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1.
J Med Entomol ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38747350

RESUMO

Culex pipiens pallens Coquillett, 1898 (Diptera: Culicidae) was the dominant health threat to mosquito species in Beijing, and it is important to unravel the spatial distribution and environmental correlations of Cx. pipiens pallens in Beijing. 3S technology methods and spatial statistics were used to clarify the distribution pattern. Subsequently, linear and spatial regression were performed to detect the environmental factors linked with the density of Cx. pipiens pallens. The same "middle peak" spatial distribution pattern was observed for Cx. pipiens pallens density at the community, subdistrict, and loop area levels in our study area. In addition, there were various correlated environmental factors at the community and subdistrict scales. At the community scale, the summary values of the Modified Normalized Difference Water Index (MNDWI) in 2 km buffer zone (MNDWI_2K) were negatively correlated, and the summary values of Normalized Difference Built-up Index (NDBI) in 800 m buffer zone (NDBI_800) was positively correlated to the Cx. pipiens pallens density. However, the summary values of Normalized Difference Vegetation Index and Nighttime Light Index significantly affected Cx. pipiens pallens density at the subdistrict scale. Our findings provide insight into the spatial distribution pattern of Cx. pipiens pallens density and its associated environmental risk factors at different spatial scales in the Haidian district of Beijing for the first time. The results could be used to predict the Cx. pipiens pallens density as well as the risk of lymphatic filariasis (LF) infection, which would help implement prevention and control measures to prevent future risks of biting and LF transmission in Beijing.

2.
Mar Pollut Bull ; 183: 114056, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36058179

RESUMO

Most previous studies investigating the interplay of ocean acidification (OA) and heavy metal on marine phytoplankton were only conducted in short-term, which may provide conservative estimates of the adaptive capacity of them. Here, we examined the physiological responses of long-term (~900 generations) OA-adapted and non-adapted populations of the diatom Phaeodactylum tricornutum to different concentrations of the two heavy metals Cd and Cu. Our results showed that long-term OA selected populations exhibited significantly lower growth and reduced photosynthetic activity than ambient CO2 selected populations at relatively high heavy metal levels. Those findings suggest that the adaptations to high CO2 results in an increased sensitivity of the marine diatom to toxic metal exposure. This study provides evidence for the costs and the cascading consequences associated with the adaptation of phytoplankton to elevated CO2 conditions, and improves our understanding of the complex interactions of future OA and heavy metal pollution in marine waters.


Assuntos
Diatomáceas , Metais Pesados , Cádmio/toxicidade , Dióxido de Carbono , Concentração de Íons de Hidrogênio , Metais Pesados/toxicidade , Oceanos e Mares , Fitoplâncton/fisiologia , Água do Mar
3.
Oxid Med Cell Longev ; 2022: 4845264, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35281464

RESUMO

Background: The continuous development of endovascular treatment technology provides more opportunities for the histological study of thrombus. According to Trial of Org 10 172 in Acute Stroke Treatment (TOAST), clinicians take different strategies in anticoagulant or antiplatelet therapy. There are some patients still suffering from recurrent stroke while they took anticoagulant or antiplatelet drugs regularly for secondary prevention. In view of that, we found that histological analysis of thrombus can provide guidance for secondary prevention. Aim: Exploring the histological characteristics differences between large atherosclerotic and cardiogenic embolic thrombosis in order to guide clinical secondary prevention of the two stroke subtypes. Methods: A total of 54 patients with acute ischemic stroke were collected from December 2019 to April 2021. Identify stroke subtypes according to TOAST classification. Stain thrombus specimens with hematoxylin-eosin staining, and perform statistical analysis on the components (red blood cells and fibrin/platelets) of thrombus. Results: In cardiogenic thrombi, the composition of RBCs was dominant (51.38 ± 18.463%) compared to that of fibrin/platelets (48.62 ± 18.463%). Similarly, among the thrombi of large artery atherosclerotic, RBCs (50.40 ± 20.100%) compared to fibrin/platelets (49.60 ± 20.100%). There was no statistical difference in RBCs or fibrin/platelet composition of both cardiogenic and atherosclerotic thrombi (P = 0.89). Conclusions: The histologic composition of thrombi in cardiogenic and atherosclerotic had no statistical difference. These thrombi are all mixed thrombus, which are rich in RBCs, fibrinogen, and platelets. Anticoagulation combined with antiplatelet may be a more effective secondary prevention strategy.


