504 research outputs found

    Effect of non-nutritive sugars to decrease the survivorship of spotted wing drosophila, Drosophila suzukii

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    In this study, we investigated the effects of non-nutritive sugars and sugar alcohols on the survivorship of spotted wing drosophila, Drosophila suzukii, and found erythritol and erythrose as potentially insecticidal to the fly. In a dose-dependent study, erythritol and erythrose significantly reduced fly longevity, with 100% mortality with 1, 0.5, 0.1 & 0.05 M doses after feeding for 7 days. When sucrose and erythritol solutions were provided separately to flies for 7 days, there was no effect on survivorship regardless of erythritol concentrations. However, with a serial combination of sucrose and erythritol solutions, fly survivorship was significantly decreased for the same period. Also, the higher dose of erythritol regardless of the sucrose dose combined showed greater mortality. In a no-choice assay, D. suzukii ingested more erythritol than sucrose or water, indicating the fly continuously fed on erythritol for 72 h. Also under no-choice conditions, erythritol and sucrose-fed flies gained more weight than water-fed flies. However, in two-choice assays, the amount of erythritol ingested was less than sucrose or water. Total sugar and glycogen levels among erythritol and erythrose-fed flies were significantly less than mannitol, sorbitol, xylitol, and sucrose-fed flies after 48 h. This indicates that these two non-nutritive sugars can’t be used a substrate for enzymes involved in sugar metabolism. Although the metabolism of erythritol and erythrose is unknown in insects, the mortality of D. suzukii flies ingesting these sugars might be caused by two potential physiological changes. The fly is starved by feeding of non-metabolizable erythritol and erythrose, or experiences abnormally high osmotic pressure in the hemolymph with erythritol molecules diffused from the midgut. Non-nutritive sugars might be used as an insecticide alone or combined with conventional or biological insecticides to enhance efficacy. If other sugar sources are present, a palatable sugar might be mixed with erythritol to elicit feeding

    Surface Characteristics of Orthodontic Materials and Their Effects on Adhesion of Mutans streptococci

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    Objective: To test the hypothesis that there are no significant differences in the adhesion of mutans streptococci (MS) to various orthodontic materials based on their surface characteristics. Materials and Methods: Surface roughness (SR) and surface free energy (SFE) characteristics were investigated for nine different orthodontic materials (four orthodontic adhesives, three bracket raw materials, hydroxyapatite blocks, and bovine incisors) using confocal laser scanning microscopy and sessile drop method. Each material, except the bovine incisors, was incubated with whole saliva or phosphate-buffered saline for 2 hours. Adhesion assays were performed by incubating tritium-labeled MS with each material for 3 or 6 hours. Results: Orthodontic adhesives had higher SFE characteristics and lower SR than bracket materials. Orthodontic adhesives showed a higher MS retaining capacity than bracket materials, and MS adhesion to resin-modified glass ionomer and hydroxyapatite was highest. Extended incubation time increased MS adhesion, while saliva coating did not significantly influence MS adhesion. SFE, specifically its dispersive and polar components, was positively correlated with MS adhesion, irrespective of saliva coating. Conclusions: The hypothesis is rejected. This study suggests that SFE characteristics play an important role in the initial MS adhesion to orthodontic materials.This study was supported by a grant from the Korea Health 21 Project, Ministry of Health and Welfare, Republic of Korea (03-PJ1-PG1-CH09-0001)

    Overexpression and nonsynonymous mutations of UDP-glycosyltransferases are potentially associated with pyrethroid resistance in Anopheles funestus

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    UDP-glycosyltransferases (UGTs) enzymes are pivotal in insecticide resistance by transforming hydrophobic substrates into more hydrophilic forms for efficient cell elimination. This study provides the first comprehensive investigation of Anopheles funestus UGT genes, their evolution, and their association with pyrethroid resistance. We employed a genome-wide association study using pooled sequencing (GWAS-PoolSeq) and transcriptomics on pyrethroid-resistant An. funestus, along with deep-targeted sequencing of UGTs in 80 mosquitoes Africa-wide. UGT310B2 was consistently overexpressed Africa-wide and significant gene-wise F differentiation was observed between resistant and susceptible populations: UGT301C2 and UGT302A3 in Malawi, and UGT306C2 in Uganda. Additionally, nonsynonymous mutations in UGT genes were identified. Gene-wise Tajima's D density curves provide insights into population structures within populations across these countries, supporting previous observations. These findings have important implications for current An. funestus control strategies facilitating the prediction of cross-resistance to other UGT-metabolised polar insecticides, thereby guiding more effective and targeted insecticide resistance management efforts

    A Case of Disseminated and Fulminant Plasmacytomas That Developed during Bortezomib Treatment

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    Multiple myeloma is an incurable and slow growing plasma cell neoplasm. The introduction of new drugs has increased the number of treatment options. Bortezomib, the first-in-class proteasome inhibitor, has been shown to have a significant antitumor activity in the treatment of relapse/refractory patients with multiple myeloma. Additionally, plasmacytomas have shown significant response to bortezomib. In this case report, we describe a patient who developed disseminated and fulminant extramedullary plasmacytomas during combination chemotherapy treatment with bortezomib within a short period, after having shown clinical improvement

    The Possible Role of Nitric Oxide on Enteric Nerves-Mediated Relaxation of the Gastric Smooth Muscle of the Guinea Pig

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    The influence of the enteric nerves stimulation on the contractility of gastric circular muscle was studied in guinea pig stomachs. The enteric nerves were activated by electric field stimulation(EFS; 90 V, 1 rns, 32 Hz square pulses for 1 s), EFS produced initial transient contraction followed by relaxation and slow recovery. The initial contraction was sensitively blocked by treatment with atropine. The following relaxation still occurred in nonadrenergic noncholinergidNANC) state. EFSinduced relaxation was reduced by LG-nitro-L-arginine(L-NNA), a nitric oxide(NO) synthase inhibitor. The relaxation was restored from the suppressed state after the application of L-arginine(L-arg), a substrate of nitric oxide synthase. With conventional intracellular recording, slow wave and inhibitory junction potential(IJP) were recorded. L-NNA had no effect on IJP, while apamin blocked it. In conclusion, it is suggested that NO may playa major role in EFS-induced relaxation. The exact mechanism of this relaxation is unknown, but the relaxation does not result from the IJP induced by the activation of apamin-sensitive potassium channels
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