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AIM: To determine (a) the accuracy of ultrasound in detecting brachial plexus pathology and (b) outline the advantages and limitations of ultrasound compared to MRI for imaging the brachial plexus. MATERIAL AND METHODS: cases with clinically suspected brachial plexus pathology were evaluated first by ultrasound, followed by MRI. Patients with prior brachial plexus imaging were excluded. The final diagnosis was based on a combination of ultrasound, MRI, clinical follow-up, and surgical findings. The accuracy of the ultrasound was assessed by comparing the ultrasound and the final diagnoses. The mean clinical follow-up time following ultrasound was 1.8 ± 1.4 years. RESULTS: Ninety-two (64%) of the 143 cases had normal brachial plexus ultrasound and MRI examinations. Fifty-one (36%) of 143 cases had brachial plexus pathology on MRI, comprising post-radiation fibrosis (n=25, 49%), nerve sheath tumor (n=11, 21%), traumatic injury (n=7, 14%), inflammatory polyneuropathy (n=4, 8%), malignant infiltration (n=2, 4%), desmoid fibromatosis (n=1,2%), and neuralgic amyotrophy (n=1, 2%). Overall diagnostic accuracy of ultrasound for brachial plexus pathology was 98% (140/143), with three discordant cases (neuralgic amyotrophy n=1, inflammatory neuropathy n=1, postradiation fibrosis n=1) regarded as normal on ultrasound assessment. Sensitivity, specificity, and positive and negative predictive value of ultrasound for identifying brachial plexus pathology were 94%, 100%, 100%, and 97%, respectively. CONCLUSION: Ultrasound identifies brachial plexus pathology with high accuracy and specificity, showing comparable diagnostic efficacy to MRI. Ultrasound can serve as an effective first-line imaging investigation for suspected brachial plexus pathology.
Subject(s)
Brachial Plexus , Magnetic Resonance Imaging , Ultrasonography , Humans , Female , Male , Brachial Plexus/diagnostic imaging , Brachial Plexus/pathology , Adult , Middle Aged , Magnetic Resonance Imaging/methods , Ultrasonography/methods , Aged , Sensitivity and Specificity , Adolescent , Brachial Plexus Neuropathies/diagnostic imaging , Young Adult , Reproducibility of Results , Child , Aged, 80 and overABSTRACT
BACKGROUND: Recent advances are enabling delivery of precision genomic medicine to cancer clinics. While the majority of approaches profile panels of selected genes or hotspot regions, comprehensive data provided by whole-genome and transcriptome sequencing and analysis (WGTA) present an opportunity to align a much larger proportion of patients to therapies. PATIENTS AND METHODS: Samples from 570 patients with advanced or metastatic cancer of diverse types enrolled in the Personalized OncoGenomics (POG) program underwent WGTA. DNA-based data, including mutations, copy number and mutation signatures, were combined with RNA-based data, including gene expression and fusions, to generate comprehensive WGTA profiles. A multidisciplinary molecular tumour board used WGTA profiles to identify and prioritize clinically actionable alterations and inform therapy. Patient responses to WGTA-informed therapies were collected. RESULTS: Clinically actionable targets were identified for 83% of patients, of which 37% of patients received WGTA-informed treatments. RNA expression data were particularly informative, contributing to 67% of WGTA-informed treatments; 25% of treatments were informed by RNA expression alone. Of a total 248 WGTA-informed treatments, 46% resulted in clinical benefit. RNA expression data were comparable to DNA-based mutation and copy number data in aligning to clinically beneficial treatments. Genome signatures also guided therapeutics including platinum, poly-ADP ribose polymerase inhibitors and immunotherapies. Patients accessed WGTA-informed treatments through clinical trials (19%), off-label use (35%) and as standard therapies (46%) including those which would not otherwise have been the next choice of therapy, demonstrating the utility of genomic information to direct use of chemotherapies as well as targeted therapies. CONCLUSIONS: Integrating RNA expression and genome data illuminated treatment options that resulted in 46% of treated patients experiencing positive clinical benefit, supporting the use of comprehensive WGTA profiling in clinical cancer care.
