bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypoelasticity‐based analytical stress solutions in the simple shearing process
Authors: Lin R. 
Published: March 2003

AbstractIn the present work a set of hypoelasticity‐based analytical stress solutions of simple shearing is formulated. The rate constitutive equations based on the Jaumann, Green‐Naghdi, Oldroyd, Truesdell, Cotter‐Rivlin, logarithmic and OE‐ and OL‐based stress rates are exploited. From a representation principle of the material spins, a concise formula of the spin tensors for simple shearing is derived. Based on the derived spin equation a novel analytical stress solution related to the OL‐based stress rates is formulated. For completeness the issued stress solutions in conjunction with the other stress rates are also reformulated. All analytical stress solutions are illustrated and compared.
Effects of viscosity on linear gravity waves due to surface disturbances in water of finite depth
Authors: Bandyopadhyay A. 
Published: March 2003

AbstractThe three‐dimensional problem of waves due to an arbitrary initial time‐dependent surface pressure together with an elevation of the surface in a viscous fluid of constant finite depth h is examined. It is shown that the multiple‐integral expression for the surface displacement ζ is reducible to one which is correct to terms of order O(ν'), ν' = ν/(4gh3)1/2, for small coefficient of viscosity ν, under certain conditions. When the Laplace inversion is completed in ζ we arrive at new results which differ significantly from those obtained in an earlier analysis of the problem by Nikitin and Potetyunko [1].
Response of a diffusion‐wave system subjected to deterministic and stochastic fields
Authors: Agrawal O.P. 
Published: March 2003

AbstractThis paper presents a general analytical technique for a Fractional Diffusion‐Wave (FDW) system subjected to a non‐homogeneous field, which can be deterministic or stochastic. In this formulation, the response of the system is written as a linear combination of the eigenfunctions which are identified using the method of separation of variables. The properties of the eigenfunctions are used to reduce the FDW equation defined in space‐time domain into a set of infinite Fractional Differential Equations (FDEs) defined in the time domain only. A Laplace transform technique is used to obtain the fractional Green's function and a Duhamel integral type expression for the system's response. For a stochastic analysis, the input field is treated as a random process with specified mean and correlation functions. An expectation operator is applied on a set of expressions to obtain the stochastic characteristics of the system. Several special cases are discussed and numerical results are presented to show the deterministic and stochastic response of FDW systems. When the order of the fractional derivative of the equation is <1, 1, >1, and 2 the equation represents a model of a sub‐diffusion, a diffusion, a diffusion‐wave propagation, and a wave propagation system, respectively. Thus the formulation provides a unified approach for stochastic analysis of all these systems. The approach can be equally applied to all those systems for which the existence of eigenmodes is guaranteed.
Detection of Intestinal Ischemia Using a Microdialysis Technique in an Animal Model
Authors: Sommer Thorbjorn , Larsen Jens Fromholt 
Published: March 2003

AbstractThe purpose of this study was to use a microdialysis technique to demonstrate the metabolic changes that occur in the intestinal wall during ischemia in vivo. Continuous monitoring of glucose, lactate, and glycerol using a microdialysis technique was performed in the jejunal wall of 10 pigs during steady‐state and occlusive ischemia. The microdialysis catheters were introduced 50, 80, and 110 cm from the ligament of Treitz. Occlusive ischemia was established to two segments after steady state was reached. Microdialysate samples were collected from ischemic/nonischemic intestinal segments simultaneously every 20 minutes. For comparison with the microdialysis measurements, systemic blood samples were drawn from the cannulated femoral artery and analyzed consecutively. A significant increase of microdialysate lactate and a significant decrease of microdialysate glucose were found during occlusive ischemia as compared to the preischemic samples and samples from the nonischemic control catheters. The microdialysate glycerol increased during ischemia, but later than the lactate. No changes were observed in systemic serum lactate, serum glucose, pH, pco2, and po2, but serum potassium increased by 1.1 mmole (median) during ischemia. Microdialysis measured in the intestinal wall identifies local ischemia and may be a new method for the monitoring of intestinal perfusion.
Reconstruction after Distal Gastrectomy by Interposition of a Double‐jejunal Pouch Using a Triangulating Stapling Technique
Authors: Ikeda Masami , Ueda Tetsuro , Yamagata Kuniyoshi , Takatsuka Jun , Yamaguchi Muneyuki , Shiba Tadaaki 
Published: March 2003

