bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical Study of Polycaprolactone-hydroxyapatite Porous Scaffolds Created by Porogen-based Solid Freeform Fabrication Method
Authors: Lu Lin , Zhang Qingwei , Wootton David M. , Chiou Richard , Li Dichen , Lu Bingheng , Lelkes Peter I. , Zhou Jack 
Published: November 2014

Materials and Methods Polycaprolactone (PCL) and polycaprolactone-hydroxyapatite (PCL-HA) scaffolds with 600-μm pore size were fabricated by drop-on-demand printing (DDP) structured porogen method followed with injection molding. Specimens with special dimensions of 4.2×4.2×5.4 mm3 and 6.6×6.6×13.8 mm3 were designed and fabricated for compression and tensile tests, respectively. The mechanical study was performed on both solid and porous PCL and PCL-HA samples. The effect on mechanical properties of the HA content ratio in PCL-HA composites was investigated. Results Porous scaffold made of 80/20 PCL-HA composite had an ultimate compressive strength of 3.7±0.2 MPa and compression modulus of 61.4±3.4 MPa, which is in the range of reported trabecular bone's compressive strength. Increasing the concentration of HA in the composites raised compressive properties and stiffness significantly (P<0.05), which demonstrates that PCL-HA composites have the potential for application in bone regeneration. Tensile test of solid PCL and PCL-HA composites showed that the ultimate tensile strength and tensile modulus increased with increases of the concentration of HA in the composites. The tensile test was also conducted on PCL porous scaffold; the result indicated that the scaffold was slightly softer and weaker in tension compared with compression. Conclusions Combining compression and tensile test results, our study may guide the possible application of these biomaterials in bone tissue engineering and support further development of microstructure-based models of scaffold mechanical properties.
Structural Behavior of Human Lumbar Intervertebral Disc under Direct Shear
Authors: Schmidt Hendrik , Häußler Kim , Wilke Hans-Joachim , Wolfram Uwe 
Published: November 2014

Purpose The intervertebral disc (IVD) is a complex, flexible joint between adjacent vertebral bodies that provides load transmission while permitting movements of the spinal column. Finite element models can be used to help clarify why and how IVDs fail or degenerate. To do so, it is of importance to validate those models against controllable experiments. Due to missing experimental data, shear properties are not used thus far in validating finite element models. This study aimed to investigate the structural shear properties of human lumbar IVDs in posteroanterior (PA) and laterolateral (LL) loading directions. Methods Fourteen lumbar IVDs (median age: 49 years) underwent direct shear in PA and LL loading directions. A custom-build shear device was used in combination with a materials testing machine to load the specimens until failure. Shear stiffness, ultimate shear force and displacement, and work to failure were determined. Results Each specimen was tested until complete or partial disruption. Median stiffness in PA direction was 490 N/mm and in LL direction 568 N/mm. Median ultimate shear force in the PA direction was 2,877 N and in the LL direction 3,199 N. Work to failure was 12 Nm in the PA and 9 Nm in the LL direction. Conclusions This study was an experiment to subject IVDs to direct shear. The results could help us to understand the structure and function of IVDs with regard to mechanical spinal stability, and they can be used to validate finite element models of the IVD.
Enamel Structural Changes induced by Hydrochloric and Phosphoric Acid Treatment
Authors: Bertacci Angelica , Lucchese Alessandra , Taddei Paola , Gherlone Enrico F. , Chersoni Stefano 
Published: November 2014

Purpose The aim of this study was to evaluate enamel acid-induced structural changes after 2 different treatments, by means of Raman and infrared (IR) spectroscopy analyses, and to correlate these findings with permeability measured as fluid discharge from outer enamel. Methods Two different treatments were investigated: 10 enamel slices were etched with 15% hydrochloric acid (HCl) for 120 seconds and 10 slices with 37% phosphoric acid gel (H3PO4) for 30 seconds, rinsed for 30 seconds and then air-dried for 20 seconds. Powders of enamel treated as previously described were produced. Replicas of enamel subjected to the same treatments were obtained to evaluate the presence of fluid droplets on enamel surface. Results and Conclusions Raman and IR spectroscopy showed that the treatment with both hydrochloric and phosphoric acids induced a decrease in the carbonate content of the enamel apatite. At the same time, both acids induced the formation of HPO42- ions. After H3PO4 treatment, the bands due to the organic component of enamel decreased in intensity, while they increased after HCl treatment. Replicas of H3PO4 treated enamel showed a strongly reduced permeability. Replicas of HCl 15% treated samples showed a maintained permeability. A decrease of the enamel organic component, as resulted after H3PO4 treatment, involves a decrease in enamel permeability, while the increase of the organic matter (achieved by HCl treatment) still maintains enamel permeability. The results suggested a correlation between organic matter and enamel permeability. Permeability was affected by etching technique and could be involved in marginal seal, gap and discoloration at the enamel interface, still causes of restoration failure.
Thermal Isotherms in PMMA and Cell Necrosis during Total Hip Arthroplasty
Authors: Gundapaneni Dinesh , Goswami Tarun 
Published: November 2014