Assuntos
Aterosclerose/patologia , Trombose/patologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
Front Immunol ; 13: 766099, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35185873

RESUMO

Objectives: This study sought to explore the expression patterns of repulsive guidance molecules a (RGMa) in neuromyelitis optica spectrum disorders (NMOSD) and to explore the correlation between RGMa and the clinical features of NMOSD. Methods: A total of 83 NMOSD patients and 22 age-matched healthy controls (HCs) were enrolled in the study from October 2017 to November 2021. Clinical parameters, including Expanded Disability Status Scale (EDSS) score, degree of MRI enhancement, and AQP4 titer were collected. The expression of serum RGMa was measured by enzyme-linked immunosorbent assay (ELISA) and compared across the four patient groups. The correlation between serum RGMa levels and different clinical parameters was also assessed. Results: The average serum expression of RGMa in the NMOSD group was significantly higher than that in the HC group (p < 0.001). Among the patient groups, the acute phase group exhibited significantly higher serum RGMa levels than did the remission group (p < 0.001). A multivariate analysis revealed a significant positive correlation between RGMa expression and EDSS score at admission, degree of MRI enhancement, and segmental length of spinal cord lesions. There was a significant negative correlation between the expression of RGMa in NMOSD and the time from attack to sampling or delta EDSS. Conclusions: The current study suggests that RGMa may be considered a potential biomarker predicting the severity, disability, and clinical features of NMOSD.


Assuntos
Aquaporina 4/imunologia , Proteínas Ligadas por GPI/sangue , Proteínas do Tecido Nervoso/sangue , Neuromielite Óptica/patologia , Medula Espinal/diagnóstico por imagem , Adulto , Autoanticorpos/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Avaliação da Deficiência , Feminino , Humanos , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Neuromielite Óptica/sangue , Neuromielite Óptica/diagnóstico por imagem , Índice de Gravidade de Doença , Medula Espinal/patologia , Adulto Jovem
5.
Biomed Res Int ; 2021: 5532116, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33997000

RESUMO

Repulsive guidance molecule-a (RGMa) is a member of glycosylphosphatidylinositol- (GPI-) anchored protein family, which has axon guidance function and is widely involved in the development and pathological processes of the central nervous system (CNS). On the one hand, the binding of RGMa and its receptor Neogenin can regulate axonal guidance, differentiation of neural stem cells into neurons, and the survival of these cells; on the other hand, RGMa can inhibit functional recovery of CNS by inhibiting axonal growth. A number of studies have shown that RGMa may be involved in the pathogenesis of CNS diseases, such as multiple sclerosis, neuromyelitis optica spectrum diseases, cerebral infarction, spinal cord injury, Parkinson's disease, and epilepsy. Targeting RGMa can enhance the functional recovery of CNS, so it may become a promising target for the treatment of CNS diseases. This article will comprehensively review the research progression of RGMa in various CNS diseases up to date.


