RÉSUMÉ
BACKGROUND & OBJECTIVES: In the present study, Icon®Life net, a long-lasting polyethylene net, 100 denier and bursting strength of minimum 280 kpa incorporated with deltamethrin @ 65 mg/m2 was evaluated for its efficacy in reducing the density of malaria vector Anopheles culicifacies and impact on malaria prevalence in a malaria endemic area of District Gautam Budh Nagar, India. METHODS: Wash resistance of Icon®Life LLIN was determined up to 20 serial washings using An. culicifacies in cone bioassays under field conditions. Efficacy of Icon®Life LLIN was determined in the field in three sets of villages in District Gautam Budh Nagar (Uttar Pradesh), India, selected randomly for the intervention with Icon®Life LLIN, untreated nets and a control without any intervention for the period of August 2008-July 2009. Entomological and malariometric indices in all the three villages were compared during pre- and post-intervention periods for one year against An. culicifacies. A survey was also conducted in the village provided with Icon®Life LLIN to assessing the perception of community regarding acceptance of these nets by the community. RESULTS: In cone bioassays on Icon®Life LLIN with An. culicifacies, >95% knockdown within 1 h and 100% mortality after 24 h exposure were reported even after 20× serial washings under field conditions. Results of the field study revealed reduced entry rate, resting density and parity rate of An. culicifacies in the village with Icon®Life LLIN when compared to no net and untreated net villages. Number of malaria cases reported were less in the Icon®Life LLIN used villages when compared to other two villages. The community compliance and acceptance was high and no adverse health events were reported by the households using these nets. CONCLUSIONS: Icon®Life LLIN is an effective intervention for the control of An. culicifacies transmitted malaria in India. Long-term studies are indicated for the duration of effectiveness and to ascertain the epidemiological impact of the use of Icon®Life nets.
Sujet(s)
Anopheles/effets des médicaments et des substances chimiques , Moustiquaires de lit traitées aux insecticides/statistiques et données numériques , Paludisme/prévention et contrôle , Lutte contre les moustiques/méthodes , Animaux , Anopheles/parasitologie , Femelle , Inde , Insecticides/pharmacologie , Paludisme/transmission , Malathion/pharmacologie , Nitriles/administration et posologie , Nitriles/composition chimique , Densité de population , Prévalence , Pyréthrines/administration et posologie , Pyréthrines/composition chimique , Saisons , Facteurs tempsRÉSUMÉ
BACKGROUND & OBJECTIVES: Prevention of malaria is a major technical and operational problem in displaced and mobile populations such as refugee camps and temporary labour settlements. Insecticide incorporated plastic sheeting is a new technology to control mosquitoes in emergency shelters and also temporary habitations at different locations. In view of this, efficacy of ZeroFly® , an insecticide incorporated plastic sheeting (factory treated with deltamethrin 2.0 g/kg or 265 mg/m2 ) was evaluated for its efficacy against malaria vectors and its impact on malaria incidence in temporary labour settlements in two urban areas in India. METHODS: This trial was conducted in two labour settlements in two urban areas, Delhi and Noida (U.P.), India with ~ 250 populations. In an area, two localities were selected for intervention with ZeroFly and untreated plastic sheets (control). Entomological and epidemiological data were collected using standard methods for one year. RESULTS: Baseline studies on the susceptibility of mosquitoes in Delhi and Noida areas revealed 100% susceptibility of the malaria vector species Anopheles culicifacies and An. stephensi to deltamethrin. Cone bioassay tests performed against An. culicifacies and An. stephensi to determine the efficacy of ZeroFly sheets showed 100% mortality against An. culicifacies and An. stephensi with 3 min exposure and after 24 h recovery period. Against Culex quinquefasciatus and housefly 100% mortality was obtained after 30 min of exposure period. Intervention with the ZeroFly plastic sheets resulted in almost complete reduction in the resting density of An. culicifacies and An. stephensi, the two major malaria vectors and also in the reduction of malaria cases in ZeroFly camps as compared to control camps. The ZeroFly plastic sheeting was found to be safe for human. Barring some complaints of skin irritation and itching, which were temporary in nature, no adverse health effects were reported by the users. The community acceptance was high. CONCLUSION: Results of the present study revealed that ZeroFly® plastic sheeting is highly effective in reducing the indoor resting density of mosquitoes, man -vector contact and malaria incidences in labour populations living in temporary shelters.
