bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preliminary characterization and biological reduction of putative biogenic iron oxides (BIOS) from the Tonga‐Kermadec Arc, southwest Pacific Ocean
Authors: LANGLEY S. , IGRIC P. , TAKAHASHI Y. , SAKAI Y. , FORTIN D. , HANNINGTON M. D. , SCHWARZ‐SCHAMPERA U. 
Published: December 2008

ABSTRACTSediment samples were obtained from areas of diffuse hydrothermal venting along the seabed in the Tonga sector of the Tonga‐Kermadec Arc, southwest Pacific Ocean. Sediments from Volcano 1 and Volcano 19 were analyzed by X‐ray diffraction (XRD) and found to be composed primarily of the iron oxyhydroxide mineral, two‐line ferrihydrite. XRD also suggested the possible presence of minor amounts of more ordered iron (hydr)oxides (including six‐line ferrihydrite, goethite/lepidocrocite and magnetite) in the biogenic iron oxides (BIOS) from Volcano 1; however, Mössbauer spectroscopy failed to detect any mineral phases more crystalline than two‐line ferrihydrite. The minerals were precipitated on the surfaces of abundant filamentous microbial structures. Morphologically, some of these structures were similar in appearance to the known iron‐oxidizing genus Mariprofundus spp., suggesting that the sediments are composed of biogenic iron oxides. At Volcano 19, an areally extensive, active vent field, the microbial cells appeared to be responsible for the formation of cohesive chimney‐like structures of iron oxyhydroxide, 2–3 m in height, whereas at Volcano 1, an older vent field, no chimney‐like structures were apparent. Iron reduction of the sediment material (i.e. BIOS) by Shewanella putrefaciens CN32 was measured, in vitro, as the ratio of [total Fe(II)]:[total Fe]. From this parameter, reduction rates were calculated for Volcano 1 BIOS (0.0521 day−1), Volcano 19 BIOS (0.0473 day−1), and hydrous ferric oxide, a synthetic two‐line ferrihydrite (0.0224 day−1). Sediments from both BIOS sites were more easily reduced than synthetic ferrihydrite, which suggests that the decrease in effective surface area of the minerals within the sediments (due to the presence of the organic component) does not inhibit subsequent microbial reduction. These results indicate that natural, marine BIOS are easily reduced in the presence of dissimilatory iron‐reducing bacteria, and that the use of common synthetic iron minerals to model their reduction may lead to a significant underestimation of their biological reactivity.
Biomineralization by photosynthetic organisms: Evidence of coevolution of the organisms and their environment?
Authors: RAVEN J. A. , GIORDANO M. 
Published: December 2008

ABSTRACTBiomineralization is widespread among photosynthetic organisms in the ocean, in inland waters and on land. The most quantitatively important biogeochemical role of land plants today in biomineralization is silica deposition in vascular plants, especially grasses. Terrestrial plants also increase the rate of weathering, providing the soluble substrates for biomineralization on land and in water bodies, a role that has had global biogeochemical impacts since the Devonian. The dominant photosynthetic biomineralizers in today's ocean are diatoms and radiolarians depositing silica and coccolithophores and foraminifera depositing calcium carbonate. Abiotic precipitation of silica from supersaturated seawater in the Precambrian preceded intracellular silicification dominated by sponges, then radiolarians and finally diatoms, with successive declines in the silicic acid concentration in the surface ocean, resulting in some decreases in the extent of silicification and, probably, increases in the silicic acid affinity of the active influx mechanisms. Calcium and bicarbonate concentrations in the surface ocean have generally been supersaturating with respect to the three common calcium carbonate biominerals through geological time, allowing external calcification as well as calcification in compartments within cells or organisms. The forms of calcium carbonate in biominerals, and presumably the evolution of the organisms that produce them, have been influenced by abiotic variations in calcium and magnesium concentrations in seawater, and calcium carbonate deposition has probably also been influenced by carbon dioxide concentration whose variations are in part biologically determined. Overall, there has been less biological feedback on the availability of substrates for calcification than is the case for silicification.
Redox control of N:P ratios in aquatic ecosystems
Authors: QUAN T. M. , FALKOWSKI P. G. 
Published: December 2008

