bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lysophosphatidic acid receptor 2/3‐mediated IL‐8‐dependent angiogenesis in cervical cancer cells
Authors: Chen Ruey‐Jien , Chen Shee‐Uan , Chou Chia‐Hung , Lin Ming‐Chieh 
Published: September 2011

AbstractThe expression of lysophosphatidic acid (LPA)‐specific receptors in cervical cancer has not been clearly defined. In this study, we identified LPA1, LPA2 and LPA3 receptors' mRNA in SiHa, HeLa and CaSki cell lines by RT‐PCR. These receptors were not associated with tumor cell proliferation in vitro. We then used a xenograph animal model to evaluate the effects of these receptors on in vivo cervical cancer tumorigenicity. When SiHa cells with different receptor expression patterns were seeded on the backs of SCID mice, the resulting knockout of both LPA2 and LPA3 significantly attenuated tumor growth; this decrease in tumor growth was found to be linked with decreased angiogenesis (microvessel density), suggesting that LPA2 and LPA3 are crucial for in vivo tumor growth through an angiogenic mechanism. We further investigated this mechanism of LPA receptor 2/3‐mediated angiogenic capability by analyzing angiogenic factors in protein lysates from receptor knockout tumors, by detecting interleukin (IL‐8) mRNA expression after treating with siRNA, by evaluating the biological role of LPA‐enhanced IL‐8 via endothelial cell tube formation, monolayer permeability, migration and cell growth assays, and by IL‐8 knockout xenograft mice modeling. We found that the angiogenesis is mediated through IL‐8. Finally, we evaluated the regulation pathways involved in LPA‐induced IL‐8 expression. We found that LPA receptor 2/3‐mediated IL‐8 expression occurs through Gi/PI3K/AKT, Gi/PKC and IκB/NF‐κB signaling. In conclusion, we propose that LPA2 and LPA3 might play an important role in cervical cancer tumor growth through IL‐8‐dependent angiogenesis.
Split Inteins: Nature’s Protein Ligases
Authors: Shah Neel H. , Muir Tom W. 
Published: September 2011

AbstractSplit inteins carry out a naturally occurring process known as protein trans‐splicing, where two protein fragments bind to form a catalytically competent enzyme, then catalyze their own excision and the ligation of their flanking sequences. In the past thirteen years since their discovery, chemists and biologists have utilized split inteins in exogenous contexts for a number of biotechnological applications centered around the formation of native peptide bonds. While many protein trans‐splicing technologies have emerged and flourished in recent years, several factors still limit their wide‐spread practical use. Here, we discuss the development, applications, and limitations of split intein‐based technologies and propose that further advancement in this field will require a more fundamental understanding of split intein structure and function.
Biomaterial testing for covered stent membranes: Evaluating thrombosis and restenosis potential
Authors: Weaver Jason D. , Ku David N. 
Published: September 2011

AbstractCovered stents may be able to prevent both thrombosis and restenosis, but new mechanically suitable and biocompatible materials are needed before this treatment option can become a reality. Hydrophilic polyvinyl alcohol (PVA) cryogels have desirable mechanical properties for covered stent membranes and may be able to provide a physical barrier to restenosis with low thrombogenicity. An in vitro flow loop with porcine blood was used to compare thrombus formation on different blood‐contacting biomaterials. PVA cryogels were found to maintain blood flow with low thrombogenicity and were significantly less thrombogenic than polyester (p < 0.05). The ability to prevent hyperplasic in‐growth was evaluated using a modified Boyden chamber cellular migration assay. PVA cryogel membranes used as a physical barrier were found to nearly eliminate cellular migration (p < 0.05) without cellular toxicity. Overall, this article demonstrates pivotal feasibility results for a covered stent membrane material that could prevent restenosis by means of a hydrogel barrier with low thrombogenicity. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Longitudinal evaluation of FGF23 changes and mineral metabolism abnormalities in a mouse model of chronic kidney disease
Authors: Stubbs Jason R , He Nan , Idiculla Arun , Gillihan Ryan , Liu Shiguang , David Valentin , Hong Yan , Quarles L Darryl 
Published: September 2011

