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Found 37769 matches. Displaying 1661-1670
Michel AO, Bendet A, Cheleuitte-Nieves C, Yarmohammadi H, Nurili F, Monette S, Michel AO, Bendet A, Basturk O, Askan G, Cheleuitte-Nieves C, Yarmohammadi H, Maxwell AWP, Ziv E, Schachtschneider KM, Gaba RC, Schook LB, Solomon SB, Boas FE
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Transarterial Embolization of Liver Cancer in a Transgenic Pig Model

JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY 2021 APR; 32(4):510-+
Purpose: To develop and characterize a porcine model of liver cancer that could be used to test new locoregional therapies. Materials and Methods: Liver tumors were induced in 18 Oncopigs (transgenic pigs with Cre-inducible TP53R167H and KRASG12D mutations) by using an adenoviral vector encoding the Cre-recombinase gene. The resulting 60 tumors were characterized on multiphase contrast-enhanced CT, angiography, perfusion, micro-CT, and necropsy. Transarterial embolization was performed using 40?120 ?m (4 pigs) or 100?300 ?m (4 pigs) Embosphere microspheres. Response to embolization was evaluated on imaging. Complications were determined based on daily clinical evaluation, laboratory results, imaging, and necropsy. Results: Liver tumors developed at 60/70 (86%) inoculated sites. Mean tumor size was 2.1 cm (range, 0.3?4 cm) at 1 week. Microscopically, all animals developed poorly differentiated to undifferentiated carcinomas accompanied by a major inflammatory component, which resembled undifferentiated carcinomas of the human pancreatobiliary tract. Cytokeratin and vimentin expression confirmed epithelioid and mesenchymal differentiation, respectively. Lymph node, lung, and peritoneal metastases were seen in some cases. On multiphase CT, all tumors had a hypovascular center, and 17/60 (28%) had a hypervascular rim. After transarterial embolization, noncontrast CT showed retained contrast medium in the tumors. Follow-up contrast-enhanced scan showed reduced size of tumors after embolization using either 40?120 ?m or 100?300 ?m Embosphere microspheres, while untreated tumors showed continued growth. Conclusions: Liver tumors can be induced in a transgenic pig and can be successfully treated using bland embolization.
Islam MS, Yang XW, Euler CW, Han XQ, Liu JH, Hossen I, Zhou Y, Li JQ
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Application of a novel phage ZPAH7 for controlling multidrug-resistant Aeromonas hydrophila on lettuce and reducing biofilms

FOOD CONTROL 2021 APR; 122(?):? Article 107785
Aeromonas hydrophila is an important pathogenic bacterium that causes foodborne illness worldwide. In this study, virulent phages from the sediment of a fish farm were propagated and isolated on a multidrug-resistant strain of A. hydrophila, ZYAH75. One phage, designated as ZPAH7, featured a unique turbid halo around a clear plaque on the bacterial lawn (indicative of potential depolymerase activity), and was selected for further analysis. ZPAH7 was classified as podophage by morphological and genomic methods. Further comparisons of genome nucleotide similarity, ratios of homologous proteins and phylogenetic relatedness among the terminase large subunit and major capsid proteins of similar phage deposited in GENBANK, led us to propose a new genus, ZPAH7virus, in the Autographivirinae subfamily of Podoviridae. ZPAH7 had an adsorption rate of 79% in 5 min, an eclipse period of 15 min, a latent period of 25 min, and a burst size of 148 +/- 9 PFU/cell. Antimicrobial application experiments showed that ZPAH7 lead to significantly reduction on A. hydrophila on lettuce. Additionally, ZPAH7 was able to inhibit biofilm formation, as well as degrade and kill bacteria in established biofilms. Furthermore, lytic activity of ZPAH7 remained stable across a wide range of temperatures and pH measurements. These results suggest ZPAH7 could be used as a potential biological control agent against A. hydrophila on food and/or biofilms on food contact surfaces.
Gaebler C, Wang ZJ, Lorenzi JCC, Muecksch F, Finkin S, Tokuyama M, Cho A, Jankovic M, Schaefer-Babajew D, Oliveira TY, Cipolla M, Viant C, Barnes CO, Bram Y, Breton G, Hagglof T, Mendoza P, Hurley A, Turroja M, Gordon K, Millard KG, Ramos V, Schmidt F, Weisblum Y, Jha D, Tankelevich M, Martinez-Delgado G, Yee J, Patel R, Dizon J, Unson-O'Brien C, Shimeliovich I, Robbiani DF, Zhao Z, Gazumyan A, Schwartz RE, Hatziioannou T, Bjorkman PJ, Mehandru S, Bieniasz PD, Caskey M, Nussenzweig MC
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Evolution of antibody immunity to SARS-CoV-2

NATURE 2021 MAR 25; 591(7851):639-644
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected 78 million individuals and is responsible for over 1.7 million deaths to date. Infection is associated with the development of variable levels of antibodies with neutralizing activity, which can protect against infection in animal models(1,2). Antibody levels decrease with time, but, to our knowledge, the nature and quality of the memory B cells that would be required to produce antibodies upon reinfection has not been examined. Here we report on the humoral memory response in a cohort of 87 individuals assessed at 1.3 and 6.2 months after infection with SARS-CoV-2. We find that titres of IgM and IgG antibodies against the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2 decrease significantly over this time period, with IgA being less affected. Concurrently, neutralizing activity in plasma decreases by fivefold in pseudotype virus assays. By contrast, the number of RBD-specific memory B cells remains unchanged at 6.2 months after infection. Memory B cells display clonal turnover after 6.2 months, and the antibodies that they express have greater somatic hypermutation, resistance to RBD mutations and increased potency, indicative of continued evolution of the humoral response. Immunofluorescence and PCR analyses of intestinal biopsies obtained from asymptomatic individuals at 4 months after the onset of coronavirus disease 2019 (COVID-19) revealed the persistence of SARS-CoV-2 nucleic acids and immunoreactivity in the small bowel of 7 out of 14 individuals. We conclude that the memory B cell response to SARS-CoV-2 evolves between 1.3 and 6.2 months after infection in a manner that is consistent with antigen persistence.
Maguire OA, Ackerman SE, Szwed SK, Maganti AV, Marchildon F, Huang XJ, Kramer DJ, Rosas-Villegas A, Gelfer RG, Turner LE, Ceballos V, Hejazi A, Samborska B, Rahbani JF, Dykstra CB, Annis MG, Luo JD, Carroll TS, Jiang CS, Dannenberg AJ, Siegel PM, Tersey SA, Mirmira RG, Kazak L, Cohen P
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Creatine-mediated crosstalk between adipocytes and cancer cells regulates obesity-driven breast cancer

CELL METABOLISM 2021 MAR 2; 33(3):499-512.e6
Obesity is a major risk factor for adverse outcomes in breast cancer; however, the underlying molecular mechanisms have not been elucidated. To investigate the role of crosstalk between mammary adipocytes and neoplastic cells in the tumor microenvironment (TME), we performed transcriptomic analysis of cancer cells and adjacent adipose tissue in a murine model of obesity-accelerated breast cancer and identified glycine amidinotransferase (Gatm) in adipocytes and Acsbg1 in cancer cells as required for obesity-driven tumor progression. Gatm is the rate-limiting enzyme in creatine biosynthesis, and deletion in adipocytes attenuated obesity-driven tumor growth. Similarly, genetic inhibition of creatine import into cancer cells reduced tumor growth in obesity. In parallel, breast cancer cells in obese animals upregulated the fatty acyl-CoA synthetase Acsbg1 to promote creatine-dependent tumor progression. These findings reveal key nodes in the crosstalk between adipocytes and cancer cells in the TME necessary for obesity-driven breast cancer progression.
Cai BL, Li ZH, Ma MT, Zhang J, Kong SF, Abdalla BA, Xu HP, Jebessa E, Zhang XQ, Lawal RA, Nie QH
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Long noncoding RNA SMUL suppresses SMURF2 production-mediated muscle atrophy via nonsense-mediated mRNA decay

MOLECULAR THERAPY-NUCLEIC ACIDS 2021 MAR 5; 23(?):498-+
As the world population grows, muscle atrophy leading to muscle wasting could become a bigger risk. Long noncoding RNAs (lncRNAs) are known to play important roles in muscle growth and muscle atrophy. Meanwhile, it has recently come to light that many putative small open reading frames (sORFs) are hidden in lncRNAs; however, their translational capabilities and functions remain unclear. In this study, we uncovered 104 myogenic-associated lncRNAs translated, in at least a small peptide, by integrated transcriptome and proteomic analyses. Furthermore, an upstream ORF (uORF) regulatory network was constructed, and a novel muscle atrophy-associated lncRNA named SMUL (Smad ubiquitin regulatory factor 2 [SMURF2] upstream lncRNA) was identified. SMUL was highly expressed in skeletal muscle, and its expression level was down regulated during myoblast differentiation. SMUL promoted myoblast proliferation and suppressed differentiation in vitro. In vivo, SMUL induced skeletal muscle atrophy and promoted a switch from slow-twitch to fast-twitch fibers. In the meantime, translation of the SMUL sORF disrupted the stability of SMURF2 mRNA. Mechanistically, SMUL restrained SMURF2 production via nonsense-mediated mRNA decay (NMD), participating in the regulation of the transforming growth factor beta (TGF-beta)/SMAD pathway and further regulating myogenesis and muscle atrophy. Taken together, these results suggest that SMUL could be a novel therapeutic target for muscle atrophy.
Abdalla T, Mansour M, Bouazzi D, Lowes MA, Jemec GBE, Alavi A
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Therapeutic Drug Monitoring in Patients with Suboptimal Response to Adalimumab for Hidradenitis Suppurativa: A Retrospective Case Series

AMERICAN JOURNAL OF CLINICAL DERMATOLOGY 2021; 22(2):275-283
Background Adalimumab, a tumor necrosis factor-alpha inhibitor, is a biologic used for the treatment of moderate-to-severe hidradenitis suppurativa (HS). It is well known that patients may experience loss of efficacy from its use in other conditions, and it is suggested that developing a strategy for therapeutic drug monitoring (TDM) may help secure optimal clinical outcomes. Objectives We sought to determine serum adalimumab concentrations and anti-adalimumab antibody (AAA) status in patients with moderate-to-severe HS. Methods A retrospective case series of 38 patients with suboptimal response to adalimumab 40 mg weekly was conducted at a community dermatology clinic. Adalimumab serum trough levels, AAA status, and inflammatory biomarkers were collected. Blood was drawn on identification of suboptimal response (after a minimum of 12 weeks) and was collected once prior to receiving the next scheduled dose. Kruskal-Wallis and Chi-squared tests were used for data analysis. Results A total of 38 patients had a median adalimumab trough concentration of 8.76 (interquartile range [IQR] 1.3-12.5) mu g/mL. The median duration of adalimumab therapy of all patients was 21 (IQR 12-24) months. AAAs were detected in nine patients (24%), and all had subtherapeutic serum concentrations (< 6 mu g/mL). Patients who were AAA+ had a significantly lower median adalimumab concentration than those who were AAA- (0.02 mu g/mL [range 0.02-0.81] vs. 10.14 [range 0.76-48.00]; p = 0.0006). Conclusion Patients with AAAs had significantly lower serum adalimumab levels. The current study suggests that TDM may identify underlying reasons for suboptimal response and detect patients who may benefit from dose optimization strategies.
McMahon JH, Zerbato JM, Lau JSY, Lange JL, Roche M, Tumpach C, Dantanarayana A, Rhodes A, Chang J, Rasmussen TA, Mackenzie CA, Alt K, Hagenauer M, Roney J, O'Bryan J, Carey A, McIntyre R, Beech P, O'Keefe GJ, Wichmann CW, Scott FE, Guo N, Lee ST, Liu ZQ, Caskey M, Nussenzweig MC, Donnelly PS, Egan G, Hagemeyer CE, Scott AM, Lewin SR
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A clinical trial of non-invasive imaging with an anti-HIV antibody labelled with copper-64 in people living with HIV and uninfected controls

EBIOMEDICINE 2021 MAR; 65(?):? Article 103252
Background: A research priority in finding a cure for HIV is to establish methods to accurately locate and quantify where and how HIV persists in people living with HIV (PLWH) receiving suppressive antiretroviral therapy (ART). Infusing copper-64 (Cu-64) radiolabelled broadly neutralising antibodies targeting HIV envelope (Env) with CT scan and positron emission tomography (PET) identified HIV Env in tissues in SIV infected non-human primates . We aimed to determine if a similar approach was effective in people living with HIV (PLWH). Methods: Unmodified 3BNC117 was compared with 3BNC117 bound to the chelator MeCOSar and Cu-64 (Cu-64-3BNC117) in vitro to assess binding and neutralization. In a clinical trial Cu-64-3BNC117 was infused into HIV uninfected (Group 1), HIV infected and viremic (viral load, VL >1000 c/mL; Group 2) and HIV infected aviremic (VL <20 c/mL; Group 3) participants using two dosing strategies: high protein (3mg/kg unlabeled 3BNC117 combined with <5mg Cu-64-3BNC117) and trace (<5mg Cu-64-3BNC117 only). All participants were screened for 3BNC117 sensitivity from virus obtained from viral outgrowth. Magnetic resonance imaging (MRI)/PET and pharmacokinetic assessments (ELISA for serum 3BNC117 concentrations and gamma counting for Cu-64) were performed 1, 24-and 48-hours post dosing. The trial (clincialtrials.gov NCT03063788) primary endpoint was comparison of PET standard uptake values (SUVs) in regions of interest (e.g lymph node groups and gastrointestinal tract). Findings: Comparison of unmodified and modified 3BNC117 in vitro demonstrated no difference in HIV binding or neutralisation. 17 individuals were enrolled of which 12 were dosed including Group 1 (n=4, 2 high protein, 2 trace dose), Group 2 (n=6, 2 high protein, 4 trace) and Group 3 (n=2, trace only). HIV+ participants had a mean CD4 of 574 cells/microL and mean age 43 years. There were no drug related adverse effects and no differences in tissue uptake in regions of interest (e.g lymph node gut, pharynx) between the 3 groups. In the high protein dosing group, serum concentrations of 3BNC117 and gamma counts were highly correlated demonstrating that Cu-64-3BNC117 remained intact in vivo. Interpretation: In PLWH on or off ART, the intervention of infusing Cu-64-3BNC117 and MRI/PET imaging over 48 hours, was unable to detect HIV-1 env expression in vivo. Future studies should investigate alternative radiolabels such as zirconium which have a longer half-life in vivo. Funding: Funded by the Alfred Foundation, The Australian Centre for HIV and Hepatitis Virology Research with additional support from the Division of AIDS, National Institute of Allergy and Infectious Disease, US National Institutes of Health (USAI126611). JHM and SRL are supported by the Australian National Health and Medical Research Council. (C) The Author(s). Published by Elsevier B.V.
Gaebler C, Falcinelli SD, Stoffel E, Read J, Murtagh R, Oliveira TY, Ramos V, Lorenzi JCC, Kirchherr J, James KS, Allard B, Baker C, Kuruc JD, Caskey M, Archin NM, Siliciano RF, Margolis DM, Nussenzweig MC
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Sequence Evaluation and Comparative Analysis of Novel Assays for Intact Proviral HIV-1 DNA

JOURNAL OF VIROLOGY 2021 MAR; 95(6):? Article e01986-20
The HIV proviral reservoir is the major barrier to cure. The predominantly replication-defective proviral landscape makes the measurement of virus that is likely to cause rebound upon antiretroviral therapy (ART)-cessation challenging. To address this issue, novel assays to measure intact HIV proviruses have been developed. The intact proviral DNA assay (IPDA) is a high-throughput assay that uses two probes to exclude the majority of defective proviruses and determine the frequency of intact proviruses, albeit without sequence confirmation. Quadruplex PCR with four probes (Q4PCR) is a lower-throughput assay that uses limiting dilution long-distance PCR amplification followed by quantitative PCR (qPCR) and near-full-length genome sequencing (nFGS) to estimate the frequency of sequence-confirmed intact proviruses and provide insight into their clonal composition. To explore the advantages and limitations of these assays, we compared IPDA and Q4PCR measurements from 39 ART-suppressed people living with HIV. We found that IPDA and Q4PCR measurements correlated with one another, but frequencies of intact proviral DNA differed by approximately 19-fold. This difference may be in part due to inefficiencies in long-distance PCR amplification of proviruses in Q4PCR, leading to underestimates of intact proviral frequencies. In addition, nFGS analysis within Q4PCR explained that some of this difference is explained by proviruses that are classified as intact by IPDA but carry defects elsewhere in the genome. Taken together, this head-to-head comparison of novel intact proviral DNA assays provides important context for their interpretation in studies to deplete the HIV reservoir and shows that together the assays bracket true reservoir size. IMPORTANCE The intact proviral DNA assay (IPDA) and quadruplex PCR (Q4PCR) represent major advances in accurately quantifying and characterizing the replication-competent HIV reservoir. This study compares the two novel approaches for measuring intact HIV proviral DNA in samples from 39 antiretroviral therapy (ART) suppressed people living with HIV, thereby informing ongoing efforts to deplete the HIV reservoir in cure-related trials.
Merkenschlager J, Finkin S, Ramos V, Kraft J, Cipolla M, Nowosad CR, Hartweger H, Zhang WZ, Olinares PDB, Gazumyan A, Oliveira TY, Chait BT, Nussenzweig MC
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Dynamic regulation of T-FH selection during the germinal centre reaction

NATURE 2021 MAR 18; 591(7850):458-463
The germinal centre is a dynamic microenvironment in which B cells that express high-affinity antibody variants produced by somatic hypermutation are selected for clonal expansion by limiting the numbers of T follicular helper cells(1,2). Although much is known about the mechanisms that control the selection of B cells in the germinal centre, far less is understood about the clonal behaviour of the T follicular helper cells that help to regulate this process. Here we report on the dynamic behaviour of T follicular helper cell clones during the germinal centre reaction. We find that, similar to germinal centre B cells, T follicular helper cells undergo antigen-dependent selection throughout the germinal centre reaction that results in differential proliferative expansion and contraction. Increasing the amount of antigen presented in the germinal centre leads to increased division of T follicular helper cells. Competition between T follicular helper cell clones is mediated by the affinity of T cell receptors for peptide-major-histocompatibility-complex ligands. T cells that preferentially expand in the germinal centre show increased expression of genes downstream of the T cell receptor, such as those required for metabolic reprogramming, cell division and cytokine production. These dynamic changes lead to marked remodelling of the functional T follicular helper cell repertoire during the germinal centre reaction.
Alvim R, Nagar K, Das S, Lebdai S, Wong N, Somma A, Hughes C, Thomas J, Monette S, Scherz A, Kim K, Grimm J, Coleman JA
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Positron Emission Tomography/Computed Tomography with Gallium-68-labeled Prostate-specific Membrane Antigen Detects Relapse After Vascular-targeted Photodynamic Therapy in a Prostate Cancer Model

EUROPEAN UROLOGY FOCUS 2021 MAR; 7(2):472-478
Background: Evaluating the efficacy of focal therapy for prostate cancer is limited by current approaches and may be improved with biological imaging techniques. Objective: We assessed whether positron emission tomography/computed tomography with gallium-68-labeled prostate-specific membrane antigen (Ga-68-PSMA PET/CT) can be used to predict relapse after vascular-targeted photodynamic therapy (VTP). Design, setting, and participants: A total of 1 x 10(6) LNCaP cells were grafted subcutaneously in the flanks of 6-8-wk-old SCID mice. Of 24 mice with measurable tumors 6 wk after tumor implantation, 20 were treated with VTP (150 mW/cm(2)) to ablate the tumors. Blood prostate-specific antigen (PSA) levels were assessed, and Ga-68-PSMA PET/CT images were performed 1 d before VTP and 1 and 4 wk after. Outcome measurements and statistical analysis: Local tumor relapse was evaluated by histology, and tumors were analyzed by prostate-specific membrane antigen (PSMA) and PSA immunohistochemistry. T tests and Kruskal-Wallis tests were used to determine significance. Results and limitations: Four weeks after VTP, 11 (65%) mice had complete responses and six (35%) had tumor relapses confirmed by histology (hematoxylin and eosin, and PSMA immunohistochemistry). All mice with local relapse had positive Ga-68-PSMA PET/CT findings 4 wk after VTP; all complete responders did not. One week after VTP, the relapse detection sensitivity of Ga-68-PSMA PET/CT was 75%, whereas the sensitivity of PSA was only 33%. Compared with controls, relapsed tumors had a three-fold reduction in the number of cells with strong PSA staining by immunohistochemistry (1.5% vs 4.5%; p = 0.01). Conclusions: In a preclinical prostate cancer model, we show that Ga-68-PSMA PET/CT can identify and predict relapse earlier than blood PSA level. These findings support further testing in clinical trials. Patient summary: Positron emission tomography/computed tomography with gallium-68-labeled prostate-specific membrane antigen may be used to follow and evaluate treatment outcomes in men who receive focal therapy for prostate cancer. (C) 2019 Published by Elsevier B.V. on behalf of European Association of Urology.