Background Polymethylmethacrylate (PMMA), also known as bone cement, is a commonly used adhesive material to fix implants in Total Hip Arthroplasty (THA). During implantation, bone cement undergoes a polymerization reaction which is an exothermic reaction and results in the release of heat to the surrounding bone tissue, which ultimately leads to thermal necrosis. Necrosis in the bony tissue results in early loosening of the implant, which causes pain and reduces the life of the implant. Purpose The main objective of the present study was to understand the thermal isotherms in PMMA and to determine the optimal cement mantle thickness to prevent cell necrosis during THA. Methods In this study, the environment in the bony tissue during implantation was simulated by constructing 3D solid models to observe the temperature distribution in the bony tissue at different cement mantle thicknesses (1 mm, 3 mm and 5 mm), by applying the temperature conditions that exist during the surgery. Stems made with Co-Cr-Mo, 316L stainless steel and Ti6Al4V were used, which acted as heat sinks, and a thermal damage equation was used to measure the bone damage. FEA was conducted based on temperature conditions and thermal isotherms at different cement mantle thicknesses were obtained. Results Thermal isotherms derived with respect to distance in the bony tissue from the center of the cement mantle, and cell necrosis was determined at different mantle thicknesses. Based on the deduced results, cement mantle thickness of 1-5 mm does not cause thermal damage in the bony tissue. Conclusion Considering the long term stability of the implant, cement mantle thickness range from 3 mm-5 mm was found to be optimal in THA to prevent cell necrosis.
Biomechanical Properties: Effects of Low-level Laser Therapy and Biosilicate® on Tibial Bone Defects in Osteopenic Rats
Authors: Fangel Renan , Bossini Paulo S. , Renno Ana Cláudia , Granito Renata N. , Wang Charles C. , Nonaka Keico O. , Driusso Patricia , Parizotto Nivaldo A. , Oishi Jorge 
Published: November 2014

Purpose The aim of this study was to investigate the effects of laser therapy and Biosilicate® on the biomechanical properties of bone callus in osteopenic rats. Methods Fifty female Wistar rats were equally divided into 5 groups (n=10/group): osteopenic rats with intact tibiae (SC); osteopenic rats with unfilled and untreated tibial bone defects (OC); osteopenic rats whose bone defects were treated with Biosilicate® (B); osteopenic rats whose bone defects were treated with 830-nm laser, at 120 J/cm2 (L120) and osteopenic rats whose bone defects were treated with Biosilicate® and 830-nm laser, at 120 J/cm2 (BL120). Ovariectomy (OVX) was used to induce osteopenia. A non-critical bone defect was created on the tibia of the osteopenic animals 8 weeks after OVX. In Biosilicate® groups, bone defects were completely filled with the biomaterial. For the laser therapy, an 830-nm laser, 120 J/cm2 was used. On day 14 postsurgery, rats were euthanized, and tibiae were removed for biomechanical analysis. Results Maximal load and energy absorption were higher in groups B and BL120, according to the indentation test. Animals submitted to low-level laser therapy (LLLT) did not show any significant biomechanical improvement, but the association between Biosilicate® and LLLT was shown to be efficient to enhance callus biomechanical properties. Conversely, no differences were found between study groups in the bending test. Conclusions Biosilicate® alone or in association with low level laser therapy improves biomechanical properties of tibial bone callus in osteopenic rats.
Activation of EGFR Signaling from Pilocytic Astrocytomas to Glioblastomas
Authors: Carvalho Priscila O. , Uno Miyuki , Oba-Shinjo Sueli M. , Rosemberg Sergio , Wakamatsu Alda , da Silva Clemar C. , Teixeira Manoel J. , Marie Suely K. N. 
Published: November 2014

