bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pheochromocytoma-Induced Cardiomyopathy is Modulated by the Synergistic Effects of Cell-Secreted Factors
Authors: Mobine Hector R. , Baker Aaron B. , Wang Libin , Wakimoto Hiroko , Jacobsen Kurt C. , Seidman Christine E. , Seidman J.G. , Edelman Elazer R. 
Published: February 2009

Background—Pheochromocytomas are rare tumors derived from the chromaffin cells of the adrenal medulla. Although these tumors have long been postulated to induce hypertension and cardiomyopathy through the hypersecretion of catecholamines, catecholamines alone may not fully explain the profound myocardial remodeling induced by these tumors. We sought to determine whether changes in myocardial function in pheochromocytoma-induced cardiomyopathy result solely from catecholamines secretion or from multiple pheochromocytoma-derived factors.Methods and Results—Isolated cardiomyocytes incubated with pheochromocytoma-conditioned growth media contracted at a higher frequency than cardiomyocytes incubated with norepinephrine (NE) only. Sprague-Dawley rats and black-6 mice were implanted with agarose-encapsulated pheochromocytoma (PC12) cells, dihydroxyphenylalanine decarboxylase knock-out PC12 cells deficient in NE (PC12-KO), or NE-secreting pumps. PC12 cell implantation increased left ventricular dilation by 35�6% and 9.6�1.4% and reduced left ventricular fractional shortening by 20�3% and 28�4% in rats and mice compared with animals dosed only with NE, respectively. Elimination of NE secretion in PC12-KO cells induced neither cardiac dilation (3.9%�1.8% increase versus control) nor changes in (1.9%�0.4% reduction) fractional shortening compared to controls.Conclusions—Pheochromocytomas induce a greater degree of cardiomyopathy than equivalent doses of NE, suggesting pheochromocytoma-induced cardiomyopathy is not solely mediated by NE, rather pheochromocytoma secretory factors in combination with catecholamines act synergistically to induce greater cardiac damage than catecholamines alone.
Prey chemical discrimination by a diploglossine lizard, the giant Hispaniolan galliwasp (Celestus warreni)
Authors: Cooper William , Bradley Kelly 
Published: February 2009

AbstractPrey chemical discrimination, the ability to respond differentially to prey chemicals and control stimuli, enables many squamate reptiles to locate and identify prey using chemical cues sampled by tongue-flicking and analyzed by vomerolfaction. Among lizards this ability is limited to species that are active foragers having insectivorous/carnivorous diets and to omnivores and herbivores, even those derived from ancestral ambush foragers. We experimentally studied responses by hatchlings of giant Hispaniolan galliwasps, Celestus warreni, which appear to have a strict animal diet and are putatively active foragers, to prey chemicals and control substances. More individuals tongue-flicked in the cricket condition than the water condition. Response strength indicated by the tongue-flick attack score, a composite index of response strength based on number of tongue-flicks, biting (one lizard) and latency to bite, was greater in response to cricket stimuli than plant (lettuce) stimuli, cologne or distilled water. Thus, the galliwasps exhibited prey chemical discrimination. Celestus warreni, the first representative of Diploglossinae to be tested, exhibits chemosensory behavior similar to that of other anguids. Although no quantitative data on foraging mode are available, another diploglossine, Diploglossus vittatus, is an active forager. The limitation of prey chemical discrimination to active foragers among lizards with animal diets lend further support to the likelihood that C. warreni is an active forager. The galliwasps did not exhibit plant chemical discrimination.
Preferred temperatures of Podarcis vaucheri from Morocco: intraspecific variation and interspecific comparisons
Authors: Veríssimo Carla V. , Carretero Miguel A. 
Published: February 2009