Subject(s)
Neoplasms , Gene Expression Profiling , Genomics/methods , Humans , Mutation , Neoplasms/drug therapy , Neoplasms/genetics , Precision Medicine/methods , RNA , TranscriptomeABSTRACT
AIM: To compare technical success, diagnostic accuracy, and histological yield of fine-needle aspiration cytology (FNAC), side-cutting (Temno) needle biopsy, and end-cutting (Franseen) needle biopsy for ultrasound-guided sampling of groin and axillary lymph nodes. MATERIALS AND METHODS: A total of 270 abnormal groin and axillary nodes were sampled using one of the three techniques. Nodes with a maximum length of <2.5 cm underwent FNAC or Franseen biopsy, while nodes >2.5 cm underwent Temno biopsy. Mean size of nodes sampled by FNAC (21.2 mm) and Franseen (19.7 mm) were similar while nodes sampled by Temno were larger (34.4 mm, p<0.0001). RESULTS: Technical success rates of FNAC (82/93, 88%), Franseen (105/111, 95%), and Temno (59/66, 89%) biopsies were similar (p>0.05 for all). Lymphoid tissue yield by FNAC (mean total area 1.51 mm2) was less than that by Franseen (7.14 mm2, p=0.002) or Temno biopsy (19.44 mm2, p<0.0001). Diagnostic accuracy for malignancy was lower for FNAC (22/30, 73%) than Franseen (25/26, 96%, p=0.02) or Temno biopsy (32/32, 100%, p=0.002). For malignant nodes, determining the likely organ of origin was also lower for FNAC (7/30, 23%) than Franseen (19/26, 73%, p=0.0002) or Temno biopsy (29/32, 91%, p<0.0001), with a similar pattern observed in the identification of lymphoma. CONCLUSION: For similarly sized nodes, Franseen biopsy provided more lymphoid material, a higher diagnostic accuracy for malignancy including lymphoma, and better identification of the likely organ of origin than FNAC. Routine use of Franseen biopsy is advocated rather than FNAC for percutaneous sampling of lymph nodes not suitable for side-cutting needle biopsy.
Subject(s)
Breast Neoplasms , Lymph Nodes , Axilla/diagnostic imaging , Biopsy, Fine-Needle , Breast Neoplasms/pathology , Female , Humans , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Lymphatic Metastasis/pathology , Ultrasonography, Interventional/methodsABSTRACT
BACKGROUND AND PURPOSE: Collateral blood supply is a key determinant of outcome in large-vessel occlusion acute ischemic stroke. Single- and multiphase CTA collateral scoring systems have been described but are subjective and require training. We aimed to test whether the CTP-derived hypoperfusion intensity ratio is associated with CTA collateral status and whether a threshold hypoperfusion intensity ratio exists that predicts poor CTA collaterals. MATERIALS AND METHODS: Imaging and clinical data of consecutive patients with large-vessel occlusion acute ischemic stroke were retrospectively reviewed. Single-phase CTA and multiphase CTA scoring were performed by 2 blinded neuroradiologists using the Tan, Maas, and Calgary/Menon methods. CTP was processed using RApid processing of PerfusIon and Diffusion software (RAPID). Hypoperfusion intensity ratio = ratio of brain volume with time-to-maximum >10 seconds over time-to-maximum >6-second volume. Correlation between the hypoperfusion intensity ratio and CTA collateral scores was calculated using the Pearson correlation. The optimal threshold of the hypoperfusion intensity ratio for predicting poor collaterals was determined using receiver operating characteristic curve analysis. RESULTS: Fifty-two patients with large-vessel occlusion acute ischemic stroke were included. Multiphase CTA collateral scoring showed better interrater agreement (κ = 0.813) than single-phase CTA (Tan, κ = 0.587; Maas, κ = 0.273). The hypoperfusion intensity ratio correlated with CTA collateral scores (multiphase CTA: r = -0.55; 95% CI, -0.67 to -0.40; P ≤ .001). The optimal threshold for predicting poor multiphase CTA collateral status was a hypoperfusion intensity ratio of >0.45 (sensitivity = 78%; specificity = 76%; area under the curve = 0.86). Patients with high hypoperfusion intensity ratio/poor collateral status had lower ASPECTS/larger infarcts, higher NIHSS scores, and larger hypoperfused volumes. CONCLUSIONS: The hypoperfusion intensity ratio is associated with CTA collateral status in patients with large-vessel occlusion acute ischemic stroke. The hypoperfusion intensity ratio is an automated and quantitative alternative to CTA collateral scoring methods for both clinical and future stroke trial settings.
