Terpenoid-Induced Feeding Deterrence and Antennal Response of Honey Bees

Multiple interacting stressors negatively affect the survival and productivity of managed honey bee colonies. Pesticides remain a primary concern for beekeepers, as even sublethal exposures can reduce bee immunocompetence, impair navigation, and reduce social communication. Pollinator protection focuses on pesticide application guidelines; however, a more active protection strategy is needed. One possible approach is the use of feeding deterrents that can be delivered as an additive during pesticide application. The goal of this study was to validate a laboratory assay designed to rapidly screen compounds for behavioral changes related to feeding or feeding deterrence. The results of this investigation demonstrated that the synthetic Nasonov pheromone and its terpenoid constituents citral, nerol, and geraniol could alter feeding behavior in a laboratory assay. Additionally, electroantennogram assays revealed that these terpenoids elicited some response in the antennae; however, only a synthetic Nasonov pheromone, citral, and geraniol elicited responses that differed significantly from control and vehicle detections

A novel model of autologous tooth transplantation for the study of nerve recruitment

Background: Limited treatment options exist for damaged nerves and despite impressive advances in tissue engineering, scientists and clinicians have yet to fully replicate nerve development and recruitment. Innervation is a critical feature for normal organ function. While most organs are innervated prior to birth, a rare example of postnatal nerve recruitment occurs in the natural development of secondary teeth during adolescence. Many animals undergo postnatal shedding of deciduous teeth with development and eruption of secondary teeth, a process requiring recruitment of nerve and vasculature to each tooth pulp for viability. Here, the investigators created a novel model for the study of postnatal innervation by exploiting the natural phenomenon of tooth-driven nerve recruitment. Methods: The investigators theorized that developing teeth possess a special capacity to induce innervation which could be harnessed in a clinical setting for nerve regeneration, and hyptothesized that a transplant model could be created to capture this phenomenon. In this descriptive study, a rat model of autologous tooth transplantation and de novo nerve recruitment was developed by surgically transferring whole developing molars to the autologous tibia. Results: Downstream histological analysis performed 6 to 14 weeks after surgery demonstrated integration of molar into tibia in 81% of postoperative rats, with progressive pulpal expression of nerve marker ß-tubulin III suggestive of neuronal recruitment. Conclusions: These findings provide a novel model for the study of organ transplantation and support the theory that developing dental tissues may retain nerve-inductive properties postnatally

Associations of time to the operating room on outcomes in odontogenic infection

The purpose of this study was to determine if there were correlations between the length of time from hospital admission to surgical intervention and the frequency of complications in patients with odontogenic infections. While odontogenic infection is well studied in terms of interventions and outcomes, less is known about hospital utilization and resource burden of odontogenic infection with respect to timeliness to intervention. A retrospective cohort analysis was used to examine correlations between time from admission to surgical intervention and clinical outcomes. Patients included in this study were divided into three categories of length of time to the operating room: 0-12 h, 12.1-24 h, and greater than 24 h. Time of admission, time of surgical intervention, patient demographics, admission lab values, and space involvement were measured and compared to the primary outcome variables including complications of intubation attempts and type, ICU admission, length of hospitalization, number of changes in antibiotic therapy, and frequency of return to the operating room. We found that the length of time to the OR had a statistically significant association with length of hospital stay (p = 0.003) and number of changes in antibiotic therapy (p = 0.033). While overall length of hospital stay is inherently dependent on length of time to the OR, this relationship highlights the importance of timeliness to definitive intervention in order to reduce hospital burden. This study provides evidence on how to prioritize odontogenic infections in a hospital setting. We recommend treating odontogenic infection in less than 24 h from the time of admission in order to reduce costs and improve outcomes for patients

Amitraz and its metabolite modulate honey bee cardiac function and tolerance to viral infection

The health and survival of managed honey bee (Apis mellifera) colonies are affected by multiple factors, one of the most important being the interaction between viral pathogens and infestations of the ectoparasitic mite Varroa destructor. Currently, the only effective strategy available for mitigating the impact of viral infections is the chemical control of mite populations. Unfortunately, the use of in-hive acaricides comes at a price, as they can produce sublethal effects that are difficult to quantify, but may ultimately be as damaging as the mites they are used to treat. The goal of this study was to investigate the physiological and immunological effects of the formamidine acaricide amitraz and its primary metabolite in honey bees. Using flock house virus as a model for viral infection, this study found that exposure to a formamidine acaricide may have a negative impact on the ability of honey bees to tolerate viral infection. Furthermore, this work has demonstrated that amitraz and its metabolite significantly alter honey bee cardiac function, most likely through interaction with octopamine receptors. The results suggest a potential drawback to the in-hive use of amitraz and raise intriguing questions about the relationship between insect cardiac function and disease tolerance

