The Current Landscape for METex14 Skipping Mutations in Non-Small Cell Lung Cancer.

Capmatinib and tepotinib received US Food and Drug Administration (FDA) approval for mesenchymal-epithelial transition (MET) exon 14 (METex14) skipping alteration in 2020 and 2021, respectively. Capmatinib was FDA approved in May 2020 under accelerated approval for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have a mutation that leads to METex14 skipping. Accelerated approval was based on overall response rate and response duration to capmatinib, and it was granted orphan drug and breakthrough therapy designation. Capmatinib is a potent selective kinase inhibitor of the MET receptor, crosses the blood-brain barrier, and has shown low-grade adverse events. Based on phase II data, capmatinib demonstrated an overall response rate (ORR) of 41% and a median duration of response (DOR) of 9.7 months in those who previously received one or two lines of therapy. In treatment-naive patients, capmatinib demonstrated a 68% ORR with a median DOR of 12.6 months. The FDA also granted accelerated approval to tepotinib for adult patients with metastatic NSCLC harboring METex14 skipping alteration. Accelerated approval for tepotinib was based on an ORR of 43% with a median DOR of 10.8 months in treatment-naive patients. Among previously treated patients, the ORR was 43% with a median DOR of 11.1 months. Continued approval for capmatinib and tepotinib is contingent upon confirmatory trials. Both agents are now considered first-line therapy or a subsequent therapy option in patients with metastatic NSCLC who are positive for METex14 skipping alterations.

Ultrasensitive Quantification of Cytokine Proteins in Single Lymphocytes From Human Blood Following ex-vivo Stimulation.

In this study we demonstrate the feasibility of direct, quantitative measurement of cytokine proteins in single human CD8 lymphocytes from fresh peripheral blood of healthy donors following a brief ex vivo stimulation. Cytokine-secreting cells were identified using cell surface "catch" reagents and single cell data were obtained by sorting of individual cytokine-secreting cells into 96 well plates containing lysis buffer followed by analysis using ultrasensitive immunoassays for interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α). CD8 cells negative for cytokine production, as determined by the cell surface catch reagents were used as negative controls. Furthermore, studies were undertaken to compare the mean fluorescence intensity (MFI) values of cytokine staining by flow cytometry with the quantification of cytokines using the current method. This study demonstrates that it is feasible to quantify cytokines from individual primary cells. A shift from qualitative to quantitative determinations of cytokine protein levels in single cells will permit more precise and reproducible studies of heterogeneity in the immune system and can be accomplished with readily available instrumentation.

Serial Swept-Source Optical Coherence Tomography Features of Gentamicin Macular Toxicity: A Glimpse Into the Injury Cascade.

The early clinical manifestations of macular infarction secondary to subconjunctival gentamicin (Gentak; Akorn, Lake Forest, IL) use in an aphakic eye were documented sequentially on swept-source optical coherence tomography (OCT) and fundus fluorescein angiography. The first recorded event after drug toxicity was macular detachment, along with disorganization of outer retinal layers in about 12 hours. The changes in inner retinal layers occurred after 36 hours had elapsed. OCT-documented initial damage to outer retinal layers could be due to the susceptibility of first order retinal neurons, followed by subsequent inner retinal layer involvement and ischemia. This helps in understanding pathogenesis of a catastrophic complication of subconjunctival gentamicin injection commonly used for endophthalmitis prophylaxis. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:456-459.].

Pythium Insidiosum Keratitis: Histopathology and Rapid Novel Diagnostic Staining Technique.

PURPOSE: To elucidate the histopathology of Pythium insidiosum keratitis and to describe a novel, simple, and rapid staining technique for identification of oomycete Pythium insidiosum and to differentiate it from fungi. METHODS: This is a laboratory investigation study of 38 nonconsecutive cases (37 ocular samples and 1 colonic biopsy); 14 microbiologically diagnosed as Pythium insidiosum keratitis and 24 as fungal keratitis. Review of clinical, demographic details, microbiological results, and identification of cases that necessitated evisceration was performed. Reevaluation of histopathology slides was done using stains such as hematoxylin-eosin, Gomori methenamine silver (GMS), periodic acid-Schiff (PAS), potassium iodide-sulfuric acid (IKI-H2SO4). Morphology, degree, and nature of inflammation and load, distribution, and staining results of Pythium insidiosum and its comparison with fungi were studied. RESULTS: Delay in zoospore formation, failure of growth, and delay in identification of Pythium were the main cause of evisceration. Corneal pythiosis showed epithelial ulceration, stromal destruction, and varying inflammation; load and distribution of Pythium were inversely proportional to inflammation. The filaments were commonly wide, with admixed narrower structures and uncommonly involved Descemet membrane. The oomycete was not discretely discerned with PAS stain and stained distinctly with GMS stain and IKI-H2SO4 stain (100% sensitive). In comparison, fungal organisms stained well with PAS and GMS stain, but not with IKI-H2SO4 stain (100% specific). CONCLUSIONS: Pythium insidiosum keratitis is perhaps not more devastating than fungal keratitis but late diagnosis, misdiagnosis, and treatment as fungal infection are major heralds. Early diagnosis may markedly improve the patient outcome. IKI-H2SO4 is a cost-effective, simple, sensitive, and specific stain for the diagnosis of oomycete Pythium.