bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling the tensile behavior of fiber bundles with irregular constituent fibers
Authors: He Wendy W. , Wang Xungai 
Published: July 2004

AbstractIn this article, the effect of fiber dimensional irregularities on the tensile behavior of fiber bundles is modeled with the finite element method. The fiber dimensional irregularities are simulated with sine waves of different magnitudes. The specific‐stress/strain curves of fiber bundles and their constituent single fibers are obtained and compared. The results indicate that fiber diameter irregularity along the fiber length has a significant effect on the tensile behavior of fiber bundles. For a bundle of uniform fibers of different diameters, all the constituent fibers will break simultaneously, regardless of the fiber diameter. Similarly, if fibers within a bundle have the same pattern and level of diameter irregularity along the fiber length, the fibers will break at the same time, also regardless of the difference in the average diameter of each fiber. In these cases, the specific‐stress/strain curve for the bundle overlaps with that of the constituent fibers. When a fiber bundle consists of single fibers with different levels of diameter irregularities, the specific‐stress/strain and load–elongation curves of the fiber bundle have a stepped or ladder shape. The fiber with the highest irregularity breaks first, even when the thinnest section of the fiber is still coarser than the diameter of a very thin but uniform fiber in the bundle. This study suggests that fiber diameter irregularity along the fiber length is a more important factor than the fiber diameter itself in determining the tensile behavior of a fiber bundle consisting of irregular fibers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2664–2668, 2004
New insights into the development of popliteal cysts
Authors: Labropoulos N , Shifrin D A , Paxinos O 
Published: July 2004

Abstract

Background
This prospective study was designed to investigate the aetiology of popliteal (Baker's) cysts.

Methods
Some 426 legs in 312 individuals were investigated with ultrasonography for the presence of a popliteal cyst. Participants included healthy volunteers, patients with a painful knee, and a group of patients with signs and symptoms of deep vein thrombosis (DVT). The location, thickness and content of all cysts were recorded. In addition, the popliteal fossa was dissected in four cadaver knees.

Results
The prevalence of popliteal cyst increased with age and was significantly higher in those aged over 50 years (P &lt; 0·001). Compared with controls (incidence 3·0 per cent), cysts were more common in patients with DVT symptoms (9·5 per cent; P = 0·141) and those with painful knees (19·8 per cent; P &lt; 0·001). All cysts were located in the posteromedial aspect of the popliteal fossa; the majority extended between the deep fascia and the medial head of the gastrocnemius muscle. At this level an area without external support of the posterior capsule was identified between the two expansions of the semimembranosus muscle from the medial side (the oblique popliteal ligament and the expansion over the popliteus muscle) and the posterior cruciate ligament from the lateral side. This area was also located in the knee dissections. No association was found between popliteal cyst and acute DVT.

Conclusion
Popliteal cysts are relatively common in patients over 50 years old with a painful knee or with signs and symptoms of DVT. They form in the posteromedial popliteal fossa because the synovial capsule does not provide anatomical support in this region.
Quantitation of the large polypeptide glucagon by protein precipitation and LC/MS
Authors: Delinsky David C. , Hill Kim T. , White Catherine A. , Bartlett Michael G. 
Published: July 2004

AbstractWe present a method for the quantitation of glucagon from rat plasma by protein precipitation and LC/MS. No internal standard was used, as a labeled standard was not available and similar peptides did not show comparable extraction characteristics to glucagon. The LC system included a Keystone C18, 300 Å pore size column; a linear gradient was used with a mobile phase consisting of water and acetonitrile, each with 0.2% acetic acid and 0.02% trifluoroacetic acid. Glucagon was detected with the mass spectrometer in positive ion mode monitoring the 4+ charge state at m/z 871.7. The method had an approximated limit of detection of 1 ng/mL. The lower limit of quantitation (LLOQ) was 25 ng/mL (7.2 fmol/mL), which could be reduced with an appropriate internal standard. External calibration was used and calibration curves were found to be linear over the range from 25 to 1000 ng/mL (7.2 to 290 fmol/mL). The method showed a high degree of precision and accuracy both within and between runs at four validation points, including the LLOQ. Copyright © 2004 John Wiley & Sons, Ltd.
A validated HPLC assay to monitor riluzole plasma or serum concentrations in patients with amyotrophic lateral sclerosis
Authors: van Kan H. J. M. , Spieksma M. , Groeneveld G. J. , Toraño J. Sastre , van den Berg L. H. , Guchelaar H. J. 
Published: July 2004