Sujet(s)
Anopheles/effets des médicaments et des substances chimiques , Literie et linges , Culex/effets des médicaments et des substances chimiques , Lutte contre les insectes/méthodes , Insecticides/pharmacologie , Paludisme/épidémiologie , Animaux , Anopheles/croissance et développement , Culex/croissance et développement , Femelle , Humains , Incidence , Inde/épidémiologie , Paludisme/prévention et contrôle , MâleRÉSUMÉ
BACKGROUND & OBJECTIVES: Repellents are commonly used personal protection measures to avoid mosquito bites. In the present study, Advanced Odomos cream (12% N, N-diethyl-benzamide) was tested for its efficacy against mosquitoes in comparison to DEET (N,N-diethyl-3-methyl benzamide). METHODS: Bioassays were conducted to assess the repellency of Advanced Odomos and DEET creams against Anopheles stephensi and Aedes aegypti. Their efficacy was tested on human volunteers applied with different concentrations of test creams ranging from 1 to 12 mg/cm 2 and by exposing them to mosquitoes at hourly intervals. Field evaluation was also carried out to test the duration of protection of the test creams against Anopheles and Aedes mosquitoes during whole night and day time collections, respectively on human volunteers. Mosquito collections were done using torch light and aspirator. RESULTS: Complete (100%) protection was achieved at 10 mg/cm 2 cream formulation of Advanced Odomos (1.2 mg a.i/cm 2 ) dose against An. stephensi and 12 mg/cm 2 (1.44 mg a.i./cm 2 ) against Ae. aegypti on human baits. There was no statistically significant differences in per cent protection against mosquito bites between Advanced Odomos and DEET cream (P>0.05) in respective doses. Complete protection up to 11 h was observed against Anopheles mosquitoes during whole night collections and up to 6 h against Ae. aegypti in day time collections. No adverse reactions such as itching, irritation, vomiting, nausea, etc. were reported by the volunteers. INTERPRETATION & CONCLUSIONS: Advanced Odomos cream applied at 10 mg/cm 2 concentration provided 100% protection from Anopheles mosquitoes up to 11 h whereas about 6 h protection was recorded against Ae. aegypti. The laboratory and field trials indicate that for longer protection against Anopheles mosquitoes 10 mg/cm 2 will be appropriate and in case of Ae. aegypti more than 10 mg/cm 2 application is required for complete protection. In conclusion, the Advanced Odomos cream was comparable to the known repellent cream DEET for prolonged protection against malaria and dengue vectors.
Sujet(s)
Culicidae , N,N-Diéthyl-méta-toluamide/analogues et dérivés , Morsures et piqûres d'insectes/prévention et contrôle , Insectifuges/administration et posologie , Vecteurs insectes , Administration par voie topique , Aedes , Animaux , Anopheles , N,N-Diéthyl-méta-toluamide/administration et posologie , HumainsRÉSUMÉ
Long-lasting insecticidal nets (LLIN) have been developed for wash resistance and long-lasting effects against mosquito vectors. In this study we evaluated 2 LLIN products, Olyset net and Permanet 2.0, washed for 0, 5, 10, 15, and 20 times, against Anopheles stephensi, an urban malaria vector in India. We assessed the wash resistance and efficacy of these nets in relation to bloodfeeding inhibition and percent mortality in cone and tunnel test bioassays. Both Olyset and Permanet showed >80% mortality of An. stephensi in cone bioassays after 20 washes. In tunnel tests there was no significant difference between Olyset and Permanet 2.0 in causing total mosquito mortality (immediate and delayed) up to 10 washes and bloodfeeding inhibition and entry rate up to 15 washes. After the 20th wash, Permanet 2.0 was significantly more effective than the Olyset net in causing total mosquito mortality, whereas Olyset net showed less bloodfeeding and entry of mosquitoes as compared to Permanet 2.0. There was a gradual decline in efficacy of both LLIN products as the number of washings increased. Cone bioassays indicated a strong wash resistance in both the LLIN products after 20 washes. However, the tunnel tests demonstrated a gradual decline in efficacy of both products with the number of washings.
Sujet(s)
Anopheles/effets des médicaments et des substances chimiques , Moustiquaires de lit traitées aux insecticides , Blanchissage , Nitriles/pharmacologie , Perméthrine/pharmacologie , Pyréthrines/pharmacologie , Animaux , Comportement alimentaire , Inde , Insecticides/composition chimique , Insecticides/pharmacologie , Nitriles/composition chimique , Perméthrine/composition chimique , Pyréthrines/composition chimiqueRÉSUMÉ
BACKGROUND & OBJECTIVES: Long-lasting insecticidal nets (LLINs) have been introduced in India recently into the vector control programme. A study was undertaken to assess the community perception regarding use of LLIN, their acceptability, collateral benefits, etc. in certain villages of District Gautam Budh Nagar, Uttar Pradesh, India where LLINs are in use by the community. METHOD: A randomized community-based survey was undertaken during April- May 2009 covering 596 respondents in LLIN villages where LLINs have been distributed along with 307 respondents in untreated net villages where untreated nets were distributed using structured questionnaire. Qualitative data were collected and the difference in proportion was calculated by z-test. RESULTS: A substantial number of respondents had good knowledge of the symptoms of malaria. According to respondents, LLINs were very much effective in bringing down the malaria incidence in their families. About 98.3% of the respondents asserted the use of LLINs as their use not only reduced the number of mosquitoes as well as other non-target insects, but also reduced the malaria incidence. About 93.2% of the respondents were ready to purchase LLINs if available at nominal prices. All the respondents were satisfied about the performance of the LLINs in reducing the mosquito nuisance, safety of use and collateral benefits in LLIN villages. CONCLUSION: LLINs are safe, socially acceptable and should be promoted for vector control to reduce the disease burden in the communities.
