bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is there a hormonal network in Tetrahymena? A systematic investigation of hormonal effects on the hormone content
Authors: Csaba G. , Pállinger Éva 
Published: October 2007

AbstractThe effect of six hormones (histamine, serotonin, insulin, epidermal growth factor (EGF), oxytocin and gonadotropin) was studied on the hormone (histamine, serotonin, adrenocorticotropic hormone [ACTH], endorphin and triiodothyronine [T3]) content of Tetrahymena. The hormones were given in 10−9 or 10−12 M concentrations or as 0.1 and 0.001 I.U. ml−1 (in the case of oxytocin and gonadotropin) for 1 h. The hormones in picomolar concentration, i.e. at levels which can be present also in natural conditions, influence the amount of other hormones inside the cell. Their effect is not a general one: it is individual, the level of one of the hormones was elevated, while that of the others diminished under the effect of the same hormonal stimulus. Insulin was the only hormone, which influenced the concentration of other hormones in one direction, elevating them. This effect could have a role in the life‐saving property of this hormone in Tetrahymena, but the hormones were not studied from this point of view. Usually there is no difference between the effect of the two concentrations used, but there are situations when the effect of the two concentrations is opposite. This means that there is a possible concentration dependence and this could influence differently the cells which are far from or near to the secretor cell. Considering earlier observations, the duration of the treatment can also influence the result. The results give new data to the hormonal regulation at unicellular level (which can be the base of regulation at higher evolutionary levels) and point to the possibility of a hormonal network. Copyright © 2007 John Wiley & Sons, Ltd.
Detection of a Pathway From Linoleate to a Novel Cyclopentenone: cis‐12‐Oxo‐10‐Phytoenoic Acid in Sunflower Roots
Authors: Grechkin Alexander N. , Ogorodnikova Anna V. , Gnezdilov Oleg I. , Mukhtarova Lucia S. 
Published: October 2007

AbstractThe lipoxygenase pathway in sunflower roots was studied in vitro. A preliminary incubation of linoleic acid with 15 000 g supernatant of homogenate of sunflower roots (1.5–6 days after germination) revealed the predominant activity of 13‐lipoxygenase. The exogenously added linoleic acid 13‐hydroperoxide is further utilized through two competing pathways. One of them is directed towards formation of the ketodiene (9Z,11E)‐13‐oxooctadeca‐9,11‐dienoic acid. The second pathway, which is controlled by allene oxide synthase, leads to the formation of an α‐ketol and a novel cyclopentenone, rac‐cis‐12‐oxo‐10‐phytoenoic acid (12‐oxo‐PEA) via a short‐lived allene oxide. Unexpectedly, the cyclopentenone 12‐oxo‐PEA is the predominant allene oxide synthase product. Identification of cis‐12‐oxo‐PEA was confirmed by its UV, mass, 1H NMR and 2D‐COSY spectral data. The highest yield of 12‐oxo‐PEA is observed in very young roots (1.5–2 days after germination). The results of methanol‐trapping experiments demonstrate that both 12‐oxo‐PEA and α‐ketol are formed through the unstable allene oxide intermediate, (9Z)‐12,13‐epoxyoctadeca‐9,11‐dienoic acid, which is the primary product of allene oxide synthase. Since 12‐oxo‐PEA is a jasmonate congener, its biosynthesis in plants might be of physiological importance.
Antibody Labeling of Cholesterol/Ceramide Ordered Domains in Cell Membranes
Authors: Scheffer Luana , Futerman Anthony H. , Addadi Lia 
Published: October 2007

AbstractA monoclonal antibody raised against mixed monolayers of 60:40 mol % cholesterol/C16‐ceramide of known structure was used to label cholesterol/ceramide‐rich domains in cell membranes. The antibody, Cer–Chol 405F specifically recognizes the mixed crystalline and homogeneous phase in monolayers, but it does not interact with either of the components separately. It interacts differently with mixed monolayers that contain ceramides of different acyl chain length. When used on cells, the antibody labeling is sensitive to changes in cholesterol and ceramide levels, as well as to over‐expression of specific ceramides; this is in agreement with the results that were obtained on lipid monolayers. This represents a proof of concept of the applicability of a new approach to the structural characterization of lipid microdomains in cell membranes. The approach consists of raising antibodies that recognize specific structural organizations of lipids in artificial mixtures, characterizing the antibody/ordered domain complexes in vitro, and subsequently using them to detect the presence of the same (or similar) domains in cell membranes.
In Situ Synthesis of Gold and Silver Nanoparticles by Using Redox‐Active Amphiphiles and Their Phase Transfer to Organic Solvents
Authors: Si Satyabrata , Dinda Enakshi , Mandal Tarun K. 
Published: October 2007

