Identification of chemical constituents of Xiaochengqi Decoction by UPLC-Q-TOF/Fast DDA combined with UNIFI software / 中国中药杂志

Based on the combination of ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF) and Waters UNIFI software, the chemical constituents of the classic prescription Xiaochengqi Decoction were qualitatively analyzed and identified. The UPLC conditions are as follows: Acquity HSS T3 reverse phase column(2.1 mm ×100 mm, 1.8 μm), column temperature of 30 ℃, mobile phase of 0.1% formic acid aqueous solution(A)-acetonitrile(B), and flow rate of 0.3 mL·min~(-1). High-resolution MS data of Xiaochengqi Decoction were collected in ESI~(+/-) modes by Fast DDA. The structures of the chemical constituents were tentatively characterized or identified by UNIFI software according to the retention time of reference standards and characteristic fragment ions in MS profile, and literature data. A total of 233 components in Xiaochengqi Decoction were identified, with 93 from wine-processed Rhei Radix et Rhizoma, 104 from bran-processed Aurantii Fructus Immaturus, and 36 from ginger-processed Magnoliae Officinalis Cortex. These 233 components included anthraquinones, flavonoids, lignans, alkaloids, coumarins, and phenylethanoid glycosides. The result provided experimental evidence for the further study on establishment of quality standard and product development of the formula.

Serie parasitosis en dermatología: tungiasis / Dermatology iconography: tungiasis

La tungiasis es una ectoparasitosis causada por la penetración en la piel de la pulga hembra Tunga penetrans. Esta enfermedad no es específica del hombre y se distribuye en regiones cálidas y secas alrededor del mundo. Se adquiere por contacto directo con el suelo en donde habitan los parásitos adultos. En zonas endémicas, su alta prevalencia se asocia a pobreza y falta de acceso al sistema de salud. Además es frecuente entre viajeros que visitan regiones endémicas y que regresan a sus lugares de origen. Presentamos un caso típico de tungiasis en un paciente 39 años que había realizado un viaje reciente a zona endémica. (AU)

Tungiasis is an ectoparasitosis caused by penetration into the skin of the female flea Tunga penetrans. This disease is not human-specific and is distributed worldwide in warm, dry regions. It is acquired by direct contact with the soil where the adult parasites live. In endemic areas, its high prevalence is associated with poverty and lack of access to the health system. It is also frequent among travelers visiting endemic regions and returning to their places of origin. We present a typical case of tungiasis in a 39 year old patient who had made a recent trip to an endemic area. (AU)

Direct effect of p, p'-DDT on mice liver

ABSTRACT Contact with the pesticide dichlorodiphenyltrichloroethane (p,p′-DDT) can be the cause of various harmful effects in humans, wildlife, and the environment. This pesticide is known to be persistent, lipophilic, resistant to degradation, and bioaccumulive in the environment and to be slowly released into bloodstream. Growing evidence shows that exposure to DDT is linked to type 2 diabetes mellitus. Individuals exposed to elevated levels of DDT and its metabolite have an increased prevalence of diabetes and insulin resistance. To evaluate these possible relationships, experiments were performed on eight-week-old female mice, divided into three groups (n = 10 per group): Group 1 received a vehicle-control intraperitoneal (i.p.) injection of sesame oil; Groups 2 and 3 received an i.p. dose of 50 and 100 µg/g p,p′-DDT respectively, dissolved in sesame oil. All groups were treated once daily for four days. Real-time PCR analysis of several genes was undertaken. Additionally, biochemical parameters and histopathological changes were measured. NQO1, HMOX1, NR1I3 and NR3C1 were up-regulated in DDT-exposed animals compared to the vehicle control group, while only SREBP1 was down-regulated in the 100 µg/g group. MTTP and FABP5, not previously reported for DDT exposure, but involved in regulation of fatty acid fluxes, could also function as biomarkers cross-talking between these signaling pathways. These results suggest that beyond epidemiological data, there is increasing molecular evidence that DDT may mimic different processes involved in diabetes and insulin resistance pathways.

