RESUMEN
Mosquitoes are responsible for the death and debilitation of millions of people every year due to the pathogens they can transmit while blood feeding. While a handful of mosquitoes, namely those in the Aedes, Anopheles, and Culex genus, are the dominant vectors, many other species belonging to different genus are also involved in various pathogen cycles. Sabethes cyaneus is one of the many poorly understood mosquito species involved in the sylvatic cycle of Yellow Fever Virus. Here, we report the expression profile differences between male and female of Sa.cyaneus salivary glands (SGs). We find that female Sa.cyaneus SGs have 165 up-regulated and 18 down-regulated genes compared to male SGs. Most of the up-regulated genes have unknown functions, however, odorant binding proteins, such as those in the D7 protein family, and mucins were among the top 30 genes. We also performed various in vitro activity assays of female SGs. In the activity analysis we found that female SG extracts inhibit coagulation by blocking factor Xa and has endonuclease activity. Knowledge about mosquitoes and their physiology are important for understanding how different species differ in their ability to feed on and transmits pathogens to humans. These results provide us with an insight into the Sabethes SG activity and gene expression that expands our understanding of mosquito salivary glands.
Asunto(s)
Aedes , Anopheles , Humanos , Masculino , Femenino , Animales , Transcriptoma , Mosquitos Vectores , Glándulas Salivales/metabolismo , Anopheles/genética , Anopheles/metabolismo , Aedes/genéticaRESUMEN
To successfully feed on blood, hematophagous arthropods must combat the host's natural hemostatic and inflammatory responses. Salivary proteins of blood-feeding insects such as mosquitoes contain compounds that inhibit these common host defenses against blood loss, including vasoconstriction, platelet aggregation, blood clotting, pain, and itching. The D7 proteins are some of the most abundantly expressed proteins in female mosquito salivary glands and have been implicated in inhibiting host hemostatic and inflammatory responses. Anopheles gambiae, the primary vector of malaria, expresses three D7 long-form and five D7 short-form proteins. Previous studies have characterized the AngaD7 short-forms, but the D7 long-form proteins have not yet been characterized in detail. Here, we characterized the A. gambiae D7 long-forms by first determining their binding kinetics to hemostatic agonists such as leukotrienes and serotonin, which are potent activators of vasoconstriction, edema formation, and postcapillary venule leakage, followed by ex vivo functional assays. We found that AngaD7L1 binds leukotriene C4 and thromboxane A2 analog U-46619; AngaD7L2 weakly binds leukotrienes B4 and D4; and AngaD7L3 binds serotonin. Subsequent functional assays confirmed AngaD7L1 inhibits U-46619-induced platelet aggregation and vasoconstriction, and AngaD7L3 inhibits serotonin-induced platelet aggregation and vasoconstriction. It is therefore possible that AngaD7L proteins counteract host hemostasis by scavenging these mediators. Finally, we demonstrate that AngaD7L2 had a dose-dependent anticoagulant effect via the intrinsic coagulation pathway by interacting with factors XII, XIIa, and XI. The uncovering of these interactions in the present study will be essential for comprehensive understanding of the vector-host biochemical interface.
Asunto(s)
Anopheles , Hemostáticos , Proteínas de Insectos/metabolismo , Proteínas y Péptidos Salivales/metabolismo , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Animales , Anopheles/química , Femenino , Hemostáticos/metabolismo , Leucotrienos/metabolismo , Malaria , Mosquitos Vectores , Serotonina/metabolismo , Serotonina/farmacologíaRESUMEN
Aedes aegypti is an important vector of human viral diseases. This mosquito is distributed globally and thrives in urban environments, making it a serious risk to human health. Pyrethroid insecticides have been the mainstay for control of adult A. aegypti for decades, but resistance has evolved, making control problematic in some areas. One major mechanism of pyrethroid resistance is detoxification by cytochrome P450 monooxygenases (CYPs), commonly associated with the overexpression of one or more CYPs. Unfortunately, the molecular basis underlying this mechanism remains unknown. We used a combination of RNA-seq and proteomic analysis to evaluate the molecular basis of pyrethroid resistance in the highly resistant CKR strain of A. aegypti. The CKR strain has the resistance mechanisms from the well-studied Singapore (SP) strain introgressed into the susceptible Rockefeller (ROCK) strain genome. The RNA-seq and proteomics data were complimentary; each offering insights that the other technique did not provide. However, transcriptomic results did not quantitatively mirror results of the proteomics. There were 10 CYPs which had increased expression of both transcripts and proteins. These CYPs appeared to be largely trans-regulated, except for some CYPs for which we could not rule out gene duplication. We identified 65 genes and lncRNAs as potentially being responsible for elevating the expression of CYPs in CKR. Resistance was associated with multiple loci on chromosome 1 and at least one locus on chromosome 3. We also identified five CYPs that were overexpressed only as proteins, suggesting that stabilization of CYP proteins could be a mechanism of resistance. Future studies to increase the resolution of the resistance loci, and to examine the candidate genes and lncRNAs identified here will greatly enhance our understanding of CYP-mediated resistance in A. aegypti.
