bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adenosinergic and cholinergic control mechanisms during hypoxia in the epaulette shark (Hemiscyllium ocellatum), with emphasis on branchial circulation
Authors: Stensløkken Kåre-Olav , Sundin Lena , Renshaw Gillian M. C. , Nilsson Göran E. 
Published: November 2004

SUMMARYCoral reef platforms may become hypoxic at night during low tide. One animal in that habitat, the epaulette shark (Hemiscyllium ocellatum),survives hours of severe hypoxia and at least one hour of anoxia. Here, we examine the branchial effects of severe hypoxia (&lt;0.3 mg oxygen l–1 for 20 min in anaesthetized epaulette shark), by measuring ventral and dorsal aortic blood pressure (PVAand PDA), heart rate (fh), and observing gill microcirculation using epi-illumination microscopy. Hypoxia induced a flow of blood in two parallel blood vessels, termed longitudinal vessels, in the outer borders of the free tip of the gill filament. Hypoxia also induced significant falls in fh, PVA and PDA, and a biphasic change in ventilation frequency (increase followed by decrease). Adenosine injection (1μmol kg–1) also initiated blood flow in the longitudinal vessels, in addition to significant drops in PVA, PDA and fh, and a biphasic response in ventilation frequency (decrease followed by increase) indicating that adenosine influences ventilation. Aminophylline (10 mg kg–1),an A1 and A2 adenosine receptor antagonist, blocked the effects of adenosine injection, and also significantly reduced blood flow in the longitudinal vessels during hypoxia. In the second part of the study, we examined the cholinergic influence on the cardiovascular circulation during severe hypoxia (&lt;0.3 mg l–1) using antagonists against muscarinic (atropine 2 mg kg–1) and nicotinic (tubocurarine 5 mg kg–1) receptors. Injection of acetylcholine (ACh; 1μmol kg–1) into the ventral aorta caused a marked fall in fh, a large increase in PVA, but small changes in PDA (suggesting increased Rgill). Atropine was able to inhibit the branchial vascular responses to ACh but not the hypoxic bradycardia, suggesting the presence of muscarinic receptors on the heart and gill vasculature, and that the hypoxia induced bradycardia is of non-cholinergic origin. The results suggest that adenosine mediates increases in the arterio–venous circulation in the gill during hypoxia. This may serve to increase blood supply to heart and gill tissue.
Bacterial lipopolysaccharide (LPS) modulates corticotropin-releasing hormone (CRH) content and release in the brain of juvenile and adult tilapia (Oreochromis mossambicus; Teleostei)
Authors: Pepels P. P. L. M. , Bonga S. E. Wendelaar , Balm P. H. M. 
Published: November 2004

SUMMARYAlthough immune endocrine interactions in teleost fish have been shown to involve adrenocorticotropin hormone (ACTH) and cortisol, the involvement of corticotropin-releasing hormone (CRH) has not been demonstrated. The present study investigates whether treatment with bacterial endotoxin(lipopolysaccharide, LPS) modulates brain CRH contents or in vitroCRH release in tilapia (Oreochromis mossambicus). 10 days LPS(Escherichia coli) exposure of juvenile tilapia (4.5 weeks post hatch) via the ambient water increased brain CRH and α-MSH content,whereas cortisol contents were not increased. This indicates that the elevation of brain CRH levels were not secondary to activation of HPI-axis. Adult tilapia were treated for 6 days with LPS (intraperitoneally) and were sampled before and after 24 h of confinement. Overall LPS pre-treatment modified the reaction of tilapia to the additional stressor of 24 h confinement, as interactions between LPS treatment and confinement were observed at the level of the hypothalamus (diencephalic CRH content), the pituitary (CRH and α-MSH content) and in plasma glucose levels. In vitro, LPS pre-treatment abolished CRH release from telencephalic tissues induced by norepinephrine, one of the CRH secretagogues released during stress in vivo. This effect might be a mechanism of action through which LPS in vivo abolished the up-regulation of telencephalic CRH induced by confinement stress. Our results provide evidence that the role of CRH in immune–endocrine interactions is a phylogenetically old mechanism, and we here demonstrate that LPS molecules are able to locally modulate CRH release in the central nervous system.
Crater landscape: two-dimensional oxygen gradients in the circulatory system of the microcrustaceanDaphnia magna
Authors: Pirow R. , Bäumer C. , Paul R. J. 
Published: November 2004