Assuntos
Doenças do Sistema Nervoso Central/metabolismo , Doenças do Sistema Nervoso Central/patologia , Proteínas Ligadas por GPI/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Pesquisa Biomédica , Proliferação de Células/fisiologia , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Neurogênese/fisiologia , Ratos , Transdução de Sinais/fisiologia
6.
Front Chem ; 8: 781, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33195022

RESUMO

Lithium-boron (Li-B) alloys play an important role in the fields of thermal batteries and Li metal batteries, where the electrochemical performance is highly dependent on microstructure homogeneity and the Li content. In this study, computed tomography (CT) scanning has been firstly used to study the elemental content and spatial distribution of Li in a Li-B alloy. For a commercial Li-B alloy, quantitative relationships between the CT values, [Hu], and the weight percent of Li, w T-Li, and the density, ρLi-B, that is, [Hu] = 13563 . 8 36 . 2 × w T - Li - 2 . 8 - 1 , 016 . 2 and [Hu] = 790.1 × ρLi-B - 1, 016.2, respectively. The experimental data were found to be in good agreement with current theory. The CT scanning method was non-destructive, and proved to be fast, highly accurate, and low-cost for the characterization of Li-B alloy ingots in terms of elemental composition, density, and uniformity.

7.
Sci Rep ; 10(1): 8400, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32439946

RESUMO

Two unique housefly strains, PSS and N-PRS (near-isogenic line with the PSS), were used to clarify the mechanisms associated with propoxur resistance in the housefly, Musca domestica. The propoxur-selected resistant (N-PRS) strain exhibited >1035-fold resistance to propoxur and 1.70-, 12.06-, 4.28-, 57.76-, and 57.54-fold cross-resistance to beta-cypermethrin, deltamethrin, bifenthrin, phoxim, and azamethiphos, respectively, compared to the susceptible (PSS) strain. We purified acetylcholinesterase (AChE) from the N-PRS and PSS strains using a procainamide affinity column and characterized the AChE. The sensitivity of AChE to propoxur based on the bimolecular rate constant (Ki) was approximately 100-fold higher in the PSS strain compared to the N-PRS strain. The cDNA encoding Mdace from both the N-PRS strain and the PSS strain were cloned and sequenced using RT-PCR. The cDNA was 2073 nucleotides long and encoded a protein of 691 amino acids. A total of four single nucleotide polymorphisms (SNPs), I162M, V260L, G342A, and F407Y, were present in the region of the active site of AChE from the N-PRS strain. The transcription level and DNA copy number of Mdace were significantly higher in the resistant strain than in the susceptible strain. These results indicated that mutations combined with the up-regulation of Mdace might be essential in the housefly resistance to propoxur.


Assuntos
Acetilcolinesterase/genética , Moscas Domésticas/efeitos dos fármacos , Proteínas de Insetos/genética , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/farmacologia , Propoxur/farmacologia , Acetilcolinesterase/metabolismo , Animais , Inibidores da Colinesterase/farmacologia , Regulação Enzimológica da Expressão Gênica , Moscas Domésticas/genética , Proteínas de Insetos/metabolismo , Resistência a Inseticidas/genética , Mutação , Polimorfismo de Nucleotídeo Único
8.
Mar Environ Res ; 154: 104871, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31928985

RESUMO

In this study, we examined the effects of increased temperature (15, 20 and 25 °C) and different light levels (50, 200 µmol photons m-2 s-1) on two widely distributed diatoms, namely Phaeodactylum tricornutum and Thalassiosira weissflogii. Results showed that increasing light level counteracted the negative effects of high temperature on photosynthesis in both species, suggesting an antagonistic interaction between light and temperature. Contrary to the above results, light limitation diminished the temperature-sensitivity of carbonic anhydrase activity in two diatoms. We also observed species-specific responses of biomass, where increased temperature significantly decreased the biomass of P. tricornutum at both low and high light levels but showed no effects on T. weissflogii. Our study demonstrated that light can alter the physiological responses of diatoms to temperature but also revealed interspecific variations. We predict that in the future ocean with shallower upper mixed layer, T. weissflogii may be more competitive than P. tricornutum.