Subject(s)
Brain Ischemia , Ischemic Stroke , Stroke , Brain Ischemia/diagnostic imaging , Cerebral Angiography , Collateral Circulation , Computed Tomography Angiography , Humans , Retrospective Studies , Stroke/diagnostic imagingABSTRACT
Background: Single-gene tests and hotspot panels targeting specific subsets of biomarkers constitute the Canadian genomic testing landscape for non-small-cell lung cancer (nsclc). However, newer testing options such as comprehensive genomic profiling (cgp) offer improved detection rates and identification of multiple classes of genomic alterations in a single assay, minimizing tissue requirements and turnaround time. The objective of the present analysis was to assess the health and budget impacts of adopting cgp testing for nsclc in Canada. Methods: This study assessed the impact of funding the cgp tests FoundationOne CDx and FoundationOne Liquid (Foundation Medicine, Cambridge, MA, U.S.A.) over a 3-year time horizon using a Canadian societal perspective for Ontario. Conventional testing strategies were summarized into two reference scenarios: a series of single-gene tests only, and reflex single-gene testing followed by a hotspot panel for negative results. Four adoption scenarios for cgp testing were considered: replacing all single-gene and hotspot panel testing, replacing hotspot panel testing only, use after negative single-gene and hotspot testing, and use of FoundationOne Liquid in individuals with insufficient tissue for conventional testing. Results: When cgp testing was assumed to replace all conventional testing with 50% uptake, the budget impact per person per year ranged from $0.71 to $0.87, depending on the reference scenario, with a 3-year gain of 680.9 life-years and 3831 working days over the full cohort. Conclusions: Given the present testing landscape for patients with nsclc in Canada, listing cgp testing could optimize the selection of appropriately targeted treatments, and thus add life-years and productivity for this population, with a minimal budget impact.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/genetics , Genetic Testing , Genomics , Humans , Lung Neoplasms/genetics , OntarioABSTRACT
Rapid advancements in next-generation sequencing (ngs) technology have created an unprecedented opportunity to decipher the molecular profile of tumours to more effectively prevent, diagnose, and treat cancer. Oncologists now have the option to order molecular tests that can guide treatment decisions. However, to date, most oncologists have received limited training in genomics, and they are now faced with the challenge of understanding how such tests and their interpretation align with patient management. Guidance on how to effectively use ngs technology is therefore needed to aid oncologists in applying the results of genomic tests. The Canadian guideline presented here describes best practices and unmet needs related to ngs-based testing for somatic variants in oncology, including clinical application, assay and sample selection, bioinformatics and interpretation of reports performed by laboratories, patient communication, and clinical trials.
