bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow cytometric measurement of calpain activity in living cells
Authors: Niapour Maryam , Berger Stuart 
Published: April 2007

AbstractBackground:Calpains are intracellular, calcium‐sensitive, neutral cysteine proteases that play crucial roles in many physiological and pathological processes. Calpain regulation is complex and activity is poorly correlated with calpain protein levels. Therefore a full understanding of calpain function requires robust methods for measuring activity.Methods:We describe and characterize a flow cytometric method for measuring calpain activity in live cells. This method uses the BOC‐LM‐CMAC reagent that readily diffuses into cells where it reacts with free thiols to enhance retention.Results:We show that the reagent is cleaved specifically by calpains and follows saturation kinetics. We use the assay to measure calpain activation following PDGF stimulation of rat fibroblasts. We also show that the calpain inhibitor PD150606 inhibits calpain with a Ki of 12.5 μM and show that Mek inhibitors PD89059 and U0126 also suppress calpain activity. We also show that the assay can measure calpain activity in subpopulations of cells present in unfractionated cord blood or in HL60 human myelomonocytic leukemia cells.Conclusion:Taken together, these experiments demonstrate that this assay is a reliable and useful method for measuring calpain activity in multiple cell types. © 2007 International Society for Analytical Cytology
Monocyte cholesterol homeostasis correlates with the presence of detergent resistant membrane microdomains
Authors: Wolf Zsuzsanna , Orsó Evelyn , Werner Tobias , Klünemann Hans. H. , Schmitz Gerd 
Published: April 2007

AbstractBackground:Lipid membrane microdomains are involved in the regulation of biological functions of monocyte membrane proteins. These microdomains show a relative resistance to non‐ionic detergents providing an easy analytical tool to study them.Methods:Here, we applied a rapid detergent‐based flow cytometric assay to investigate microdomain association of proteins on monocytes from whole blood samples. The association of known surface antigens with detergent resistant fraction of membranes (DRMs) was compared using monocytes from healthy blood donors, patients with genetic disorders affecting cellular cholesterol traffic and patients with systemic inflammatory response.Results:All investigated surface antigens of Niemann‐Pick type C (NPC)‐mutant monocytes with impaired cholesterol influx and defective late endosome cholesterol trafficking, presented a strongly increased DRM‐association. Though, membrane antigens of ATP binding cassette transporter A1 (ABCA1)‐mutant monocytes with impaired cholesterol efflux did not show alterations in DRM‐association. Differential CD14‐dependent receptor clustering within microdomains was also investigated in response to in vivo lipopolysaccharide (LPS) and/or atherogenic lipoprotein activation. Increased DRM‐association of the GPI‐anchored proteins CD14, CD55, the Fcγ receptor CD64, the scavenger receptors CD36, CD91 and CD163, the integrin CD11a, and complement receptor 3 complex CD11b/CD18 were observed from patients with systemic inflammatory response syndrome (SIRS)/sepsis or coronary artery disease (CAD)/myocardial infarction. Interestingly, the tetraspanin CD81 presented increased DRM‐association in SIRS/sepsis patients, but not in CAD patients. Moreover, the pentaspanin CD47 and the Fcγ RIII CD16 showed an increased DRM partition in CAD patients but disassembled from DRMs in SIRS/sepsis patients.Conclusions:Our results demonstrate that flow cytometric analysis of short time in situ detergent extraction provides a powerful tool for rapid screening of blood monocyte DRMs to preselect patients with potential raft/microdomain abnormalities for more detailed analysis. © 2007 International Society for Analytical Cytology
Monitoring dynamic protein expression in living E. coli. Bacterial cells by laser tweezers Raman spectroscopy
Authors: Chan James W. , Winhold Heiko , Corzett Michele H. , Ulloa Joshua M. , Cosman Monique , Balhorn Rod , Huser Thomas 
Published: April 2007

