bluuebunny/crossref_metadata_2025_split huggingface dataset:
Membrane Type 1 Matrix Metalloproteinase induces an epithelial to mesenchymal transition and cancer stem cell-like properties in SCC9 cells
Authors: Yang Cong-Chong , Zhu Li-Fang , Xu Xiao-Hui , Ning Tian-Yun , Ye Jin-Hai , Liu Lai-Kui 
Published: April 2013

Abstract

Background
Tissue invasion and metastasis are acquired abilities of cancer and related to the death in oral squamous cell carcinoma (OSCC). Emerging observations indicate that the epithelial-to-mesenchymal transition (EMT) is associated with tumor progression and the generation of cells with cancer stem cells (CSCs) properties. Membrane Type 1 Matrix Metalloproteinase (MT1-MMP) is a cell surface proteinase, which is involved in degrading extracellular matrix components that can promote tumor invasion and cell migration.

Methods
In the current study, we utilized SCC9 cells stably transfected with an empty vector (SCC9-N) or a vector encoding human MT1-MMP (SCC9-M) to study the role of MT1-MMP in EMT development.

Results
Upon up-regulation of MT1-MMP, SCC9-M cells underwent EMT, in which they presented a fibroblast-like phenotype and had a decreased expression of epithelial markers (E-cadherin, cytokeratin18 and β-catenin) and an increased expression of mesenchymal markers (vimentin and fibronectin). We further demonstrated that MT1-MMP-induced morphologic changes increased the level of Twist and ZEB, and were dependent on repressing the transcription of E-cadherin. These activities resulted in low adhesive, high invasive abilities of the SCC9-M cells. Furthermore, MT1-MMP-induced transformed cells exhibited cancer stem cell (CSC)-like characteristics, such as low proliferation, self-renewal ability, resistance to chemotherapeutic drugs and apoptosis, and expression of CSCs surface markers.

Conclusions
In conclusion, our study indicates that overexpression of MT1-MMP induces EMT and results in the acquisition of CSC-like properties in SCC9 cells. Our growing understanding of the mechanism regulating EMT may provide new targets against invasion and metastasis in OSCC.
Characterization of in vivo chemoresistant human hepatocellular carcinoma cells with transendothelial differentiation capacities
Authors: Marfels Christian , Hoehn Miriam , Wagner Ernst , Günther Michael 
Published: April 2013

Abstract

Background
Chemotherapeutic treatment of hepatocellular carcinoma often leads to chemoresistance during therapy or upon relapse of tumors. For the development of better treatments a better understanding of biochemical changes in the resistant tumors is needed. In this study, we focus on the characterization of in vivo chemoresistant human hepatocellular carcinoma HUH-REISO established from a metronomically cyclophosphamide (CPA) treated HUH7 xenograft model.

Methods
SCID mice bearing subcutaneous HUH7 tumors were treated i.p. with 75 mg/kg CPA every six days. Tumors were evaluated by immunohistochemistry, a functional blood-flow Hoechst dye assay, and qRT-PCR for ALDH-1, Notch-1, Notch-3, HES-1, Thy-1, Oct-4, Sox-2 and Nanog mRNA levels. Cell lines of these tumors were analyzed by qRT-PCR and in endothelial transdifferentiation studies on matrigel.

Results
HUH-REISO cells, although slightly more sensitive against activated CPA in vitro than parental HUH-7 cells, fully retained their in vivo CPA chemoresistance upon xenografting into SCID mice. Histochemical analysis of HUH-REISO tumors in comparison to parental HUH-7 cells and passaged HUH-PAS cells (in vivo passaged without chemotherapeutic pressure) revealed significant changes in host vascularization of tumors and especially in expression of the tumor-derived human endothelial marker gene PECAM-1/CD31 in HUH-REISO. In transdifferentiation studies with limited oxygen and metabolite diffusion, followed by a matrigel assay, only the chemoresistant HUH-REISO cells exhibited tube formation potential and expression of human endothelial markers ICAM-2 and PECAM-1/CD31. A comparative study on stemness and plasticity markers revealed upregulation of Thy-1, Oct-4, Sox-2 and Nanog in resistant xenografts. Under therapeutic pressure by CPA, tumors of HUH-PAS and HUH-REISO displayed regulations in Notch-1 and Notch-3 expression.