AbstractA specific, accurate and precise high‐performance liquid chromatographic assay was developed for the determination of riluzole, a drug used to treat patients with amyotrophic lateral sclerosis. Samples were treated by extraction with dichloromethane followed by reversed‐phase chromatography with ultraviolet detection at 260 nm. Preset validation criteria were met from 20 to 2000 ng/mL with a linear response curve. Extraction recovery of riluzole was 65–76%. The accuracy of the method was 102–103%. Intra‐ and inter‐day coefficients of variation were in the ranges 2.8–4.9% and 1.8–9.7%. A detection limit of 5 ng/mL was found. Determination of concentrations in serum and plasma resulted in similar results below 500 ng/mL. At higher values a matrix effect cannot be excluded. This presented method can be used to monitor plasma or serum levels in ALS patients treated with riluzole. Copyright © 2004 John Wiley & Sons, Ltd.
Photolysis of NSAIDs. IV. Photoproducts of zomepirac determined by LC‐ESI‐MS
Authors: Wang Ching‐Chiung , Chen Fu‐An , Chen Chih‐Jui , Chao Su‐Hui , Wu An‐Bang 
Published: July 2004

AbstractA sample of 10 mm zomepirac in methanol was photo‐irradiated with a Hanovia 200 W high‐pressure quartz Hg lamp for 14 days. In total, four photoproducts were observed from the HPLC chromatogram. The preparative HPLC included an YMC‐Pack Pro C18 column (250 × 20 mm i.d.), a mobile phase of CH3CN–CH3OH–1%HOAc (10:60:30, v/v/v), and UV detection at 254 nm. The most probable structures of the four photoproducts were determined by LC‐MS. Two major photoproducts were separated, and their structures were further conﬁrmed by the spectroscopic methods. A reaction scheme of zomepirac was proposed that the photochemical reaction routes occur mainly via bond ﬁssion between carbonyl–pyrrolyl groups (α‐cleavage of a ketone), and decarboxylation followed by oxidation with singlet oxygen to produce an aldehyde. Copyright © 2004 John Wiley & Sons, Ltd.
An optimized protocol for nano‐LC‐MALDI‐TOF‐MS coupling for the analysis of proteolytic digests of glycoproteins
Authors: Lochnit Günter , Geyer Rudolf 
Published: July 2004

AbstractMatrix‐assissted laser desorption ionization time‐of‐ﬂight mass spectrometry (MALDI‐TOF‐MS) analyses of complete proteolytic digests are often hampered by contaminations and the complexity of the sample. This results in suppression effects and the formation of adducts which are difﬁcult to assign, thus leading to low scores in database searches. In particular, signals of post‐translationally modiﬁed peptides such as glycopeptides are often of low intensity or completely suppressed. Online liquid chromatography electrospray ionization mass spectrometry (ESI‐MS) can, in part, overcome this problem, but the analytes are completely consumed during the run. Coupling of nano‐ﬂow HPLC (nano‐LC), microfractionation and MALDI‐TOF‐MS combines separation and high‐sensitivity UV detection with the possibility of collecting fractionated peptides and preserving the sample for detailed mass spectrometric analyses. Here we report on an optimized protocol for nano‐LC‐MALDI‐TOF‐MS analyses of glycoproteins. This protocol improves spectral quality, resulting in better protein identiﬁcation scores in database searches. Furthermore, post‐translationally modiﬁed peptides could be detected with higher sensitivity by changing the experimental conditions, allowing assignment, localization and characterization of the respective carbohydrate substituents. Copyright © 2004 John Wiley & Sons, Ltd.
Identiﬁcation and determination of effective components in Euphrasia regelii by capillary zone electrophoresis
Authors: Shuya Cui , Shengda Qi , Xingguo Chen , Zhide Hu 
Published: July 2004

AbstractA capillary zone electrophoresis (CZE) method has been developed for simultaneous determination of eukovoside, cinnamic acid and ferulic acid in Euphrasia regelii for the ﬁrst time. The electrophoresis buffer was 20 mmol/L sodium borate containing 10% (v/v) methanol (pH 8.50). The effects of concentration of borate and electrolyte pH on electrophoretic behavior and separation were studied. Regression equations revealed linear relationships (correlation coefﬁcients 0.9995–0.9998) between the peak area of each analyte and the concentration. The levels of analytes in the different parts of Euphrasia regelii were easily determined with recoveries ranging from 95.5 to 104.2%. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of ropivacaine and antipyrine by high performance liquid chromatography and its application to the in vitro transplacental study
Authors: Zuo Ming , Duan Geng‐Li , Ge Zhen‐Gong 
Published: July 2004