ABSTRACTThe ratio of dissolved fixed inorganic nitrogen to soluble inorganic phosphate (N:P) in the ocean interior is relatively constant, averaging ~16 : 1 by atoms. In contrast, the ratio of these two elements spans more than six orders of magnitude in lakes and other aquatic environments. To understand the factors influencing N:P ratios in aquatic environments, we analyzed 111 observational datasets derived from 35 water bodies, ranging from small lakes to ocean basins. Our results reveal that N:P ratios are highly correlated with the concentration of dissolved O2 below ~100 µmol L−1. At higher concentrations of O2, N:P ratios are highly variable and not correlated with O2; however, the coefficient of variation in N:P ratios is strongly related to the size of the water body. Hence, classical Redfield ratios observed in the ocean are anomalous; this specific elemental stoichiometry emerges not only as a consequence of the elemental ratio of the sinking flux of organic matter, but also as a result of the size of the basins and their ventilation. We propose that the link between N:P ratios, basin size and oxygen levels, along with the previously determined relationship between sedimentary δ15N and oxygen, can be used to infer historical N:P ratios for any water body.
Spatiotemporal distribution of microbial communities in a coastal, sandy aquifer system (Doñana, SW Spain)
Authors: VELASCO AYUSO S. , GUERRERO M. C. , MONTES C. , LÓPEZ‐ARCHILLA A. I. 
Published: December 2008

ABSTRACTThe aquifer system of Doñana (SW Spain) represents the most important freshwater source in the Doñana Natural Area. Its spatiotemporal dynamics favours the hydrological connection between surface and subsurface ecosystems, and promotes matter fluxes among the different terrestrial and aquatic systems present here. This aquifer has been intensively studied from a hydrogeological point of view but little is known from an ecological perspective. In order to understand the ecological roles played by microbial communities in this system, we conducted a long‐term seasonal study of bacterial abundance, cell biomass, bacterial biomass and functional activities over a 2‐year period. Bacterial abundance ranged between 2.11 ± 1.79 × 105 and 8.58 ± 6.99 × 107 bacteria mL−1 groundwater, average cell biomass was estimated to be 77.01 ± 31.56 fgC and bacterial biomass varied between 8.99 ± 4.10 × 10−2 and 5.65 ± 0.70 µgC mL−1. Iron‐related bacteria showed the highest activities among the functional groups studied. Moreover, among the variables that usually control spatial distributions of microbial communities in aquifer systems, depth did not have a relevant effect on this aquifer, at least in the range of depths studied, but grain size, probably due to its direct effects on hydrogeological parameters, such as permeability or porosity, appeared to exert moderate control, principally in terms of bacterial abundance. Finally, significant seasonal differences in the means of these microbiological variables were also observed; temperature seems to be the main factor controlling the temporal distribution of microbial communities in this aquifer system.
B‐Lymphocyte stimulator: a new biomarker for multiple myeloma
Authors: Jiang Pu , Yueguo Wang , Huiming Huang , Hongxiang Yuan , Mei Wang , Ju Shaoqing 
Published: December 2008

AbstractMultiple myeloma (MM) is a common malignant tumor, characterized by unlimited proliferation of abnormal plasmocytes in bone marrow. Considering the biological function of B‐Lymphocyte stimulator (BLyS) and its receptors in B cell, we examined BLyS and its receptors expression in MM cells. Our studies confirmed that BLyS and its receptors are expressed in MM cells, including KM3, CZ‐1, and primary MM cells, playing an important role in the survival and proliferation of MM cells. Additionally, we provide evidence that BLyS protein is located in the MM cell plasma membrane. We also found that IFN‐γ and IL‐6 can induce BLyS expression on MM cells, while after the treatment of BAY11‐7082, an IkB‐α phosphorylation inhibitor, IFN‐γ induced up regulation of BLyS was completely inhibited, suggesting that nuclear factor κB (NF‐κB) might be involved in the mechanism of the regulation of BLyS levels in response to cytokines. Finally, linear correlation analysis of the Lactate Dehydrogenase concentration and beta 2‐microglobulin level with BLyS, and expressions of BLyS mRNA in MM patients revealed a significant correlation between them (P < 0.01 in all case), showing that BLyS could be a biomarker for the diagnosis and treatment of MM.
Reduction in labile plasma iron during treatment with deferasirox, a once‐daily oral iron chelator, in heavily iron‐overloaded patients with β‐thalassaemia
Authors: Daar Shahina , Pathare Anil , Nick Hanspeter , Kriemler‐Krahn Ulrike , Hmissi Abdel , Habr Dany , Taher Ali 
Published: December 2008