Asunto(s)
Aedes/efectos de los fármacos , Aedes/genética , Proteínas de Insectos/genética , Resistencia a los Insecticidas , Insecticidas/farmacología , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/genética , Piretrinas/farmacología , Aedes/metabolismo , Animales , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Proteínas de Insectos/metabolismo , Mosquitos Vectores/metabolismo , Proteómica , TranscriptomaRESUMEN
BACKGROUND: Volatile pyrethroid insecticides, such as transfluthrin, have received increasing attention for their potent repellent activities in recent years for controlling human disease vectors. It has been long understood that pyrethroids kill insects by promoting activation and inhibiting inactivation of voltage-gated sodium channels. However, the mechanism of pyrethroid repellency remains poorly understood and controversial. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that transfluthrin repels Aedes aegypti in a hand-in-cage assay at nonlethal concentrations as low as 1 ppm. Contrary to a previous report, transfluthrin does not elicit any electroantennogram (EAG) responses, indicating that it does not activate olfactory receptor neurons (ORNs). The 1S-cis isomer of transfluthrin, which does not activate sodium channels, does not elicit repellency. Mutations in the sodium channel gene that reduce the potency of transfluthrin on sodium channels decrease transfluthrin repellency but do not affect repellency by DEET. Furthermore, transfluthrin enhances DEET repellency. CONCLUSIONS/SIGNIFICANCE: These results provide a surprising example that sodium channel activation alone is sufficient to potently repel mosquitoes. Our findings of sodium channel activation as the principal mechanism of transfluthrin repellency and potentiation of DEET repellency have broad implications in future development of a new generation of dual-target repellent formulations to more effectively repel a variety of human disease vectors.
Asunto(s)
Aedes/efectos de los fármacos , Ciclopropanos/farmacología , Fluorobencenos/farmacología , Proteínas de Insectos/metabolismo , Repelentes de Insectos/farmacología , Canales de Sodio/metabolismo , Aedes/genética , Aedes/metabolismo , Animales , Ciclopropanos/química , Fluorobencenos/química , Proteínas de Insectos/genética , Repelentes de Insectos/química , Isomerismo , Canales de Sodio/genéticaRESUMEN
Pyrethrum extracts from flower heads of Chrysanthemum spp. have been used worldwide in insecticides and repellents. While the molecular mechanisms of its insecticidal action are known, the molecular basis of pyrethrum repellency remains a mystery. In this study, we find that the principal components of pyrethrum, pyrethrins, and a minor component, (E)-ß-farnesene (EBF), each activate a specific type of olfactory receptor neurons in Aedes aegypti mosquitoes. We identify Ae. aegypti odorant receptor 31 (AaOr31) as a cognate Or for EBF and find that Or31-mediated repellency is significantly synergized by pyrethrin-induced activation of voltage-gated sodium channels. Thus, pyrethrum exerts spatial repellency through a novel, dual-target mechanism. Elucidation of this two-target mechanism may have potential implications in the design and development of a new generation of synthetic repellents against major mosquito vectors of infectious diseases.