AbstractBackground:Laser tweezers Raman spectroscopy (LTRS) is a novel, nondestructive, and label‐free method that can be used to quantitatively measure changes in cellular activity in single living cells. Here, we demonstrate its use to monitor changes in a population of E. coli cells that occur during overexpression of a protein, the extracellular domain of myelin oligodendrocyte glycoprotein [MOG(1‐120)].Methods:Raman spectra were acquired from individual E. coli cells suspended in solution and trapped by a single tightly focused laser beam. Overexpression of MOG(1‐120) in transformed E. coli Rosetta‐Gami (DE3)pLysS cells was induced by addition of isopropyl thiogalactoside (IPTG). Changes in the peak intensities of the Raman spectra from a population of cells were monitored and analyzed over a total duration of 3 h. Data were also collected for concentrated purified MOG(1‐120) protein in solution, and the spectra compared with that obtained for the MOG(1‐120) expressing cells.Results:Raman spectra of individual, living E. coli cells exhibit signatures due to DNA and protein molecular vibrations. Characteristic Raman markers associated with protein vibrations, such as 1,257, 1,340, 1,453, and 1,660 cm−1, are shown to increase as a function of time following the addition of IPTG. Comparison of these spectra and the spectra of purified MOG protein indicates that the changes are predominantly due to the induction of MOG protein expression. Protein expression was found to occur mostly within the second hour, with a 470% increase relative to the protein expressed in the first hour. A 230% relative increase between the second and third hour indicates that protein expression begins to level off within the third hour.Conclusion:It is demonstrated that LTRS has sufficient sensitivity for real‐time, nondestructive, and quantitative monitoring of biological processes, such as protein expression, in single living cells. Such capabilities, which are not currently available in flow cytometry, open up new possibilities for analyzing cellular processes occurring in single microbial and eukaryotic cells. Published 2007 Wiley‐Liss, Inc.
Optimized amplification and fluorescent labeling of small cell samples for genomic array‐CGH
Authors: Knijnenburg Jeroen , van der Burg Marja , Tanke Hans J. , Szuhai Károly 
Published: April 2007

AbstractBackground:Whole genome amplification (WGA) is usually needed in the genetic analysis of samples containing a low number of cells. In genome‐wide analysis of DNA copy numbers by array comparative genomic hybridization (array‐CGH) it is very important that the genome is evenly represented throughout the amplified product. All currently available WGA techniques are generating some degree of bias.Methods:A way to compensate for this is using a reference sample which is similarly amplified, as the introduced amplification bias will be leveled out. Additionally, direct labeling of the amplified DNA is performed to bypass the currently widely applied random primed labeling, which involves an additional amplification of the product and is introducing extra bias.Results:In this article it is shown that equal processing of the test and reference sample is indeed crucial to generate an optimal array‐CGH profile of amplified DNA samples. Also presented here is that the labeling method may significantly effect the array‐CGH result, it is shown that with direct chemical labeling using platinum derivates (ULS labeling) optimal array‐CGH results are obtained.Conclusions:We show that an optimized WGA strategy for both test and reference sample in combination with direct chemical labeling results in a reliable array‐CGH profile of samples as low as a 30 cell equivalent. © 2007 International Society for Analytical Cytology
Developmental phenotypes and reduced Wnt signaling in mice deficient for pygopus 2
Authors: Li Boan , Rhéaume Catherine , Teng Andy , Bilanchone Virginia , Munguia Jesus E. , Hu Ming , Jessen Shannon , Piccolo Stefano , Waterman Marian L. , Dai Xing 
Published: April 2007

AbstractCanonical Wnt signaling involves complex intracellular events culminating in the stabilization of β‐catenin, which enters the nucleus and binds to LEF/TCF transcription factors to stimulate gene expression. Pygopus was identified as a genetic modifier of Wg (Wnt homolog) signaling in Drosophila, and encodes a PHD domain protein that associates with the β‐catenin/LEF/TCF complex. Two murine pygopus paralogs, mpygo1 and mpygo2, have been identified, but their roles in development and Wnt signaling remain elusive. In this study, we report that ablation of mpygo2 expression in mice causes defects in morphogenesis of both ectodermally and endodermally derived tissues, including brain, eyes, hair follicles, and lung. However, no gross abnormality was observed in embryonic intestine. Using a BAT‐gal reporter, we found Wnt signaling at most body sites to be reduced in the absence of mpygo2. Taken together, our studies show for the first time that mpygo2 deletion affects embryonic development of some but not all Wnt‐requiring tissues. genesis 45:318–325, 2007. © 2007 Wiley‐Liss, Inc.
Optimized interesterification of virgin olive oil with a fully hydrogenated fat in a batch reactor: Effect of mass transfer limitations
Authors: Criado Manuel , Hernández‐Martín Estela , Otero Cristina 
Published: April 2007

