the survival of newborn neurons. In crickets, the mushroom bodies of the brain contain clusters of proliferative cells that divide and generate new neurons in adulthood. Pairs of male crickets were allowed to fight and establish social rank and were then injected with BrdU. Proliferation of mushroom body neurogenic cluster cells was unaffected by agonistic interactions; 24 h after a fight, the number of BrdU positive cells in fought and un-fought males did not significantly differ. However, agonistic interactions did influence cell survival. Two weeks after an agonistic interaction, fought males had more newborn neurons than males that did not fight. There was also a rank-specific effect because dominant males had significantly more new neurons than subordinates. We also report for the first time that neurogenesis in adult crickets can occur in other regions of the brain and in other CNS ganglia, including the terminal abdominal ganglion(TAG). Agonistic interactions enhanced the proliferation of these distributed precursor cells but did not increase the survival of the newborn neurons generated by these cells.
Enriching early adult environment affects the copulation behaviour of a tephritid fly
Authors: Díaz-Fleischer Francisco , Arredondo José , Aluja Martín
Published: June 2009

Early adult experiences in enriched environments favours animal brain and behavioural development ultimately resulting in an increased fitness. However,measuring the effect of environmental enrichment in animal behaviour in nature is often a complicated task, considering the complexity of the natural environment. We expanded previous studies to evaluate how early experience in an enriched environment affects copulation behaviour when animals are confronted with a complex semi-natural environment. Anastrepha ludensflies are an ideal model system for studying these effects because their natural habitats differ significantly from the cage environments in which these flies are reared for biological control purposes. For example, in the field, males form leks of up to six individuals. Each male defends a territory represented by a tree leaf whereas in rearing cages, territories are completely reduced because of the high population density. In a series of three experiments, we observed that male density represented the most influential stimulus for A. ludens male copulation success. Males that experienced lower densities in early adulthood obtained the highest proportion of copulations. By contrast, female copulation behaviour was not altered by female density. However, exposure to natural or artificial leaves in cages in which flies were kept until tested influenced female copulation behaviour. Females that were exposed to enriched environments exhibited a shorter latency to mate and shorter copulation durations with males than females reared in poor environments. We discuss the influence of early experience on male copulation success and female-mating choosiness.
Embryonic diapause highlighted by differential expression of mRNAs for ecdysteroidogenesis, transcription and lipid sparing in the cricketAllonemobius socius
Authors: Reynolds Julie A. , Hand Steven C.
Published: June 2009

Embryos of the ground cricket, Allonemobius socius, enter diapause 4–5 days post-oviposition and overwinter in this dormant state that is characterized by developmental arrest. Suppressive subtractive hybridization and quantitative real-time PCR reveal eight candidate genes in pre-diapause embryos that show promise as regulators of diapause entry, when compared with embryos not destined for diapause. Identifications are based both on the magnitude/consistency of differential mRNA abundances and the predicted functions of their products when placed in context of the physiological and biochemical events of diapause characterized in our companion paper. The proteins CYP450, AKR and RACK1 (associated with ecdysteroid synthesis and signaling) are consistently upregulated in pre-diapause, followed by major downregulation later in diapause. The pattern suggests that elevated ecdysone may facilitate onset of diapause in A. socius. Upregulation seen for the transcription factors Reptin and TFDp2 may serve to depress transcription and cell cycle progression. Cathpesin B-like protease, ACLY and MSP are three downregulated genes associated with yolk mobilization and/or metabolism that we predict may promote lipid sparing. Finally, embryos that have been in diapause for 10 days show a substantially different pattern of mRNA expression compared with either pre-diapause or embryos not destined for diapause, with the majority of mRNAs examined being downregulated. These transcript levels in later diapause suggest that a number of upregulated genes in pre-diapause are transiently expressed and are less essential as diapause progresses.
Zebra mussels anchor byssal threads faster and tighter than quagga mussels in flow
Authors: Peyer Suzanne M. , McCarthy Alice J. , Lee Carol Eunmi
Published: June 2009

