bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis Study toward Mayamycin
Authors: Wu Kui , Wang Meining , Yao Qizheng , Zhang Ao 
Published: January 2013

AbstractNatural product mayamycin is the first example in the angucycline class featuring a C‐glycoside linkage at the C5‐position of the benz[a]anthracenone core with remarkable biological activities. We successfully synthesized the two retrosynthetic fragments, but found that the final C‐glycosylation did not occur. Alternatively, an A‐ring saturated aglycon was prepared, but the proposed C‐glycosylation still did not proceed. Finally, a simplified substrate was used and the subsequent C‐glycosylation went through smoothly, giving a two‐ring less analogue of mayamycin.
Synthesis and Cytotoxic Evaluation of Novel Platinum(II) Complexes with C2‐Asymmetric and C2‐Symmetric Chiral Vicinal Diamines
Authors: Zhang Chen , Liu Hongrui , Yang Qing , Chang Jun , Sun Xun 
Published: January 2013

AbstractA series of new platinum(II) complexes with C2‐asymmetric and C2‐symmetric 1,2‐diamines were designed and synthesized by convenient methods, involving samarium diiodide induced reductive coupling as the key step. The results of cytotoxicity showed that compounds (R,R)‐11a and (S,S)‐11a, two novel platinum(II) complexes with asymmetric 1,2‐diamines, exhibited more potent cytotoxicity than that of oxaliplatin against all leukemia cell lines. Interestingly, (R,R)‐11a and (S,S)‐11a demonstrated less potent activity against three solid cancer cell lines than that of oxaliplatin, which indicated that these two compounds may only selectively inhibit the leukemia cell lines. In contrast, (R,R)‐15a and (S,S)‐15a, two platinum(II) complexes with symmetric 1,2‐diamines, showed similar cytotoxicity to that of oxaliplatin against all leukemia cell lines and more potent activity against solid cancer cell lines. Further flow cytometry data indicated that (R,R)‐11a could obviously arrest leukemia K562 cells in G2/M phases.
Forebrain GABAergic projections to locus coeruleus in mouse
Authors: Dimitrov Eugene L. , Yanagawa Yuchio , Usdin Ted B. 
Published: January 2013

AbstractThe noradrenergic locus coeruleus (LC) regulates arousal, memory, sympathetic nervous system activity, and pain. Forebrain projections to LC have been characterized in rat, cat, and primates, but not systematically in mouse. We surveyed mouse forebrain LC‐projecting neurons by examining retrogradely labeled cells following LC iontophoresis of Fluoro‐Gold and anterograde LC labeling after forebrain injection of biotinylated dextran amine or viral tracer. Similar to other species, the central amygdalar nucleus (CAmy), anterior hypothalamus, paraventricular nucleus, and posterior lateral hypothalamic area (PLH) provide major LC inputs. By using mice expressing green fluorescent protein in γ‐aminobutyric acid (GABA)ergic neurons, we found that more than one‐third of LC‐projecting CAmy and PLH neurons are GABAergic. LC colocalization of biotinylated dextran amine, following CAmy or PLH injection, with either green fluorescent protein or glutamic acid decarboxylase (GAD)65/67 immunoreactivity confirmed these GABAergic projections. CAmy injection of adeno‐associated virus encoding channelrhodopsin‐2‐Venus showed similar fiber labeling and association with GAD65/67‐immunoreactive (ir) and tyrosine hydroxylase (TH)‐ir neurons. CAmy and PLH projections were densest in a pericoerulear zone, but many fibers entered the LC proper. Close apposition between CAmy GABAergic projections and TH‐ir processes suggests that CAmy GABAergic neurons may directly inhibit noradrenergic principal neurons. Direct LC neuron targeting was confirmed by anterograde transneuronal labeling of LC TH‐ir neurons following CAmy or PLH injection of a herpes virus that expresses red fluorescent protein following activation by Cre recombinase in mice that express Cre recombinase in GABAergic neurons. This description of GABAergic projections from the CAmy and PLH to the LC clarifies important forebrain sources of inhibitory control of central nervous system noradrenergic activity. J. Comp. Neurol. 521:2373–2397, 2013. © 2012 Wiley Periodicals, Inc.
Differential dendritic targeting of AMPA receptor subunit mRNAs in adult rat hippocampal principal neurons and interneurons
Authors: Cox David J. , Racca Claudia 
Published: January 2013