Asunto(s)
Chrysanthemum cinerariifolium/metabolismo , Culicidae/efectos de los fármacos , Repelentes de Insectos/farmacología , Insecticidas/farmacología , Piretrinas/farmacología , Aedes/efectos de los fármacos , Animales , Chrysanthemum cinerariifolium/genética , Técnicas de Inactivación de Genes , Control de Mosquitos , Mosquitos Vectores , Neuronas , Receptores Odorantes/genética , Canales de Sodio Activados por VoltajeRESUMEN
BACKGROUND: Aedes aegypti is an important vector of many human diseases and a serious threat to human health due to its wide geographic distribution and preference for human hosts. A. aegypti also has evolved widespread resistance to pyrethroids due to the extensive use of this insecticide class over the past decades. Mutations that cause insecticide resistance result in fitness costs in the absence of insecticides. The fitness costs of pyrethroid resistance mutations in A. aegypti are still poorly understood despite their implications for arbovirus transmission. METHODOLOGY/PRINCIPLE FINDINGS: We evaluated fitness based both on allele-competition and by measuring specific fitness components (i.e. life table and mating competition) to determine the costs of the different resistance mechanisms individually and in combination. We used four congenic A. aegypti strains: Rockefeller (ROCK) is susceptible to insecticides; KDR:ROCK (KR) contains only voltage-sensitive sodium channel (Vssc) mutations S989P+V1016G (kdr); CYP:ROCK (CR) contains only CYP-mediated resistance; and CYP+KDR:ROCK (CKR) contains both CYP-mediated resistance and kdr. The kdr allele frequency decreased over nine generations in the allele-competition study regardless of the presence of CYP-mediated resistance. Specific fitness costs were variable by strain and component measured. CR and CKR had a lower net reproductive rate (R0) than ROCK or KR, and KR was not different than ROCK. There was no correlation between the level of permethrin resistance conferred by the different mechanisms and their fitness cost ratio. We also found that CKR males had a reduced mating success relative to ROCK males when attempting to mate with ROCK females. CONCLUSIONS/SIGNIFICANCE: Both kdr and CYP-mediated resistance have a fitness cost affecting different physiological aspects of the mosquito. CYP-mediated resistance negatively affected adult longevity and mating competition, whereas the specific fitness costs of kdr remains elusive. Understanding fitness costs helps us determine whether and how quickly resistance will be lost after pesticide application has ceased.
Asunto(s)
Aedes/efectos de los fármacos , Aedes/genética , Resistencia a Medicamentos/genética , Aptitud Genética/genética , Insecticidas/farmacología , Piretrinas/farmacología , Animales , Humanos , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/genética , Canales de Sodio Activados por Voltaje/genéticaRESUMEN
The evolution of insecticide resistance is generally thought to be associated with a fitness cost in the absence of insecticide exposure. However, it is not clear how these fitness costs manifest or how universal this phenomenon is. To investigate this, we conducted a literature review of publications that studied fitness costs of insecticide resistance, selected papers that met our criteria for scientific rigor, and analyzed each class of insecticides separately as well as in aggregate. The more than 170 publications on fitness costs of insecticide resistance show that in 60% of the experiments there is a cost to having resistance, particularly for measurements of reversion of resistance and reproduction. There were differences between classes of insecticides, with fitness costs seen less commonly for organochlorines. There was considerable variation in the experiments performed. We suggest that future papers will have maximum value to the community if they quantitatively determine resistance levels, identify the resistance mechanisms present (and the associated mutations), have replicated experiments, use related strains (optimally congenic with the resistance mutation introgressed into different genetic backgrounds) and measure fitness by multiple metrics. Studies on the fitness costs of insecticide resistance will continue to enlighten our understanding of the evolutionary process and provide valuable information for resistance management. © 2021 Society of Chemical Industry.
Asunto(s)
Insecticidas , Aptitud Genética , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Mutación , ReproducciónRESUMEN
Aedes aegypti saliva facilitates blood meal acquisition through pharmacologically active compounds that prevent host hemostasis. Among these salivary proteins are the D7s, which are highly abundant and have been shown to act as scavengers of biogenic amines and eicosanoids. In this work, we performed comparative structural modeling, characterized the binding capabilities, and assessed the physiological functions of the Ae. aegypti salivary protein AeD7L2 compared to the well-characterized AeD7L1. AeD7L1 and AeD7L2 show different binding affinities to several biogenic amines and biolipids involved in host hemostasis. Interestingly, AeD7L2 tightly binds U-46619, the stable analog of thromboxane A2 (KD = 69.4 nm), which is an important platelet aggregation mediator, while AeD7L1 shows no binding. We tested the ability of these proteins to interfere with the three branches of hemostasis: vasoconstriction, platelet aggregation, and blood coagulation. Pressure myography experiments showed these two proteins reversed isolated resistance artery vasoconstriction induced by either norepinephrine or U-46619. These proteins also inhibited platelet aggregation induced by low doses of collagen or U-46619. However, D7 long proteins did not affect blood coagulation. The different ligand specificity and affinities of AeD7L1 and AeD7L2 matched our experimental observations from studying their effects on vasoconstriction and platelet aggregation, which confirm their role in preventing host hemostasis. This work highlights the complex yet highly specific biological activities of mosquito salivary proteins and serves as another example of the sophisticated biology underlying arthropod blood feeding.