While the invasive zebra mussel Dreissena polymorpha has rapidly spread throughout the Great Lakes and inland waterways, it is being displaced by the quagga mussel Dreissena bugensis in shallow water habitats. However, zebra mussels remain dominant in areas with higher water velocity. We hypothesized that the persistence of zebra over quagga mussels in habitats with higher water velocity might result from greater rate and strength of byssal thread attachment. We examined whether zebra mussels relative to quagga mussels have: (1) higher byssal thread synthesis rate, (2) lower dislodgment in flow and (3) greater mechanical force required for detachment from substrate. Specifically, we examined byssal thread synthesis rate and dislodgment of both species in response to water velocities of 0, 50, 100 and 180 cm s–1. Byssal thread synthesis rate was significantly higher for zebra than for quagga mussels at all velocities. Dislodgment from the substrate increased for both species with increasing velocity but was significantly lower for zebra than for quagga mussels. We also tested the mechanical force to detach mussels after short (32 h) and long (two and three months) periods of attachment on hard substrate. Detachment force was significantly higher for zebra than for quagga mussels only after short-term attachment. Higher byssal thread synthesis rate in zebra mussels was a likely factor that minimized their dislodgment in flow and increased short-term attachment strength. Differences in byssal thread synthesis rate between the two species might partly account for the ability of zebra mussels to maintain dominance over quagga mussels in habitats with high velocities.
Shape learning and discrimination in reef fish
Authors: Siebeck U. E. , Litherland L. , Wallis G. M.
Published: June 2009

Coral reef fish live in a complex world of colour and patterns. If they are to survive they need to be able to correctly identify the things they see(e.g. predators, prey) and act accordingly (e.g. flee, feed). This paper investigates whether discrimination is limited to ecologically relevant stimuli or is in fact more adaptable. Our work focuses on the reef damselfish Pomacentrus amboinensis. Within a day or two of capture the fish demonstrated an ability to associate an arbitrary stimulus with a food reward and to discriminate the reward stimulus from a distractor matched along various physical dimensions. In our initial experiments the reward was directly associated with the target. In the final experiment, however, the reward was separated from the target in both space and time, thereby eliminating a weakness applicable to the majority of food reward experiments involving fish; namely, the presence of olfactory cues emanating from the feeding tubes. All fish were not only able to solve this task but also showed anticipatory behaviour (also referred to as goal tracking). We conclude that freshly caught reef fish not only are able to quickly learn and discriminate between novel stimuli on the basis of shape but are also able to interpret stimuli as a predictor for the availability of food at a different time and place (anticipatory behaviour).
Four-choice sound localization abilities of two Florida manatees,Trichechus manatus latirostris
Authors: Colbert Debborah E. , Gaspard Joseph C. , Reep Roger , Mann David A. , Bauer Gordon B.
Published: June 2009

The absolute sound localization abilities of two Florida manatees(Trichechus manatus latirostris) were measured using a four-choice discrimination paradigm, with test locations positioned at 45 deg., 90 deg.,270 deg. and 315 deg. angles relative to subjects facing 0 deg. Three broadband signals were tested at four durations (200, 500, 1000, 3000 ms),including a stimulus that spanned a wide range of frequencies (0.2–20 kHz), one stimulus that was restricted to frequencies with wavelengths shorter than their interaural time distances (6–20 kHz) and one that was limited to those with wavelengths longer than their interaural time distances(0.2–2 kHz). Two 3000 ms tonal signals were tested, including a 4 kHz stimulus, which is the midpoint of the 2.5–5.9 kHz fundamental frequency range of manatee vocalizations and a 16 kHz stimulus, which is in the range of manatee best-hearing sensitivity. Percentage correct within the broadband conditions ranged from 79% to 93% for Subject 1 and from 51% to 93% for Subject 2. Both performed above chance with the tonal signals but had much lower accuracy than with broadband signals, with Subject 1 at 44% and 33% and Subject 2 at 49% and 32% at the 4 kHz and 16 kHz conditions, respectively. These results demonstrate that manatees are able to localize frequency bands with wavelengths that are both shorter and longer than their interaural time distances and suggest that they have the ability to localize both manatee vocalizations and recreational boat engine noises.
Rhabdom constriction enhances filtering by the red screening pigment in the eye of the Eastern Pale Clouded yellow butterfly, Colias erate(Pieridae)
Authors: Arikawa Kentaro , Pirih Primoz , Stavenga Doekele G.
Published: June 2009

Here we report the remarkable anatomy of the eye of the Eastern Pale Clouded yellow butterfly, Colias erate. An ommatidium of C. erate bears nine photoreceptors, R1–9, which together form a tiered and fused rhabdom. The distal tier of the rhabdom consists of the rhabdomeral microvilli of R1–4 photoreceptors, R5–8 photoreceptors contribute the proximal tier, and the R9 photoreceptor adds a few microvilli at the base. In transverse sections, four spots of red pigment surrounding the rhabdom are evident in the ventral region of the eye. The red pigment acts as a strong red filter for the proximal photoreceptors. The arrangement of the pigment spots distinguishes the ommatidia into three types: trapezoidal (type I), square(type II) and rectangular (type III). In all types of ommatidia, the distal and the proximal tiers of the rhabdom are divided by a strong constriction,clearly to enhance the filtering effect of the red pigment. The ommatidial heterogeneity can also be observed by optical measurements. The eye shine,resulting from tapetal reflections, peaks in type I ommatidia at 660 nm, and in type II and III ommatidia at 730 nm. The far-red-peaking eye shine indicates that C. erate has far-red-sensitive photoreceptors. Type I ommatidia fluoresce under violet excitation, implying the presence of a violet-absorbing pigment that acts as a short-wavelength filter.
Peripheral and behavioral plasticity of pheromone response and its hormonal control in a long-lived moth
Authors: Lemmen Joelle , Evenden Maya
Published: June 2009