AbstractIn hippocampal neurons, AMPA receptors (AMPARs) mediate fast excitatory postsynaptic responses at glutamatergic synapses, and are involved in various forms of synaptic plasticity. Dendritic local protein synthesis of selected AMPAR subunit mRNAs is considered an additional mechanism to independently and rapidly control the strength of individual synapses.We have used fluorescent in situ hybridization and immunocytochemistry to analyze the localization of AMPAR subunit (GluA1–4) mRNAs and their relationship with the translation machinery in principal cells and interneurons of the adult rat hippocampus. The mRNAs encoding all four AMPAR subunits were detected in the somata and dendrites of CA3 and CA1 pyramidal cells and those of six classes of CA1 γ‐aminobutyric acid (GABA)ergic interneurons. GluA1–4 subunit mRNAs were highly localized to the apical dendrites of pyramidal cells, whereas in interneurons they were present in multiple dendrites. In contrast, in the dentate gyrus, GluA1–4 subunit mRNAs were virtually restricted to the somata and were absent from the dendrites of granule cells. These different regional and cell type‐specific labeling patterns also correlated with the localization of markers for components of the protein synthesis machinery. Our results support the local translation of GluA1–4 mRNAs in dendrites of hippocampal pyramidal cells and CA1 interneurons but not in granule cells of the dentate gyrus. Furthermore, the regional and cell type‐specific differences we observed suggest that each cell type uses distinct ways of regulating the local translation of AMPAR subunits. J. Comp. Neurol. 521:1954–2007, 2013. © 2012 Wiley Periodicals, Inc.
Selective coexpression of synaptic proteins, α‐synuclein, cysteine string protein‐α, synaptophysin, synaptotagmin‐1, and synaptobrevin‐2 in vesicular acetylcholine transporter‐immunoreactive axons in the guinea pig ileum
Authors: Sharrad Dale F. , Gai Wei‐Ping , Brookes Simon J.H. 
Published: January 2013

AbstractParkinson's disease is a neurodegenerative disorder characterized by Lewy bodies and neurites composed mainly of the presynaptic protein α‐synuclein. Frequently, Lewy bodies and neurites are identified in the gut of Parkinson's disease patients and may underlie associated gastrointestinal dysfunctions. We recently reported selective expression of α‐synuclein in the axons of cholinergic neurons in the guinea pig and human distal gut; however, it is not clear whether α‐synuclein expression varies along the gut, nor how closely expression is associated with other synaptic proteins. We used multiple‐labeling immunohistochemistry to quantify which neurons in the guinea pig ileum expressed α‐synuclein, cysteine string protein‐α (CSPα), synaptophysin, synaptotagmin‐1, or synaptobrevin‐2 in their axons. Among the 10 neurochemically defined axonal populations, a significantly greater proportion of vesicular acetylcholine transporter‐immunoreactive (VAChT‐IR) varicosities (80% ± 1.7%, n = 4,P< 0.001) contained α‐synuclein immunoreactivity, and a significantly greater proportion of α‐synuclein‐IR axons also contained VAChT immunoreactivity (78% ± 1.3%, n = 4) compared with any of the other nine populations (P< 0.001). Among synaptophysin‐, synaptotagmin‐1‐, synaptobrevin‐2‐, and CSPα‐IR varicosities, 98% ± 0.7%, 96% ± 0.7%, 88% ± 1.6%, and 85% ± 2.9% (n = 4) contained α‐synuclein immunoreactivity, respectively. Among α‐synuclein‐IR varicosities, 96% ± 0.9%, 99% ± 0.6%, 83% ± 1.9%, and 87% ± 2.3% (n = 4) contained synaptophysin‐, synaptotagmin‐1‐, synaptobrevin‐2‐, and CSPα immunoreactivity, respectively. We report a close association between the expression of α‐synuclein and the expression of other synaptic proteins in cholinergic axons in the guinea pig ileum. Selective expression of α‐synuclein may relate to the neurotransmitter system utilized and predispose cholinergic enteric neurons to degeneration in Parkinson's disease. J. Comp. Neurol. 521:2523–2537, 2013. © 2013 Wiley Periodicals, Inc.
Ditopic Arginine‐Aspartate Binders Recognize RGD Loops
Authors: Gersthagen Thomas , Hofmann Johannes , Klärner Frank‐Gerrit , Schmuck Carsten , Schrader Thomas 
Published: January 2013