SUMMARYOxygen transport processes in millimetre-sized animals can be very complex,because oxygen molecules do not exclusively follow the pathway predetermined by the circulating fluid but may also simultaneously move from the respiratory surfaces to the tissues along different paths by diffusion. The present study made use of the oxygen-sensitive phosphorescence probe Oxyphor R2 to analyze the internal oxygen pathway in the transparent microcrustacean Daphnia magna. Oxyphor R2 was injected into the circulatory system and the distribution of oxygen partial pressure (PO2)in the haemolymph was measured by phosphorescence lifetime imaging in the PO2 range 0–6 kPa (0–30% air saturation). There were substantial differences in the shape of the two-dimensional PO2 profiles depending on the concentration of haemoglobin (Hb) in the haemolymph. A steep global gradient,from posterior to anterior, occurred in animals with low concentrations of Hb(90–167 μmol l–1 haem). In contrast, animals with a five- to sixfold higher concentration of Hb showed flat internal PO2 gradients which, however, were only present under reduced ambient oxygen tensions(PO2amb=3–1 kPa), when Hb was maximally involved in oxygen transport. Under these conditions, the presence of Hb at high concentrations stabilized the unloading PO2 in the central body to 0.9–0.4 kPa. Independent of Hb concentration and body size, the loading PO2 was always 0.5 kPa below the PO2amb. From these PO2 profiles, it was possible (i) to follow the track of oxygen within the animal, and (ii) to visualize the shift from a diffusion-dominated to a convection-dominated transport as a result of increased Hb concentration.
Partial link between the seasonal acquisition of cold-tolerance and desiccation resistance in the goldenrod gall flyEurosta solidaginis(Diptera: Tephritidae)
Authors: Williams Jason B. , Ruehl Naomi C. , Lee Richard E. 
Published: November 2004

SUMMARYPossible links between seasonal increases in cold-tolerance and desiccation resistance were examined in field-collected larvae of the goldenrod gall fly, Eurosta solidaginis. From 20 September to 30 October 2001, larvae exhibited a gradual increase in cold-tolerance culminating in 100% survival of freezing at –20°C for 24 h. The increase in cold-tolerance was probably due to a concomitant increase in cryoprotectants as measured by hemolymph osmolality (488–695 mOsmol kg–1). In contrast to the gradual increase in cold-tolerance, larvae exhibited two distinct phases of reduced rates of water loss. The first phase was an abrupt sixfold decrease to 0.57 μg mm–2 h–1 between 3 and 16 October. The first phase of reduced rates of water loss was not correlated with changes in cold-tolerance; nor was it correlated with hemolymph osmolality and body water content, which remained constant throughout the study. The reduction in rates of water loss during the first phase were probably the result of decreased respiratory water loss as the larvae entered diapause, and possibly reduced cuticular water loss as larvae increased the amount of their cuticular hydrocarbons. Interestingly, the first phase of reduced water loss was associated with, and may have been cued by, a reduction in the water potential of the gall tissues surrounding the larvae. The second phase was a more subtle fourfold reduction in rates of water loss occurring between 16 October and 11 December. In contrast to the first phase,the second phase of increased desiccation resistance correlated closely with increases in hemolymph osmolality (568–870 mOsmol kg–1). The correlation between seasonal increases in hemolymph osmolality and reduction in rates of water loss may represent a link between desiccation resistance and cold-tolerance in this species.
Serum S-100B as an Indicator of Early Postoperative Deterioration after Meningioma Surgery
Authors: Stranjalis George , Korfias Stefanos , Psachoulia Christina , Boviatsis Efstathios , Kouyialis Andreas , Protopappa Despina , Sakas Damianos E 
Published: November 2004