AbstractAn in situ reduction approach to synthesizing gold and silver nanoparticles by using a series of newly designed, redox‐active amphiphiles at basic pH is described. These amphiphiles are the conjugates of a fatty acid (e.g., oleic acid, stearic acid, and lauric acid) and a redox‐active amino acid (e.g., tryptophan or tyrosine). The amphiphile‐coated nanoparticles are then efficiently transferred from water to different nonpolar organic media (such as benzene, toluene, xylene, cyclohexane, and hexane) simply by acid treatment. The phase‐transfer process was monitored by UV/visible spectroscopy and transmission electron microscopy, and the results showed that the average particle size and size distribution remain almost unchanged after transferring to the organic media. The anchoring of the amphiphile to the nanoparticle surface was confirmed by FTIR spectroscopy and thermogravimetric analysis. A mechanism is proposed to describe the stability of colloidal Au and Ag nanoparticles formed in situ and their phase transfer to organic solvents. The presence of the amphiphile increases the thermal stability of the colloidal gold nanoparticle conjugates in organic solvents.
A Nanoporous Reactor for Efficient Proteolysis
Authors: Qiao Liang , Liu Yun , Hudson Sarah P. , Yang Pengyuan , Magner Edmond , Liu Baohong 
Published: October 2007

AbstractA nanoreactor based on mesoporous silicates is described for efficient tryptic digestion of proteins within the mesochannels. Cyano‐functionalized mesoporous silicate (CNS), with an average pore diameter of 18 nm, is a good support for trypsin, with rapid in situ digestion of the model proteins, cytochrome c and myoglobin. The generated peptides were analyzed by matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Proteolysis by trypsin‐CNS is much more efficient than in‐solution digestion, which can be attributed to nanoscopic confinement and concentration enrichment of the substrate within the mesopores. Proteins at concentrations of 2 ng μL−1 were successfully identified after digestion for 20 min. A biological complex sample extracted from the cytoplasm of human liver tissue was digested by using the CNS‐based reactor. Coupled with reverse‐phase HPLC and MALDI‐TOF MS/MS, 165 proteins were identified after standard protein data searching. This nanoreactor combines the advantages of short digestion time with retention of enzymatic activity, providing a promising way to advance the development of proteomics.
A Molecular Shuttle for Driving a Multilevel Fluorescence Switch
Authors: Zhou Weidong , Li Junbo , He Xiaorong , Li Cuihong , Lv Jing , Li Yuliang , Wang Shu , Liu Huibiao , Zhu Daoben 
Published: October 2007