AbstractA synthetic strategy was developed for the construction of unsymmetrical arginine tweezers with an additional carboxylate binding site. The ditopic receptor molecules 2 and 3 use two arms to bind arginine–glycine–aspartate (RGD) peptides. However, contrary to expectations from molecular mechanics simulations, the tweezer cavity remains empty, and arginine is bound through a simple guanidinium/phosphate ion‐pair formation. On the other hand, carboxylate recognition by the guanidiniopyrrole moiety operates very efficiently, leading to complexation of ionic amino acids in both linear and cyclic RGD peptides with concentrations in the low micromolar range in a buffered aqueous solution (Kd = 20–30 μM). Truncation of the whole guanidiniopyrrole arm leads to the simple unsymmetrical monophosphate tweezer 1, which lacks the aspartate binder, but restores the arginine inclusion. Tweezer 1 displays a remarkable affinity and selectivity towards cyclic RGD peptides, presumably by a combination of arginine inclusion and additional cooperative hydrogen bonds between its phenolic OH group and the peptide backbone (NMR evidence, Kd = 15–30 μM). Comparison with symmetrical diphosphate tweezers 1a and 2–4 shows that in unsymmetrical tweezers the spacer group must guarantee an open cavity.
Effect of major cations (Ca2+, Mg2+, Na+, K+) and anions (SO 42−, Cl−, NO 3−) on Ni accumulation and toxicity in aquatic plant (Lemna minor L.): Implications For Ni risk assessment
Authors: Gopalapillai Yamini , Hale Beverley , Vigneault Bernard 
Published: January 2013

Abstract
The effect of major cation activity (Ca2+, Mg2+, Na+, K+) on Ni toxicity, with dose expressed as exposure (total dissolved Ni concentration NiTot) or free Ni ion activity (in solution Ni2+), or as tissue residue (Ni concentration in plant tissue NiTiss) to the aquatic plant Lemna minor L. was examined. In addition, Ni accumulation kinetics was explored to provide mechanistic insight into current approaches of toxicity modeling, such as the tissue residue approach and the biotic ligand model (BLM), and the implications for plant Ni risk assessment. Major cations did not inhibit Ni accumulation via competitive inhibition as expected by the BLM framework. For example, Ca2+ and Mg2+ (sulfate as counter-anion) had an anticompetitive effect on Ni accumulation, suggesting that Ca or Mg forms a ternary complex with Ni–biotic ligand. The counter-anion of the added Ca (sulfate, chloride, or nitrate) affected plant response (percentage of root growth inhibition) to Ni. Generally, sulfate and chloride influenced plant response while nitrate did not, even when compared within the same range of Ca2+, which suggests that the anion dominated the observed plant response. Overall, although an effect of major cations on Ni toxicity to L. minor L. was observed at a physiological level, Ni2+ or NiTot alone modeled plant response, generally within a span of twofold, over a wide range of water chemistry. Thus, consideration of major cation competition for improving Ni toxicity predictions in risk assessment for aquatic plants may not be necessary. Environ. Toxicol. Chem. 2013;32:810–821. © 2013 SETAC
Validation of the Brazilian version of the Apathy Inventory
Authors: Stella Florindo , de Andrade Larissa Pires , Garuffi Marcelo , Vital Thays Martins , Hernández Salma Stephany Soleman , Ruocco Marcela , Sé Elisandra Villela Gasparetto , Klein Margarete , Martins Tânia , Robert Philippe H. 
Published: January 2013