Abstract
Fibroblast growth factor 23 (FGF23) is a phosphaturic and vitamin D-regulatory hormone of putative bone origin that is elevated in patients with chronic kidney disease (CKD). The mechanisms responsible for elevations of FGF23 and its role in the pathogenesis of chronic kidney disease-mineral bone disorder (CKD-MBD) remain uncertain. We investigated the association between FGF23 serum levels and kidney disease progression, as well as the phenotypic features of CKD-MBD in a Col4a3 null mouse model of human autosomal-recessive Alport syndrome. These mice exhibited progressive renal failure, declining 1,25(OH)2D levels, increments in parathyroid hormone (PTH) and FGF23, late-onset hypocalcemia and hyperphosphatemia, high-turnover bone disease, and increased mortality. Serum levels of FGF23 increased in the earliest stages of renal damage, before elevations in blood urea nitrogen (BUN) and creatinine. FGF23 gene transcription in bone, however, did not increase until late-stage kidney disease, when serum FGF23 levels were exponentially elevated. Further evaluation of bone revealed trabecular osteocytes to be the primary cell source for FGF23 production in late-stage disease. Changes in FGF23 mirrored the rise in serum PTH and the decline in circulating 1,25(OH)2D. The rise in PTH and FGF23 in Col4a3 null mice coincided with an increase in the urinary fractional excretion of phosphorus and a progressive decline in sodium-phosphate cotransporter gene expression in the kidney. Our findings suggest elevations of FGF23 in CKD to be an early marker of renal injury that increases before BUN and serum creatinine. An increased production of FGF23 by bone may not be responsible for early increments in FGF23 in CKD but does appear to contribute to FGF23 levels in late-stage disease. Elevations in FGF23 and PTH coincide with an increase in urinary phosphate excretion that likely prevents the early onset of hyperphosphatemia in the face of increased bone turnover and a progressive decline in functional renal mass. © 2012 American Society for Bone and Mineral Research
Oxygen versus sulfur: Structure and reactivity of substituted arsine oxides and arsine sulfides
Authors: Orthaber Andreas , Sax Alexander F. , Francesconi Kevin A. 
Published: September 2011

AbstractAlthough arsenic in its inorganic forms is a well know toxic agent, biotransformations in the environment and in the human body can produce organoarsenic compounds that are generally of much lower toxicity. Foremost among these products is a range of dimethylated arsine oxides and their analogous sulfides, which are crucial to the arsenic detoxification process. We have investigated the formation and interconversion of substituted and unsubstituted arsenicals (R22As(Z)R1, R2 = CH3, R1 = CH2CH2OH, CH2COOH; Z = S or O) with density functional theory (DFT)/B3LYP. Formation of isomers including a cyclic hydrogen bonded conformer is observed for the ethanol and acetate derivatives. Furthermore, investigating the reaction of arsine oxide with hydrogen sulfide revealed the formation of arsine sulfide via pentacoordinated trigonal bipyramidal intermediates. A tetragonal pyramidal transition state was located enabling exchange of equatorial and axial positions in the trigonal bipyramidal species. The reaction was proven exothermic for all studied substituents (ΔErxn −50 to −80 kJ/mol). This fundamental study shows that H2S easily leads to the formation of thio‐organoarsenicals. Conversion of arsine sulfides into their corresponding arsine oxides is experimentally accomplished with hydrogen peroxide, which could also be rationalized by means of ab initio calculations showing high exothermicity (ΔErxnca. −550 kJ/mol). Reactions are considered at different levels of theory (i.e., DFT, second and fourth order Møller–Plesset (MP) perturbation theory) including two solvation models for DFT, which show good agreement for resulting geometries and reaction energies. Hence, the widely used B3LYP/6‐31G** combination is a suitable method for the description of molecular organoarsenicals. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Sonographic diagnosis of a posttraumatic arteriocavernosal fistula resulting in high‐flow priapism
Authors: Keck Bastian , Lotter Gabriele , Wieland Wolf Ferdinand , Wullich Bernd , Uder Michael , Engehausen Dirk Gehrhard , Fritsche Hans Martin 
Published: September 2011

