bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon black and titanium dioxide nanoparticles elicit distinct apoptotic pathways in bronchial epithelial cells
Authors: Hussain Salik , Thomassen Leen CJ , Ferecatu Ioana , Borot Marie-Caroline , Andreau Karine , Martens Johan A , Fleury Jocelyne , Baeza-Squiban Armelle , Marano Francelyne , Boland Sonja 
Published: April 2010

Abstract

Background
Increasing environmental and occupational exposures to nanoparticles (NPs) warrant deeper insight into the toxicological mechanisms induced by these materials. The present study was designed to characterize the cell death induced by carbon black (CB) and titanium dioxide (TiO2) NPs in bronchial epithelial cells (16HBE14o- cell line and primary cells) and to investigate the implicated molecular pathways.

Results
Detailed time course studies revealed that both CB (13 nm) and TiO2(15 nm) NP exposed cells exhibit typical morphological (decreased cell size, membrane blebbing, peripheral chromatin condensation, apoptotic body formation) and biochemical (caspase activation and DNA fragmentation) features of apoptotic cell death. A decrease in mitochondrial membrane potential, activation of Bax and release of cytochrome c from mitochondria were only observed in case of CB NPs whereas lipid peroxidation, lysosomal membrane destabilization and cathepsin B release were observed during the apoptotic process induced by TiO2 NPs. Furthermore, ROS production was observed after exposure to CB and TiO2 but hydrogen peroxide (H2O2) production was only involved in apoptosis induction by CB NPs.

Conclusions
Both CB and TiO2 NPs induce apoptotic cell death in bronchial epithelial cells. CB NPs induce apoptosis by a ROS dependent mitochondrial pathway whereas TiO2 NPs induce cell death through lysosomal membrane destabilization and lipid peroxidation. Although the final outcome is similar (apoptosis), the molecular pathways activated by NPs differ depending upon the chemical nature of the NPs.
Berlin's medical students' smoking habits, knowledge about smoking and attitudes toward smoking cessation counseling
Authors: Kusma Bianca , Quarcoo David , Vitzthum Karin , Welte Tobias , Mache Stefanie , Meyer-Falcke Andreas , Groneberg David A , Raupach Tobias 
Published: April 2010

Abstract

Background
Diseases associated with smoking are a foremost cause of premature death in the world, both in developed and developing countries. Eliminating smoking can do more to improve health and prolong life than any other measure in the field of preventive medicine. Today's medical students will play a prominent role in future efforts to prevent and control tobacco use.

Methods
A cross-sectional, self-administered, anonymous survey of fifth-year medical students in Berlin, Germany was conducted in November 2007. The study explored the prevalence of smoking among medical students. We assessed their current knowledge regarding tobacco dependence and the effectiveness of smoking cessation methods. Students' perceived competence to counsel smokers and promote smoking cessation treatments was also explored. Analyses were based on responses from 258 students (86.6% response rate).

Results
One quarter of the medical students surveyed were current smokers. The smoking rate was 22.1% among women, 32.4% among men. Students underestimated smoking-related mortality and the negative effect of smoking on longevity. A considerable number of subjects erroneously assumed that nicotine causes coronary artery disease. Students' overall knowledge of the effectiveness of smoking cessation methods was inadequate. Only one third of the students indicated that they felt qualified to counsel patients about tobacco dependence.

Conclusions
This study reveals serious deficiencies in knowledge and counseling skills among medical students in our sample. The curriculum of every medical school should include a tobacco module. Thus, by providing comprehensive training in nicotine dependence interventions to medical students, smokers will have access to the professional expertise they need to quit smoking.
Flux balance analysis accounting for metabolite dilution
Authors: Benyamini Tomer , Folger Ori , Ruppin Eytan , Shlomi Tomer 
Published: April 2010

AbstractFlux balance analysis is a common method for predicting steady-state flux distributions within metabolic networks, accounting for the growth demand for the synthesis of a predefined set of essential biomass precursors. Ignoring the growth demand for the synthesis of intermediate metabolites required for balancing their dilution leads flux balance analysis to false predictions in some cases. Here, we present metabolite dilution flux balance analysis, which addresses this problem, resulting in improved metabolic phenotype predictions.
Electrophysiological assessment of spectral sensitivity in adult Nile tilapia Oreochromis niloticus: evidence for violet sensitivity
Authors: Lisney T. J. , Studd E. , Hawryshyn C. W. 
Published: April 2010