BackgroundApathy is a frequent neuropsychiatric condition in neurodegenerative disorders, depression, and often in mild cognitive impairment. The Apathy Inventory (AI) is a reliable instrument for improving the accuracy of the apathy diagnosis. The aim was to establish the validity of the Apathy Inventory for the Brazilian community.MethodsWe established the concurrent validity, internal consistency, inter‐rater reliability, and the sensitivity and specificity of AI for the Brazilian community in a cohort of 175 individuals with Alzheimer's disease, Parkinson's disease, depression, mild cognitive impairment, and healthy controls. The three dimensions of the AI (emotional blunting, lack of initiative, and lack of interest) were compared with the Apathy domain of the Neuropsychiatric Inventory‐Clinician rating scale (NPI‐C) in an independent scheme.ResultsThe analyses demonstrated high correlation coefficients in AI's individual dimensions and in AI‐total score (F = 0.965). Concerning the NPI‐C/Apathy domain, intra‐class correlation coefficients were also high (F = 0.977). Concurrent validity was high according to both raters on AI dimensions × NPI‐C/Apathy domain and regarding total score (rater 1: rho = 0.956 vs. rater 2: rho = 0.970). The internal consistency of the AI was also high concerning the AI's individual dimensions and total score (rater 1: 0.945 vs. rater 2: 0.958).ConclusionWe observed high internal consistency, high concurrent validity, and inter‐rater reliability of the Apathy Inventory. In addition, we found that its sensitivity and specificity were high. We suggest that the Brazilian version of the Apathy Inventory would be an appropriate instrument to identify the apathy syndrome in Brazilian patients. Copyright © 2013 John Wiley & Sons, Ltd.
The neuroprotective role of endocannabinoids against chemical‐induced injury and other adverse effects
Authors: Zogopoulos Panagiotis , Vasileiou Ioanna , Patsouris Efstratios , Theocharis Stamatios 
Published: January 2013

ABSTRACTConsiderable progress has been made, recently, in understanding the role of the endocannabinoid system in regard to neuroprotection. Endogenous cannabinoids have received increasing attention as potential protective agents in several cases of neuronal injury. The endocannabinoid system is comprised of cannabinoid receptors (CB1 and CB2), their endogenous ligands (endocannabinoids) and proteins responsible for their metabolism. Endocannabinoids serve as retrograde signalling messengers in GABAergic and glutamatergic synapses, as well as modulators of post‐synaptic transmission, interacting with other neurotransmitters, including norepinephrine and dopamine. Furthermore, endocannabinoids modulate neuronal, glial and endothelial cell function and exert neuromodulatory, anti‐excitotoxic, anti‐inflammatory and vasodilatory effects. Physiological stimuli and pathological conditions lead to differential increases in brain endocannabinoids that regulate distinct biological functions. The purpose of this review is to present the available in vivo and in vitro experimental data, up to date, regarding the endocannabinoid system and its role in neuroprotection, as well as its possible therapeutic perspectives. Copyright © 2013 John Wiley & Sons, Ltd.
Cystatin C and risk of hip fractures in older women
Authors: Ensrud Kristine E , Parimi Neeta , Cauley Jane A , Ishani Areef , Slinin Yelena , Hillier Teresa A , Taylor Brent C , Steffes Michael , Cummings Steven R ,   for the Study of Osteoporotic Fractures (SOF)
Published: January 2013