AbstractSustaining good nutrition and preventing postgastrectomy syndrome are important for increasing the quality of life after distal gastrectomy. Many surgeons have proposed surgical methods designed to enhance long‐term patient quality of life. An immediate, safe method based on current physiologic reconstructive principles shown to reduce postoperative patient complaints is presented. A reconstructive method using a modified interpositioned double‐jejunal pouch after distal gastrectomy in 18 cancer patients was reviewed. This method uses a triangulating stapling technique with wide end‐to‐side anastomosis between the residual stomach and the pouch. In all patients, the anastomosis site was without leakage or stenosis, and there were no episodes of severe reflux esophagitis, residual gastritis, or dumping syndrome. The mean pooling rate was 44.2%, and emptying half‐time was 73.0 minutes. After 2 years the body weight was 91.3% of the preoperative weight, the food volume was 89.2% of normal intake, and meal frequency was 3.0 per day. This method of reconstruction is useful for immediate and safe creation of a wide anastomosis between the residual stomach and the double‐jejunal pouch after distal gastrectomy and in the prevention of esophagitis and residual gastritis.
An externally fixed femoral fracture model for mice
Authors: Cheung Kenneth M. C. , Kaluarachi Kumara , Andrew Glynne , Lu William , Chan Danny , Cheah Kathryn S. E. 
Published: March 2003

AbstractTransgenic and knockout mouse models can be used to help understand the molecular mechanisms of fracture repair. This study examines the feasibility of applying an external fixator to the mouse femur as one model for studying fracture repair. The external fixator consisted of two aluminum blocks connected by two rods. Four pins are used to connect the blocks to the bone. Mechanical characterization of the fixators was carried out prior to their use. Sixty‐two wild type mice with bilateral femoral fractures were created using an open technique and fixed using the fixator. The progress of fracture healing was monitored radiologically before sacrifice and by mechanical testing and histology after sacrifice. Initially four mice died intraoperatively from excessive blood loss, the intraoperative mortality was subsequently reduced by subcutaneous saline infusion. The bone healed between 14 and 21 days after fracture and remodeled by 60 days. Both radiological and mechanical assessments showed a steady progression of bone healing. Histology demonstrated callus and endochondral bone formation. This study demonstrated that it is possible to create a mouse femoral fracture model stabilized by external fixation and will provide an additional model to the understanding of fracture healing in transgenic and knockout mice. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Recombinant osteogenic protein‐1 upregulates extracellular matrix metabolism by rabbit annulus fibrosus and nucleus pulposus cells cultured in alginate beads
Authors: Masuda K. , Takegami K. , An H. , Kumano F. , Chiba K. , Andersson G. B. J. , Schmid T. , Thonar E. 
Published: March 2003

AbstractThis study was performed to determine if recombinant human osteogenic protein‐1 (rhOP‐1) is effective in promoting matrix synthesis and matrix formation by rabbit nucleus pulposus (NP) and annulus fibrosus (AF) cells cultured in alginate beads. The effects of culturing the cells in the presence of various concentrations of rhOP‐1 were assessed by measuring changes in cell proliferation, proteoglycan (PG) and collagen synthesis and mRNA expression, and in the matrix contents of PG and collagen, as indicators of matrix accumulation. At high concentrations, rhOP‐1 had a moderate mitogenic effect on both NP and AF cells. It also stimulated the synthesis of PG and collagen in a dose‐dependent manner: this was associated with a corresponding increase in the expression of mRNA for aggrecan core protein and collagen type II. The stimulatory effect of rhOP‐1 on PG synthesis was more pronounced than that on collagen synthesis. Continuous treatment with rhOP‐1 led to an increase in the total DNA, PG and collagen contents in both NP and AF cultures. The results presented here provide evidence of the ability of rhOP‐1 to stimulate the metabolism of both rabbit AF and NP cells cultured in alginate beads. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Regulatory role of E‐NTPase/NTPDase in fat/CD36‐mediated fatty acid uptake
Authors: Kannan Subburaj 
Published: March 2003

