Flower Mimics Roll Out Multicolored Carpets to Lure and Kill the House Fly.

Flowers and their spatial clustering are important parameters that mediate the foraging behavior and visitation rate of pollinating insects. Visual stimuli are crucial for triggering behavioral changes in the house fly, Musca domestica, which regularly visits plants for feeding and reproduction. The success of bait technology, which is the principal means of combatting flies, is adversely affected by reduced attractiveness and ineffective application techniques. Despite evidence that house flies have color vision capacity, respond to flowers, and exhibit color and pattern preference, the potential of artificial flowers as attractive factors has not been explored. The present study was performed to investigate whether artificial floral designs can lure and kill house flies. Starved wild house flies were presented with equal opportunities to acquire sugar meals, to which boric acid had been added as a toxin, from one flower arrangement (blue-dominated design, BDD; yellow-dominated design, YDD; or pink-dominated design, PDD), and a non-toxic white design (WDD). We also allowed house flies to forage within an enclosure containing two non-toxic floral designs (WDDs). The differences in mortality between the two environments with and without toxicant were examined. The survival rate of Musca domestica was extremely high when WDDs containing non-toxic sugar sources were the only feeding sites available. When given an option to forage in an environment containing a BDD and a WDD, house flies showed a high mortality rate (76%) compared to their counterparts maintained in the WDD environment (2%). When kept in an enclosure containing one YDD and a WDD, flies showed a mortality rate of 88%; however, no mortality occurred among flies confined to a compound with a WDD pair. When provided an even chance of foraging in an enclosure containing a mixed pair of floral arrangements (PDD and WDD) and another with two WDDs, flies showed a higher mortality rate (78%) in the first environment. However, the maximum survival rate (100%) was seen in the WDD environment. Exposure to YDD tended to result in a greater mortality rate than with the two other floral designs. Mortality gradually increased with time among flies exposed to tested artificial floral designs. The results presented here clearly indicated that artificial flower arrangements with a toxic sugar reward were strikingly attractive for house flies when their preferred color (white) was present. These observations offer novel possibilities for future development of flower mimic-based house fly control.

Characterization and pharmacokinetic evaluation of microcomposite particles of alpha lipoic acid/hydrogenated colza oil obtained in supercritical carbon dioxide.

The work reported here is an extension of our previous findings in which supercritical composite particles (SCP) of alpha lipoic acid (ALA) masked with hydrogenated colza oil (HCO) named as ALA/HCO/SCP were obtained by the modified particles from gas-saturated solutions (PGSS) process in supercritical carbon dioxide in order to obscure the unpleasant taste and odor of ALA. The masking effect on ALA/HCO/SCP was compared with the widely used mechano-chemically masked formulation of ALA and HCO named as MC-50F. In the present study, ALA/HCO/SCP particles were found to have a significant improvement in regard to bitterness, numbness, and smell compared to ALA bulk powders suggesting they were well coated. The pharmacokinetic parameters for ALA/HCO/SCP and ALA bulk powder gave similar values but were significantly different from those of MC-50F. The amount of ALA absorbed into the body, in the administered ALA/HCO/SCP, was comparable to that absorbed by ALA bulk powder, whereas about half portion of ALA of the MC-50F was not absorbed, because the ALA/HCO/SCP particles were small enough and the particles of MC-50F were relatively large and had smaller specific surface area. Therefore, this study suggested a newly masked candidate may offer functional particles with maintained efficacy.

The electronic song "Scary Monsters and Nice Sprites" reduces host attack and mating success in the dengue vector Aedes aegypti.

Sound and its reception are crucial for reproduction, survival, and population maintenance of many animals. In insects, low-frequency vibrations facilitate sexual interactions, whereas noise disrupts the perception of signals from conspecifics and hosts. Despite evidence that mosquitoes respond to sound frequencies beyond fundamental ranges, including songs, and that males and females need to struggle to harmonize their flight tones, the behavioral impacts of music as control targets remain unexplored. In this study, we examined the effects of electronic music (Scary Monsters and Nice Sprites by Skrillex) on foraging, host attack, and sexual activities of the dengue vector Aedes aegypti. Adults were presented with two sound environments (music-off or music-on). Discrepancies in visitation, blood feeding, and copulation patterns were compared between environments with and without music. Ae. aegypti females maintained in the music-off environment initiated host visits earlier than those in the music-on environment. They visited the host significantly less often in the music-on than the music-off condition. Females exposed to music attacked hosts much later than their non-exposed peers. The occurrence of blood feeding activity was lower when music was being played. Adults exposed to music copulated far less often than their counterparts kept in an environment where there was no music. In addition to providing insight into the auditory sensitivity of Ae. aegypti to sound, our results indicated the vulnerability of its key vectorial capacity traits to electronic music. The observation that such music can delay host attack, reduce blood feeding, and disrupt mating provides new avenues for the development of music-based personal protective and control measures against Aedes-borne diseases.

