97 research outputs found
Synaptophysin-Ki67 double stain: a novel technique that improves interobserver agreement in the grading of well-differentiated gastrointestinal neuroendocrine tumors.
A common problem in the assessment of Ki67 proliferative index in well-differentiated gastrointestinal neuroendocrine tumors is distinguishing tumor from non-tumor. This is because background stromal lymphocytes, entrapped non-neoplastic glands, and the delicate vascular network characteristic of neuroendocrine tumors frequently contain a subset of proliferating cells. Furthermore, in small biopsies, crush and cautery artifact can alter the morphologic appearance of tumor cells, making the Ki67 proliferative index more difficult to assess. To address these issues, we developed a synaptophysin-Ki67 double stain using a commercially available immunohistochemistry kit, allowing simultaneous visualization of tumor and proliferating nuclei. To test this method, three gastrointestinal pathologists individually graded 50 gastrointestinal neuroendocrine tumors first using synaptophysin-Ki67 double-stained slides and then, after a washout period, using Ki67-only stained slides (along with routine hematoxylin- and eosin-stained slides). Interobserver agreement on Ki67 proliferative index was moderate using the Ki67-only stained slides (intraclass correlation 0.51, 95% confidence interval: 0.35-0.66) and improved using the synaptophysin-Ki67 double stain (intraclass correlation 0.79, 95% confidence interval: 0.69-0.86). Similarly, interobserver agreement on tumor grade was fair with Ki67-only stained slides (Īŗ=0.39, P<0.001) and improved with the double stain (Īŗ=0.58, P<0.001). Analysis of individual pathologists' scores revealed that fewer total number of tumor cells counted correlated with higher grade designation and appeared to contribute to grade discordance. In tumors cited as particularly challenging to assess by the pathologists, three of four tumors were grade discordant with the Ki67-only stain, whereas all four tumors were grade concordant with the synaptophysin-Ki67 stain. The synaptophysin-Ki67 double stain is the first technique to address specifically the histomorphologic challenges of evaluating Ki67 proliferative index in well-differentiated gastrointestinal neuroendocrine tumors. Although further validation is needed, this study provides evidence that the synaptophysin-Ki67 double stain can improve interobserver agreement
One-stage partial vertebrectomy, titanium mesh implantation and pedicle screw fixation in the treatment of thoracolumbar burst fractures through a posterior approach
OBJECTIVE: To analyze the clinical results of a partial vertebrectomy with titanium mesh implantation and pedicle screw fixation using a posterior approach to reconstruct the spine in the treatment of thoracolumbar burst fractures. METHOD: From January 2006 to August 2008, 20 patients with severe thoracolumbar fractures were treated.For vertebral bodies associated with one injured intervertebral disk, subtotal vertebrectomy surgery and single-segment fusion were performed. For vertebral bodies with two injured adjacent intervertebral disks, partial vertebrectomy surgery and two-segment fusion were performed. RESULTS: All 20 patients were followed up for 12 to 24 months (average of 18 months). There were no complications such as wound infections, hemopneumothorax or abdominal infections in any of the patients. The neurological status of all of the patients was improved by at least one American Spinal Injury Association grade by the last follow-up. The anterior vertebral body height was an average of 50.77% before surgery, 88.51% after surgery and 87.86% at the last follow up; the sagittal Cobb angle was improved, on average, from 26.15Ā° to 5.39Ā° and was 5.90Ā° at the last follow up. The percentage of spinal stenosis was improved, on average, from 26.07% to 4.93%Ā° and was 6.15% at the last follow up. There were significant differences in the anterior vertebral body height pre- and post-surgery and in the sagittal Cobb angle and the percentage of spinal stenosis (
Codon optimization, constitutive expression and antimicrobial characterization of hen egg white lysozyme (HEWL) in Pichia pastoris