Subject(s)
High-Throughput Nucleotide Sequencing , Medical Oncology/methods , Neoplasms/genetics , Practice Guidelines as Topic , Canada , Communication , Computational Biology , Humans , Immunotherapy , Molecular Targeted Therapy , Neoplasms/diagnosis , Neoplasms/therapy , Patient Education as Topic , WorkflowABSTRACT
We demonstrate coupling between the atomic spin- and orbital-angular momentum (OAM) of the atom's center-of-mass motion in a Bose-Einstein condensate (BEC). The coupling is induced by Raman-dressing lasers with a Laguerre-Gaussian beam and creates coreless vortices in an F=1 ^{87}Rb spinor BEC. We observe correlations between spin and OAM in the dressed state and characterize the spin texture; the result is in good agreement with the theory. In the presence of the Raman field, our dressed state is stable for 0.1 s or longer, and it decays due to collision-induced relaxation. As we turn off the Raman beams, the vortex cores in the bare spin |m_{F}=1⟩ and |-1⟩ split. These spin-OAM coupled systems with the Raman-dressing approach have great potential for exploring new topological textures and quantum states.
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BACKGROUND: Previous attempts to improve the quality of health journalism have not led to more responsible reporting of health news. METHOD: We reviewed the front pages of three daily tabloid and three daily broadsheet UK newspapers during a 1 month period in 2017 for medical headlines in which claims were made for diets, lifestyle behaviours or drug therapies that influence health. RESULTS: Front page medical headlines were carried by the Daily Express (11), Daily Mail (two), Daily Mirror (one) and Daily Telegraph (one). Neither the Guardian nor the Independent carried medical stories on their front pages during the period of study. Eleven headlines suggested benefits and three suggested harm. One headline accurately reflected its source material, but in this instance the source material was of doubtful clinical relevance. The remaining 13 headlines either exaggerated benefit (seven), exaggerated harm (two) or made false claims (four). CONCLUSIONS: The cumulative effect of everyday misreporting of medical stories in UK newspapers may not only serve to confuse the public but also have serious consequences for public health.
Subject(s)
Consumer Health Information/standards , Journalism, Medical/standards , Newspapers as Topic/standards , Biomedical Research , Communication , Humans , Public Health , United KingdomABSTRACT
Lymph nodal disease (LN+) is the most significant prognostic factor of oral squamous cell carcinoma (OSCC). Current risk indicator(s) for guiding elective neck dissection (END) is insufficient for clinically node-negative (cN0) patients, resulting in under- or overtreatment. While the role of immunological events in tumorigenesis and metastasis is evident, the prognostic implication in OSCC remains unclear. The study objective was to investigate large-scale immune-related gene expression and determine its prognostic value on node-free survival (NFS). We analyzed patients who received intent-to-cure surgery with at least 3 y of follow-up and known outcome of LN through a pan-Canadian surgical trial. Total RNA was extracted from surgical tissues with >70% tumor content and analyzed on a 730-gene panel (NanoString nCounter® PanCancer Immune Panel). We first profiled gene expression in a fresh-frozen (FF) discovery set to identify differentially expressed (DE) genes, which were then used in unsupervised clustering analysis to identify patient subgroups. The prognostic value of the identified DE genes was then validated on formalin-fixed, paraffin-embedded (FFPE) samples. A total of 177 RNA samples were derived from 89 FF and 88 FFPE surgical tissues, of which 45 (51%) and 40 (45%), respectively, were from patients who developed LN+. We identified 6 DE genes overexpressed in LN+ tumors (false discovery rate <0.001; log2 fold change >1). Clustering analysis separated the patients into 2 subgroups (CM1, CM2), with CM2 exhibiting significantly increased expression and worse 5-y NFS rate (28%; P < 0.001). The prognostic value of these 6 candidate genes was validated on FFPE samples, which were also separated into 2 distinct prognostic groups, confirming the association between increased gene expression and poor 5-y NFS (CM1, 70.3%; CM2, 43.3%; P = 0.01). This is the first study identifying a panel of immune-related genes associated with NFS that can potentially be used clinically stratifying the risk of LN+ at the time of OSCC diagnosis.