Δ9-Tetrahydrocannabinol elicited 22-kHz ultrasonic vocalization changes after air puff stimulus through CB1 receptor in adult rats.

Δ9-Tetrahydrocannabinol (THC) is known to have various pharmacological effects mediated through activation of cannabinoid CB1 and CB2 receptors in rodents. In adult rats, 22- and 50-kHz ultrasonic vocalizations (USVs) serve as an effective communication system and as indicators of negative and positive states, respectively. The present study was performed to determine whether THC affects USVs in adult rats, and to determine the roles of cannabinoid receptors in these effects. THC (1, 3 mg/kg) was administered intraperitoneally to adult male Wistar rats 60 min before measurement of USVs. The CB1 antagonist, SR141716 (3, 6 mg/kg), or CB2 antagonist, AM630 (1, 10 mg/kg), was administered intraperitoneally 10 min before THC. USVs were measured during a 5-minute period without air puff stimulus or with air puff stimulus. THC did not affect 22- or 50-kHz USVs without air puff stimulus. On the other hand, THC significantly increased the number of 22-kHz USVs, but not 50-kHz USVs, after air puff stimulus. Moreover, SR141716 at 6 mg/kg, but not AM630 at either dose, inhibited the increase in number of 22-kHz USVs induced by THC after air puff stimulus. These results suggest that THC induced changes in sensitivity to aversive air puff stimuli through CB1 receptors, and as a result increased emission of 22-kHz USVs in rats.

Lactobacillus plantarum induces genomic DNA-dependent and TLR9-mediated elafin secretion from Caco-2 cells.

BACKGROUND: Lactobacilli show anti-inflammatory effects in the human intestine, and their genomic DNA was identified as one of the anti-inflammatory components. Increased levels of the natural protease inhibitor elafin in the intestine plays an important role in protection against intestinal inflammation. However, there have been no previous reports regarding whether lactobacilli increase elafin levels. OBJECTIVE: This study was performed to investigate whether Lactobacillus plantarum induces elafin secretion from the human epithelial colorectal adenocarcinoma cell line, Caco-2. Moreover, we examined the roles of bacterial genomic DNA and toll-like receptor 9 (TLR9), a specific receptor of bacterial DNA, in this effect. METHODS: Elafin secretion from Caco-2 cells by live and heat-killed L. plantarum was measured. The analysis was also performed using DNase-treated L. plantarum and genomic DNA extracted from L. plantarum. We examined the role of TLR9 in elafin secretion by L. plantarum and its genomic DNA by suppressing TLR9 expression using RNAi in Caco-2 cells. RESULTS: Heat-killed L. plantarum time- and dose-dependently increased elafin secretion, whereas live L. plantarum had no such effect. The elafin secretion by heat-killed L. plantarum was partially abolished by DNase treatment of the bacterium. In addition, L. plantarum genomic DNA also increased elafin secretion. Furthermore, suppression of TLR9 expression partially or completely abolished elafin secretion by heat-killed L. plantarum and its genomic DNA. CONCLUSION: Our results indicated that heat-killed L. plantarum induced genomic DNA-dependent and TLR9-mediated elafin secretion. The anti-inflammatory effects of lactobacilli may be mediated by increases in the levels of elafin in the intestine.

Courtship activity, copulation & insemination success in a mosquito vector fed a herbal aphrodisiac: Implications for sterile insect technology.