ATP-sensitive inwardly rectifying potassium channel modulators alter cardiac function in honey bees

ATP-sensitive inwardly rectifying potassium (KATP) channels couple cellular metabolism to the membrane potential of the cell and play an important role in a variety of tissue types, including the insect dorsal vessel, making them a subject of interest not only for understanding invertebrate physiology, but also as a potential target for novel insecticides. Most of what is known about these ion channels is the result of work performed in mammalian systems, with insect studies being limited to only a few species and physiological systems. The goal of this study was to investigate the role that KATP channels play in regulating cardiac function in a model social insect, the honey bee (Apis mellifera), by examining the effects that modulators of these ion channels have on heart rate. Heart rate decreased in a concentration-dependent manner, relative to controls, with the application of the KATP channel antagonist tolbutamide and KATP channel blockers barium and magnesium, whereas heart rate increased with the application of a low concentration of the KATP channel agonist pinacidil, but decreased at higher concentrations. Furthermore, pretreatment with barium magnified the effects of tolbutamide treatment and eliminated the effects of pinacidil treatment at select concentrations. The data presented here confirm a role for KATP channels in the regulation of honey bee dorsal vessel contractions and provide insight into the underlying physiology that governs the regulation of bee cardiac function

Terpenoid-Induced Feeding Deterrence and Antennal Response of Honey Bees

Multiple interacting stressors negatively affect the survival and productivity of managed honey bee colonies. Pesticides remain a primary concern for beekeepers, as even sublethal exposures can reduce bee immunocompetence, impair navigation, and reduce social communication. Pollinator protection focuses on pesticide application guidelines; however, a more active protection strategy is needed. One possible approach is the use of feeding deterrents that can be delivered as an additive during pesticide application. The goal of this study was to validate a laboratory assay designed to rapidly screen compounds for behavioral changes related to feeding or feeding deterrence. The results of this investigation demonstrated that the synthetic Nasonov pheromone and its terpenoid constituents citral, nerol, and geraniol could alter feeding behavior in a laboratory assay. Additionally, electroantennogram assays revealed that these terpenoids elicited some response in the antennae; however, only a synthetic Nasonov pheromone, citral, and geraniol elicited responses that differed significantly from control and vehicle detections

Biological evaluation of a series of benzothiazole derivatives as mosquitocidal agents

WOS: 000475786600001Aedes aegypti is associated with the transmission of numerous human and animal diseases, such as yellow fever, dengue fever, chikungunya, and more recently Zika virus. Emerging insecticide resistance has created a need to develop new mosquitocidal agents for effective control operations. A series of benzothiazole-piperidine derivatives (1-24) were investigated for their larvicidal and adulticidal effects on Ae. aegypti. It was observed that compounds 2, 4, 6, 7, 8, 11 and 13 showed notable larvicidal activity. Furthermore, compounds 6 and 10 showed promising adulticidal activity. Based on the mosquitocidal properties of these compounds, docking studies were also carried out in the active site of the AeSCP2 enzyme to explore any insights into further in vitro enzyme studies. Docking results indicated that all these active compounds showed reasonable interactions with critical residues in the active site of this enzyme. This outcome suggested that these compounds might show their larvicidal and adulticidal effects via the inhibition of AeSCP2. According to in vitro and in silico studies, compounds 2, 4, 6, 7, 8, 10, 11 and 13 stand out as candidates for further studies.Deployed War-Fighter Protection Research Program; U.S. Department of Defense through the Armed Forces Pest Management BoardThis study was partly funded by the Deployed War-Fighter Protection Research Program via grants from the U.S. Department of Defense through the Armed Forces Pest Management Board (to JJB and to JRB). We thank Miss Jessica Louton (USDA-ARS, CMAVE, Gainesville, FL) for mosquito bioassays. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture or the U.S. Department of Defense. USDA is an equal opportunity provider and employer

Factors Influencing Dissolved Copper Concentrations in Oregon Highway Stormwater Runoff