ABSTRACT

To test the hypothesis that older women with higher cystatin C are at increased risk of hip fracture independent of traditional risk factors including hip bone mineral density (BMD), we performed a case-cohort analysis nested in a cohort of 4709 white women attending a Year 10 (1997–1998) examination of the Study of Osteoporotic Fractures that included a random sample of 1170 women and the first 300 women with incident hip fracture occurring after Year 10 examination. Serum cystatin C and creatinine were measured in Year 10 sera. In a model adjusted for age, clinical site, body mass index, and total hip BMD, higher cystatin C was associated with an increased risk of hip fracture (p for linear trend 0.008) with women in quartile 4 having a 1.9-fold higher risk (hazard ratio [HR] 1.91; 95% confidence interval [CI], 1.24–2.95) compared with those in quartile 1 (referent group). Further adjustment for additional risk factors only slightly attenuated the association; the risk for hip fracture was 1.7-fold higher (HR 1.74; 95% CI, 1.11–2.72) in women in quartile 4 compared with those in quartile 1. In contrast, neither serum creatinine nor creatinine-based estimated glomerular filtration rate (eGFRCr) were associated with risk of hip fracture. Older women with higher cystatin C, but not higher serum creatinine or lower eGFRCr, have an increased risk of hip fracture independent of traditional risk factors. These findings suggest that cystatin C may be a promising biomarker for identification of older adults at high risk of hip fracture.
Model incorporating the ITPA genotype identifies patients at high risk of anemia and treatment failure with pegylated‐interferon plus ribavirin therapy for chronic hepatitis C
Authors: Kurosaki Masayuki , Tanaka Yasuhito , Nishida Nao , Sakamoto Naoya , Enomoto Nobuyuki , Matsuura Kentaro , Asahina Yasuhiro , Nakagawa Mina , Watanabe Mamoru , Sakamoto Minoru , Maekawa Shinya , Tokunaga Katsushi , Mizokami Masashi , Izumi Namiki 
Published: January 2013

AbstractThis study aimed to develop a model for predicting anemia using the inosine triphosphatase (ITPA) genotype and to evaluate its relationship with treatment outcome. Patients with genotype 1b chronic hepatitis C (n = 446) treated with peg‐interferon alpha and ribavirin (RBV) for 48 weeks were genotyped for the ITPA (rs1127354) and IL28B (rs8099917) genes. Data mining analysis generated a predictive model for anemia (hemoglobin (Hb) concentration <10 g/dl); the CC genotype of ITPA, baseline Hb <14.0 g/dl, and low creatinine clearance (CLcr) were predictors of anemia. The incidence of anemia was highest in patients with Hb <14.0 g/dl and CLcr <90 ml/min (76%), followed by Hb <14.0 g/dl and ITPA CC (57%). Patients with Hb ≥14.0 g/dl and ITPA AA/CA had the lowest incidence of anemia (17%). Patients with two predictors (high‐risk) had a higher incidence of anemia than the others (64% vs. 28%, P < 0.0001). At baseline, the IL28B genotype was a predictor of a sustained virological response [adjusted odds ratio 9.88 (95% confidence interval 5.01–19.48), P < 0.0001]. In patients who achieved an early virological response, the IL28B genotype was not associated with a sustained virological response, while a high risk of anemia was a significant negative predictor of a sustained virological response [0.47 (0.24–0.91), P = 0.026]. For high‐risk patients with an early virological response, giving >80% of the planned RBV dose increased sustained virological responses by 24%. In conclusion, a predictive model incorporating the ITPA genotype could identify patients with a high risk of anemia and reduced probability of sustained virological response. J. Med. Virol. 85:449–458, 2013. © 2013 Wiley Periodicals, Inc.
Lack of association between hepatitis B virus pre‐S mutations and recurrence after surgical resection in hepatocellular carcinoma
Authors: Heo Nae‐Yun , Lee Han Chu , Park Yoon Kyung , Park Jang Won , Lim Young‐Suk , Kim Kang Mo , Shim Ju Hyun , Lee Young‐Joo 
Published: January 2013