Introduction EGFR analyses allow for better correlation between genotype and phenotype in astrocytomas and represent an attractive therapeutic target. Most studies emphasize analyses of EGFR in glioblastomas (GBMs) but do not analyze all grades of astrocytomas (from pilocytic to GBM). The purpose of our study was to evaluate the status of EGFR (expression, deletion, and amplification) and EGFR protein expression in all grades of astrocytomas. Patients and Methods We analyzed a total of 145 surgical tumor specimens that included: 22 pilocytic astrocytomas, 22 grade II astrocytomas, 17 grade III astrocytomas and 84 GBMs. The specimens were compared to 17 non-neoplastic brain tissues obtained from epilepsy surgery. EGFR expression, EGFR amplification and EGFRvIII analyses were performed by quantitative real-time PCR, and protein expression was evaluated by immunohistochemistry. Results EGFR relative overexpression and EGFR amplification were observed, respectively, in 50% and 20% of astrocytomas, while EGFRvIII was only found in GBMs (34.5%, p=0.005). Amongst EGFR-amplified GBM cases, 59% also presented EGFRvIII (p<0.001). Cytoplasmic accumulation of EGFR protein was detected in 75% of astrocytomas, and 21% of the astrocytomas showed nuclear localization (p=0.003). Conclusions EGFR alterations were found in all grades of astrocytomas, from pilocytic to GBMs, while EGFRvIII was exclusively found in GBMs. These findings provide important information on the mechanisms involved in the progression of astrocytomas for determining whether EGFR status can be used for effective and specific therapy.
Clinicopathological and Prognostic Value of S100A4 Expression in Gastric Cancer: A Meta-Analysis
Authors: Ling Zhian , Li Ruolin 
Published: November 2014

Purposes For several years S100A4 has been implicated in tumor progression and prognosis. However, the prognostic value of S100A4 overexpression in patients with gastric cancer remains unknown. Therefore, we performed a meta-analysis to assess the relationship between S100A4 overexpression and clinical outcome of gastric cancer. Methods and Results Candidate studies were searched from PubMed, Embase, Cochrane Library, and ISI Web of Science. We included studies that evaluated the prognostic value of S100A4 expression in gastric cancer patients with regard to survival and a series of clinicopathological parameters. The pooled hazard ratios (HR) and odds ratios (OR) with 95% confidence intervals (CI) were used to estimate the effects. Ten studies, all from Asia, were included in the meta-analysis. The pooled analysis showed that S100A4 overexpression was significantly associated with worse overall survival (OS) (HR=1.86, 95% CI: 1.45-2.38, p<0.00001) without heterogeneity in the data (I2=43.6%, p=0.131). Furthermore, our results showed that S100A4 overexpression was significantly correlated with some clinicopathological parameters such as tumor grade, stage, metastasis, invasion, and relapse. Conclusions The results of our meta-analysis indicate that S100A4 overexpression correlates with more adverse clinical features and a poor prognosis of gastric cancer patients in Asia, thus suggesting that S100A4 could be a useful marker to evaluate progression and prognosis of Asian gastric cancer patients. More studies from Western countries with a larger number of tumors and standardized methods are required before significant conclusions can be drawn.
Prognostic Significance of microRNA-221/222 Expression in Cancers: Evidence from 1,204 Subjects
Authors: Wang Jin , Liu Sha , Sun Guo Ping , Wang Fang , Zou Yan Feng , Jiao Yang , Ning Jie , Xu Jing 
Published: November 2014

Background The prognostic significance of the expression of the miR-221/222 family in cancer remains controversial. We here performed a meta-analysis of published data investigating the effects of miR-221/222 expression on both overall survival (OS) and disease-free survival (DFS) among patients with cancer. Methods A systematic search of the PubMed, Embase, Cochrane, and CNKI databases was performed with the last search being updated on March 15, 2013. The hazard ratio (HR) and its 95% confidence interval (95% CI) were used to assess the strength of association. Results A total of 17 studies involving 1,204 subjects were included in this meta-analysis. When assessing the prognostic significance of miR-221 expression, the pooled HR was 1.91 (95% CI: 1.28-2.85, p=0.002) for OS and 1.36 (95% CI: 0.88-2.09, p=0.163) for DFS. When assessing the prognostic significance of miR-222 expression, the pooled HR was 2.15 (95% CI: 1.51-3.06, p<0.0001) for OS and 1.37 (95% CI: 0.45-4.13, p=0.581) for DFS. We also found that an elevated miR-221 expression was significantly associated with poor OS when stratifying by ethnicity, cancer type, statistical methodology, sample, and quality assessment. There was no evidence of publication bias. Conclusion The meta-analysis demonstrates that the elevated expression of miR-221 and miR-222 is associated with poor OS in patients with cancer. The miR-221/222 cluster might be used as a potential therapeutic strategy in clinical practice. More work is required to fully elucidate the role of the miR-221/222 family in human tumors.
Association between SNPs in P53 Binding Regions and Risk of Esophageal Squamous Cell Carcinoma
Authors: Wang Kai , Liu Botao , Li Juan , Xiong Gang , Guan Xingying , Yang Kang , Bai Yun 
Published: November 2014