SUMMARY
The cichlid fish radiations of the African Great Lakes are an important model for evolutionary biology. Cichlids have diverse colour vision systems and predominately express three cone visual pigments. However, rare populations of spectrally distinct cones have been found in a number of species, but it is not known whether they contribute to spectral sensitivity. Adult Nile tilapia, Oreochromis niloticus, an ancestral outgroup to the cichlid radiations in the Great Lakes, have three cone types: short-wavelength sensitive (SWS), medium-wavelength sensitive (MWS) and long-wavelength sensitive (LWS) cones, but evidence from microspectrophotometry and cone opsin gene expression suggests they may also have violet-sensitive (VS) cones. We used electrophysiology to assess spectral sensitivity in this species and found evidence of four sensitivity peaks in the ranges 380–420, 440–480, 500–600 and 600–680 nm, with maximal sensitivity at longer wavelengths. The continued presence of a 380–420 nm peak under long-wavelength chromatic adapting backgrounds indicates that this is due to a VS cone mechanism not the β-band of the LWS cone mechanism. Differences in spectral sensitivity curves recorded at different times of year revealed evidence of A1/A2 shifts. The presence of notches in the sensitivity curves and a multiple-mechanisms model used to assess cone contributions indicated that the curves are the result of four cone mechanisms (VS, SWS, MWS and LWS cones) and that chromatically opponent processes occur between mechanisms. The spectral transmittance of the lens steeply declines between 410–380 nm, limiting the short-wavelength limb of the VS cone. As adults, Nile tilapia appear to possess the necessary retinal mechanisms for colour vision. While maximal sensitivity to longer wavelengths is an adaptation to the wavelengths of light predominantly available in their natural habitats, their broad sensitivity range suggests that Nile tilapia possess a flexible, generalised visual system able to adapt to changes in visual environment in their highly variable natural habitat.
The mechanics of azimuth control in jumping by froghopper insects
Authors: Sutton G. P. , Burrows M. 
Published: April 2010

SUMMARYMany animals move so fast that there is no time for sensory feedback to correct possible errors. The biomechanics of the limbs participating in such movements appear to be configured to simplify neural control. To test this general principle, we analysed how froghopper insects control the azimuth direction of their rapid jumps, using high speed video of the natural movements and modelling to understand the mechanics of the hind legs. We show that froghoppers control azimuth by altering the initial orientation of the hind tibiae; their mean angle relative to the midline closely predicts the take-off azimuth. This applies to jumps powered by both hind legs, or by one hind leg. Modelling suggests that moving the two hind legs at different times relative to each other could also control azimuth, but measurements of natural jumping showed that the movements of the hind legs were synchronised to within 32 μs of each other. The maximum timing difference observed (67 μs) would only allow control of azimuth over 0.4 deg. to either side of the midline. Increasing the timing differences between the hind legs is also energetically inefficient because it decreases the energy available and causes losses of energy to body spin; froghoppers with just one hind leg spin six times faster than intact ones. Take-off velocities also fall. The mechanism of azimuth control results from the mechanics of the hind legs and the resulting force vectors of their tibiae. This enables froghoppers to have a simple transform between initial body position and motion trajectory, therefore potentially simplifying neural control.
Phosphatidylinositol 4,5-bisphosphate-dependent regulation of the output in lobster olfactory receptor neurons
Authors: Bobkov Yuriy V. , Pezier Adeline , Corey Elizabeth A. , Ache Barry W. 
Published: April 2010