Assuntos
Diatomáceas , Biomassa , Luz , Fotossíntese , Especificidade da Espécie , Temperatura
9.
Pest Manag Sci ; 76(1): 405-414, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31381253

RESUMO

BACKGROUND: Stable flies are one of the most detrimental arthropod pests to livestock. With changing climates and agronomic practices, they expand their roles as pests and disease vectors as well. Their painful bites reduce livestock productivity, annoy companion animals, and interfere with human recreational activities. Current management technologies are unable to effectively control stable flies. The present study reports new results concerning the contact, spatial repellency, and toxicity of a bio-based product, coconut fatty acid and their methyl ester derivatives of free fatty acids of C8:0 , C10:0 and C12:0 to stable flies. RESULTS: Three medium chain fatty acid methyl esters (C8:0 , C10:0 and C12:0 ) showed strong antifeedant activity against stable flies and their strengths were dose-dependent. Only the C8:0 acid, C8:0 - and C10:0 methyl esters elicited significant antennal responses. Laboratory single cage olfactometer bioassays revealed that coconut fatty acid and C8:0 methyl ester displayed active spatial repellency. All three methyl esters showed strong toxicity against stable flies. CONCLUSION: Antifeedant activity is the main method through which coconut fatty acid deters stable fly blood-feeding. The C8:0 , C10:0 and C12:0 methyl esters act not only as strong antifeedants, but also possess strong toxicity against stable fly adults. Limited spatial repellency was observed from coconut fatty acid and C8:0 methyl ester. © 2019 Society of Chemical Industry.


Assuntos
Muscidae , Envelhecimento , Animais , Cocos , Ésteres , Ácidos Graxos , Repelentes de Insetos
10.
Parasit Vectors ; 12(1): 180, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-31014392

RESUMO

BACKGROUND: Aedes albopictus (Skuse) is an important vector of chikungunya, dengue, yellow fever and Zika viruses. In the absence of anti-viral medication and with limited availability of a commercial vaccine for public health use, vector control remains an effective means for reducing Aedes-borne disease morbidity. Knowledge about genetic mutations associated with insecticide resistance (IR) is a prerequisite for developing rapid resistance diagnosis, and the distribution and frequency of IR conferring mutations is important information for making smart vector control decisions. METHODS: Partial DNA sequences of domain II and domain III of Ae. albopictus voltage gated sodium channel (VGSC) gene were amplified from a total of 426 individuals, collected from 17 sites in the Beijing municipality. These DNA fragments were sequenced to discover the possible genetic mutations mediating knockdown resistance (kdr) to pyrethroids. The frequency and distribution of kdr mutations were assessed in the 17 Ae. albopictus populations. The origin of kdr mutations was investigated by haplotype clarification and phylogenetic analysis. RESULTS: Sequence alignments revealed the existence of multiple mutations (V1016G, I1532T, F1534S and F1534L) in VGSC. The highest frequency of the mutant 1016G allele (0.647) was found in Haidian, while 1016G was not detected in Huai Rou, Yan Qing, Ping Gu and Shun Yi. The frequency of 1532T was highest (0.537) in the population from the Olympic Forest Park (OFP, Chao Yang District), but not detectable in Huai Rou and Mi Yun. Two mutations were observed at codon 1534 with different distribution patterns: 1534L was only found in Tong Zhou (TZ) with a frequency of 0.017, while 1534S was distributed in TZ, OFP, Fang Shan, Da Xing and Shi Jing Shan with frequencies ranging from 0.019 (OFP) to 0.276 (TZ). One 1016G, one 1532T, one 1534L and two 1534S haplotypes were identified. CONCLUSIONS: Multiple mutations (V1016G, I1532T, F1534L/S) in VGSC were found in Ae. albopictus in Beijing. This represents the first report of V1016G in Ae. albopictus. Sequence alignment and phylogenetic analysis revealed multiple origins of 1534S. The spatial heterogeneity in distribution and frequency of kdr mutations calls for a site-specific strategy for the monitoring of insecticide resistance. The relatively high frequencies of V1016G warn of a risk of pyrethroid resistance in mosquitoes in the urban zones.