Fusarium oxysporum (F. oxysporum) and Verticillium dahlia (V. dahlia) causes severe cotton disease in China and other cotton-producing countries. Hen egg white lysozyme (HEWL) has antimicrobial properties. In this study, a codon-optimized HEWL gene was synthesized and cloned into the yeast expression vector, pPIC9K, under the control of the Pichia pastoris (P. pastoris) glyceraldehyde-3-phosphate dehydrogenase promoter (pGAP). Results showed that codon-optimized HEWL (oHEWL) was constitutively expressed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) indicated that the molecular weight of recombinant HEWL (roHEWL) was 14 kDa which corresponds to the standard HEWL. The expression of the roHEWL reached to 54 mg/L. Activity of the roHEWL was 1680 U/mL. The optimum pH for roHEWL was from 6.0 to 7.0, and the optimum temperature was 55Ā°C. In vitro antimicrobial activity assay revealed that roHEWL can lyse cell walls of the gram positive bacteria, Micrococcus lysodeikticus (M. lysodeikticus). In vivo studies showed that it inhibits plant fungi, F. oxysporum and V. dahlia. roHEWL anti-fungal properties might be useful for future genetically engineered cotton plant resistance against pathogenic fungal disease.Keywords: Hen egg white lysozyme (HEWL), antimicrobial activity, glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter, codon optimization, constitutive expressio
Geochemistry of soil gas in the seismic fault zone produced by the Wenchuan Ms 8.0 earthquake, southwestern China
The spatio-temporal variations of soil gas in the seismic fault zone produced by the 12 May 2008 Wenchuan Ms 8.0 earthquake were investigated based on the field measurements of soil gas concentrations after the main shock. Concentrations of He, H2, CO2, CH4, O2, N2, Rn, and Hg in soil gas were measured in the field at eight short profiles across the seismic rupture zone in June and December 2008 and July 2009. Soil-gas concentrations of more than 800 sampling sites were obtained. The data showed that the magnitudes of the He and H2 anomalies of three surveys declined significantly with decreasing strength of the aftershocks with time. The maximum concentrations of He and H2 (40 and 279.4 ppm, respectively) were found in three replicates at the south part of the rupture zone close to the epicenter. The spatio-temporal variations of CO2, Rn, and Hg concentrations differed obviously between the north and south parts of the fault zone. The maximum He and H2 concentrations in Jun 2008 occurred near the parts of the rupture zone where vertical displacements were larger. The anomalies of He, H2, CO2, Rn, and Hg concentrations could be related to the variation in the regional stress field and the aftershock activity
Role of femoral anterior Bow in cephalomedullary nailing: finite element analysis and New index estimation
Recombinase technology: applications and possibilities
The use of recombinases for genomic engineering is no longer a new technology. In fact, this technology has entered its third decade since the initial discovery that recombinases function in heterologous systems (Sauer in Mol Cell Biol 7(6):2087ā2096, 1987). The random insertion of a transgene into a plant genome by traditional methods generates unpredictable expression patterns. This feature of transgenesis makes screening for functional lines with predictable expression labor intensive and time consuming. Furthermore, an antibiotic resistance gene is often left in the final product and the potential escape of such resistance markers into the environment and their potential consumption raises consumer concern. The use of site-specific recombination technology in plant genome manipulation has been demonstrated to effectively resolve complex transgene insertions to single copy, remove unwanted DNA, and precisely insert DNA into known genomic target sites. Recombinases have also been demonstrated capable of site-specific recombination within non-nuclear targets, such as the plastid genome of tobacco. Here, we review multiple uses of site-specific recombination and their application toward plant genomic engineering. We also provide alternative strategies for the combined use of multiple site-specific recombinase systems for genome engineering to precisely insert transgenes into a pre-determined locus, and removal of unwanted selectable marker genes
One-stage partial vertebrectomy, titanium mesh implantation and pedicle screw fixation in the treatment of thoracolumbar burst fractures through a posterior approach
OBJECTIVE: To analyze the clinical results of a partial vertebrectomy with titanium mesh implantation and pedicle screw fixation using a posterior approach to reconstruct the spine in the treatment of thoracolumbar burst fractures. METHOD: From January 2006 to August 2008, 20 patients with severe thoracolumbar fractures were treated.For vertebral bodies associated with one injured intervertebral disk, subtotal vertebrectomy surgery and single-segment fusion were performed. For vertebral bodies with two injured adjacent intervertebral disks, partial vertebrectomy surgery and two-segment fusion were performed. RESULTS: All 20 patients were followed up for 12 to 24 months (average of 18 months). There were no complications such as wound infections, hemopneumothorax or abdominal infections in any of the patients. The neurological status of all of the patients was improved by at least one American Spinal Injury