bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular evolution of 5′ flanking regions of 87 candidate genes for atherosclerotic cardiovascular disease
Authors: Ding Keyue , Kullo Iftikhar J. 
Published: June 2006

AbstractInter‐individual variation in quantitative traits as well as in disease susceptibility may be due to differences in the level and spatio‐temporal pattern of gene expression. An evolutionary model of genetic variation in cis‐regulatory regions may help identify loci of interest for the study of the genetic basis of complex diseases such as atherosclerotic cardiovascular disease (ASCVD). We studied the molecular evolution of 87 candidate genes for ASCVD to detect signatures of selection in 5′ flanking regions. Resequenced data for these genes were available in 24 African‐Americans, 23 European‐Americans, and 1 chimpanzee (Pan troglodytes). Statistical tests of evolutionary neutrality (Tajima's D and Fay and Wu's H) were performed using coalescent simulations under a standard neutral model and a population structure model to differentiate selection from human demographic history. Evidence suggestive of selection was present in 5′ flanking regions of 15 genes. A modified McDonald‐Kreitman test was used to compare the ratio of putative functional and non‐functional sites between and within species in 5′ flanking regions. A significant excess or deficit of fixed changes over polymorphisms was noted in 16 genes. Of the 26 genes showing deviation from evolutionary neutrality based on the above two tests, 13 genes showed an unusual haplotype pattern in 5′ flanking regions, providing supportive evidence of selection. These results indicate that selection may play a role in establishing variation in 5′ flanking regions of a subset of candidate genes for ASCVD and motivate further studies of these loci in determining inter‐individual susceptibility to ASCVD. Genet. Epidemiol. 2006. © 2006 Wiley‐Liss, Inc.
Subtle myelin defects in PLP‐null mice
Authors: Rosenbluth Jack , Nave Klaus‐Armin , Mierzwa Amanda , Schiff Rolf 
Published: June 2006

AbstractThis study explores subtle defects in the myelin of proteolipid protein (PLP)‐null mice that could potentially underlie the functional losses and axon damage known to occur in this mutant and in myelin diseases including multiple sclerosis. We have compared PLP‐null central nervous system (CNS) myelin with normal myelin using ultrastructural methods designed to emphasize fine differences. In the PLP‐null CNS, axons large enough to be myelinated often lack myelin entirely or are surrounded by abnormally thin sheaths. Short stretches of cytoplasm persist in many myelin lamellae. Most strikingly, compaction is incomplete in this mutant as shown by the widespread presence of patent interlamellar spaces of variable width that can be labeled with ferricyanide, acting as an aqueous extracellular tracer. In thinly myelinated fibers, interlamellar spaces are filled across the full width of the sheaths. In thick myelin sheaths, they appear filled irregularly but diffusely. These patent spaces constitute a spiral pathway through which ions and other extracellular agents may penetrate gradually, possibly contributing to the axon damage known to occur in this mutant, especially in thinly myelinated fibers, where the spiral path length is shortest and most consistently labeled. We show also that the “radial component” of myelin is distorted in the mutant (“diagonal component”), extending across the sheaths at 45° instead of 90°. These observations indicate a direct or indirect role for PLP in maintaining myelin compaction along the external surfaces of the lamellae and to a limited extent, along the cytoplasmic surfaces as well and also in maintaining the normal alignment of the radial component. © 2006 Wiley‐Liss, Inc.
Lack of chemokine receptor CCR5 promotes murine fulminant liver failure
Authors: Tiegs Gisa 
Published: June 2006

Abstract

Fulminant liver failure (FLF) consists of a cascade of events beginning with a presumed uncontrolled systemic activation of the immune system. The etiology of FLF remains undefined. In this study, we demonstrate that CCR5 deficiency promotes the development of acute FLF in mice following Con A administration by preventing activated hepatic CD1d-restricted NKT cells (but not conventional T cells) from dying from activation-induced apoptosis. The resistance of CCR5-deficient NKT cells from activation-induced apoptosis following Con A administration is not due to a defective Fas-driven death pathway. Moreover, FLF in CCR5-deficient mice also correlated with hepatic CCR5-deficient NKT cells, producing more IL-4, but not IFN-γ, relative to wild-type NKT cells. Furthermore, FLF in these mice was abolished by IL-4 mAb or NK1.1 mAb treatment. We propose that CCR5 deficiency may predispose individuals to the development of FLF by preventing hepatic NKT cell apoptosis and by regulating NKT cell function, establishing a novel role for CCR5 in the development of this catastrophic liver disease that is independent of leukocyte recruitment.
Studies towards a Conjugate Vaccine for Anthrax: Synthesis of the Tetrasaccharide Side Chain of the Bacillus anthracis Exosporium
Authors: Adamo Roberto , Saksena Rina , Kováč Pavol 
Published: June 2006