AbstractThe lipase‐catalyzed interesterification of virgin olive oil and fully hydrogenated palm oil (FHPO) was studied in a batch reactor operating at 75 °C. The reactions between olive oil {rich in OOO (32.36%), OPO (21.7%) and OLO (11.6%) [L = linoleic; O = oleic; P = palmitic acid]} and the fully hydrogenated fat {(36.5% PSP, 28.8% PPP, 23.2% SPS) [S = stearic acid]} produced semi‐solid fats. For an initial weight ratio of olive oil to FHPO of 60 : 40, the reaction product is a complex mixture of triacylglycerol (TAG) species. The TAG profile of the fat product is time dependent. Because of the high viscosity of the liquid reagent phase, it was important to determine if mass transfer effects were significant. Hence, the reaction was optimized with respect to the type and speed of agitation employed, temperature, use of solvent, and the type of biocatalyst. Three immobilized lipases [from Thermomyces lanuginosus (TL IM), Rhizomucor miehei (RM IM) and Candida antarctica B (Novozym 435)] were compared as catalysts for the interesterification reaction. Equilibrium is reached four times faster (in 1–4 h) with a magnetic stirrer to provide agitation than when agitation is not sufficient, i.e. when orbital agitation is employed. Equilibrium was reached faster with Lipozyme TL IM than with the other two lipases. The effects of all the factors investigated on the composition of the products have also been determined. Semi‐solid fats obtained with the non‐specific Novozym 435 contain levels of unsaturated fatty acid residues on sn‐2 sites that are similar to the products obtained with the 1(3)‐regiospecific enzymes Lipozyme TL IM and RM IM. The chemical properties of the product semi‐solid fat were characterized. The fat prepared using optimal reaction conditions contained 17.20% OPO, 13.61% OOO, 11.09% POP, and 10.35% OSP isomers as the primary products. The induction time obtained in the assay of the oxidative stability of the fat product was 21 h at 98 °C. The lipases Lipozyme TL IM and Novozym 435 were very stable with residual activities of 90 and 100%, respectively, after 15 batch reaction cycles.
Diastereoselective Cyclisation of N‐Alkenylideneamines into 3,4‐Dihydro‐2H‐pyrrol‐1‐ium Halides
Authors: Schley Daniela , Liebscher Jürgen 
Published: April 2007

AbstractA number of new chiral 2‐(α‐bromoalkyl)pyrrolinium salts and 2‐(α‐selenoalkyl)pyrrolidines were synthesized by the halocyclisation and selenocyclisation, respectively, of N‐(alkenylidene)alkylamines and subsequent reduction. These cyclisations were implemented in a diastereomeric fashion for the first time. Substrate control (starting imines possessing chirality in the N‐alkyl or the N‐alkenyl substituent) and reagent control (chiral organoselenenyl bromides) wereapplied. Asymmetric induction by stereocentres of the alkenylidene or double asymmetric induction by chiral selenenyl bromides on unsaturated imines with a chiral N‐alkyl group resulted in diatereoselectivities up to 84:16. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Organocatalytic Synthesis of Drugs and Bioactive Natural Products
Authors: Marcia de Figueiredo Renata , Christmann Mathias 
Published: April 2007

AbstractCatalytic reactions are a key element in the design of sustainable chemical processes. As witnessed in the field of transition metal‐catalysed processes, only those reactions that are reliable over a broad substrate range and tolerant toward a multitude of functional groups have found their way into the repertoire of preparative chemists. Natural product synthesis provides a good benchmark for the maturity of a new synthetic method and in this microreview we discuss the scope and limitations of organocatalytic reactions in the synthesis of biologically important molecules. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
IGF‐I plus E2 induces proliferation via activation of ROS‐dependent ERKs and JNKs in human breast carcinoma cells
Authors: Lin Cheng‐Wei , Yang Liang‐Yo , Shen Shing‐Chuan , Chen Yen‐Chou 
Published: April 2007