AbstractWe present a case of high‐flow priapism due to perineal trauma and subsequent arteriocavernosal fistula, which was diagnosed by sonography. Selective arterial embolization led to complete detumescence without compromising the patient's erectile function. Color Doppler sonography is an appropriate diagnostic tool to diagnose arteriocavernosal fistula. Selective arterial embolization is a safe and effective therapeutic option. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011;
Invasive implantation and intimate placental associations in a placentotrophic african lizard, Trachylepis ivensi (scincidae)
Authors: Blackburn Daniel G. , Flemming Alexander F. 
Published: September 2011

AbstractIn the viviparous lizard Trachylepis ivensi (Scincidae) of central Africa, reproducing females ovulate tiny ∼1 mm eggs and supply the nutrients for development by placental means. Histological study shows that this species has evolved an extraordinary placental pattern long thought to be confined to mammals, in which fetal tissues invade the uterine lining to contact maternal blood vessels. The vestigial shell membrane disappears very early in development, allowing the egg to absorb uterine secretions. The yolk is enveloped precocially by the trilaminar yolk sac and no isolated yolk mass or yolk cleft develops. Early placentas are formed from the chorion and choriovitelline membranes during the neurula through pharyngula stages. During implantation, cells of the chorionic ectoderm penetrate between uterine epithelial cells. The penetrating tissue undergoes hypertrophy and hyperplasia, giving rise to sheets of epithelial tissue that invade beneath the uterine epithelium, stripping it away. As a result, fetal epithelium entirely replaces the uterine epithelium, and lies in direct contact with maternal capillaries and connective tissue. Placentation is endotheliochorial and fundamentally different from that of all other viviparous reptiles known. Further, the pattern of fetal membrane development (with successive loss and re‐establishment of an extensive choriovitelline membrane) is unique among vertebrates. T. ivensi represents a new extreme in placental specializations of reptiles, and is the most striking case of convergence on the developmental features of viviparous mammals known. J. Morphol. 2011. © 2011 Wiley Periodicals, Inc.
Spermatophoric reaction reappraised: Novel insights into the functioning of the loliginid spermatophore based on Doryteuthis plei (Mollusca: Cephalopoda)
Authors: Marian José Eduardo A.R. 
Published: September 2011

AbstractDuring copulation, spermatophores produced by male coleoid cephalopods undergo the spermatophoric reaction, a complex process of evagination that culminates in the attachment of the spermatangium (everted spermatophore containing the sperm mass) on the female's body. To better understand this complicated phenomenon, the present study investigated the functional morphology of the spermatophore of the squid Doryteuthis plei applying in vitro analysis of the reaction, as well as light and electron microscopy investigation of spermatangia obtained either in vitro, or naturally attached on females. Hitherto unnoticed functional features of the loliginid spermatophore require a reappraisal of some important processes involved in the spermatophoric reaction. The most striking findings concern the attachment mechanism, which is not carried out solely by cement adhesive material, as previously believed, but rather by an autonomous, complex process performed by multiple structures during the spermatophoric reaction. During evagination, the ejaculatory apparatus provides anchorage on the targeted tissue, presumably due to the minute stellate particles present in the exposed spiral filament. Consequently, the ejaculatory apparatus maintains the attachment of the tip of the evaginating spermatophore until the cement body is extruded. Subsequently, the cement body passes through a complex structural rearrangement, which leads to the injection of both its viscid contents and pointed oral region onto the targeted tissue. The inner membrane at the oral region of the cement body contains numerous stellate particles attached at its inner side; eversion of this membrane exposes these sharp structures, which presumably adhere to the tissue and augment attachment. Several naturally attached spermatangia were found with their bases implanted at the deposition sites, and the possible mechanisms of perforation are discussed based on present evidence. The function of the complex squid spermatophore and its spermatophoric reaction is revisited in light of these findings. J. Morphol. 2012. © 2011 Wiley Periodicals, Inc.
In vivo MR quantification of superparamagnetic iron oxide nanoparticle leakage during low‐frequency‐ultrasound‐induced blood–brain barrier opening in swine
Authors: Liu Hao‐Li , Chen Pin‐Yuan , Yang Hung‐Wei , Wu Jia‐Shin , Tseng I‐Chou , Ma Yan‐Jung , Huang Chih‐Ying , Tsai Hong‐Chieh , Chen Shu‐Mei , Lu Yu‐Jen , Huang Chiung‐Yin , Hua Mu‐Yi , Ma Yunn‐Hwa , Yen Tzu‐Chen , Wei Kuo‐Chen 
Published: September 2011