RESUMO O contato com o praguicida diclorodifeniltricloroetano (p, p'-DDT) pode ser a causa de vários efeitos nocivos sobre os seres humanos, animais silvestres e o meio ambiente. Sabe-se de sua característica de bioacumulação, ser altamente persistente no meio ambiente, lipofílico, resistente à degradação e lentamente liberado na corrente sanguínea. Existe uma evidência crescente de que a exposição ao DDT pode ser ligada a Diabetes mellitus tipo 2. Os indivíduos expostos a níveis elevados de DDT e seu metabólito apresentam maior prevalência de diabetes e resistência à insulina. A fim de obter informações sobre essas possíveis relações, camundongos fêmeas de oito semanas de idade foram divididos em três grupos (n = 10 por grupo): Grupo 1 recebeu um veículo de óleo de gergelim via i.p.; os Grupos 2 e 3 receberam, via i.p., 50 e 100 µg/g de p, p'-DDT, respectivamente, dissolvidos em óleo de gergelim. Todos os grupos foram tratados uma vez ao dia durante quatro dias. Além da análise de PCR em Tempo Real de vários genes, os parâmetros bioquímicos e alterações histopatológicas também foram medidos. A expressão gênica do mRNA dos genes NQO1, HMOX1, NR1I3 e NR3C1 foi maior nos animais expostos ao DDT, em comparação ao grupo controle, enquanto a expressão gênica do SREBP1 diminuiu na concentração de 100 µg/g. Os genes MTTP e FABP5 envolvidos na regulação do fluxo de ácidos graxos, embora não estudados quanto à exposição ao DDT, também podem funcionar como biomarcadores de resposta cruzada entre essas vias de sinalização. Esses resultados sugerem que, além de dados epidemiológicos, há cada vez mais evidências moleculares de que o DDT poderia, de fato, imitar diferentes processos que envolvem as rotas de diabetes e de resistência à insulina.

PCBs and DDTs in surface mangrove sediments from the south of Iran [ID NO. 048]

Mangrove sediments were collected during wet and dry seasons from nine stations in Khamir, Laft and natural reservoir mangrove-dense areas of Hormozgan province in the south of Iran. SIGMA PCBs ranged from 5.33 to 15.5 ng/g dry weight and the dominant congener was no.153. Average SIGMA DDTs for Khamir and Laft mangroves were 16.58 +/- 1.51 and 18.8 +/- 9.98 ng/g dry weight. DDT was more abundant than DDE and DDD isomers, which indicated the input of DDT. The sediment quality guideline shows that the concentration of SIGMA PCBs were below the ER-M guideline, whereas levels of SIGMA DDTs were between ER-L and ER-M. The mangrove ecosystem in Hormozgan province is suffering from urban and industrial development

Effects of bisphenol A and DDT on mRNA expression of vitellogenin II in liver of quail embryos

This study was conducted to reveal the estrogenic effects of bisphenol A and o, p'-DDT on quail embryos. Thirteen fertilized eggs were used as control [injected with 20 microl corn oil], 15 eggs were injected with estradiol 17beta [0.04 mg dissolved in 20 microl corn oil], 20 eggs were injected with BPA [2 mg dissolved in 20 microl corn oil] and 20 eggs were injected with o, p'-DDT [2 mg dissolved in 20 microl corn oil] at day 13 of incubation. Two days later the livers of the embryos were collected. The DNA was extracted from the liver for molecular sexing, while total RNA was extracted for vitellogenin II [VTGII] mRNA expression in embryos. In female embryos, BPA and o, p'-DDT induced variable levels of VTGII mRNA expression, while in male embryos, o, p'-DDT induced a slightly VTGII mRNA expression. In contrast, there was no expression of VTGII after BPA injection. In conclusion, the estrogenicity of BPA was lower than o, p'-DDT and both of them were lower than the estradiol 17beta

O uso de inseticidas na Saúde Pública: uma crítica ao modelo de combate à dengue no Brasil e no DF / The use of insecticides in Public Health: a critique of the model for combating dengue in Brazil and DF