AbstractInduction of 17β‐estradiol (E2) and insulin‐like growth factor‐I (IGF‐I) has been detected in breast carcinoma, however the interaction between E2 and IGF‐I in the proliferation of breast carcinoma cells is still unclear. In the present study, we found that IGF‐I enhances the E2‐induced proliferation in MCF‐7 human breast carcinoma cells in accordance with stimulation of colony formation via a soft agar assay. Activation of insulin receptor substrate‐1 (IRS‐1) protein and extracellular signal‐related kinases (ERKs) and c‐Jun N‐terminal kinases (JNKs), but not p38 mitogen‐activated protein kinase (MAPK), via phosphorylation induction was detected in MCF‐7 cells treated with IGF‐I plus E2 (E2/IGF‐I). E2/IGF‐I‐induced proliferation was blocked by chemical inhibitors of ERKs (PD98059) and JNKs (SP600125). An increase in the expression of c‐Jun protein was detected in E2/IGF‐I‐treated MCF‐7 cells, and this was inhibited by PD98059 and SP600125. Transfection of the dominant negative MEKK and JNK plasmids significantly reduced E2/IGF‐I‐induced proliferation with suppression of c‐Jun protein expression. An increase in peroxide production was detected in E2/IGF‐I‐treated cells, and N‐acetyl‐L‐cysteine (NAC) and Tiron (TIR) addition significantly inhibited E2/IGF‐I‐induced cell proliferation with blocking of the phosphorylation of ERKs and JNKs, and the expression of c‐Jun protein. Additionally, 3‐OH flavone, baicalein, and quercetin showed effective inhibitory activities against E2/IGF‐I‐induced proliferation through suppressing proliferative events such as phosphorylation of IRS‐1, ERKs, and JNKs proteins, and induction of c‐Jun protein and colony formation. These results indicate that IGF‐I interacts with E2 to promote the proliferation of breast carcinoma cells via ROS‐dependent MAPK activation and c‐Jun protein expression. The structure‐related inhibition of E2/IGF‐I‐induced proliferative events by flavonoids is elucidated. J. Cell. Physiol. 212:666–674, 2007. © 2007 Wiley‐Liss, Inc.
Intercomparison of global cloud cover fields over oceans from the VOS observations and NCEP/NCAR reanalysis
Authors: Bedacht Ernst , Gulev Sergey K. , Macke Andreas 
Published: April 2007

AbstractThe paper inter‐compares the total cloud cover over the World Ocean from marine visual observations assimilated in the International Comprehensive Ocean‐Atmosphere Data Set (ICOADS) and National Centers of Environmental Prediction/National Center of Atmospheric Research (NCEP‐NCAR) reanalysis. The Intercomparison covers the period from 1948 to 2002. NCEP‐NCAR reanalysis shows about 10% of fractional cloud cover smaller than the visual observations do. The largest differences are observed in the mid and sub‐polar latitudes. In the tropics, NCEP‐NCAR data show slightly higher cloud cover then ICOADS. These systematic differences are quite persistent through the year with somewhat stronger differences in summer. Comparison of the characteristics of inter‐annual variability shows little consistency between visually observed total cloud cover and total cloudiness diagnosed by the reanalysis. Linear trends are primarily positive in the ICOADS cloud data, while in the NCEP‐NCAR reanalysis they show downward trends in the tropics and upward tendencies in the mid and high latitudes. Analysis of the effect of sampling in ICOADS shows that sampling inhomogeneity cannot fully explain the disagreements observed. At the same time, the major climate variability patterns such as North Atlantic Oscillation (NAO) and El‐Nino—Southern Oscillation (ENSO) are well captured in both ICOADS and NCEP‐NCAR cloud cover data sets. Copyright © 2007 Royal Meteorological Society
Revascularization after segmental resection of lower extremity soft tissue sarcomas
Authors: Adelani Muyibat A. , Holt Ginger E. , Dittus Robert S. , Passman Marc A. , Schwartz Herbert S. 
Published: April 2007

AbstractBackground and ObjectivesLimb salvage surgery combined with vascular reconstruction has replaced amputation as the preferred treatment of soft tissue sarcomas involving major vascular structures of the extremities. We describe our experience with soft tissue sarcomas involving major vascular structures and examine outcomes according to the type of graft selected for arterial reconstruction. We also examine the effect of venous reconstruction on post‐operative edema.MethodsThis retrospective review includes 14 patients with lower extremity soft‐tissue sarcomas that encased major vessels, requiring combined limb‐preserving tumor resection and revascularization with a synthetic or autogenous saphenous vein graft. Edema in patients with and without venous reconstruction was compared. The incidence of infection, wound dehiscence, and graft thrombosis were compared according to arterial graft type.ResultsThere was no significant difference in edema in patients with venous reconstruction and those without. There was also no significant difference in infection and graft thrombosis in patients with synthetic grafts and those with autogenous saphenous vein grafts. Wound dehiscence occurred more often in patients with synthetic grafts (P = 0.029).ConclusionsAlthough this study was small, these results suggest that further studies are needed to determine the roles that vascular graft selection and venous reconstruction play in clinical outcome. J. Surg. Oncol. 2007; 95: 455–460. © 2007 Wiley‐Liss, Inc.
A Characterization of a Certain Class of Compact Metric Spaces
Authors: Feiste U. 
Published: April 2007