Sujet(s)
Attitude envers la santé , Paludisme/prévention et contrôle , Paludisme/psychologie , Lutte contre les moustiques/méthodes , Moustiquaires/statistiques et données numériques , Santé en zone rurale , Adulte , Femelle , Humains , Inde/épidémiologie , Paludisme/épidémiologie , Mâle , Acceptation des soins par les patients , Caractéristiques de l'habitat , Jeune adulteSujet(s)
Culicidae , Insecticides , Pyréthrines , Aérosols , Animaux , Dosage biologique , Relation dose-effet des médicaments , IndeRÉSUMÉ
BACKGROUND & OBJECTIVE: A longitudinal study was carried out to assess the impact of indoor residual spray with Vectron 20 WP (etofenprox) against Anopheles culicifacies and on malaria transmission in a selected village of Dadri primary health centre (PHC), District Gautam Budh Nagar, Uttar Pradesh, India. METHODS: Two villages, namely Patadi and Anandpur in District Gautam Budh Nagar, Uttar Pradesh, with similar malaria incidence and vector prevalence were selected for the present evaluation. In one village two rounds of indoor spraying of etofenprox (0.1 g/m(2)) were done at an interval of 12 wk and the other village was kept as control where no intervention except intensive active surveillance for early detection and prompt treatment (EDPT) was undertaken during the study period. Entomological and epidemiological data were collected using standard procedures. RESULTS: Persistence of the effectiveness of etofenprox against An. culicifacies was observed up to 12 wk. Spraying of etofenprox significantly reduced the density (P<0.001) and proportion of parous An. culicifacies mosquitoes (P<0.05) in the experimental village. There was a significant reduction in malaria cases in the experimental village during the post-spray period when compared to the control village (P<0.05). No adverse effect was reported by the spraymen and inhabitants during and after the spray. INTERPRETATION & CONCLUSION: Indoor residual spray of etofenprox (0.1 g/m(2)) with an interval of three months in between two rounds of spray produced the desired impact in reducing the indoor resting density of vector mosquitoes and also in curtailing malaria transmission in the sprayed village when compared with the control village without spray.
Sujet(s)
Anopheles/effets des médicaments et des substances chimiques , Insecticides/toxicité , Paludisme/prévention et contrôle , Pyréthrines/toxicité , Animaux , Anopheles/pathogénicité , Relation dose-effet des médicaments , Humains , Inde , Études longitudinales , Paludisme/transmissionRÉSUMÉ
Cannabinoid receptor activation has been shown to modulate both neurotransmission (CB(1)) and neuroinflammatory (CB(2)) responses. There are conflicting reports in the literature describing the influence of cannabinoid receptor activation on ischemic/reperfusion injury. The goal of this study was to evaluate how changing the balance between CB(1) and CB(2) activation following cerebral ischemia influences outcome. CB(1) and CB(2) expression were tested at different times after transient middle cerebral artery occlusion (MCAO) in mice by real-time RT-PCR. Animals subjected to 1 h MCAO were randomly assigned to receive different treatments: a CB(1) antagonist, a CB(2) antagonist, a CB(2) agonist, a CB(1) antagonist plus CB(2) agonist, a CB(2) antagonist plus CB(2) agonist or an equal volume of vehicle as control. Cerebral blood flow was continuously monitored during ischemia; cerebral infarction and neurological deficit were tested 24 h after MCAO. Cerebral CB(1) and CB(2) mRNA expression undertook dynamic changes during cerebral ischemia. The selective CB(1) antagonist significantly decreased cerebral infarction by 47%; the selective CB(2) antagonist increased infarction by 26% after 1 h MCAO followed by 23 h reperfusion in mice. The most striking changes were obtained by combining a CB(1) antagonist with a CB(2) agonist. This combination elevated the cerebral blood flow during ischemia and reduced infarction by 75%. In conclusion, during cerebral ischemia/reperfusion injury, inhibition of CB(1) receptor activation is protective while inhibition of CB(2) receptor activation is detrimental. The greatest degree of neuroprotection was obtained by combining an inhibitor of CB(1) activation with an exogenous CB(2) agonist.