AbstractThe first synthesis of β‐L‐glycoside 17 of the tetrasaccharide β‐Ant‐(1 → 3)‐α‐L‐Rhap‐(1 → 3)‐α‐L‐Rhap‐(1 → 2)‐L‐Rhap is described (Schemes 1–3). Its spacer can be functionalized to make it amenable to conjugation to proteins by different conjugation methods. The synthesis was performed in a stepwise manner starting from the aglycon‐bearing terminal saccharide with thioglycosides as glycosyl donors. To attach the upstream terminal anthrose residue, the assembled linker‐equipped trisaccharide was glycosylated with ethyl 4‐azido‐3‐O‐benzyl‐2‐O‐(bromoacetyl)‐4,6‐dideoxy‐1‐thio‐β‐D‐glucopyranoside (11). Further functionalization of the tetrasaccharide thus obtained, followed by deprotection gave the target substance 17. Synthesis of substructures of 17 equipped with the same spacer, namely β‐L‐Rhap‐1‐O‐(CH2)5COOMe (21), α‐L‐Rhap‐(1 → 2)‐β‐L‐Rhap‐1‐O‐(CH2)5COOMe (22), and α‐L‐Rhap‐(1 → 3)‐α‐L‐Rhap‐(1 → 2)‐β‐L‐Rhap‐1‐O‐(CH2)5COOMe (23), is also described (Scheme 4).
Synthesis, Olfactory Evaluation, and Determination of the Absolute Configuration of the 3,4‐Didehydroionone Stereoisomers
Authors: Serra Stefano , Fuganti Claudio , Brenna Elisabetta 
Published: June 2006

AbstractThe synthesis of 3,4‐didehydroionone isomers 4, (+)‐6, and (−)‐6 and of 3,4‐didehydro‐7,8‐dihydroionone isomers 5, (+)‐7, and (−)‐7 was accomplished starting from commercially available racemic α‐ionone (1). Their preparation of the racemic forms 4–7 was first achieved by mean of a number of chemo‐ and regioselective reactions (Schemes 1 and 2). The enantio‐ and diastereoselective lipase‐mediated kinetic acetylation of 4‐hydroxy‐γ‐ionone (10a/10b) provided 4‐hydroxy‐γ‐ionone (+)‐10a/(±)‐10b and (+)‐4‐(acetyloxy)‐γ‐ionone ((+)12b) (Scheme 3). The latter compounds were used as starting materials to prepare the 3,4‐didehydro‐γ‐ionones (+)‐ and (−)‐6 and the 3,4‐didehydro‐7,8‐dihydro‐γ‐ionones (+)‐ and (−)‐7 in enantiomer‐enriched form. The absolute configuration of (+)‐12b was determine by chemical correlation with (+)‐(6S)‐γ‐ionone ((+)‐3) and with (−)‐(6S)‐α‐ionone ((−)‐1) therefore allowing to assign the (S)‐configuration to (+)‐6 and (+)‐7. Olfactory evaluation of the above described 3,4‐didehydroionone isomers shows a significant difference between the enantiomers and regioisomers both in fragrance feature and in detection threshold (Table).
Synthesis and Electronic Spectroscopy of Bromocarbazoles. Direct Bromination of N‐ and C‐Substituted Carbazoles by N‐Bromosuccinimide or a N‐Bromosuccinimide/Silica Gel System
Authors: Ponce María B. , Cabrerizo Franco M. , Bonesi Sergio M. , Erra‐Balsells Rosa 
Published: June 2006

