bluuebunny/crossref_metadata_2025_split huggingface dataset:
Platelet‐derived growth factor in human glioma
Authors: Westermark Bengt , Heldin Carl‐Henrik , Nistér Monica 
Published: May 2005

AbstractPlatelet‐derived growth factor (PDGF) is a 30 kDa protein consisting of disulfide‐bonded dimers of A‐ and B‐chains. PDGF receptors are of two types, α‐ and β‐receptors, which are members of the protein‐tyrosine kinase family of receptors. The receptors are activated by ligand‐induced dimerization, whereby the receptors become phosphorylated on tyrosine residues. These form attachment sites for signalling molecules, which inter alia activate the Ras · Raf pathway. PDGF has important functions in development and is required for a proper timing of oligodendrocyte differentiation. The v‐sis oncogene of simian sarcoma virus (SSV) is a retroviral homolog of the B‐chain gene, and induces transformation by an autocrine activation of PDGF receptors at the cell surface. SSV induces malignant glioma in experimental animals, suggesting a role for autocrine PDGF in glioma development. PDGF and PDGF receptors are frequently coexpressed in human glioma cell lines. Specific and nonspecific PDGF antagonists block the growth of some glioma cell lines in vitro and in vivo, suggesting that autocrine PDGF is involved in transformation and tumorigenesis. In situ studies of human gliomas show overexpression of α‐receptors in glioma cells of high‐grade tumors. In a few cases, overexpression is caused by receptor amplification. Since high‐grade glioma cells also express the PDGF A‐chain, an autocrine activation of the α‐receptor may drive the proliferation of glioma cells in vivo. © 1995 Wiley‐Liss, Inc.
Cytokines and tumors of the central nervous system
Authors: Van Meir Erwin G. 
Published: May 2005

AbstractCytokines are a group of molecules with an extremely broad range of activities on a variety of target cells. This review summarizes the known cytokine and cytokine receptor expression in primary brain tumors and derived cell lines. These expression patterns are compared with those occurring in other CNS diseases, such as virus or bacterial infections, experimental allergic encephalitis, multiple sclerosis, and trauma. A variety of cytokines are expressed during CNS neoplasia; their potential involvement in tumor growth through a variety of mechanisms, such as autocrine or paracrine growth stimulation, angiogenesis, and immune surveillance evasion, are discussed. Finally, results of preliminary therapeutic approaches with cytokines are critically evaluated. © 1995 Wiley‐Liss, Inc.
Neurofibromatosis type 2 and von Hippel‐Lindau disease: From gene cloning to function
Authors: Kley Nikolai , Whaley Jean , Seizinger Bernd R. 
Published: May 2005

AbstractMost of the genes for hereditary tumor syndromes cloned thus far have subsequently been shown to be mutated not only in the germlines and tumors from patients with the relatively rare inherited disease, but also in the much more common sporadic tumor counterparts in the general population. Thus, the isolation and functional characterization of genes associated with hereditary tumor syndromes have emerged as a major strategy to gain insights into some of the most fundamental mechanisms of tumorigenesis.The search for the genes causing two hereditary tumor syndromes of the nervous system, neurofibromatosis type 2 (NF2) and von Hippel‐Lindau disease (VHL), has recently culminated in the cloning of both disease genes. This represents another successful application of the so‐called positional cloning approach, i.e., the isolation of a hereditary disease gene with unknown function, based on the determination of its chromosomal location in the human genome.The gene for NF2, a syndrome typically associated with vestibular schwannomas and meningiomas, is homologous with a family of genes whose members appear to play an important role in bridging the cell membrane with the intracellular cytoskeleton, including moesin, ezrin, radixin, and protein 4.1. Recent mutation analyses have revealed that the NF2 tumor suppressor gene is frequently mutated not only in vestibular schwannomas and meningiomas from NF2 patients, but also in their sporadic counterparts, which represent approximately one‐third of all human brain tumors. Furthermore, malignant human tumors seemingly unrelated to the NF2 syndrome, such as neural crest‐derived malignant melanomas, as well as malignant mesotheliomas (a pleural mesoderm‐derived tumor), have also been found to be frequently mutated or deleted in the NF2 locus, suggesting a broader role for the NF2 gene in the initiation and progression of human neoplasms.VHL is a rare tumor syndrome characterized by certain types of nervous system tumors (cerebellar and spinal hemangioblastomas as well as retinal angiomas), in conjunction with bilateral renal cell carcinomas and pheochromocytomas. Similar to NF2, recent genetic mutation studies have revealed that the VHL tumor suppressor gene is not only mutated in the hereditary tumors from VHL patients, but also in their sporadic counterparts. Importantly, the VHL gene represents the most frequently mutated cancer‐related gene thus far identified in sporadic renal cell carcinoma. In contrast to most other hereditary cancer syndromes, however, VHL mutations are surprisingly specific for tumors typically associated with the VHL syndrome, and have not been detected in any other tumor type unrelated to VHL.The cloning and initial genetic characterization of the NF2 and VHL genes have now provided a rational basis for subsequent functional studies on the elucidation of the normal and tumor‐associated cellular signaling pathways of these tumor suppressor genes. © 1995 Wiley‐Liss, Inc.
Molecular pathways in the formation of gliomas
Authors: von Deimling Andreas , Louis David N. , Wiestler Otmar D. 
Published: May 2005