AbstractPreferred body temperatures (Tp) were analysed in the lacertid Podarcis vaucheri, from S. Iberia and N. Africa which has been recently revalidated as a full species within the P. hispanica complex. Adult lizards from a Moroccan population were exposed to a thermal gradient and Tp was measured at ten time intervals. Intraspecific Tp variation due to sex and reproductive condition (Tp: non-pregnant females ≥ males ≥ pregnant females) and time of the day (Tp: early morning > rest of the day) was detected. Pregnant females tended to increase their Tp after egg-laying. This dependence on the reproductive condition parallels findings in other lacertids. Class-by-class comparisons between P. vaucheri and P. (hispanica) liolepis from NE Iberia, analysed with the same methodology, revealed higher Tp values in P. vaucheri (non-pregnant females). Although further research is needed to determine the evolutionary pattern of the Tp divergence in this group, these results are compatible with the thermal rigidity hypothesis reinforcing the view of P. hispanica s.l. as an artificial assemblage.
Studies on specialized epidermal derivatives in iguanian lizards: II. New data on the scalation of the Malagasy iguanas of the genus Oplurus (Sauria: Iguanidae)
Authors: Dujsebayeva Tatjana , Ananjeva Natalia , Böhme Wolfgang , Wagner Philipp 
Published: February 2009

Abstract
The details of the ventral scalation were examined in adult and young
specimens of seven species of the Malagasy iguanids of the genera Chalarodon
Peters, 1854 and Oplurus Cuvier, 1829, both visually and using light
microscopy. For the first time, we report data on the topography, morphology
and histology of epidermal glandular structures of the genus Oplurus. The
modified swollen scales, callous-like in appearance, were described in the
abdominal, pre-cloacal and femoral integument. Histological investigation
confirmed a presence of the epidermal generation glands of the escutcheon
type. In the lizards of the genus Oplurus the epidermal glands are mainly
male characteristic, although partially modified ventral scales of the
females suggest that they also have a potential capability to production of
epidermal gland generation. A biological role of these scales is unclear, as
well as their possible relations to lizard's ecology and behaviour.
Ontogenetic and sexual variation in the coloration of the lacertid lizards Iberolacerta monticola and Podarcis bocagei. Do the females prefer the greener males?
Authors: Galán Pedro 
Published: February 2009

AbstractChanges in the coloration of the lacertid lizards Iberolacerta monticola and Podarcis bocagei with age in populations from NW Spain are described. The onset of sexual maturity in P. bocagei males involves a change in the ventral (yellow) and dorsal (green) colorations, which is different from immature males (dorsally brownish in color). In I. monticola males, the ventral coloration also changes to a deep green when they reach maturity, while the dorsal coloration remains brownish as in the immature specimens. In this species, the green dorsal coloration is acquired gradually after maturity. Only the oldest individuals have a predominantly green dorsal coloration. The differences between the two species in the time males take to acquire the green dorsal coloration could be related to their different longevity. The coloring is acquired gradually in the most long-lived species (I. monticola). A field study was carried out on the behaviour of adult males of I. monticola during the reproductive period. The males with green dorsal coloration were seen to pair with females significantly more frequently than those with the brownish dorsal color. The increase in the green dorsal coloration (conspicuous) with the size and age of the males of this species would appear to have a clear function as an intersexual or intrasexual signal.
Species genetic ID card in animal conservation
Authors: Ruan Xiang-Dong , Wan Qiu-Hong 
Published: February 2009

Abstract
The state governments in China have laid down laws for protecting rare and endangered species, but the effective protection depends on accurate species identification. In this study, we developed one new Felidae-specific probe, pta1 probe and tested 138 skin samples from 14 species and subspecies. The results revealed that the pta1 probe succeeded in identifying all feline species in China due to species-specific “fingerprints”. As a result, we constructed a fingerprint management archives for Felidae family in China. It can provide forensic evidence of poaching for judicial organization, which have a profound effect on criminal activities of poachers, and therefore help to protect wild animals and conserve biodiversity.
Hepatic pigment cells of Proteidae (Amphibia, Urodela): A comparative histochemical and ultrastructural study
Authors: Prelovšek Petra-Maja , Mali Lilijana Bizjak , Bulog Boris 
Published: February 2009