AbstractThe preparation, isolation and characterization by elemental analysis and 1H‐NMR, 13C‐NMR, and MS data of the bromo derivatives of N‐substituted carbazoles, i.e., of 9‐methyl‐9H‐carbazole (1), 9‐phenyl‐9H‐carbazole (2), 9‐benzyl‐9H‐carbazole (3), 2‐methoxy‐9‐methyl‐9H‐carbazole (4), and of C‐substituted carbazoles, i.e., of 2‐(acetyloxy)‐9H‐carbazole (5) and 3‐nitro‐9H‐carbazole (6), are reported, in part for the first time. As brominating reagents, N‐bromosuccinimide (NBS) or NBS/silica gel in CH2Cl2, NBS in AcOH, KBrO3/KBr in EtOH doped with a catalytic amount of H2SO4, or KBrO3/KBr in AcOH were employed, and their uses were compared. Semi‐empirical PM3 calculations were performed to predict the reactivity of the N‐substituted and C‐substituted carbazoles and of their bromo derivatives and found to verify the experimental results. The UV‐absorption and fluorescence and phosphorescence emission spectra of the bromocarbazole derivatives in MeCN solution at 298 K and in a solid matrix at 77 K were compared with those of the corresponding carbazoles 1–6. The dynamic properties of the lowest excited singlet and triplet states (τf, τp, ϕf, and ϕp) were measured under the same experimental conditions. The intramolecular spin–orbital‐coupling effect of the Br‐atom and NO2 group on the spectroscopic data, photophysical parameters, and on the photo reactivity were also briefly analyzed.
A New Synthesis of Pteridines
Authors: Xu Ming , Vasella Andrea 
Published: June 2006

AbstractA new synthesis of pteridines possessing a (substituted) (Z)‐3‐hydroxyprop‐1‐enyl group at C(6) is based on the acylation of 4‐amino‐5‐nitrosopyrimidines with dienoic acid chlorides, followed by a high‐yielding intramolecular hetero‐Diels–Alder cycloaddition and cleavage of the NO bond leading to 4. Thermolysis of the resulting pteridines 4 possessing a benzyloxy group at C(4) led to the products 5, resulting from isomerisation of the 3‐hydroxyprop‐1‐enyl to an 3‐oxopropyl side chain, while the analogous pteridine 8 possessing an NH2 group at C(4) remained unaffected.
Three Novel Terpenoids from Schisandra pubescens var. pubinervis
Authors: Huang Sheng‐Xiong , Yang Jing , Xiao Wei‐Lie , Zhu Yan‐Ling , Li Rong‐Tao , Li Li‐Mei , Pu Jian‐Xin , Li Xian , Li Sheng‐Hong , Sun Han‐Dong 
Published: June 2006

AbstractThree new terpenoids, pubinernoids A–C (1–3), together with six known sesquiterpenoids, were isolated from the leaves and stems of Schisandra pubescens var. pubinervis. The structures of the new compounds were established on the basis of extensive spectroscopic analyses, including application of 2D‐NMR spectroscopic techniques. A plausible formation of the sesquiterpenoid 2 is proposed (Scheme 2), starting from guaianediol (4) as the biogenetic precursor, which was also present in the extract.
Structure Elucidation of Two New Diterpenoids from Isodon phyllostachys: Phyllostacins A and B
Authors: Li Xian , Xiao Wei‐Lie , Huang Sheng‐Xiong , Weng Zhi‐Ying , Shen Yun‐Heng , Han Quan‐Bin , Sun Han‐Dong 
Published: June 2006

AbstractTwo new ent‐kaurane‐derived diterpene derivatives, phyllostacins A (1) and B (2), were isolated from the aerial parts of Isodon phyllostachys, together with two known compounds, irroratin A (3) and serrin B (4). Both 1 and 2 were found to be present as diastereoisomers. In the case of 1, the corresponding diastereoisomeric diacetates 5 and 6 were prepared and separated. The structures of the new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods, in combination with MS experiments. In (D5)pyridine solution, the two epimers of 1 are present in equal amounts, but in CDCl3 or CD3OD, the (S)‐epimer predominates in the mixture of hemiacetals.
New, Diastereoselective One‐Pot Synthesis of Tetrasubstituted Hydantoins
Authors: Alizadeh Abdolali , Masrouri Hassan 
Published: June 2006

