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1.
Proc Natl Acad Sci U S A ; 121(13): e2320053121, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38513100

ABSTRACT

Lysosome-targeting chimeras (LYTACs) are a promising therapeutic modality to drive the degradation of extracellular proteins. However, early versions of LYTAC contain synthetic glycopeptides that cannot be genetically encoded. Here, we present our designs for a fully genetically encodable LYTAC (GELYTAC), making our tool compatible with integration into therapeutic cells for targeted delivery at diseased sites. To achieve this, we replaced the glycopeptide portion of LYTACs with the protein insulin-like growth factor 2 (IGF2). After showing initial efficacy with wild-type IGF2, we increased the potency of GELYTAC using directed evolution. Subsequently, we demonstrated that our engineered GELYTAC construct not only secretes from HEK293T cells but also from human primary T-cells to drive the uptake of various targets into receiver cells. Immune cells engineered to secrete GELYTAC thus represent a promising avenue for spatially selective targeted protein degradation.


Subject(s)
Lysosomes , Humans , HEK293 Cells , Proteolysis
2.
Nature ; 583(7817): 548-553, 2020 07.
Article in English | MEDLINE | ID: mdl-32480398

ABSTRACT

Tertiary stereogenic centres containing one fluorine atom are valuable for medicinal chemistry because they mimic common tertiary stereogenic centres containing one hydrogen atom, but they possess distinct charge distribution, lipophilicity, conformation and metabolic stability1-3. Although tertiary stereogenic centres containing one hydrogen atom are often set by enantioselective desymmetrization reactions at one of the two carbon-hydrogen (C-H) bonds of a methylene group, tertiary stereocentres containing fluorine have not yet been constructed by the analogous desymmetrization reaction at one of the two carbon-fluorine (C-F) bonds of a difluoromethylene group3. Fluorine atoms are similar in size to hydrogen atoms but have distinct electronic properties, causing C-F bonds to be exceptionally strong and geminal C-F bonds to strengthen one another4. Thus, exhaustive defluorination typically dominates over the selective replacement of a single C-F bond, hindering the development of the enantioselective substitution of one fluorine atom to form a stereogenic centre5,6. Here we report the catalytic, enantioselective activation of a single C-F bond in an allylic difluoromethylene group to provide a broad range of products containing a monofluorinated tertiary stereogenic centre. By combining a tailored chiral iridium phosphoramidite catalyst, which controls regioselectivity, chemoselectivity and enantioselectivity, with a fluorophilic activator, which assists the oxidative addition of the C-F bond, these reactions occur in high yield and selectivity. The design principles proposed in this work extend to palladium-catalysed benzylic substitution, demonstrating the generality of the approach.


Subject(s)
Carbon/chemistry , Fluorine/chemistry , Alkenes/chemistry , Catalysis , Cations , Halogenation , Hydrogen/chemistry , Iridium/chemistry , Organophosphorus Compounds/chemistry , Oxidation-Reduction , Palladium/chemistry
3.
Lancet ; 403(10422): 171-182, 2024 Jan 13.
Article in English | MEDLINE | ID: mdl-38104577