AbstractThe past few years have seen remarkable progress in understanding the molecular genetic basis of glioma formation. Affected oncogenes and tumor suppressor genes have been identified and putative tumor suppressor loci have been mapped. These studies have illustrated distinct molecular pathways for different glial neoplasms. We summarize the findings of an ongoing study initiated to characterize human gliomas on a molecular basis. The data are compiled from 150 astrocytic, oligodendroglial, and mixed gliomas that were assessed for genomic alterations characteristic of these neoplasms, i.e., loss of portions of chromosomes 1p, 9p, 10, 17p, 17q, and 19q, mutations of the p53 tumor suppressor gene, and amplification of the EGF receptor (EGFR) gene. Our findings support the hypothesis that distinct genetic pathways result in the formation of astrocytic and oligodendroglial neoplasms of different malignancy grades, and that glioblastoma multiforme may be subdivided into genetically distinct subsets. Such findings may not only lead to a better understanding of neoplastic transformation in glial cells, but may also have a major impact on clinical neuro‐oncology. © 1995 Wiley‐Liss, Inc.
Angiogenesis in malignant gliomas
Authors: Plate Karl H. , Risau Werner 
Published: May 2005

AbstractOne event that accompanies glioma progression is the upregulation of angiogenesis. Low‐grade gliomas are moderately vascularized tumors whereas high‐grade gliomas show prominent microvascular proliferations and areas of high vascular density. To analyze the molecular mechanisms underlying glioma angiogenesis, we studied the expression of vascular endothelial growth factor (VEGF) and its tyrosine kinase receptors VEGFR‐1 and VEGFR‐2 during normal brain development and glioma‐induced angiogenesis. Our results suggest a paracrine control of angiogenesis and endothelial cell proliferation that is tightly regulated and transient in the embryonic brain, switched off in the normal adult brain, and turned on in tumor cells (VEGF) and the host vasculature (VEGFR‐1 and −2) during tumor progression. It is unknown how VEGF and VEGF receptors are upregulated during glioma angiogenesis, but there is recent evidence that VEGF as well as endogenous inhibitors of angiogenesis could be under control of the tumor suppressor genes p53 and VHL. © 1995 Wiley‐Liss, Inc.
Transgenic and gene disruption techniques in the study of neurocarcinogenesis
Authors: Aguzzi Adriano , Brandner Sebastian , Isenmann Stefan , Steinbach Joachim P. , Sure Ulrich 
Published: May 2005

AbstractTransgenic technologies have come of age, and the field of carcinogenesis has profited extensively from the availability of these methods. Both the inappropriate expression of dominant oncogenes in specific tissues and the ability to “knock out” tumor suppressor genes in mammalian organisms have enabled substantial advancements of our understanding of development and progression of the neoplastic phenotype. In the first part of this article, we review the most popular techniques for modification of the mammalian genome in vivo, i.e. microinjection of fertilized eggs, retrovirus‐mediated gene transfer, and targeted gene deletion through homologous recombination. Subsequently, we attempt a critical evaluation of the available models of neurocarcinogenesis, and discuss their impact and future potential for the study of cancer in the nervous system. © 1995 Wiley‐Liss, Inc.
Daily Cannabis Smoking as a Risk Factor for Progression of Fibrosis in Chronic Hepatitis C *
Authors: Hézode Christophe , Roudot-Thoraval Françoise , Nguyen Son , Grenard Pascale , Julien Boris , Zafrani Elie-Serge , Pawlostky Jean-Michel , Dhumeaux Daniel , Lotersztajn Sophie , Mallat Ariane 
Published: May 2005