AbstractAn effective route to hydantoins is described, based on the 2 : 1 : 1 addition of arylsulfonyl isocyanates, dialkyl acetylenedicarboxylates, and dialkyl trialkylsilyl phosphites. The resulting tetrasubstituted, stable hydantoins 4/4′ (Table) were obtained in excellent yields, and their structures were corroborated spectroscopically (IR, 1H‐, 13C‐, 31P‐NMR, EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 2).
Synthesis and Characterization of Polypiridine‐Based Rhenium(I) Complexes with Pyrazino[2,3‐f][1,10]phenanthroline
Authors: Díaz Ramiro , Francois Angélica , Leiva Ana María , Loeb Bárbara , Norambuena Ester , Yañez Mauricio 
Published: June 2006

AbstractA series of tricarbonyl rhenium(I) complexes of the type fac‐[ReI(CO)3(ppl)(L)]0/+, where ppl is pyrazino[2,3‐f][1,10]phenanthroline, and where L is Cl−, TfO−, 4‐(tert‐butyl)pyridine (tBu‐py), 4‐methoxypyridine (MeO‐py), 4,4′‐bipyridyl (bpy), or 10‐(picolin‐4‐yl)phenothiazine (pptz), were synthesized and fully characterized. In all complexes, an increment in the electron‐acceptor properties of ppl compared to the free ligand was observed. This effect was more significant for pyridine‐type ligands, especially for pptz, compared to Cl− or TfO−. The properties of fac‐[Re(CO)3(ppl)(pptz)]PF6 were compared with those of the analogous compound fac‐[Re(CO)3(dppz)(pptz)]PF6, where dppz is dipyrido(3,2‐a : 2′,3′‐c)phenazine, the goal being to generate long‐lived excited charge‐transfer (CT) states. In this respect, fac‐[Re(CO)3(ppl)(pptz)]PF6 seems to be a promising candidate.
Synthesis of Highly Functionalized γ‐Lactones via 1,5‐Electrocyclic Ring Closure
Authors: Anaç Olcay , Güngör F. Şeyma , Merey Gökçe 
Published: June 2006

AbstractWe have investigated 1,5‐electrocyclic ring‐closure reactions of conjugated esters with dimethyl diazomalonate in the presence of [Cu(acac)2] as catalyst. Our new protocol offers an easy entry to various polyfunctionalized γ‐lactones in high yields. Their subsequent derivatives may be used as valuable intermediates, especially in the synthesis of natural products and their analogues.
An Expeditious Synthesis of Methyl Jasmonate
Authors: Chapuis Christian , Cantatore Carole , de Saint Laumer Jean‐Yves 
Published: June 2006

AbstractWe present an efficient three‐step, two‐pot synthesis of methyl jasmonate (trans‐1) based on Diels–Alder cycloaddition of cyclopent‐2‐enone (2) and chloroprene (= 2‐chlorobuta‐1,3‐diene; 3d) in either CHCl3 or CH2Cl2, catalyzed by SnCl4 (0.2 mol‐equiv.) at 20° (75% yield). Subsequent ozonolysis of a cis/trans 55 : 45 mixture of the cycloadduct 4d in either CH2Cl2 or AcOEt at − 78°, followed by addition of Me2S and MeOH in the presence of NaHCO3, afforded, in 64% yield, a cis/trans 40 : 60 mixture of the known aldehyde 5c. The latter was reacted at − 50° under salt‐free conditions with the propyl Wittig reactant to furnish 1 as a cis/trans 20 : 80 mixture ((E/Z) 3 : 97). Alternatively, a cis/trans 7 : 93 mixture ((E/Z) 4 : 96) was obtained in 88% yield from epimerized 5c (AcOH, H2O, 40°; 99%) under usual Wittig conditions at − 20°.
Intrauterine environment and breast cancer risk in a population‐based case‐control study in Poland
Authors: Park Sue Kyung , Garcia‐Closas Montserrat , Lissowska Jolanta , Sherman Mark E. , McGlynn Katherine A. , Pepońska Beata , Bardin‐Mikoajczak Alicja , Zatoński Witold , Szeszenia‐Dąbrowska Neonila , Brinton Louise A. 
Published: June 2006