Asunto(s)
Aedes/metabolismo , Dengue/metabolismo , Proteínas de Insectos/metabolismo , Mosquitos Vectores/metabolismo , Proteínas y Péptidos Salivales/metabolismo , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/metabolismo , Aedes/fisiología , Aedes/virología , Secuencia de Aminoácidos , Animales , Coagulación Sanguínea/fisiología , Dengue/virología , Virus del Dengue/fisiología , Conducta Alimentaria/fisiología , Expresión Génica , Proteínas de Insectos/química , Proteínas de Insectos/genética , Modelos Moleculares , Mosquitos Vectores/virología , Agregación Plaquetaria/fisiología , Unión Proteica , Conformación Proteica , Proteínas y Péptidos Salivales/química , Proteínas y Péptidos Salivales/genética , Homología de Secuencia de AminoácidoRESUMEN
Mosquitoes inject saliva into the host skin to facilitate blood meal acquisition through active compounds that prevent hemostasis. D7 proteins are among the most abundant components of the mosquito saliva and act as scavengers of biogenic amines and eicosanoids. Several members of the D7 family have been characterized at the biochemical level; however, none have been studied thus far in Aedes albopictus, a permissive vector for several arboviruses that causes extensive human morbidity and mortality. Here, we report the binding capabilities of a D7 long form protein from Ae. albopictus (AlboD7L1) by isothermal titration calorimetry and compared its model structure with previously solved D7 structures. The physiological function of AlboD7L1 was demonstrated by ex vivo platelet aggregation and in vivo leukocyte recruitment experiments. AlboD7L1 binds host hemostasis agonists, including biogenic amines, leukotrienes, and the thromboxane A2 analog U-46619. AlboD7L1 protein model predicts binding of biolipids through its N-terminal domain, while the C-terminal domain binds biogenic amines. We demonstrated the biological function of AlboD7L1 as an inhibitor of both platelet aggregation and cell recruitment of neutrophils and eosinophils. Altogether, this study reinforces the physiological relevance of the D7 salivary proteins as anti-hemostatic and anti-inflammatory molecules that help blood feeding in mosquitoes.
Asunto(s)
Aedes/química , Interacciones Huésped-Patógeno/efectos de los fármacos , Inflamación/genética , Proteínas de Insectos/química , Animales , Hemostasis/efectos de los fármacos , Humanos , Inflamación/prevención & control , Proteínas de Insectos/genética , Proteínas de Insectos/farmacología , Leucocitos/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Saliva/química , Proteínas y Péptidos Salivales/química , Proteínas y Péptidos Salivales/farmacologíaRESUMEN
During blood-feeding, mosquito saliva is injected into the skin to facilitate blood meal acquisition. D7 proteins are among the most abundant components of the mosquito saliva. Here we report the ligand binding specificity and physiological relevance of two D7 long proteins from Culex quinquefasciatus mosquito, the vector of filaria parasites or West Nile viruses. CxD7L2 binds biogenic amines and eicosanoids. CxD7L1 exhibits high affinity for ADP and ATP, a binding capacity not reported in any D7. We solve the crystal structure of CxD7L1 in complex with ADP to 1.97 Å resolution. The binding pocket lies between the two protein domains, whereas all known D7s bind ligands either within the N- or the C-terminal domains. We demonstrate that these proteins inhibit hemostasis in ex vivo and in vivo experiments. Our results suggest that the ADP-binding function acquired by CxD7L1 evolved to enhance blood-feeding in mammals, where ADP plays a key role in platelet aggregation.