AbstractA [2]rotaxane‐based molecular shuttle comprised a macrocycle mechanically interlocked to a chemical “dumbbell” has been prepared in high yields by a thermodynamically controlled, template‐induced clipping procedure. This molecular shuttle has two different recognition sites, namely, NH2+ and amide, separated by a phenyl unit. The macrocycle exhibits high selectivity for the NH2+ recognition sites in the protonated form through noncovalent interactions, which include 1) N+H⋅⋅⋅O hydrogen bonds; 2) CH⋅⋅⋅O interactions between the CH2NH2+CH2 protons on the thread and the oligo(ethylene glycol) unit in the macrocycle; 3) π⋅⋅⋅π stacking interaction between macrocycle and aromatic unit. Upon deprotonation of the [2]rotaxane the macrocycle glides to the amide recognition site due to the hydrogen bonds between the CONH group and the oligo(ethylene glycol) unit in the macrocycle. The deprotonation process requires about 10 equivalents of base (iPr2NEt) in polar acetone, while the amount of base is only 1.2 equivalents in apolar tetrachloroethane. Upon addition of Li+, the conformation of the [2]rotaxane was altered as a result of the collective interactions of 1) hydrogen bonds between pyridine nitrogen and amide hydrogen atoms; 2) coordination between the oligo(ethylene glycol) unit, amide oxygen atom and Li+ cation. Then, when Zn2+ ions are added, the macrocycle returns to the deprotonated NH recognition site owing to coordination of the macrocycle and NH from the axle with the Zn2+ ion. All the above‐mentioned movement processes are reversible through the alternate addition of TFA/iPr2NEt, Li/[12]‐crown‐4 and Zn2+/ethylenediaminetetraacetate (EDTA), by virtue of hydrogen bonding and metal‐ion complexation. Significantly, the three independent movement processes are all accompanied by fluorescent responses: 1) complete repression in the protonated form; 2) low‐level expression in the deprotonated form; 3) medium‐level expression following addition of Li+; 4) high‐level expression on complexation with Zn2+.
Low serum albumin level is associated with cytomegalovirus reactivation in patients with chronic lymphoproliferative diseases treated with alemtuzumab (Campath‐1H)‐based therapies
Authors: Borthakur Gautam , Lin E , Faderl Stefan , Ferrajoli Alessandra , Wierda William , Giles Francis , Browning Mary L. , Kantarjian Hagop , Keating Michael , O'Brien Susan 
Published: October 2007

AbstractBACKGROUND.Alemtuzumab (Campath‐1H), a monoclonal antibody that targets the CD52 antigen, has been approved for the treatment of fludarabine‐refractory chronic lymphocytic leukemia. However, the profound immunosuppression caused by alemtuzumab has been associated with infectious complications.METHODS.The authors report on the incidence and risk factors for development of symptomatic cytomegalovirus reactivation in 113 patients with chronic lymphoproliferative disorders who received alemtuzumab‐based therapy. Kaplan‐Meier methods were applied to generate survival curves, and the log‐rank test was used to assess the difference between groups; in addition, univariate and multivariate Cox proportional hazards models were used to estimate the hazard ratio of death including 95% confidence intervals.RESULTS.Cytomegalovirus reactivation was diagnosed in 25 patients (22%), and most of those patients responded to antiviral therapy. Nine additional patients had asymptomatic cytomegalovirus viremia.CONCLUSIONS.With appropriate therapy, most patients achieved clearance of cytomegalovirus viremia. Low serum albumin was the only factor associated significantly with symptomatic cytomegalovirus reactivation. Cancer 2007. © 2007 American Cancer Society.
Does androgen‐deprivation therapy accelerate the development of frailty in older men with prostate cancer?
Authors: Bylow Kathryn , Mohile Supriya G. , Stadler Walter M. , Dale William 
Published: October 2007

AbstractThe majority of men with prostate cancer are aged ≥65 years. Men, as they age, are more likely to suffer from impaired physical function. The standard treatment for recurrent prostate cancer is androgen‐deprivation therapy (ADT). Well‐established toxicities from ADT include lean weight loss or sarcopenia, muscle weakness, fatigue, and reduced activity levels. Frailty is a term from geriatrics that describes older individuals with limited physiologic reserve who are at significant risk for adverse outcomes, including falls, disability, hospitalization, and death. An increasingly accepted definition of frailty is a syndrome in which ≥3 of the following are present: unintentional (lean) weight loss ≥10 pounds in the past year, weakness (measured by grip strength), slow walking speed, self‐reported exhaustion, and low physical activity. This clinical syndrome overlaps closely with the known toxicities of ADT. In addition, alterations in the inflammatory system, neuroendocrine system, and energy production are associated with this syndrome, as evidenced by biomarkers such as C‐reactive protein, interleukin‐6, and tumor necrosis factor‐α. For this article, the authors reviewed the evidence for the effect of ADT on each of the 5 frailty components plus the identified biomarkers, and the evidence indicates that ADT may accelerate the development of frailty in vulnerable older men with prostate cancer. Given the association of frailty with important clinical outcomes such as hospitalization and death, this potential consequence of ADT should be considered carefully when initiating therapy in older patients with recurrent prostate cancer. Cancer 2007. © 2007 American Cancer Society.
Bevacizumab improves pathologic response and protects against hepatic injury in patients treated with oxaliplatin‐based chemotherapy for colorectal liver metastases
Authors: Ribero Dario , Wang Huamin , Donadon Matteo , Zorzi Daria , Thomas Melanie B. , Eng Cathy , Chang David Z. , Curley Steven A. , Abdalla Eddie K. , Ellis Lee M. , Vauthey Jean‐Nicolas 
Published: October 2007