Abstract

Cannabinoids present in

Cannabis sativa

(marijuana) exert biological effects via cannabinoid receptors CB1 and CB2. We recently demonstrated that CB1 and CB2 receptors regulate progression of experimental liver fibrosis. We therefore investigated the impact of cannabis smoking on fibrosis progression rate in patients with chronic hepatitis C (CHC). Two hundred seventy consecutive untreated patients with CHC of known duration undergoing liver biopsy were studied. Demographic, epidemiological, metabolic, and virological data were recorded, and detailed histories of cannabis, alcohol, and tobacco use over the span of hepatitis C virus infection were obtained. Fibrosis stage, steatosis, and activity grades were scored according to Metavir system. Patients were categorized as noncannabis users (52.2%), occasional users (14.8%), or daily users (33.0%), and the relationship between cannabis use and fibrosis progression rate (FPR) or fibrosis stage was assessed. On multivariate analysis, six factors were independently related to a FPR greater than 0.074 (median value of the cohort): daily cannabis use (OR = 3.4 [1.5-7.4]), Metavir activity grade A2 or higher (OR = 5.4 [2.9-10.3]), age at contamination of more than 40 years (OR = 10.5 [3.0-37.1]), genotype 3 (OR = 3.4 [1.5-7.7]), excessive alcohol intake (OR = 2.2 [1.1-4.5]), and steatosis (OR = 2.0 [1.0-4.1]). Daily cannabis use was also an independent predictor of a rapid FPR (>0.15) (OR = 3.6 [1.5-7.5]). Finally, severe fibrosis (≥F3) was also predicted by daily cannabis use (OR = 2.5 [1.1-5.6];

P

= .034), independently of Metavir activity grade, excessive alcohol intake, age at liver biopsy, steatosis, and tobacco smoking.
In conclusion
, daily cannabis smoking is significantly associated with fibrosis progression during CHC. Patients with ongoing CHC should be advised to refrain from regular cannabis use. (Hepatology 2005;.)
Osteoblast interactions with calcium phosphate ceramics modified by coating with type I collagen
Authors: Brodie J. C. , Goldie E. , Connel G. , Merry J. , Grant M. H. 
Published: May 2005

AbstractComplications associated with the use of autogenous bone in the repair or replacement of tissue lost through injury or disease have driven the search for alternative sources of graft material. Bioceramics containing hydroxyapatite (HA), tricalcium phosphate (TCP), or composites that combine the best properties of both of these materials are among the principal candidates. In this study, we have investigated the in vitro proliferation, morphology, and viability of an immortalized rat osteoblast cell line cultured on HA, TCP, and composites of the two in the ratios 75:25 (H75), 50:50 (H50), and 25:75 (H25) for 28 days. The biocompatibility of each material was examined in the presence and absence of a collagen coating. With the exception of H50, cell proliferation, quantified by carboxyfluorescein fluorescence, was enhanced by collagen coating of all materials for the first 14 days, although at later time points cell numbers were unaffected. It is notable that the collagen coating was least stable on H50, the only material not to show enhancement of cell growth on coating. Confocal laser scanning microscopy confirmed that cell growth was more extensive on coated materials over the first 7–14 days in culture, and the development of cell extensions and bridges across the pores in the materials was observed. Results indicate that collagen coating of calcium phosphate ceramics may also increase their compatibility and osseointegration in vivo. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Bioactive hydroxyapatite coatings on polymer composites for orthopedic implants
Authors: Auclair‐Daigle C. , Bureau M. N. , Legoux J.‐G. , Yahia L'H. 
Published: May 2005

