bluuebunny/crossref_metadata_2025 huggingface dataset:
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

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

Many 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

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

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

The 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

For 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

Euryhaline 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

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

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

Embryos 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.
Gender expression and group size: a test in a hermaphroditic and a gonochoric congeneric species of Ophryotrocha (Polychaeta)
Authors: Schleicherova D. , Lorenzi M. C. , Sella G. , Michiels N. K.
Published: April 2010

Hermaphroditism and gonochorism are two contrasting forms of sexuality. Hermaphroditic species are generally seen as species adapted to conditions of low density, stabilized by poor mate search efficiency and high costs of searching. They can adjust allocation of reproductive resources to each sex function in response to current social conditions, making reproduction more efficient, at least in principle. By contrast, gonochorism (separate sexes) is advantageous when mates are frequent, making it ineffective to maintain two sex functions in a single individual. This, however, also rules out the need for a flexible response to mating opportunities as known for hermaphrodites. In the hermaphroditic marine polychaete worm Ophryotrocha diadema we showed earlier that group size is assessed through a chemical cue. In this study we verified the accuracy of the response to gradients of the chemical cue used to assess group size by O. diadema by checking reduction in egg production as the group of partners increases, as expected according to sex allocation theory. Furthermore we compared the effect of such a gradient with a similar gradient in a closely related gonochoric species (O. labronica). Here sex allocation adjustment is not predicted, thus an adaptive change in egg production in response to group-size cues is not expected. In fact, our results show that the group-size effect only occurs in O. diadema and not in O. labronica. Moreover, our study provides evidence of high perceptual abilities of chemical cues in O. diadema, suggesting that perceiving social cues and adjusting sex allocation appropriately are special properties of hermaphrodites.
Algorithms for Coxianization of Phase-Type Generators
Authors: He Qi-Ming , Zhang Hanqin , Xue Jungong
Published: April 2010

This paper develops algorithms for finding Coxian generators to phase-type (PH)-majorize a PH-generator T with only real eigenvalues. In the first part of this paper, we investigate matrices S and P satisfying TP = PS and Pe = e. Conditions on T are identified for S to be an ordered Coxian generator and for P to be nonnegative, which consequently implies that S PH-majorizes T. It is shown that every PH-generator with only real eigenvalues is PH-majorized by some Coxian generator. In the second part of this paper, the results on S and P and the conditions on T are used to develop efficient algorithms for Coxianization of PH-generators. Numerical examples are presented for a comparison between the developed algorithms.
A randomized controlled trial of a feedback method for improving empathic accuracy in psychotherapy
Authors: Sripada Bhaskar N. , Henry David B. , Jobe Thomas H. , Winer Jerome A. , Schoeny Michael E. , Gibbons Robert D.
Published: April 2010

Objectives. To develop and evaluate a feedback method for reducing empathic errors in psychotherapy.

Design. Randomized controlled trial conducted in a university‐affiliated out‐patient psychiatric clinic.

Methods. Sixteen non‐psychotic patients treated for Axis I disorders by 12 psychiatry residents were randomly assigned to intervention and control conditions. In both conditions, at the end of each session, patients rated their own functioning on the Global Assessment of Functioning scale, and therapists predicted patients' ratings. Patients predicted their therapist's accuracy and therapists rated their confidence in their own predictions. In the intervention condition, therapists and patients reviewed their respective ratings from the previous session together. In the control condition, ratings were given directly to the investigator without being reviewed by either patients or therapists.

Results. Therapists in the intervention condition showed greater overall accuracy than controls as well as evidence of increasing empathy later in therapy on the Barrett‐Lennard empathy subscale. Patients in the control group perceived their therapists as significantly more or less accurate than was warranted according to the accuracy measure (over‐/under‐idealization). Therapists in the control group were more likely than those in the intervention group to overestimate their own accuracy (overconfidence). Affective responses to the instrument were positive overall and did not differ by condition.