AbstractBACKGROUND.The current study evaluated the effect of bevacizumab added to fluoropyrimidine‐plus‐oxaliplatin (5FU/OX) chemotherapy for colorectal liver metastases (CLM) on the pathologic response and nontumorous liver histology.METHODS.A total of 105 consecutive patients treated preoperatively with 5FU/OX chemotherapy with (n = 62) or without (n = 43) bevacizumab were analyzed. The response to chemotherapy was evaluated by pathologic analysis of tumor viability (percentage of viable tumor in relation to tumor surface area). The incidence and grade of hepatic sinusoidal dilation were also investigated.RESULTS.Bevacizumab‐containing regimens significantly reduced the degree of tumor viability compared with 5FU/OX‐only chemotherapy (32.9% vs 45.3%; P = .02). After stratification according to the magnitude of tumor viability, a higher proportion of patients treated with bevacizumab than without had <25% residual viable tumor cells (45% vs 23%; P = .02). However, the addition of bevacizumab to 5FU/OX did not appear to increase the incidence of complete pathologic response (11.3% vs 11.6%; P = .59). The incidence and severity of sinusoidal dilation was lower in patients treated with bevacizumab than in those treated with 5FU/OX only (any grade: 27.4% vs 53.5%; moderate or severe: 8.1% vs 27.9%; both P < .01).CONCLUSIONS.In patients treated with 5FU/OX chemotherapy, bevacizumab improves the pathologic response, as demonstrated by a reduction of the degree of tumor viability, and reduces the incidence and severity of hepatic injury. This retrospective study provides additional evidence supporting the use of bevacizumab in combination with 5FU/OX for CLM. Cancer 2007. © 2007 American Cancer Society.
A comprehensive analytical model of interconnection networks in large‐scale cluster systems
Authors: Javadi Bahman , Abawajy Jemal H. , Akbari Mohammad K. 
Published: October 2007

AbstractThe trends in parallel processing system design and deployment have been toward networked distributed systems such as cluster computing systems. Since the overall performance of such distributed systems often depends on the efficiency of their communication networks, performance analysis of the interconnection networks for such distributed systems is paramount. In this paper, we develop an analytical model, under non‐uniform traffic and in the presence of communication locality, for the m‐port n‐tree family interconnection networks commonly employed in large‐scale cluster computing systems. We use the proposed model to study two widely used interconnection networks flow control mechanism namely the wormhole and store&forward. The proposed analytical model is validated through comprehensive simulation. The results of the simulation demonstrated that the proposed model exhibits a good degree of accuracy for various system organizations and under different working conditions. Copyright © 2007 John Wiley & Sons, Ltd.
High input impedance voltage‐mode first‐order all‐pass sections
Authors: Maheshwari Sudhanshu 
Published: October 2007

AbstractThis paper proposes six new first‐order voltage‐mode all‐pass sections (VM‐APSs) based on three general topologies. Each circuit uses two differential voltage current conveyors and three grounded passive components. All the circuits possess high input impedance and easy control of pole frequency either by a simple matching of resistors (two equal‐valued resistors) for the three canonical circuits or by a single resistor for three non‐canonical circuits. PSPICE simulation results using real device 0.5µ CMOS parameters are given to validate the proposed circuits. Copyright © 2007 John Wiley & Sons, Ltd.
Cationic Gold(I) Phosphanyl Thiolates: Aurophilic Interactions in the Solid State and in Solution
Authors: Balzano Federica , Cuzzola Angela , Diversi Pietro , Ghiotto Fabio , Uccello‐Barretta Gloria 
Published: October 2007