AbstractThis subgroup analysis evaluated the effect of once‐daily oral deferasirox on labile plasma iron (LPI) levels in patients from the prospective, 1‐yr, multicentre ESCALATOR study. Mean baseline liver iron concentration and median serum ferritin levels were 28.6 ± 10.3 mg Fe/g dry weight and 6334 ng/mL respectively, indicating high iron burden despite prior chelation therapy. Baseline LPI levels (0.98 ± 0.82 μmol/L) decreased significantly to 0.12 ± 0.16 μmol/L, 2 h after first deferasirox dose (P = 0.0006). Reductions from pre‐ to post‐deferasirox administration were also observed at all other time points. Compared to baseline, there was a significant reduction in preadministration LPI that reached the normal range at week 4 and throughout the remainder of the study (P ≤ 0.02). Pharmacokinetic analysis demonstrated an inverse relationship between preadministration LPI levels and trough deferasirox plasma concentrations. Once‐daily dosing with deferasirox ≥20 mg/kg/d provided sustained reduction in LPI levels in these heavily iron‐overloaded patients, suggesting 24‐h protection from LPI. Deferasirox may therefore reduce unregulated tissue iron loading and prevent further end‐organ damage.
Sudden infant death syndrome (SIDS) in African Americans: polymorphisms in the gene encoding the stress peptide pituitary adenylate cyclase‐activating polypeptide (PACAP)
Authors: Cummings Kevin J , Klotz Cherise , Liu Wei‐Qiao , Weese‐Mayer Debra E , Marazita Mary L , Cooper Margaret E , Berry‐Kravis Elizabeth M , Tobias Rose , Goldie Cameron , Bech‐Hansen N Torben , Wilson Richard JA 
Published: December 2008

AbstractAims: Mice lacking pituitary adenylate cyclase‐activating polypeptide (PACAP) are prone to sudden death in the second post‐natal week, having respiratory and metabolic disturbances reminiscent of the human Sudden Infant Death Syndrome (SIDS). Here we test the hypothesis that the human PACAP gene is a site of genetic variance associated with SIDS in a cohort of 92 victims and 92 matched controls.Methods: Using polymerase chain reaction and sequencing, we examined the PACAP gene in 92 SIDS cases (46 Caucasians and 46 African Americans) and 92 race‐ and gender‐matched controls.Results: We found no significant associations between PACAP and SIDS in Caucasians. However, in the African Americans, a non‐synonymous single nucleotide polymorphism (i.e. an aspartic acid/glycine coding variant, rs2856966) within exon 2 of PACAP was significantly associated with SIDS (p = 0.004), as were haplotypes containing this polymorphism (p < 0.0001). Glycine was three times more likely at this location in the African‐American SIDS victims (17 cases) than African‐American controls (5 cases).Conclusion: These data are the first to suggest an association between a variant within the coding region of the PACAP gene and SIDS. Based on these findings, further investigations are warranted into the functional importance of PACAP signaling in neonatal survival and the role of PACAP‐signaling abnormalities in SIDS.
Abnormal growth in mitochondrial disease
Authors: Wolny S , McFarland R , Chinnery P , Cheetham T 
Published: December 2008

AbstractAim: To review the height and weight of children with mitochondrial disease attending our supra‐regional service.Methods: This was a retrospective audit of cross‐sectional data. Height and weight measurements were available in 24 children and adolescents (median 7.86 years; range 1.76–20.5 years) who all had a confirmed diagnosis of mitochondrial disease. Values were converted to SD scores using UK reference data.Results: Patients with mitochondrial disease were short with an overall SD score of −1.97 (95% confidence intervals −2.72 to –1.23 SD). Patients were also thin with a relatively low BMI SDS of −1.07 (95% confidence intervals −1.69 to ‐ 0.07 SD), which fell with advancing years (r =−0.7; p < 0.000).Conclusion: Short stature and a progressive reduction in body mass index (BMI) are features of mitochondrial disease in childhood. The mechanisms underlying the abnormal growth in these patients need to be studied in more detail.
A severe form of Noonan syndrome and autosomal dominant café‐au‐lait spots – evidence for different genetic origins
Authors: Nyström Anna‐Maja , Ekvall Sara , Strömberg Bo , Holmström Gerd , Thuresson Ann‐Charlotte , Annerén Göran , Bondeson Marie‐Louise 
Published: December 2008