AbstractCompact metric spaces χ of such a kind, that 𝔹f =𝔹(X), are characterized, 𝔹(X) is the σ‐field of BOREL sets and 𝔹f(X) is the field generated by all open subset of X. Our main result is Theorem 5: If χ is a compact metric space, then the following conditions are equivalent:

𝔹f(X) =𝔹(X).
card (X) ≦x0 and there are k, mϵN such that card (X(k)) = m.
There are k, mϵN such that χ is homeomorphic to ωk · m + 1.
Über eine Transformationseigenschaft der Nonionen
Authors: Hoehnke Hans‐Jürgen 
Published: April 2007

AbstractDie BRANDTsche Vermutung über den Zusammenhang zwischen den Multiplikationszahlen (auch Produkt‐ oder Strukturkonstanten genannt) einer assoziativen Algebra 𝔑 von endlichem Grad n über einem kommutativen Körper 𝔎 und den Koeffizienten der Normenform N (ξ) eines allgemeinen Elementes ξϵ𝔑, von ihm selbst für n = 2 (d. h. im Fall einer verallgemeinerten Quaternionenalgebra) verifiziert, wurde im Fall n = 3 in der Diss. des Verfassers [6] und dann allgemein in [7], [9] und davon unabhängig, doch mit der Einschränkung einer Charakteristik char 𝔎 ≠ 2, 𝔎 ≠ 3, von N. JACOBSON [11] bewiesen.Während der allemeine Beweis nicht zu Formeln führt, die diesen Zusammenhang explizite ausdrücken, wurde in [6] im Fall n = 3 dafür ein lineares Gleichungssystem gefunden. Da dieses Ergebnis im Hinblick auf vertiefte Strukturuntersuchungen assoziativer Algebren von allgemeinerem Interesse zu sein scheint, wird es nachstehend (in seiner ursprünglichen Fassung) vorgelegt.
1.6 W K‐band MMIC power amplifier developed using low loss matching technique for point‐to‐point radio applications
Authors: Bahl Inder J. 
Published: April 2007

AbstractThis paper presents the design approach and test results of a four‐stage 1.6‐W K‐band MMIC power amplifier developed for point‐to‐point radio applications. The design of the power amplifier was based on a small signal low loss matching technique. The MMIC was fabricated employing GaAs based high‐performance 0.4 μm multifunction self‐aligned gate MESFET technology. We achieved a minimum PAE of 22%, output power of 1.6 W (0.53 W/mm power density) and associate gain of 18 dB over the 17.5–20 GHz frequency range. Thus, we successfully applied a small signal technique in a four‐stage K‐band MMIC power amplifier to achieve bandwidth, power output and PAE performance objectives. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1521–1525, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22486
Novel dual‐mode DC‐block triangular‐patch bandpass filter
Authors: Li Ming , Yun Xiaohua , Liu Hai‐wen 
Published: April 2007

AbstractA novel dual‐mode DC‐block bandpass filter (BPF) using a pair of V‐shape slots on triangular‐patch resonators is developed in this letter. The V‐shape slots perturb the field distributions of triangular‐patch resonators and excite degenerate modes. Compared to our previous research, the length of input/output (I/O) lines of the proposed filter is reduced so that the circuit becomes compact. Finally, the good agreement between the simulated and measured results of the proposed BPF is presented. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1648–1649, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22520
Analysis of patch antennas on a multilayer substrate with a embedded periodic structure
Authors: Rajo‐Iglesias Eva , Inclán‐Sánchez Luis , García‐Muñoz Luis‐Enrique 
Published: April 2007

AbstractThe goal of this work is to further investigate on the use of a truncated planar metallic periodic structure (grounded FSS‐based) to create new resonance frequencies in a patch antenna. The periodic structure is placed inside the microstrip patch antenna (between the metallic ground plane and the patch) in the middle of a multilayer dielectric. The frequency behavior of the antenna as a function of the parameters of this periodic structure has been studied. Also the extension to a stacked patches configuration, which provides another resonance frequency, has been validated. Final antenna design presents flexible multiband operation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1717–1722, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22527