Background The tumor protein 53 (TP53 or p53) plays an important role in tumor suppression by binding to the regulatory region of its target genes. Single nucleotide polymorphisms (SNP) located in the p53 binding regions are likely to affect the expression of p53 target genes and may contribute to susceptibility to common diseases. The role of the genetic variations in esophageal squamous cell carcinoma (ESCC) has been well explored. However, the role of p53 binding region variations in esophageal cancer is poorly understood. Methods We investigated the association of 6 p53 binding region polymorphisms with susceptibility of 400 ESCC cases and 400 cancer-free controls in a Southwest Chinese population using the SNapShot assay. Differences in frequencies of the SPNs genotypes between cases and controls were evaluated using the chi-square test. Results We found that the C allele of rs1009316 in Bax and rs762624 in CDKN1A can decrease the risk of ESCC. In the multiple genetic model, we found that the rs2395655 in CDKN1A is related with the risk of ESCC, and that the G allele increases the susceptibility to ESCC (OR: 1.364; 95% CI: 1.104-1.685). We carried out a stratification analysis between alleles and risk of ESCC according to clinical stage. There was no relationship between these SNPs and clinical stage. Conclusion SNPs in the p53 binding region may modulate the risk of ESCC in the Southwest Chinese population.
Rising CEA Levels in a Patient with Colon Carcinoma: Metachronous Medullary Thyroid Cancer
Authors: Göksu Sema Sezgin , Göksu Uğur A. , Gündüz Seyda , Coşkun Hasan S. 
Published: November 2014

Introduction Carcinoembryonic antigen (CEA) is a commonly used tumor marker, and its value in colon cancer is well established. However it is overexpressed in many different tumors. Here we report a case of colorectal cancer with high postoperative CEA levels that were associated with medullary thyroid carcinoma. Case A 60-year old man was operated for colon cancer. Postoperative CEA level was 107.6 ng/mL, while preoperative CEA level was unknown. For the detection of distant metastasis or local recurrence, we performed 18-flouro deoxyglycose (FDG) positron emission tomography (PET) and computed tomography (CT). We observed an increased FDG accumulation in the right lobe of the thyroid. The patient had cystic and non-metabolic lesions in the liver, and started a treatment with FOLFOX regimen. After 3 months of chemotherapy CEA was still as high as 146 ng/mL. There was no pathologic FDG uptake other than the thyroid nodule in PET-CT. Fine needle aspiration of the thyroid nodule revealed a follicular neoplasia. The patient underwent total thyroidectomy and histopathology revealed a medullary thyroid carcinoma. Postoperative CEA levels then lowered to normal ranges. Conclusion The case we here report was a stage III colorectal cancer with high CEA levels. Our focus on searching a residual/metastatic disease made us blind to other possible explanations; in fact, none of us noticed the thyroid nodule. This case reminds us not to forget that high CEA levels can be associated with conditions other than colon cancer, such as thyroid medullary carcinoma.
Resistin -420C>G Promoter Variant and Colorectal Cancer Risk
Authors: Mahmoudi Touraj , Karimi Khatoon , Arkani Maral , Farahani Hamid , Vahedi Mohsen , Dabiri Reza , Nobakht Hossein , Asadi Asadollah , Mirakhorli Mojgan , Arshi Benafsheh , Derakhshan Arash , Zali Mohammad Reza 
Published: November 2014