AbstractAim: The clinical overlap among Noonan syndrome (NS), cardio‐facio‐cutaneous (CFC), LEOPARD and Costello syndromes as well as Neurofibromatosis type 1 is extensive, which complicates the process of diagnosis. Further genotype–phenotype correlations are required to facilitate future diagnosis of these patients. Therefore, investigations of the genetic cause of a severe phenotype in a patient with NS and the presence of multiple café‐au‐lait spots (CAL) spots in the patient and four members of the family were performed.Methods: Mutation analyses of candidate genes, PTPN11, NF1, SPRED1 and SPRED2, associated with these syndromes, were conducted using DNA sequencing.Results: A previously identified de novo mutation, PTPN11 F285L and an inherited NF1 R1809C substitution in the index patient were found. However, neither PTPN11 F285L, NF1 R1809C, SPRED1 nor SPRED2 segregated with CAL spots in the family. The results indicate that the familial CAL spots trait in this family is caused by a mutation in another gene, distinct from previous genes associated with CAL spots in these syndromes.Conclusion: We suggest that the atypical severe symptoms in the index patient may be caused by an additive effect on the F285L mutation in PTPN11 by another mutation, for example the NF1 R1809C or alternatively, the not yet identified gene mutation associated with CAL spots in this family.
Training neonatal skills with simulators?
Authors: Cavaleiro AP , Guimarães H , Calheiros FL 
Published: December 2008

AbstractAim: To compare two different ways of learning (self‐study vs. simulation sessions) the adequate steps to resuscitate a neonate in the 5th year undergraduate medical curriculum.Methods: One hundred and eighty students attending the 5‐week paediatrics rotation were enrolled; 115 were invited to participate in this study, but only 45 students completed it. After a 50‐min ‘neonatal resuscitation’ theoretical interactive class, students were randomly assigned into two groups: the first (n = 21) participated in a 30‐min supervised self‐study session, while the second (n = 24) attended a 30‐min neonatal resuscitation session using the Zoe (Gaumard® Inc., Miami, FL, USA) simulator.Results: Tests consisting of 50 multiple‐choice questions were taken before the theoretical class (pre‐theoretical test), before the self‐study or simulation session (pre‐test) and after this session (post‐test). Pre‐test and post‐test scores were similar in both groups (p = 0.118 and p = 0.263, respectively).Conclusion: Simulation‐based training of medical students in management of neonatal resuscitation do not led to significant differences on short‐term knowledge comparing with traditional method.
Antioxidant Potential of New Pyrazoline Derivatives to Prevent Oxidative Damage
Authors: Martins Daniele M. , Torres Bruna G. , Spohr Patrícia R. , Machado Pablo , Bonacorso Helio G. , Zanatta Nilo , Martins Marcos A. P. , Emanuelli Tatiana 
Published: December 2008

Abstract:  The antioxidant capacity of a series of six novel synthetic pyrazoline derivatives (i) 5‐hydroxy‐3‐methyl‐5‐trifluoromethyl‐4,5‐dihydro‐1H‐carbaldehyde‐pyrazole, (ii) 5‐hydroxy‐3‐methyl‐5‐trifluoromethyl‐4,5‐dihydro‐1H‐1‐acetyl‐pyrazole, (iii) 5‐hydroxy‐3‐methyl‐5‐trifluoromethyl‐4,5‐dihydro‐1H‐carboxyamide‐pyrazole, (iv) 5‐hydroxy‐3‐methyl‐5‐trifluoromethyl‐4,5‐dihydro‐1H‐1‐benzoyl‐pyrazole, (v) 5‐hydroxy‐3‐methyl‐5‐trifluoromethyl‐4,5‐dihydro‐1H‐1‐(2‐hydroxybenzoyl)‐pyrazole and (vi) 5‐hydroxy‐3‐methyl‐5‐trifluoromethyl‐4,5‐dihydro‐1H‐1‐(4‐methoxybenzoyl)‐pyrazole was evaluated as the capacity of compounds to transfer a hydrogen atom (protection against brain lipid peroxidation and glutathione oxidation) and their capacity to transfer a single electron [ferric‐reducing antioxidant power (FRAP) and 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging (DPPH) assays]. Compound 5 had the highest free radical scavenging capacity in the DPPH assay, while compound 2 had the highest FRAP value (P < 0.05). Only compounds 1, 4 and 5 protected against lipid peroxidation in rat brain homogenate. However, compound 5 was the most effective to prevent basal and iron‐, sodium nitroprusside‐ and H2O2‐stimulated lipid peroxidation (IC50 < 15 µM) and the only one effective to block glutathione oxidation‐mediated by H2O2 (at 150 µM). Our results indicate that compound 5 has the greatest potential to prevent oxidative damage in brain homogenates.
Osteopontin Mediates Dense Culture‐Induced Proliferation and Adhesion of Prostate Tumour Cells: Role of Protein Kinase C, p38 Mitogen‐Activated Protein Kinase and Calcium
Authors: Zhou Hong , Lu Ning , Chen Zhi‐Qiang , Song Qian‐Liu , Yu He‐Ming , Li Xue‐Jun 
Published: December 2008