Conclusions
Chemoresistance of HUH-REISO was not manifested under standard in vitro but under in vivo conditions. HUH-REISO cells showed increased pluripotent capacities and the ability of transdifferentiation to endothelial like cells in vitro and in vivo. These cells expressed typical endothelial surface marker and functionality. Although the mechanism behind chemoresistance of HUH-REISO and involvement of plasticity remains to be clarified, we hypothesize that the observed Notch regulations and upregulation of stemness genes in resistant xenografts are involved in the observed cell plasticity.
Can the 12-item general health questionnaire be used to identify medical students who might ‘struggle’ on the medical course? A prospective study on two cohorts
Authors: James David , Yates Janet , Ferguson Eamonn 
Published: April 2013

Abstract

Background
Students who fail to thrive on the Nottingham undergraduate medical course frequently suffer from anxiety, depression or other mental health problems. These difficulties may be the cause, or the result of, academic struggling. Early detection of vulnerable students might direct pastoral care and remedial support to where it is needed. We investigated the use of the short-form General Health Questionnaire (GHQ-12) as a possible screening tool.

Methods
Two consecutive cohorts (2006 and 2007) were invited to complete the GHQ-12. The questionnaire was administered online, during the second semester (after semester 1 exams) for the 2006 cohort and during the first semester for the 2007 cohort. All data were held securely and confidentially. At the end of the course, GHQ scores were examined in relation to course progress.

Results
251 students entered the course in 2006 and 254 in 2007; 164 (65%) and 160 (63%), respectively, completed the GHQ-12. In both cohorts, the study and non-study groups were very similar in terms of pre-admission socio-demographic characteristics and overall course marks. In the 2006 study group, the GHQ Likert score obtained part-way through the first year was negatively correlated with exam marks during Years 1 and 2, but the average exam mark in semester 1 was the sole independent predictor of marks in semester 2 and Year 2. No correlations were found for the 2007 study group but the GHQ score was a weak positive predictor of marks in semester 2, with semester 1 average exam mark again being the strongest predictor. A post-hoc moderated-mediation analysis suggested that significant negative associations of GHQ scores with semester 1 and 2 exams applied only to those who completed the GHQ after their semester 1 exams. Students who were identified as GHQ ‘cases’ in the 2006 group were statistically less likely to complete the course on time (OR = 4.74, p 0.002). There was a non-significant trend in the same direction in the 2007 group.

Conclusions
Results from two cohorts provide insufficient evidence to recommend the routine use of the GHQ-12 as a screening tool. The timing of administration could have a critical influence on the results, and the theoretical and practical implications of this finding are discussed. Low marks in semester 1 examinations seem be the best single indicator of students at risk for subsequent poor performance.
Clinical utility of measuring expression levels of KAP1, TIMP1 and STC2 in peripheral blood of patients with gastric cancer
Authors: Wang Yuan-Yu , Li Li , Zhao Zhong-Sheng , Wang Hui-Ju 
Published: April 2013

Abstract

Background
We examined preoperative kinesin II-associated protein (KAP1), TIMP metallopeptidase inhibitor 1 (TIMP1) and stanniocalcin 2 (STC2) expression levels in patients with gastric cancers to assess their clinical application for diagnosing and monitoring diseases.

Methods
Real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of KAP1, TIMP1, STC2, talin 2 (TLN2), sushi-repeat-containing protein, X-linked 2 (SRPX2) and secreted protein, acidic, cysteine-rich (SPARC) in the patients’ peripheral blood karyocytes. The data were analyzed with receiver operating characteristics (ROC) curves.

Results
A total of 112 patients with gastric cancer, 42 patients with recurrence and 107 healthy volunteers were recruited. There were significant correlations between KAP1, TIMP1 and STC2 levels, and TNM tumor stages and distant metastases. The area under the ROC curves (AUC) of KAP1 was 0.803 ± 0.040 (P = 0.0001), the AUC of TIMP1 was 0.767 ± 0.043 (P = 0.0001) and the AUC of STC2 was 0.769 ± 0.045 (P = 0.0001), thus differentiating preoperative gastric cancer patients from healthy volunteers by ROC curve analysis. The AUC of STC2 was 0.739 ± 0.070 (P = 0.004) and the AUC of KAP1 was 0.418 ± 0.088 (P = 0.319), thus differentiating recurrence of gastric cancer from healthy volunteers by ROC curve analysis. High TIMP1 and STC2 expression levels were suspected to be poor prognostic factors of disease recurrence in patients with gastric cancer.

