bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk assessment of p53 genotypes and haplotypes in tobacco‐associated leukoplakia and oral cancer patients from eastern india
Authors: Mitra Sayan , Sikdar Nilabja , Misra Chaitali , Gupta Shalini , Paul Ranjan Rashmi , Roy Bidyut , Panda Chinmay Kumar , Roychoudhury Susanta 
Published: June 2005

AbstractThe role of 3 p53 polymorphisms (16 bp duplication at intron 3, codon 72 Arg/Pro and intron 6 NciI RFLP at np 13494) as potential markers for indicating cancer risk remains inconclusive. In our case‐control study consisting of 197 leukoplakia and 310 oral squamous cell carcinoma (SCC) patients and 348 controls, genotype frequencies at these 3 p53 loci were determined by PCR‐RFLP method and analyzed by multiple logistic regression to determine the risks of the diseases. The 2/2 genotype at codon 72 of p53 was at risk for developing leukoplakia (OR = 1.6, 95% CI 1.1–2.3), whereas the combination of 1/2 and 2/2 genotypes at intron 3 and 1/1 and 1/2 genotypes at intron 6 conferred a protective effect against leukoplakia and oral SCC development, respectively (OR = 0.5, 95% CI 0.4–0.8 and OR = 0.6, 95% CI 0.5–0.9, respectively). When subjects were stratified according to specific tobacco habit, the risk/protection estimates improved significantly in some cases. Specifically, the exclusive smokers with p53 codon 72 2/2 genotype showed a higher risk of developing leukoplakia (OR = 2.7, 95% CI 1.2–6.3). Furthermore, a particular p53 haplotype 1‐2‐2 was at risk for both tobacco‐associated leukoplakia and oral SCC (OR = 1.5, 95% CI 1.1–1.9 and OR = 1.3, 95% CI 1.1–1.7, respectively). Our results show that both specific p53 genotype and haplotype can indicate risk of tobacco‐associated leukoplakia, but risk of development of tobacco‐associated oral SCC can be predicted by specific p53 haplotype only. © 2005 Wiley‐Liss, Inc.
Clinical significance of CXCR3 and CXCR4 expression in primary melanoma
Authors: Longo‐Imedio M. Isabel , Longo Natividad , Treviño Isabel , Lázaro Pablo , Sánchez‐Mateos Paloma 
Published: June 2005

AbstractTumor cell migration involved in metastases is a tightly regulated, nonrandom process. Chemokines have been identified as critical molecules guiding cell migration. We performed a prospective study to analyze a possible association between the expression of chemokine receptors CXCR3 and CXCR4 by primary melanoma and clinical outcome. Forty primary melanomas were available for analysis; 57% of the tumors expressed CXCR3 and 35% expressed CXCR4 by melanoma cells. At initial diagnosis, 5 patients had subclinical lymph node involvement and after a median follow‐up time of 32 months, 2 additional patients developed regional lymph node metastases and 5 patients developed distant metastases. The expression of CXCR4, but not CXCR3, by melanoma cells in primary lesions was significantly associated with the presence of ulceration, increased tumor thickness, a greater risk of developing regional and distant metastases and a higher mortality rate. Our study underscores the value of CXCR4 expression as a useful marker for predicting outcome in patients with localized melanoma. In addition, our findings support that, among chemokine receptors, CXCR4 might be an appropriate therapeutic target for adjuvant therapy in patients at risk for metastatic disease. © 2005 Wiley‐Liss, Inc.
Dual‐specificity phosphatase 1 and serum/glucocorticoid‐regulated kinase are downregulated in prostate cancer
Authors: Rauhala Hanna E. , Porkka Kati P. , Tolonen Teemu T. , Martikainen Paula M. , Tammela Teuvo L.J. , Visakorpi Tapio 
Published: June 2005