AbstractAmphibian liver pigment cells, also known as Kupffer cells, contain various amounts of melanin, haemosiderin and lipofuscin. We used different histochemical and ultrastructural methods to analyse and compare the level of hepatic pigmentation and the structure of hepatic pigment cells in the livers of three representatives of the family Proteidae; two subspecies of the hypogean Proteus anguinus (depigmented Proteus a. anguinus and pigmented Proteus a. parkelj) and the epygean Necturus maculosus. Our analysis revealed differences at histological and ultrastructural level. While the percentage of the pigmented area and ultrastructural characteristics are similar in both subspecies of P. anguinus, great differences occur in the amount and structure of the pigment cells between P. anguinus and N. maculosus. Pigment cells are more numerous and compose larger pigmented clusters in P. anguinus. They are structurally more heterogeneous and contain a larger amount of haemosiderin when compared to N. maculosus. Our results confirm a high degree of variation in hepatic pigmentation among different amphibian species. Because many factors influence the level of hepatic pigmentation in poikilotherms, differences among species from different habitats and also among individuals of the same species are expected but are not easily explained. We propose two possible explanations for the large amount of iron present in Proteus anguinus: (1) accumulation of pigments due to the very low metabolic rate and extended lifetime; (2) large iron storage capacity as an adaptation to a low and discontinuous food supply in caves.
Academic freedom and the discovery of electroreception in catfish and dogfish
Authors: Peters Robert 
Published: February 2009

AbstractA brief sketch is given of the changing interpretation of Academic Freedom at the universities in The Netherlands during the last half of the twentieth century, by discussing the discoveries of electroreception in catfish, Ameiurus nebulosus, and dogfish, Scyliorhinus canicula. It is concluded that science is no longer hypothesis-driven, but money-driven. Whereas innovation and discoveries belong typically to the domain of the individual scientist and flourish in a bottom-up organisation, the funding agencies of today advocate a top-down approach to stimulate creativity. Apparently the resultant institutionalization has not the desired result.
Evoked bradycardia as response criterion for the detection of electrical stimuli in catfish
Authors: Peters Robert , Veeneklaas Robert , Schoenhage Albert , Eeuwes Lonneke 
Published: February 2009

Abstract
Heart rate deceleration (HRD) after exposure to novel stimuli is part of the orienting reflex, and can be used as a tool to investigate the susceptibility of various organisms to sensory stimuli. HRD as response criterion was used in unrestrained catfish, Ameiurus (Ictalurus) nebulosus (Lesueur, 1819) to investigate its susceptibility to electrical stimuli. HRD in catfish occurs after stimulation with light, mechanical stimuli, and electrical stimuli. HRD shows habituation and correlates with stimulus strength. The response to sinusoidal electrical stimuli from 70 to 700 μV/cm p-p was determined in the range from 0.1 to 1000 Hz. Using HRD as response criterion we found that at 85 μV/cm catfish react to stimuli from 0.1 to 3 Hz. In the absence of stimuli, the heart rate develops an ultradian rhythm with periods of 7 to 15 min. About twice a day cardiac arrest of 1 min occurs. During anaesthesia oscillations with a period of about 1 min are recorded. Comparison of this study with others supports the notion that there exist at least two neural channels for processing electrical stimuli. One channel is involved in predation, namely processing the fast potential changes accompanying the passage of a bioelectric dipole; another is involved in processing uniform DC fields used for navigation.
Spontaneous firing in primary afferent neurons of ampullary electroreceptor organs as attribute of bandwidth, threshold, and topology
Authors: Peters Robert , Bretschneider Franklin , Eeuwes Lonneke 
Published: February 2009

Abstract
Spontaneous firing of neurons plays an essential part in the detection of sensory stimuli. Spontaneous firing of primary afferents of ampullary electroreceptor organs in the catfish Ameiurus nebulosus (Lesueur, 1819) was studied in relation to the distribution, thresholds, and frequency characteristics of the electroreceptor organs. The spontaneous firing rate was correlated with the place on the skin. The mean inter-spike interval in 55 dorsal and 49 ventral ampullary organs in five specimens was 16.8 ms +/- 0.41 SEM and 20.5 ms +/- 0.48 SEM, corresponding to firing rates of 59.5 and 48.7 s-1 respectively. The concomitant coefficients of variation were 0.33 and 0.29. Approximately half of the dorsal ampullae were innervated by two fibres. The firing rates of each of the two fibres was lower than the firing rate of organs innervated by a single neuron. Responses to stimuli as weak as 10 pA could be recovered from the noisy average firing level provided the number of averaging sweeps was sufficiently large. This was equivalent to a stimulus of 0.025 μV/cm and was lower than the behavioural threshold of 1 μV/cm. The gain of the frequency response was enhanced at the carrier frequency, at twice the carrier frequency, and in the range from 75-90 Hz. The results revealed that the occurrence of spontaneous activity improved the signal to noise ratio of responses to electrical stimuli by reduction of the coefficient of variation, absence of a threshold, and phase locking.
Open lumina of microampullary electroreceptor organs in the transparent catfish, Kryptopterus bicirrhis (Valenciennes 1840), contain 50 mM potassium: why?
Authors: Peters Robert , Bretschneider Franklin , Eeuwes Lonneke 
Published: February 2009