O presente trabalho tem como objetivo principal o de questionar o modelo químico que vem sendo utilizado para o controle de vetores da dengue no Brasil, considerando referenciais da bioética. A dengue é uma doença reemergente que apresenta casos em regiões tropicais e subtropicais. É causada por um vírus e transmitida pelo mosquito do gênero Aedes. Há registros de dengue no Brasil desde de 1846. Com os casos aumentando nas décadas de 1980 e 1990, a dinâmica de planos emergenciais precipitaram o surgimento de um primeiro programa para erradicação do mosquito transmissor: o Plano Diretor de Erradicação do Aedes aegypti (PEAa). Com o insucesso do seu objetivo principal, novos planos ou programas se sucederam: o Plano de Intensificação das Ações de Controle do Dengue (PIACD), o Programa Nacional de Controle da Dengue (PNCD) até o último e atualmente implementado, o Diretrizes Nacionais para a Prevenção e Controle de Endemias da Dengue (DNPCED). Todos esses planos apresentaram o controle químico do vetor como sustentáculo principal. Utilizando de métodos qualitativo e quantitativo foram feitas análises de dados epidemiológicos da dengue, de parâmetros relacionados ao Aedes aegypti, história oral de vida, análise de conteúdo e aplicação de questionários para a construção de uma crítica aos modelos utilizados. Os resultados apontaram que os objetivos principais dos programas não foram cumpridos e que muitas das recomendações preconizadas nos documentos não estão sendo praticadas, por servidores e gestores. A análise de artigos científicos sinaliza ainda que os inseticidas utilizados, como o malation, são perigosos para a saúde humana e para o meio ambiente e, na prática, não estão controlando a situação epidemiológica da dengue no Brasil

The present work aims to question the chemical model that has been used for the control of dengue vectors in Brazil , considering principles of bioethics . Dengue is a reemerging disease presenting cases in tropical and subtropical regions . It is caused by a virus and transmitted by mosquitoes of the genus Aedes . There are records of dengue in Brazil since 1846 . With the increasing cases in the 1980s and 1990s , the dynamics of emergency plans precipitated the emergence of a first program to eradicate the mosquito : the Master Plan for the Eradication of Aedes aegypti ( PEAa ) . With the failure of its main purpose , new plans or programs have succeeded : the Plan of Actions Intensification dengue control ( PIACD ) , the National Dengue Control Program ( PNCD ) to last and currently implemented, the National Guidelines for Prevention and Control of Dengue Epidemics ( DNPCED ) . All these plans had chemical control vector as backbone . Using qualitative methods and quantitative analysis of epidemiological data of dengue, Aedes aegypti related to oral life history , discourse analysis and questionnaires to construct a critique of the models used parameters were made . The results showed that the main objectives of the program were not met and that many of the recommendations issued in the documents are not being charged for servers and managers . The analysis of scientific articles also indicates that insecticides such as malathion, are dangerous to human health and the environment and , in practice, are not controlling the epidemiological situation of dengue in Brazil

El presente trabajo tiene como objetivo cuestionar el modelo químico que se ha utilizado para el control de los vectores del dengue en Brasil , teniendo en cuenta los principios de la bioética . El dengue es una enfermedad reemergente la presentación de casos en las regiones tropicales y subtropicales. Es causada por un virus y transmitida por mosquitos del género Aedes . Existen registros de dengue en Brasil desde 1846. Con el aumento de los casos en los años 1980 y 1990 , la dinámica de los planes de emergencia precipitan la aparición de un primer programa para erradicar el mosquito : el Plan Maestro para la Erradicación del Aedes aegypti ( PEAa ) . Con el fracaso de su objetivo principal , los nuevos planes o programas han tenido éxito : el Plan de Intensificación acciones de control del dengue ( PIACD ) , el Programa Nacional de Control del Dengue ( PNCD ) para durar y aplicado en la actualidad, las directrices nacionales para la Prevención y Control del dengue epidemias ( DNPCED ) . Todos estos planes tuvieron el control químico de vectores como columna vertebral . El uso de métodos cualitativos y el análisis cuantitativo de los datos epidemiológicos de dengue, Aedes aegypti relacionados con la historia de vida oral, análisis del discurso y cuestionarios para la construcción de una crítica de los modelos se hicieron parámetros utilizados . Los resultados mostraron que los principales objetivos del programa no se cumplieron y que muchas de las recomendaciones emitidas en los documentos no están cobrando por los servidores y los administradores . El análisis de artículos científicos también indica que los insecticidas como el malatión , son peligrosos para la salud humana y el medio ambiente y , en la práctica , no son el control de la situación epidemiológica del dengue en Brasil

Impact of changing over of insecticide from synthetic pyrethroids to DDT for indoor residual spray in a malaria endemic area of Orissa, India.