Asunto(s)
Adenosina Difosfato/química , Culex/química , Mosquitos Vectores , Proteínas y Péptidos Salivales/química , Adenosina Trifosfato/química , Animales , Sitios de Unión , Biología Computacional/métodos , Cristalografía por Rayos X , Eicosanoides/química , Conducta Alimentaria , Perfilación de la Expresión Génica , Hemostasis , Humanos , Proteínas de Insectos/química , Ligandos , Nucleótidos/química , Agregación Plaquetaria , Unión Proteica , Dominios Proteicos , Saliva/química , TermodinámicaRESUMEN
OBJECTIVE: To review evidence behind anticoagulants in cancer-associated venous thromboembolism (VTE) with a focus on low-molecular-weight heparins (LMWH) and the role of direct oral anticoagulants (DOACs). DATA SOURCES: PubMed was searched using terms "venous thromboembolism," "cancer," and "anticoagulation." This search was restricted to clinical trials, meta-analyses, and subgroup analyses. Additional references were identified from reviewing literature citations. STUDY SELECTION: English-language prospective and retrospective studies assessing the efficacy and safety of LMWH and DOACs in patients with cancer. DATA ANALYSIS: Several trials were analyzed that compared anticoagulation therapies for prevention of recurrent VTE in patients with cancer. Many studies comparing LMWH and vitamin K antagonists (VKAs) found nonsignificant differences between therapies. A single study demonstrated that LMWHs are superior to VKAs. This evidence supporting LMWH for long-term VTE treatment in patients with cancer is based on comparison to VKA, but results are limited by methodological issues, and the benefit of LMWH may be driven by poor control. Subanalyses of DOAC trials suggest these are equally or more effective as VKA in cancer, but this conclusion is underpowered. CONCLUSION: DOACs have the potential to bypass many challenges with traditional therapy. After analyzing the evidence available, we conclude that after careful consideration of risks and benefits, use of DOACs for VTE treatment are a reasonable option in patients with cancer.
Asunto(s)
Neoplasias , Anticoagulantes/efectos adversos , Heparina de Bajo-Peso-Molecular/efectos adversos , Humanos , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Estudios Prospectivos , Estudios Retrospectivos , Tromboembolia Venosa/tratamiento farmacológico , Tromboembolia Venosa/prevención & control , Vitamina KRESUMEN
OBJECTIVE: To decrease the number of orders and total hospital spend for inpatient use of antineoplastic drugs of interest, while evaluating each case for urgent or emergent need for administration. METHODOLOGY: This study is a multicenter, retrospective, cost-evaluation, cohort study performed in five Ascension Seton hospitals in the Austin, Texas area between 1 January 2013 and 31 December 2018. Patients were identified via a dispense analysis report for the antineoplastic drugs of interest. RESULTS: An overall reduction of 56% was seen in orders processed with a 62% decrease in annual hospital spending after implementation of the criteria-for-use algorithm. When results were evaluated without including rituximab orders, a reduction of 17% was seen in orders processed with a 21% decrease in annual hospital spending. DISCUSSION AND CONCLUSION: The decreases in our primary outcomes were primarily driven by a reduction in the use of one drug, rituximab. Overall, implementation of a criteria-for-use algorithm was effective in reducing both overall number of orders and hospital spending for restricted antineoplastic agents.
Asunto(s)
Algoritmos , Antineoplásicos/uso terapéutico , Anciano , Femenino , Formularios de Hospitales como Asunto , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Estudios RetrospectivosRESUMEN
Aedes aegypti thrives in urban environments and transmits several debilitating human viral diseases. Thus, our ability to control this mosquito species in endemic areas is of utmost importance. The use of insecticides, mostly pyrethroids and organophosphates (OPs), has long been the primary means of controlling A. aegypti, but widespread insecticide resistance has emerged. The two main mechanisms of pyrethroid resistance in A. aegypti are CYP-mediated detoxification and mutations in the target site, voltage-sensitive sodium channel (Vssc), referred to as knockdown resistance (kdr). Knowledge about the contributions and interactions of these mechanisms to resistance is important for the understanding of the molecular and evolutionary basis of insecticide resistance, and to determine the effectiveness of insecticides. In this study, we address two aims: 1) determine the patterns of CYP-mediated cross-resistance to pyrethroid and OP insecticides, both in the presence and absence of kdr (S989Pâ¯+â¯V1016G), and 2) determine whether the interaction between the two mechanisms yields a greater than, less than, or additive effect on resistance. We tested seven pyrethroids and four OPs against three congenic strains of A. aegypti: ROCK (susceptible), CYP:ROCK (CR) (resistant due to CYP-mediated detoxification without kdr), and CYPâ¯+â¯KDR:ROCK (CKR) (resistant due to both CYPs and kdr), and compared these to the congenic KDR:ROCK strain that was previously reported. We found that resistance ratios (RRs) were variable between pyrethroids and strains, ranging from 6.2- to 42-fold for CR, and 70- to 261-fold for CKR. In general, we found that CYP-mediated resistance alone contributes less to resistance than kdr. The effect of the combined mechanisms on resistance was significantly greater than additive for all pyrethroids except (1R)-trans-fenfluthrin. CYP-mediated pyrethroid resistance conferred cross-resistance to both methyl paraoxon and fenitrothion, and negative cross-resistance to methyl parathion and naled. Based on our results, we recommend that etofenprox and cyfluthrin be avoided for A. aegypti control in areas where these two resistance mechanisms are prevalent.