Reproductive success in many animals depends on the efficient production of and response to sexual signals. In insects, plasticity in sexual communication is predicted in species that experience periods of reproductive inactivity when environmental conditions are unsuitable for reproduction. Here, we study a long-lived moth Caloptilia fraxinella (Ely) (Lepidoptera:Gracillariidae) that is reproductively inactive from eclosion in summer until the following spring. Male sex pheromone responsiveness is plastic and corresponds with female receptivity. Pheromone response plasticity has not been studied in a moth with an extended period of reproductive inactivity. In this study, we ask whether male antennal response and flight behavior are plastic during different stages of reproductive inactivity and whether these responses are regulated by juvenile hormone. Antennal response to the pheromone blend is significantly reduced in reproductively inactive males tested in the summer and autumn as compared with reproductively active males tested in the spring. Reproductively inactive autumn but not summer males show lower antennal responses to individual pheromone components compared with spring males. Treatment with methoprene enhances antennal response of autumn but not summer males to high doses of the pheromone blend. Behavioral response is induced by methoprene treatment in males treated in the autumn but not in the summer. Plasticity of pheromone response in C. fraxinella is regulated, at least in part, by the peripheral nervous system. Antennal and behavioral response to pheromone differed in reproductively active and inactive males and increased with methoprene treatment of inactive males.
Configuration of Adsorbed Phases and Their Evolution to Absorbent States in the CH4–O2 Catalytic Reaction
Authors: Cortés Joaquín , Valencia Eliana
Published: June 2009

Through kinetic Monte Carlo simulations of a catalytic reaction with a complex mechanism, such as the catalytic oxidation of methane, it is shown that the temporal evolution of the adsorbed phase to absorbent states is interpreted by an exponential decay of production. This semiempirical law, which has been used previously for systems with simple mechanisms, describes reactive and absorbent states and is in agreement with the results of the phase diagram. Substrates corresponding to square, hexagonal, and eight-coordination lattices are analyzed. In the first case it is shown that for most of the phase diagram the absorbent configuration of the adsorbed phase complies with the checkerboard structure found by Brosilow and Ziff in the case of a simple mechanism for the CO–NO reaction over a square lattice.
Kinetic Study of Singlet-Oxygen Quenching by Caffeic Acid and Related Phenols
Authors: Ohara Keishi , Ichimura Yoko , Nagaoka Shin-ichi
Published: June 2009

The second-order rate constants (kQ) of singlet-oxygen quenching by caffeic acid and related phenols were measured in ethanol and toluene. Caffeic acid derivatives deactivate singlet-oxygen largely by physical quenching at kQ = 106–107 M−1 s−1 through the charge-transfer transition state.
Three-Dimensional Morphological Chirality Induction in Polythiophene Polymer Deposit Using a Magnetic Field
Authors: Tanimoto Yoshifumi , Shinyama Ami , Omote Kanako
Published: June 2009

Effects of a vertical magnetic field on the three-dimensional morphology of a polythiophene deposit formed by anodic oxidation were examined. At 4 T, a left-handedly twisted polymer deposit is obtained, although the shape is uncurved in a zero field. The twist configuration is right-handed when the field direction is reversed. The mechanism of magnetic field effects is discussed.
High-Resolution Solid-State NMR Studies of Natural Abundant 15N Observed in Halogen-Bridged One-Dimensional Complexes, [NiX(chxn)2]X2 and [Pd(chxn)2][PdX2(chxn)2]Y4 (chxn = (1R,2R)-Diaminocyclohexane; Y = X (Halogen), NO3, and ClO4)
Authors: Kimura Noriyoshi , Shimizu Tadashi , Ikeda Ryuichi
Published: June 2009

We performed solid-state NMR measurements of 15N nuclei with a low natural abundance in chxn ligands in halogen-bridged Pd and Ni complexes with a one-dimensional (1-D) structure. Spectra obtained for 15N bonded to Pd2+, Pd4+, and Ni3+ were clearly separated from each other, and it was shown that information on electronic and magnetic structures of 1-D chains was obtained more sensitively than from 13C NMR data. A characteristic new result is a marked broadening of the signal from nitrogen bonded to the Pd4+ in [Pd(chxn)2][PdBr2(chxn)2]Br4, which is expected to be closely connected with polarons formed on 1-D chains.