Background & objectives: Development of insecticide resistance in malaria vectors has been a major problem for achieving effective vector control. Due to limited availability of insecticides, the only option is management of resistance by judiciously using the insecticides and rotating them to maintain their effectiveness. This study was carried out in a malaria endemic area of Sundergarh district in Orissa where synthetic pyrethroids (SP) were in use for the last couple of years. The change-over from SP to DDT was done in one arm of study, and the other two arms remained on SP and insecticide-treated nets (ITN). Entomological and parasitological monitoring was done to assess the impact. Methods: The study design comprised of three arms (i) two rounds of indoor residual spraying (IRS) with DDT 1g/m2 as a change-over insecticide in areas previously under synthetic pyrethroids; (ii) two rounds of IRS with synthetic pyrethroid (alphacypermethrin, ACM) @ 25 mg/m2; and (iii) an unsprayed area under ITN/long lasting insecticide nets (LNs). Indoor residual spraying was undertaken under strict supervision to maintain quality and coverage. Contact bioassays were conducted to know the persistence of insecticide on sprayed surfaces and adult vector density was monitored in fixed and randomly selected houses. Malaria incidence was measured through fortnightly domiciliary surveillance under primary health care system in all the study villages. Results: The insecticide susceptibility tests showed that An.culicifacies was resistant to DDT but susceptible to malathion and ACM. However, An. fluviatilis was susceptible to all the three insecticides. ACM was effective in killing An. culicifacies on mud and wooden sprayed surfaces and maintained effective bioefficacy ranging from 92 to 100 per cent up to five months, whereas DDT failed to achieve effective mortality in An.culicifacies. However, there was significant decline in the density of An.culicifacies in ACM and DDT areas in comparison to ITNs/LNs. There was 61 per cent reduction in the slide positivity rate in ACM area in comparison to 48 and 51 per cent in DDT and ITN/LNs areas, respectively. The adjusted incidence rate of malaria cases per 1000 population in three study areas also showed significant declines within each group. Interpretation & conclusions: The present findings show that the change-over of insecticide from synthetic pyrethroids to DDT brings about the same epidemiological impact as envisaged from continuing SP spray or distributing insecticide treated nets/long-lasting insecticidal nets provided there is a good quality spray and house coverage.

Irritability of malaria vector, Anopheles sacharovi to different insecticides in a malaria-prone area

OBJECTIVE@#To determine the susceptibility and irritability level of malaria vector Anopheles sacharovi (An. sachrovi) to different insecticides in a malaria-prone area.@*METHODS@#Susceptibility and irritability levels of field collected strain of An. sacharovi to WHO standard papers of DDT 4%, dieldrin 0.4%, malathion 5%, fenitrothion 1%, permethrin 0.75%, and deltamethrin 0.05% were determined in East Azerbaijan of Iran during reemerging of malaria as described by WHO.@*RESULTS@#Results showed that at the diagnostic dose of insecticides this species exhibited resistance to DDT, tolerant to dieldrin and but somehow susceptible to fenitrothion, malathion, permethrin and deltamethrin. The results of irritability of this species to DDT, lambdacyhalothrin, permethrin cyfluthrin and deltamethrin revealed that DDT had had the most and deltamethrin the least irritancy effect. The average number of take offs/fly/minutes for DDT was 0.8±0.2. The order of irritability for permethrin, lambdacyhalothrin, cyfluthrin and deltamethrin were 0.7±0.2, 0.5±0.2, 0.5±0.3, and 0.2±0.1, respectively.@*CONCLUSIONS@#Results of this study reveals the responsiveness of the main malaria vector to different insecticides. This phenomenon is depending on several factors such as type and background of insecticide used previously, insecticide properties, and physiology of the species. Careful monitoring of insecticide resistance and irritability level of species could provide a clue for appropriate selection of insecticide for malaria control.