AbstractHydroxyapatite [HA, Ca10(PO4)6(OH)2] coatings on polymer composite substrates were investigated for their bioactivity and their physicochemical and mechanical characteristics. HA holds key characteristics for use in orthopedic applications, such as for coating of the femoral stem in a hip replacement device. The plasma‐spray technique was used to project HA onto a carbon fiber/polyamide 12 composite substrate. The resulting HA coatings exhibited mechanical adhesion as high as 23 MPa, depending on the surface treatment of the composite substrate. The purpose of this investigation was to evaluate the bioactivity of an HA‐coated composite substrate. HA‐ coated samples have been immerged in simulated body fluid (SBF) and maintained within a shaker bath for periods of 1, 7, 14, 21, and 28 days at 37°C. Scanning electron microscopy, energy dispersive X‐ray spectroscopy, and X‐ray diffraction techniques were performed on the samples before and after immersion into SBF. SBF was analyzed using inductively coupled plasma atomic emission spectrometry for element concentration and evaluation of the solution's purity. SBF conditioning led to the deposition of crystalline HA onto the surface of the coatings. The calcium‐to‐phosphorous ratios of initial HA coating and of newly deposited HA were respectively 1.72 and 1.65, close to the HA theoretical calcium/phosphorous value of 1.67. Results demonstrated that bioactive HA coatings were produced by plasma spraying, because SBF conditioning induced newly formed HA with high crystallinity. Mechanical adhesion of the HA coatings was not significantly affected upon SBF conditioning. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Autologous peripheral blood stem cell collections in children weighing less than 10 Kg with solid tumors: Experience of a single center
Authors: Cho Hyun‐Jung , Jung Hae‐Kyung , Sung Ki‐Woong , Ku Hong‐Hae , Lee Sue‐Hyun , Kim Dae‐Won 
Published: May 2005

AbstractThere have only been a few reports and limited performance of peripheral blood stem cell (PBSC) collection in very small children weighing less than 10 kg. In this study, we intended to evaluate the safety and yield of PBSC collection, with the efficacy of PBSC transplantation (PBSCT) in the smallest children with solid tumors. From January 1998 to February 2004, 173 children underwent PBSC collection in Samsung Medical Center, Korea. Of these, 15 (8.7%) children weighed less than 10 kg and their clinical diagnoses were neuroblastoma (10 cases), rhabdoid tumor (2 cases), rhabdomyosarcoma (2 cases), and Wilms tumor (1 case). PBSCs were collected following chemotherapy plus G‐CSF mobilization. The median age and weight at the time of apheresis were 15 months and 9 kg, respectively. The median number of PBSC collection procedures per case was 4 (range, 2–7). The median cell yield per apheresis product was 0.95 (range, 0.01–33.32) × 106/kg CD34+ cells and 1.96 (range, 0.12–23.39) × 108/kg mononuclear cells. No complications associated with citrate toxicity and other adverse effect were observed during the procedures. After high‐dose chemotherapy, 14 patients were reinfused with PBSCs alone and all showed successful hematopoietic recovery. We concluded that PBSC collection would be a safe and practical procedure, even when done in the smallest children, provided that adequate intravascular fluid volume and circulating red cell mass were maintained. Also, the use of PBSCs to support high‐dose chemotherapy was well tolerated and might enhance hematological recovery in the smallest children showing the excellent efficacy of PBSCT. J. Clin. Apheresis © 2005 Wiley‐Liss, Inc.
A case of non‐lethal pulmonary air embolism after leukapheresis catheter removal
Authors: Grífols Joan‐Ramon , Ferrà Christelle , Sancho Juan‐Manuel , Pujol Misericordia , Ribera Josep‐Maria 
Published: May 2005

AbstractMononuclear cell leukapheresis requires good‐quality venous access. Catheter placement and removal of the catheter may be associated with life‐threatening local or systemic complications. Thus, prompt recognition of these complications and appropriate therapy can be life‐saving. We report the case of a young man who presented with an air embolism following removal of a jugular venous catheter after peripheral blood stem cell collection. We have reviewed the signs and symptoms presented by the patient and the methodology used to remove the catheter. Catheter removal requires careful attention in order to avoid potentially serious complications. J. Clin. Apheresis © 2005 Wiley‐Liss, Inc.
Electrospray ionization mass and tandem mass spectra of a series of N‐pyrazolylmethyl and N‐triazolylmethyl N‐phenylpiperazines: new dopaminergic ligands with potential antipsychotic properties
Authors: Santos Leonardo S. , Padilha Monica Costa , de Aquino Neto Francisco Radler , Santos Pereira Alberto dos , Menegatti Ricardo , Manssour Fraga Carlos Alberto , Barreiro Eliezer J. , Eberlin Marcos N. 
Published: May 2005