Sujet(s)
Encéphalopathie ischémique/traitement médicamenteux , Modulateurs des récepteurs de cannabinoïdes/pharmacologie , Neuroprotecteurs/pharmacologie , Récepteur cannabinoïde de type CB1/métabolisme , Récepteur cannabinoïde de type CB2/métabolisme , Lésion d'ischémie-reperfusion/traitement médicamenteux , Animaux , Encéphalopathie ischémique/métabolisme , Encéphalopathie ischémique/physiopathologie , Modulateurs des récepteurs de cannabinoïdes/métabolisme , Modulateurs des récepteurs de cannabinoïdes/usage thérapeutique , Cannabinoïdes/pharmacologie , Cannabinoïdes/usage thérapeutique , Cortex cérébral/effets des médicaments et des substances chimiques , Cortex cérébral/métabolisme , Cortex cérébral/physiopathologie , Infarctus cérébral/traitement médicamenteux , Infarctus cérébral/métabolisme , Infarctus cérébral/prévention et contrôle , Association médicamenteuse , Synergie des médicaments , Infarctus du territoire de l'artère cérébrale moyenne/traitement médicamenteux , Infarctus du territoire de l'artère cérébrale moyenne/métabolisme , Infarctus du territoire de l'artère cérébrale moyenne/physiopathologie , Mâle , Souris , Souris de lignée C57BL , Neuroprotecteurs/usage thérapeutique , ARN messager/effets des médicaments et des substances chimiques , ARN messager/métabolisme , Récepteur cannabinoïde de type CB1/effets des médicaments et des substances chimiques , Récepteur cannabinoïde de type CB1/génétique , Récepteur cannabinoïde de type CB2/effets des médicaments et des substances chimiques , Récepteur cannabinoïde de type CB2/génétique , Lésion d'ischémie-reperfusion/métabolisme , Lésion d'ischémie-reperfusion/physiopathologie , Facteurs temps , Résultat thérapeutiqueRÉSUMÉ
Bioefficacy of PermaNet was evaluated in both the laboratory and field against Anopheles culicifacies and An. stephensi, major malaria vectors in India. Contact bioassays were carried out after repeated washings and ring net bioassays to determine the median knockdown time of mosquitoes. Three villages were selected for the field trial: in the 1st village PermaNets were distributed, in the 2nd village untreated nets were distributed, and the 3rd village was a control. Entomological data were collected using standard procedures. The PermaNet contact bioassays showed high mortality (>80%) even after 20 washes against both the vector species. The median knockdown time of An. culicifacies and An. stephensi was 392 and 480 sec when exposed to fresh PermaNets and 472 and 986 sec when exposed to PermaNets that had been washed 20 times, respectively. PermaNets showed high efficacy in reducing the person-vector contact as evidenced by reduced person-hour density in the PermaNet village. Long-term field trials are indicated to test the impact of use of PermaNets in controlling malaria.
Sujet(s)
Anopheles/effets des médicaments et des substances chimiques , Literie et linges , Insecticides/pharmacologie , Paludisme/transmission , Lutte contre les moustiques/méthodes , Animaux , Inde , Paludisme/prévention et contrôleRÉSUMÉ
BACKGROUND & OBJECTIVES: Efficacy of Olyset nets, long-lasting insecticidal nets were tested from August 2003 to August 2006 against Anopheles culicifacies, the vector which transmits 60% of all malaria cases in rural India. METHODS: Three villages in District Gautam Budh Nagar (Uttar Pradesh), India were selected for the trial and Olyset nets were distributed in one village, in another village untreated nets were distributed and the third village was kept as control where nets were not used. Entomological, and epidemiological data were collected using standard methods. RESULTS: The use of Olyset nets reduced the indoor resting density of An. culicifacies and also reduced mosquito entry into the structures where Olyset nets were used. No mosquitoes were caught landing on the Olyset nets. There was a reduction in the parity rate of An. culicifacies in the Olyset net village as compared with untreated net and no net villages. The impact of Olyset nets was observed on malaria incidence and only one case of Plasmodiumfalciparum malaria was reported in the Olyset net village but these continued to be found in the village with untreated nets and the control. CONCLUSION: Results of the present study confirmed that Olyset nets are highly effective in reducing the indoor resting density of mosquitoes, man-vector contact and malaria incidence.