Um método chamado Pinotti: sal medicamentoso, malária e saúde internacional (1952-1960) / A method called Pinotti: medicated salt, malaria, and international health (1952-1960)

Analisa a criação, a recepção e o abandono do método Pinotti de combate à malária: sal de cozinha misturado com cloroquina. Idealizado no início da década de 1950 pelo malariologista brasileiro Mario Pinotti como ação profilática e terapêutica contra a malária, foi testado durante a primeira metade daquela década e utilizado no Brasil entre 1959 e 1961, como parte da campanha de erradicação da malária coordenada pela Organização Mundial da Saúde. Conquistou reconhecimento no cenário internacional da saúde, sofreu críticas e foi testado em outros países até meados dos anos 1960. Argumentamos que, no Brasil, o abandono foi devido, sobretudo, ao ocaso político de seu criador, a partir de 1960.

Global status of DDT and its alternatives for use in vector control to prevent disease: [review] / Estado global do DDT e suas alternativas para utilização no controle de vetores para prevenção de doenças: [revisão]

Neste artigo, revisei o estado do dicloro-difenil-tricloroetano (DDT) utilizado no controle de doenças causadas por vetores, e seus benefícios e riscos em relação às alternativas disponíveis. Dados atuais sobre o uso de DDT foram obtidos através de questionários e relatórios, assim como uma busca Scopus para resgatar artigos publicados. Quase 14 países utilizam DDT para controle de doenças, e diversos outros o estão reintroduzindo. A preocupação sobre o uso contínuo de DDT é abastecida por relatórios recentes dos altos níveis de exposição humana associada com a pulverização em recintos fechados, acumulando evidências sobre efeitos crônicos a saúde. Existem sinais de que mais vetores da malária estão se tornando resistentes à ação tóxica do DDT. Métodos químicos efetivos estão disponíveis como alternativas imediatas ao DDT, mas o desenvolvimento da resistência está diminuindo a eficácia das ferramentas de insetização. Métodos não químicos são potencialmente importantes, mas sua efetividade no programa necessita de estudos urgentes. O controle integrado de vetores fornece uma estrutura para o desenvolvimento e a implementação de tecnologias e estratégias efetivas como alternativas sustentáveis à dependência ao DDT.

In this article I reviewed the status of dichlorodiphenyltrichloroethane (DDT), used for disease vector control, and its benefits and risks in relation to the available alternatives. Contemporary data on DDT use were obtained from questionnaires and reports as well as a Scopus search to retrieve published articles. Nearly 14 countries use DDT for disease control, and several others are reintroducing DDT. Concerns about the continued use of DDT are fueled by recent reports of high levels of human exposure associated with indoor spraying amid accumulating evidence on chronic health effects. There are signs that more malaria vectors are becoming resistant to the toxic action of DDT. Effective chemical methods are available as immediate alternatives to DDT, but the development of resistance is undermining the efficacy of insecticidal tools. Nonchemical methods are potentially important, but their effectiveness at program level needs urgent study. To reduce reliance on DDT, support is needed for integrated and multipartner strategies of vector control. Integrated vector management provides a framework for developing and implementing effective technologies and strategies as sustainable alternatives to reliance on DDT.

Deltamethrin: Promising mosquito control agent against adult stage of Aedes aegypti L

OBJECTIVE@#To evaluate the effects of deltamethrin against field-collected adults of Aedes aegypti L. (Ae. aegypti).@*METHODS@#The adults were selected with 0.025% deltamethrin for 40 successive generations. The selected adults were tested with 4% DDT and the emerging larvae were tested with various insecticides to study the cross-resistance spectrum. The knockdown and irritability studies were carried out in adult mosquitoes to investigate their behavioural response to deltamethrin.@*RESULTS@#Forty generations of selection with deltamethrin resulted in only 3.8-fold resistance in the adults of Ae. aegypti. The adults of parent (PS) and selected strains (DAS) exhibited only 0.8-fold cross resistance to 4% DDT. The larvae emerging from the PS and DAS strains did not develop appreciable levels of resistance to various insecticides tested. The knockdown studies revealed KT50 of 14.4 min in PS adults with no signs of recovery even after 24 h. The DAS strains could develop only 1.2 to 1.3-fold knockdown resistance (KDR). The knockdown response of DDT was though 5-6 times slower than deltamethrin but the continued response in deltamethrin-selected adults caused only 1.2-fold KDR. The PS and DAS strains exhibited significant irritability response towards deltamethrin and DDT. The DAS strains showed 5-6 fold increased irritability to deltamethrin as compared to the PS strain.@*CONCLUSIONS@#The above results suggest the prolonged effective use of deltamethrin against Ae. aegypti as an adulticide.