AbstractPre‐S mutation of hepatitis B virus (HBV) is known to be a risk factor for hepatocarcinogenesis. A previous study suggested that pre‐S mutation(s) may associate with increased recurrence after surgical resection. In the present study, 64 patients with HBV‐related hepatocellular carcinoma (HCC) were categorized into two groups according to the presence or absence of pre‐S mutation(s). The clinicopathological variables of the two groups were analyzed to assess the relationship between pre‐S mutations and postoperative recurrence. Nineteen patients (29.7%) had pre‐S mutations;13 had a pre‐S deletion, three had a pre‐S2 start codon mutation, two patients had both a pre‐S deletion, and a pre‐S2 start codon mutation, and one patient had a pre‐S2 insertion. The two groups did not differ in terms of baseline clinicopathological parameters. Cirrhosis and satellite lesion(s) were predictive factors for postoperative recurrence and poor overall survival. Recurrence‐free survival (P = 0.320) and overall survival (P = 0.238) did not differ significantly when pre‐S mutations were present. In conclusion, this study did not find evidence supporting the notion that pre‐S mutation(s) are associated with postoperative recurrence after surgical resection. J. Med. Virol. 85:589–596, 2013. © 2013 Wiley Periodicals, Inc.
Sagittal fresh blood imaging with interleaved acquisition of systolic and diastolic data for improved robustness to motion
Authors: Atanasova Iliyana P. , Kim Daniel , Storey Pippa , Rosenkrantz Andrew B. , Lim Ruth P. , Lee Vivian S. 
Published: January 2013

AbstractPurpose:To improve robustness to patient motion of “fresh blood imaging” (FBI) for lower extremity noncontrast MR angiography.Methods:In FBI, two sets of three‐dimensional fast spin echo images are acquired at different cardiac phases and subtracted to generate bright‐blood angiograms. Routinely performed with a single coronal slab and sequential acquisition of systolic and diastolic data, FBI is prone to subtraction errors due to patient motion. In this preliminary feasibility study, FBI was implemented with two sagittal imaging slabs, and the systolic and diastolic acquisitions were interleaved to minimize sensitivity to motion. The proposed technique was evaluated in volunteers and patients.Results:In 10 volunteers, imaged while performing controlled movements, interleaved FBI demonstrated better tolerance to subject motion than sequential FBI. In one patient with peripheral arterial disease, interleaved FBI offered better depiction of collateral flow by reducing sensitivity to inadvertent motion.Conclusions:FBI with interleaved acquisition of diastolic and systolic data in two sagittal imaging slabs offers improved tolerance to patient motion. Magn Reson Med, 2013. © 2013 Wiley Periodicals, Inc.
Damping analysis of polyurethane/polyacrylate interpenetrating polymer network composites filled with graphite particles
Authors: Liu Meiju , Song Guojing , Yi Jin , Xu Yonggang 
Published: January 2013

AbstractThe graphite‐filled polyurethane/poly(methyl methacrylate‐butyl methacrylate) (PU/P(MMA‐BMA)) semi‐interpenetrating polymer networks (IPNs) were synthesized by sequential method. The influences of graphite particle content and size on the 60/40 PU/P(MMA‐BMA) IPNs were studied. The damping properties of IPN composites were evaluated by dynamic mechanical thermal analysis (DMA) and cantilever beam resonance methods. The mechanical performances were investigated using tensile and hardness devices. DMA results revealed that the incorporation of graphite particles improved damping properties of IPNs significantly. The 5% graphite‐filled IPN composite exhibited the widest temperature range and the highest loss factor (tan δ) when the test frequency was 1 Hz. As to the damping properties covering a wide frequency range from 1 to 3,000 Hz, the addition of graphite particles broadened the damping frequency range (Δf, where tan δ is above 0.3) and increased the tan δ value of IPNs. Among them, the composite with 7.5% graphite showed the best damping capacity. And the hardness and the tensile strength of IPN composites were also improved significantly. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers