bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of splice correction by cell‐penetrating peptide nucleic acids
Authors: El‐Andaloussi Samir , Johansson Henrik J. , Lundberg Pontus , Langel Ülo 
Published: August 2006

AbstractBackgroundDirecting splicing using oligonucleotides constitutes a promising therapeutic tool for a variety of diseases such as β‐thalassemia, cystic fibrosis, and certain cancers. The rationale is to block aberrant splice sites, thus directing the splicing of the pre‐mRNA towards the desired protein product. One of the difficulties in this setup is the poor bioavailability of oligonucleotides, as the most frequently used transfection agents are unsuitable for in vivo use. Here we present splice‐correcting peptide nucleic acids (PNAs), tethered to a variety of cell‐penetrating peptides (CPPs), evaluating their mechanism of uptake and ability to correct aberrant splicing.MethodsHeLa cells stably expressing luciferase containing an aberrant splice site were used. A previously described PNA sequence, capable of correcting the aberrant splicing, was conjugated to the CPPs, Tat, penetratin and transportan, via a disulfide bridge. The ability of the CPP‐PNA conjugates to correct splicing was measured, and membrane disturbance and cell viability were evaluated using LDH leakage and WST‐1 assays. Lysosomotropic agents, inhibition of endocytosis at 4 °C and confocal microscopy were used to investigate the importance of endocytosis in the uptake of the cell‐penetrating PNAs.ResultsAll the three CPPs were able to promote PNA translocation across the plasma membrane and induce splice correction. Transportan (TP) was the most potent vector and significantly restored splicing in a concentration‐dependent manner. Interestingly, TP also rendered a concentration‐dependent splice correction in serum, in contrast to Tat and penetratin. Addition of the lysosomotrophic agent chloroquine increases the splice correction efficacy of the CPP‐PNA conjugates up to 4‐fold, which together with experiments at 4 °C and the visual information from confocal microscopy, indicate that the mechanism of uptake responsible for internalization of CPP‐PNA conjugates is mainly endocytic. Finally, co‐localization studies with dextran further indicate that conjugates, at least in the case of TP, internalize via endocytosis and in particular macropinocytosis.ConclusionsThese data demonstrate that CPPs can be used for the delivery of splice‐correcting PNAs, with potential to be used as a therapeutic approach for regulating splicing in a variety of diseases. Transportan presents itself as the overall most suitable vector in this study, generating the most efficient conjugates for splice correction. Copyright © 2006 John Wiley & Sons, Ltd.
Managing discontinuity in academic medical centers: Strategies for a safe and effective resident sign‐out
Authors: Vidyarthi Arpana R. , Arora Vineet , Schnipper Jeffrey L. , Wall Susan D. , Wachter Robert M. 
Published: August 2006

AbstractBACKGROUNDRestrictions in the hours residents can be on duty have resulted in increased sign‐outs, that is, transfer of patient care information and responsibility from one physician to a cross‐coverage physician, leading to discontinuity in patient care. This sign‐out process, which occurs primarily in the inpatient setting, traditionally has been informal, unstructured, and idiosyncratic. Although studies show that discontinuity may be harmful to patients, this is little data to assist residency programs in redesigning systems to improve sign‐out and manage the discontinuity.PURPOSEThis article reviews the relevant medical literature, current practices in non–health professions in managing discontinuity, and summarizes the existing practice and experiences at 3 academic internal medicine hospitalist‐based programs.CONCLUSIONSWe provide recommendations and strategies for best practices to design safe and effective sign‐out systems for residents that may also be useful to hospitalists working in academic and community settings. Journal of Hospital Medicine 2006;1:257–266. © 2006 Society of Hospital Medicine.
Nicotine reverses adult‐onset hypothyroidism‐induced impairment of learning and memory: Behavioral and electrophysiological studies
Authors: Alzoubi K.H. , Aleisa A.M. , Gerges N.Z. , Alkadhi K.A. 
Published: August 2006