AbstractA simple and reliable RP‐HPLC method has been developed for the simultaneous determination of ropivacaine and antipyrine in perfusate samples. Samples were analyzed on an ODS column with UV detection at 210 nm after liquid–liquid extraction. The mobile phase consisted of potassium dihydrogenphosphate (25 mm, adjusted to pH 5.0 with phosphoric acid)–acetonitrile (79:21, v/v). The method has been validated to be precise, accurate and linear. It has been applied to the investigation of placental transfer of ropivacaine via a dually perfused cotyledon model of human placenta in vitro. Copyright © 2004 John Wiley & Sons, Ltd.
Chiral Recognition by Resorcin[4]arene Receptors: Intrinsic Kinetics and Dynamics
Authors: Tafi Andrea , Botta Bruno , Botta Maurizio , Delle Monache Giuliano , Filippi Antonello , Speranza Maurizio 
Published: July 2004

AbstractMolecular recognition of representative amino acids (A) by a chiral amido[4]resorcinarene receptor (1L) was investigated in the gas phase by ESI‐FT‐ICR mass spectrometry. The ligand displacement reaction between noncovalent diastereomeric [1L⋅H⋅A]+complexes and the 2‐aminobutane enantiomers (B) exhibits a distinct enantioselectivity with regard to both the leaving amino acid A and the amine reactant B. The emerging selectivity picture, discussed in the light of molecular mechanics and molecular dynamics calculations, points to chiral recognition by1L, as determined by the effects of the host asymmetric frame on the structure, stability, and rearrangement dynamics of the diastereomeric [1L⋅H⋅A]+complexes and the orientation of the amine reactant B in encounters with [1L⋅H⋅A]+. The results contribute to the development of a dynamic model of chiral recognition of biomolecules by enzyme mimics in the unsolvated state.
The kallikrein‐kinin system, angiotensin converting enzyme inhibitors and insulin sensitivity
Authors: Damas J. , Garbacki N. , Lefèbvre P. J. 
Published: July 2004

AbstractThe therapeutic use of angiotensin converting enzyme (ACE) inhibitors, at a large scale, in arterial hypertension has showed that these molecules can exert beneficial effects on insulin sensitivity and may reduce the occurrence of type 2 diabetes mellitus. One hypothesis explaining these effects of ACE inhibitors may relate to their capacity to interfere with bradykinin (BK) metabolism and action. BK may participate in the regulation of substrate utilization by several tissues by improving blood flow and substrate delivery to the tissues and also by promoting translocation of glucose transporters. Moreover, BK has been shown to increase phosphorylation of insulin receptor and its cell substrates. BK also appears to improve the release of insulin. Furthermore, insulin may activate the kallikrein‐kinin system, which consequently may increase its metabolic effects. However, in experimental diabetes mellitus, BK can participate to the inflammatory reaction leading to Langerhans islets destruction. In diabetes, whereas tissue kallikrein mRNA levels were reduced in several organs, an overexpression of kinin receptors, an increase in plasma levels of kininogens and kallikrein and an activation of the kinin system have all been reported. Lastly, kinins may be involved in the development of diabetic nephropathy. Reduction of kinin metabolism by ACE inhibitors might be involved in the beneficial effects exerted by these compounds in diabetic kidney functions. Copyright © 2004 John Wiley & Sons, Ltd.
Diabetes mellitus and alcohol
Authors: van de Wiel Albert 
Published: July 2004

AbstractAlcohol influences glucose metabolism in several ways in diabetic patients as well as in non‐diabetic patients. Since alcohol inhibits both gluconeogenesis and glycogenolysis, its acute intake without food may provoke hypoglycaemia, especially in cases of depleted glycogen stores and in combination with sulphonylurea. Consumed with a meal including carbohydrates, it is the preferred fuel, which may initially lead to somewhat higher blood glucose levels and hence an insulin response in type 2 diabetic patients. Depending on the nature of the carbohydrates in the meal, this may be followed by reactive hypoglycaemia.Moderate consumption of alcohol is associated with a reduced risk of atherosclerotic disorders. Diabetic patients benefit from this favourable effect as much as non‐diabetic patients. Apart from effects on lipid metabolism, haemostatic balance and blood pressure, alcohol improves insulin sensitivity. This improvement of insulin sensitivity may also be responsible for the lower incidence of type 2 diabetes mellitus reported to be associated with light‐to‐moderate drinking. In case of moderate and sensible use, risks of disturbances in glycaemic control, weight and blood pressure are limited.Excessive intake of alcohol, however, may not only cause loss of metabolic control, but also annihilate the favourable effects on the cardiovascular system. Copyright © 2004 John Wiley & Sons, Ltd.
PLCγ2 regulates Bcl‐2 levels and is required for survival rather than differentiation of marginal zone and follicular B cells
Authors: Bell Sarah E. , Vigorito Elena , McAdam Simon , Reynolds Helen M. , Caraux Anouk , Colucci Francesco , Turner Martin 
Published: July 2004