ABSTRACT

BACKGROUND: Most patients with metastatic cancer eventually develop resistance to systemic therapy, with some having limited disease progression (ie, oligoprogression). We aimed to assess whether stereotactic body radiotherapy (SBRT) targeting oligoprogressive sites could improve patient outcomes. METHODS: We did a phase 2, open-label, randomised controlled trial of SBRT in patients with oligoprogressive metastatic breast cancer or non-small-cell lung cancer (NSCLC) after having received at least first-line systemic therapy, with oligoprogression defined as five or less progressive lesions on PET-CT or CT. Patients aged 18 years or older were enrolled from a tertiary cancer centre in New York, NY, USA, and six affiliated regional centres in the states of New York and New Jersey, with a 1:1 randomisation between standard of care (standard-of-care group) and SBRT plus standard of care (SBRT group). Randomisation was done with a computer-based algorithm with stratification by number of progressive sites of metastasis, receptor or driver genetic alteration status, primary site, and type of systemic therapy previously received. Patients and investigators were not masked to treatment allocation. The primary endpoint was progression-free survival, measured up to 12 months. We did a prespecified subgroup analysis of the primary endpoint by disease site. All analyses were done in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT03808662, and is complete. FINDINGS: From Jan 1, 2019, to July 31, 2021, 106 patients were randomly assigned to standard of care (n=51; 23 patients with breast cancer and 28 patients with NSCLC) or SBRT plus standard of care (n=55; 24 patients with breast cancer and 31 patients with NSCLC). 16 (34%) of 47 patients with breast cancer had triple-negative disease, and 51 (86%) of 59 patients with NSCLC had no actionable driver mutation. The study was closed to accrual before reaching the targeted sample size, after the primary efficacy endpoint was met during a preplanned interim analysis. The median follow-up was 11·6 months for patients in the standard-of-care group and 12·1 months for patients in the SBRT group. The median progression-free survival was 3·2 months (95% CI 2·0-4·5) for patients in the standard-of-care group versus 7·2 months (4·5-10·0) for patients in the SBRT group (hazard ratio [HR] 0·53, 95% CI 0·35-0·81; p=0·0035). The median progression-free survival was higher for patients with NSCLC in the SBRT group than for those with NSCLC in the standard-of-care group (10·0 months [7·2-not reached] vs 2·2 months [95% CI 2·0-4·5]; HR 0·41, 95% CI 0·22-0·75; p=0·0039), but no difference was found for patients with breast cancer (4·4 months [2·5-8·7] vs 4·2 months [1·8-5·5]; 0·78, 0·43-1·43; p=0·43). Grade 2 or worse adverse events occurred in 21 (41%) patients in the standard-of-care group and 34 (62%) patients in the SBRT group. Nine (16%) patients in the SBRT group had grade 2 or worse toxicities related to SBRT, including gastrointestinal reflux disease, pain exacerbation, radiation pneumonitis, brachial plexopathy, and low blood counts. INTERPRETATION: The trial showed that progression-free survival was increased in the SBRT plus standard-of-care group compared with standard of care only. Oligoprogression in patients with metastatic NSCLC could be effectively treated with SBRT plus standard of care, leading to more than a four-times increase in progression-free survival compared with standard of care only. By contrast, no benefit was observed in patients with oligoprogressive breast cancer. Further studies to validate these findings and understand the differential benefits are warranted. FUNDING: National Cancer Institute.


Subject(s)
Breast Neoplasms , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Radiosurgery , Humans , Female , Carcinoma, Non-Small-Cell Lung/radiotherapy , Carcinoma, Non-Small-Cell Lung/drug therapy , Breast Neoplasms/radiotherapy , Breast Neoplasms/etiology , Lung Neoplasms/radiotherapy , Lung Neoplasms/drug therapy , Positron Emission Tomography Computed Tomography , Antineoplastic Combined Chemotherapy Protocols/adverse effects
4.
J Neurooncol ; 167(3): 509-514, 2024 May.
Article in English | MEDLINE | ID: mdl-38441840

ABSTRACT

PURPOSE: Treatment decisions for leptomeningeal disease (LMD) rely on patient risk stratification, since clinicians lack objective prognostic tools. The introduction of rare cell capture technology for identification of cerebrospinal fluid tumor cells (CSF-TCs), such as CNSide assay, improved the sensitivity of LMD diagnosis, but prognostic value is unknown. This study assesses the prognostic value of CSF-TC density in patients with LMD from solid tumors. METHODS: We conducted a retrospective cohort study of patients with newly diagnosed or previously treated LMD from a single institution who had CNSide assay testing for CSF-TCs from 2020 to 2023. Univariable and multivariable survival analyses were conducted with Cox proportional-hazards modeling. Maximally-selected rank statistics were used to determine an optimal cutpoint for CSF-TC density and survival. RESULTS: Of 31 patients, 29 had CSF-TCs detected on CNSide. Median (interquartile range [IQR]) CSF-TC density was 67.8 (4.7-639) TCs/mL. CSF cytology was positive in 16 of 29 patients with positive CNSide (CNSide diagnostic sensitivity = 93.5%, negative predictive value = 85.7%). Median (IQR) survival from time of CSF-TC detection was 176 (89-481) days. On univariable and multivariable analysis, CSF-TC density was significantly associated with survival. An optimal cutpoint for dichotomizing survival by CSF-TC density was 19.34 TCs/mL. The time-dependent sensitivity and specificity for survival using this stratification were 76% and 67% at 6 months and 65% and 67% at 1 year, respectively. CONCLUSIONS: CSF-TC density may carry prognostic value in patients with LMD from solid tumors. Integrating CSF-TC density into LMD patient risk-stratification may help guide treatment decisions.


Subject(s)
Meningeal Neoplasms , Humans , Retrospective Studies , Female , Male , Prognosis , Middle Aged , Meningeal Neoplasms/cerebrospinal fluid , Meningeal Neoplasms/mortality , Meningeal Neoplasms/diagnosis , Meningeal Neoplasms/pathology , Aged , Adult , Survival Rate , Follow-Up Studies , Neoplasms/cerebrospinal fluid , Neoplasms/mortality , Neoplasms/diagnosis , Neoplasms/pathology , Meningeal Carcinomatosis/cerebrospinal fluid , Meningeal Carcinomatosis/diagnosis , Meningeal Carcinomatosis/mortality , Cell Count
5.
J Neurooncol ; 166(2): 351-357, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38244173

ABSTRACT

PURPOSE: Management of CNS involvement in leukemia may include craniospinal irradiation (CSI), though data on CSI efficacy are limited. METHODS: We retrospectively reviewed leukemia patients who underwent CSI at our institution between 2009 and 2021 for CNS involvement. CNS local recurrence (CNS-LR), any recurrence, progression-free survival (PFS), CNS PFS, and overall survival (OS) were estimated. RESULTS: Of thirty-nine eligible patients treated with CSI, most were male (59%) and treated as young adults (median 31 years). The median dose was 18 Gy to the brain and 12 Gy to the spine. Twenty-five (64%) patients received CSI immediately prior to allogeneic hematopoietic cell transplant, of which 21 (84%) underwent total body irradiation conditioning (median 12 Gy). Among 15 patients with CSF-positive disease immediately prior to CSI, all 14 assessed patients had pathologic clearance of blasts (CNS-response rate 100%) at a median of 23 days from CSI start. With a median follow-up of 48 months among survivors, 2-year PFS and OS were 32% (95% CI 18-48%) and 43% (95% CI 27-58%), respectively. Only 5 CNS relapses were noted (2-year CNS-LR 14% (95% CI 5-28%)), which occurred either concurrently or after a systemic relapse. Only systemic relapse after CSI was associated with higher risk of CNS-LR on univariate analysis. No grade 3 or higher acute toxicity was seen during CSI. CONCLUSION: CSI is a well-tolerated and effective treatment option for patients with CNS leukemia. Control of systemic disease after CSI may be important for CNS local control. CNS recurrence may reflect reseeding from the systemic space.


Subject(s)
Brain Neoplasms , Central Nervous System Neoplasms , Craniospinal Irradiation , Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute , Young Adult , Humans , Male , Female , Brain Neoplasms/therapy , Craniospinal Irradiation/adverse effects , Retrospective Studies , Central Nervous System Neoplasms/radiotherapy , Central Nervous System Neoplasms/etiology , Recurrence , Cranial Irradiation
6.
Semin Neurol ; 43(6): 859-866, 2023 12.
Article in English | MEDLINE | ID: mdl-37989214

ABSTRACT

Leptomeningeal metastases/diseases (LMDs) are a late-stage complication of solid tumor or hematologic malignancies. LMD is spread of cancer cells to the layers of the leptomeninges (pia and arachnoid maters) and subarachnoid space seen in 3 to 5% of cancer patients. It is a disseminated disease which carries with it significant neurologic morbidity and mortality. Our understanding of disease pathophysiology is currently lacking; however, advances are being made. As our knowledge of disease pathogenesis has improved, treatment strategies have evolved. Mainstays of treatment such as radiotherapy have changed from involved-field radiotherapy strategies to proton craniospinal irradiation which has demonstrated promising results in recent clinical trials. Systemic treatment strategies have also improved from more traditional chemotherapeutics with limited central nervous system (CNS) penetration to more targeted therapies with better CNS tumor response. Many challenges remain from earlier clinical detection of disease through improvement of active treatment options, but we are getting closer to meaningful treatment.


Subject(s)
Meningeal Carcinomatosis , Neoplasms , Humans , Meningeal Carcinomatosis/therapy , Meningeal Carcinomatosis/pathology , Meninges/pathology , Biomarkers
7.
Proc Natl Acad Sci U S A ; 117(34): 20397-20403, 2020 Aug 25.
Article in English | MEDLINE | ID: mdl-32788358

ABSTRACT

Organic frameworks (OFs) offer a novel strategy for assembling organic semiconductors into robust networks that facilitate transport, especially the covalent organic frameworks (COFs). However, poor electrical conductivity through covalent bonds and insolubility of COFs limit their practical applications in organic electronics. It is known that the two-dimensional intralayer π∙∙∙π transfer dominates transport in organic semiconductors. However, because of extremely labile inherent features of noncovalent π∙∙∙π interaction, direct construction of robust frameworks via noncovalent π∙∙∙π interaction is a difficult task. Toward this goal, we report a robust noncovalent π∙∙∙π interaction-stacked organic framework, namely πOF, consisting of a permanent three-dimensional porous structure that is held together by pure intralayer noncovalent π∙∙∙π interactions. The elaborate porous structure, with a 1.69-nm supramaximal micropore, is composed of fully conjugated rigid aromatic tetragonal-disphenoid-shaped molecules with four identical platforms. πOF shows excellent thermostability and high recyclability and exhibits self-healing properties by which the parent porosity is recovered upon solvent annealing at room temperature. Taking advantage of the long-range π∙∙∙π interaction, we demonstrate remarkable transport properties of πOF in an organic-field-effect transistor, and the mobility displays relative superiority over the traditional COFs. These promising results position πOF in a direction toward porous and yet conductive materials for high-performance organic electronics.

8.
Int J Cancer ; 150(1): 132-141, 2022 01 01.
Article in English | MEDLINE | ID: mdl-34287840

ABSTRACT

Although cancer is highly heterogeneous, all metastatic cancer is considered American Joint Committee on Cancer (AJCC) Stage IV disease. The purpose of this project was to redefine staging of metastatic cancer. Internal validation of nationally representative patient data from the National Cancer Database (n = 461 357; 2010-2013), and external validation using the Surveillance, Epidemiology and End Results database (n = 106 595; 2014-2015) were assessed using the concordance index for evaluation of survival prediction. A Cox proportional hazards model was used for overall survival by considering identified phenotypes (latent classes) and other confounding variables. Latent class analysis was performed for phenotype identification, where Bayesian information criterion (BIC) and sample-size-adjusted BIC were used to select the optimal number of distinct clusters. Kappa coefficients assessed external cluster validation. Latent class analysis identified five metastatic phenotypes with differences in overall survival (P < .0001): (Stage IVA) nearly exclusive bone-only metastases (n = 59 049, 12.8%; median survival 12.7 months; common in lung, breast and prostate cancers); (IVB) predominant lung metastases (n = 62 491, 13.5%; 11.4 months; common in breast, stomach, kidney, ovary, uterus, thyroid, cervix and soft tissue cancers); (IVC) predominant liver/lung metastases (n = 130 014, 28.2%; 7.0 months; common in colorectum, pancreatic, lung, esophagus and stomach cancers); (IVD) bone/liver/lung metastases predominant over brain (n = 61 004, 13.2%; 5.9 months; common in lung and breast cancers); and (IVE) brain/lung metastases predominant over bone/liver (n = 148 799, 32.3%; 5.7 months; lung cancer and melanoma). Long-term survivors were identified, particularly in Stages IVA-B. A pan-cancer nomogram model to predict survival (STARS: site, tumor, age, race, sex) was created, validated and provides 13% better prognostication than AJCC: 1-month concordance index of 0.67 (95% confidence interval [CI]: 0.66-0.67) vs 0.61 (95% CI: 0.60-0.61). STARS is simple, uses easily accessible variables, better prognosticates survival outcomes and provides a platform to develop novel metastasis-directed clinical trials.


Subject(s)
Neoplasms/pathology , Nomograms , Phenotype , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , Neoplasm Metastasis , Prognosis , Survival Rate , Young Adult
9.
Radiology ; 303(1): 80-89, 2022 04.
Article in English | MEDLINE | ID: mdl-35040676

ABSTRACT

Background Artificial intelligence (AI) applications for cancer imaging conceptually begin with automated tumor detection, which can provide the foundation for downstream AI tasks. However, supervised training requires many image annotations, and performing dedicated post hoc image labeling is burdensome and costly. Purpose To investigate whether clinically generated image annotations can be data mined from the picture archiving and communication system (PACS), automatically curated, and used for semisupervised training of a brain MRI tumor detection model. Materials and Methods In this retrospective study, the cancer center PACS was mined for brain MRI scans acquired between January 2012 and December 2017 and included all annotated axial T1 postcontrast images. Line annotations were converted to boxes, excluding boxes shorter than 1 cm or longer than 7 cm. The resulting boxes were used for supervised training of object detection models using RetinaNet and Mask region-based convolutional neural network (R-CNN) architectures. The best-performing model trained from the mined data set was used to detect unannotated tumors on training images themselves (self-labeling), automatically correcting many of the missing labels. After self-labeling, new models were trained using this expanded data set. Models were scored for precision, recall, and F1 using a held-out test data set comprising 754 manually labeled images from 100 patients (403 intra-axial and 56 extra-axial enhancing tumors). Model F1 scores were compared using bootstrap resampling. Results The PACS query extracted 31 150 line annotations, yielding 11 880 boxes that met inclusion criteria. This mined data set was used to train models, yielding F1 scores of 0.886 for RetinaNet and 0.908 for Mask R-CNN. Self-labeling added 18 562 training boxes, improving model F1 scores to 0.935 (P < .001) and 0.954 (P < .001), respectively. Conclusion The application of semisupervised learning to mined image annotations significantly improved tumor detection performance, achieving an excellent F1 score of 0.954. This development pipeline can be extended for other imaging modalities, repurposing unused data silos to potentially enable automated tumor detection across radiologic modalities. © RSNA, 2022 Online supplemental material is available for this article.


Subject(s)
Artificial Intelligence , Neural Networks, Computer , Brain , Humans , Magnetic Resonance Imaging , Retrospective Studies
10.
J Neurooncol ; 159(3): 609-618, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35896906

ABSTRACT

BACKGROUND: Salvage of recurrent previously irradiated brain metastases (rBrM) is a significant challenge. Resection without adjuvant re-irradiation is associated with a high local failure rate, while reirradiation only partially reduces failure but is associated with greater radiation necrosis risk. Salvage resection plus Cs131 brachytherapy may offer dosimetric and biologic advantages including improved local control versus observation, with reduced normal brain dose versus re-irradiation, however data are limited. METHODS: A prospective registry of consecutive patients with post-stereotactic radiosurgery (SRS) rBrM undergoing resection plus implantation of collagen-matrix embedded Cs131 seeds (GammaTile, GT Medical Technologies) prescribed to 60 Gy at 5 mm from the cavity was analyzed. RESULTS: Twenty patients underwent 24 operations with Cs131 implantation in 25 tumor cavities. Median maximum preoperative diameter was 3.0 cm (range 1.1-6.3). Gross- or near-total resection was achieved in 80% of lesions. A median of 16 Cs131 seeds (range 6-30), with a median air-kerma strength of 3.5 U/seed were implanted. There was one postoperative wound dehiscence. With median follow-up of 1.6 years for survivors, two tumors recurred (one in-field, one marginal) resulting in 8.4% 1-year progression incidence (95%CI = 0.0-19.9). Radiographic seed settling was identified in 7/25 cavities (28%) 1.9-11.7 months post-implantation, with 1 case of distant migration (4%), without clinical sequelae. There were 8 cases of radiation necrosis, of which 4 were symptomatic. CONCLUSIONS: With > 1.5 years of follow-up, intraoperative brachytherapy with commercially available Cs131 implants was associated with favorable local control and toxicity profiles. Weak correlation between preoperative tumor geometry and implanted tiles highlights a need to optimize planning criteria.


Subject(s)
Biological Products , Brachytherapy , Brain Neoplasms , Radiation Injuries , Radiosurgery , Brachytherapy/methods , Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Brain Neoplasms/surgery , Cesium Radioisotopes , Collagen , Humans , Necrosis , Neoplasm Recurrence, Local/complications , Neoplasm Recurrence, Local/radiotherapy , Neoplasm Recurrence, Local/surgery , Radiation Injuries/etiology , Radiosurgery/adverse effects , Radiosurgery/methods , Retrospective Studies , Treatment Outcome
11.
Curr Oncol Rep ; 24(3): 335-342, 2022 03.
Article in English | MEDLINE | ID: mdl-35133614

ABSTRACT

PURPOSE OF REVIEW: Radiation therapy (RT) is a mainstay of treatment for brain metastases from solid tumors. Treatment of these patients is complex and should focus on minimizing symptoms, preserving functional status, and prolonging survival. RECENT FINDINGS: Whole-brain radiotherapy (WBRT) can lead to toxicity, and while it does reduce recurrence in the CNS, this has not been shown to provide a survival benefit. Recent advances focus on reducing the toxicity of WBRT or using more targeted radiation therapy. New paradigms including the use of proton RT for leptomeningeal metastases (LM) and stereotactic radiosurgery (SRS) before craniotomy hold promise in improving treatment efficacy and reducing toxicity. Omission or replacement of WBRT is often safe and the use of SRS is expanding to include patients with more lesions and preoperative RT. Proton RT holds promise for LM. Progress is being made in improving patient-centered outcomes and reducing toxicity for patients with brain metastases.


Subject(s)
Brain Neoplasms , Radiosurgery , Brain Neoplasms/secondary , Cranial Irradiation/adverse effects , Humans , Protons , Treatment Outcome
12.
Proc Natl Acad Sci U S A ; 115(15): 3840-3845, 2018 04 10.
Article in English | MEDLINE | ID: mdl-29581290

ABSTRACT

The with-no-lysine (K) (WNK) signaling pathway to STE20/SPS1-related proline- and alanine-rich kinase (SPAK) and oxidative stress-responsive 1 (OSR1) kinase is an important mediator of cell volume and ion transport. SPAK and OSR1 associate with upstream kinases WNK 1-4, substrates, and other proteins through their C-terminal domains which interact with linear R-F-x-V/I sequence motifs. In this study we find that SPAK and OSR1 also interact with similar affinity with a motif variant, R-x-F-x-V/I. Eight of 16 human inward rectifier K+ channels have an R-x-F-x-V motif. We demonstrate that two of these channels, Kir2.1 and Kir2.3, are activated by OSR1, while Kir4.1, which does not contain the motif, is not sensitive to changes in OSR1 or WNK activity. Mutation of the motif prevents activation of Kir2.3 by OSR1. Both siRNA knockdown of OSR1 and chemical inhibition of WNK activity disrupt NaCl-induced plasma membrane localization of Kir2.3. Our results suggest a mechanism by which WNK-OSR1 enhance Kir2.1 and Kir2.3 channel activity by increasing their plasma membrane localization. Regulation of members of the inward rectifier K+ channel family adds functional and mechanistic insight into the physiological impact of the WNK pathway.


Subject(s)
Potassium Channels, Inwardly Rectifying/chemistry , Potassium Channels, Inwardly Rectifying/metabolism , Protein Serine-Threonine Kinases/metabolism , Amino Acid Motifs , Amino Acid Sequence , Humans , Molecular Sequence Data , Multigene Family , Mutation , Potassium Channels, Inwardly Rectifying/genetics , Protein Domains , Protein Serine-Threonine Kinases/genetics , Sequence Alignment , Signal Transduction
13.
Angew Chem Int Ed Engl ; 60(49): 25746-25752, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34555220

ABSTRACT

We report the palladium-catalyzed gem-difluoroallylation of aryl halides and pseudo halides with 3,3-difluoroallyl boronates in high yield with high regioselectivity, and we report the preparation of the 3,3-difluoroallyl boronate reactants by a copper-catalyzed defluorinative borylation of inexpensive gaseous 3,3,3-trifluoropropene with bis(pinacolato)diboron. The gem-difluoroallylation of aryl and heteroaryl bromides proceeds with low catalyst loading (0.1 mol % [Pd]) and tolerates a wide range of functional groups, including primary alcohols, secondary amines, ethers, ketones, esters, amides, aldehydes, nitriles, halides, and nitro groups. This protocol extends to aryl iodides, chlorides, and triflates, as well as substituted difluoroallyl boronates, providing a versatile synthesis of gem-difluoroallyl arenes that we show to be valuable intermediates to a series of fluorinated building blocks.

14.
Emerg Infect Dis ; 26(4): 826-828, 2020 04.
Article in English | MEDLINE | ID: mdl-32023203

ABSTRACT

In 2018, Babesia microti infection was diagnosed for a 37-year-old man in Singapore who acquired the infection in the United States. This case highlights the recent rise of tickborne infections in the United States and the risk for their spread, because of increasing global interconnectivity, to regions where they are not endemic.


Subject(s)
Babesia microti , Babesiosis , Adult , Babesia microti/genetics , Babesiosis/diagnosis , Babesiosis/epidemiology , Humans , Male , Singapore/epidemiology , United States
15.
Sensors (Basel) ; 19(17)2019 Aug 26.
Article in English | MEDLINE | ID: mdl-31454950

ABSTRACT

Compressive sensing has seen many applications in recent years. One type of compressive sensing device is the Pixel-wise Code Exposure (PCE) camera, which has low power consumption and individual control of pixel exposure time. In order to use PCE cameras for practical applications, a time consuming and lossy process is needed to reconstruct the original frames. In this paper, we present a deep learning approach that directly performs target tracking and classification in the compressive measurement domain without any frame reconstruction. In particular, we propose to apply You Only Look Once (YOLO) to detect and track targets in the frames and we propose to apply Residual Network (ResNet) for classification. Extensive simulations using low quality optical and mid-wave infrared (MWIR) videos in the SENSIAC database demonstrated the efficacy of our proposed approach.

16.
Phys Rev Lett ; 119(21): 217002, 2017 Nov 24.
Article in English | MEDLINE | ID: mdl-29219397

ABSTRACT

We investigate the magnetic phase diagram near the upper critical field of KFe_{2}As_{2} by magnetic torque and specific heat experiments using a high-resolution piezorotary positioner to precisely control the parallel alignment of the magnetic field with respect to the FeAs layers. We observe a clear double transition when the field is strictly aligned in the plane and a characteristic upturn of the upper critical field line, which goes far beyond the Pauli limit at 4.8 T. This provides firm evidence that a Fulde-Ferrell-Larkin-Ovchinnikov state exists in this iron-based KFe_{2}As_{2} superconductor.

18.
Nutr Neurosci ; 19(1): 21-31, 2016.
Article in English | MEDLINE | ID: mdl-26207957

ABSTRACT

OBJECTIVES: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by intracellular accumulations of phosphorylated forms of the microtubule binding protein tau. This study aimed to explore a novel mechanism for enhancing the clearance of these pathological tau species using the green tea flavonoid epigallocatechin-3-gallate (EGCG). EGCG is a potent antioxidant and an activator of the Nrf2 transcriptional pathway. Nrf2 activators including EGCG have shown promise in mitigating amyloid pathology in vitro and in vivo. This study assessed whether EGCG could also alter tau clearance. METHODS: Rat primary cortical neuron cultures were treated on day in vitro 8 with EGCG and analyzed for changes in gene and protein expression using luciferase assay, q-PCR, and western blotting. RESULTS: EGCG treatment led to a significant decrease in the protein levels of three AD-relevant phospho-tau epitopes. Unexpectedly, EGCG does not appear to be facilitating this effect through the Nrf2 pathway or by increasing autophagy in general. However, EGCG did significantly increase mRNA expression of the key autophagy adaptor proteins NDP52 and p62. DISCUSSION: In this study, we show that EGCG enhances the clearance of AD-relevant phosphorylated tau species in primary neurons. Interestingly, this result appears to be independent of both Nrf2 activation and enhanced autophagy - two previously reported mechanisms of phytochemical-induced tau clearance. EGCG did significantly increase expression of two autophagy adaptor proteins. Taken together, these results demonstrate that EGCG has the ability to increase the clearance of phosphorylated tau species in a highly specific manner, likely through increasing adaptor protein expression.


Subject(s)
Catechin/analogs & derivatives , Neurons/cytology , Neurons/drug effects , tau Proteins/metabolism , Animals , Antioxidants/pharmacology , Autophagy/drug effects , Catechin/pharmacology , Cell Line, Tumor , Humans , Microtubules/metabolism , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Neurons/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Phosphorylation , Phytochemicals/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Rats , Rats, Sprague-Dawley , Tea/chemistry
19.
Hum Mol Genet ; 22(16): 3283-95, 2013 Aug 15.
Article in English | MEDLINE | ID: mdl-23612904

ABSTRACT

Cell-mediated regenerative approaches using muscle progenitor cells hold promises for the treatment of many forms of muscle disorders. Their applicability in the clinic, however, is hindered by the low levels of regeneration obtained after transplantation and the large number of cells required to achieve an effect. To better understand the mechanisms that regulate the temporal switch of replicating muscle progenitor cells into terminally differentiated cells and to develop new strategies that could enhance muscle regeneration, we have developed and performed a high-throughput screening (HTS) capable of identifying genes that play active roles during myogenesis. Secondary and tertiary screens were used to confirm the effects of RNAi in vitro and in vivo and to select for candidate hits that significantly increase regeneration into skeletal muscles. Downregulation of cyclin D2 (CCND2) was shown to dramatically enhance myogenic differentiation of muscle progenitor cells and to induce a robust regeneration after cell transplantation into skeletal muscles of dystrophin-deficient mice. Protein interaction network and pathway analysis revealed that CCND2 directly interacts with the cyclin-dependent kinase Cdk4 to inhibit phosphorylation of the retinoblastoma protein (pRb), thus blocking the activation of the myogenic switch during fusion. These studies identify CCND2 as a new key regulator of terminal differentiation in muscle progenitor cells and open new possibilities for the treatment of many forms of muscle disorders characterized by impaired regeneration and loss of muscle mass.


Subject(s)
Cyclin D2/genetics , Cyclin D2/metabolism , Muscle Development/genetics , Myoblasts, Skeletal/physiology , Regeneration , Animals , Cell Fusion , Cells, Cultured , Cyclin-Dependent Kinase 4/genetics , Cyclin-Dependent Kinase 4/metabolism , Mice , Mice, Transgenic , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/metabolism , MyoD Protein/genetics , MyoD Protein/metabolism , Myoblasts, Skeletal/transplantation , Myogenic Regulatory Factor 5/genetics , Myogenic Regulatory Factor 5/metabolism , Myogenin/genetics , Myogenin/metabolism , Protein Interaction Mapping , RNA, Small Interfering , Retinoblastoma Protein/metabolism
20.
Ethn Dis ; 24(1): 116-21, 2014.
Article in English | MEDLINE | ID: mdl-24620458

ABSTRACT

BACKGROUND: To assess medical students' self-reported preparedness to provide care to ethnic minorities, factors that influence preparedness, and attitudes toward cultural competency training. METHODS: A cross-sectional study, which invited University of British Columbia medical students to participate in a survey on student demographics, knowledge and awareness, preparedness and willingness, and personal attitudes. Of 1024, eligible, 301 students consented to study. RESULTS: Students across all year levels felt significantly less ready to provide care for non-English speaking Chinese patients compared to "any" patients. Proficiency in working with interpreters was correlated with readiness, OR 4.447 (1.606-12.315) along with 3rd and 4th year level in medical school, OR 3.550 (1.378-9.141) and 4.424 (1.577-12.415), respectively. Over 80% of respondents reported interest in learning more about the barriers and possible ways of overcoming them. CONCLUSIONS: More opportunities for cultural competency training in the medical curriculum are warranted and would be welcomed by the students.


Subject(s)
Attitude of Health Personnel , Ethnicity , Minority Groups , Students, Medical/statistics & numerical data , British Columbia , China/ethnology , Cross-Sectional Studies , Cultural Competency , Cultural Diversity , Female , Humans , Male , Minority Health , Self Report , Students, Medical/psychology
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