Assuntos
Aedes/genética , Resistência a Inseticidas/genética , Mosquitos Vetores/genética , Mutação , Canais de Sódio Disparados por Voltagem/genética , Aedes/efeitos dos fármacos , Alelos , Animais , Pequim , Análise Mutacional de DNA , Evolução Molecular , Genes de Insetos , Haplótipos , Mosquitos Vetores/efeitos dos fármacos , Filogenia , Polimorfismo Genético , Análise de Sequência de DNA
11.
Environ Sci Pollut Res Int ; 26(16): 16388-16395, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30982194

RESUMO

Diatoms are experiencing striking fluctuations in seawater carbonate chemistry in the natural marine environment, especially in coastal seawaters. Here, we show that the diatoms Thalassiosira weissflogii and Phaeodactylum tricornutum, which utilize different carbon acquisition mechanisms, respond differently to short-term changes in seawater carbonate chemistry. Our results showed that T. weissflogii showed significantly higher photosynthetic oxygen evolution rates than that of P. tricornutum at low levels of CO2 or HCO3-. This suggests that T. weissflogii had higher affinities for CO2 or HCO3- when their concentrations were not sufficient to support saturated growth and photosynthesis. While the activity of Rubisco in P. tricornutum positively correlated with carbonic anhydrases (CA), we observed negative relationship between Rubisco and CA activity in the diatom T. weissflogii. These contrasting physiological responses of diatoms with varied carbon acquisition mechanisms indicate different abilities to cope up with abrupt changes in seawater carbonate chemistry. We propose that the ability to respond to varying carbonate chemistry may act as one determinant of the diatom distributions and phytoplankton community structures.


Assuntos
Dióxido de Carbono , Anidrases Carbônicas/metabolismo , Diatomáceas/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Água do Mar/química , Carbono/metabolismo , Diatomáceas/crescimento & desenvolvimento , Diatomáceas/fisiologia , Fotossíntese/fisiologia , Fitoplâncton/metabolismo , Especificidade da Espécie
12.
Mar Environ Res ; 133: 15-23, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29174425

RESUMO

A classical red tide alga Skeletonema costatum was cultured under various nitrate levels to investigate its physiological response to nitrate enrichment combined with CO2 limitation. The higher nitrate levels increased content of photosynthetic pigments (Chl a and Chl c), electron transport rate in photosystem II, photosynthetic O2 evolution, and thus growth rate in S. costatum. On the other hand, the lower CO2 levels (3.5-4.4 µmol kg-1 seawater) and higher pH (8.56-8.63) values in seawater were observed under higher nitrate conditions. Redox activity of plasma membrane and carbonic anhydrase in S. costatum was enhanced to address the reduced CO2 level at higher nitrate levels. In addition, the pH compensation point was enhanced and direct HCO3- use was induced at higher nitrate levels. These findings indicate that nitrate enrichment would stimulate the breakout of S. costatum dominated red tides via enhancing its photosynthetic performances, and maintain a quick growth rate under CO2 limitation conditions through improving its inorganic carbon acquisition capability. Our study sheds light on the mechanisms of S. costatum defeating CO2 limitation during algal bloom.


Assuntos
Diatomáceas/fisiologia , Proliferação Nociva de Algas , Nitratos/metabolismo , Poluentes Químicos da Água/metabolismo , Carbono , Fotossíntese
13.
Econ Hum Biol ; 21: 210-20, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26975006

RESUMO

OBJECTIVES: To analyze the growth trends of children in Beijing from 1955 to 2010. METHODS: Data for the period 1955-1975 were derived from published records. Data for the period 1985-2010 were derived from the Chinese National Survey on Students' Constitution and Health (CNSSCH). Since 1985, the overall sampling and measurement methods have been consistent. The mean, the standard deviation, and the variance (ANOVA) of height, weight, and BMI by age and sex of students aged 7-17 were calculated and analyzed. RESULTS: Between 1955 and 2010, the average height and weight of children in Beijing has increased. The average increments per decade for boys and girls were 2.45cm and 2.03cm in height and 2.68kg and 1.68kg in weight, respectively. The largest height increase per decade occurred between 1975 and 1985: 4.51cm and 3.23cm for boys and girls, respectively. The largest height increase for the entire 55-year period under study occurred among boys at age 13 (17.85cm) and among girls at age 11 (15.90cm.) CONCLUSIONS: During the period 1955-2010, growth trends among children in Beijing were positive. The health and nutritional status of these children improved significantly. Since 2007, might be related to government intervention, childhood obesity has been curbed.