BACKGROUND & OBJECTIVES: In sterile insect technology (SIT), mating competitiveness is a pre-condition for the reduction of target pest populations and a crucial parameter for judging efficacy. Still, current SIT trials are being hindered by decreased effectiveness due to reduced sexual performance of released males. Here, we explored the possible role of a herbal aphrodisiac in boosting the mating activity of Aedes aegypti. METHODS: Males were fed one of two diets in this study: experimental extract of Eurycoma longifolia (MSAs) and sugar only (MSOs). Differences in life span, courtship latency, copulation activity and mating success were examined between the two groups. RESULTS: No deaths occurred among MSA and MSO males. Life span of MSOs was similar to that of MSAs. The courtship latency of MSAs was shorter than that of MSOs (P<0.01). MSAs had greater copulation success than MSOs (P<0.001). In all female treatments, MSAs mated more than MSOs, but the differences in rate were significant only in the highest female density (P<0.05). In MSAs, mating success varied significantly with female density (P<0.01), with the 20-female group (P<0.01) having the lowest rate. Single MSA had better mating success at the two lowest female densities. In MSOs, there were no significant differences in mating success rate between the different female densities. INTERPRETATION & CONCLUSIONS: Our results suggested that the herbal aphrodisiac, E. longifolia, stimulated the sexual activity of Ae. aegypti and may be useful for improving the mating competitiveness of sterile males, thus improving SIT programmes.

Exposure of a diurnal mosquito vector to floral mimics: Foraging responses, feeding patterns, and significance for sugar bait technology.

Food location by mosquitoes is mediated by resource-derived olfactory and visual signals. Smell sensation is intermittent and dependent on the environment, whereas visual signals are continual and precede olfactory cues. Success of mosquito bait technology, where olfactory cues are used for attraction, is being impeded by reduced attractiveness. Despite proof that mosquitoes respond to colored objects, including those mimicking floral shape, and that they can discriminate among flowers, the impacts of artificial flowers on foraging remain unexplored. Using artificial flowers with sugar rewards, we examined the foraging responses of Aedes aegypti to various colors in equal choice bioassays. Starved adults were exposed to single flowers with petals of a given color (Single Blue Flowers [SBFs]; Single Red Flowers [SRFs]; Single Yellow Flowers [SYFs]; Single Pink Flowers [SPIFs]; and Single Purple Flowers [SPFs]) and two others with white petals (SWFs). Discrepancies in response time, visitation, feeding, and resting of both sexes were compared between colored flowers and SWFs. Ae. aegypti exhibited shorter response times to colored flowers compared to SWFs, but this behavior was mostly seen for SBFs or SYFs in females, and SRFs, SYFs, SPIFs, or SPFs in males. When provided an option to land on colored flowers and SWFs, female visitation occurred at high rates on SBFs, SRFs, SYFs, SPIFs, and SPFs; for males, this preference for colored flowers was seen to a lesser degree on SBF and SPIFs. Both sexes exhibited preference for colored flowers as sugar sources, but with different patterns: SPIFs, SRFs, SYFs, and SPFs for females; SYFs, SPFs, SPIFs and SRFs for males. Females preferentially rested on colored flowers when in competition with SWFs, but this preference was more pronounced for SPFs, SRFs, and SBFs. Males exhibited an increased preference for SRFs, SPFs, and SYFs as resting sites. Our results indicated the attraction of Ae. aegypti to rewarding artificial flowers, in some cases in ways similar to live flowering plants. The discovery that both male and female Ae. aegypti can feed on nectar mimics held by artificial flowers opens new avenues for improving sugar bait technology and for developing new attract-and-kill devices.

Occurrence of sweet refuse at disposal sites: rainwater retention capacity and potential breeding opportunities for Aedes aegypti.

Nectar is the staple diet of adult mosquitoes in the wild, but its availability is inconsistent and can be affected by rainfall. In urban centers, Aedes vectors commonly use man-made containers as their major habitat; however, they can colonize any items replenished by rainfall. Garbage output has increased significantly in recent years, at a time when collection frequency is reducing. Such garbage usually includes organic components, some of which are sweet and can be fed upon by other animals or become can containers for rainwater. Despite evidence that Aedes larvae can thrive in containers comprised of organic waste material, which can be produced by rodents gnawing on fruits or vegetables, and that adults can survive on sweet waste fluids, the capacity of organic waste materials to accumulate rainwater and act as egg deposition sites has not been examined. It is also unknown for how long sweet extracts can sustain the life of adult vectors. Here, we investigated the abundance of sweet leftovers at garbage sites and the rainwater retention capacity of some organic materials through a field survey and laboratory bioassays. We also examined whether sweet waste fluids impact egg hatching success and longevity of Aedes aegypti. The results of this study indicated that sweet products with leftovers are highly prevalent in garbage. When exposed to rain, food items (BAFrc, banana fruit resembling container; and BSPrc, boiled sweet potato resembling container) and the packaging of sweet foods (SMIc, sweetened condensed milk can) retained water. When provided an opportunity to oviposit in cups containing BAF extract (BAFex), BSP extract (BSPex), and SMI extract (SMIex), eggs were deposited in all media. Egg maturation in the BAFex environment resulted in similar larval eclosion success to that resulting from embryo development in a water milieu. Adults maintained on sweet waste extracts had long lifespans, although shorter than that of their sugar solution (SUS)-fed counterparts. Taken together, these results indicated that sweet waste materials are useful to dengue mosquitoes, acting both as oviposition sites and energy sources.