Persistence of DDT, malathion & deltamethrin resistance in Anopheles culicifacies after their sequential withdrawal from indoor residual spraying in Surat district, India.

Background & objectives: Under the national antimalaria programme DDT was introduced in early 1950s for vector control and later hexachloro cyclohexane (HCH) followed by malathion and recently synthetic pyrethroids in 1990s to manage the insecticide resistance in Anopheles culicifacies. Subsequent replacement led to development of multiple resistances in An. culicifacies in Surat district in Gujarat State. Indoor residual spray (IRS) was completely withdrawn in southern villages in Surat in 2002. This study was undertaken in these areas to study the persistence of resistance to DDT, malathion and deltamethrin after sequential withdrawal of IRS with these insecticides at different times. Methods: Susceptibility tests on An. culicifacies were conducted using standard WHO methods and kits. Mortality, knockdown time and lethal times were calculated for An. culicifacies exposed to WHO prescribed diagnostic concentrations of different insecticide impregnated papers. Results: Persistence of DDT-resistance was observed even after 30 yr of its withdrawal from IRS. Similarly, persistence of malathion resistance was also observed after 9 yr of its withdrawal from IRS, while reversal of deltamethrin-resistance was observed very fast within 2-3 yr after its withdrawal from IRS in 2002. Interpretation & conclusion: Present data indicate that the quantum of reversion of insecticide resistance in a population is relative and depends on the genetic stability of the respective resistance genes in the mosquitoes. In the present study withdrawal of pyrethroid-IRS resulted in increased susceptibility against pyrethroids alone and was independent of existence of resistance to insecticides of other groups. This study emphasizes that appropriate rotation of different insecticides; including carbamates may prevent or delay the onset of resistance.

Co-metabolism of DDT by the newly isolated bacterium, pseudoxanthomonas sp. wax

Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical properties, as well as by 16S rRNA gene analysis. In the presence of 100 mg l-1 glucose, the wax strain could degrade over 95 percent of the total DDT, at a concentration of 20 mg l-1, in 72 hours, and could degrade over 60 percent of the total DDT, at a concentration of 100 mg l-1, in 144 hours. The wax strain had the highest degradation efficiency among all of the documented DDT-degrading bacteria. The wax strain could efficiently degrade DDT at temperatures ranging from 20 to 37ºC, and with initial pH values ranging from 7 to 9. The bacterium could also simultaneously co-metabolize 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 2,2-bis(p-chlorophenyl)-1,1-dichlorethylene (DDE), and other organochlorine compounds. The wax strain could also completely remove 20 mg kg-1 of DDT from both sterile and non-sterile soils in 20 days. This study demonstrates the significant potential use of Pseudoxanthomonas sp. wax for the bioremediation of DDT in the environment.

Trends of poisoning in Faridkot region of Punjab- A retrospective study of one year.

Since immemorial times, poisonous substances have been reported to be adversely affecting human life, both in terms of morbidity and mortality. Evolution in fields like agriculture, industry etc has made wide and easy availability of various poisonous substances. The present study is a retrospective study of one year which is related to poisoning cases that were admitted in the emergency department of G.G. S. Medical College, Faridkot from 1st January 1996 to 31st December 1996. The analysis of the data revealed that out of 78 patients admitted in the hospital, 31 patients died. The maxi-mum incidence was seen in the age group of 21-30 years with males outnumbering the females. The commonest poison used was organophosphorus group of compounds.

Susceptibilidad de Aedes aegypti a DDT, deltametrina y lambdacialotrina en Colombia / Susceptibility of Aedes aegypti to DDT, deltamethrin, and lambda-cyhalothrin in Colombia