AbstractBackground: S-100B protein is an established serum marker of primary and secondary brain damage in head injury and stroke. Despite major progress in neurophysiologic monitoring, there are still difficulties in the early identification and quantification of evolving edema or trauma after craniotomy for tumor. In this study we aimed to correlate serum S-100B values with early postoperative neurologic course as well as late outcome in meningioma surgery.Methods: We enrolled 50 consecutive patients who underwent meningioma resection. Serum S-100B was measured preoperatively and postcraniotomy for 7 consecutive days. Twenty-five patients (50%) developed immediate postoperative neurologic deterioration, and 15 (30%) had unfavorable 6-month outcomes. We used the Mann–Whitney U-test to assess the association of S-100B with all variables of interest. We used multiple logistic regression to search for the most significant predictor of postoperative deterioration.Results: Increased S-100B was highly correlated with larger tumors, intraoperative difficulties, postcraniotomy acute deterioration, and long-term poor outcome. In addition, multiple logistic regression showed that age, sex, site, preoperative edema, history of meningioma resection, extent of resection, and histologic type did not correlate with postoperative increases in S-100B. Furthermore, patients with postoperative S-100B values &gt;0.4 μg/L had increased risk of deterioration (relative risk = 9.0; 95% confidence interval, 2.4–34; P &lt;0.0001) and of poor ultimate outcome (relative risk = 11; 95% confidence interval, 1.6–77; P = 0.002).Conclusions: After meningioma excision, postcraniotomy increases in serum S-100B appear to be an early indicator of short-term postoperative neurologic deterioration and of a poor longer-term outcome.
Increased Plasma Lipid-Poor Apolipoprotein A-I in Patients with Coronary Artery Disease
Authors: Suzuki Makiko , Wada Hisayasu , Maeda Satoshi , Saito Kuniaki , Minatoguchi Shinya , Saito Kazunori , Seishima Mitsuru 
Published: November 2004

AbstractBackground: Pre-β1-HDL participates in a cyclic process involved in the retrieval of cholesterol from peripheral tissues. Although pre-β1-HDL can be measured by two-dimensional electrophoresis or crossed immunoelectrophoresis, these methods are time-consuming and require technical expertise. In this study, we separated plasma lipid-poor apolipoprotein A-I (apo A-I) by high-performance size-exclusion chromatography.Methods: We measured plasma lipid-poor apo A-I in 20 male patients with coronary artery disease [CAD; mean (SD) age, 64.0 (18) years] and 15 male controls [54.7 (17) years] and in 7 female CAD patients [70.3 (7.7) years] and 9 female controls [65.1 (4.7) years].Results: Lipid-poor apo A-I was most stable when stored at −80 °C in the presence of aprotinin (final concentration, 50 kIU/L). The lipid-poor apo A-I concentration decreased during incubation at 37 °C, and this was not prevented by the addition of 2 mmol/L of the lecithin:cholesterol acyltransferase (LCAT) inhibitor 5,5′-dithiobis(2-nitrobenzoic acid). Lipid-poor apo A-I was significantly higher in CAD patients than in controls [38.3 (7.9) mg/L for male CAD patients vs 29.3 (7.3) mg/L for male controls; 43.3 (11) mg/L for female CAD patients vs 27.1 (7.4) mg/L for female controls (P &lt;0.01 for both)]. There were no significant differences in LCAT activity or cholesteryl ester transfer protein (CETP) concentration between patients and controls. Moreover, the plasma lipid-poor apo A-I concentration was not significantly correlated with LCAT or CETP activities.Conclusions: Although the production of lipid-poor apo A-I in plasma is not fully understood, our results indicate that lipid-poor apo A-I could be used as a marker for arteriosclerosis and demonstrate that it is not identical to the pre-β1-HDL measured by other methods.
Activation of the kallikrein-kinin system and release of new kinins through alternative cleavage of kininogens by microbial and human cell proteinases
Authors: Imamura Takahisa , Potempa Jan , Travis James 
Published: November 2004

AbstractKinins are released from kininogens through the activation of the Hageman factor-prekallikrein system or by tissue kallikrein. These peptides exert various biological activities, such as vascular permeability increase, smooth muscle contraction, pain sensation and induction of hypotension. In many instances kinins are thought to be involved in the pathophysiology of various diseases. Recent studies have revealed that microbial and human cell proteinases activate Hageman factor and/or prekallikrein, or directly release kinin from kininogens. This review discusses the activation of the kinin-release system by mast-cell tryptase and microbial proteinases, including gingipains, which are cysteine proteinases fromPorphyromonas gingivalis, the major pathogen of periodontal disease. Each enzyme is evaluated in the context of its association to allergy and infectious diseases, respectively. Furthermore, a novel system of kinin generation directly from kininogens by the concerted action of two proteinases is described. An interesting example of this system with implications to bacterial pathogenicity is the release of kinins from kininogens by neutrophil elastase and a synergistic action of cysteine proteinases fromStaphylococcus aureus. This alternative production of kinins by proteinases present in diseased sites indicates a significant contribution of proteinases other than kallikreins in kinin generation. Therefore kinin receptor antagonists and proteinase inhibitors may be useful as therapeutic agents.
Fine Art Examination and Conservation
Authors: Berrie Barbara H. 
Published: November 2004