Sujet(s)
Anopheles , Literie et linges , Vecteurs insectes , Insecticides/administration et posologie , Paludisme/prévention et contrôle , Paludisme/transmission , Animaux , Humains , Inde , Lutte contre les moustiques/méthodes , Santé en zone ruraleRÉSUMÉ
BACKGROUND AND PURPOSE: A nonpsychoactive constituent of the cannabis plant, cannabidiol has been demonstrated to have low affinity for both cannabinoid CB1 and CB2 receptors. We have shown previously that cannabidiol can enhance electrically evoked contractions of the mouse vas deferens, suggestive of inverse agonism. We have also shown that cannabidiol can antagonize cannabinoid receptor agonists in this tissue with a greater potency than we would expect from its poor affinity for cannabinoid receptors. This study aimed to investigate whether these properties of cannabidiol extend to CB1 receptors expressed in mouse brain and to human CB2 receptors that have been transfected into CHO cells. EXPERIMENTAL APPROACH: The [35S]GTPS binding assay was used to determine both the efficacy of cannabidiol and the ability of cannabidiol to antagonize cannabinoid receptor agonists (CP55940 and R-(+)-WIN55212) at the mouse CB1 and the human CB2 receptor. KEY RESULTS: This paper reports firstly that cannabidiol displays inverse agonism at the human CB2 receptor. Secondly, we demonstrate that cannabidiol is a high potency antagonist of cannabinoid receptor agonists in mouse brain and in membranes from CHO cells transfected with human CB2 receptors. CONCLUSIONS AND IMPLICATIONS: This study has provided the first evidence that cannabidiol can display CB2 receptor inverse agonism, an action that appears to be responsible for its antagonism of CP55940 at the human CB2 receptor. The ability of cannabidiol to behave as a CB2 receptor inverse agonist may contribute to its documented anti-inflammatory properties.
Sujet(s)
Anti-inflammatoires/pharmacologie , Benzoxazines/antagonistes et inhibiteurs , Encéphale/effets des médicaments et des substances chimiques , Cannabidiol/pharmacologie , Agonistes des récepteurs de cannabinoïdes , Cyclohexanes/antagonistes et inhibiteurs , Morpholines/antagonistes et inhibiteurs , Naphtalènes/antagonistes et inhibiteurs , Phénols/antagonistes et inhibiteurs , Animaux , Anti-inflammatoires/métabolisme , Benzoxazines/pharmacologie , Encéphale/métabolisme , Cellules CHO , Camphanes/pharmacologie , Cannabidiol/métabolisme , Antagonistes des récepteurs de cannabinoïdes , Membrane cellulaire/effets des médicaments et des substances chimiques , Membrane cellulaire/métabolisme , Cricetinae , Cricetulus , Cyclohexanes/pharmacologie , Cyclohexanols , Relation dose-effet des médicaments , Guanosine 5'-O-(3-thiotriphosphate)/métabolisme , Humains , Techniques in vitro , Souris , Souris de lignée C57BL , Souris knockout , Morpholines/pharmacologie , Naphtalènes/pharmacologie , Phénols/pharmacologie , Pipéridines/pharmacologie , Liaison aux protéines , Pyrazoles/pharmacologie , Récepteur cannabinoïde de type CB1/agonistes , Récepteur cannabinoïde de type CB2/agonistes , Récepteurs de cannabinoïdes/génétique , Récepteurs de cannabinoïdes/métabolisme , Rimonabant , TransfectionRÉSUMÉ
BACKGROUND AND PURPOSE: To follow up in vitro evidence that Delta(9)-tetrahydrocannabivarin extracted from cannabis (eDelta(9)-THCV) is a CB(1) receptor antagonist by establishing whether synthetic Delta(9)-tetrahydrocannabivarin (O-4394) and Delta(8)-tetrahydrocannabivarin (O-4395) behave as CB(1) antagonists in vivo. EXPERIMENTAL APPROACH: O-4394 and O-4395 were compared with eDelta(9)-THCV as displacers of [(3)H]-CP55940 from specific CB(1) binding sites on mouse brain membranes and as antagonists of CP55940 in [(35)S]GTPgammaS binding assays performed with mouse brain membranes and of R-(+)-WIN55212 in mouse isolated vasa deferentia. Their ability to antagonize in vivo effects of 3 or 10 mg kg(-1) (i.v.) Delta(9)-tetrahydrocannabinol in mice was then investigated. KEY RESULTS: O-4394 and O-4395 exhibited similar potencies to eDelta(9)-THCV as displacers of [(3)H]-CP55940 (K (i)=46.6 and 64.4 nM, respectively) and as antagonists of CP55940 in the [(35)S]GTPgammaS binding assay (apparent K (B)=82.1 and 125.9 nM, respectively) and R-(+)-WIN55212 in the vas deferens (apparent K (B)=4.8 and 3.9 nM respectively). At i.v. doses of 0.1, 0.3, 1.0 and/or 3 mg kg(-1) O-4394 and O-4395 attenuated Delta(9)-tetrahydrocannabinol-induced anti-nociception (tail-flick test) and hypothermia (rectal temperature). O-4395 but not O-4394 also antagonized Delta(9)-tetrahydrocannabinol-induced ring immobility. By themselves, O-4395 and O-4394 induced ring immobility at 3 or 10 mg kg(-1) (i.v.) and antinociception at doses above 10 mg kg(-1) (i.v.). O-4395 also induced hypothermia at 3 mg kg(-1) (i.v.) and above. CONCLUSIONS AND IMPLICATIONS: O-4394 and O-4395 exhibit similar in vitro potencies to eDelta(9)-THCV as CB(1) receptor ligands and as antagonists of cannabinoid receptor agonists and can antagonize Delta(9)-tetrahydrocannabinol in vivo.