Subject(s)
Carcinoma, Squamous Cell/diagnosis , Mouth Neoplasms/diagnosis , Adult , Aged , Carcinoma, Squamous Cell/metabolism , Carcinoma, Squamous Cell/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , Lymphatic Metastasis/diagnosis , Male , Middle Aged , Mouth Neoplasms/metabolism , Mouth Neoplasms/pathology , Prognosis , Proportional Hazards Models , TranscriptomeABSTRACT
We demonstrate synthetic azimuthal gauge potentials for Bose-Einstein condensates from engineering atom-light couplings. The gauge potential is created by adiabatically loading the condensate into the lowest energy Raman-dressed state, achieving a coreless vortex state. The azimuthal gauge potentials act as effective rotations and are tunable by the Raman coupling and detuning. We characterize the spin textures of the dressed states, in agreements with the theory. The lowest energy dressed state is stable with a 4.5-s half-atom-number-fraction lifetime. In addition, we exploit the azimuthal gauge potential to demonstrate the Hess-Fairbank effect, the analogue of Meissner effect in superconductors. The atoms in the absolute ground state has a zero quasiangular momentum and transits into a polar-core vortex when the synthetic magnetic flux is tuned to exceed a critical value. Our demonstration serves as a paradigm to create topological excitations by tailoring atom-light interactions where both types of SO(3) vortices in the |⟨F[over â]⟩|=1 manifold, coreless vortices and polar-core vortices, are created in our experiment. The gauge field in the stationary Hamiltonian opens a path to investigating rotation properties of atomic superfluids under thermal equilibrium.
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BACKGROUND: NRG1 fusion-positive lung cancers have emerged as potentially actionable events in lung cancer, but clinical support is currently limited and no evidence of efficacy of this approach in cancers beyond lung has been shown. PATIENTS AND METHODS: Here, we describe two patients with advanced cancers refractory to standard therapies. Patient 1 had lung adenocarcinoma and patient 2 cholangiocarcinoma. Whole-genome and transcriptome sequencing were carried out for these cases with select findings validated by fluorescence in situ hybridization. RESULTS: Both tumors were found to be positive for NRG1 gene fusions. In patient 1, an SDC4-NRG1 gene fusion was detected, similar gene fusions having been described in lung cancers previously. In patient 2, a novel ATP1B1-NRG1 gene fusion was detected. Cholangiocarcinoma is not a disease type in which NRG1 fusions had been described previously. Integrative genome analysis was used to assess the potential functional significance of the detected genomic events including the gene fusions, prioritizing therapeutic strategies targeting the HER-family of growth factor receptors. Both patients were treated with the pan HER-family kinase inhibitor afatinib and both displayed significant and durable response to treatment. Upon progression sites of disease were sequenced. The lack of obvious genomic events to describe the disease progression indicated that broad transcriptomic or epigenetic mechanisms could be attributed to the lack of prolonged response to afatinib. CONCLUSION: These observations lend further support to the use of pan HER-tyrosine kinase inhibitors for the treatment of NRG1 fusion-positive in both cancers of lung and hepatocellular origin and indicate more broadly that cancers found to be NRG1 fusion-positive may benefit from such a clinical approach regardless of their site of origin. CLINICAL TRIAL INFORMATION: Personalized Oncogenomics (POG) Program of British Columbia: Utilization of Genomic Analysis to Better Understand Tumour Heterogeneity and Evolution (NCT02155621).