Asunto(s)
Aedes/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/metabolismo , Organofosfatos/farmacología , Piretrinas/farmacología , Animales , Femenino , Técnicas de Silenciamiento del Gen , Resistencia a los Insecticidas/genética , Masculino , MutaciónRESUMEN
Aedes aegypti poses a serious risk to human health due to its wide global distribution, high vector competence for several arboviruses, frequent human biting, and ability to thrive in urban environments. Pyrethroid insecticides remain the primary means of controlling adult A. aegypti populations during disease outbreaks. As a result of decades of use, pyrethroid resistance is a global problem. Cytochrome P450 monooxygenase (CYP)-mediated detoxification is one of the primary mechanisms of pyrethroid resistance. However, the specific CYP(s) responsible for resistance have not been unequivocally determined. We introgressed the resistance alleles from the resistant A. aegypti strain, Singapore (SP), into the genetic background of the susceptible ROCK strain. The resulting strain (CKR) was congenic to ROCK. Our primary goal was to determine which CYPs in SP are linked to resistance. To do this, we first determined which CYPs overexpressed in SP are also overexpressed in CKR, with the assumption that only the CYPs linked to resistance will be overexpressed in CKR relative to ROCK. Next, we determined whether any of the overexpressed CYPs were genetically linked to resistance (cis-regulated) or not (trans-regulated). We found that CYP6BB2, CYP6Z8, CYP9M5 and CYP9M6 were overexpressed in SP as well as in CKR. Based on the genomic sequences and polymorphisms of five single copy CYPs (CYP4C50, 6BB2, 6F2, 6F3 and 6Z8) in each strain, none of these genes were linked to resistance, except for CYP6BB2, which was partially linked to the resistance locus. Hence, overexpression of these four CYPs is due to a trans-regulatory factor(s). Knowledge on the specific CYPs and their regulators involved in resistance is critical for resistance management strategies because it aids in the development of new control chemicals, provides information on potential environmental modulators of resistance, and allows for the detection of resistance markers before resistance becomes fixed in the population.
Asunto(s)
Aedes/efectos de los fármacos , Aedes/enzimología , Sistema Enzimático del Citocromo P-450/metabolismo , Proteínas de Insectos/metabolismo , Resistencia a los Insecticidas , Insecticidas/toxicidad , Permetrina/toxicidad , Aedes/genética , Alelos , Animales , Sistema Enzimático del Citocromo P-450/genética , Femenino , Proteínas de Insectos/genética , Insecticidas/metabolismo , Masculino , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/enzimología , Mosquitos Vectores/genética , Permetrina/metabolismo , Polimorfismo de Nucleótido Simple , SingapurRESUMEN
BACKGROUND: Aedes aegypti is a vector of several important human pathogens. Control efforts rely primarily on pyrethroid insecticides for adult mosquito control, especially during disease outbreaks. A. aegypti has developed resistance nearly everywhere it occurs and insecticides are used. An important mechanism of resistance is due to mutations in the voltage-sensitive sodium channel (Vssc) gene. Two mutations, in particular, S989P + V1016G, commonly occur together in parts of Asia. RESULTS: We have created a strain (KDR:ROCK) that contains the Vssc mutations S989P + V1016G as the only mechanism of pyrethroid resistance within the genetic background of Rockefeller (ROCK), a susceptible lab strain. We created KDR:ROCK by crossing the pyrethroid-resistant strain Singapore with ROCK followed by four backcrosses with ROCK and Vssc S989P + V1016G genotype selections. We determined the levels of resistance conferred to 17 structurally diverse pyrethroids, the organochloride DDT, and oxadiazines (VSSC blockers) indoxacarb (proinsecticide) and DCJW (the active metabolite of indoxacarb). Levels of resistance to the pyrethroids were variable, ranging from 21- to 107-fold, but no clear pattern between resistance and chemical structure was observed. Resistance is inherited as an incompletely recessive trait. KDR:ROCK had a > 2000-fold resistance to DDT, 37.5-fold cross-resistance to indoxacarb and 13.4-fold cross-resistance to DCJW. CONCLUSION: Etofenprox (and DDT) should be avoided in areas where Vssc mutations S989P + V1016G exist at high frequencies. We found that pyrethroid structure cannot be used to predict the level of resistance conferred by kdr. These results provide useful information for resistance management and for better understanding pyrethroid interactions with VSSC. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Aedes/efectos de los fármacos , Aedes/genética , Proteínas de Insectos/genética , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Canales de Sodio Activados por Voltaje/genética , Animales , DDT/farmacología , Proteínas de Insectos/metabolismo , Mutación , Oxazinas/farmacología , Piretrinas/farmacología , Canales de Sodio Activados por Voltaje/metabolismoRESUMEN
The programmed-death-1 inhibitors selectively block programmed-death-1 interaction with its receptor, which restores active T-cell response directed at tumor cells, inducing an anti-tumor effect. This nonspecific activation of the immune system can also lead to a wide spectrum of side effects. Nivolumab has been used effectively to prolong survival in patients with metastatic melanoma and is recommended as a category 1 agent for systemic therapy in metastatic or unresectable melanoma per the National Comprehensive Cancer Network guidelines. We present a case of a 64-year-old woman who began nivolumab therapy for metastatic melanoma. After six doses of nivolumab therapy, the patient experienced generalized hypopigmentation on her face, chest, back, arms, and lower extremities. Although vitiligo has been reported in as many as 10.7% of patients undergoing nivolumab therapy in some clinical trials, we believe this is the first case to describe the progression of nivolumab-induced vitiligo in a metastatic melanoma patient. This case provides significant insight into the onset, symptoms, development, and treatment options for patients experiencing vitiligo as a result of nivolumab therapy.
Asunto(s)
Anticuerpos Monoclonales/efectos adversos , Antineoplásicos/efectos adversos , Melanoma/tratamiento farmacológico , Neoplasias Cutáneas/tratamiento farmacológico , Vitíligo/inducido químicamente , Vitíligo/diagnóstico , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Femenino , Humanos , Melanoma/diagnóstico , Persona de Mediana Edad , Nivolumab , Neoplasias Cutáneas/diagnósticoRESUMEN
Aedes aegypti and A. albopictus mosquitoes are vectors of important human disease viruses, including dengue, yellow fever, chikungunya and Zika. Pyrethroid insecticides are widely used to control adult Aedes mosquitoes, especially during disease outbreaks. Herein, we review the status of pyrethroid resistance in A. aegypti and A. albopictus, mechanisms of resistance, fitness costs associated with resistance alleles and provide suggestions for future research. The widespread use of pyrethroids has given rise to many populations with varying levels of resistance worldwide, albeit with substantial geographical variation. In adult A. aegypti and A. albopictus, resistance levels are generally lower in Asia, Africa and the USA, and higher in Latin America, although there are exceptions. Susceptible populations still exist in several areas of the world, particularly in Asia and South America. Resistance to pyrethroids in larvae is also geographically widespread. The two major mechanisms of pyrethroid resistance are increased detoxification due to P450-monooxygenases, and mutations in the voltage sensitive sodium channel (Vssc) gene. Several P450s have been putatively associated with insecticide resistance, but the specific P450s involved are not fully elucidated. Pyrethroid resistance can be due to single mutations or combinations of mutations in Vssc. The presence of multiple Vssc mutations can lead to extremely high levels of resistance. Suggestions for future research needs are presented.