AbstractRecently, two analogous series of N‐pyrazolylmethyl and N‐triazolylmethyl N‐phenylpiperazines have been prepared and found to be potential antipsychotic drugs acting as new selective ligands of the dopamine D2 receptor. Herein we report a systematic study of their high‐resolution electrospray ionization mass and tandem mass spectra in which the main dissociation routes of their protonated molecules are determined and rationalized. The ESI‐MS/MS data is very characteristic for both series allowing straightforward isomeric differentiation. A single and dominant fragment ion for the pyrazole series and four major fragment ions for the triazole series are useful for selective reaction MS monitoring of these potential drugs in biological fluids. Copyright © 2005 John Wiley & Sons, Ltd.
Analysis of parasitic quantum effects in classical CMOS circuits
Authors: Felgenhauer F. , Begoin M. , Mathis W. 
Published: May 2005

AbstractIn the mesoscopic regime, the MOS device performance is affected by gate‐induced quantization effects leading to a loss of transconductance and threshold voltage shift and gate leakage tunnelling currents degrading the overall device performance. We discuss the expected impact of quantum effects in highly down scaled CMOS circuits. Based on 1‐d numerical simulations for transport in mesoscopic systems, we set up Spice circuit models. The Spice models rebuild the influence of quantum effects; and the functionality of classical circuit concepts can be ‘tested’ in their robustness against these effects. A few circuit examples will be given. Copyright © 2005 John Wiley & Sons, Ltd.
Lymph node metastasis in an animal model: Effect of piecemeal laser surgical resection
Authors: Sapundzhiev Nikolay R. , Dünne Anja A. , Ramaswamy Annette , Sitter Helmut , Davis R. Kim , Werner Jochen A. 
Published: May 2005

AbstractBackground and ObjectivesEndoscopic laser surgical resection of advanced squamous cell carcinoma (SCC) often requires division of the tumor into several pieces. It is unknown if this approach influences the incidence of regional and distant metastases.Study Design/Materials and MethodsIn 143 rabbits VX2 SCC was induced. Eight days later the tumor was resected by two different methods. In the first group en bloc cold steel resection was performed. In the second group piecemeal laser resection was performed. On the 51th day the animals were sacrificed and examined for lymph node and distant metastases.ResultsAfter piecemeal laser resection 47.7% of the animals had lymph node metastases compared to 24.6% after en bloc resection (P = 0.01). The incidence of distant metastases did not differ for the two groups.ConclusionsIn our model narrow margin piecemeal laser resection was associated with a higher incidence of metastases compared to wide en bloc surgical resection. The exact mechanism responsible for this increase is unclear. © 2005 Wiley‐Liss, Inc.
Microgel‐Based Engineered Nanostructures and Their Applicability with Template‐Directed Layer‐by‐Layer Polyelectrolyte Assembly in Protein Encapsulation
Authors: Shenoy Dinesh B. , Sukhorukov Gleb B. 
Published: May 2005

AbstractSummary: A novel strategy for the fabrication of microcapsules is elaborated by employing biomacromolecules and a dissolvable template. Calcium carbonate (CaCO3) microparticles were used as sacrificial templates for the two‐step deposition of polyelectrolyte coatings by surface controlled precipitation (SCP) followed by the layer‐by‐layer (LbL) adsorption technique to form capsule shells. When sodium alginate was used for inner shell assembly, template decomposition with an acid resulted in simultaneous formation of microgel‐like structures due to calcium ion‐induced gelation. An extraction of the calcium after further LbL treatment resulted in microcapsules filled with the biopolymer. The hollow as well as the polymer‐filled polyelectrolyte capsules were characterized using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), and scanning force microscopy (SFM). The results demonstrated multiple functionalities of the CaCO3 core – as supporting template, porous core for increased polymer accommodation/immobilization, and as a source of shell‐hardening material. The LbL treatment of the core‐inner shell assembly resulted in further surface stabilization of the capsule wall and supplementation of a nanostructured diffusion barrier for encapsulated material. The polymer forming the inner shell governs the chemistry of the capsule interior and could be engineered to obtain a matrix for protein/drug encapsulation or immobilization. The outer shell could be used to precisely tune the properties of the capsule wall and exterior.Confocal laser scanning microscopy (CLSM) image of microcapsules (insert is after treating with rhodamine 6G to stain the capsule wall).magnified imageConfocal laser scanning microscopy (CLSM) image of microcapsules (insert is after treating with rhodamine 6G to stain the capsule wall).