SUMMARY
Transient receptor potential (TRP) channels often play a role in sensory transduction, including chemosensory transduction. TRP channels, a common downstream target of phosphoinositide (PI) signaling, can be modulated by exogenous phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] and/or diacylglycerol (DAG). Lobster olfactory receptor neurons (ORNs) express a TRP-related, non-selective, calcium/magnesium-permeable, sodium/calcium-gated cation (SGC) channel. Here we report that PIs regulate the function of the calcium-activated form of the lobster channel. Sequestering of endogenous PI(4,5)P2, either with an anti-PI(4,5)P2 antibody or by electrostatic screening with polyvalent cations, blocks the channel. Exogenous PI(3,4,5)P3 activates the channel independently of intracellular sodium and/or calcium. Exogenous non-hydrolysable DAG analogs fail to change the gating parameters of the channel, suggesting the channel is insensitive to DAG. Electrophysiological recording from lobster ORNs in situ using a panel of pharmacological tools targeting the key components of both PI and DAG metabolism (phospholipase C, phosphoinositide 4-kinase and DAG kinase) extend these findings to the intact ORN. PI(4,5)P2 depletion suppresses both the odorant-evoked discharge and whole-cell current of the cells, and does so possibly independently of DAG production. Collectively, our results argue that PIs can regulate output in lobster ORNs, at least in part through their action on the lobster SGC channel.
Insulin-induced hypoglycaemia is co-ordinately regulated by liver and muscle during acute and chronic insulin stimulation in rainbow trout (Oncorhynchus mykiss)
Authors: Polakof Sergio , Skiba-Cassy Sandrine , Choubert Georges , Panserat Stéphane 
Published: April 2010

SUMMARY
The relative glucose intolerance of carnivorous fish species is often proposed to be a result of poor peripheral insulin action or possibly insulin resistance. In the present study, data from aortic cannulated rainbow trout receiving bovine insulin (75 mIU kg−1) injections show for the first time their ability to clear glucose in a very efficient manner. In another set of experiments, mRNA transcripts and protein phosphorylation status of proteins controlling glycaemia and glucose-related metabolism were studied during both acute and chronic treatment with bovine insulin. Our results show that fasted rainbow trout are well adapted at the molecular level to respond to increases in circulating insulin levels, and that this hormone is able to potentially improve glucose distribution and uptake by peripheral tissues. After acute insulin administration we found that to counter-regulate the insulin-induced hypoglycaemia, trout metabolism is strongly modified. This short-term, efficient response to hypoglycaemia includes a rapid, coordinated response involving the reorganization of muscle and liver metabolism. During chronic insulin treatment some of the functions traditionally attributed to insulin actions in mammals were observed, including increased mRNA levels of glucose transporters and glycogen storage (primarily in the muscle) as well as decreased mRNA levels of enzymes involved in de novo glucose production (in the liver). Finally, we show that the rainbow trout demonstrates most of the classic metabolic adjustments employed by mammals to efficiently utilize glucose in the appropriate insulin context.
Detective mice assess relatedness in baboons using olfactory cues
Authors: Célérier Aurélie , Huchard Elise , Alvergne Alexandra , Féjan Delphine , Plard Floriane , Cowlishaw Guy , Raymond Michel , Knapp Leslie A. , Bonadonna Francesco 
Published: April 2010

SUMMARYThe assessment of relatedness may be crucial in the evolution of socio-sexual behaviour, because it can be associated with fitness benefits mediated by both nepotism and inbreeding avoidance. In this context, one proposed mechanism for kin recognition is ‘phenotype matching’; animals might compare phenotypic similarities between themselves and others in order to assess the probability that they are related. Among cues potentially used for kin discrimination, body odours constitute interesting candidates that have been poorly investigated in anthropoid primates so far, because of a mixture of theoretical considerations and methodological/experimental constraints. In this study, we used an indirect approach to examine the similarity in odour signals emitted by related individuals from a natural population of chacma baboons (Papio ursinus). For that purpose, we designed an innovative behavioural tool using mice olfactory abilities in a habituation–discrimination paradigm. We show that: (i) mice can detect odour differences between individuals of same sex and age class in another mammal species, and (ii) mice perceive a higher odour similarity between related baboons than between unrelated baboons. These results suggest that odours may play a role in both the signalling of individual characteristics and of relatedness among individuals in an anthropoid primate. The ‘biological olfactometer’ developed in this study offers new perspectives to the exploration of olfactory signals from a range of species.
Place learning by mechanical contact
Authors: Harrison Steven J. , Turvey Michael T. 
Published: April 2010