OBJETIVOS: Evaluar el estado de susceptibilidad a insecticidas piretroides deltametrina y lambdacialotrina y al organoclorado DDT, e identificar los mecanismos bioquímicos asociados con resistencia en 13 poblaciones naturales de Aedes aegypti recolectadas en localidades de Colombia donde el dengue es un grave problema de salud pública. MÉTODOS: Se recolectaron y criaron en condiciones controladas formas inmaduras de diferentes criaderos naturales del vector para cada localidad. Con la generación F2 se realizaron bioensayos utilizando las metodologías OMS 1981 (papeles impregnados) y CDC 1998 (botellas impregnadas). En las poblaciones con mortalidades compatibles con disminución de la susceptibilidad, se midieron los niveles de esterasas no específicas (ENE), oxidasas de función mixta (OFM) y acetilcolinesterasa modificada (ACEM) mediante pruebas colorimétricas. RESULTADOS: Todas las poblaciones del mosquito evaluadas evidenciaron resistencia al organoclorado DDT. En cuanto a los piretroides, se encontró resistencia generalizada a lambdacialotrina pero no a deltametrina. Los mecanismos bioquímicos de resistencia evaluados permitieron encontrar 7 de 11 poblaciones con ENE elevadas y una población con OFM incrementadas. CONCLUSIONES: Se descarta la resistencia cruzada de tipo fisiológico entre el DDT y lambdacialotrina en las poblaciones de A. aegypti evaluadas. La resistencia fisiológica a lambdacialotrina parece asociarse con el incremento de las ENE. El comportamiento diferencial en los niveles de susceptibilidad y los valores enzimáticos entre poblaciones se asociaron con la variabilidad genética y presión de selección química a nivel local.

OBJECTIVES: To assess the susceptibility status of 13 natural populations of Aedes aegypti (collected from sites in Colombia where dengue is a serious public health problem) to the pyrethroids, deltamethrin and lambda-cyhalothrin, and to the organochlorine, DDT, and to identify any biochemical mechanisms associated with resistance. METHODS: Immature forms of the vector were collected from natural breeding spots at each site and then raised under controlled conditions. Using the F2 generation, bioassays were performed using the World Health Organization's 1981 methodology (impregnated paper) and United States Centers for Disease Control and Prevention's 1998 methodology (impregnated bottles). In populations where mortality rates were consistent with decreased susceptibility, levels of nonspecific esterases (NSE), mixed-function oxidases (MFO), and acetylcholinesterase (AChE) were measured using colorimetric tests. RESULTS: All of the mosquito populations that were tested showed resistance to the organochlorine DDT. In the case of the pyrethroids, widespread resistance to lambda-cyhalothrin was found, but not to deltamethrin. Assessing the biochemical resistance mechanisms showed that 7 of the 11 populations had elevated NSE, and one population, increased MFO. CONCLUSIONS: Physiological cross-resistance between DDT and lambda-cyhalothrin in the A. aegypti populations tested was dismissed. Physiological resistance to lambda-cyhalothrin appears to be associated with increased NSE. The differences in susceptibility levels and enzyme values among the populations were associated with genetic variations and chemicals in use locally.

Catalytic hydrodechlorination of organochlorine pesticide [DDT] in alkaline 2-propanol

Catalytic Hydrodechlorination of DDT [1, 1-bis[4-chlorophenyl]-2, 2, 2-trichloroethane] was carried out in an alcohol solution containing base compound in the presence of carbon supported transition metals [Fe, Co, Ni]. It was found that dechlorination of DDT to chlorine-free product effectively occurred in a 2-propanol/methanol [99:1 v/v] solution of a base compound NaOH in the presence of carbon supported Fe-Ni catalyst at temperature below 82°C for 4 hrs. At the concentration 3.5-3500 mg/ml were converted within the detection limit of electron capture detection gas chromatography [GC-ECD]

Vector density and the control of kala-azar in Bihar, India

Bihar, India has been in the grip of kala-azar for many years. Its rampant and severe spread has made life miserable in most parts of the state. Such conditions require a comprehensive understanding of this affliction. The numbers coming out of the districts prone to the disease in the north and south Ganges have provided us with several startling revelations, as there are striking uniformities on both sides, including similar vegetation, water storage facilities, house construction and little change in risk factors. The northern areas have been regularly sprayed with DDT since 1977, but eradication of the disease appears to be a distant dream. In 2007 alone, there were as many as 37,738 cases in that region. In contrast, the southern districts of Patna and Nalanda have never had the disease in its epidemic form and endemic disease has been present in only some pockets of the two districts. In those cases, two rounds of spraying with DDT had very positive results, with successful control and no new established foci. In addition, an eleven-year longitudinal study of the man hour density and house index for the vector Phlebotomus argentipes demonstrated that they were quite high in Patna and Nalanda and quite low in north Bihar. Given these facts, an attempt has been made to unravel the role of P. argentipes saliva (salivary gland) in the epidemiology of kala-azar. It was determined that patchy DDT spraying should be avoided for effective control of kala-azar.