AbstractScience and connoisseurship come together in the examination and conservation of fine art. Chemical and physical analysis methods are used to examine art objects for a variety of purposes including the establishment of authenticity, schloarly investigation of the works, and evaluation of their state of preservation. Methods for analyzing the works are described and conservation scientists’ efforts in the field of preservation are discussed. Knowledge of the materials used for the creation of a work of art is invaluable for understanding how it was made, and how best to preserve it. Choosing appropriate treatments for a work of art requires knowledge of its chemical components and their deterioration mechanisms as well as how the artist applied them. Current research on the stablity of materials that have been used by artists and artists’ techniques is summarized. Examples of the application of scientific analysis of the investigation of artists’ working methods and the original appearance of works are given.
A disorder resembling pseudoachondroplasia but without COMP mutation
Authors: Spranger J.W. , Zabel B. , Kennedy J. , Jackson G. , Briggs M. 
Published: November 2004

AbstractPseudoachondroplasia (PA) is an autosomal dominant skeletal dysplasia characterized by disproportionate short stature, generalized ligamentous laxity, irregular epi‐metaphyseal ossification, and vertebral anomalies that regress with age. It usually manifests in the second year of life or later. The clinically and radiographically variable disorder is caused by mutations in the COMP gene. Parental gonadal mosaicism may lead to recurrence of the disorder in children of unaffected parents. Here, we describe sibs with bone changes similar to those seen in very severe PA born to clinically and radiographically unaffected parents. Sequencing of all 19 exons of the COMP gene failed to disclose a mutation. The sibs appear to be affected by a disorder resembling PA but resulting from a defect of an extracellular matrix protein other than COMP. It may be suspected in patients with unusually severe dwarfism, severe epi‐metaphyseal abnormalities, and persistent platyspondyly. © 2004 Wiley‐Liss, Inc.
Novel case of dup(3q) syndrome due to a de novo interstitial duplication 3q24‐q26.31 with minimal overlap to the dup(3q) critical region
Authors: Meins Moritz , Hagh Javad Karimzad , Gerresheim Fritz , Einhoff Elisabeth , Olschewski Heidi , Strehl Henning , Epplen Jörg T. 
Published: November 2004

AbstractDup(3q) syndrome is characterized by typical facial features, mental and growth retardation, often with congenital heart defects. The syndrome has attracted special attention because of the clinical overlap with Cornelia de Lange syndrome (CDLS). Patients with dup(3q) syndrome are trisomic for segments of the long arm of chromosome 3, most often within the region 3q21 to 3qter. Most cases have arisen as unbalanced translocations and do involve other chromosomes also. A dup(3q) minimal region has been defined at 3q26.3‐q27. We report here a 15‐month‐old boy with a de novo interstitial inverted duplication of 3q24‐q26.31. Clinical evaluation revealed mild but typical features of dup(3q) syndrome. The duplication was characterized by conventional and molecular cytogenetics. The results allow further narrowing of the dup(3q) critical region at its distal end and suggest the existence of one or several major genes responsible for the dup(3q) syndrome in the proximal half of 3q26.31. Moreover, the results of fluorescence in situ hybridization (FISH) analysis with BAC probes suggest a disruption of the NLGN1 gene at the distal end of the duplication in 3q26.31 in the patient. The breakpoint within NLGN1 is unique for this patient, and the contribution of NLGN1 disruption to the phenotype of this patient remains unclear. Yet since NLGN1 is involved in synaptogenesis in the central nervous system, altered gene dosage is a good candidate for mental retardation as a recurrent feature of dup(3q) syndrome. © 2004 Wiley‐Liss, Inc.
A novel mutation (E767K) in the second extracellular loop of the calcium sensing receptor in a family with autosomal dominant hypocalcemia
Authors: Uçkun‐Kitapçi Ayşin , Underwood Louis E. , Zhang Jihui , Moats‐Staats Billie 
Published: November 2004