Asunto(s)
Aedes/efectos de los fármacos , Resistencia a los Insecticidas , Insecticidas/farmacología , Mosquitos Vectores/efectos de los fármacos , Piretrinas/farmacología , Aedes/genética , Animales , Sistema Enzimático del Citocromo P-450/genética , Humanos , Resistencia a los Insecticidas/genética , Mosquitos Vectores/genética , Canales de Sodio Activados por Voltaje/genéticaRESUMEN
During the fall of 2010, 332 deer serum samples were collected from 15 of the 16 (93.8%) Maine counties and screened for eastern equine encephalitis virus (EEEV) antibodies using plaque reduction neutralizing tests (PRNTs). The aim was to detect and map EEEV activity in the state of Maine. Forty-seven of the 332 (14.2%) sera were positive for EEEV antibodies, showing a much wider distribution of EEEV activity in Maine than previously known. The percentage of EEEV antibody-positive deer sera was ≥10% in six counties-Piscataquis (100%), Somerset (28.6%), Waldo (22.2%), Penobscot (21.7%), Kennebec (13.7%), and Sagadahoc (10%). Positive sera were detected in all the six counties (Somerset, Waldo, Penobscot, Kennebec, Cumberland, and York) that were positive in 2009, suggesting endemic EEEV activity in these counties. EEEV antibodies were not detected in sera collected in five counties-Franklin, Knox, Lincoln, Oxford, and Washington-which was either due to low sample size or lack of EEEV activity in these counties. Our data suggest higher EEEV activity in central Maine compared to southern Maine, whereas EEEV activity in Maine has historically been associated with the southern counties of York and Cumberland.
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Ciervos/sangre , Virus de la Encefalitis Equina del Este/fisiología , Encefalomielitis Equina/veterinaria , Animales , Encefalomielitis Equina/epidemiología , Encefalomielitis Equina/inmunología , Encefalomielitis Equina/virología , Maine/epidemiología , Estudios SeroepidemiológicosRESUMEN
Moose sera were collected from harvested animals during the 2010 hunting season in Maine. Of the 145 serum samples screened by plaque reduction neutralization test (PRNT), 16 (11%) had antibodies to eastern equine encephalitis virus (EEEV). Positive samples were collected from Aroostook County (n=13), Somerset County (n=2), and Piscataquis County (n=1) in northern and central Maine. Preliminary mosquito surveillance revealed the presence of enzootic and bridge vectors mosquitoes, including Culiseta (Climacura) melanura (Coquillett), Aedes (Aedimorphus) vexans (Meigen), and Coquillettidia (Coquillettidia) perturbans (Walker). Select mosquito species were tested by RT-PCR for the presence of EEEV. None were positive. This is the first report of EEEV in moose from Maine.
Asunto(s)
Anticuerpos Antivirales/sangre , Culicidae/virología , Ciervos/virología , Virus de la Encefalitis Equina del Este/inmunología , Encefalomielitis Equina/veterinaria , Insectos Vectores/virología , Animales , Virus de la Encefalitis Equina del Este/aislamiento & purificación , Encefalomielitis Equina/epidemiología , Encefalomielitis Equina/virología , Femenino , Maine/epidemiología , Masculino , Pruebas de Neutralización/veterinaria , Vigilancia de la Población , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinariaRESUMEN
OBJECTIVE: The objectives of this article are to review the clinical implications of drug shortages highlighting patient safety, sedation, and oncology and introduce an expanded phase approach for the management of drug shortages. DATA SOURCES: Literature retrieval was accessed through a PubMed search of English-language sources from January 1990 through April 2012 using the medical subject heading pharmaceutical preparations/supply and distribution and the general search term drug shortages. STUDY SELECTION AND DATA EXTRACTION: All original prospective and retrospective studies, peer-reviewed guidelines, consensus statements, and review articles were evaluated for inclusion. Relevance was determined considering the therapeutic class, focus on drug shortages, and manuscript type. DATA SYNTHESIS: The increased number of drug shortages has created significant challenges for health care providers. Two particularly vulnerable populations are critically ill and oncology patients. A lack of therapeutic alternatives in critically ill patients may impact patient safety as well as treatment outcomes. Similarly, a chemotherapy agent in short supply may contribute to adverse outcomes in oncology patients. CONCLUSIONS: The mounting number of drug shortages has created a health care crisis, requiring changes in management strategies as well as clinical practice. The expanded phased approach outlined here provides a consistent, systematic approach for the management of drug shortages.