AbstractInactivation of tumor suppressor genes through deletion, mutation and epigenetic silencing has been shown to occur in cancer. In our study, we combined DNA demethylation and histone deacetylation inhibition treatments with suppression subtraction hybridization (SSH) and cDNA microarrays to identify potentially epigenetically downregulated genes in PC‐3 prostate cancer cell line. We found 11 genes whose expression was upregulated after relieving epigenetic regulation. Expression of 3 genes [dual‐specificity phosphatase 1 (DUSP1), serum/glucocorticoid regulated kinase (SGK) and spermidine/spermine N1‐acetyltransferase (SAT)] was subsequently studied in clinical sample material using real‐time quantitative RT‐PCR and immunohistochemistry. TheDUSP1andSGKmRNA expression was lower in hormone‐refractory prostate carcinomas compared to benign prostate hyperplasia (BPH) or untreated prostate carcinomas. BPH, normal prostate and high‐grade prostate intraepithelial neoplasia (PIN) expressed high levels of DUSP1 and SGK proteins. Ninety‐two percent and 48% of the prostate carcinomas showed almost complete lack of DUSP1 and SGK proteins, respectively, indicating common downregulation of these genes. The genomic bisulphite sequencing did not reveal dense hypermethylation in the promoter regions of eitherDUSP1orSGK. In conclusion, the data suggest that downregulation ofDUSP1andSGKis an early event and could be important in the tumorigenesis of prostate cancer. © 2005 Wiley‐Liss, Inc.
A novel osteotropic biomaterial OG‐PLG: Synthesis and in vitro release
Authors: Whang Kyumin , McDonald Jonathan , Khan Ambereen , Satsangi Neera 
Published: June 2005

AbstractStatins (e.g., simvastatin) have shown to induce expression of the bone morphogenic protein‐2 gene in bone cells, but they are not used clinically because of a lack of a suitable delivery device. The overall objective is to develop optimized statin delivery devices for bone regeneration. The specific objective was to determine the effect of grafting statins to biodegradable poly[lactide‐co‐glycolide] (PLG) on release kinetics. Simvastatin was grafted to PLG (OG‐PLG) and characterized using contact‐angle measurements, attenuated total reflectance–Fourier transform infrared, and ultraviolet–visible spectroscopy to determine success of the synthesis. An ultraviolet–visible assay for measuring release of statins and degraded OG‐PLG in media was also developed. In vitro release studies using films and scaffolds made with PLG, PLG blended with simvastatin (PLG + Sim), and OG‐PLG (simvastatin grafted to PLG) blended into PLG at different concentrations showed that release rate of OG‐PLG from films was significantly greater than that of PLG + Sim. However, release rate from scaffolds showed PLG + Sim to be significantly higher than that of OG‐PLG. The diffusion‐controlled release kinetics of simvastatin from PLG + Sim seems to be more heavily affected by device morphology, whereas the degradation‐controlled release kinetics seem to be less affected. In short, release kinetics can be modulated by grafting statins to PLG. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Composite prostheses used to repair abdominal wall defects: Physical or chemical adhesion barriers?
Authors: Bellón J. M. , Serrano N. , Rodríguez M. , García‐Honduvilla N. , Pascual G. , Buján J. 
Published: June 2005