Subject(s)
Adenocarcinoma/drug therapy , Bile Duct Neoplasms/drug therapy , Cholangiocarcinoma/drug therapy , Lung Neoplasms/drug therapy , Neuregulin-1/genetics , Neuregulin-1/metabolism , Quinazolines/therapeutic use , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Adenocarcinoma of Lung , Adult , Afatinib , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/metabolism , Cholangiocarcinoma/genetics , Cholangiocarcinoma/metabolism , Female , Gene Expression Profiling , Humans , In Situ Hybridization, Fluorescence , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Oncogene Proteins, Fusion/genetics , Oncogene Proteins, Fusion/metabolism , Protein Kinase Inhibitors/therapeutic use , Syndecan-4/geneticsABSTRACT
INTRODUCTION: There are two antivenoms that may be administered in Hong Kong following a bite by Trimeresurus albolabris: the green pit viper antivenom from the Thai Red Cross Society in Thailand and the Agkistrodon halys antivenom from the Shanghai Institute of Biological Products in China. Both are recommended by the Central Coordinating Committee of Accident and Emergency Services of the Hospital Authority for treating patients with a bite by Trimeresurus albolabris. The choice of which antivenom to use is based on physician preference. This study aimed to compare the relative efficacy of the two antivenoms. METHODS: This in-vitro experimental study was carried out by a wildlife conservation organisation and a regional hospital in Hong Kong. Human plasma from 40 adult health care worker volunteers was collected. The Trimeresurus albolabris venom was added to human plasma and the mixture was assayed after incubation with each antivenom (green pit viper and Agkistrodon halys) using saline as a control. Fibrinogen level and clotting time in both antivenom groups were studied. RESULTS: The mean fibrinogen level was elevated from 0 g/L to 2.86 g/L and 1.11 g/L after the addition of green pit viper antivenom and Agkistrodon halys antivenom, respectively. When mean clotting time was measured, the value was 6.70 minutes in the control, prolonged to more than 360 minutes by green pit viper antivenom and to 19.06 minutes by Agkistrodon halys antivenom. CONCLUSIONS: Green pit viper antivenom was superior to Agkistrodon halys antivenom in neutralisation of the thrombin-like and hypofibrinogenaemic activities of Trimeresurus albolabris venom.
Subject(s)
Antivenins/pharmacology , Blood Coagulation/drug effects , Crotalid Venoms/antagonists & inhibitors , Adult , Blood Coagulation Tests , China , Crotalid Venoms/poisoning , Healthy Volunteers , Hong Kong , Humans , Snake Bites/therapy , Thailand , Time FactorsABSTRACT
Clinical outcome and mutations of 96 core-binding factor acute myeloid leukemia (AML) patients 18-60 years old were examined. Complete remission (CR) after induction was 94.6%. There was no significant difference in CR, leukemia-free-survival (LFS) and overall survival (OS) between t(8;21) (N=67) and inv(16) patients (N=29). Univariate analysis showed hematopoietic stem cell transplantation at CR1 as the only clinical parameter associated with superior LFS. Next-generation sequencing based on a myeloid gene panel was performed in 72 patients. Mutations in genes involved in cell signaling were associated with inferior LFS and OS, whereas those in genes involved in DNA methylation were associated with inferior LFS. KIT activation loop (AL) mutations occurred in 25 patients, and were associated with inferior LFS (P=0.003) and OS (P=0.001). TET2 mutations occurred in 8 patients, and were associated with significantly shorter LFS (P=0.015) but not OS. Patients negative for KIT-AL and TET2 mutations (N=41) had significantly better LFS (P<0.001) and OS (P=0.012) than those positive for both or either mutation. Multivariate analysis showed that KIT-AL and TET2 mutations were associated with inferior LFS, whereas age ⩾40 years and marrow blast ⩾70% were associated with inferior OS. These observations provide new insights that may guide better treatment for this AML subtype.