Identification and characterization of a brilliant yellow pigment produced by Bordetella pertussis.

Culture supernatants of Bordetella pertussis are a brilliant yellow; however, the structure and biological role of the responsible pigment have not been investigated. In this study, a brilliant yellow-colored fraction was extracted from culture supernatants of B. pertussis and analyzed by HPLC. UV-visible spectral analysis and mass spectrometry identified the brilliant yellow pigment as riboflavin. Riboflavin production was high in lag and early log phases and riboflavin was found to enhance growth of B. pertussis in low-density cultures. Riboflavin production is not regulated by the BvgAS system. In addition, it was found that other Bordetella species, such as B. parapertussis, B. holmesii and B. bronchiseptica, also release riboflavin into their culture supernatants. This is the first report that B. pertussis secrets riboflavin to the extracellular space and that riboflavin may promote its growth. The mechanism may be associated with pathogenesis of B. pertussis.

Presence of a predator image in potential breeding sites and oviposition responses of a dengue vector.

In dengue vector control, attempts to minimize or replace the use of pesticides have mostly involved use of predators, but success has been severely impeded by difficulties associated with financial and environmental costs, predator mass production, and persistence in target habitats. Visual deterrents have been used successfully to control animal pests, in some cases in an effort to replace pesticide use. Despite evidence that visual signals are crucial in site choice for egg deposition by dengue vectors, and that female mosquitoes respond to artificial predation, the role of predator intimidation as it affects the oviposition behavior of dengue vectors remains largely unexplored. Here, we examined the oviposition responses of Aedes aegypti exposed to various mosquito predator pictures. Gravid females were presented with equal opportunities to oviposit in two cups with predator images [Toxorhynchites splendens-TXI, Goldfish (Carassius auratus)-small (SFI) and large (LFI) and Tx. splendens+Goldfish-TXFI] and two others without pictures. Differences in egg deposition were examined between sites with and without these images. When given a chance to oviposit in cups with and without TXI, Ae. aegypti females were similarly attracted to both sites. When provided an opportunity to oviposit in cups displaying pictures of fish (SFI or LFI) and blank cups, egg deposition rates were much lower in the fish picture sites. Females showed a preference for blank cups over TXFI for egg deposition. They also equally avoided cups with pictures of fish, regardless of the size of the picture. Our results indicate that the presence of images of goldfish and their association with Tx. larvae significantly reduced egg deposition by Ae. aegypti, and this was not the case with the predatory larvae alone. The observations that the images of natural predators can repel gravid females of a dengue vector provide novel possibilities to develop effective and inexpensive alternative tools to harmful insecticides.

Anti-oviposition activities of used sock media against a dengue vector: prospects of eco-friendly control and solutions to pollution.

Yearly, huge amounts of sock refuse are discarded into the environment. Socks contain many molecules, and worn ones, which are rich in smell-causing bacteria, have a strong influence on animals' behaviors. But the impacts of sock odor on the oviposition behavior of dengue vectors are unknown. We assessed whether Aedes albopictus changes its oviposition activity in response to the presence of used socks extract (USEx) in potential breeding grounds, using choice and no-choice bioassays (NCB). When furnished even chances to oviposit in two sites holding USEx and two others containing water (control), Ae. albopictus deposited significantly less eggs in USEx than in water sites. A similar pattern of oviposition preference was also observed when there were more oviposition options in water. When there were greater oviposition opportunities in USEx sites, Ae. albopictus oviposited preferentially in water. Females laid significantly more eggs during the NCB involving water than USEx. Also, significantly more mature eggs were retained by females in the NCB with USEx than in that with water. These observations strongly suggest the presence of molecules with either repellent or deterrent activities against Ae. albopictus females and provide an impetus to advocate the integration of used socks in dengue control programs. Such applications could be a realistic end-of-life recourse to reroute this waste from landfills.

