293 research outputs found
Evaluating surgical skills from kinematic data using convolutional neural networks
The need for automatic surgical skills assessment is increasing, especially
because manual feedback from senior surgeons observing junior surgeons is prone
to subjectivity and time consuming. Thus, automating surgical skills evaluation
is a very important step towards improving surgical practice. In this paper, we
designed a Convolutional Neural Network (CNN) to evaluate surgeon skills by
extracting patterns in the surgeon motions performed in robotic surgery. The
proposed method is validated on the JIGSAWS dataset and achieved very
competitive results with 100% accuracy on the suturing and needle passing
tasks. While we leveraged from the CNNs efficiency, we also managed to mitigate
its black-box effect using class activation map. This feature allows our method
to automatically highlight which parts of the surgical task influenced the
skill prediction and can be used to explain the classification and to provide
personalized feedback to the trainee.Comment: Accepted at MICCAI 201
Anaplastic carcinoma of the pancreas producing granulocyte-colony stimulating factor: a case report
<p>Abstract</p> <p>Introduction</p> <p>The granulocyte-colony stimulating factor-producing tumor was first reported in 1977, however, anaplastic pleomorphic type carcinoma of the pancreas producing granulocyte-colony stimulating factor is still rare.</p> <p>Case presentation</p> <p>A 63-year-old man was admitted to our hospital with body weight loss (-10 kg during months) and upper abdominal pain from 3 weeks. Abdominal computed tomography demonstrated a pancreatic tumor 10 cm in size and multiple low-density areas in the liver. On admission, the peripheral leukocyte count was elevated to 91,500/mm<sup>3 </sup>and the serum concentration of granulocyte-colony stimulating factor was 134 pg/mL (normal, < 18.1 pg/mL). Based on liver biopsy findings, the tumor was classified as an anaplastic pleomorphic-type carcinoma. Immunohistochemical staining showed that pancreatic carcinoma cells were positive for granulocyte-colony stimulating factor. The patient developed interstitial pneumonia, probably caused by granulocyte-colony stimulating factor, and died 11 days after admission.</p> <p>Conclusion</p> <p>This is a rare case report of anaplastic pleomorphic-type carcinoma of the pancreas producing granulocyte-colony stimulating factor and confirmed by immunohistochemistry.</p
Diagnosis of ACL and meniscal injuries: MR imaging of knee flexion versus extension compared to arthroscopy
Clinical Significance of Serum Biomarkers in Pediatric Solid Mediastinal and Abdominal Tumors
Childhood cancer is the leading cause of death by disease among U.S. children between infancy and age 15. Despite successes in treating solid tumors such as Wilms tumor, disappointments in the outcomes of high-risk solid tumors like neuroblastoma have precipitated efforts towards the early and accurate detection of these malignancies. This review summarizes available solid tumor serum biomarkers with a special focus on mediastinal and abdominal cancers in children
Effect of organic tomato (Lycopersicon esculentum) extract on the genotoxicity of doxorubicin in the Drosophila wing spot test
The consumption of organic tomatoes (ORTs) reduces the risk of harmful effects to humans and the environment caused by exposure to toxic agrochemicals. In this study, we used the somatic mutation and recombination test (SMART) of wing spots in Drosophila melanogaster to evaluate the genotoxicity of ORT and the effect of cotreatment with ORT on the genotoxicity of Doxorubicin® (DXR, a cancer chemotherapeutic agent) that is mediated by free radical formation. Standard (ST) cross larvae were treated chronically with solutions containing 25%, 50% or 100% of an aqueous extract of ORT, in the absence and presence of DXR (0.125 mg/mL), and the number of mutant spots on the wings of emergent flies was counted. ORT alone was not genotoxic but enhanced the toxicity of DXR when administered concomitantly with DXR. The ORT-enhanced frequency of spots induced by DXR may have resulted from the interaction of ORT with the enzymatic systems that catalyze the metabolic detoxification of this drug
Breast tumour cell-induced down-regulation of type I collagen mRNA in fibroblasts