AbstractIn a composite prosthesis, the component placed at the peritoneal interface takes the form of a physical or chemical barrier. In this experimental study performed on the white New Zealand rabbit, several composites were examined to establish the effectiveness of these barriers at impeding adhesion formation. The biomaterials tested were two polypropylene prostheses (PP) with the physical barriers of expanded polytetrafluoroethylene or polyurethane (PP + ePTFE and PP + PU) and two prostheses (one polyester and the other PP) with the absorbable chemical barriers of polyethylene glycol/glycerol and hyaluronate, respectively (PO + gl and PP + hy). The composites were used to repair 7 × 5 cm defects created in the abdominal wall of the animals by placing the implant in contact with the visceral peritoneum and the subcutaneous tissue and fixing it to recipient tissue by 4/0 polypropylene running suture. Fourteen days after surgery the animals were sacrificed and specimens were taken for light microscopy and scanning electron microscopy. Adhesions developing at the prosthesis/visceral peritoneal interface were quantified. All the prostheses induced optimal mesothelialization. Composites with physical barriers behaved similarly in terms of provoking adhesions. However, the prostheses with chemical barriers differed in their effectiveness at preventing adhesions. Overall, the best results were obtained with the PP + PU composite. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Antimicrobial activity and tightness of a DCPD–CaO‐based hydraulic calcium phosphate cement for root canal filling
Authors: Michaïlesco Pierre , Kouassi Michel , El Briak Hasna , Armynot Anne , Boudeville Philippe 
Published: June 2005

AbstractCalcium hydroxide is currently used in dentistry for endodontic treatments where its main advantage is its antibacterial and anti‐inflammatory activity. However, it also has some drawbacks such as pulp necrosis, slight solubility, slow and insufficient hardening, and retraction on drying. In consequence, it is used only as temporary material for root canal disinfection. By mixing calcium hydrogen phosphate dihydrate (CaHPO4 · 2H2O, also called dicalcium phosphate dihydrate, DCPD) and calcium oxide with a sodium phosphate buffer as liquid phase, we obtained a CPC with better mechanical properties than calcium hydroxide pastes. The setting reaction produced either hydroxyapatite (HA) or a mixture of HA and calcium hydroxide depending on the relative masses of DCPD and CaO in the cement powder. The presence of calcium hydroxide a priori confers antimicrobial properties to this cement which were investigated in agar plates (diffusion method) against Streptococcus mutans, Lactobacillus acidophilus, Candida albicans, Enterococcus faecalis, Staphylococcus hominis (clinical isolates), and a preparation of polymicrobial flora isolated from dental plaque. The cement samples tested were prepared at molar calcium‐to‐phosphate ratios (Ca/P) of 1.67 to 2.75. A pure calcium hydroxide paste was used as reference material. Clear and reproducible bacterial growth inhibition was observed for cement samples with Ca/P ≥ 2 against all the microorganisms tested. With Ca/P = 2.5, this cement alkalinizes dentinal tubules and provides a fluid‐tight sealing that well compares with sealing obtained using a zinc oxide–eugenol cement without gutta‐percha point. DCPD–CaO‐based cement is therefore a potential root canal filler. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
The contradictory effects of pores on fatigue cracking of bone cement
Authors: Janssen Dennis , Aquarius René , Stolk Jan , Verdonschot Nico 
Published: June 2005

AbstractThe beneficial effect of porosity reduction on the fatigue life of bone cement has been demonstrated in numerous experimental studies. Clinically, however, it seems that the beneficial effect of porosity reduction of cement around total hip replacement components can only be found in large follow‐up studies. Little is known about the actual mechanical effect of a pore on fatigue crack formation in cement mantles. We studied the effect of pores on the crack formation process in a finite element model of a transverse slice of a total hip reconstruction. We created models with a single large pore and models with multiple pores at levels of 2, 4, and 9%. The models were cyclically torque‐loaded, causing macrocracks to appear in the cement mantle. In all models, we found that pores acted as microcrack initiators. However, pores could have both a detrimental and a beneficial effect on the macrocrack propagation in the cement mantle. Both effects were seen in the models with a single large pore and in the models with multiple pores. Pores would either accelerate, deviate, or decelerate the macrocrack propagation in the cement mantle. The effect of the pores depended on the location of the pores with respect to the stress intensities in the model, but was independent of the pore size or the level of porosity. The results may explain why the beneficial effect of vacuum mixing is difficult to demonstrate clinically. Stress intensities that are present in a cement mantle in an in vivo situation may overshadow the detrimental effect of a pore, while the beneficial effect may become more pronounced. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Three‐dimensional printing of porous ceramic scaffolds for bone tissue engineering
Authors: Seitz Hermann , Rieder Wolfgang , Irsen Stephan , Leukers Barbara , Tille Carsten 
Published: June 2005