Involvement of Charcot-Marie-Tooth disease gene mitofusin 2 expression in paclitaxel-induced mechanical allodynia in rats.

Paclitaxel induces peripheral neuropathy, which is dose-limiting and results in loss of quality of life. Therefore, the prevention and treatment of paclitaxel-induced peripheral neuropathy are major concerns in clinical cancer therapy. However, the detailed mechanisms have not been fully elucidated. It has recently been reported that allelic variability in the Charcot-Marie-Tooth disease (CMT) genes, mitofusin 2 (MFN2), Rho guanine nucleotide exchange factor 10 (ARHGEF10), and periaxin (PRX), affected paclitaxel-induced peripheral neuropathy in clinical cases. Therefore, we hypothesized that paclitaxel may induce peripheral neuropathy due to changes in Mfn2, Arhgef10, and Prx mRNA expression. Paclitaxel (6mg/kg) was administered intraperitoneally, on two consecutive days per week for 4 weeks in rats. Paclitaxel-induced peripheral neuropathy was measured by the von Frey test and acetone test, mechanical allodynia, and cold hyperalgesia, respectively, on days 0, 3, 10, 17, and 24. Mfn2, Arhgef10, and Prx mRNA expression in the spinal cord were analyzed by qRT-PCR on days 3 and 24. Paclitaxel induced mechanical allodynia from days 17-24, but did not induce cold hyperalgesia. In addition, paclitaxel reduced Mfn2 mRNA expression, but not Arhgef10 or Prx mRNA expression, on days 3 and 24. In addition, Mfn2 mRNA level was decreased before the appearance of mechanical allodynia. The results of the present study suggest that a reduction in Mfn2 mRNA expression contributes to paclitaxel-induced mechanical allodynia.

Coffee, its roasted form, and their residues cause birth failure and shorten lifespan in dengue vectors.

In dengue mosquitoes, successful embryonic development and long lifespan are key determinants for the persistence of both virus and vector. Therefore, targeting the egg stage and vector lifespan would be expected to have greater impacts than larvicides or adulticides, both strategies that have lost effectiveness due to the development of resistance. Therefore, there is now a pressing need to find novel chemical means of vector control. Coffee contains many chemicals, and its waste, which has become a growing environmental concern, is as rich in toxicants as the green coffee beans; these chemicals do not have a history of resistance in insects, but some are lost in the roasting process. We examined whether exposure to coffee during embryonic development could alter larval eclosion and lifespan of dengue vectors. A series of bioassays with different coffee forms and their residues indicated that larval eclosion responses of Aedes albopictus and Ae. aegypti were appreciably lower when embryonic maturation occurred in environments containing coffee, especially roasted coffee crude extract (RCC). In addition, the lifespan of adults derived from eggs that hatched successfully in a coffee milieu was reduced, but this effect was less pronounced with roasted and green coffee extracts (RCU and GCU, respectively). Taken together, these findings suggested that coffee and its residues have embryocidal activities with impacts that are carried over onto the adult lifespan of dengue vectors. These effects may significantly reduce the vectorial capacity of these insects. Reutilizing coffee waste in vector control may also represent a realistic solution to the issues associated with its pollution.

Sweet waste extract uptake by a mosquito vector: Survival, biting, fecundity responses, and potential epidemiological significance.

In nature, adult mosquitoes typically utilize nectar as their main energy source, but they can switch to other as yet unidentified sugary fluids. Contemporary lifestyles, with their associated unwillingness to consume leftovers and improper disposal of waste, have resulted in the disposal of huge amounts of waste into the environment. Such refuse often contains unfinished food items, many of which contain sugar and some of which can collect water from rain and generate juices. Despite evidence that mosquitoes can feed on sugar-rich suspensions, semi-liquids, and decaying fruits, which can be abundant in garbage sites, the impacts of sweet waste fluids on dengue vectors are unknown. Here, we investigated the effects of extracts from some familiar sweet home waste items on key components of vectorial capacity of Aedes aegypti. Adult mosquitoes were fed one of five diets in this study: water (WAT); sucrose (SUG); bakery product (remnant of chocolate cake, BAK); dairy product (yogurt, YOG); and fruit (banana (BAN). Differences in survival, response time to host, and egg production were examined between groups. For both males and females, maintenance on BAK extract resulted in marked survival levels that were similar to those seen with SUG. Sweet waste extracts provided better substrates for survival compared to water, but this superiority was mostly seen with BAK. Females maintained on BAK, YOG, and BAN exhibited shorter response times to a host compared to their counterparts maintained on SUG. The levels of egg production were equivalent in waste extract- and SUG-fed females. The findings presented here illustrate the potential of sweet waste-derived fluids to contribute to the vectorial capacity of dengue vectors and suggest the necessity of readdressing the issue of waste disposal, especially that of unfinished sweet foods. Such approaches can be particularly relevant in dengue endemic areas where rainfall is frequent and waste collection infrequent.