SUMMARYFor some animals (e.g. the night-active wandering spider) the encounters with the habitat that result in place learning are predominantly mechanical. We asked whether place learning limited to mechanical contact, like place learning in general, entails vectors tied to individual landmarks and relations between landmarks. We constructed minimal environments for blindfolded human participants. Landmarks were raised steps. ‘Home’ was a mechanically indistinct location. Travel was linear. The mechanical contacts were those of walking, stepping, and probing with a soft-tipped cane. Home-orienting activities preceded tests of finding home from a given location with landmarks unchanged or (unbeknown to participants) shifted. In a one-landmark environment, perceived home shifted in the same direction, with the same magnitude, as the shifted landmark. In an environment of two landmarks located in the same direction from home, shifting the further landmark toward home resulted in a change in home's perceived location that preserved the original ratio of distances separating home, nearer landmark, and further landmark. Both findings were invariant over the travel route to the test location and repetitions of testing. It seems, therefore, that for humans (and, perhaps, for wandering spiders), mechanical contact can reveal the vectors and relations specifying places.
Phosphorylation state of the Na+–K+–Cl− cotransporter (NKCC1) in the gills of Atlantic killifish (Fundulus heteroclitus) during acclimation to water of varying salinity
Authors: Flemmer Andreas W. , Monette Michelle Y. , Djurisic Maja , Dowd Brian , Darman Rachel , Gimenez Ignacio , Forbush Biff 
Published: April 2010

SUMMARYEuryhaline teleosts such as Atlantic killifish (Fundulus heteroclitus) are able to acclimate to changing environmental salinity by tightly regulating NaCl absorption and secretion across their gills. Many studies have examined the mechanisms responsible for long-term (days) salinity acclimation; however, much remains unknown about the mechanisms of acute (hours) salinity acclimation. In this study, we tested the hypotheses that phosphorylation of the Na+–K+–Cl− cotransporter (NKCC1) located in the basolateral membrane of the gill plays a role in acute salinity acclimation and that changes in NKCC1 phosphorylation are mediated by a cAMP–protein kinase A (cAMP–PKA) pathway. Using a phospho-specific antibody, we determined the time course of changes in total and phosphorylated NKCC1 protein during acclimation to water of various salinities. Long-term (≥14 days) acclimation of killifish to seawater (SW) and 2× SW resulted in 4- to 6-fold and 5- to 8-fold increases, respectively, in total gill NKCC1 protein relative to fish maintained in freshwater (FW). NKCC1 was found to be between 20% and 70% activated in fish, with lower average activation in fish acclimated to SW and 2× SW compared with FW fish. Increases and decreases in the fractional level of NKCC1 phosphorylation were seen within 1 h of transfer of fish to water of higher and lower salinity, respectively, consistent with a regulatory role of phosphorylation prior to an increase in the biosynthesis of NKCC1; large changes in protein expression of NKCC1 were observed over periods of hours to days. We found that NKCC1 phosphorylation is acutely regulated in the killifish gill in response to changing environmental salinity and that phosphorylation in excised gills increases in response to forskolin stimulation of the cAMP–PKA pathway. The role of phosphorylation is further underscored by the observation that mRNA expression of sterile 20 (Ste20)-related proline–alanine-rich kinase (SPAK) changes with salinity acclimation, being 2.7-fold greater in SW-acclimated killifish relative to FW fish. Overall, these results demonstrate an important role of NKCC1 phosphorylation in the gill of Atlantic killifish during acute salinity acclimation.
Effect of acute exposure to low environmental calcium on respiration and locomotion in Lymnaea stagnalis (L.)
Authors: Dalesman Sarah , Lukowiak Ken 
Published: April 2010