Highway stormwater runoff represents a significant source of dissolved copper to surface waters. It is well established that even low concentrations of dissolved copper can be toxic to many aquatic organisms. In the Pacific Northwest of the United States, recent research has focused on the effects of low-level copper exposure to salmonids listed as threatened or endangered under the Endangered Species Act (ESA). In light of these recent studies, increasingly stringent guidelines for the discharge of highway stormwater runoff have been imposed as part of ESA assessments of transportation projects. Assessing factors that may impact dissolved copper concentrations in stormwater provides a practical framework for predicting when and where copper toxicity could be problematic. A stormwater sampling effort was performed to examine the influence of site locale, traffic density, storm hydrology, the “first-flush” effect, and water quality parameters on measured dissolved copper concentrations in highway stormwater runoff. In general, runoff from urban/high traffic sites and “first-flush” samples exhibited higher copper concentrations than other samples. Increased dissolved copper concentrations were highly correlated with both dissolved organic carbon (DOC) and alkalinity. However, multiple linear regression modeling suggests that only the correlation with DOC has the potential to be causative. These findings will h 18 elp inform State and Federal transportation and environmental protection agencies regarding the conditions under which elevated copper concentrations (and potential copper toxicity) are most likely to occur.Keywords: Copper, Runoff, Heavy metals, Stormwater managemen

Alkaloids with Activity against the Zika Virus Vector Aedes aegypti (L.)—Crinsarnine and Sarniensinol, Two New Crinine and Mesembrine Type Alkaloids Isolated from the South African Plant Nerine sarniensis

Two new Amaryllidaceae alkaloids, belonging to the mesembrine- and crinine-types, named crinsarnine (1) and sarniensinol (2), were isolated from the dried bulbs of Nerine sarniensis together with bowdensine (3), sarniensine (4), hippadine (5) and 1-O-acetyl-lycorine (6). Crinsarnine (1) and sarniensinol (2) were characterized using spectroscopic and chiroptical methods as (1S,2S,4aR,10bS)-2,7-dimethoxy-1,2,3,4,4a,6-hexahydro-5,11b-ethano[1,3]dioxolo-[4,5-j]phenanthridin- 1-yl acetate and (6-(3aR,4Z,6S,7aS)-6-methoxy-1-methyl-2,3,3a,6,7,7a-hexa-hydro-1H-indol-3a-yl)benzo [d][1,3]dioxol-5-yl)methanol, respectively. Furthermore, the complete spectroscopic characterization of bowdensine (3) is reported for the first time. Compounds 1–6 were evaluated against the Orlando reference strain of Aedes aegypti. None of compounds showed mortality against 1st instar Ae. aegypti larvae at the concentrations tested. In adult topical bioassays, only 1 displayed adulticidal activity with an LD50 = 2.29 ± 0.049 μg/mosquito. As regards the structure-activity relationship, the pretazettine and crinine scaffold in 2 and 4 and in 1 and 3 respectively, proved to be important for their activity, while the pyrrole[de]phenanthridine scaffold present in 5 and 6 was important for their reactivity. Among the pretazettine group compounds, opening of the B ring or the presence of a B ring lactone as well as the trans-stereochemistry of the A/B ring junction, appears to be important for activity, while in crinine-type alkaloids, the substituent at C-2 seems to play a role in their activity

Insecticide Sensitivity of Native Chloride and Sodium Channels in a Mosquito Cell Line

The aim of this study was to investigate the utility of cultured Anopheles gambiae Sua1B cells for insecticide screening applications without genetic engineering or other treatments. Sua1B cells were exposed to the known insecticidal compounds lindane and DIDS, which inhibited cell growth at micromolar concentrations. In patch clamp studies, DIDS produced partial inhibition (69%) of chloride current amplitudes, and an IC50 of 5.1 μM was determined for Sua1B cells. A sub-set of chloride currents showed no response to DIDS; however, inhibition (64%) of these currents was achieved using a low chloride saline solution, confirming their identity as chloride channels. In contrast, lindane increased chloride current amplitude (EC50 = 116 nM), which was reversed when cells were bathed in calcium-free extracellular solution. Voltage-sensitive chloride channels were also inhibited by the presence of fenvalerate, a type 2 pyrethroid, but not significantly blocked by type 1 allethrin, an effect not previously shown in insects. Although no evidence of fast inward currents typical of sodium channels was observed, studies with fenvalerate in combination with veratridine, a sodium channel activator, revealed complete inhibition of cell growth that was best fit by a two-site binding model. The high potency effect was completely inhibited in the presence of tetrodotoxin, a specific sodium channel blocker, suggesting the presence of some type of sodium channel. Thus, Sua1B cells express native insect ion channels with potential utility for insecticide screening