Association grade by the last follow-up. The anterior vertebral body height was an average of 50.77% before surgery, 88.51% after surgery and 87.86% at the last follow up; the sagittal Cobb angle was improved, on average, from 26.15Ā° to 5.39Ā° and was 5.90Ā° at the last follow up. The percentage of spinal stenosis was improved, on average, from 26.07% to 4.93%Ā° and was 6.15% at the last follow up. There were significant differences in the anterior vertebral body height pre- and post-surgery and in the sagittal Cobb angle and the percentage of spinal stenosis (p<0) in all patients. CONCLUSIONS: This surgical procedure is simple and can accomplish decompression, reduction, fixation and fusion of the spine in one stage. This approach could be widely used in orthopedics
Contrastive Analysis and Accuracy Assessment of Three Global 30 m Land Cover Maps Circa 2020 in Arid Land
Fine-resolution land cover (LC) products are critical for studies of urban planning, global climate change, the Earth’s energy balance, and the geochemical cycle as fundamental geospatial data products. It is important and urgent to evaluate the performance of the updated global land cover maps. In this study, three widely used LC maps with 30 m spatial resolution (FROM-GLC30-2020, GLC_FCS30, and GlobeLand30) published around 2020 were evaluated in terms of their degree of consistency and accuracy metrics. First, we compared their similarities and difference in the area ratio and spatial patterns over different land cover types. Second, the sample and response protocol was proposed and validation samples were collected. Based on this, the overall accuracy, producer’s accuracy, and user’s accuracy were analyzed. The results revealed that: (1) the consistent areas of the three maps accounted for 65.96% of the total area and that two maps exceeded 75% of it. (2) The dominant land cover types, bare land and grassland, were the most consistent land cover types across the three products. In contrast, the spatial inconsistency of the wetland, shrubland, and built-up areas were relatively high, with the disagreement mainly occurring in the heterogeneous regions. (3) The overall accuracy of the GLC_FCS30 map was the highest with a value of 87.07%, which was followed by GlobeLand30 (85.69%) and FROM-GLC30 (83.49%). Overall, all three of the LC maps were found to be consistent and have a good performance in classification in the arid regions, but their ability to accurately classify specific types varied
Evaluating a Medical School's Climate for Women's Success: Outcomes for Faculty Recruitment, Retention, and Promotion
ObjectiveWomen are under-represented in academia. Causative factors include challenges of career-family integration. We evaluated factors reflecting institutional culture (promotion, retention, hiring, and biasing language in promotion letters) as part of an intervention to help shift culture and raise awareness of flexibility policies at the University of California, Davis (UCD).Materials and methodsData on faculty use of family-friendly policies were obtained at baseline, and surveys for policy awareness were conducted pre(2010)/post(2013) an NIH-funded study educational intervention. Data on hires, separations, and promotions were obtained pre(2007-2009, 2234 person-year data points)/post(2010-2012, 2384 person-year data points) intervention and compared by logistic regression and for gender differences. Department promotion letters (53) were also analyzed for biasing language.ResultsPolicy use was overall low, highest for female assistant professors, and for maternity leave. Awareness significantly increased for all policies postintervention. Promotions decreased, likely because of increases in advancement deferrals or tenure clock extensions. Pre/postintervention, female and male hires were near parity for assistant professors, but female hires were substantially lower than males for associate (54% less likely, pā=ā0.03) and full professors (70% less likely, pā=ā0.002). Once hired, women were no more likely to separate than men. Fewer associate/full professors separated than assistant professors (pā=ā0.002, pā<ā0.001, respectively), regardless of gender. Language in promotion letters was not gender biased.ConclusionsWe demonstrate a shift at UCD toward a culture of work-life flexibility, an environment in which letters of recommendation show very few biased descriptions, and in which assistant professor hiring is gender equitable. At the same time, a decrease in number of faculty members applying for promotion and an imbalance of men over women at senior hires independent of policy awareness may challenge the assumption that family-friendly policies, while promoting flexibility, also have a positive impact on professional advancement
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