Assuntos
Estatura/fisiologia , Peso Corporal/fisiologia , Desenvolvimento Infantil/fisiologia , Adolescente , Fatores Etários , Pequim/epidemiologia , Índice de Massa Corporal , Criança , Feminino , Humanos , Masculino , Fatores Sexuais , Fatores Socioeconômicos
14.
PLoS One ; 9(9): e106932, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25265537

RESUMO

BACKGROUND: The German cockroach, Blattella germanica, is an important insect pest that transmits various pathogens mechanically and causes severe allergic diseases. This insect has long served as a model system for studies of insect biology, physiology and ecology. However, the lack of genome or transcriptome information heavily hinder our further understanding about the German cockroach in every aspect at a molecular level and on a genome-wide scale. To explore the transcriptome and identify unique sequences of interest, we subjected the B. germanica transcriptome to massively parallel pyrosequencing and generated the first reference transcriptome for B. germanica. METHODOLOGY/PRINCIPAL FINDINGS: A total of 1,365,609 raw reads with an average length of 529 bp were generated via pyrosequencing the mixed cDNA library from different life stages of German cockroach including maturing oothecae, nymphs, adult females and males. The raw reads were de novo assembled to 48,800 contigs and 3,961 singletons with high-quality unique sequences. These sequences were annotated and classified functionally in terms of BLAST, GO and KEGG, and the genes putatively coding detoxification enzyme systems, insecticide targets, key components in systematic RNA interference, immunity and chemoreception pathways were identified. A total of 3,601 SSRs (Simple Sequence Repeats) loci were also predicted. CONCLUSIONS/SIGNIFICANCE: The whole transcriptome pyrosequencing data from this study provides a usable genetic resource for future identification of potential functional genes involved in various biological processes.


Assuntos
Baratas/genética , Transcriptoma , Sequência de Aminoácidos , Animais , DNA Complementar/genética , Etiquetas de Sequências Expressas , Imunidade Inata/genética , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Interferência de RNA , RNA Mensageiro/genética , Homologia de Sequência de Aminoácidos
15.
J Econ Entomol ; 106(2): 979-87, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23786090

RESUMO

A commercial vinegar product (ChinKiang) was found to be highly attractive to adult house flies, Musca domestica L. Field experiments on a Nebraska dairy demonstrated that traps baited with vinegar and brown sugar captured more house flies than those baited with other house fly attractants. Solid phase microextraction was used in the field to collect volatiles from the vinegar bait. Seven compounds were identified as, acetic acid, furfural, butanoic acid, isovaleric acid, hexanoic acid, 2-phenylethanol, and p-cresol. Electroantennograms showed that the seven vinegar components elicited significant responses from antennae of female and male house flies. Bioassays indicated that the vinegar blend of the seven volatile components were more attractive than any of the individual components. Field evaluations demonstrated that traps baited with the synthetic seven component blend caught as many flies as those baited with vinegar. This is the first detailed report of house fly attractants from vinegar. The vinegar volatile compounds identified in this study will be useful for the development of less objectionable alternatives to the fetid, manure mimicking volatiles currently used in commercial fly bait systems, especially those designed for use in indoor environments.