This study investigated the modulation of type I collagen gene expression in normal fibroblasts by breast tumour cells. Northern analysis of total RNA extracted from stages I, II and III breast tumour tissue revealed that collagen mRNA levels were elevated in stage I tumours compared to the adjacent normal breast tissues, whereas they were decreased in stages II and III breast tumours. This aberrant collagen gene expression was confirmed by non-radioactive RNA:RNA in situ hybridization analysis of 30 breast carcinomas which localized the production of type I collagen mRNA to the stromal fibroblasts within the vicinity of the tumour cells. In order to determine whether the tumour cells were directly responsible for this altered collagen production by the adjacent fibroblasts, breast tumour cell lines were co-cultured with normal fibroblasts for in vitro assessment of collagen and steady-state collagen RNA levels. Co-culture of tumour cells and normal fibroblasts in the same dish resulted in down-regulation of collagen mRNA and protein. Treatment of the fibroblasts with tumour-cell conditioned medium also resulted in decreased collagen protein levels but the mRNA levels, however, remained unaltered. These results suggested that the tumour cells either secrete a labile ‘factor’, or express a cell surface protein requiring direct contact with the fibroblasts, resulting in down-regulation of collagen gene expression. Modulation of the ECM is a common characteristic of invading tumour cells and usually involves increased production of collagenases by the tumour cells or stromal fibroblasts. This study showed that tumour cells were also able to modulate collagen mRNA production by stromal fibroblasts, which may facilitate tumour cell invasion and metastasis. © 1999 Cancer Research Campaig
A monodisperse transmembrane α-helical peptide barrel
The fabrication of monodisperse transmembrane barrels formed from short synthetic peptides has not been demonstrated previously. This is in part because of the complexity of the interactions between peptides and lipids within the hydrophobic environment of a membrane. Here we report the formation of a transmembrane pore through the self-assembly of 35 amino acid α-helical peptides. The design of the peptides is based on the C-terminal D4 domain of the Escherichia coli polysaccharide transporter Wza. By using single-channel current recording, we define discrete assembly intermediates and show that the pore is most probably a helix barrel that contains eight D4 peptides arranged in parallel. We also show that the peptide pore is functional and capable of conducting ions and binding blockers. Such α-helix barrels engineered from peptides could find applications in nanopore technologies such as single-molecule sensing and nucleic-acid sequencing
Immunophenotypic studies of monoclonal gammopathy of undetermined significance
<p>Abstract</p> <p>Background</p> <p>Monoclonal gammopathy of undetermined significance (MGUS) is a common plasma cell dyscrasia, comprising the most indolent form of monoclonal gammopathy. However, approximately 25% of MGUS cases ultimately progress to plasma cell myeloma (PCM) or related diseases. It is difficult to predict which subset of patients will transform. In this study, we examined the immunophenotypic differences of plasma cells in MGUS and PCM.</p> <p>Methods</p> <p>Bone marrow specimens from 32 MGUS patients and 32 PCM patients were analyzed by 4-color flow cytometry, using cluster analysis of ungated data, for the expression of several markers, including CD10, CD19, CD20, CD38, CD45, CD56 and surface and intracellular immunoglobulin light chains.</p> <p>Results</p> <p>All MGUS patients had two subpopulations of plasma cells, one with a "normal" phenotype [CD19(+), CD56(-), CD38(bright +)] and one with an aberrant phenotype [either CD19(-)/CD56(+) or CD19(-)/CD56(-)]. The normal subpopulation ranged from 4.4 to 86% (mean 27%) of total plasma cells. Only 20 of 32 PCM cases showed an identifiable normal subpopulation at significantly lower frequency [range 0–32%, mean 3.3%, p << 0.001]. The plasma cells in PCM were significantly less likely to express CD19 [1/32 (3.1%) vs. 13/29 (45%), p << 0.001] and more likely to express surface immunoglobulin [21/32 (66%) vs. 3/28 (11%), p << 0.001], compared to MGUS. Those expressing CD19 did so at a significantly lower level than in MGUS, with no overlap in mean fluorescence intensities [174 ± 25 vs. 430 ± 34, p << 0.001]. There were no significant differences in CD56 expression [23/32 (72%) vs. 18/29 (62%), p = 0.29], CD45 expression [15/32 (47%) vs. 20/30 (67%), p = 0.10] or CD38 mean fluorescence intensities [6552 ± 451 vs. 6365 ± 420, p = 0.38]. Two of the six MGUS cases (33%) with >90% CD19(-) plasma cells showed progression of disease, whereas none of the cases with >10% CD19(+) plasma cells evolved to PCM.</p> <p>Conclusion</p> <p>MGUS cases with potential for disease progression appeared to lack CD19 expression on >90% of their plasma cells, displaying an immunophenotypic profile similar to PCM plasma cells. A higher relative proportion of CD19(+) plasma cells in MGUS may be associated with a lower potential for disease progression.</p
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