Abstract:  Cells growing in high density were observed to undergo a variety of responses due to cell–cell contact, pericellular hypoxia, etc. In order to investigate the influence of cell density on cell proliferation and adhesion and to elucidate possible mechanisms, we tested the growth ability of human prostate tumour (PC‐3M) cells in dense culture and the influences of density on cell adhesion. Our results demonstrate that increasing cell density exerted stress on PC‐3M cells, which decreased cell proliferation in dense cultures, but tended to facilitate tumour metastasis since cell adhesion ability was elevated and the cells showed an increased growth rate after being moved to a favourable growth environment. We conclude that higher cell density‐mediated pericellular hypoxia was an important factor inducing expression of the intrinsic hypoxia marker osteopontin, another mechanism contributing to cell adhesion enhancement in PC‐3M cells. In addition, cell density enhanced adhesion ability due to the activation of p38 mitogen‐activated protein kinase (p38 MAPK) and protein kinase C. Intracellular calcium also played positive roles at least partially through activating p38 MAPK.
Antinociceptive Effect of a Novel Tosylpyrazole Compound in Mice
Authors: Oliveira Sara M. , Gewehr Camila , Dalmolin Gerusa D. , Cechinel Cleber A. , Wentz Alexandre , Lourega Rogério V. , Sehnem Ronan C. , Zanatta Nilo , Martins Marcos A. P. , Rubin Maribel A. , Bonacorso Helio G. , Ferreira Juliano 
Published: December 2008

Abstract:  Pain is the most common complaint in the medical field and the identification of compounds that can effectively treat painful states without induction of side‐effects remains a major challenge in biomedical research. The aim of the present study was to investigate the antinociceptive effect of a novel compound, 3‐(4‐fluorophenyl)‐5‐trifluoromethyl‐1H‐1‐tosylpyrazole (compound A) in several models of pain in mice and compare with those produced by the known trifluoromethyl‐containing pyrazole compound celecoxib. Compound A or celecoxib were administrated by oral (78–780 µmol/kg), intrathecal (9–22.5 nmol/site) or intracerebroventricular (9–22.5 nmol/site) routes. Oral administration of either compound A or celecoxib abolished the mechanical allodynia, but not the oedema caused by intraplantar injection of carrageenan. Similarly, compound A reduced the overt nociception, but not the oedema, produced by bradykinin or capsaicin. However, compound A (500 µmol/kg, orally) did not alter nociception nor oedema caused by intraplantar injection of prostaglandin E2 or glutamate, whereas celecoxib reduced only the nociception induced by the former. Moreover, oral and intrathecal administration of compound A or celecoxib also reduced the nociception induced by acetic acid. However, only celecoxib reduced the acetic acid‐induced nociception when it was injected by the intracerebroventricular route. Finally, neither compound A nor celecoxib was able to produce antinociceptive effect in the tail‐flick test or to alter the motor performance and the body temperature. Besides, compound A or celecoxib did not induce gastric lesion. Thus, compound A seems to be an interesting prototype for the development of novel analgesic drugs.
Dual Effects ofGinkgo bilobaLeaf Extract on Human Red Blood Cells
Authors: He Jing , Lin Juan , Li Jing , Zhang Jian‐Hong , Sun Xue‐Min , Zeng Cheng‐Ming 
Published: December 2008

Abstract: Extracts from the leaves ofGinkgo bilobahave been used in Chinese medicine for thousands of years. Today, various standardized preparations fromG. bilobaleaf extract have been developed.G. bilobaleaf extract, which contains flavonoids and terpenoids as the major biologically active components, has become one of the most popular and commonly used herbal remedies due to its wide spectrum of beneficial effects on health. In this study, we investigated the effects ofG. bilobaleaf extract on the properties of human red blood cells in the presence and absence of amyloid peptide (Aβ25‐35), peroxide and hypotonic stress. The results suggest thatG. bilobaleaf extract has a dual action, both protective and disruptive, on red blood cells, depending on whether an exogenous stress is present.G. bilobaleaf extract has a protective role on red blood cells against Aβ‐ and hypotonic pressure‐induced haemolysis, peroxide‐induced lipoperoxidation, as well as glutathione consumption and methaemoglobin formation. On the other hand,G. bilobaleaf extract also exhibited damage to red blood cells by increasing cell fragility, changing cellular morphology and inducing glutathione consumption and methaemoglobin formation, especially when applied at high doses. These anti‐ and pro‐oxidative activities of polyphenolic substances are thought to be involved in the dual function ofG. bilobaleaf extract. The results of this study suggest that high doses of herbal remedies and dietary supplements can be toxic to cells.