AbstractHigh estrogen exposure in utero may increase breast cancer risk later in life. However, studies of the associations between perinatal factors presumed to affect the fetal hormonal environment and breast cancer risk are inconsistent. We used data from a population‐based case‐control study of 2,386 incident breast cancers and 2,502 controls in Poland to evaluate risks associated with various perinatal characteristics. After adjusting for confounders, we found a significant trend (p = 0.01) of breast cancer risk with birth weight (OR = 1.54, 95% CI 1.08–2.19 for birth weights >4,000 g vs. <2,500 g). Subjects with a high birth order (≥6) were at reduced risk (OR = 0.81, 0.61–1.06) when compared with first born subjects. Birth weight was somewhat a stronger risk predictor among subjects whose cancers were diagnosed at 50 years of age or older (OR = 1.84, 1.19–2.85) than among those with cancers diagnosed at younger ages (OR = 1.14, 0.61–2.12). Subjects whose mothers smoked during their pregnancies were at slightly higher risk than those who never smoked (OR = 1.21, 0.99–1.47), but the risk was similar to mothers who only smoked at other times (OR = 1.22, 0.81–1.84). Breast cancer risk was not related to paternal smoking, maternal age, gestational age or twin status. Our results add support to the growing evidence that some perinatal exposures may relate to breast cancer risk. Additional studies are needed to confirm associations and clarify the biologic mechanisms underlying these associations. Published 2006 Wiley‐Liss, Inc.
Structure and function of the components of the human DNA mismatch repair system
Authors: Jascur Thomas , Boland C. Richard 
Published: June 2006

AbstractDNA mismatch repair (MMR) is one of the several enzyme systems involved in DNA homeostasis. DNA MMR is involved in the repair of specific types of errors that occur during new DNA synthesis; loss of this system leads to an accelerated accumulation of potential mutations, and predisposes to certain types of cancers. Germline mutations in some of the DNA MMR genes cause the hereditary cancer predisposition, Lynch syndrome. This review addresses advances in the biochemistry of DNA MMR and its relationship to carcinogenesis. © 2006 Wiley‐Liss, Inc.
Severe oxidatively damaged DNA after cisplatin treatment of cancer patients
Authors: Siomek Agnieszka , Tujakowski Jerzy , Gackowski Daniel , Rozalski Rafal , Foksinski Marek , Dziaman Tomasz , Roszkowski Krzysztof , Olinski Ryszard 
Published: June 2006

AbstractThere is growing evidence suggesting that cytotoxic activity of cisplatin is closely associated with increased generation of reactive oxygen species (ROS). Therefore, this study was undertaken to examine oxidative DNA damage, which arises as a result of chemotherapy with cisplatin. Using HPLC prepurification/isotope dilution GC/MS methodology, we examined the amount of 8‐oxoGua and 8‐oxodG excreted into urine in cancer patients (n = 66) who received chemotherapy with cisplatin. One day after the infusion of the drug, significant increase in the amount of 8‐oxoGua and 8‐oxodG in urine of the patients was observed, when compared to the initial value (78%, p < 0.0001 and 22%, p = 0.0051). In the “nadir days” (when the most distinct cell death based on hematological cell counts can be observed), the level of modified base and nucleoside decreased in comparison with the aforementioned time point. These results, for the first time, indicate that oxidatively damaged DNA may be, at least in part, responsible for cisplatin induced cytotoxicity. Our results also demonstrate that cell death does not contribute to urinary 8‐oxoGua and 8‐oxodG in humans. © 2006 Wiley‐Liss, Inc.
Variant genotypes of CDKN1A and CDKN1B are associated with an increased risk of breast cancer in Chinese women
Authors: Ma Hongxia , Jin Guangfu , Hu Zhibin , Zhai Xiangjun , Chen Wensen , Wang Shui , Wang Xuechen , Qin Jianwei , Gao Jun , Liu Jiyong , Wang Xinru , Wei Qingyi , Shen Hongbing 
Published: June 2006

