Results of Randomized Controlled Trials of Platelet-Rich Plasma in Lower-Extremity Tendinopathy Are Not Influenced by Industry Sponsorship.

PURPOSE: To determine whether industry affiliation influences the results of randomized controlled trials (RCTs) studying the use of platelet-rich plasma (PRP) for the treatment of patellar or Achilles tendinopathy. METHODS: The PubMed, Scopus, Cochrane, and MEDLINE databases were searched in July 2023 for RCTs investigating PRP for the treatment of patellar or Achilles tendinopathy published between 2009 and July 2023. Industry affiliation was determined by analyzing each study's funding or conflict-of-interest section. Author disclosures were searched in the American Academy of Orthopaedic Surgeons disclosure database and the Centers for Medicare & Medicaid Services open payments database. An industry-affiliated (IA) designation was given if an author had a relevant disclosure or if the company that funded the study manufactured PRP. Otherwise, a non-industry-affiliated (NIA) designation was given. Fisher exact analysis was used to determine whether PRP had a favorable effect, no significant effect, or an unfavorable effect on outcome. RESULTS: Analysis was performed on 22 studies (10 IA and 12 NIA), with 17 studies (77.3%) reporting a conflict of interest or funding for the research, 4 (18.2%) reporting no conflict of interest, and 1 (4.5%) with no reporting. Of the 22 included studies, 8 (36.4%) reported favorable outcomes regarding PRP use and 14 (63.6%) reported no significant effect. Favorable outcomes were found in 4 of the 10 IA studies (40.0%), whereas no significant effect was reported in 6 (60.0%). The 12 NIA studies included 4 (33.3%) with favorable results and 8 (66.7%) with no significant effect. The comparison between industry affiliation and results reported was not statistically significant (P > .999). CONCLUSIONS: The results of RCTs evaluating the use of PRP in lower-extremity tendinopathy were not influenced by industry sponsorship. CLINICAL RELEVANCE: Most biomedical research is funded through industry sponsorship. Although this relation is necessary as technologies are developed, it is important to scrutinize studies for evidence of industry bias to understand how this bias may be affecting study results published in the literature.

Crystallization of DIR1, a LTP2-like resistance signalling protein from Arabidopsis thaliana.

DIR1, a putative LTP2 protein from Arabidopsis thaliana implicated in systemic acquired resistance in planta, has been crystallized in space group P2(1)2(1)2(1) with one molecule per asymmetric unit. The crystals diffract to a resolution of 1.6 angstroms.

A putative lipid transfer protein involved in systemic resistance signalling in Arabidopsis.

Localized attack by a necrotizing pathogen induces systemic acquired resistance (SAR) to subsequent attack by a broad range of normally virulent pathogens. Salicylic acid accumulation is required for activation of local defenses, such as pathogenesis-related protein accumulation, at the initial site of attack, and for subsequent expression of SAR upon secondary, distant challenge. Although salicylic acid moves through the plant, it is apparently not an essential mobile signal. We screened Agrobacterium tumefaciens transfer DNA (tDNA) tagged lines of Arabidopsis thaliana for mutants specifically compromized in SAR. Here we show that Defective in induced resistance 1-1 (dir1-1) exhibits wild-type local resistance to avirulent and virulent Pseudomonas syringae, but that pathogenesis-related gene expression is abolished in uninoculated distant leaves and dir1-1 fails to develop SAR to virulent Pseudomonas or Peronospora parasitica. Petiole exudate experiments indicate that dir1-1 is defective in the production or transmission from the inoculated leaf of an essential mobile signal. DIR1 encodes a putative apoplastic lipid transfer protein and we propose that DIR1 interacts with a lipid-derived molecule to promote long distance signalling.