Laboratory efficacy of mycoparasitic fungi (Aspergillus tubingensis and Trichoderma harzianum) against tropical bed bugs (Cimex hemipterus) (Hemiptera: Cimicidae)

Objective:To test the effectiveness of conidial spore formulations [Aspergillus tubingensis (A.tubingensis) and Trichoderma harzianum (T.harzianum)] against tropical bed bugs,Clnex hemipterus.Methods:Spore formulations were made from two fungal strains,T.harzianum and A.tubingensis.The bed bugs were exposed to the conidial spores placed soaked onto a fabric cloth for 1 h and the mortality counts were recorded daily until 14 days.Results:Mean survival times based on Kaplan-Meier survival analysis showed no significant differences between all the concentrations in both the fungal isolates:T.harzianum and A.tubingensis.However,the evaluation of both the isolates in terms of virulence resulted in low lethal hours in all the concentrations except for the high concentration ofA.tubingensis (LT50 =44.629 h) at the conidial exposure of 1 × 106 spores/mL.Rapid mortality of the bed bugs was observed from Day 6 to Day 12,ranging from 13％ to 90％ in all three concentrations of A.tubingensis.With reference to the T.harzianum exposure,the concentration of 1 × 104 spores/mL displayed a gradual increase in the percentage mortality of 90 on Day 14.Conclusions:Approaches to the bed bugs treatment should be explored in-depth using a natural biological agent like fungus especially A.tubingensis to reduce this pest population,in order to replace chemical methods.

Enhancement and regulation effect of myrcene on antibody response in immunization with ovalbumin and Ag85B in mice.

BACKGROUND: MF59, which is an adjuvant belonging to C30 member of the terpene family, is a T helper type-2 (Th2)-biased immune enhancer. Our previous studies showed that pyriproxyfen, a member of the terpene family with fewer carbon atoms (C20) than MF59, enhanced active T helper type-1 (Th1)-biased immune responses. OBJECTIVE: This study was performed to investigate the enhancement of antigen-specific immune responses by myrcene, a member of the terpene family with fewer carbon atoms (C10) than pyriproxyfen. METHOD: Ovalbumin (OVA) was used as an antigen to determine the effects of myrcene on the immune response. The IgG subtypes and cytokines induced by immunization of OVA with or without myrcene were monitored. Thereafter, we determined the effects of myrcene in the immune response against Ag85B, which is a dominant protective antigen for tuberculosis. RESULTS: The results showed that 0.8 mg/dose of myrcene enhanced antigen-specific total IgG immune response to OVA. Direct mixing of the antigen with myrcene was required for the enhancement of antibody production. Myrcene increased OVA-specific IgG2a titer, suggesting induction of Th1-immune response. The level of Th1 cytokines, IFN-γ was increased at 8 weeks after immunization, although IL-13 was also increased at the same time point. However, finally myrcene was found to increase Ag85B-specific total IgG titers at 5 weeks and specific IgG2a titer was increased at both 5 and 8 weeks. The results suggested that myrcene could enhance Th1 immune response. CONCLUSIONS: Myrcene enhanced specific immune responses against OVA and Ag85B. This study suggested the tendency of the enhancement of Th1 immune response by myrcene.

Exposure of a Dengue Vector to Tea and Its Waste: Survival, Developmental Consequences, and Significance for Pest Management.