AbstractNicotine alleviates cognitive impairment associated with a variety of health conditions. We examined the effect of chronic nicotine treatment on adult‐onset hypothyroidism‐induced impairment of learning and memory in rats. Hypothyroidism was induced by surgical removal of thyroid glands (thyroidectomy). One month later, chronic nicotine treatment (1 mg/kg sc, twice/day) was instituted for 4–6 weeks. Test of hippocampus‐dependent spatial learning and memory in the radial arm water maze showed that hypothyroidism impaired learning as well as short‐term and long‐term memory retention. Chronic nicotine treatment reversed the hypothyroidism‐induced learning and memory impairment. In normal rats, chronic nicotine treatment had no effect on learning and memory. Extracellular recordings from the CA1 region of anesthetized hypothyroid rats showed severe reduction of both early‐phase and late‐phase long‐term potentiation (LTP) magnitude, which was reversed in nicotine‐treated hypothyroid rats. These results show that chronic nicotine treatment prevents hypothyroidism‐induced impairment of spatial cognition and LTP. © 2006 Wiley‐Liss, Inc.
Estrogen treatment of spinal cord injury attenuates calpain activation and apoptosis
Authors: Sribnick Eric Anthony , Matzelle Deborah Denise , Ray Swapan Kumar , Banik Naren Lal 
Published: August 2006

AbstractSpinal cord injury (SCI) is a devastating neurologic injury, and currently, the only recommended pharmacotherapy is high‐dose methylprednisolone, which has limited efficacy. Estrogen is a multi‐active steroid with anti‐oxidant and anti‐apoptotic effects. Estrogen may modulate intracellular Ca2+ and prevent inflammation. For this study, male rats were divided into three groups. Sham‐group animals received a laminectomy at T12. Injured rats received both laminectomy and 40 gram centimeter force SCI. Estrogen‐group rats received 4 mg/kg 17β‐estradiol (estrogen) at 15 min and 24 hr post‐injury, and vehicle‐group rats received equal volumes of dimethyl sulfoxide. Animals were sacrificed at 48 hr post‐injury, and 1‐cm segments of the lesion, rostral penumbra, and caudal penumbra were excised. The degradation of 68 kD neurofilament protein (NFP) and estrogen receptors (ER) was examined by Western blot analysis. Protein levels of calpain and the activities of calpain and caspase‐3 were also examined. Levels of cytochrome c were determined in both cytosolic and mitochondrial fractions. Cell death with DNA fragmentation was examined using the TUNEL assay. At the lesion, samples from both vehicle and estrogen treated animals showed increased levels of 68 kD NFP degradation, calpain content, calpain activity, cytochrome c release, and degradation of ERα and ERβ, as compared to sham. In the caudal penumbra, estrogen treatment significantly attenuated 68 kD NFP degradation, calpain content, calpain activity, levels of cytosolic cytochrome c, and ERβ degradation. At the lesion, vehicle‐treated animals displayed more TUNEL+ cells, and estrogen treatment significantly attenuated this cell death marker. We conclude that estrogen may inhibit cell death in SCI through calpain inhibition. © 2006 Wiley‐Liss, Inc.
Heavy metal concentrations and correlations in rain‐fed farm soils of Sifangwu village, central Gansu Province, China
Authors: Gou X. , Li Y. , Wang G. 
Published: August 2006

AbstractConcentrations of copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr), mercury (Hg), arsenic (As), organic carbon (abbreviated to OC) content and pH were measured in rain‐fed farm soils collected in Sifangwu Village which is located central Gansu Province, Northwest China. Concentrations of Cu, Pb, Cd, Hg and As are higher than the background values in grey calcareous soil. Cd concentration exceeds the Threshold of Secondary Environmental Quality Standard for Soil in China by 261 per cent. By bivariate analysis, it was found that OC does not correlate with heavy metal in the village. This is due to the semiarid conditions and agricultural activities. Principal component analysis (PCA) was used to assess the soil data, applying varimax rotation with Kaiser Normalization. The result shows that the data set is defined for three latent components. 1) PC1, which consists of Cu and Cr, and what is characterized as a component subject to strong lithological influence. 2) PC2, dominantly loaded by OC, Pb and Cd, is linked to agricultural influence, i.e. fertilization and cultivation. 3) PC3, the heavy metals Hg and As, in this component are from aerial deposition, thus this PC is named the atmospheric factor. Because PC1 explains 45·026 per cent of total variance, the source of the heavy metal in topsoil in the study area is assumed to be mainly derived from the lithology. Copyright © 2006 John Wiley & Sons, Ltd.
Complete 1H, 13C and 15N NMR assignment of tirapazamine and related 1,2,4‐benzotriazine N‐oxides
Authors: Boyd Maruta , Hay Michael P. , Boyd Peter D. W. 
Published: August 2006

