In vitro hydrodynamic performance testing of heart valve prosthesis and its clinical application / 中国胸心血管外科临床杂志

@#The heart valve prosthesis must have excellent hydrodynamic performance which is usually tested in vitro, not in vivo. This paper comprehensively introduced the principles and methods of hydrodynamic performance in vitro testing, helping clinicians to understand valve performance parameters, evaluate valve applicability, and reduce clinical risk of the valve prosthesis. In vitro testing not only serves as the "gold standard" for valve prosthesis assessment, but also provides detailed data for design and optimization of the prosthesis. ISO 5840 defines the items and methods for valve in vitro testing, which consists of three parts: (1) pulsatile flow testing, which reproduces the pulsating flow of the valve prosthesis after implantation in the human body; (2) steady flow testing, which assesses valve forward flow resistance; (3) durability testing, which evaluates the durability of the valve prosthesis and determines the expected failure   mode. In addition, the paper presented the differences between atrioventricular and aortic valve testing, the method of mitral valve testing, the differences between transcatheter and surgical valve testing, and the method of valve flow visualization.

Research progress of alternative in vitro methods to evaluate skin sensitization / 中国比较医学杂志

Skin sensitization (allergic contact dermatitis, ACD), is a serious condition caused by small reactive molecules and is characterized by a delayed-type hypersensitivity .Animal tests were usually used in the evaluation of sensitizing potential of chemical substances in the past .However , there is an increasing interest from the public for reducing and ultimately replacing animal tests .The European Union (EU) has posed a ban on animal testing of cosmetic ingredients that includes skin sensitization since 2013.Therefore, alternative in vitro tests are the main tendency in chemical substances and cosmetic sensitizing potential research in the future .In this study, different kinds of in vitro test methods that were adopted by OECD or on research (LLNA, DPRA, KeratinoSens TM, h-CLAT) were reviewed through recent years literature , comprehensive introduction and evaluation were made to obtain reliable hazard and potency information on potential skin sensitizers .

Preclinical Assessment of the Anticancer Drug Response of Plexiform Neurofibroma Tissue Using Primary Cultures

BACKGROUND AND PURPOSE: Individualized drug testing for tumors using a strategy analogous to antibiotic tests for infectious diseases would be highly desirable for personalized and individualized cancer care. METHODS: Primary cultures containing tumor and nontumor stromal cells were utilized in a novel strategy to test drug responses with respect to both efficacy and specificity. The strategy tested in this pilot study was implemented using four primary cultures derived from plexiform neurofibromas. Responses to two cytotoxic drugs (nilotinib and imatinib) were measured by following dose-dependent changes in the proportions of tumor and nontumor cells, determined by staining them with cell-type-specific antibodies. The viability of the cultured cells and the cytotoxic effect of the drugs were also measured using proliferation and cytotoxicity assays. RESULTS: The total number of cells decreased after the drug treatment, in accordance with the observed reduction in proliferation and increased cytotoxic effect upon incubation with the two anticancer drugs. The proportions of Schwann cells and fibroblasts changed dose-dependently, although the patterns of change varied between the tumor samples (from different sources) and between the two drugs. The highly variable in vitro drug responses probably reflect the large variations in the responses of tumors to therapies between individual patients in vivo. CONCLUSIONS: These preliminary results suggest that the concept of assessing in vitro drug responses using primary cultures is feasible, but demands the extensive further development of an application for preclinical drug selection and drug discovery.

Drug Resistance and in Vitro Susceptibility of Plasmodium falciparum in Thailand during 1988-2003

The aim of the present study was to investigate antimalarial drug pressure resulting from the clinical use of different antimalarials in Thailand. The phenotypic diversity of the susceptibility profiles of antimalarials, i.e., chloroquine (CQ), quinine (QN), mefloquine (MQ), and artesunate (ARS) in Plasmodium falciparum isolates collected during the period from 1988 to 2003 were studied. P. falciparum isolates from infected patients were collected from the Thai-Cambodian border area at different time periods (1988-1989, 1991-1992, and 2003), during which 3 different patterns of drug use had been implemented: MQ + sulphadoxine (S) + pyrimethamine (P), MQ alone and MQ + ARS, respectively. The in vitro drug susceptibilities were investigated using a method based on the incorporation of [3H] hypoxanthine. A total of 50 isolates were tested for susceptibilities to CQ, QN, MQ, and ARS. Of these isolates, 19, 16, and 15 were adapted during the periods 1988-1989, 1991-1993, and 2003, respectively. P. falciparum isolates collected during the 3 periods were resistant to CQ. Sensitivities to MQ declined from 1988 to 2003. In contrast, the parasite was sensitive to QN, and similar sensitivity profile patterns were observed during the 3 time periods. There was a significantly positive but weak correlation between the IC50 values of CQ and QN, as well as between the IC50 values of QN and MQ. Drug pressure has impact on sensitivity of P. falciparum to MQ. A combination therapy of MQ and ARS is being applied to reduce the parasite resistance, and also increasing the efficacy of the drug.