Sujet(s)
Encéphale/effets des médicaments et des substances chimiques , Antagonistes des récepteurs de cannabinoïdes , Dronabinol/analogues et dérivés , Dronabinol/antagonistes et inhibiteurs , Psychoanaleptiques/antagonistes et inhibiteurs , Conduit déférent/effets des médicaments et des substances chimiques , Analgésiques non narcotiques/antagonistes et inhibiteurs , Animaux , Benzoxazines/pharmacologie , Fixation compétitive , Température du corps/effets des médicaments et des substances chimiques , Encéphale/métabolisme , Agonistes des récepteurs de cannabinoïdes , Cyclohexanes/métabolisme , Cyclohexanes/pharmacologie , Cyclohexanols , Relation dose-effet des médicaments , Dronabinol/métabolisme , Dronabinol/pharmacologie , Stimulation électrique , Guanosine 5'-O-(3-thiotriphosphate)/métabolisme , Techniques in vitro , Locomotion/effets des médicaments et des substances chimiques , Mâle , Souris , Souris de lignée ICR , Morpholines/pharmacologie , Contraction musculaire/effets des médicaments et des substances chimiques , Muscles lisses/effets des médicaments et des substances chimiques , Muscles lisses/métabolisme , Naphtalènes/pharmacologie , Mesure de la douleur , Seuil nociceptif/effets des médicaments et des substances chimiques , Phénols/métabolisme , Phénols/pharmacologie , Liaison aux protéines , Récepteur cannabinoïde de type CB1/antagonistes et inhibiteurs , Récepteur cannabinoïde de type CB2/antagonistes et inhibiteurs , Récepteurs de cannabinoïdes/métabolisme , Conduit déférent/métabolismeRÉSUMÉ
Olyset nets are highly effective in killing anopheline mosquitoes within 3 min of exposure, as evidenced in cone bioassay tests. These nets also showed their efficacy on other vector mosquitoes (Aedes aegypti and Cx. quinquefasciatus) at higher exposure periods. The efficacy remained at approximately 90% even after 20 washings at an interval of 24 h against Anopheles culicifacies and Cx. quinquefasciatus. Use of the nets inside the house also resulted in drastic reduction of daytime resting density of mosquitoes because of high repellency, excitorepellency, and killing action of the nets. Pilot studies are indicated to evaluate the impact of use of Olyset nets on vector-borne diseases, particularly malaria, and its cost-effectiveness in comparison to conventional indoor residual spraying.
Sujet(s)
Lutte contre les moustiques/méthodes , Aedes , Animaux , Anopheles , Literie et linges , Culex , Inde , PerméthrineRÉSUMÉ
BACKGROUND AND OBJECTIVES: Various plant-based products are safe and biodegradable alternatives to synthetic chemicals for use against mosquitoes. Oil of Pinus longifolia is traditionally used for protection against mosquitoes in some rural areas but there is no documented report of its use against mosquitoes. The present study was undertaken to scientifically evaluate the activity of Pine oil against mosquitoes. METHODS: The oil was procured from the market and its contents were chemically analysed. Larvicidal activity of oil was tested in laboratory bioassays, while repellent action was studied during whole night bait collections in field by direct application on the skin and after its impregnation on mats. RESULTS: Results showed varying degree of larvicidal activity of Pine oil against mosquitoes with LC50 values ranging between 82 and 112 ppm. The Pine oil had strong repellent action against mosquitoes as it provided 100% protection against Anopheles culicifacies for 11 h and 97% protection against Culex quinquefasciatus for nine hours respectively. Electrically heated mats prepared from Pine oil provided, 94 and 88% protection against An. culicifacies and Cx. quinquefasciatus for 10 and seven hours respectively. INTERPRETAION AND CONCLUSION: Pine oil is effective against mosquito larvae at very higher doses which are not of any practical utility. However, Pine oil showed strong repellent action against An. culicifacies (malaria vector) and Cx. quinquefasciatus (pest mosquito). Thus its use could be popularised as mosquito repellent.