Assuntos
Ácido Acético/farmacologia , Moscas Domésticas/efeitos dos fármacos , Controle de Insetos/métodos , Feromônios/farmacologia , Compostos Orgânicos Voláteis/farmacologia , Animais , Indústria de Laticínios , Feminino , Masculino , Nebraska , Microextração em Fase Sólida
16.
J Am Mosq Control Assoc ; 24(1): 161-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18437833

RESUMO

The larvicidal activity of 4 plant essential oils--innamon oil, lemon eucalyptus oil, sandalwood oil, and turmeric oil--previously reported as insect repellents was evaluated in the laboratory against 4th instars of Aedes albopictus, Ae. aegypti, and Culex pipiens. Sandalwood oil appeared to be the most effective of the larvicides, killing larvae of all 3 mosquito species in relatively short times. The values of LT50 and LT90 at the application dosage (0.2 mg/ml) were 1.06 +/- 0.11 and 3.24 +/- 0.14 h for Ae. aegypti, 1.82 +/- 0.06 and 3.33 +/- 0.48 h for Ae. albopictus, and 1.55 +/- 0.07 and 3.91 +/- 0.44 h for Cx. pipiens, respectively. Chemical compositions of these essential oils were also studied, and the lavicidal activity of their major ingredient compounds was compared with that of each of the essential oils. The acute toxicity of the 4 essential oils to fathead minnows was also evaluated. The safe use of these natural plant essential oils in future applications of mosquito control was discussed.


Assuntos
Culicidae/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Inseticidas/farmacologia , Óleos de Plantas/farmacologia , Animais , Relação Dose-Resposta a Droga , Larva/efeitos dos fármacos , Fatores de Tempo
17.
J Am Mosq Control Assoc ; 22(3): 515-22, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17067055

RESUMO

The larvicidal activity and repellency of 5 plant essential oils--thyme oil, catnip oil, amyris oil, eucalyptus oil, and cinnamon oil--were tested against 3 mosquito species: Aedes albopictus, Ae. aegypti, and Culex pipiens pallens. Larvicidal activity of these essentials oils was evaluated in the laboratory against 4th instars of each of the 3 mosquito species, and amyris oil demonstrated the greatest inhibitory effect with LC50 values in 24 h of 58 microg/ml (LC90 = 72 microg/ml) for Ae. aegypti, 78 microg/ml (LC90 = 130 microg/ml) for Ae. albopictus, and 77 microg/ml (LC90 = 123 microg/ml) for Cx. p. pallens. The topical repellency of these selected essential oils and deet against laboratory-reared female blood-starved Ae. albopictus was examined. Catnip oil seemed to be the most effective and provided 6-h protection at both concentrations tested (23 and 468 microg/ cm2). Thyme oil had the highest effectiveness in repelling this species, but the repellency duration was only 2 h. The applications using these natural product essential oils in mosquito control are discussed.


Assuntos
Culicidae , Repelentes de Insetos , Inseticidas , Óleos de Plantas , Aedes , Animais , Cinnamomum zeylanicum , Culex , Eucalyptus , Feminino , Humanos , Larva , Nepeta , Thymus (Planta)
18.
Mem Inst Oswaldo Cruz ; 101(1): 9-13, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16612506

RESUMO

A polyhistidine-tagged recombinant tegumental protein Schistosoma japonicum very lowdensity lipoprotein binding protein (SVLBP) from adult Schistosoma japonicum was expressed in Escherichia coli. The affinity purified rSVLBP was used to vaccinate mice. The worm numbers and egg deposition recovered from the livers and veins of the immunized mice were 33.5% and 47.6% less than that from control mice, respectively (p<0.05). There was also a marked increase in the antibody response in vaccinated mice: the titer of IgG1 and IgG2a, IgG2b in the vaccinated group was significantly higher than that in the controls (>1:6,400 in total IgG). In a comparison of the reactivity of sera from healthy individuals and patients with rSVLBP, recognition patterns against this parasite tegumental antigen varied among different groups of the individuals. Notably, the average titres of anti-rSVLBP antibody in sera from faecal egg-negative individuals was significantly higher than that in sera from the faecal egg-positives, which may be reflect SVLBP-specific protection. These results suggested that the parasite tegumental protein SVLBP was a promising candidate for further investigation as a vaccine antigen for use against Asian schistosomiasis.