Abstract1H, 13C and 15N NMR measurements (1D and 2D including 1H15N gs‐HMBC) have been carried out on 3‐amino‐1, 2,4‐benzotriazine and a series of N‐oxides and complete assignments established. N‐Oxidation at any position resulted in large upfield shifts of the corresponding N‐1 and N‐2 resonances and downfield shifts for N‐4 with the exception of the 3‐amino‐1,2,4‐benzotriazine 1‐oxide in which a small upfield shift of N‐4 was observed. Density functional GIAO calculations of the 15N and 13C chemical shifts [B3LYP/6‐31G(d)//B3LYP/6‐311 + G(2d,p)] gave good agreement with experimental values confirming the assignments. The combination of 13C and 15N NMR provides an unambiguous method for assigning the 1H and 13C resonances of N‐oxides of 1,2,4‐benzotriazines. Copyright © 2006 John Wiley & Sons, Ltd.
Transcriptome profiling of the tubular porcine conceptus identifies the differential regulation of growth and developmentally associated genes
Authors: Blomberg Le Ann , Garrett Wesley M. , Guillomot Michel , Miles Jeremy R. , Sonstegard Tad S. , Van Tassell Curtis P. , Zuelke Kurt A. 
Published: August 2006

AbstractGastrulation and trophectoderm elongation of the porcine conceptus coincide with peak conceptus estrogen secretion from gestational day 11 to day 12. The current study aim was to identify genes required for elongation by defining the transcriptome profile of this dynamic tubular stage. The gastrulation and proliferative status of ovoid, tubular, and filamentous conceptuses were also examined. Polarization of the embryonic disc and growth throughout the conceptus were evident. An unamplified and two distinct amplified serial analysis of gene expression (SAGE) libraries were generated from tubular conceptus mRNA. Comparing the three libraries at 12,000 tags/library indicated small‐amplified RNA‐SAGE was a reliable amplification procedure. The unamplified library was increased to 42,415 tags and statistical analyses of tag frequencies with previously generated ovoid and filamentous libraries revealed the differential expression (P < 0.05) of 483 and 364 tags between ovoid:tubular or tubular:filamentous libraries, respectively. Annotated transcripts known to be involved in development and also potentially regulated by estrogen (cytokeratins 8 and 18, stratifin, midkine, and glycolytic enzymes) were further analyzed by real‐time PCR. The majority of glycolytic enzyme transcripts were constitutively expressed or downregulated at the filamentous stage. Likewise, cytokeratin mRNAs were less abundant in filamentous conceptuses, whereas stratifin and midkine were more abundant in tubular conceptuses. Analysis of protein revealed distinct expression patterns for cytokeratin 18, stratifin, and midkine. The function(s) of these factors and potential modulation by estrogen clearly needs to be elucidated to understand their physiological role in normal conceptus development. Mol. Reprod. Dev. 73: 1491–1502, 2006. © 2006 Wiley‐Liss, Inc.
Effects of hyaluronan, BSA, and serum on bovine embryo in vitro development, ultrastructure, and gene expression patterns
Authors: Palasz A. T. , Rodriguez‐Martinez H. , Beltran‐Breña P. , Perez‐Garnelo S. , Martinez M. F. , Gutierrez‐Adan A. , De la Fuente J. 
Published: August 2006

AbstractEffects of hyaluronan (HA), BSA, and FCS on in vitro development, ultrastructure, and mRNA transcription of four developmentally important genes: apoptosis (Bax), oxidative stress (SOX), growth factor (IGF‐II), and cell‐to‐cell adhesion (Ecad) were examined. Two biological origin HA, Hylartil and Hyonate and one produced by fermentation (f‐HA) MAP‐5 were tested. Embryos were cultured in SOF medium with 0.4% BSA or with 0.4% BSA and 10% FCS. HA was added 96 hr post insemination (pi) to half of the embryos from each culture group. Embryo development was not affected by either HA preparation, however, hatching rates were higher in Hyalartil and MAP‐5 than in control and Hyonate (P < 0.05). There was no effect of HA on number of blastocysts developed in SOF + BSA. However, more blastocysts developed in SOF + BSA + f‐HA than in SOF +  BSA + FCS or with BSA + FCS + f‐HA. HA added to SOF + BSA, increased level of expression of epidermal growth factor (EGF)‐II and decreased the levels of expression of BAX, SOX, and Ecad (P < 0.05). Presence of FCS increased the levels of SOX and decreased the level of IGF‐II (P < 0.05) and the addition of f‐HA to SOF containing FCS showed no effect on the level of transcription of any analyzed genes. The fine structure of embryos cultured with f‐HA irrespective of protein sources used was clearly improved. In summary, f‐HA added 96 hr pi to SOF supplemented with BSA but not FCS improved development, molecular composition and fine structure of bovine embryos. Mol. Reprod. Dev. 73: 1503–1511, 2006. © 2006 Wiley‐Liss, Inc.
Subzero water transport characteristics and optimal rates of freezing rhesus monkey (Macaca mulatta) ovarian tissue
Authors: Li G. , Thirumala S. , Leibo S.P. , Devireddy R.V. 
Published: August 2006