AbstractB cells from phospholipase C (PLC)γ2‐deficient mice express reduced levels of the pro‐survival protein Bcl‐2 and show a defect in the development of transitional T3 and marginal zone (MZ) B cells that reflects reduced B cell survival. Introduction of a bcl‐2 transgene restored the numbers of MZ, T3 and follicular B cells in PLCγ2–/– mice. Restricting the B cell repertoire in PLCγ2‐deficient mice by the introduction of a BCR transgene resulted in a striking reduction in the number of IgM‐positive B cells and a paucity of IgD‐expressing cells in the spleen which was also rescued by the bcl‐2 transgene. BCR‐stimulated ERK and IκBα phosphorylation were PLCγ2 dependent, while calcium flux was reduced, but not abrogated, in the absence of PLCγ2, suggesting an ancillary role for PLCγ1. The bcl‐2 transgene rescued development of PLCγ2–/– B cells and serum IgM levels but did not restore BCR‐mediated signaling, proliferation or serum IgG3 levels. These data suggest that PLCγ2 performs a critical role in B cell development through regulation of survival rather than differentiation.
CD4‐induced down‐regulation of T cell adhesion to B cells is associated with localization of phosphatidyl inositol 3‐kinase and LFA‐1 in distinct membrane domains
Authors: Trucy Maÿlis , Barbat Christiane , Sorice Maurizio , Fischer Alain , Mazerolles Fabienne 
Published: July 2004

AbstractWe have previously shown that binding of anti‐CD4 antibody inhibit LFA‐1‐dependent adhesion between CD4+ T cells and B cells in a p56lck and a PI3‐kinase‐dependent manner. In this work, we investigated with two different T cell lines (Jurkat and A201) whether CD4 binding could alter interactions of the proteins putatively involved in this adhesion regulatory pathway. Anti‐CD4 binding was shown to induce a transient association between PI3‐kinase and LFA‐1, which took place in different regions of the plasma membrane. It was detected in detergent soluble membrane but also in detergent insoluble membrane consisting in raft microdomains, composed of GM1 and/or GM3 gangliosides. These results show that anti‐CD4 Ab could modify the interaction between LFA‐1 and signaling molecules, such as PI3‐kinase and induce, in part, their recruitment in raft domains. By using specific inhibitors, raft integrity and CD4 association with GM3 were found necessary for observing the CD4‐dependent inhibition of LFA‐1‐mediated adhesion. These results strongly suggest that these molecular rearrangements in the membrane are necessary to induce down‐regulation of LFA‐1‐mediated adhesion.
Antigenicity and immunogenicity of peptide analogues of a low affinity peptide of the human telomerase reverse transcriptase tumor antigen
Authors: Hernández Javier , Schoeder Kim , Blondelle Sylvie E. , Pons Fancisco Garcia , Lone Yu Chun , Simora April , Langlade‐Demoyen Pierre , Wilson Darcy B. , Zanetti Maurizio 
Published: July 2004

AbstractHuman telomerase reverse transcriptase (hTRT) is a potential target for therapeutic vaccination against cancer. Therefore, it is critically important to identify T cell epitopes useful to induce cytotoxic T cell responses. Here we used a positional scanning combinatorial peptide library to identify peptide analogues for a previously characterized low affinity hTRT peptide (p572). From an initial library containing over 300 billion different peptides and through successive rounds of selection, we retained 72 candidate peptide analogues for further assessment of antigenicity and in vivo immunogenicity in HLA A2.1‐transgenic mice. While antigenically cross‐reactive with p572, only a fraction of these peptides was immunogenic in mice. Immunogenicity appeared to correlate with the stability of binding to the MHC molecule and the presence of HLA A2.1 anchor residues in position 2 and 9. Two peptides differing by five residues from the reference p572 (p49 and p50) were more effective than p572 in inducing CTL cross‐reacting with p572 in HLA A2.1‐transgenic mice. Both peptides also expanded specific CTL in peripheral blood lymphocytes of normal human volunteers ex vivo. The present study shows that positional scanning combinatorial peptide libraries can be used to identify hTRT peptide analogues for inclusion in a cancer vaccine.
Frontline: Characterization of BT3 molecules belonging to the B7 family expressed on immune cells
Authors: Compte Elsa , Pontarotti Pierre , Collette Yves , Lopez Marc , Olive Daniel 
Published: July 2004