Conclusion. An intervention such as the one tested in this study may be a practical and useful method for improving accuracy of understanding in a variety of training and clinical settings.
A Family Study of Adult Twins with and without a History of Childhood Abuse: Stability of Retrospective Reports of Maltreatment and Associated Family Measures
Authors: Nelson Elliot C. , Lynskey Michael T. , Heath Andrew C. , Madden Pamela A. F. , Martin Nicholas G.
Published: April 2010

Childhood sexual abuse (CSA) and physical abuse (CPA) are well-established risk-factors for a wide of range of proximal and distal outcomes. The lack of availability of an optimal design for examining abuse and its consequences has resulted in the use of various approaches, each having its own limitations. We describe the Childhood Trauma Study, which ascertained families from a large young adult Australian twin cohort on the basis of twins' responses to screening questions assessing CSA and CPA. We report data from 3407 participants including twins, non-twin siblings, and their parents. Our data demonstrate the feasibility of using a comprehensive assessment to evaluate retrospective history of childhood abuse in an adult sample. We observed that risk for each form of abuse increased incrementally with the number of parents with alcohol problems. Psychometric properties of our measures of CSA and CPA including reasonable long-term stability, construct validity, and evidence of familial corroboration compare favorably with those of other reports in which samples were considerably younger and assessments were repeated over shorter intervals.
No Evidence that Social Desirability Response Set Explains the General Factor of Personality and Its Affective Correlates
Authors: Rushton J. Philippe , Erdle Stephen
Published: April 2010

In two studies, the General Factor of Personality (GFP) remained intact after controlling for the Lie scale from the Eysenck Personality Questionnaire, despite the Lie Scale showing significant correlations with the GFP defining traits. In Study 1, a re-analysis of 29 self-ratings from 322 pairs of twins (644 individuals) yielded a GFP both before and after controlling for social desirability. In Study 2, four measures of affect in 133 university students loaded on a GFP both before and after controlling for social desirability such that those high on the GFP were high in self-esteem and positive affect and low in depression and negative affect. These results join those from other studies failing to find evidence that the GFP is merely an artifact of evaluative bias.
Beitrag der Durchflusszytometrie zur Diagnose und Differentialdiagnose der Thrombozytopenie / Contribution of flow cytometry to the diagnosis and differential diagnosis of thrombocytopenia
Authors: Mauerer Richard , Gruber Rudolf
Published: April 2010

Thrombozytopenien sind häufig und werden nicht nur bei Patienten mit klinischer Blutungsneigung, sondern auch bei der labordiagnostischen Abklärung anderer Erkrankungen oder bei Routineuntersuchungen klinisch gesunder Personen als Zufallsbefund gefunden. Die Ermittlung der Ursache der Thrombopenie ist daher von essentieller Bedeutung. Labordiagnostisch steht dafür ein breites Angebot unterschiedlicher analytischer Methoden zur Verfügung. Ein großer Vorteil der Durchflusszytometrie besteht darin, dass nur eine vergleichsweise geringe Menge Patientenprobe benötigt wird, was vor allem bei der Abklärung ausgeprägt thrombopenischer oder pädiatrischer Proben eine Rolle spielt. Aus diesem Grund wird auch die immunologische Bestimmung der Thrombozytenzahl am Durchflusszytometer derzeit als Referenzmethode empfohlen, um eine exakte und möglicherweise therapieentscheidende Quantifizierung sehr niedriger Thrombozytenzahlen zu erreichen. Auch die Differenzierung Thrombozytenbildungsstörung vs. Verbrauch durch die Bestimmung unreifer Plättchen ist eine etablierte Methode, welche durch die routinemäßige Verfügbarkeit dieses Parameters an modernen Blutbildautomaten an Bedeutung gewinnen wird. Eine weitere Anwendung der Durchflusszytometrie besteht im Nachweis von immunologisch vermittelten Thrombopenien, wobei die Antikörper wie bei der Autoimmunthrombopenie gegen Glykoproteine der Thrombozytenoberfläche oder wie bei der Heparin-induzierten Thrombopenie (HIT) gegen einen Komplex aus Heparin und Plättchenfaktor 4 gerichtet sein können. Darüber hinaus kommen durchflusszytometrische Assays auch in der Abklärung der seltenen kongenitalen Thrombopenien zum Einsatz. Beim Bernard-Soulier-Syndrom sichern sie die Diagnose, bei anderen Erkrankungen können sie zumindest den Weg für eine weiterführende Diagnostik weisen.