AbstractThe purpose of the present study was to examine the effect of two different suprazero (room temperature +25°C to +4°C) cooling conditions on the measured water transport response of primate (Macaca mulatta) ovarian tissue in the presence and absence of cryoprotective agents (CPAs). Freshly collected Macaca mulatta (rhesus monkey) ovarian tissue sections were cooled at either 0.5°C/min or 40°C/min from 25 to 4°C. A shape independent differential scanning calorimeter (DSC) technique was then used to measure the volumetric shrinkage during freezing of ovarian tissue sections at a freezing rate of 5°C/min in the presence and absence of three different CPAs (0.85 M glycerol, 0.85 M dimethylsulfoxide, and 0.85 M ethylene glycol). Thus, water transport during freezing of primate ovarian tissue was obtained at eight different conditions (i.e., at four different freezing media with two different suprazero cooling conditions). The water transport response of ovarian tissue cooled rapidly from 25 to 4°C was significantly different (P < 0.01) than that of slow cooled tissue, in the freezing media without CPAs and with dimethylsulfoxide. However, the differences in the measured water transport response due to the imposed suprazero cooling conditions were reduced with the addition of glycerol and ethylene glycol (statistically different with P < 0.05). By fitting a model of water transport to the experimentally obtained volumetric shrinkage data the best‐fit membrane permeability parameters (Lpg and ELp) were determined. The best‐fit parameters of water transport in primate ovarian tissue sections ranged from: Lpg = 0.7 to 0.15 µm/min‐atm and ELp = 22.1 to 32.1 kcal/mol (the goodness of fit parameter, R2 > 0.96). These parameters suggest that the “optimal rates of cryopreservation” for ovarian tissue are significantly dependent upon suprazero cooling conditions and the choice of CPA. Mol. Reprod. Dev. 73: 1600–1611, 2006. © 2006 Wiley‐Liss, Inc.
Differing mechanisms of cAMP‐ versus seawater‐induced oocyte maturation in marine nemertean worms II. The roles of tyrosine kinases and phosphatases
Authors: Stricker Stephen A. , Smythe Toni L. 
Published: August 2006

AbstractInstead of blocking oocyte maturation as it does in most animals, cAMP causes oocytes of marine nemertean worms to initiate maturation (=germinal vesicle breakdown, “GVBD”). To characterize cAMP‐induced GVBD in nemerteans, inhibitors of tyrosine kinase signaling were tested on Cerebratulus sp. oocytes that had been incubated in cAMP‐elevating drugs versus seawater (SW) alone. Such tests yielded similar results for Src‐like tyrosine kinase blockers, as the inhibitors prevented mitogen‐activated protein kinase (MAPK) activation without stopping either GVBD or maturation‐promoting factor (MPF) activation in both SW and cAMP‐elevating treatments. Alternatively, genistein, a general tyrosine kinase antagonist, and piceatannol, an inhibitor of the tyrosine kinase Syk, reduced GVBD and MAPK/MPF activities in SW‐, but not cAMP‐induced maturation. Similarly, inhibitors of the human epidermal growth factor receptor‐2 (HER‐2) tyrosine kinase prevented GVBD and MAPK/MPF activations in oocytes treated with SW, but not with cAMP‐elevating drugs. Antagonists of either protein tyrosine phosphatases (PTPs) or the dual‐specificity phosphatase Cdc25 also reduced GVBD and MAPK/MPF activities in SW‐treated oocytes without generally affecting cAMP‐induced maturation. Collectively, these data suggest cAMP triggers GVBD via pathways that do not require MAPK activation or several components of tyrosine kinase signaling. In addition, such differences in tyrosine kinase cascades, coupled with the dissimilar patterns of Ser/Thr kinase signaling described in the accompanying study, indicate that nemertean oocytes are capable of utilizing multiple mechanisms to activate MPF during GVBD. Mol. Reprod. Dev. 73: 1564–1577, 2006. © 2006 Wiley‐Liss, Inc.
Differing mechanisms of cAMP‐ versus seawater‐induced oocyte maturation in marine nemertean worms I. The roles of serine/threonine kinases and phosphatases
Authors: Stricker Stephen A. , Smythe Toni L. 
Published: August 2006