Estudio del sistema purinérgico a través de la caracterización de la enzima E-NPP3 y de la secreción de ATP en células uroepiteliales de la vejiga urinaria del ratón / Study of the purinergic system through the characterization of the E-NPP3 enzyme and the secretion of ATP in uroepithelial cells of the urinary bladder of the mouse

El presente trabajo involucra el estudio del sistema purinérgico mediante la purinérgico mediante la purificación y la caracterización bioquimica de la ecto-enzima E-NPP3 soluble, la cual modula la activación de los receptores purinérgicos mediante la hidrólisis de los nucleótidos extracelulares. La purificación de esta enzima, expresada en la línea celular CHO-K1, requirió el empleo de diferentes columnas cromatográficas; comprobándose la pureza, mediante la determinación de la actividad enzimática, la cuantificación de las proteínas y la detección de dicha enzima. Los resultados de la caracterización de la E-NPP3 indican que presentan un ph óptimo alcalino y que su actividad depende de la la concentración de los iones calcio y magnesio: mientras que el imidazol y el DDT ejercen acciones inhibidoras sobre su actividad. La purificación de la enzima E-NPP3 soluble representa un primer paso para futuros estudios que permitan su cristalización lo cual, constituirá una herramienta en la elaboración de agonistas y antagonistas selectivos o de anticuerpos monoclonales contra dicha enzima, útiles en el diagnóstico o el tratamiento de condiciones patológicas como el cáncer de colon y la colangiocarcinoma. Adicionalmente, teniendo en cuenta que se ha demostrado la disminución de la expresión de las ecto-nucleotidasas en el uroepitelio de pacientes que padecen cistitis intersticial; el presente trabajo comprende también, el desarrollo de un modelo de órgano aislado, la vejiga urinaria del ratón, para el estudio de la secreción de ATP desde las células uroepiteliales. Dicho modelo permitió demostrar, mediante estudios electrofisiológicos y el uso de diferentes fármacos, la contriución de los receptores purinérgicos sobre la actividad eléctrica del nervio pélvico cuando la vejiga es sometida a distensión mecánica gradual; sugiriendo la importancia de estos receptores en la transducción mecanosensorial de dicho órgano y permitiendo inferir la posible interrelación con los receptores de vaniloides en la detección de los estímulos sensoriales por parte del uroepitelio

Mixed-function oxidases and esterases associated with cross-resistance between DDT and lambda-cyhalothrin in Anopheles darlingi Root 1926 populations from Colombia

In order to establish the insecticide susceptibility status for Anopheles darlingi in Colombia, and as part of the National Network on Insecticide Resistance Surveillance, five populations of insects from three Colombian states were evaluated. Standardised WHO and CDC bottle bioassays, in addition to microplate biochemical assays, were conducted. Populations with mortality rates below 80 percent in the bioassays were considered resistant. All field populations were susceptible to deltamethrin, permethrin, malathion and fenitrothion. Resistance to lambda-cyhalothrin and DDT was detected in the Amé-Beté population using both bioassay methods with mortality rates of 65-75 percent. Enzyme levels related to insecticide resistance, including mixed function oxidases (MFO), non-specific esterases (NSE), glutathione S-transferases and modified acetylcholinesterase were evaluated in all populations and compared with a susceptible natural strain. Only mosquitoes from Amé-Beté presented significantly increased levels of both MFO and NSE, consistent with the low mortalities found in this population. The continued use of lambda-cyhalothrin for An. darlingi control in this locality has resulted in a natural resistance to this insecticide. In addition, DDT resistance is still present in this population, although this insecticide has not been used in Colombia since 1992. Increased metabolism through MFO and NSE may be involved in cross-resistance between lambda-cyhalothrin and DDT, although kdr-type nerve insensitivity cannot be discarded as a possible hypothesis. Additional research, including development of a kdr specific assay for An. darlingi should be conducted in future studies. Our data demonstrates the urgent need to develop local insecticide resistance management and surveillance programs throughout Colombia.