AbstractThis article reports a new process chain for custom‐made three‐dimensional (3D) porous ceramic scaffolds for bone replacement with fully interconnected channel network for the repair of osseous defects from trauma or disease. Rapid prototyping and especially 3D printing is well suited to generate complex‐shaped porous ceramic matrices directly from powder materials. Anatomical information obtained from a patient can be used to design the implant for a target defect. In the 3D printing technique, a box filled with ceramic powder is printed with a polymer‐based binder solution layer by layer. Powder is bonded in wetted regions. Unglued powder can be removed and a ceramic green body remains. We use a modified hydroxyapatite (HA) powder for the fabrication of 3D printed scaffolds due to the safety of HA as biocompatible implantable material and efficacy for bone regeneration. The printed ceramic green bodies are consolidated at a temperature of 1250°C in a high temperature furnace in ambient air. The polymeric binder is pyrolysed during sintering. The resulting scaffolds can be used in tissue engineering of bone implants using patient‐derived cells that are seeded onto the scaffolds.This article describes the process chain, beginning from data preparation to 3D printing tests and finally sintering of the scaffold. Prototypes were successfully manufactured and characterized. It was demonstrated that it is possible to manufacture parts with inner channels with a dimension down to 450 μm and wall structures with a thickness down to 330 μm. The mechanical strength of dense test parts is up to 22 MPa. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
The role of graft materials in suture augmentation for tendon repairs and reattachment
Authors: Kummer Frederick J. , Iesaka Kazuho 
Published: June 2005

AbstractVarious biomaterials have been used to augment sutures for the repair and reattachment of tendons. This study examined four different graft materials in a simple and reproducible model using chicken Achilles tendons to determine the strength and mechanism of suture reinforcement of tendon repairs. The graft materials tested were Gore‐Tex® Soft Tissue Patch, Graftjacket™, bovine pericardium, and an experimental graft material from Xylos Corporation. Testing was performed in shear to simulate forces on a torn tendon repair and pull‐off to simulate those on a tendon reattachment to bone. Compared to unaugmented suture, grafts increased suture fixation strength from 10% to 60% in shear and from 0% to 36% in pull‐off with the bovine pericardium graft, providing significant improvement in both tests. In no cases (even unaugmented) did the suture pull directly through the tendon, but instead sliced along it, demonstrating that the interface between the suture and the tendon determines fixation strength. Grafts function by increasing the area, friction, and nature of this interface, not by acting as a barrier for suture pull‐through. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Three‐dimensional tomography of composite fracture surfaces
Authors: Drummond James L. , De Carlo Francesco , Super Boaz J. 
Published: June 2005

AbstractThe goal of this project was to image the three‐dimensional fracture interface of a dental composite with the use of X‐ray tomography. With the use of the Advanced Photon Source (APS) at Argonne National Laboratory, three‐dimensional images were obtained of the crack interface of a dental composite material that had been subjected to three different treatments: a control, cycled in air, and cycled in a 50/50 mixture by volume of ethanol and distilled water. The cycle‐loaded treatments were for 100,000 cycles at a load between 80 and 100 N at 5 Hz. The crack interface extended over 28 slices for the control, 96 for the air‐cycled specimen, and 83 slices for the 50/50 solution cycle specimen. It would appear that the fatiguing of the specimens allowed for an increase in the crack interface as demonstrated by the 3D tomographical analysis. This volume increase in the crack interface is attributed to a separation of the filler fiber from the resin matrix. Three‐dimensional tomography provides an excellent method to observe crack interfaces of dental composites subjected to different types of mechanical and environmental conditions. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Histology and ultrastructure of a tissue‐engineered collagen meniscus before and after implantation
Authors: Reguzzoni Marcella , Manelli Alessandro , Ronga Mario , Raspanti Mario , Grassi Federico A. 
Published: June 2005