Subject(s)
Core Binding Factors/genetics , Core Binding Factors/metabolism , DNA-Binding Proteins/genetics , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Mutation , Proto-Oncogene Proteins c-kit/metabolism , Proto-Oncogene Proteins/genetics , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Combined Modality Therapy , DNA Methylation , DNA Mutational Analysis , DNA-Binding Proteins/metabolism , Dioxygenases , Female , Hematopoietic Stem Cell Transplantation/methods , High-Throughput Nucleotide Sequencing , Humans , Leukemia, Myeloid, Acute/mortality , Leukemia, Myeloid, Acute/therapy , Male , Middle Aged , Prognosis , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-kit/genetics , Signal Transduction , Survival Analysis , Translocation, Genetic , Transplantation, Homologous , Young AdultABSTRACT
BACKGROUND: A patient suffering from metastatic colorectal cancer, treatment-related toxicity and resistance to standard chemotherapy and radiation was assessed as part of a personalized oncogenomics initiative to derive potential alternative therapeutic strategies. PATIENTS AND METHODS: Whole-genome and transcriptome sequencing was used to interrogate a metastatic tumor refractory to standard treatments of a patient with mismatch repair-deficient metastatic colorectal cancer. RESULTS: Integrative genomic analysis indicated overexpression of the AP-1 transcriptional complex suggesting experimental therapeutic rationales, including blockade of the renin-angiotensin system. This led to the repurposing of the angiotensin II receptor antagonist, irbesartan, as an anticancer therapy, resulting in the patient experiencing a dramatic and durable response. CONCLUSIONS: This case highlights the utility of comprehensive integrative genomic profiling and bioinformatics analysis to provide hypothetical rationales for personalized treatment options.
Subject(s)
Biphenyl Compounds/administration & dosage , Colorectal Neoplasms/drug therapy , Precision Medicine , Tetrazoles/administration & dosage , Transcription Factor AP-1/genetics , Aged , Angiotensin Receptor Antagonists/administration & dosage , Angiotensins/antagonists & inhibitors , Angiotensins/genetics , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Computational Biology , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Irbesartan , Neoplasm Metastasis , Renin-Angiotensin System/drug effects , Transcriptome/geneticsABSTRACT
We study the magnetoelectric coupling at the surface of a topological insulator. We are particularly interested in the surface current induced by a static Zeeman/exchange field. This surface current can be related to the orbital magnetization of the system. For an insulator with zero Chern number, the orbital magnetization is independent of the details at the boundary. With the appearance of surface states in the topological insulator, it is not immediately obvious if the response is affected by the conditions at the surface. We investigate this question using exact diagonalization to a lattice model. By applying a time-reversal symmetry-breaking term near the boundary, even if the surface states are gapped out, we still find no change in the surface current. This arises from cancelations between Pauli and Van Vleck contributions between surface and bulk scattering states. We also show that the surface current response is independent of the chemical potential when it is within the bulk gap. Our results are consistent with the claim that orbital magnetization is a bulk property.
ABSTRACT
BACKGROUND: Gastrointestinal carcinomas are genomically complex cancers that are lethal in the metastatic setting. Whole-genome and transcriptome sequencing allow for the simultaneous characterization of multiple oncogenic pathways. METHODS: We report 3 cases of metastatic gastrointestinal carcinoma in patients enrolled in the Personalized Onco-Genomics program at the BC Cancer Agency. Real-time genomic profiling was combined with clinical expertise to diagnose a carcinoma of unknown primary, to explore treatment response to bevacizumab in a colorectal cancer, and to characterize an appendiceal adenocarcinoma. RESULTS: In the first case, genomic profiling revealed an IDH1 somatic mutation, supporting the diagnosis of cholangiocarcinoma in a malignancy of unknown origin, and further guided therapy by identifying epidermal growth factor receptor amplification. In the second case, a BRAF V600E mutation and wild-type KRAS profile justified the use of targeted therapies to treat a colonic adenocarcinoma. The third case was an appendiceal adenocarcinoma defined by a p53 inactivation; Ras/raf/mek, Akt/mtor, Wnt, and notch pathway activation; and overexpression of ret, erbb2 (her2), erbb3, met, and cell cycle regulators. SUMMARY: We show that whole-genome and transcriptome sequencing can be achieved within clinically effective timelines, yielding clinically useful and actionable information.