Purposes Obesity is associated with an increased risk of colorectal cancer (CRC), and ghrelin (GHRL) and resistin (RETN) are thought to be related to obesity. Our aim was to investigate whether GHRL and RETN gene variants are associated with CRC risk. Materials and Methods All 414 subjects, including 197 cases with CRC and 217 controls, were genotyped for the GHRL (rs26802) and RETN (rs1862513) or -420C>G gene variants using the PCR-RFLP method. Results Our findings indicated that the RETN -420C>G “CC” genotype, compared with the “GG” and “GC” genotypes, was a marker of decreased CRC susceptibility; the difference remained significant after adjustment for age, BMI, gender, smoking status, NSAID use, and family history of CRC (p=0.020; OR=0.52, 95% CI=0.30-0.90). Furthermore, after adjustment for confounding factors, the -420C>G “CC” genotype, compared with the “GG” genotype, was associated with a decreased risk for CRC (p=0.044; OR=0.53, 95% CI=0.29-0.98). In addition, no significant difference was observed for the GHRL (rs26802) gene variant. Conclusions To our knowledge, this is the first study suggesting that the RETN -420C>G “CC” genotype is a marker of decreased CRC susceptibility. This observation is relevant from a scientific perspective and deserves further investigations.
Prognostic Value of Microvessel Density in Hepatocellular Carcinoma Patients: A Meta-Analysis
Authors: Li Yanyan , Ma Xuelei , Zhang Jing , Liu Xiaoxiao , Liu Lei 
Published: November 2014

Introduction The identification of microvessel density (MVD) in patients suffering from different types of cancer has become a hot point as an emerging and promising biomarker. The aim of the present study is to clarify the prognostic relevance of MVD in hepatocellular carcinoma (HCC). Methods Relevant articles were screened in PubMed and EMBASE databases. Patients' clinical characteristics, overall survival (OS), disease/recurrence-free survival (DFS/RFS), and MVD levels were extracted for further analysis. The statistical analysis derived from the Kaplan—Meier survival curves was calculated indirectly with the methods developed by Parmar, Williamson, and Tierney. Multivariate Cox hazard regression analysis was used directly in Stata 11.0. The pooled hazard ratio (HR) and 95% confidence interval (CI) were calculated to evaluate the prognostic role of MVD in HCC. Results Our online literature search identified 12 articles including a total of 1,138 HCC patients. Meta-analysis of all the included studies considering survival outcomes showed a positive correlation between poor prognosis and higher-MVD levels. The pooled HRs (and 95% CIs) for OS and DFS/RFS were respectively 2.08 [1.77-2.45] and 2.64 [2.12-3.29]. Subgroup analyses considering tumor stage (I-II/III-IV), tumor size (<5 cm/≥5 cm), differentiation (well/poor), or cirrhosis status (≥20%/<20%) were also conducted, and all the above analyses supported the prognostic role of MVD in HCC. Conclusion Our meta-analysis showed that the available evidence supports the proposition that MVD has a good predictive role in HCC, especially when the patients have late stage, large size, or poorly differentiated tumors.
HER2 as a Predictive Factor for Successful Neoadjuvant Anthracycline Chemotherapy of Locally Advanced and Early Breast Cancer
Authors: Wang Jiayu , Xu Binghe , Yuan Peng , Li Qing , Zhang Pin , Cai Ruigang , Ma Fei , Fan Ying , Luo Yang 
Published: November 2014

Objective The aim of this study was to look for predictive and prognostic factors in anthracycline-based neoadjuvant chemotherapy. Methods Three hundred and nine patients with early-stage or locally advanced breast cancer were enrolled in this study and preoperatively treated with neoadjuvant chemotherapies in intense dose-dense (cyclophosphamide + epirubicin) or conventional (paclitaxel + epirubicin) regimens. Outcome parameters included overall objective response rate, as well as factors for determining pathological features influencing the efficacy of chemotherapy, such as estrogen receptor, progesterone receptor, and HER2 status, Eastern Cooperative Oncology Group (ECOG) score, tumor size, tumor inflammation, and lymph node metastasis. Results The overall pathological complete response (pCR) rate was 14.3%, and the main factor affecting the efficacy of chemotherapy was HER2 expression. The pCR rate was significantly higher for patients with HER2 overexpression, compared with patients with low HER2 expression (27.5% vs. 9.6%, p<0.001). The recurrence risk for patients with pCR decreased 1.12-fold compared with patients without pCR (5-year disease-free survival [DFS]: 81.8% vs. 65.7%, p=0.038). Patients in the HER2 overexpression subgroup benefited more from pCR than those in the HER2 low expression group (5-year DFS: 86.4% vs. 62.1%, p=0.049). Conclusion HER2 overexpression in primary tumors might be a predictive marker for good efficacy of anthracycline-based neoadjuvant chemotherapy. The pCR is a suitable prognostic factor, even for patients with HER2 overexpression.