AbstractFatty acid translocase (FAT)/CD36‐mediated long‐chain fatty acid uptake in human umbilical vessel endothelial cells is associated with as yet uncharacterized translocase activity. The molecular mechanism of its function is not yet understood. Numerous attempts to purify rat cardiac sarcolemmal E‐NTPase (an integral membrane protein also referred to as ecto‐Ca2+/Mg2+ATPase) have revealed a complete amino acid sequence identity for FAT/CD36 protein. The most striking observation is that purified CD36 from human platelets shows significant E‐NTPase activity. In view of recent progress in understanding CD36 functional properties, an attempt is made in this article to illustrate the point that association of E‐NTPase (possibly extracellular Ca2+/Mg2+nucleotide triphosphate diphosphohydrolase) activity with CD36 may be of potential functional significance.
Sequence of a conserved region of a new sea urchin homeobox gene from the NKfamily
Authors: Smolenicka Zuzana , Pani Filippo , Hwang Kae‐Jung , Gruschus James M , Ferretti James A 
Published: March 2003

AbstractThe partial sequence of a novel homeobox‐containing gene from Paracentrotus lividus is described. Both cDNA and genomic DNA were screened using probes from the vnd/NK‐2 homeobox gene found in Drosophila melanogaster. The new DNA sequence found in P. lividus encodes a protein fragment that is closely related to the NK family of homeodomain transcriptional regulators originally discovered in the fruit fly. This study thus represents the first finding of a homeobox gene from the NK family in sea urchin. The DNA that was sequenced includes the most highly conserved region of the NK genes and contains the 180 base pair homeobox (i.e. the DNA segment that encodes the homeodomain), the NK‐2 box that encodes the NK‐2‐specific domain (NK‐2 SD), and the acidic box that encodes an acidic domain, but which is found only in a limited subset of the NK genes. In this deduced sequence, the 60 amino acid residue homeodomain contains tyrosine in position 54 and leucine in position 7, which implies that the protein will bind to an unusual sequence of DNA that contains 5′‐CAAGTG‐3′ as its core. The presence of tyrosine in position 54 identifies the gene as a member of the NK‐2 class of homeobox genes. Positions 37 and 56 of the homeodomain contain isoleucine and leucine, respectively, which is the first finding in the NK family of homeodomains of these particular amino acid residues in those positions. The presence of the NK‐2 box is consistent with identification of the gene as a member of the NK‐2 class, and suggests an important role for the C‐terminal portion of the protein in transcriptional activation. The sequence homology of the NK‐2 box and the spacing between it and the homeobox further suggest that this gene is a member of the NKx‐2.2 subclass, whose genes typically are expressed in brain and play a role in axonal guidance, and whose full lengths often are of the order of 900 bases. Homologous NK genes have been found in such diverse invertebrate and vertebrate species, such as Amphioxus sp., Xenopus sp., Caenorhabditis elegans, zebra fish, chicken, hamster, mouse and humans. The finding of this new gene together with sequence comparisons suggests possible evolutionary relationships between sea urchins and vertebrates in the developmental pathways of their body plans.
Altered calcium transient and development of hypertrophy in β2‐adrenoceptor overexpressing mice with and without pressure overload
Authors: Schwarz Bettina , Percy Elodie , Gao Xiao‐Ming , Dart Anthony M. , Richardt Gert , Du Xiao‐Jun 
Published: March 2003

AbstractTransgenic (TG) mice with cardiac specific 200‐fold overexpression of β2‐adrenoceptors (β2‐AR) have a facilitated development of heart failure following thoracic aortic constriction (TAC). We have studied the alterations of intracellular Ca2+ transients and myocyte size in wild‐type (WT) and TG mice after TAC. Cardiomyocytes were isolated from mice 9 weeks after TAC or sham operation, and incubated with Fura 2/AM. The Ca2+ transients were determined by Spex dual wavelength Spectrometer during electrical stimulation. The cell size was also determined planimetrically. Cells of sham operated TG mice displayed higher systolic Ca2+ amplitude than respective WT group (ΔF340/F380 ratio: 1.05±0.08 vs. 0.63±0.05; P<0.01), a finding in keeping with enhanced ventricular contractility in the TG mice. However, hypertrophied and failing myocytes of TG animals showed a fall in Ca2+ transients from sham‐operated control levels and there was no difference between TG and WT groups following TAC. In sham‐operated groups, the cell size of TG mice was significantly bigger than in WT animals (3212±139 vs. 2605±162 μm2; P<0.05). The cell size increased to a similar extent in both groups after TAC (4715±216 vs. 5027±365 μm2, P=n.s.). In summary, hypertrophy of cardiomyocytes was present in β2‐AR TG mice under baseline conditions. A further hypertrophy occurred during pressure overload to an extent similar to that in WT animals. However, the increased intracellular Ca2+ transient, seen in sham‐operated TG mice, was no longer detectable following development of severe hypertrophy and heart failure. These findings provide explanation on the lack of hemodynamic benefit in β2‐AR TG mice subjected to pressure overload.
Hypoxia, angiotensin‐II, and norepinephrine mediated apoptosis is stimulus specific in canine failed cardiomyocytes: a role for p38 MAPK, Fas‐L and cyclin D1
Authors: Sharov Victor G. , Todor Anastassia , Suzuki George , Morita Hideaki , Tanhehco Elaine J. , Sabbah Hani N. 
Published: March 2003