Conclusions

KAP1, TIMP1 and STC2 expression levels may be potential biomarkers for the screening, diagnosis, prognosis and surveillance of gastric cancer.
Metal-assisted chemical etching of Ge(100) surfaces in water toward nanoscale patterning
Authors: Kawase Tatsuya , Mura Atsushi , Dei Katsuya , Nishitani Keisuke , Kawai Kentaro , Uchikoshi Junichi , Morita Mizuho , Arima Kenta 
Published: April 2013

Abstract
We propose the metal-assisted chemical etching of Ge surfaces in water mediated by dissolved oxygen molecules (O2). First, we demonstrate that Ge surfaces around deposited metallic particles (Ag and Pt) are preferentially etched in water. When a Ge(100) surface is used, most etch pits are in the shape of inverted pyramids. The mechanism of this anisotropic etching is proposed to be the enhanced formation of soluble oxide (GeO2) around metals by the catalytic activity of metallic particles, reducing dissolved O2 in water to H2O molecules. Secondly, we apply this metal-assisted chemical etching to the nanoscale patterning of Ge in water using a cantilever probe in an atomic force microscopy setup. We investigate the dependences of probe material, dissolved oxygen concentration, and pressing force in water on the etched depth of Ge(100) surfaces. We find that the enhanced etching of Ge surfaces occurs only when both a metal-coated probe and saturated-dissolved-oxygen water are used. In this study, we present the possibility of a novel lithography method for Ge in which neither chemical solutions nor resist resins are needed.
Optimized maximum noise fraction for dimensionality reduction of Chinese HJ-1A hyperspectral data
Authors: Gao Lianru , Zhang Bing , Sun Xu , Li Shanshan , Du Qian , Wu Changshan 
Published: April 2013

Abstract
The important techniques in processing hyperspectral data acquired by interference imaging spectrometer onboard Small Satellite Constellation for Environment and Disaster mitigation (HJ-1A) are studied in this article. First, a new noise estimation method, named residual-scaled local standard deviations, is used to analyze the noise condition of HJ-1A hyperspectral images. Then, an optimized maximum noise fraction (OMNF) transform is proposed for dimensionality reduction of HJ-1A images, which adopts an accurately estimated noise covariance matrix for noise whitening. The proposed OMNF method is less sensitive to noise distribution and interference existence, thus it can more efficiently compact useful data information in a low-dimensional space. The proposed OMNF is evaluated through two applications, i.e., spectral unmixing and classification, using the HJ-1A image acquired at the Bohai Sea area in China. It demonstrates that the proposed OMNF provides better performance in comparison with other traditional dimensionality reduction methods.
Rhesus macaques vaccinated with consensus envelopes elicit partially protective immune responses against SHIV SF162p4 challenge
Authors: Eugene Hermancia S , Pierce-Paul Brooke R , Craigo Jodi K , Ross Ted M 
Published: April 2013

AbstractThe development of a preventative HIV/AIDS vaccine is challenging due to the diversity of viral genome sequences, especially in the viral envelope (Env160). Since it is not possible to directly match the vaccine strain to the vast number of circulating HIV-1 strains, it is necessary to develop an HIV-1 vaccine that can protect against a heterologous viral challenge. Previous studies from our group demonstrated that a mixture of wild type clade B Envgp160swere able to protect against a heterologous clade B challenge more effectively than a consensus clade B Envgp160vaccine. In order to broaden the immune response to other clades of HIV, in this study rhesus macaques were vaccinated with a polyvalent mixture of purified HIV-1 trimerized consensus Envgp140proteins representing clades A, B, C, and E. The elicited immune responses were compared to a single consensus Envgp140representing all isolates in group M (Con M). Both vaccines elicited anti- Envgp140IgG antibodies that bound an equal number of HIV-1 Envgp160proteins representing clades A, B and C. In addition, both vaccines elicited antibodies that neutralized the HIV-1SF162isolate. However, the vaccinated monkeys were not protected against SHIVSF162p4challenge. These results indicate that consensus Envgp160vaccines, administered as purified Envgp140trimers, elicit antibodies that bind to Envgp160sfrom strains representing multiple clades of HIV-1, but these vaccines did not protect against heterologous SHIV challenge.
Evaluation of inter-fraction and intra-fraction errors during volumetric modulated arc therapy in nasopharyngeal carcinoma patients
Authors: Yin Wen-Jing , Sun Ying , Chi Feng , Fang Jian-Lan , Guo Rui , Yu Xiao-Li , Mao Yan-Ping , Qi Zhen-Yu , Guo Ying , Liu Meng-Zhong , Ma Jun 
Published: April 2013

Abstract

Background
This prospective study was conducted to evaluate inter- and intra-fraction errors in nasopharyngeal carcinoma (NPC) patients undergoing volumetric modulated arc therapy (VMAT) using cone-beam computed tomography (CBCT) and to thus obtain planning target volume (PTV) margins to effectively guide treatment in the future.

