Integrated approaches for Solenopsis invicta (Hymenoptera: Formicidae) management: insights from laboratory studies with entomopathogenic nematodes and insecticides.

BACKGROUND: In agricultural pest management, especially in combatting the invasive red imported fire ant (RIFA, Solenopsis invicta), significant challenges emerge as a consequence of the constraints of solely depending on chemical insecticides or entomopathogenic nematodes (EPNs). The utilization of chemical insecticides carries environmental and ecological hazards, whereas EPNs, when applied independently, might not offer the immediate effectiveness necessary for adequate RIFA suppression. Acknowledging these hurdles, our study investigates a synergistic method that integrates EPNs with chemical insecticides, aiming to fulfill the urgent demand for more efficient and environmentally friendly pest control solutions. RESULTS: Our evaluation focused on the interaction between the highly pathogenic Steinernema riobrave 7-12 EPN strain and prevalent insecticides, specifically beta-cypermethrin and a mixture of bifenthrin and clothianidin, applied at highly diluted recommended concentrations. The findings revealed a notable increase in RIFA mortality rates when EPNs and these insecticides were used together, outperforming the results achieved with each method individually. Remarkably, this enhanced efficacy was especially evident at lower concentrations of the bifenthrin-clothianidin mixture, indicating a valuable approach to minimizing reliance on chemical insecticides in agriculture. Furthermore, the high survival rates of EPNs alongside the tested insecticides indicate their compatibility and potential for sustained use in integrated pest management programs. CONCLUSION: Our research underscores the effectiveness of merging EPNs with chemical insecticides as a powerful and sustainable strategy for RIFA management. This combined approach not only meets the immediate challenges of pest control in agricultural settings, but also supports wider environmental objectives by reducing the dependency on chemical insecticides. © 2024 Society of Chemical Industry.

Mesenchymal Stem Cell Delivery via Topographically Tenoinductive Collagen Biotextile Enhances Regeneration of Segmental Tendon Defects.

BACKGROUND: Successful management of massive rotator cuff (RC) tendon tears represents a treatment challenge because of the limited intrinsic healing capacity of native tendons and the risk of repair failure. Biologic augmentation of massive RC tears utilizing scaffolds-capable of regenerating bulk tendon tissue to achieve a mechanically functional repair-represents an area of increasing clinical interest. PURPOSE: To investigate the histological and biomechanical outcomes after the use of a novel biologic scaffold fabricated from woven electrochemically aligned collagen (ELAC) threads as a suture-holding, fully load-bearing, defect-bridging scaffold with or without mesenchymal stem cells (MSCs) compared with direct repair in the treatment of critically sized RC defects using a rabbit model. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 34 New Zealand White rabbits underwent iatrogenic creation of a critically sized defect (6 mm) in the infraspinatus tendon of 1 shoulder, with the contralateral shoulder utilized as an intact control. Specimens were divided into 4 groups: (1) gap-negative control without repair; (2) direct repair of the infraspinatus tendon-operative control; (3) tendon repair using ELAC; and (4) tendon repair using ELAC + MSCs. Repair outcomes were assessed at 6 months using micro-computed tomography, biomechanical testing, histology, and immunohistochemistry. RESULTS: Specimens treated with ELAC demonstrated significantly less tendon retraction when compared with the direct repair group specimens (P = .014). ELAC + MSCs possessed comparable biomechanical strength (178 ± 50 N) to intact control shoulders (199 ± 35 N) (P = .554). Histological analyses demonstrated abundant, well-aligned de novo collagen around ELAC threads in both the ELAC and the ELAC + MSC shoulders, with ELAC + MSC specimens demonstrating increased ELAC resorption (7% vs 37%, respectively; P = .002). The presence of extracellular matrix components, collagen type I, and tenomodulin, indicating tendon-like tissue formation, was appreciated in both the ELAC and the ELAC + MSC groups. CONCLUSION: The application of MSCs to ELAC scaffolds improved biomechanical and histological outcomes when compared with direct repair for the treatment of critically sized defects of the RC in a rabbit model. CLINICAL RELEVANCE: This study demonstrates the feasibility of repairing segmental tendon defects with a load-bearing, collagen biotextile in an animal model, showing the potential applicability of RC repair supplementation using allogeneic stem cells.

Methylation of CDKN2B CpG islands is associated with upregulated telomerase activity in children with acute lymphoblastic leukemia.

The aim of the present study was to investigate the association between methylation of cyclin-dependent kinase inhibitor 2B (CDKN2B) CpG islands and telomerase activity in children with acute lymphoblastic leukemia (ALL). A total of 72 children with ALL and 12 children with immune thrombocytopenia (ITP) were subjected to bone marrow aspiration and methylation-specific polymerase chain reaction analysis, and modified telomeric repeat amplification protocol assay analyses, to evaluate CDKN2B methylation and telomerase activity, respectively. The results of the present study demonstrated that, of these 72 children with ALL, 31 exhibited CDKN2B methylation at diagnosis (43.1%), whereas 41 exhibited no CDKN2B methylation (36.9%). However, no CDKN2B methylation was detected in the ITP controls. Furthermore, the mean level of telomerase activity was 39.52±39.33 total product generated (TPG) units in children with ALL, which was significantly increased compared with 2.49±2.27 TPG units in the ITP controls (P=0.002). The mean levels of telomerase were 49.09±44.43 and 29.99±32.43 TPG units in children with ALL with and without CDKN2B methylation, respectively (P=0.041), therefore children with ALL exhibited significantly increased levels of telomerase. The increased telomerase activity was significantly associated with increased risk of childhood ALL (P=0.023). A total of 22/31 children with ALL with methylated CDKN2B (71.0%) and 17/41 children with ALL with unmethylated CDKN2B (41.46%) exhibited increased telomerase activity (>15 TPG units). The results of the present study suggest that hypermethylation of CDKN2B CpG islands and hyperactivity of telomerase are common events in childhood ALL, and hypermethylation of CDKN2B CpG islands was significantly associated with upregulated telomerase activity (P=0.013).