AbstractBackground:Apoptosis may contribute to the myocardial dysfunction associated with heart failure (HF). Activation of the p38 MAPK cascade can induce apoptosis in non‐cardiac cells through increased expression of Fas‐L, or through decreased expression of cyclin D1.Aims:We tested the hypothesis that hypoxia (HX), angiotensin‐II (A‐II) and norepinephrine (NEPI) can mediate apoptosis by activating p38 MAPK, and thus initiating stimulus specific changes in Fas‐L and cyclin D1 expression in failing cardiomyocytes.Methods and results:Cardiomyocytes isolated from ten dogs with HF induced by coronary microembolizations were subjected to HX or A‐II or NEPI with and without a p38 MAPK inhibitor (SB 203580). TUNEL staining for DNA fragmentation and Western blots for p38 MAPK, Fas‐L and cyclin D1 detection were performed. HX‐induced apoptosis was associated with increased Fas‐L expression, A‐II‐induced apoptosis was associated with increased Fas‐L and decreased cyclin D1 expression, and NEPI‐induced apoptosis was associated with decreased cyclin D1 expression. Inhibition of p38 MAPK activity attenuated stress‐induced apoptosis in all experiments and reversed changes in Fas‐L and cyclin D1 expression.Conclusions:HX, A‐II and NEPI mediate apoptosis in failing cardiomyocytes via different effects on Fas‐L and cyclin D1 expression. Inhibition of p38 MAPK reversed these effects, suggesting that apoptosis induced by HX, A‐II and NEPI involves activation of p38 MAPK upstream from Fas‐L and cyclin D1.
The heme-heme oxygenase system: a molecular switch in wound healing
Authors: Wagener Frank A. D. T. G. , van Beurden Hugo E. , von den Hoff Johannes W. , Adema Gosse J. , Figdor Carl G. 
Published: March 2003

AbstractWhen cells are injured they release their contents, resulting in a local accumulation of free heme proteins and heme. Here, we investigated the involvement of heme and its degrading enzyme heme oxygenase (HO) in the inflammatory process during wound healing. We observed that heme directly accumulates at the edges of the wound after inflicting a wound in the palate of Wistar rats. This coincided with an increased adhesion molecule expression and the recruitment of leukocytes. To prove that heme is responsible for the recruitment of leukocytes, heme was administered intradermally 24 hours prior to injury. A clear heme-induced influx of both macrophages and granulocytes was observed. When examining the HO isoforms, HO-1 and HO-2, we found that HO-2 was present in the entire submucosa. Surprisingly, we observed also that HO-1 is significantly expressed in the epithelium of both the mucosa and the skin of animals without wounds. On inflammation, HO-1 expression increased, particularly in infiltrating cells during the resolution phase of inflammation. Interestingly, we observed that heme-induced influx of leukocytes was highly elevated after pharmacologic inhibition of HO activity. These observations suggest that the heme-HO system is closely involved in the control of wound healing. Our results demonstrate that the local release of heme may be a physiologic trigger to start inflammatory processes, whereas HO-1 antagonizes inflammation by attenuating adhesive interactions and cellular infiltration. Moreover, the basal level of HO expression in the skin may serve as a first protective environment against acute oxidative and inflammatory insults.
Genetically targeted radiotherapy for multiple myeloma
Authors: Dingli David , Diaz Rosa Maria , Bergert Elizabeth R. , O'Connor Michael K. , Morris John C. , Russell Stephen J. 
Published: March 2003