Methods
Fifteen NPC patients scheduled to undergo VMAT were prospectively enrolled in the study. For each patient, three CBCT scans were obtained; one after daily conventional positioning, one after online correction with 2 mm tolerance and one after 1 week of VMAT delivery. The scans were registered to the planning CT to determine the inter- and intra-fraction errors. Patient positioning errors were analyzed for time trends over the course of radiotherapy. PTV margins were calculated from the systematic (Σ) and random (σ) errors.

Results
The average absolute values of the pre-correction, post-correction and intra-fraction errors (in order) were 1.1, 0.6 and 0.4 mm in the medial–lateral (ML) direction, 1.2, 0.7 and 0.5 mm in the superior–inferior (SI) direction and 1.1, 0.7 and 0.5 mm in the anterior–posterior (AP) direction. The corresponding Σ were 1.0–1.4 mm, 0.4–0.5 mm and 0.2–0.4 mm, while the corresponding σ were 0.7–0.8 mm, 0.6–0.7 mm and 0.5–0.6 mm. With time, gradual increases in both the inter- and intra-fraction three-dimensional displacements were observed (P = 0.019 and P = 0.044, respectively). The total PTV margins accounting for pre-correction and intra-fraction errors were 3.4–4.1 mm and those accounting for post-correction and intra-fraction errors were 1.7–2.2 mm.

Conclusions
CBCT is an effective modality to evaluate and improve the accuracy of VMAT in NPC patients. Inter- and intra-fraction three-dimensional displacements increased as a function of time during the course of radiotherapy. In our institution, we recommend a PTV margin of 5 mm for NPC patients undergoing VMAT without CBCT and 3 mm for those treated with rigorous daily CBCT scans.
Multi-analyte approach for determining the extraction of tobacco constituents from pouched snus by consumers during use
Authors: Digard Helena , Gale Nathan , Errington Graham , Peters Nicola , McAdam Kevin 
Published: April 2013

Abstract

Background
Snus is a smokeless oral tobacco product with a significant history of use in Sweden, where it is regulated under food legislation. Users place a small porous sachet or a pinch of loose snus between the upper jaw and cheek for approximately one hour, leading to partial intake of tobacco constituents. To understand user exposure to tobacco, a multi-analyte approach based on the extraction of pouches by methanol, ethanol and water was validated and applied to the measurement of various constituents, including nicotine, four tobacco-specific nitrosamines (TSNAs), propylene glycol, water, ammonium, nitrate, sodium, chloride, linalool, citronellol, linalyl acetate and geraniol, extracted from snus pouches during use by human consumers.

Results
After validation against established single-analyte methods, the multi-analyte approach was used to determine constituent levels in snus pouches before and after one hour of use. Although the concentrations in the snus pouches varied from nanogram (e.g. TSNAs) to milligram (e.g. nicotine, sodium and propylene glycol) quantities (25.1 ng to 35.3 mg per 1 g pouch), the mean percentage extracted varied only from 19.2% for linalyl acetate to 37.8% for the TSNA 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) among all constituents analyzed. The TSNAs, some of which are known carcinogens, showed the highest percentage extraction (range 34.6%–37.8%). Measurement variability was low for all analytes, ranging from 2.4% (total TSNAs, NAT) to 9.5% (geraniol). By contrast, inter-subject variability ranged from 6.7% (NAB) to 52.2% (linalyl acetate), and was greater than 20% for eight of the constituents analyzed. Intra-subject variability ranged from 3.4% (citronellol) to 29.7% (geraniol).

Conclusions
Generally, less than a third of each constituent tested was extracted during one hour of snus use, independent of constituent concentration. The variable nature of in-use extraction was shown to be driven by inter-subject variability. The results provide insight into possible mechanisms controlling constituent extraction in the mouth during snus use, and provide reference data for the development of in-vitro laboratory systems for estimating extraction of tobacco constituents from snus.
Contrast mimicking a subarachnoid hemorrhage after lumbar percutaneous epidural neuroplasty: a case report
Authors: Oh Chang Hyun , An Seong Dae , Choi Seung Hyun , Ji Gyu Yeul 
Published: April 2013

Abstract

Introduction
Subarachnoid hemorrhage is one of the most feared acute neurologic events. Accurate diagnosis of subarachnoid hemorrhage is essential, and computed tomography of the brain is the first diagnostic imaging study. However, in rare circumstances, a similar appearance may occur in the absence of blood in the subarachnoid space. The contrast enhancement of subarachnoid space is a rare complication after lumbar percutaneous epidural neuroplasty, with, to the best of our knowledge, no previous report in the literature.