Sujet(s)
Culicidae , Insectifuges/composition chimique , Pinus/composition chimique , Huiles végétales/composition chimique , Animaux , Température élevée , Larve , Dose létale 50 , Spécificité d'espèceRÉSUMÉ
Hilmilin (diflubenzuron), an insect growth regulator, was tested for efficacy against Anopheles stephensi, Anopheles culicifacies, Aedes aegypti, and Culex quinquefasciatus in the laboratory and in field conditions. Fifty percent and 90% lethal concentrations (LC50 and LC90) of Hilmilin formulations were determined by exposing early 4th-stage larvae to serial dilutions of the formulation, and data were subjected to log probit analysis. Two doses (0.004 and 0.008 g/m2) were applied in different breeding habitats of mosquitoes with the help of stirrup pumps. Percent inhibition of adult emergence was compared according to a previously described procedure. Laboratory results revealed that both 25WP (wettable powder) and 22SL (semiliquid) formulations showed more or less the same degree of efficacy against tested mosquito species (P < 0.05). Of 4 species tested, An. stephensi was more susceptible, followed by An. culicifacies, Ae. aegypti, and Cx. quinquefasciatus. One hundred percent inhibition of adult emergence was observed at a dose of 0.0125 ppm (25WP and 22SL) against all mosquitoes tested in the laboratory. Both formulations showed almost similar effect when applied in the field at doses of 0.004 and 0.008 g/m2 in their respective preferential breeding habitats. However, the effect was more pronounced at a higher concentration (0.008 g/m2) against all species of mosquitoes. Hilmilin at a dose of 0.008 g/m2 can be used to contain mosquito breeding in stone quarries, pools, cement tanks, unused wells, unused coolers, and irrigation channels.
Sujet(s)
Aedes , Anopheles , Culex , Diflubenzuron , Insecticides , Animaux , Inde , Larve , Dose létale 50 , Facteurs tempsRÉSUMÉ
BACKGROUND & OBJECTIVES: In India, temephos and fenthion are used as larvicides in fresh and polluted waters. Since use of same insecticide may precipitate resistant, as an alternative bioefficacy of pirimiphos-methyl--an organophosphorus insecticide was evaluated against immatures of Anopheles and Culex species in different breeding habitats in District Ghaziabad (U.P.) and Goa. METHODS: Laboratory bioassays were carried out using standard WHO procedure. LC50 and LC90 were calculated using Probit analysis. Abbott's formula was used to calculate per cent corrected mortality in laboratory exposures while, Mulla's formula was applied for calculating per cent reduction in mosquito immatures under field conditions. RESULTS: Pirimiphos-methyl was found to be most effective against larvae of An. stephensi followed by An. culicifacies and Cx. quinquefasciatus. The LC50 and LC90 values against three species were 0.023, 0.032 and 0.04 ppm; and 0.045, 0.057 and 0.114 ppm respectively. In field, pirimiphos-methyl @ 200 g a.i./ha against Anopheles species and @ 300 g a.i./ha against Culex species can produce > 80% reduction in density of immatures up to one week in different habitats. Pirimiphos-methyl < 0.25 ppm is not toxic to fish. INTERPRETATION & CONCLUSION: Pirimiphos-methyl is more effective against anophelines in clean water than culicines in polluted water. This larvicide should not be used at a concentration above 0.25 ppm in habitats harbouring the larvivorous fish.
Sujet(s)
Anopheles/effets des médicaments et des substances chimiques , Culex/effets des médicaments et des substances chimiques , Vecteurs insectes/effets des médicaments et des substances chimiques , Insecticides/toxicité , Composés organothiophosphorés/toxicité , Animaux , Cyprinodontiformes , Relation dose-effet des médicaments , Inde , Larve/effets des médicaments et des substances chimiques , Dose létale 50 , EauRÉSUMÉ
BACKGROUND & OBJECTIVES: Indoor residual spraying of Reldan 40% EC @ 0.5 and 1 g/m2 was done in Tatarpur and Chauna villages, respectively in Dhaulana PHC, Distt. Ghaziabad (U.P.) to evaluate its impact against Anopheles culicifacies and malaria incidence. Results were compared with that of Piyawali village which was taken as control area. METHODS: Four rounds of spray were done from 1999--2000 in human dwellings and cattlesheds in experimental villages. Entomological parameters--man hour density, parity rate, sporozoite rate, etc. were monitored using standard procedures. Epidemiological indicators such as SPR, SFR, cases/000, Pf/000 were also calculated. Cone bioassays as per WHO method were also carried out to assess the persistence of the insecticide on different surfaces. RESULTS: Entomological results revealed that spraying of reldan @ 0.5 g/m2 resulted in significant reduction in adult densities of An. culicifacies in sprayed villages over the control village. Spraying also resulted in reduction of percent parous females, reduction in malaria incidence (p < 0.05). INTERPRETATION & CONCLUSION: Reldan showed high efficacy @ 0.5 g/m2 in controlling the densities of An. culicifacies and malaria incidence. However, double dosage of reldan @ 1 g/m2 can be used for comprehensive vector control provided > 95% spray coverage is achieved.