AbstractMultiple myeloma is a disseminated neoplasm of terminally differentiated plasma cells that is incurable with currently available therapies. Although the disease is radiosensitive, external beam radiation leads to significant toxicity due to sensitive end-organ damage. Thus, genetic approaches for therapy are required. We hypothesized that the incorporation of immunoglobulin promoter and enhancer elements in a self-inactivating (SIN) lentiviral vector should lead to specific and high-level transgene expression in myeloma cells. A SIN lentivector with enhanced green fluorescent protein (EGFP) expression under the control of a minimal immunoglobulin promoter as well as the Kappa light chain intronic and 3′ enhancers transduced myeloma cell lines with high efficiency (30%-90%). EGFP was expressed at a high level in myeloma cells but silent in all nonmyeloma cell lines tested compared with the cytomegalovirus (CMV) promoter/enhancer. Transduction of myeloma cells with the targeted vector coding for the human sodiumiodide symporter (hNIS) led to hNIS expression by these cells allowing them to concentrate radioiodine up to 18-fold compared with controls. Tumor xenografts in severe combined immunodeficiency mice expressing hNIS could be imaged using iodine-123 (123I) and shown to retain iodide for up to 48 hours. These tumor xenografts were completely eradicated by a single dose of the therapeutic isotope iodine-131 (131I) without evidence of recurrence up to 5 months after therapy. We conclude that lentivectors can be transcriptionally targeted for myeloma cells and the use of hNIS as a therapeutic gene for myeloma in combination with 131I needs further exploration.
Melphalan-mobilized blood stem cell components contain minimal clonotypic myeloma cell contamination
Authors: Zhou Ping , Zhang Yana , Martinez Carmen , Kalakonda Nagesh , Nimer Stephen D. , Comenzo Raymond L. 
Published: March 2003

AbstractOptimal methods of stem cell mobilization in multiple myeloma are undefined, and contaminating clonotypic cells could contribute to disease recurrence. A phase 2 trial of intravenous melphalan (60 mg/m2) and granulocyte colony-stimulating factor (G-CSF) (10 μg/kg/d) for mobilization was performed. To enhance reliability, contamination was assessed with 2 sensitive methods, immunoglobulin light and heavy chain variable region patient-specific limiting-dilution polymerase chain reaction (PCR). We evaluated 29 stem cell components (SCCs) from 15 patients; for 9 SCCs, only VL PCR was used because of light chain disease or technical problems with VH primers. For 20 SCCs, VL and VH PCR results were highly correlated (r2 = 0.93, P &lt; .01), with 35% (7 of 20) having identical estimates. VH PCR gave significantly higher estimates for 8—and VL PCR for 5—SCCs, supporting the utility of using 2 methods. Estimated clonotypic contamination per SCC was 0.0009% (range, 0%-0.1%) or 0.5 × 104 clonotypic cells per kilogram (range, 0-41.2 × 104/kg), and contamination correlated with CD34+ cells collected (r2 = 0.42, P &lt; .01). Melphalan-mobilized SCCs contain minimal clonotypic contamination.
Transgenic delivery of VEGF to mouse skin leads to an inflammatory condition resembling human psoriasis
Authors: Xia Yu-Ping , Li Baosheng , Hylton Donna , Detmar Michael , Yancopoulos George D. , Rudge John S. 
Published: March 2003

Abstract
Gene therapy approaches involving vascular endothelial growth factor (VEGF) to promote therapeutic angiogenesis are under consideration for conditions ranging from ischemic heart disease to nonhealing skin ulcers. Here we make the surprising observation that the transgenic delivery of VEGF to the skin results in a profound inflammatory skin condition with many of the cellular and molecular features of psoriasis, including the characteristic vascular changes, epidermal alterations, and inflammatory infiltrates. Even longstanding psoriatic disease remains dependent on the transgenic VEGF in this model because it can be effectively reversed by the addition of VEGF Trap, a potent VEGF antagonist. Previous attempts to faithfully replicate the psoriatic phenotype through the transgenic delivery of epidermal keratinocyte growth factors or inflammatory mediators generated phenotypes with only partial resemblance to human psoriasis, leaving unanswered questions about the etiology of this disease. The ability of transgenic VEGF to induce a psoriasiform phenotype suggests a new etiology and treatment approach for this disease and further substantiates emerging concerns about possible proinflammatory adverse effects that might be associated with therapeutic attempts to deliver VEGF. (Blood. 2003;102:161-168)