Citations

Background: Low-intensity pulsed ultrasound (LIPUS), as a safe biophysiotherapy, can enhance bone-tendon (B-T) healing in vivo and induce osteogenic or chondrogenic differentiation of mesenchymal stromal cells in vitro. This study aimed to determine whether LIPUS can improve the efficacy of transplanted mesenchymal stromal cells on B-T healing. Hypothesis: LIPUS can induce lineage-specific differentiation of transplanted adipose-derived stromal cells (ASCs) at the B-T healing site, thus resulting in superior healing quality when compared with LIPUS or ASCs alone. Study Design: Controlled laboratory study. Methods: A total of 112 mature rabbits with partial patellectomy in the hindlimb were randomly assigned into mock sonication without ASCs (control), ultrasonication without ASCs (LIPUS), mock sonication with ASCs (ASCs), and ultrasonication with ASCs (LIPUS + ASCs). The treatment time of the mock sonication or ultrasonication was 20 minutes per day. Autologous ASCs were transplanted to the healing site by fibrin glue during the operation, and LIPUS was delivered daily starting at postoperative day 3 until euthanasia. The patella–patellar tendon junctions were postoperatively harvested at 8 and 16 weeks for radiological, histological, and mechanical evaluations. Additionally, 9 animals were used for ASC tracking with mCherry protein. Results: Radiologically, there was more new bone formation and remodeling in the LIPUS + ASCs group as compared with the other groups. Synchrotron radiation micro–computed tomography showed that the LIPUS + ASCs group significantly increased bone volume fraction, trabecular thickness, and trabecular number at the healing site as compared with the other groups at postoperative 8 weeks ( P < .05 for all). Histologically, immunohistochemical staining confirmed that the transplanted mCherry-ASCs can differentiate into osteoblasts and fibrochondrocytic-like cells. Meanwhile, as compared with the other groups, the LIPUS + ASCs group showed more formation and maturity of the fibrocartilage layer and new bone at postoperative weeks 8 and 16 ( P < .05 for all). Biomechanically, the LIPUS + ASCs group showed significantly higher failure load and stiffness versus the other groups at postoperative weeks 8 and 16 ( P < .05 for all). Conclusion: Autologous ASC transplantation stimulated with LIPUS can result in superior B-T healing quality when compared with LIPUS or ASCs alone. Clinical Relevance: This study demonstrates the effectiveness of using ASC transplantation stimulated with LIPUS for B-T healing and provides a foundation for future clinical studies.

PURPOSE The mode of action of targeted cancer agents (TCAs) differs from classic chemotherapy, which leads to concerns about the role of RECIST in evaluating tumor response in trials with TCAs. We investigated the performance of RECIST using a pooled database from 50 clinical trials with at least one TCA. METHODS We examined the impact of the number of target lesions (TLs) on within-patient variability of tumor response. The prognostic effect of TL response (at 12 weeks or on study on the basis of a maximum five TLs) on survival was studied through landmark and time-dependent Cox models adjusted for baseline tumor load, occurrence of new lesions, or unequivocal progression of nontarget disease. RESULTS Data were obtained from 23,259 patients with cancer (36% lung, 28% colorectal, 11% breast, and 25% other); 15,620 received TCAs, predominantly transduction or angiogenesis inhibitors, as a single agent (37%), combined with other TCAs (7%), or as chemotherapy (56%); 28% received chemotherapy only; and 5% received best supportive care or placebo. A total of 17,222 patients contributed to the analyses. Within-patient variability decreased with increasing number of TLs, similarly for TCAs (with/without chemotherapy) and chemotherapy only. Mixed responses occurred proportionally in all treatment classes. Landmark analyses showed an ordinal relationship between percentage change from baseline to 12 weeks and overall survival, and demonstrated a clear distinction between tumor shrinkage and progressive disease according to RECIST. Time-dependent analysis showed no marked improvement in the ability to predict survival on the basis of TL tumor growth compared with nontarget progression or new lesion occurrence, regardless of treatment. Similar results were seen for major tumor types and different classes of TCAs. CONCLUSION This work reinforces that RECIST version 1.1 perform well for response assessment of TCAs.

Background: Accurate identification of stroke cases from electronic health record (EHR) is needed for efficient and valid clinical and epidemiology research. A number of studies have evaluated the validity of using ICD-9 and ICD-10 codes for stroke identification. Previous research results show that sensitivity and positive predictive value (PPV) for stroke identification is the lowest among all other cerebrovascular diseases, with notable differences observed by stroke pathological subtypes. While most prevalent cerebrovascular disease cases can be detected using 430-438/I60-I69 collectively, more accurate and comprehensive stroke phenotyping algorithm is needed to identify incident stroke cases from EHR. In our work, we compared case identification results using ICD-codes exclusively with ICD plus a natural language processing (NLP) algorithm. Methods: We developed the NLP part of our stroke algorithm using a list of expert provided stroke-related keywords, which covers transient ischemic attack (TIA), ischemic stroke, and hemorrhagic stroke. We validated the hybrid (ICD+NLP) algorithm and compared it with ICD-exclusive algorithm in a previously established atrial fibrillation cohort (n=5,062). Clinical notes and ICD codes of all patients after the incident AF event were reviewed by two nurse abstracters to confirm new stroke incidences. All past clinical notes and ICD codes of a subset of patients (n=402) were reviewed to confirm lifetime (prior and current) stroke cases. Manual abstraction results were considered the gold standard for evaluation of ICD only and ICD+NLP automatic extraction. Sensitivity and positive predictive values (PPV) of both algorithms were calculated. Results: Among 5,062 patients, 593 patients were confirmed to have suffered a stroke after atrial fibrillation while 4,469 patients were confirmed with no EHR evidence of stroke after AF. The ICD-exclusive algorithm had a sensitivity of 47.2% and a PPV of 47.8% for detecting new stroke incidences. The hybrid stroke algorithm achieved a sensitivity of 92.4% and a PPV of 60.6% for extraction of incident stroke. For extraction of lifetime stroke cases, the hybrid approach achieved a sensitivity of 93.9% and a PPV of 88.7%. Performance of new stroke incidence extraction is limited because past/current stroke mentions in clinical notes are difficult to distinguish by our NLP algorithm (may be a future direction). Conclusions: We developed and validated a stroke algorithm that performed well for identifying incident and lifetime stroke cases. The addition of NLP into the stroke algorithm improved the sensitivity and PPV of compared to an ICD-exclusive algorithm.

Many hospitalists incorporate point‐of‐care ultrasound (POCUS) into their daily practice to answer specific diagnostic questions or to guide performance of invasive bedside procedures. However, standards for hospitalists in POCUS training and assessment are not yet established. Most internal medicine residency training programs, the major pipeline for incoming hospitalists, have only recently begun to incorporate POCUS in their curricula. The purpose of this document is to inform a broad audience on what POCUS is and how hospitalists are using it. This document is intended to provide guidance for the hospitalists who use POCUS and administrators who oversee its use. We discuss POCUS 1) applications, 2) training, 3) assessments, and 4) program management. Practicing hospitalists must continue to collaborate with their local credentialing bodies to outline requirements for POCUS use. Hospitalists should be integrally involved in decision‐making processes surrounding POCUS program management.

ABSTRACT G 0 /G 1 switch gene 2 (G0S2) is a specific inhibitor of adipose triglyceride lipase (ATGL), the rate‐limiting enzyme for intracellular lipolysis. Recent studies show that G0S2 plays a critical role in promoting triacylglycerol (TG) accumulation in the liver, and its encoding gene is a direct target of a major lipogenic transcription factor liver X receptor (LXR)α. Here we sought to investigate a lipolysis‐independent role of G0S2 in hepatic triglyceride synthesis. Knockdown of G0S2 decreased hepatic TG content in mice with ATGL ablation. Conversely, overexpression of G0S2 promoted fatty acid incorporation into TGs and diacylglycerols in both wild‐type and ATGL‐deficient hepatocytes. Biochemical characterization showed that G0S2 mediates phosphatidic acid synthesis from lysophosphatidic acid (LPA) and acyl‐coenzyme A. In response to a high‐sucrose lipogenic diet, G0S2 is up‐regulated via LXRα and required for the increased TG accumulation in liver. Furthermore, deletion of a distinct 4‐aa motif necessary for the LPA‐specific acyltransferase (LPAAT) activity impaired G0S2's ability to mediate TG synthesis both in vitro and in vivo . These studies identify G0S2 as a dual‐function regulator of lipid metabolism as well as a novel mechanism whereby hepatic TG storage is promoted in response to lipogenic stimulation. In addition to its role as a lipolytic inhibitor, G0S2 is capable of directly promoting TG synthesis by acting as a lipid‐synthesizing enzyme.—Zhang, X., Xie, X., Heckmann, B. L., Saarinen, A. M., Gu, H., Zechner, R., Liu, J. Identification of an intrinsic lysophosphatidic acid acyltransferase activity in the lipolytic inhibitor G 0 /G 1 switch gene 2 (G0S2). FASEB J. 33, 6655–6666 (2019). www.fasebj.org

Abstract MCAM (CD146) is a cell surface adhesion molecule that has been reported to promote cancer development, progression and metastasis and is considered as a potential tumor biomarker and therapeutic target. However, inconsistent reports exist, and its clinical value is yet to be confirmed. Here we took advantage of several large genomic data collections (Genotype-Tissue Expression, The Cancer Genome Atlas and Cancer Cell Line Encyclopedia) and comprehensively analyzed MCAM expression in thousands of normal and cancer samples and cell lines along with their clinical phenotypes and drug response information. Our results show that MCAM is very highly expressed in large vessel tissues while majority of tissues have low or minimal expression. Its expression is dramatically increased in a few tumors but significantly decreased in most other tumors relative to their pairing normal tissues. Increased MCAM expression is associated with a higher tumor stage and worse patient survival for some less common tumors but not for major ones. Higher MCAM expression in primary tumors may be complicated by tumor-associated or normal stromal blood vessels yet its significance may differ from the one from cancer cells. MCAM expression is weakly associated with the response to a few small molecular drugs and the association with targeted anti-BRAF agents suggests its involvement in that pathway which warrants further investigation.

Ex vivo CRISPR/Cas9‐mediated gene editing in hepatocytes using homology‐directed repair (HDR) is a potential alternative curative therapy to organ transplantation for metabolic liver disease. However, a major limitation of this approach in quiescent adult primary hepatocytes is that nonhomologous end‐joining is the predominant DNA repair pathway for double‐strand breaks (DSBs). This study explored the hypothesis that ex vivo hepatocyte culture could reprogram hepatocytes to favor HDR after CRISPR/Cas9‐mediated DNA DSBs. Quantitative PCR (qPCR), RNA sequencing, and flow cytometry demonstrated that within 24 hours, primary mouse hepatocytes in ex vivo monolayer culture decreased metabolic functions and increased expression of genes related to mitosis progression and HDR. Despite the down‐regulation of hepatocyte function genes, hepatocytes cultured for up to 72 hours could robustly engraft in vivo. To assess functionality long‐term, primary hepatocytes from a mouse model of hereditary tyrosinemia type 1 bearing a single‐point mutation were transduced ex vivo with two adeno‐associated viral vectors to deliver the Cas9 nuclease, target guide RNAs, and a 1.2‐kb homology template. Adeno‐associated viral Cas9 induced robust cutting at the target locus, and, after delivery of the repair template, precise correction of the point mutation occurred by HDR. Edited hepatocytes were transplanted into recipient fumarylacetoacetate hydrolase knockout mice, resulting in engraftment, robust proliferation, and prevention of liver failure. Weight gain and biochemical assessment revealed normalization of metabolic function. Conclusion: The results of this study demonstrate the potential therapeutic effect of ex vivo hepatocyte‐directed gene editing after reprogramming to cure metabolic disease in a preclinical model of hereditary tyrosinemia type 1.