Influence of Maximal Strength on In-Water and Dry-Land Performance in Young Water Polo Players.

Keiner, M, Rähse, H, Wirth, K, Hartmann, H, Fries, K, and Haff, GG. Influence of maximal strength on in-water and dry-land performance in young water polo players. J Strength Cond Res 34(7): 1999-2005, 2020-Water polo is a multifaceted sport that is characterized by explosive actions, including sprint swimming, jumping, throwing, and struggling against opponents. Based on these factors, maximal and speed strength may be important characteristics to develop in-water polo players. However, more research is needed to further understand the relationship between various strength characteristics and water polo performance. Therefore, the primary purpose of this study was to examine the relationships between strength, speed strength, and markers of water polo performance in youth water polo players. Sixty-one male youth water polo players (10-14 years, 11.9 ± 1.3 years) had their 1-repetition maximum (1RM) bench press and squat, dry-land speed-strength performance (squat jump [SJ], countermovement jump [CMJ], and medicine ball throw), in-water performance (sprint swim and water jump), and anthropometric measurements assessed. Fifty to 60% of the variance in sprint performance was explained by the 1RM bench press and arm span. The influence of the bench press 1RM was more than twice that of the anthropometric factors. Maximum strength in the squat and speed-strength (jump height in SJ, CMJ) variables explained 18-25% variance in the eggbeater kick (a leg strike technique to stay above and jump out of water), and the bench press 1RM explained the 42% of the variance in loaded throws without the influence of anthropometric factors. This study suggests that upper- and lower-body maximal strength parameters are important predictors of the performance capacity of water polo players.

Phage display-based on-slide selection of tumor-specific antibodies on formalin-fixed paraffin-embedded human tissue biopsies.

Phage display is an effective method for the generation of target-specific human antibodies. Standard phage display panning use purified proteins, antigen-transfected cells or tumor cell lines as target structure to generate specific antibodies. However, recombinant proteins can be difficult to express and purify in their native conformation and suitable cell lines are not always available. Additionally the antigen expression profile may change during cultivation and thus differ from the malignant cells in patient. Here we describe a method for the selection of specific antibodies from phage display libraries by panning against formalin-fixed paraffin-embedded (FFPE) tissue biopsies immobilized on glass slides, using small cell lung cancer (SCLC) as a case study. The human Tomlinson single-chain variable fragment (scFv) phage libraries I and J were panned against SCLC FFPE tissue slides for positive selection and healthy lung tissue for subtraction. The specificity of the selected scFv antibodies was confirmed in vitro by ELISA on immobilized SCLC cell membranes, by flow cytometry using the SCLC cell lines NCI-H69, NCI-H82 and DMS 273, and ex vivo against tissue microarrays containing 35 different SCLC samples and 20 types of normal organs. We monitored the internalization of three selected scFv antibodies and fused them with Pseudomonas exotoxin A (ETA') to produce immunotoxins whose cytotoxicity was confirmed by cell viability and apoptosis assays on different SCLC cell lines, achieving IC50 values of up to 23nM. The selection of SCLC-specific scFv antibodies by panning against FFPE tissue slides circumvents the challenges of using purified antigens or cell lines for antibody selection.