AbstractThe aggregation states in solution of gold(I) cationic complexes of the formula [Au2(StBu)(L2)][BF4] (L = PMe3, PEt3, PtBu3, PPh3; L2 = dppm, dppe) were studied by MS (ESI) and DOSY spectroscopy. These compounds are tetranuclear in the solid state with a core of four gold centres bound together by aurophilic interactions and bridging thiolato groups. Some of these tetranuclear systems are maintained intact in solution depending on the phosphane steric properties or denticity.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The (Porphyrin)ruthenium‐Catalyzed Aziridination of Olefins Using Aryl Azides as Nitrogen Sources
Authors: Fantauzzi Simone , Gallo Emma , Caselli Alessandro , Piangiolino Cristiana , Ragaini Fabio , Cenini Sergio 
Published: October 2007

AbstractAryl azides have been used as atom‐efficient nitrene transfer reagents in the (porphyrin)ruthenium‐catalyzed amination of olefins. Several azides, olefins and [Ru(porphyrin)CO] complexes were tested to investigate the scope and limits of the reaction. Quantitative yields and short reaction times were achieved by using terminal olefins and aryl azides bearing electron‐withdrawing groups on the aryl moiety. The reactions were influenced by steric factors. Internally disubstituted olefins exhibited a lower reactivity and tri‐ and tetrasubstituted olefins did not react at all. A very high turnover number (TON) for the [Ru(TPP)CO] (TPP = tetraphenylporphyrin dianion) catalyzed amination of α‐methylstyrene by p‐nitrophenyl azide was obtained.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Red Pyrroloquinoline Alkaloids from the Mushroom Mycena haematopus
Authors: Peters Silke , Jaeger Robert J. R. , Spiteller Peter 
Published: October 2007

AbstractFour so far unknown red alkaloid pigments, haematopodin B (1) and the mycenarubins D (3), E (5) and F (6), were isolated from fruiting bodies of Mycena haematopus. The structures of these pyrroloquinoline alkaloids were established by 2D NMR spectroscopic and MS (ESI) methods. Their absolute configurations were determined by comparison of their CD spectra with that of haematopodin (2) or mycenarubin A (4). Metabolic profiling of the red pigments of intact and injured fruiting bodies revealed that the known degradation product haematopodin (2) originates from haematopodin B (1), which is the native main pigment of M. haematopus.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Rapid analysis of azo‐dyes in food by microchip electrophoresis with electrochemical detection
Authors: Dossi Nicolò , Piccin Evandro , Bontempelli Gino , Carrilho Emanuel , Wang Joseph 
Published: October 2007

AbstractA method based on microchip electrophoresis with electrochemical (EC) detection has been developed for the simultaneous determination of Yellow AB, Red 2G, Sunset Yellow, New Coccine, and Amaranth which are azo‐dyes frequently added to foodstuffs. Factors affecting both separation and detection processes were examined and optimized, with best performance achieved by using a 10 mM phosphate buffer (pH 11) as BGE solution and applying a voltage of 2500 V both in the separation and in the electrokinetic injection (duration 4 s). Under these optimal conditions, the target dye analytes could be separated and detected within 300 s by applying a detection potential of −1.0 V (vs. Ag/AgCl) to the glassy carbon (GC) working electrode. The recorded peaks were characterized by a good repeatability (RSD = 1.8–3.2%), high sensitivity, and a wide linear range. Detection limits of 3.8, 3.4, 3.6, 9.1, 15.1 μM were obtained for Yellow AB, Red 2G, Sunset Yellow, New Coccine, and Amaranth, respectively. Fast, sensitive, and selective response makes the new microchip protocol very attractive for the quantitative analysis of commercial soft drinks and candies.
Successful transverse patterning in amnesia using semantic knowledge
Authors: Moses Sandra N. , Ostreicher Melanie L. , Rosenbaum R. Shayna , Ryan Jennifer D. 
Published: October 2007

AbstractWe examined whether alternate systems compensate for deficient ones to process relations in amnesia. Transverse patterning (TP), a test of relating items to one another in memory, is reliably impaired in amnesia and has played a central role in testing hippocampal function. We facilitated successful TP in amnesia by providing familiar stimuli with semantically meaningful relationships. Tapping semantic knowledge allowed TP to be solved via extrahippocampal structures. Our work shows that by framing a situation as meaningful we can engage alternate neural systems to compensate for impairments. © 2007 Wiley‐Liss, Inc.