Sujet(s)
Anopheles , Chlorpyriphos/analogues et dérivés , Paludisme/prévention et contrôle , Lutte contre les moustiques/méthodes , Animaux , Humains , Incidence , Inde/épidémiologie , Paludisme/épidémiologieRÉSUMÉ
Bio-efficacy and operational feasibility of alphacypermethrin treated nets was evaluated in certain villages of District Ghaziabad (U.P.). Results revealed that poly-filament nylon nets treated with alphacypermethrin suspension concentrate (g/l) formulation @ 25 mg/m2 has shown repellent action (26.5 +/- 8.1), excito repellent action (93.7 +/- 8.1) and killing action (100%) against An. culicifacies landed on treated nets. Significant reduction in indoor resting density of An. culicifacies in human dwellings was also observed in treated nets village (p < 0.05). Instant killing action of treated nets did provide complete protection to inhabitants sleeping inside the net from An. culicifacies bites. The persistent use of nets by the inhabitants has also resulted significant reduction in malaria cases (p < 0.05). It was interesting to note that not even a single case of falciparum malaria was observed after distribution of treated nets in spite of the fact that at no point of time cent per cent compliance of net usage was observed during the study period. Bio-assay tests revealed that treated nets can produce up to 70% mortality in An. culicifacies for about 22 weeks and as such only one treatment with insecticide is required in a year in seasonal transmission area to protect from malaria. The study also revealed that treated nets can be stored at room temperature for about 10 months without loosing their efficacy suggesting thereby that malaria outbreaks can be tackled by the nets if adequate treated nets are stored in core problem districts. It was also revealed that An. culicifacies is a late night biter and as such treated nets can be used successfully against this species.
Sujet(s)
Literie et linges , Insecticides/pharmacologie , Paludisme/prévention et contrôle , Lutte contre les moustiques/méthodes , Pyréthrines/pharmacologie , Animaux , Anopheles/effets des médicaments et des substances chimiques , Culex/effets des médicaments et des substances chimiques , Études de faisabilité , Humains , Inde/épidémiologie , Paludisme/épidémiologie , Paludisme à Plasmodium falciparum/épidémiologie , Paludisme à Plasmodium falciparum/prévention et contrôle , Santé en zone rurale , Résultat thérapeutiqueRÉSUMÉ
The chemical strategies used for the synthesis of various ligands related to the endocannabinoid system namely anandamide (AEA), 2-arachidonylglycerol (2-Ara-Gl), CB1/(vanilloid receptors) VR1, anandamide membrane transporter (AMT) and fatty acid amide hydrolase (FAAH) are described in this review. In general, the chemical synthesis of analogs with changes in the head group of AEA was quite straightforward involving the conversion of an acid to an amide or an ester. Analogs which had modifications in the end pentyl chain were more difficult to synthesize and required multistep synthetic sequences to prepare the target compounds. A facile total synthesis of 2-Ara-Gl was reported and an HPLC procedure for its identification and quantification was developed, but because of the instability of 2-Ara-Gl another synthesis was developed so that it can be stored as the more stable phenylboronate ester. Similarly the chemical synthesis of various ligands in the remaining areas of CB1/VR1, AMT and FAAH are described. A summary of the present state of knowledge about the SAR in each area is presented to help in the design and synthesis of novel ligands for the future.
Sujet(s)
Acides gras insaturés/composition chimique , Amidohydrolases/antagonistes et inhibiteurs , Amidohydrolases/métabolisme , Animaux , Acides arachidoniques/composition chimique , Acides arachidoniques/métabolisme , Modulateurs des récepteurs de cannabinoïdes , Protéines de transport/antagonistes et inhibiteurs , Protéines de transport/composition chimique , Protéines de transport/métabolisme , Endocannabinoïdes , Antienzymes/synthèse chimique , Acides gras insaturés/métabolisme , Glycérides/composition chimique , Glycérides/métabolisme , Ligands , Amides gras polyinsaturés N-alkylés , Récepteurs de cannabinoïdes , Récepteurs des médicaments/agonistes , Récepteurs des médicaments/composition chimique , Récepteurs des médicaments/métabolisme , Relation structure-activitéRÉSUMÉ
Operational feasibility and bio-efficacy of alphacypermethrin treated curtains was evaluated in slum settlements of Andrews Ganj, New Delhi. Jute curtains treated with alphacypermethrin @ 100 mg/m2 were fixed on windows, doors and eves before on set of transmission and evaluations were carried out for two years. Entomological evaluation revealed that jute curtains treated with alphacypermethrin in Slum-I resulted drastic reduction in daytime indoor resting mosquitoes such as An. stephensi, Ae. aegypti and Cx. quinquefasciatus. Similarly, malaria incidence also reduced in the treated curtain used area when compared to that of in untreated curtain and without curtain areas. Bioassay tests on An. stephensi and Cx. quinquefasciatus showed that alphacypermethrin could produce > 70 per cent mortality up to six months in case of An. stephensi--a principal urban malaria vector and hence two rounds of treatment are sufficient in an year to protect inhabitants from malaria. The study indicates alphacypermethrin treated curtains could curtail malaria transmission in slum settlements and is operationally feasible in small houses and is also cost-effective.