ABSTRACT
Industrial hemp Cannabis sativa L. is an economically important crop mostly grown for its fiber, oil, and seeds. Due to its increasing applications in the pharmaceutical industry and a lack of knowledge of gene functions in cannabinoid biosynthesis pathways, developing an efficient transformation platform for the genetic engineering of industrial hemp has become necessary to enable functional genomic and industrial application studies. A critical step in the development of Agrobacterium tumefaciens-mediated transformation in the hemp genus is the establishment of optimal conditions for T-DNA gene delivery into different explants from which whole plantlets can be regenerated. As a first step in the development of a successful Agrobacterium tumefaciens-mediated transformation method for hemp gene editing, the factors influencing the successful T-DNA integration and expression (as measured by transient ß-glucuronidase (GUS) and Green Florescent Protein (GFP) expression) were investigated. In this study, the parameters for an agroinfiltration system in hemp, which applies to the stable transformation method, were optimized. In the present study, we tested different explants, such as 1- to 3-week-old leaves, cotyledons, hypocotyls, root segments, nodal parts, and 2- to 3-week-old leaf-derived calli. We observed that the 3-week-old leaves were the best explant for transient gene expression. Fully expanded 2- to 3-week-old leaf explants, in combination with 30 min of immersion time, 60 µM silver nitrate, 0.5 µM calcium chloride, 150 µM natural phenolic compound acetosyringone, and a bacterial density of OD600nm = 0.4 resulted in the highest GUS and GFP expression. The improved method of genetic transformation established in the present study will be useful for the introduction of foreign genes of interest, using the latest technologies such as genome editing, and studying gene functions that regulate secondary metabolites in hemp.
ABSTRACT
BACKGROUND: Dosing of four factor prothrombin complex concentrate (4PCC) for warfarin reversal remains controversial. Recently, the American College of Cardiology (ACC) recommended a low-dose PCC regimen as an option for warfarin reversal in acute major bleeding. We performed a retrospective study evaluating if a modified version of the ACC guideline recommendations was effective for warfarin reversal in acute major bleeds when compared to traditional variable dosing. METHODS: This was a retrospective cohort study of patients who received 4PCC for warfarin reversal in a 12 month period. We included patients that were ≥18 years of age, received 4PCC for warfarin reversal, and had an initial International Normalized Ratio (INR) of >2. Our primary outcome was the number of patients who had a post-4PCC infusion INR of <1.6. RESULTS: A total of 60 patients were included in the final analysis with 30 patients stratified to the traditional dosing and low-dose groups, respectively. Patient demographics were similar between both groups. We found no difference in the number of patients who had a post-4PCC infusion INR <1.6 between the traditional dosing and low dosing group (90.0% vs. 86.7%; p = 0.68). Additionally, we found no difference between post-infusion median INRs in each group (1.35 vs. 1.30; p = 0.16). Approximately 1000 units per patient were spared when utilizing the low-dose regimen. CONCLUSION: A modified version of the ACC's low-dose 4PCC option for warfarin reversal achieves similar outcomes for lowering INR values compared to traditional variable dosing regimens.