AbstractPurpose:To verify that low‐frequency planar ultrasound can be used to disrupt the BBB in large animals, and the usefulness of MRI to quantitatively monitor the delivery of superparamagnetic iron oxide (SPIO) nanoparticles into the disrupted regions.Materials and Methods:Two groups of swine subjected to craniotomy were sonicated with burst lengths of 30 or 100 ms, and one group of experiment was also performed to confirm the ability of 28‐kHz sonication to open the BBB transcranially. SPIO nanoparticles were administered to the animals after BBB disruption. Procedures were monitored by MRI; SPIO concentrations were estimated by relaxivity mapping.Results:Sonication for 30 ms created shallow disruptions near the probe tip; 100‐ms sonications after craniotomy can create larger and more penetrating openings, increasing SPIO leakage ∼3.6‐fold than 30‐ms sonications. However, this was accompanied by off‐target effects possibly caused by ultrasonic wave reflection. SPIO concentrations estimated from transverse relaxation rate maps correlated well with direct measurements of SPIO concentration by optical emission spectrometry. We have also shown that transcranial low‐frequency 28‐kHz sonication can induce secure BBB opening from longitudinal MR image follow up to 7 days.Conclusion:This study provides valuable information regarding the use low‐frequency ultrasound for BBB disruption and suggest that SPIO nanoparticles has the potential to serve as a thernostic agent in MRI‐guided ultrasound‐enhanced brain drug delivery. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Correspondence of human visual areas identified using functional and anatomical MRI in vivo at 7 T
Authors: Sánchez‐Panchuelo Rosa M. , Francis Susan T. , Schluppeck Denis , Bowtell Richard W. 
Published: September 2011

AbstractPurpose:To study the correspondence of anatomically and functionally defined visual areas (primary visual cortex, V1, and motion selective area V5/human MT+) by using structural magnetic resonance imaging (MRI) and functional MRI (fMRI) in vivo at 7 T.Materials and Methods:Four subjects participated in this study. High‐resolution (≈0.4 mm isotropic) anatomical MRI was used to identify cortical regions based on their distinct cortical lamination. The optimal contrast for identifying heavily myelinated layers within gray matter was quantitatively assessed by comparing T1‐weighted magnetization‐prepared rapid gradient echo (MPRAGE) and T2*‐weighted, 3D fast‐low angle shot (FLASH) imaging. Retinotopic mapping was performed using GE‐based fMRI at 1.5 mm isotropic resolution to identify functional areas.Results:T2*‐weighted FLASH imaging was found to provide a significantly higher contrast‐to‐noise ratio, allowing visualization of the stria of Gennari in every slice of a volume covering the occipital cortex in each of the four subjects in this study. The independently derived boundary of V1, identified in the same subjects using retinotopic mapping by fMRI, closely matched the border of anatomically defined striate cortex in the human brain. Evidence of banding was also found within the functionally defined V5 area; however, we did not find a good correlation of this area, or the functionally identified subregion (MT), with the banded area.Conclusion:High‐resolution T2*‐weighted images acquired at 7 T can be used to identify myelinated bands within cortical gray matter in reasonable measurement times. Regions where a myelinated band was identified show a high degree of overlap with the functionally defined V1 area. J. Magn. Reson. Imaging 2012;287‐299. © 2011 Wiley Periodicals, Inc.
Perisynaptic aggrecan‐based extracellular matrix coats in the human lateral geniculate body devoid of perineuronal nets
Authors: Lendvai D. , Morawski M. , Brückner G. , Négyessy L. , Baksa G. , Glasz T. , Patonay L. , Matthews R.T. , Arendt T. , Alpár A. 
Published: September 2011