AbstractThe collagen meniscus implant (CMI) is a tissue‐engineering technique designed to stimulate regeneration of meniscus‐like tissue in cases of irreparable tears or previous meniscectomy. CMI morphology was investigated before and after implantation by light microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In a case series biopsy specimens were harvested from four patients who underwent a second arthroscopic look 6 months after placement of the CMI. CMI sections appeared composed of parallel connective laminae of 10–30 μm, connected by smaller bundles (5–10 μm). This connective network formed lacunae with diameters between 40 and 60 μm. At greater magnification, the walls of the lacunae demonstrated tightly packed and randomly distributed collagen fibrils, with diameters ranging from 73 to 439 nm. In the biopsy specimens, the lacunae were filled with connective tissue that contained newly formed vessels and fibroblast‐like cells, presenting an abundant rough endoplasmic reticulum and several mitochondria. In the extracellular matrix, the collagen fibrils showed uniform diameters (126 nm ± 32 nm). The original structure of CMI was still recognizable, and no inflammatory cells were detected within the implant. The morphological findings of this case series demonstrate that CMI provides a three‐dimensional scaffold suitable for colonization by precursor cells and vessels and leading to the formation of a fully functional tissue. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
The preparation and characteristics of a carbonated hydroxyapatite/collagen composite at room temperature
Authors: Liao Susan , Watari Fumio , Uo Motohiro , Ohkawa Shoji , Tamura Kazuchika , Wang Wei , Cui Fuzhai 
Published: June 2005

AbstractNanocarbonated hydroxyapatite/collagen (nCHAC) composite was prepared at room temperature via biomimetic self‐assembly method. X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) were performed. This composite shows the same inorganic phase of natural bone with nanosized level and low degree of crystallinity, and contains 2.8–14.7 wt % of carbonated content. TEM results confirm that the microstructure of this composite is the mineralized collagen fiber bundle like the hierarchical structure of natural bone. The diameter of a single mineralized collagen fiber is about 4 nm. Slightly different assembly units of the composite with different carbonates and collagen were demonstrated. The carbonated percentage affects the mineral crystal size and collagen fibril assembly. Because of the biomimetic component and microstructure, the use of nCHAC composite is promising for hard tissue therapy. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Energetic and topological analyses of the oxidation reaction between Mon (n = 1, 2) and N2O
Authors: Michelini Maria Del Carmen , Russo Nino , Alikhani Mohammad Esmaïl , Silvi Bernard 
Published: June 2005

AbstractThe interaction between molybdenum, atom, and dimer, with nitrous oxide has been investigated using density functional theory. The analysis of the potential energy surfaces for both reactions has revealed that a single molybdenum atom can activate the NO bond of N2O requiring a small activation energy. However, the presence of several intersystem crossings between three different spin states, namely, septet, quintet and triplet states, seems to be the major constraint to the Mo + N2O reaction. Contrarily, the low‐lying excited states (triplet and quintet) do not participate in the reaction between the molybdenum dimer and N2O. The latter reaction fully evolves on the singlet spin surface. Three different regions have been distinguished along the pathway: formation of an adduct complex, formation of an inserted compound, and the N2 detachment. The connection between the two first regions has been characterized by the formation of a special complex in which the NO bond is so weakened that it could be considered as a first step in the insertion process. It has been shown that the topological changes along the pathways provide a clear explanation for the geometrical changes that occur along the reaction pathway. In summary, the detachment of the N2 molecule is found to be kinetically an effective process for both reactions, owing to the high exothermicity and consequently to the high internal energy of the insertion intermediates. However, in the case of Mo atom, the reaction should be a slow process due to the presence of spin‐forbidden transitions. These results fully agree with previous experimental works. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1284–1293, 2005