Assuntos
Anticorpos Anti-Helmínticos/imunologia , Histidina/imunologia , Lipoproteínas VLDL/imunologia , Schistosoma japonicum/imunologia , Animais , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Contagem de Ovos de Parasitas , Ligação Proteica/imunologia , Proteínas Recombinantes/imunologia , Esquistossomose Japônica/prevenção & controle , Vacinas Sintéticas/imunologia
19.
Mem. Inst. Oswaldo Cruz ; 101(1): 9-13, Feb. 2006. graf
Artigo em Inglês | LILACS | ID: lil-423560

RESUMO

A polyhistidine-tagged recombinant tegumental protein Schistosoma japonicum very lowdensity lipoprotein binding protein (SVLBP) from adult Schistosoma japonicum was expressed in Escherichia coli. The affinity purified rSVLBP was used to vaccinate mice. The worm numbers and egg deposition recovered from the livers and veins of the immunized mice were 33.5 percent and 47.6 percent less than that from control mice, respectively (p<0.05). There was also a marked increase in the antibody response in vaccinated mice: the titer of IgG1 and IgG2a, IgG2b in the vaccinated group was significantly higher than that in the controls (>1:6,400 in total IgG). In a comparison of the reactivity of sera from healthy individuals and patients with rSVLBP, recognition patterns against this parasite tegumental antigen varied among different groups of the individuals. Notably, the average titres of anti-rSVLBP antibody in sera from faecal egg-negative individuals was significantly higher than that in sera from the faecal egg-positives, which may be reflect SVLBP-specific protection. These results suggested that the parasite tegumental protein SVLBP was a promising candidate for further investigation as a vaccine antigen for use against Asian schistosomiasis.


Assuntos
Humanos , Animais , Feminino , Camundongos , Anticorpos Anti-Helmínticos/imunologia , Histidina/imunologia , Lipoproteínas VLDL/imunologia , Proteínas Recombinantes/imunologia , Schistosoma japonicum/imunologia , Vacinas Sintéticas/imunologia , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/imunologia , Camundongos Endogâmicos BALB C , Contagem de Ovos de Parasitas , Ligação Proteica/imunologia , Esquistossomose Japônica/prevenção & controle
20.
Artigo em Chinês | MEDLINE | ID: mdl-16042176

RESUMO

OBJECTIVE: To investigate the protective immunity against Schistosoma japonicum in mice immunized with recombinant specific very low density lipoprotein binding protein (SVLBP) and its potential as vaccine candidate. METHODS: Recombinant SVLBP antigen was over-expressed under IPTG induction and purified by Ni-NTA affinity chromatography. C57BL/6 mice were immunized three times with purified reSVLBP complexed with Freund's adjuvant, at biweekly intervals. Then 35+/-1 cercariae of S. japonicum were given to each mouse by abdominal skin 10 days after the 3rd immunization. 45 days later, all mice were sacrificed to collect adult worms and count liver eggs. serum samples were collected before immunization and after challenge respectively, and were probed the antigen-specific antibodies using a panel of ELISAs. RESULTS: The worm burden and the egg deposition in liver tissue were reduced by 33.4% and 47.6% respectively in the immunized group, in comparison with the adjuvant control group (P<0.05). Higher titer (>1:6 400) of total IgG was observed after challenge infection. The vaccinated mice developed significantly higher levels of IgG2a, IgG2b, IgG1 than those of control mice. CONCLUSION: The recombinant tegumental SVLBP antigen could induce partial protection against S. japonicum infection. These data demonstrate the potential of SVLBP as a schistosome vaccine candidate.


Assuntos
Proteínas de Transporte/imunologia , Lipoproteínas VLDL/imunologia , Schistosoma japonicum/imunologia , Vacinas Sintéticas/imunologia , Animais , Anticorpos Anti-Helmínticos/sangue , Feminino , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos C57BL , Contagem de Ovos de Parasitas , Proteínas Recombinantes/imunologia , Esquistossomose Japônica/prevenção & controle
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