AbstractThe extracellular matrix surrounds different neuronal compartments in the mature nervous system. In a variety of vertebrates, most brain regions are loaded with a distinct type of extracellular matrix around the somatodendritic part of neurons, termed perineuronal nets. The present study reports that chondrotin sulfate proteoglycan‐based matrix is structured differently in the human lateral geniculate body. Using various chondrotin sulfate proteoglycan‐based extracellular matrix antibodies, we show that perisomatic matrix labeling is rather weak or absent, whereas dendrites are contacted by axonal coats appearing as small, oval structures. Confocal laser scanning microscopy and electron microscopy demonstrated that these typical structures are associated with synaptic loci on dendrites. Using multiple labelings, we show that different chondrotin sulfate proteoglycan components of the extracellular matrix do not associate exclusively with neuronal structures but possibly associate with glial structures as well. Finally, we confirm and extend previous findings in primates that intensity differences of various extracellular matrix markers between magno‐ and parvocellular layers reflect functional segregation between these layers in the human lateral geniculate body. © 2011 Wiley Periodicals, Inc.
Neuroprotection by hypoxic preconditioning involves upregulation of hypoxia‐inducible factor‐1 in a prenatal model of acute hypoxia
Authors: Giusti Sebastián , Fiszer de Plazas Sara 
Published: September 2011

AbstractThe molecular pathways underlying the neuroprotective effects of preconditioning are promising, potentially drugable targets to promote cell survival. However, these pathways are complex and are not yet fully understood. In this study we have established a paradigm of hypoxic preconditioning based on a chick embryo model of normobaric acute hypoxia previously developed by our group. With this model, we analyzed the role of hypoxia‐inducible factor‐1α (HIF‐1α) stabilization during preconditioning in HIF‐1 signaling after the hypoxic injury and in the development of a neuroprotective effect against the insult. To this end, we used a pharmacological approach, based on the in vivo administration of positive (Fe2+, ascorbate) and negative (CoCl2) modulators of the activity of HIF‐prolyl hydroxylases (PHDs), the main regulators of HIF‐1. We have found that preconditioning has a reinforcing effect on HIF‐1 accumulation during the subsequent hypoxic injury. In addition, we have also demonstrated that HIF‐1 induction during hypoxic preconditioning is necessary to obtain an enhancement in HIF‐1 accumulation and to develop a tolerance against a subsequent hypoxic injury. We provide in vivo evidence that administration of Fe2+ and ascorbate modulates HIF accumulation, suggesting that PHDs might be targets for neuroprotection in the CNS. © 2011 Wiley Periodicals, Inc.
Mechanical tissue optical clearing technique increases imaging resolution and contrast through Ex vivo porcine skin
Authors: Izquierdo‐Román Alondra , Vogt William C. , Hyacinth Leeanna , Rylander Christopher G. 
Published: September 2011

AbstractBackground and ObjectivesMechanical tissue optical clearing permits light delivery deeper into turbid tissue, which may improve current optical diagnostics and laser‐based therapeutic techniques. We investigated the effects of localized compression on brightfield imaging through ex vivo porcine skin by evaluating resolution and contrast of a target positioned beneath native, mechanically compressed, or chemically cleared specimens. We also evaluated the effects of indentation on dynamic tissue thickness and light transmission.Study Design/MethodsA 5 mm diameter, hemispherically tipped, manual load transducer was used to compress specimens using 2–44 N for 60 seconds. Chemically cleared specimens were immersed for 1 hour in glycerol or dimethyl sulfoxide. A USAF 1951 resolution target was positioned beneath specimens and imaged using brightfield microscopy. Resolution and contrast of target features were analyzed. In separate experiments, a mechanical test instrument was used to compress and hold specimens at a final thickness while measuring applied load and light transmission.ResultsImage intensity profiles showed that while uncompressed skin did not allow resolution of any target, localized compression allowed maximum resolution up to a line width of 173 ± 21 µm. Mechanical clearing achieved up to four times higher maximum resolution and 2–3 times higher contrast sensitivity than chemical immersion. Resolving capability was highly correlated with compressive tissue strain. Light transmission increased during tissue compression, but also increased while holding final thickness constant.ConclusionLocalized compression is an effective technique for increasing resolution and contrast of target features through tissue and may improve light‐based diagnostics. Thickness reduction and other mechanisms appear to contribute to this effect. Lasers Surg. Med. © 2011 Wiley‐Liss, Inc.