Profile of malignant hyperthermia susceptibility reports confirmed with muscular contracture test in Brazil
REVISTA BRASILEIRA DE ANESTESIOLOGIA
Authors: Almeida da Silva, Helga Cristina; Ferreira, Gisele; Rodrigues, Gislene; dos Santos, Joilson Moura; Andrade, Pamela Vieira; Hortense, Alexandre; Perez, Marcelo Vaz; Gomes do Amaral, Jose Luiz
Abstract
Background and objectives: Malignant hyperthermia is an autosomal dominant hypermetabolic pharmacogenetic syndrome, with a mortality rate of 10%-20%, which is triggered by the use of halogenated inhaled anesthetics or muscle relaxant 10%-20% succinylcholine. The gold standard for suspected susceptibility to malignant hyperthermia is the in vitro muscle contracture test in response to halothane and caffeine. The determination of susceptibility in suspected families allows the planning of safe anesthesia without triggering agents for patients with known susceptibility to malignant hyperthermia by positive in vitro muscle contracture test. Moreover, the patient whose suspicion of malignant hyperthermia was excluded by the in vitro negative muscle contracture test may undergo standard anesthesia. Susceptibility to malignant hyperthermia has a variable manifestation ranging from an asymptomatic subject presenting a crisis of malignant hyperthermia during anesthesia with triggering agents to a patient with atrophy and muscle weakness due to central core myopathy. The aim of this study is to analyze the profile of reports of susceptibility to malignant hyperthermia confirmed with in vitro muscle contracture test. Method: Analysis of the medical records of patients with personal/family suspicion of malignant hyperthermia investigated with in vitro muscle contracture test, after given written informed consent, between 1997 and 2010. Results: Of the 50 events that motivated the suspicion of malignant hyperthermia and family investigation (sample aged 27 +/- 18 years, 52% men, 76% white), 64% were investigated for an anesthetic malignant hyperthermia crisis, with mortality rate of 25%. The most common signs of a malignant hyperthermia crisis were hyperthermia, tachycardia, and muscle stiffness. Susceptibility to malignant hyperthermia was confirmed in 79.4% of the 92 relatives investigated with the in vitro muscle contracture test. Conclusion: The crises of malignant hyperthermia resembled those described in other countries, but with frequency lower than that estimated in the country. (C) 2018 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda.
A novel mutation panel for predicting etoposide resistance in small-cell lung cancer
DRUG DESIGN DEVELOPMENT AND THERAPY
Authors: Qiu, Zhengang; Lin, Anqi; Li, Kun; Lin, Weiyin; Wang, Qiongyao; Wei, Ting; Zhu, Weiliang; Luo, Peng; Zhang, Jian
Abstract
Purpose: Platinum-based chemotherapy, consisting of etoposide and cisplatin (EP), has been the cornerstone of therapy for extensive-stage small-cell lung cancer (ES-SCLC) for decades. Despite the marked initial sensitivity of SCLC to chemotherapy, EP regimens cannot avoid the emergence of drug resistance in clinical practice. With the rise of new chemotherapy regimens in recent years and the primary resistance or insensitivity of ES-SCLC to EP regimens, it is desirable to be able to identify patients with resistant or insensitive ES-SCLC. Methods: The sequencing and drug sensitivity data of SCLC cell lines were provided by The Genomics of Drug Sensitivity in Cancer Project (GDSC). The data regarding sensitivity to etoposide of 54 SCLC cell lines were analyzed, and etoposide-sensitive cell lines and etoposide-resistant cell lines were differentiated according to the IC50 values defined by the GDSC. ROC curve analysis was performed on all mutations and combinations of mutations to select the optimal panel to predict resistance to etoposide. Results: ROC analysis of etoposide resistance revealed that the most significant single gene mutation indicating resistance to etoposide was CSMD3, and the accuracy of predicting resistance to etoposide proved to be the highest when there was any mutation in CSMD3/ PCLO/RYR1/EPB41L3, area under the curve =0.804 (95% confidence interval: 0.679-0.930, P<0.001). Conclusion: This study found that a panel with four genes (CSMD3, EPB41L3, PCLO, and RYR1) can accurately predict sensitivity to etoposide. These findings provide new insights into the overall treatment for patients with ES-SCLC that is resistant or insensitive to etoposide.