Abstract
Administration of the cell impermeant fluorescent K+ and Na+ probes potassium-binding fluorescent indicator (PBFI) and sodium-binding fluorescent indicator (SBFI) to the lumina of ampullary electroreceptor organs in the transparent catfish Kryptopterus bicirrhis (Valenciennes 1840), demonstrated an unexpected high concentration of K+ ions: 50 mM. Since the lumina of the ampullary organs are in open contact with the surrounding water, such a high K+ concentration inside the lumen can be maintained only by heavy metabolic transport. The implications of this finding for stimulus transduction in freshwater ampullary electroreceptor cells are discussed.
Behavioural relevance of AC and DC in prey detection by the brown bullhead, Ameiurus nebulosus
Authors: Eeuwes Lonneke , Peters Robert , Bretschneider Franklin 
Published: February 2009

Abstract
A large range of aquatic vertebrates employs passive electroreception to detect the weak bioelectric fields that surround their prey. Bioelectric fields are dynamic in strength and frequency composition, but typically consist of a direct current (DC) and an alternating current (AC) component. We examined the biological relevance of these components for prey detection behaviour in the brown bullhead by means of a preference test. We gave each fish the choice between two small dipoles emitting a DC step or AC stimulus of variable strength, respectively. We used AC stimuli that were either representative for ventilatory movements by prey (1 Hz sine wave) or optimal for the ampullary electroreceptor cells (10 Hz sine wave). In an attempt to present a more complex stimulus, we also used slightly modified recordings of bioelectric prey fields, but this yielded no results. Brown bullheads prefer DC stimuli to 10 Hz sine waves if the stimulus intensity of either component is much larger. When the stimulus presentation consists of DC versus 1 Hz, most fish will choose randomly unless the stimulus intensities differ greatly. Then, they favour the component that had a higher amplitude during training. Our results suggest an intrinsic behavioural preference for very low frequency signals (<10 Hz) as well as plasticity in prey detection behaviour.
Energy and Enstrophy Spectra of Geostrophic Turbulent Flows Derived from a Maximum Entropy Principle
Authors: Verkley W. T. M. , Lynch Peter 
Published: February 2009

AbstractThe principle of maximum entropy is used to obtain energy and enstrophy spectra as well as average relative vorticity fields in the context of geostrophic turbulence on a rotating sphere. In the unforced-undamped (inviscid) case, the maximization of entropy is constrained by the constant energy and enstrophy of the system, leading to the familiar results of absolute statistical equilibrium. In the damped (freely decaying) and forced-damped case, the maximization of entropy is constrained by either the decay rates of energy and enstrophy or by the energy and enstrophy in combination with their decay rates. Integrations with a numerical spectral model are used to check the theoretical results for the different cases. Maximizing the entropy, constrained by the energy and enstrophy, gives a good description of the energy and enstrophy spectra in the inviscid case, in accordance with known results. In the freely decaying case, not too long after the damping has set in, good descriptions of the energy and enstrophy spectra are obtained if the entropy is maximized, constrained by the energy and enstrophy in combination with their decay rates. Maximizing the entropy, constrained by the energy and enstrophy in combination with their (zero) decay rates, gives a reasonable description of the spectra in the forced-damped case, although discrepancies remain here.
Expansion of peripheral naturally occurring T regulatory cells by Fms-like tyrosine kinase 3 ligand treatment
Authors: Swee Lee Kim , Bosco Nabil , Malissen Bernard , Ceredig Rhodri , Rolink Antonius 
Published: February 2009