AbstractNew members of the B7 family have been recently described as regulators of T cell activation and function. Butyrophilin (BT) has also been related to the B7 family by sequence similarity analyses. We present a new subfamily called BT3, which belongs to the B7/BT family. The BT3 subfamily comprises three members (BT3.1, .2 and .3) that exhibit 95% identity and form a monophylogenetic group along with the BT‐related members. High expression levels of BT3 transcripts were detected in lymphoid tissues (mainly spleen, lymph node and PBL). Using anti‐BT3 mAb we could demonstrate BT3 expression on immune cells including T, B and NK cells, monocytes and dendritic cells as well as hematopoietic precursors and some tumor cell lines. As described earlier for PDL‐1 and ICOS‐L, BT3 molecules are expressed on endothelial cells and up‐regulated upon activation by IFN‐γ or TNF‐α. The BT3.1 counter‐receptor (BT3.1‐R) was analyzed by means of binding experiments using BT3.1‐Ig soluble protein. The BT3.1‐R is not CD28, CTLA‐4, ICOS, PD‐1 or BTLA and seems restricted to some T cell and hematopoietic cell lines. Altogether, these data describe new members of the B7/BT family that may play a role in regulation of the immune response.See accompanying commentary http://dx.doi.org/10.1002/eji.200425388
Commentary: Regulated equilibrium between opposite signals: a general paradigm for T cell function?
Authors: Moretta Alessandro , Bottino Cristina 
Published: July 2004

AbstractThe co‐signaling receptors specific for the different members of the B7 molecular family are cell surface glycoproteins that are essential to modulate and tune the TCR‐mediated activation of T lymphocytes. The common characteristic is that their function appears to be dependent on the engagement of TCR by antigenic peptides presented in the MHC context by antigen‐presenting cells. Interestingly, co‐signaling molecules can be distinguished into costimulators and co‐inhibitors, the prototype being represented by CD28 and CTLA‐4, respectively. In the case of costimulators, the co‐signals integrate the signal originated from the TCR resulting in optimal T cell activation (two‐signal model). In the case of co‐inhibitors, the co‐signals would moderate and/or switch off the Ag‐dependent T cell activation, thus acting as negative regulators of immune responses. The growing number of novel co‐signaling molecules has recently highlighted the need to integrate the two‐signal model with the emerging data on the different co‐inhibitory interactions. Thus, a model has been proposed based on the idea that the TCR signal alone cannot take a full decision on the nature of the functional outcome following an antigen‐specific stimulation and that this final event is governed by the co‐signaling molecules.See accompanying accompanying article http://dx.doi.org/10.1002/eji.200425227
The variation of antioxidant activities and chemical composition of essential oils of Teucrium orientale L. var. orientale during harvesting stages
Authors: Yildirim Ali , Cakir Ahmet , Mavi Ahmet , Yalcin Mehmet , Fauler Gunter , Taskesenligil Yavuz 
Published: July 2004

AbstractThe aerial parts of Teucrium orientale L. var. orientale were collected at the budding, ﬂowering and vegetative stages. In the each stage, essential oils were obtained by hydrodistillation and steam distillation. The chemical compositions of the essential oils were analysed by GC and GC–MS; 43 different compounds were determined in total, and more than 96% of the essential oils were identiﬁed by GC and GC–MS. They contain mainly linalool, β‐caryophyllene, 3‐octanol, phytol, β‐bourbonene and germacrene D. Among the steam distillation oils, the highest 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity was found at the budding stage and the lowest at the vegetative stage. At all stages, the DPPH radical scavenging activities of hydrodistillation oils were markedly lower than those of steam distillation oils. Steam distillation oils of the budding and ﬂowering stages showed the highest antioxidant activities. However, steam distillation oils of the vegetative stage in two doses (200 and 400 µg) did not show antioxidant activities (p > 0.05, between these and control). None of the hydrodistillation oils showed detectable antioxidant activity. In contrast, in the presence of 400 µg hydrodistillation oils of ﬂowering stage, prooxidant activity was found in the linoleic acid emulsion. Copyright © 2004 John Wiley & Sons, Ltd.