Dengue mosquitoes are evolving into a broader global public health menace, with relentless outbreaks and the rise in number of Zika virus disease cases as reminders of the continued hazard associated with Aedes vectors. The use of chemical insecticides-the principal strategy against mosquito vectors-has been greatly impeded due to the development of insecticide resistance and the shrinking spectrum of effective agents. Therefore, there is a pressing need for new chemistries for vector control. Tea contains hundreds of chemicals, and its waste, which has become a growing global environmental problem, is almost as rich in toxicants as green leaves. This paper presents the toxic and sublethal effects of different crude extracts of tea on Aedes albopictus. The survival rates of larvae exposed to tea extracts, especially fresh tea extract (FTE), were markedly lower than those in the control treatment group. In addition to this immediate toxicity against different developmental stages, the extracts tested caused a broad range of sublethal effects. The developmental time was clearly longer in containers with tea, especially in those with young larvae (YL) and FTE. Among the survivors, pupation success was reduced in containers with tea, which also produced low adult emergence rates with increasing tea concentration. The production of eggs tended to be reduced in females derived from the tea treatment groups. These indirect effects of tea extracts on Ae. albopictus exhibited different patterns according to the exposed larval stage. Taken together, these findings indicate that tea and its waste affect most key components of Ae. albopictus vectorial capacity and may be useful for dengue control. Reusing tea waste in vector control could also be a practical solution to the problems associated with its pollution.

Recombinant human soluble thrombomodulin ameliorates cerebral ischemic injury through a high-mobility group box 1 inhibitory mechanism without hemorrhagic complications in mice.

BACKGROUND: It has been reported that recombinant human soluble thrombomodulin (rhsTM) has a high-mobility group box (HMGB)1 inhibitory effect. Some investigators reported that HMGB1 is associated with ischemic stroke. However, there have been no previous studies to determine whether rhsTM can ameliorate cerebral ischemic injury through its HMGB1 inhibitory mechanism in ischemic stroke. We investigated the effects of rhsTM on cerebral ischemic injury in a 4-h middle cerebral artery occlusion (MCAO) murine model. METHODS: rhsTM (1 or 5mg/kg, i.v.) was administered immediately after 4-h MCAO. Infarct volume, motor coordination, plasma HMGB1 level, and hemorrhage volume were evaluated 24h after 4-h MCAO. RESULTS: The infarct volume (P<0.05) was reduced by rhsTM in mice subjected to 4-h MCAO in a dose-dependent manner. Moreover, rhsTM (5mg/kg) significantly improved motor coordination determined by the rotarod test (P<0.05), and significantly decreased plasma HMGB1 level compared with vehicle-treated controls (P<0.001). In addition, there was no difference in hemorrhage volume between vehicle-treated controls and the rhsTM treatment group. CONCLUSIONS: This represents the first report that rhsTM ameliorates cerebral ischemic injury through an HMGB1 inhibitory mechanism without hemorrhagic complications in mice. Taken together, these observations indicate a palliative effect of rhsTM and suggest new therapeutic possibilities for treatment of ischemic stroke via inhibition of HMGB1.

Delayed treatment with ADAMTS13 ameliorates cerebral ischemic injury without hemorrhagic complication.

Tissue plasminogen activator (tPA) is the only approved therapy for acute ischemic stroke. However, delayed tPA treatment increases the risk of cerebral hemorrhage and can result in exacerbation of nerve injury. ADAMTS13, a von Willebrand factor (VWF) cleaving protease, has a protective effect against ischemic brain injury and may reduce bleeding risk by cleaving VWF. We examined whether ADAMTS13 has a longer therapeutic time window in ischemic stroke than tPA in mice subjected to middle cerebral artery occlusion (MCAO). ADAMTS13 (0.1mg/kg) or tPA (10mg/kg) was administered i.v., immediately after reperfusion of after 2-h or 4-h MCAO for comparison of the therapeutic time windows in ischemic stroke. Infarct volume, hemorrhagic volume, plasma high-mobility group box1 (HMGB1) levels and cerebral blood flow were measured 24h after MCAO. Both ADAMTS13 and tPA improved the infarct volume without hemorrhagic complications in 2-h MCAO mice. On the other hand, ADAMTS13 reduced the infarct volume and plasma HMGB1 levels, and improved cerebral blood flow without hemorrhagic complications in 4-h MCAO mice, but tPA was not effective and these animals showed massive intracerebral hemorrhage. These results indicated that ADAMTS13 has a longer therapeutic time window in ischemic stroke than tPA, and ADAMTS13 may be useful as a new therapeutic agent for ischemic stroke.