AbstractFms-like tyrosine kinase 3 ligand (FLT3L) plays a major role in dendritic cell (DC) biology. Deficiency of FLT3L causes a dramatic decrease in DC numbers, whereas increasing its availability (by repetitive injections for 7-10 days) leads to a 10-fold increase in DC numbers. In this study, we show that FLT3L treatment indirectly leads to an expansion of peripheral naturally occurring T regulatory cells (NTregs). The FLT3L-induced increase in NTregs was still observed in thymectomized mice, ruling out the role of the thymus in this mechanism. Instead, the increased number of NTregs was due to proliferation of preexisting NTregs, most likely due to favored interactions with increased number of DCs. In vitro, we show that DCs induce regulatory T-cell (Treg) proliferation by direct cell contact and in an interleukin-2–dependent, T-cell receptor–independent manner. FLT3L could prevent death induced by acute graft-versus-host disease (GVHD). This study demonstrates unique aspects in the regulation of Treg homeostasis by DCs, which were unappreciated until now. It also reinforces the relevance of FLT3L treatment in GVHD by its ability to increase both the number of tolerizing DCs and NTregs.
Characterization of Cronobacter recovered from dried milk and related products
Authors: El-Sharoud Walid M , O'Brien Stephen , Negredo Carmen , Iversen Carol , Fanning Séamus , Healy Brendan 
Published: February 2009

Abstract

Background

Cronobacter is a recently proposed genus consisting of six genomospecies that encompass the organisms previously identified as Enterobacter sakazakii. Cronobacter are opportunistic pathogens and are known to cause serious infections in infants, particularly neonates. High case fatality rates have been associated with infections and acute sequelae can occur in survivors with severe ramifications on neurological development. Infant formula has been identified as one route of transmission for infection in infants. However, the primary reservoirs for subsequent contamination of foods with Cronobacter remain undefined due to the ubiquitous nature of these organisms. More recently, infections in adults have been reported, especially amongst the elderly and patients who are immunocompromised. To help prevent the transmission of infection, it is important to identify the main food sources for Cronobacter. The aim of this study was to identify and characterize Cronobacter isolated from dried-milk and related products available in an Egyptian food market.

Results
In total sixteen Cronobacter strains were isolated from 152 dairy-based products. These were identified and characterized using pheno- and genotyping experiments. Real-time PCR confirmed the detection of Cronobacter. Following antibiotic susceptibility tests, 3 strains showed resistance to trimethoprim and/or neomycin. Phenotype profiles were generated based on key biochemical distinguishing tests. Pulsed-field gel electrophoresis (PFGE) identified 8 PFGE types amongst the collection of strains. Repetitive sequence based PCR (rep-PCR) analysis identified 3 rep-PCR types amongst the collection of strains. Sequencing of the recN gene was used to differentiate among the recently described species of Cronobacter.

Conclusion
This study identified the presence of Cronobacter in dried milk and related products sourced from the Nile-Delta region of Egypt. Although the majority of the strains were susceptible to the antibiotics tested, resistance was observed in three isolates, highlighting the risks associated with Cronobacter contamination in foods. Phenotype and genotype analysis should be applied to further characterize Cronobacter spp. and prevent its transmission into food products.
DNA instability in replicating Huntington's disease lymphoblasts
Authors: Cannella Milena , Maglione Vittorio , Martino Tiziana , Ragona Giuseppe , Frati Luigi , Li Guo-Min , Squitieri Ferdinando 
Published: February 2009

Abstract

Background
The expanded CAG repeat in the Huntington's disease (HD) gene may display tissue-specific variability (e.g. triplet mosaicism) in repeat length, the longest mutations involving mitotic (germ and glial cells) and postmitotic (neurons) cells. What contributes to the triplet mutability underlying the development of HD nevertheless remains unknown. We investigated whether, besides the increased DNA instability documented in postmitotic neurons, possible environmental and genetic mechanisms, related to cell replication, may concur to determine CAG repeat mutability. To test this hypothesis we used, as a model, cultured HD patients' lymphoblasts with various CAG repeat lengths.

Results
Although most lymphoblastoid cell lines (88%) showed little or no repeat instability even after six or more months culture, in lymphoblasts with large expansion repeats beyond 60 CAG repeats the mutation size and triplet mosaicism always increased during replication, implying that the repeat mutability for highly expanded mutations may quantitatively depend on the triplet expansion size. None of the investigated genetic factors, potentially acting in cis to the mutation, significantly influence the repeat changes. Finally, in our experiments certain drugs controlled triplet expansion in two prone-to-expand HD cell lines carrying large CAG mutations.

Conclusion
Our data support quantitative evidence that the inherited CAG length of expanded alleles has a major influence on somatic repeat variation. The longest triplet expansions show wide somatic variations and may offer a mechanistic model to study triplet drug-controlled instability and genetic factors influencing it.