AbstractAutosomal dominant hypocalcemia resulting from gain‐of‐function mutations of the calcium sensing receptor (CASR) is a rare familial disorder that can become evident at any age. We report a novel mutation (E767K) of the CASR in a family with autosomal dominant hypocalcemia. Ten members of the family had a history of hypocalcemia. The index case exhibited marked hypocalcemia and seizures in the newborn period, while her father who also has hypocalcemia, was largely asymptomatic except for a myocardial infarction‐like event at 21 years of age, a new presentation of the disorder. The E767K mutation, which resides in the second extracellular loop adjacent to the fifth transmembrane domain, co‐segregated with hypocalcemia in these two individuals. Both subjects are heterozygous for the mutation. The proband is also heterozygous for the previously reported CASR polymorphism of G990R in the intracellular domain, while her father is homozygous. The co‐segregation of this naturally occurring mutation with autosomal dominant hypocalcemia supports the previously reported experimental model in which it was proposed that the three acidic residues (767, 758, and 759) in exo‐loop 2 in CASR help maintain an inactive conformation of the receptor. © 2004 Wiley‐Liss, Inc.
Recurrent adjacent‐2 segregation of a familial t(14;21)(q11.2;q11.2): Phenotypic comparison of two brothers and a paternal aunt inheriting the der(14)
Authors: Chen Emily , Choe Michele A. , Loughman William D. , Covert Susan , Bitts Sheila , Rowe Amy , Beischel Linda , Johnson John P. 
Published: November 2004

AbstractA 14‐year‐old boy was referred for a genetics evaluation after high‐resolution chromosome analysis showed a small amount of extra material in the proximal long arm of chromosome 21. Five years prior, his karyotype analysis was interpreted as normal with a variant chromosome 21. The patient has short palpebral fissures, strabismus, flat antihelices of the ears, long thumbs with bilaterally absent interphalangeal creases, proximal bilateral 3/4 syndactyly, small testes, hypotonia, mental retardation, and speech problems. He has significant depression and behavioral problems including hyperactivity, aggression, and impulsivity. His 8‐year‐old brother has more severe behavioral disturbances and depression, but less significant mental retardation. A paternal aunt has mental retardation, is unusually docile, and appears similar to our patient. Chromosome analysis and fluorescence in situ hybridization (FISH) whole chromosome paint of chromosome 21 showed that the patient's father carries a “cryptic” balanced translocation, 46,XY, t(14;21)(q11.2;q11.2), as does the patient's paternal grandmother. Uniparental disomy studies using seven informative polymorphic nucleotide repeat markers from 14q and 21q confirmed biparental inheritance of the number 14 and 21 chromosomes for each brother, and indicate that they and the paternal aunt, all of whom inherited the der(14), are monosomic for proximal 21q and trisomic for proximal 14q. These karyotypes arose through an adjacent‐2 segregation in the father on two occasions, and from the paternal grandmother on one occasion. This family is an example of recurrent malsegregation with translocations involving the acrocentrics. © 2004 Wiley‐Liss, Inc.
A Two‐Compartment Fluidized Bed Reactor for CO2 Capture by Chemical‐Looping Combustion
Authors: Kronberger B. , Johansson E. , Löffler G. , Mattisson T. , Lyngfelt A. , Hofbauer H. 
Published: November 2004

AbstractChemical‐looping combustion (CLC) is a combustion method for a gaseous fuel with inherent separation of the greenhouse gas carbon dioxide. A CLC system consists of two reactors, an air reactor and a fuel reactor, and an oxygen carrier circulating between the two reactors. The oxygen carrier transfers the oxygen from the air to the fuel. The flue gas from the fuel reactor consists of carbon dioxide and water, while the flue gas from the air reactor is nitrogen from the air. A two‐compartment fluidized bed CLC system was designed and tested using a flow model in order to find critical design parameters. Gas velocities and slot design were varied, and the solids circulation rate and gas leakage between the reactors were measured. The solids circulation rate was found to be sufficient. The gas leakage was somewhat high but could be reduced by altering the slot design. Finally, a hot laboratory CLC system is presented with an advanced design for the slot and also with the possibility for inert gas addition into the downcomer for solids flow increase.
Magnetic Field‐induced Increasing of the Reaction Rates Controlled by the Diffusion of Paramagnetic Gases
Authors: Peng Z. , Wang J. , Huang Y. , Chen Q. 
Published: November 2004

AbstractThe rates of some reactions are greatly limited by diffusion rates of paramagnetic gases. The idea to enhance them by means of applying a magnetic field was considered and tested in this paper. The introduction of a weak magnetic field into the oxidation reaction of aqueous suspensions of ferrous hydroxide increased the reaction rate to a considerable extent, which was attributed to magnetically induced convection for the existence of a gradient of susceptibilities and magnetic strength. The idea can be valuable in all the processes, in which diffusion rates of the paramagnetic gases control the reaction rates or at least play an important role.