Case presentation
A 42-year-old Korean male patient, who underwent a spinal operation five years previously at the level of L4 to S1, visited our clinic with persistent and aggravating low back pain. An imaging study revealed the focal and diffuse disc protrusion at the level of L4/5 and L5/S1. The clinician decided to perform a lumbar percutaneous epidural neuroplasty. During the procedure, dural adhesion was suspected at the previously operated level, and the neuroplasty catheter was malpositioned into the intradural space on the first attempt. After the catheter was repositioned, the scheduled epidural neuroplasty was completed. Our patient had no definite abnormal neurological signs. But, after a day, our patient complained of severe headache with sustained high blood pressure without neurological disorientation. Computed tomography of his brain showed a subarachnoid hemorrhage-like appearance with intracranial air. Sequential angiography, subtractional magnetic resonance imaging and examination of the cerebrospinal fluid revealed no abnormalities. Follow-up computed tomography after one day revealed no definite intracranial hemorrhage, and our patient was discharged with improved low back pain without neurological deficit.

Conclusion
We report a rare case of contrast mimicking a subarachnoid hemorrhage after lumbar percutaneous epidural neuroplasty. The physician should keep in mind a rare case like this, and the supine position with head elevation is necessary to avoid a similar complication after lumbar percutaneous epidural neuroplasty.
Multiple ileal perforations due to regular diclofenac sodium injections: a case report
Authors: Park Won Seok , Kim Sang Wook , Lee Seok , Lee Soo Teik , Park Ho Sung 
Published: April 2013

Abstract

Background
Although the adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the upper gastrointestinal tract have been well characterized, those specific to the lower gastrointestinal tract are less clear, as only a limited number of articles and case reports exist in the literature.

Case presentation
We describe a case of a 69-year-old woman who presented to the emergency department due to sudden onset abdominal distension and pain. Notably, she reported using intramuscular diclofenac sodium twice daily for 14 days after knee joint replacement surgery. The patient denied any other coexisting diseases. As a subsequent X-ray and computed tomography (CT) scan showed free air in the abdomen, an exploratory laparotomy was performed, revealing four free perforations in the terminal ileum. Findings on microscopic analysis were non-specific.

Conclusion
We report a unique case of multiple ileal perforations due to regular diclofenac sodium injections and contend that ileal perforation can be considered as a source for pneumoperitoneum with concomitant peritonitis in patients with a history of NSAID use if other possibilities are excluded.
A quantitative homogeneous assay for fragile X mental retardation 1 protein
Authors: Schutzius Gabi , Bleckmann Dorothee , Kapps-Fouthier Sandra , di Giorgio Francesco , Gerhartz Bernd , Weiss Andreas 
Published: April 2013

Abstract

Background
Hypermethylation of the fragile X mental retardation 1 gene FMR1 results in decreased expression of FMR1 protein FMRP, which is the underlying cause of Fragile X syndrome – an incurable neurological disorder characterized by mental retardation, anxiety, epileptic episodes and autism. Disease-modifying therapies for Fragile X syndrome are thus aimed at treatments that increase the FMRP expression levels in the brain. We describe the development and characterization of two assays for simple and quantitative detection of FMRP protein.

Method
Antibodies coupled to fluorophores that can be employed for time-resolved Förster’s resonance energy transfer were used for the development of homogeneous, one-step immunodetection. Purified recombinant human FMRP and patient cells were used as control samples for assay development.

Results
The assays require small sample amounts, display high stability and reproducibility and can be used to quantify endogenous FMRP in human fibroblasts and peripheral blood mononuclear cells. Application of the assays to FXS patient cells showed that the methods can be used both for the characterization of clinical FXS patient samples as well as primary readouts in drug-discovery screens aimed at increasing endogenous FMRP levels in human cells.

Conclusion
This study provides novel quantitative detection methods for FMRP in FXS patient cells. Importantly, due to the simplicity of the assay protocol, the method is suited to be used in screening applications to identify compounds or genetic interventions that result in increased FMRP levels in human cells.