AbstractUnlike in most animals, oocytes of marine nemertean worms initiate maturation (=germinal vesicle breakdown, GVBD) following an increase, rather than a decrease, in intraoocytic cAMP. To analyze how serine/threonine (Ser/Thr) kinase cascades involving mitogen‐activated protein kinase (MAPK), maturation‐promoting factor (MPF), cAMP‐dependent protein kinase (PKA), and phosphatidylinositol 3‐kinase (PI3K) regulate nemertean GVBD, oocytes of Cerebratulus sp. were treated with pharmacological modulators and stimulated with cAMP‐elevating drugs or seawater (SW) alone. Both cAMP elevators and SW triggered GVBD while activating MAPK, its target p90Rsk, and MPF. Similarly, neither cAMP‐ nor SW‐induced GVBD was affected by several Ser/Thr phosphatase inhibitors, and both stimuli apparently accelerated GVBD via a MAPK‐independent, PI3K‐dependent mechanism. However, inhibitors of Raf‐1, a kinase that activates MAPK kinase, blocked GVBD and MAPK activation during SW‐, but not cAMP‐induced maturation. In addition, MPF blockers more effectively reduced GVBD and MAPK activity in SW versus in cAMP‐elevating treatments. Moreover, the two maturation‐inducing stimuli yielded disparate patterns of PKA‐related MAPK activations and phosphorylations of putative PKA substrates. Collectively, such findings suggest that in maturing oocytes of Cerebratulus sp., Ser/Thr kinase cascades differ during cAMP‐ versus SW‐induced GVBD in several ways, including MAPK activation modes, MPF‐feedback loops, and PKA‐related signaling pathways. Additional differences in cAMP‐ versus SW‐induced oocyte maturation are also described in the accompanying study that deals with the roles of tyrosine kinase signaling during GVBD. Mol. Reprod. Dev. 73: 1578–1590, 2006. © 2006 Wiley‐Liss, Inc.
Blood velocity assessment using 3D bright‐blood time‐resolved magnetic resonance angiography
Authors: Miraux Sylvain , Franconi Jean‐Michel , Thiaudière Eric 
Published: August 2006

AbstractBlood velocity is a functional parameter that is not easily assessed noninvasively, especially in small animals. A new noninvasive method that uses magnetic resonance angiography (MRA) to measure blood flows is proposed. This method is based on the time‐of‐flight (TOF) phenomenon. By initially suppressing the signal from the stationary spins in the area of interest, it is possible to sequentially visualize only the signal from the moving spins entering a given volume. With this method, 3D cine images of the blood flow can be generated by positive contrast, with unparalleled spatial (<200 μm) and temporal resolutions (<10 ms/image). As a result, it is possible to measure flow in sinuous paths. The present method was applied in vivo to measure the blood velocity in mouse carotid arteries. Because of its robustness and simplicity of implementation, this method has numerous potential applications for fundamental studies in small animal models. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Modified Alderman‐Grant resonator with high‐power stability for proton electron double resonance imaging
Authors: Petryakov Sergey , Samouilov Alexandre , Roytenberg Michael , Li Haihong , Zweier Jay L. 
Published: August 2006

AbstractProton‐electron double resonance imaging (PEDRI) requires a dual EPR/NMR resonator. In order to saturate electron spins, long high‐power RF EPR pulses are needed. Dissipated power causes resonator and sample heating, resulting in instability of the resonator frequency and coupling, which in turn causes a reduction in sensitivity. To overcome this problem, we designed, built, and tested a modified Alderman‐Grant (MAG) resonator for in vivo and in vitro applications. We improved the temperature stability by using fused quartz in critical structural components of the resonator and employing a design that minimized moving parts. All of the components of the resonator and matching circuit, including coupling capacitors, were rigidly positioned on the surface of the quartz tube. Electrical coupling circuitry between the feeding cable and resonator was employed to provide independent coupling and tuning adjustments, which improved the ease and speed of operation. The equivalent schematic of the matching circuit is presented along with calculations of critical parameters. The resonator exhibits no frequency shift with 20 W of continuous power irradiation, and can handle intermittent power of 60 W for up to 3 min without detuning, enabling stable and reliable data acquisition for PEDRI of biological samples. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.