SUMMARY
Environmental calcium is a major factor affecting the distribution of freshwater gastropods. Whilst the effects on growth and morphology are fairly well understood, little is known about how calcium availability affects other aspects of gastropod biology. Lymnaea stagnalis (L.) is considered a calciphile and exhibits reduced growth and survival in environments containing less than 20 mg l−1 Ca2+. Many freshwater systems exhibit fluctuations in calcium concentration over time: where calcium levels are normally high there may be periods of low [Ca2+], for example following periods of flooding. Here we examined the effects of acute periods of low (20 mg l−1) environmental calcium on the physiology and behaviour of L. stagnalis, specifically measuring how locomotion and respiration differ between high calcium (80 mg l−1) and low calcium (20 mg l−1) environments. We found that in a low calcium environment crawling speed is reduced, and that this coincides with an increase in cutaneous respiration, indicating that the increased metabolic demands of calcium acquisition at low [Ca2+] reduce the energy available for locomotion. Conversely we found a decrease in aerial respiration in hypoxic conditions in the low calcium relative to the high calcium environment. In conclusion, we found that acute exposure to low environmental calcium has a highly significant effect on locomotion and respiration, which may have consequences for snail fitness when no morphological effects are apparent.
ATP-induced temperature independence of hemoglobin–O2 affinity in heterothermic billfish
Authors: Weber Roy E. , Campbell Kevin L. , Fago Angela , Malte Hans , Jensen Frank B. 
Published: April 2010

SUMMARY
The inverse relationship between temperature and hemoglobin–O2 affinity resulting from the exothermic nature of heme oxygenation favors O2 unloading from blood to warm, metabolically active tissues. However, this temperature sensitivity is maladaptive, and commonly countered in regional heterotherms, where it may hamper unloading (e.g. in cold extremities of arctic mammals) or increase the diffusive arterio-venous short-circuiting of O2 (e.g. in counter-current heat exchangers of warm swimming muscles of tuna). We hypothesized analogous blood specializations in heterothermic billfish, whose warm eyes and brains increase the temporal resolution of vision, and measured hemoglobin–O2 binding properties in three species over a wide pH range, at two temperatures, and in the absence and presence of the major red cell effector, ATP, permitting detailed assessment of overall oxygenation enthalpies (ΔH′) and contributions from oxygenation-linked proton and ATP dissociation. Billfish express multiple isohemoglobins with similar O2 affinities and pronounced sensitivities to pH and ATP. Compared with the moderate effects associated with proton dissociation upon oxygenation, dissociation of ATP and coupled extra Bohr protons virtually obliterates the temperature sensitivities. At pH 7.4, where this effect is maximal, ATP changes ΔH′ values of blue marlin, striped marlin and shortbill spearfish hemoglobins from −39, −49 and −44 kJ mol−1 O2, respectively, to +26, +4 and −7 kJ mol−1. Thus in addition to allosterically modulating hemoglobin–O2 affinity, ATP diminishes its temperature sensitivity, reducing deleterious arterio-venous short-circuiting of oxygen in the cranial billfish heat exchangers. The mechanism underlying this reduction in oxygenation enthalpy differs fundamentally from that in tuna, supporting independent evolution of this trait in these scombroid lineages.
Serotonin prolongs survival of encapsulated pond snail embryos exposed to long-term anoxia
Authors: Shartau Ryan B. , Tam Rose , Patrick Spencer , Goldberg Jeffrey I. 
Published: April 2010

SUMMARYEmbryos of the pond snail, Helisoma trivolvis, develop bilateral serotonergic neurons that innervate ciliary bands and stimulate cilia-driven rotation. This behaviour is postulated to increase oxygen availability during hypoxia by mixing the capsular fluid. We hypothesised that the stimulation of ciliary-driven rotation by serotonin (5-HT) enhances the survival of embryos during prolonged hypoxia. Embryo rotation and survival were monitored in different levels of oxygen for 24–48 h while in the presence or absence of 5-HT (100 μmol l−1) or a 5-HT antagonist (50 μmol l−1). Long-term hypoxia caused delayed embryonic development that appeared morphologically normal. Hypoxia also induced a transient increase in rotation rate in embryos exposed to artificial pond water (APW) or 5-HT that lasted around 3 h. 5-HT-treated embryos had an elevated rotation rate over embryos in APW throughout the long-term exposure to hypoxia. Long-term anoxia also induced a transient increase in rotation rate in embryos exposed to APW or 5-HT. Rotation ceased in embryos exposed to APW by 13 h but persisted in 5-HT-treated embryos for up to 40 h. Fifty percent mortality was reached at 9 h of anoxia in embryos in APW and at 24 h in 5-HT-treated embryos. The 5-HT antagonist mianserin partially inhibited the 5-HT enhancement of rotation but not the prolongation of survival in anoxia. The ability of 5-HT to prolong survival in anoxia reveals a 5-HT-activated metabolic pathway that liberates an alternative energy source.