Assessment of consistency between peer-reviewed publications and clinical trial registrations in nursing journals.

BACKGROUND: The inconsistencies between randomized clinical trials (RCTs) registrations and peer-reviewed publications may distort trial results and threaten the validity of evidence-based medicine. Previous studies have found many inconsistencies between RCTs registrations and peer-reviewed publications, and outcome reporting bias is prevalent. AIMS: The aims of this review were to assess whether the primary outcomes and other data reported in publications and registered records in RCTs of nursing journals were consistent and whether discrepancies in the reporting of primary outcomes favored statistically significant results. Moreover, we reviewed the proportion of RCTs for prospective registration. METHODS: We systematically searched PubMed for RCTs published in the top 10 nursing journals between March 5, 2020, and March 5, 2022. Registration numbers were extracted from the publications, and registered records were identified from the registration platforms. The publications and registered records were compared to identify consistency. Inconsistencies were subdivided into discrepancies and omissions. RESULTS: A total of 70 RCTs published in seven journals were included. The inconsistencies involved sample size estimation (71.4%), random sequence generation (75.7%), allocation concealment (97.1%), blinding (82.9%), primary outcomes (60.0%) and secondary outcomes (84.3%). Among the inconsistencies in the primary outcomes, 21.4% were due to discrepancies and 38.6% resulted from omissions. Fifty-three percent (8/15) presented discrepancies in the primary outcomes that favored statistically significant results. Additionally, although only 40.0% of the studies were prospective registrations, the number of prospectively registered trials has trended upward over time. LINKING EVIDENCE TO ACTION: While not including all RCTs in the nursing field, our sample reflected a general trend: inconsistencies between publications and trial registrations were prevalent in the included nursing journals. Our research helps to provide a way to improve the transparency of research reports. Ensuring that clinical practice has access to transparent and reliable research results are essential to achieve the best possible evidence-based medicine.

Molecular cloning and function analysis of an anthocyanidin synthase gene from Ginkgo biloba, and its expression in abiotic stress responses.

Anthocyanidin synthase (ANS, leucoanthocyanidin oxygenase), a 2-oxoglutarate iron-dependent oxygenase, catalyzed the penultimate step in the biosynthesis of the anthocyanin class of flavonoids, from the colorless leucoanthocyanidins to the colored anthocyanidins. The full-length cDNA and genomic DNA sequences of ANS gene (designated as GbANS) were isolated from Ginkgo biloba for the first time. The full-length cDNA of GbANS contained a 1062-bp open reading frame (ORF) encoding a 354-amino-acid protein. The genomic DNA analysis showed that GbANS gene had three exons and two introns. The deduced GbANS protein showed high identities to other plant ANSs. The conserved amino acids (H-X-D) ligating ferrous iron and residues (R-X-S) participating in 2-oxoglutarate binding were found in GbANS at the similar positions like other ANSs. Southern blot analysis indicated that GbANS belonged to a multi-gene family. The expression analysis by real-time PCR showed that GbANS expressed in a tissue-specific manner in G. biloba. GbANS was also found to be up-regulated by all of the six tested abiotic stresses, UV-B, abscisic acid, sucrose, salicylic acid, cold and ethylene, consistent with the promoter region analysis of GbANS. The recombinant protein was successfully expressed in E. coli strain with pET28a vector. The in vitro enzyme activity assay by HPLC indicated that recombinant GbANS protein could catalyze the formation the cyanidin from leucocyanidin and conversion of dihydroquercetin to quercetin, suggesting GbANS is a bifunctional enzyme within the anthocyanidin and flavonol biosynthetic pathway.

Time course of expression of chalcone synthase gene in Ginkgo biloba.

Chalcone synthase (CHS) catalyses the first and key regulatory step of flavonoid biosynthetic pathway. A chalcone synthase gene was isolated from Ginkgo biloba leaves using the method of rapid amplification of the cDNA ends (RACE). The full-length cDNA, designated as GbCHS2, is 1,608 bp in length (GenBank accession No. DQ054841) and contains an open reading frame of 1,173 bp encoding a protein of 391 amino acids. Alignment of the predicted amino acid sequence of GbCHS2 has been shown to have high sequence similarity with GbCHS1. All the active sites and active site motifs in GbCHS1 protein were also found in GbCHS2. Correlation analysis between CHS activity and flavonoid accumulation during ginkgo leaf growth indicated that CHS might be the rate-limiting enzyme in the biosynthesis pathway of flavonoids in ginkgo leaves. Results of semi-quantitative RT-PCR analysis showed that flavonoid accumulation paralleled the transcription level of change in chs gene, suggesting chs gene as the specific key gene regulating flavonoid accumulation in ginkgo leaves.