Publications by authors named "Benjamin D Medina"

Objective: Shape-sensing robotic-assisted bronchoscopy is an emerging technology for the sampling of pulmonary lesions. We seek to characterize the shape-sensing robotic-assisted bronchoscopy learning curve at an academic center.

Methods: Shape-sensing robotic-assisted bronchoscopy procedures performed by 9 proceduralists at a single institution were analyzed.

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γδ T cells are a rare but potent subset of T cells with pleiotropic functions. They commonly reside within tumors but the response of γδ T cells to tyrosine kinase inhibition is unknown. To address this, we studied a genetically engineered mouse model of gastrointestinal stromal tumor (GIST) driven by oncogenic Kit signaling that responds to the Kit inhibitor imatinib.

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Targeted therapy with a tyrosine kinase inhibitor (TKI) such as imatinib is effective in treating gastrointestinal stromal tumor (GIST), but it is rarely curative. Despite the presence of a robust immune CD8+ T-cell infiltrate, combining a TKI with immune-checkpoint blockade (ICB) in advanced GIST has achieved only modest effects. To identify limitations imposed by imatinib on the antitumor immune response, we performed bulk RNA sequencing (RNA-seq), single-cell RNA-seq, and flow cytometry to phenotype CD8+ T-cell subsets in a genetically engineered mouse model of GIST.

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Background: The COVID-19 pandemic overwhelmed New York City hospitals early in the pandemic. Shortages of ventilators and sedatives prompted tracheostomy earlier than recommended by professional societies. This study evaluates the impact of percutaneous dilational tracheostomy (PDT) in COVID+ patients on critical care capacity.

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Type I IFNs are implicated in tumor immunogenicity and response to systemic therapy, but their interaction with oncogene signaling is not well understood. Here, we studied oncogenic KIT, which drives gastrointestinal stromal tumor (GIST), the most common sarcoma. Using mouse models of GIST, we found that KIT inhibition reduced type I IFN production and signaling, which downregulated tumor MHC class I expression.

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Article Synopsis
  • Gastrointestinal stromal tumors (GISTs) are the most common type of sarcoma found in the gastrointestinal tract, primarily caused by mutations in the KIT receptor tyrosine kinase, specifically the exon 11 KIT V559Δ mutation.
  • Imatinib is a key treatment for GIST, but patients often develop resistance due to mutations like KIT V654A, prompting the need for alternative therapies.
  • Researchers created a mouse model with the double KIT mutation (V558Δ;V653A) to study its effects, finding that this mutation increased tumor growth and resistance to imatinib while showing better response to the drug cabozantinib.
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Background And Objectives: Metastasectomy for melanoma provides durable disease control in carefully selected patients. Similarly, BRAF-targeted and immune checkpoint inhibition has improved median overall survival (OS) in metastatic patients. We hypothesized that there is an increasing role for metastasectomy in melanoma patients responding to these therapies.

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Patients with pancreatic ductal adenocarcinoma do not benefit from checkpoint blockade. However, human tumors harbor evidence of adaptive immunity in clonally expanded T-cell populations. Immune intact modeling of human tumors identifies stromal sequestration as a mechanism of immune escape.

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Article Synopsis
  • Gastrointestinal stromal tumor (GIST) is a type of cancer that starts from a mutation in a gene that helps control cell growth.
  • In studies with mice and humans, certain immune cells (dendritic cells) were found to help T cells fight the tumor, but treatment with a drug called imatinib (used to fight GIST) can reduce these helpful cells over time.
  • The study also discovered that keeping these immune cells around while using imatinib could make the treatment more effective against the tumor.
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Gastrointestinal stromal tumor (GIST) is the most common human sarcoma, frequently characterized by an oncogenic mutation in the KIT or platelet-derived growth factor receptor alpha (PDGFRA) genes. We performed RNA sequencing of 75 human GIST tumors from 75 patients, comprising the largest cohort of GISTs sequenced to date, in order to discover differences in the immune infiltrates of KIT and PDGFRA-mutant GIST. Through bioinformatics, immunohistochemistry, and flow cytometry, we found that PDGFRA-mutant GISTs harbored more immune cells with increased cytolytic activity when compared to KIT-mutant GISTs.

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Tyrosine kinase inhibition of gastrointestinal stromal tumors (GIST) is effective but typically culminates in resistance and is rarely curative. Immunotherapy has potential application to GIST, as we previously showed that T-cell checkpoint blockade increases the antitumor effects of imatinib. Here, we showed that ligation of CD40 using an agonistic antibody (anti-CD40) activated tumor-associated macrophages (TAMs) in a knock-in mouse model of GIST harboring a germline mutation in exon 11.

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Gastrointestinal stromal tumor (GIST) is the most common sarcoma, often resulting from a or platelet-derived growth factor receptor alpha () mutation. The lineage transcription factor ETV1 is expressed similarly in GISTs regardless of malignant potential. Although the related transcription factor ETV4 has been associated with metastasis and tumor progression in other cancers, its role in GIST is unknown.

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Imatinib dramatically reduces gastrointestinal stromal tumor (GIST) F-FDG uptake, providing an early indicator of treatment response. Despite decreased glucose internalization, many GIST cells persist, suggesting that alternative metabolic pathways are used for survival. The role of mitochondria in imatinib-treated GIST is largely unknown.

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Gastrointestinal stromal tumor (GIST) is the most common type of sarcoma and usually harbors either a or mutation. However, the molecular basis for tumor malignancy is not well defined. Although the Wnt/β-catenin signaling pathway is important in a variety of cancers, its role in GIST is uncertain.

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Purpose: Tyrosine kinase inhibitors are effective in gastrointestinal stromal tumors (GISTs) but often are of transient benefit as resistance commonly develops. Immunotherapy, particularly blockade of the inhibitory receptor programmed death 1 (PD-1) or the ligand programmed death ligand 1 (PD-L1), has shown effectiveness in a variety of cancers. The functional effects of PD-1/PD-L1 blockade are unknown in GISTs.

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