Auf die Möglichkeiten der Durchflusszytometrie bei der Abklärung von Leukämien und Lymphomen, die durch verdrängende Prozesse im Knochenmark häufig zu einer Thrombopenie führen, wird in diesem Beitrag nicht eingegangen.
Überwachung der Clopidogrel-Therapie mit Hilfe der Mehrfach-Elektroden Plättchen-Aggregometrie / Monitoring of clopidogrel treatment by multiple electrode platelet aggregometry
Authors: Behr Tobias , Behr Werner , von Scheidt Wolfgang
Published: April 2010

Mangelndes Ansprechen auf Clopidogrel ist eine Hauptursache für Komplikationen nach Implantation eines Koronarstents. Mehrfach-Elektroden Plättchen-Aggregometrie (MEA) mit Hilfe des Multiplate®-Systems scheint eine geeignete Methode für die Kontrolle der Clopidogrel-Therapie zu sein. Wir validierten die Methode, indem wir MEA-Messungen aus Hirudinblut bei folgenden Gruppen durchführten: 150 gesunde Testpersonen, um die MEA-Referenzbereiche festzulegen; 75 hämatologische Patienten mit Anämie/Thrombopenie, um den Einfluss von Hämatokrit (Hk) und Thrombozytenzahl auf die MEA-Werte zu bestimmen; 1005 Patienten nach perkutaner Koronarintervention (PCI) und Verabreichung einer 600 mg-Clopidogrel-loading-dose, um die Reproduzierbarkeit der Ergebnisse unter klinischen Bedingungen zu testen. Unterschiedliche Methoden bei Blutgewinnung und Transport beeinflussen die MEA-Werte nicht, wenn die Probe vor der Messung 30 Minuten ruhig liegt. Die Analyse muss innerhalb von 3 Stunden nach Blutentnahme erfolgen. Bei Patienten mit einem Hk ≤0,30 L/L oder Thrombozyten ≤100/nL sind keine zuverlässigen Ergebnisse möglich. Ein Ansprechen auf Clopidogrel ist anzunehmen, wenn der ADP-Wert den unteren Referenzbereich (Männer: 32 U, Frauen: 46 U) unterschreitet. Da die Clopidogrel-loading-dose auch zur Abnahme des Thrombin-Rezeptor-Activating Peptid (TRAP)-Wertes führt, kann der Responder-Status nur eindeutig festgelegt werden, wenn der TRAP-Wert >20 U und das TRAP/ADP-Verhältnis >3 sind. Das Clopidogrel-Monitoring sollte in den ersten 24 Stunden nach PCI erfolgen, auch wenn ca. 12% der Ergebnisse unklar sind und kontrolliert werden müssen. Zusammenfassend ist die MEA-Messung bei Beachtung der präanalytischen Bedingungen und des Blutbildes eine geeignete Methode, um eine Clopidogrel-Response zu erkennen. Um eine valide Beurteilung zu gewährleisten, sollte der TRAP-Test gleichzeitig durchgeführt werden.
Standardisierung von Laborergebnissen: Ergebnisquotient / Standardization of laboratory results: quotient reporting
Authors: Haeckel Rainer , Wosniok Werner , Hoffmann Georg ,   aus den Arbeitsgruppen Richtwerte (Sprecher: Eberhard Gurr) und Bioinformatik (Sprecher: Georg Hoffmann) der DGKL
Published: April 2010

