16 research outputs found
Periorbital edema secondary to imatinib mesylate
Collin M McClelland, George J Harocopos, Philip L CusterSchool of Medicine, Washington University, St. Louis, MO, USAAbstract: Imatinib mesylate (Gleevec®) is a well-established pharmacologic treatment for all phases of chronic myeloid leukemia and for advanced gastrointestinal stromal tumors (GISTs). Edema-related side effects are relatively common in imatinib therapy with the periocular skin representing one of the most common sites for localized edema. While the adverse effect of periorbital edema with imatinib is well documented in the oncology literature, there is limited reference to this common reaction in the ophthalmology literature. We report two patients with upper eyelid edema associated with imatinib therapy who required surgical intervention to ameliorate significant visual field obstruction. We highlight the details of each case including the histopathologic findings of excised redundant skin followed by a thorough review of the literature on imatinib related periorbital edema.Keywords: imatinib mesylate, gleevec, edema, periorbital edema, tyrosine kinase inhibito
Oncogenic Gq/11 signaling acutely drives and chronically sustains metabolic reprogramming in uveal melanoma
Metabolic reprogramming has been shown to occur in uveal melanoma (UM), the most common intraocular tumor in adults. Mechanisms driving metabolic reprogramming in UM are poorly understood. Elucidation of these mechanisms could inform development of new therapeutic strategies for metastatic UM, which has poor prognosis because existing therapies are ineffective. Here, we determined whether metabolic reprogramming is driven by constitutively active mutant α-subunits of the heterotrimeric G proteins Gq or G11 (Gq/11), the oncogenic drivers in ∼90% of UM patients. Using PET-computed tomography imaging, microphysiometry, and GC/MS, we found that inhibition of oncogenic Gq/11 with the small molecule FR900359 (FR) attenuated glucose uptake by UM cells in vivo and in vitro, blunted glycolysis and mitochondrial respiration in UM cell lines and tumor cells isolated from patients, and reduced levels of several glycolytic and tricarboxylic acid cycle intermediates. FR acutely inhibited glycolysis and respiration and chronically attenuated expression of genes in both metabolic processes. UM therefore differs from other melanomas that exhibit a classic Warburg effect. Metabolic reprogramming in UM cell lines and patient samples involved protein kinase C and extracellular signal-regulated protein kinase 1/2 signaling downstream of oncogenic Gq/11. Chronic administration of FR upregulated expression of genes involved in metabolite scavenging and redox homeostasis, potentially as an adaptive mechanism explaining why FR does not efficiently kill UM tumor cells or regress UM tumor xenografts. These results establish that oncogenic Gq/11 signaling is a crucial driver of metabolic reprogramming in UM and lay a foundation for studies aimed at targeting metabolic reprogramming for therapeutic development
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Suppressed HIV antibody responses following exposure to antiretrovirals – evidence from PrEP randomized trials and early antiretroviral treatment initiation studies
BACKGROUND: Exposure to antiretrovirals at or early after HIV acquisition can suppress viral replication and blunt antibody (Ab) responses; a reduced HIV detectability could impact diagnosis and blood donation screening. METHODS: We used three antigen (Ag)/Ab assays and one nucleic acid test (NAT) to analyze samples collected in pre-exposure prophylaxis (PrEP) trials (iPrEx; Partners PrEP) before infection detection by Ab-only rapid diagnostic tests (RDTs), and in early antiretroviral treatment (ART) initiation studies (RV254; SIPP). RESULTS: Reactivity using NAT and Ag/Ab assays in samples collected up to 8 weeks prior to the first reactive RDT from 251 PrEP trials participants varied between 49-61% for active PrEP users and between 27-37% for placebo users. Among RV254 participants, reactivity in Ag/Ab assays was <100% at all timepoints, and lower among those initiating ART earlier. Seroreversions occurred for 29% (16/55), and blood donation screening with NAT and Ag/Ab assays could have missed up to 36% (20/55) of RV254 participants. For SIPP participants, who started ART at later timepoints, Ag/Ab assays identified infections with no evidence of reactivity waning. CONCLUSION: PrEP and early ART initiation can delay or reduce HIV detectability. Considerations for the implementation of NAT and Ag/Ab tests in PrEP/PEP programs relying on Ab-only RDTs should be balanced according to feasibility and public health impact. While blood transfusion services using Ab-only RDTs for HIV screening should adopt higher sensitivity tests, surveillance and further research are needed to determine the need for novel HIV testing algorithms for those already using NAT and Ag/Ab screening assays