Abstractp21Cip1 and p27Kip1 are cyclin‐dependent kinase inhibitors, which can arrest cell proliferation and serve as tumor suppressors. Reduced protein expression of p21Cip1 and p27Kip1 was frequently observed in a subset of cancers, including breast cancer. In this study, we hypothesized that genetic variants in CDKN1A (encode for p21Cip1) and CDKN1B (encode for p27Kip1) may modulate the risk of breast cancer. To test this hypothesis, we evaluated the associations of the polymorphisms of Ser31Arg and C+20T in CDKN1A and C−79T and Gly109Val in CDKN1B, as well as their combinations, with breast cancer risk in a case‐control study of 368 breast cancer cases and 467 cancer‐free controls in a Chinese population. We found that a significantly increased risk of breast cancer was associated with the variant genotypes of CDKN1B C−79T [adjusted OR = 1.43 (95% CI = 1.03−1.98) for −79TC/TT], compared with the −79CC genotype, but no associations were observed for other variant genotypes. However, the combined variant genotypes of the 4 loci were associated with a significantly increased breast cancer risk (adjusted OR = 1.49, 95% CI = 1.11−2.01 among subjects carrying 3 or more variant alleles), especially among premenopausal women (adjusted OR= 2.30, 95% CI = 1.45−3.66). Furthermore, in premenopausal women, this significant association remained unchanged, after including other individual risk factors in the multivariate logistic regression model, suggesting an independent role of CDKN1A and CDKN1B variants in breast cancer risk. Although the exact biological mechanism remains to be explored, our findings suggest possible involvement of CDKN1A and CDKN1B variants in the etiology of breast cancer. Further large and functional studies are needed to confirm our findings. © 2006 Wiley‐Liss, Inc.
High‐resolution imaging of the intracranial arterial and venous systems following a single contrast injection
Authors: Al‐Kwifi Osama , Shelef Ilan , Farb Richard I. , Stainsby Jeffrey , Wright Graham A. 
Published: June 2006

AbstractPurposeTo generate two separate three‐dimensional (3D) high spatial resolution images of the intracranial arterial and venous systems using a single contrast injection.Materials and MethodsA 3D contrast‐enhanced (CE) magnetic resonance angiography (MRA) acquisition was modified to create two separate k‐space data sets to encode the arterial and venous enhancement signals individually after contrast agent injection. Following an automated detection of contrast arrival, the central k‐space views corresponding to the arterial phase were acquired for the first eight seconds. A full elliptical‐centric acquisition was then acquired for the venous phase and the missing views in the periphery of the first k‐space data set were copied from the venous phase. A total of 18 patients underwent this study. Image quality, signal‐to‐noise ratio (SNR), and contrast‐to‐noise ratio (CNR) were determined in both intracranial systems.ResultsTwo 3D image sets were generated for the arterial and venous intracranial systems. Both sets have high quality images that are clinically diagnostic. SNR and CNR were high in both sets, so that all the major vessels were visible.ConclusionThis technique provides images with high spatial resolution for both arterial and venous intracranial systems using a single contrast injection. J. Magn. Reson. Imaging 2006;9999:000–000. © 2006 Wiley‐Liss, Inc.
Modulations of VEGF and iNOS in the rat heart by low level laser therapy are associated with cardioprotection and enhanced angiogenesis
Authors: Tuby Hana , Maltz Lidya , Oron Uri 
Published: June 2006

AbstractBackground and ObjectivesIt has been shown previously that low‐level laser therapy (LLLT) significantly reduces infarct size following induction of myocardial infarction in rats and dogs. The aim of the present study was to investigate the effect of LLLT on the expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS).Study Design and Material and MethodsMyocardial infarction was induced by occlusion of the left descending artery in 87 rats. LLLT was applied to intact and post‐infarction. VEGF, iNOS, and angiogenesis were determined.ResultsBoth the laser‐irradiated rat hearts post‐infarction and intact hearts demonstrated a significant increase in VEGF and iNOS expression compared to non‐laser‐irradiated hearts. LLLT also caused a significant elevation in angiogenesis.ConclusionsIt is concluded that VEGF and iNOS expression in the infarcted rat heart is markedly upregulated by LLLT and is associated with enhanced angiogenesis and cardioprotection. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.