Die Vergleichbarkeit von quantitativen Ergebnissen aus verschiedenen Laboratorien ist trotz erheblicher Bemühungen vieler wissenschaftlicher Fachgesellschaften um Standardisierung noch unbefriedigend. Als Beitrag zur Verbesserung der Situation hat die Arbeitsgruppe „Richtwerte“ der DGKL frühere Vorschläge einer z-Transformation aufgegriffen und diese mit einer Skalenverschiebung und Umskalierung der biologischen Standardabweichung kombiniert nach dem Modell des Intelligenz-Quotienten. Ergebnisquotienten sollten zusammen mit den konventionellen Ergebnissen im Befundbericht ausgegeben werden, wie an einigen Beispielen mit einer farblichen Kodierung demonstriert wird.
Specific Gravity of Expansive Chromium Ore Processing Residue with Complex Microstructure
Authors: Millspaugh Andrew M. , Tinjum James M. , Boecher Timothy A.
Published: April 2010

Specific gravity tests were performed on chromium ore processing residue (COPR), an expansive industrial byproduct of the historical processing of chromite ore, to determine if the complexity and heterogeneity of the particle microstructure may cause erroneous specific gravity results using ASTM D854-06 Method B as the baseline procedure. In complex, reactive industrial residuals such as COPR, specific gravity is an important indicator of the extent of weathering that has occurred. Specific gravity for weathered hard-brown (HB) COPR significantly differs from that of unweathered gray-black (GB) COPR, and laboratory testing can indicate the position of COPR along the GB to HB pathway. The difference between a “true” and an “apparent” specific gravity that accounts for the inclusion of closed pores was determined. Oven-drying of COPR at the ASTM standard temperature of 110±5°C does not cause mineral dehydration to affect specific gravity results. The apparent (avg.=3.146) and true (avg.=3.355) specific gravities of GB COPR are statistically different and should be reported as such. Pre-processing of GB COPR by mechanical grinding is necessary to open intraparticle voids, determined to be 6.2 % by volume, to the atmosphere and thus approach the true specific gravity.
Evaluation of the Critical Air-Void System Parameters for Freeze-Thaw Resistant Ternary Concrete Using the Manual Point-Count and the Flatbed Scanner Methods
Authors: Radlinski Mateusz , Olek Jan , Zhang Qinghuan , Peterson Karl
Published: April 2010

This research was conducted to verify whether the semi-automatic method of air-void system characterization (using a flatbed scanner) could be used in lieu of the manual (ASTM C457) method. This research objective was accompanied by evaluating the critical air-void system parameters required to ensure freeze-thaw resistance of ternary concrete containing ordinary portland cement (OPC), 20 % of fly ash (FA), and 5 % of silica fume (SF). It was observed that, due to adverse effect of high superplasticizer dosage on air-void system quality (particularly on specific surface), the majority of high slump ternary mixtures exhibited poor freeze-thaw resistance, even if spacing factor was below the 0.20 mm recommended value. However, when the ternary mixtures were prepared with slump below the limit commonly specified for bridge deck applications (190 mm), the critical air-void system parameters of the OPC/FA/SF concrete were comparable to those typically associated with adequate quality air-void system in conventional concrete. Furthermore, since the critical value of specific surface was independent of slump (i.e., superplasticizer dosage), specific surface appeared to be more objective and reliable predictor of freeze-thaw resistance than spacing factor. When comparing the semi-automatic and manual methods of air-void system characterization, a reasonably strong agreement was obtained for such parameters as air content, void frequency, and spacing factor. Although the results of these methods did not match perfectly, the data suggested that the flatbed scanner technique could be efficiently used for discerning between freeze-thaw durable and non-durable concretes.
Seasonal effects on gene expression, cleavage timing, and developmental competence of bovine preimplantation embryos
Authors: Gendelman M , Aroyo A , Yavin S , Roth Z
Published: April 2010

We examined the association between season and expression of genes involved in early embryonic development with an emphasis on cleavage rate and timing of the first embryonic cleavage. In Exp. 1, oocytes were aspirated during the cold (Dec–Apr) and hot (May–Nov) seasons. Matured oocytes were chemically activated and culturedin vitro. The developmental peak to the two- and four-cell stages occurred earlier, with a higher proportion of first-cleaved embryos, during the cold season relative to the hot season (P<0.01). In Exp. 2, a time-lapse system was employed to characterize the delayed cleavage noted for the hot season. Cleavage to the two-cell stage occurred in two distinct waves: early cleavage occurred between 18 and 25 h post activation, and late cleavage occurred between 27 and 40 h post activation. In Exp. 3, oocytes were aspirated during the cold and hot seasons, maturedin vitro, fertilized, and cultured for 8 days. In each season, early- and late-cleaved two-cell stage embryos were collected. Total RNA was isolated, and semi-quantitative and real-time PCRs were carried out with primers forGDF9,POU5F1, andGAPDHusing18S rRNAas the reference gene. In both seasons, the expression of all examined genes was higher (P<0.05) in early- versus late-cleaved embryos.POU5F1expression was higher (P<0.05) in early-cleaved embryos developed in the cold season versus the hot season counterparts. The findings suggest a deleterious seasonal effect on oocyte developmental competence with delayed cleavage and variation in gene expression.
Screening for type 2 diabetes and prediabetes – methodological concerns and feasibility in Hungary
Authors: Jermendy György , Hidvégi Tibor , Vándorfi Győző , Winkler Gábor
Published: April 2010

A 2-es típusú diabetes kórfejlődése jellemző módon időben elhúzódó és lappangó, olykor a manifeszt betegség kezdeti stádiuma is meglehetősen tünetszegény. Ez megteremti az alapját a szűrővizsgálattal történő betegségfelismerésnek. Szűrővizsgálattal nemcsak a 2-es típusú diabetes, hanem kórmegelőző állapota (összefoglaló néven praediabetes) is felismerhető. A szűrővizsgálat céljára napjainkban az úgynevezett kockázatalapú, kétlépcsős módszer a leginkább elfogadott: az első lépcsőben kérdőív segítségével azonosíthatók a fokozott kockázatú egyének, a második lépcsőben ez utóbbiak körében vércukor-meghatározásra kerül sor. A kérdőívek közül a FINDRISC (Finnish Diabetes Risk Score) használata terjedt el a legtöbb országban, az első hazai tapasztalatok is kedvezőek alkalmazásával kapcsolatban. A szűrővizsgálat megteremti a korai diabetesesetek azonosítását, illetve a primer prevenció lehetőségét. Mindez végül elvezethet a 2-es típusú diabetes előfordulási gyakoriságának csökkenéséhez. Helyes lenne, ha ez az egészségügyi-társadalmi aktivitás hazánkban is – más országokhoz hasonlóan – nemzeti diabetesprogram keretei között valósulna meg.
Lymph scrotum: an unusual urological presentation of lymphatic filariasis. A case series study
Authors: Aguiar-Santos Ana Maria , Leal-Cruz Marcela , Netto Maria José , Carrera Arturo , Lima Guilherme , Rocha Abraham
Published: April 2010

Lymphatic filariasis (LF) causes a wide range of clinical signs and symptoms, including urogenital manifestations. Transmission control and disability/morbidity management/control are the two pillars of the overall elimination strategy for LF. Lymph scrotum is an unusual urological clinical presentation of LF with important medical, psychological, social and economic repercussions. A retrospective case series study was conducted on outpatients attended at the National Reference Service for Filariasis, in an endemic area for filariasis (Recife, Brazil), between 2000 and 2007. Over this period, 6,361 patients were attended and seven cases with lymph scrotum were identified. Mean patient age was 45 years (range, 26 to 64 years). Mean disease duration was 8.5 years (range, two to 15 years). All patients had evidence of filarial infection from at least one laboratory test (parasitological, antigen investigation or "filarial dance sign" on ultrasound). Six patients presented histories of urological surgery. The authors highlight the importance of the association between filarial infection and the inadequate surgical and clinical management of hydrocele in an endemic area, as risk factors for lymph scrotum. Thus, filarial infection should be routinely investigated in all individuals presenting urological morbidity within endemic areas, in order to identify likely links in the transmission chain.
A serological study of cysticercosis in patients with HIV
Authors: Parija Subhash Chandra , Gireesh A.R.
Published: April 2010

Neurocysticercosis (NCC) has attained the importance of one of the most common cause of focal brain lesions in patients infected with HIV (human immunodeficiency virus). Adequate data regarding the rate of this co-infection is lacking. Therefore, the present study was carried out to determine the prevalence of cysticercosis among HIV patients residing in Puducherry or its neighboring districts of Tamil Nadu State, India. A total of one hundred blood samples were collected from HIV seropositive cases visiting JIPMER hospital, Puducherry, between June 2007 and May 2008. Enzyme immunotransfer blot (EITB) and enzyme linked immunosorbent assay (ELISA) were used to demonstrate anti- T. solium larval stage antibodies and Co-agglutination (Co-A) test was used to detect T. solium larval stage antigens in sera. Two HIV seropositive cases were found positive for anti-T. solium larval stage antibody by EITB and four were positive by ELISA. Only one sample was positive by both EITB and ELISA. No serum sample was found positive for T. solium larval stage antigen by Co-A test. The overall seropositivity detected by all the methods was 5% in this study group. The accurate clinical diagnosis of NCC in HIV is difficult due to deranged immunological parameters in the HIV infected patients. The results of this study provides important data on the prevalence of cysticercosis in HIV positive patients in Puducherry and neighboring areas which was previously unknown. This study will also increase awareness among physicians and public health agencies about T. solium cysticercosis in the selected group.
Extended-spectrum beta-lactamases among Enterobacteriaceae isolated in a public hospital in Brazil
Authors: Dropa Milena , Balsalobre Livia C. , Lincopan Nilton , Mamizuka Elsa M. , Murakami Thays , Cassettari Valéria C. , Franco Fábio , Guida Stella M. , Balabakis Angelica J. , Passadore Lilian F. , Santos Silvia R. , Matté Glavur R. , Matté Maria H.
Published: April 2010

Extended-spectrum β-lactamases (ESBL) in enterobacteria are recognized worldwide as a great hospital problem. In this study, 127 ESBL-producing Enterobacteriaceae isolated in one year from inpatients and outpatients at a public teaching hospital at São Paulo, Brazil, were submitted to analysis by PCR with specific primers for blaSHV, blaTEM and blaCTX-M genes. From the 127 isolates, 96 (75.6%) Klebsiella pneumoniae, 12 (9.3%) Escherichia coli, 8 (6.2%) Morganella morganii, 3 (2.3%) Proteus mirabilis, 2 (1.6%) Klebsiella oxytoca, 2 (1.6%) Providencia rettgeri, 2 (1.6%) Providencia stuartti, 1 (0.8%) Enterobacter aerogenes and 1 (0.8%) Enterobacter cloacae were identified as ESBL producers. BlaSHV, blaTEM and blaCTX-M were detected in 63%, 17.3% and 33.9% strains, respectively. Pulsed field gel eletrophoresis genotyping of K. pneumoniae revealed four main molecular patterns and 29 unrelated profiles. PCR results showed a high variety of ESBL groups among strains, in nine different species. The results suggest the spread of resistance genes among genetically different strains of ESBL-producing K. pneumoniae in some hospital wards, and also that some strongly related strains were identified in different hospital wards, suggesting clonal spread in the institutional environment.
Preliminary investigation of Culicidae species in South Pantanal, Brazil and their potential importance in arbovirus transmission
Authors: Pauvolid-Corrêa Alex , Tavares Fernando Neto , Alencar Jeronimo , Silva Julia dos Santos , Murta Michele , Serra-Freire Nicolau Maués , Pellegrin Aiesca Oliveira , Gil-Santana Hélcio , Guimarães Anthony Érico , Silva Edson Elias da
Published: April 2010

In view of the high circulation of migratory birds and the environmental and climatic conditions which favor the proliferation of arthropods, the Brazilian Pantanal is susceptible to circulation of arboviruses. However, the amount of data concerning arbovirus vectors in this area is scarce; therefore the aim of this study was to conduct a preliminary investigation of Culicidae species in the Nhecolândia Sub-region of South Pantanal, Brazil and their potential importance in the arbovirus transmission. A total of 3684 specimens of mosquitoes were captured, 1689 of which caught in the rainy season of 2007, were divided into 78 pools and submitted to viral isolation, Semi-Nested RT-PCR and Nested RT-PCR, with a view to identifying the most important arboviruses in Brazil. Simultaneously, 70 specimens of ticks found blood-feeding on horses were also submitted to the same virological assays. No virus was isolated and viral nucleic-acid detection by RT-PCR was also negative. Nevertheless, a total of 22 Culicidae species were identified, ten of which had previously been reported as vectors of important arboviruses. The diversity of species found blood-feeding on human and horse hosts together with the arboviruses circulation previously reported suggest that the Nhecolândia Sub-region of South Pantanal is an important area for arbovirus surveillance in Brazil.
Characterization of a Hepatitis B virus strain in southwestern Paraná, Brazil, presenting mutations previously associated with anti-HBs Resistance
Authors: Bertolini Dennis Armando , Ribeiro Patrícia Cristiane , Lemos Marcílio Figueiredo , Saraceni Cláudia Patara , Pinho João Renato Rebello
Published: April 2010

The present study investigated if hepatitis B virus (HBV) mutants circulate in the southwestern region of the State of Paraná, Brazil, by analyzing samples from children who received immunoprophylaxis but were born to HBV carrier mothers. Samples from 25 children were screened for HBV serum markers and for HBV DNA by PCR. Only one sample was positive for HBsAg, anti-HBs and HBV DNA, although the child had been vaccinated. Analysis of the S gene sequence of this sample showed the presence of a proline at position 105, a serine at position 114, three threonines at positions 115, 116 and 140, and a glutamine at position 129. The presence of these amino acids, except for serine at position 114, has been related to monoclonal or polyclonal therapy with anti-HBs after liver transplantation, whereas the presence of threonine at position 116 has been described in immunized children from Singapore. This finding demonstrates the possible circulation of HBV strains resistant to hepatitis B immunoprophylaxis in southwestern Paraná, Brazil. The genotype of the sample was identified as genotype D, which is frequently found in the region studied. Since 36% of the children had received incomplete or no immunoprophylaxis, more extensive follow-up of children born to HBsAg-positive mothers is needed.
Analysis of the Outer Surface of Platinum-Gold Catalysts by Low-Energy Ion Scattering
Authors: Brongersma Hidde H. , Grehl Thomas , Schofield Emma R. , Smith Richard A. P. , ter Veen Hendrik R. J.
Published: April 2010

Low-energy ion scattering (LEIS) can be used to selectively analyse the atomic composition of the outer atomic layer of a catalyst, i.e., precisely the atoms that largely determine its activity and selectivity. It is shown how a new development in LEIS significantly improves its mass resolution. Using this advanced separation and quantification of signals from platinum and gold, the atomic composition of the outer surface of a realistic supported platinum-gold bimetallic system can be determined for the first time.