Diaz C

References (13)

Title : [Determination of glutathione-S-transferase activity in Culex quinquefaciatus strains in Cuba and other Latin American countries] - Diaz_2004_Rev.Cubana.Med.Trop_56_111
Author(s) : Diaz C , Rodriguez MM , Fresneda M , Bisset JA
Ref : Rev Cubana Med Trop , 56 :111 , 2004
Abstract : In the present paper, we standardized a microtitration assay for the determination of specific activity of glutathione-S-transferase using a Culex quinquefasciatus strain selected in lab with pyrethroid insecticide lambdacyhalothrin for 6 generations (SP6). The saturation values for reduced glutathione and 1-chlorine 2,4-dinitrobenzene were 15 mM and 40 mM, respectively; we also estimated that 3 minutes was the optimal time in order to differentiate resistant strain SP6 from the susceptible reference strain S-Lab (p>0.05). Additionally, the optimized microtitration method allowed testing 4 Culex strains from Cuba (SANTIAGO DE CUBA, SD4, QUIBU AND SP6), one from Venezuela (MIRANDA), one from Colombia (MEDELLIN) and the other from Brazil (RIO DE JANEIRO) for glutathione-S-transferase activity. MIRANDA showed the highest activity for this detoxifying enzyme. However, the mechanism of detoxyfication in all the strains was very unfrequent, which indicates that its role in resistance to insecticide for all the studied strains is not so important. Glutathione-S-transferase values were compared with non-specific esterase and altered acetylcholinesterase frequencies for each of the studied strains.
ESTHER : Diaz_2004_Rev.Cubana.Med.Trop_56_111
PubMedSearch : Diaz_2004_Rev.Cubana.Med.Trop_56_111
PubMedID: 15846907

Title : [Status of resistance to insecticides in field strains of the Blatella germanica species (Dictyoptera: Blattellidae) from Pinar del Rio municipality] - Diaz_2003_Rev.Cubana.Med.Trop_55_196
Author(s) : Diaz C , Enriquez D , Bisset JA
Ref : Rev Cubana Med Trop , 55 :196 , 2003
Abstract : A study of the levels of resistance to 10 insecticides: 4 organophosphate compounds (malathion, clorpirifos, methylpyrimifos and diazinon), 2 carbamates (propoxur and bendiocarb) and 4 pyrethroids (cypermethrin, deltamethrin, lamdacyhalothrin and cyfluthrin) was conducted in 5 strains of Blatella germanica (Linnaeus, 1767) collected in the field of Pinar del Rio. High levels of resistance to bediocarb, cypermethrin and deltamethrin insecticides; low level of resistance to diazinon; from moderate to high resistance to methyl-pyrimifos, as well as susceptibility to one insecticide in each study group: clorpirifos (organophosphate), propoxur (carbamate) and cyfluthrin (pyrethroid); were detected. Only a strain presented low resistance to malathion (Inicio Carlos Manuel) and to lambda-cyhalothrin (Consejo Celso Maragoto). Cypermethrin-deltamethrin cross resistance was evidenced. It did not affect the susceptibility to lambda-cyalothrin and cyfluthrin.
ESTHER : Diaz_2003_Rev.Cubana.Med.Trop_55_196
PubMedSearch : Diaz_2003_Rev.Cubana.Med.Trop_55_196
PubMedID: 15849926

Title : [Cross resistance to pyrethroids in Aedes aegypti from Cuba induced by the selection with organophosphate malathion] - Rodriguez_2003_Rev.Cubana.Med.Trop_55_105
Author(s) : Rodriguez MM , Bisset JA , Diaz C , Soca LA
Ref : Rev Cubana Med Trop , 55 :105 , 2003
Abstract : A strain from Aedes aegypti (L) collected in the municipality of Santiago de Cuba with low levels of resistance to malathion (1.79x) was subjected to selection pressure aimed at evaluating the evolution of the resistance to this organophosphate and its usefulness for control. After 5 generations of selection (SAN-F5) with malathion, it was not possible to increase the resistance and it was obtained a value of resistance factor (FR50) of 2.22x. None or little cross resistance to the following organophosphate insecticides was observed: fenthion, temephos and fenitrotion; however, it was found an elevated cross resistance to deltamethrin pyrethroid, with a value of 287.5x in the third generation of selection. It was also observed cross resistance to other pyrethroids (lambda-cyhalothrin, cypermethrin and ciflutrine). The mechansim of elevated esterases did not generate resistance to pyrethroids, which was corroborated through inhibition gel studies and through the calculation of the frequency in microtitering plaques. Nevertheless, there was an increase in the frequency of the glutathione-s-transferase mechanism from 0.049 in Santiago de Cuba to 0.42 in SAN-F5, which may be associated with the resistance to pyrethroids. The cross resistance to pyrethroids, mainly to deltamethrin, resulting from the selection with malathion may limit the use of these insecticides in the control unless a good strategy for their use is laid down.
ESTHER : Rodriguez_2003_Rev.Cubana.Med.Trop_55_105
PubMedSearch : Rodriguez_2003_Rev.Cubana.Med.Trop_55_105
PubMedID: 15849966

Title : [Comparative analysis of resistance to insecticides in strains of Culex quinquefasciatus, from Camaguey] - Dieguez_2000_Rev.Cubana.Med.Trop_51_26
Author(s) : Dieguez Fernandez L , Bisset JA , Rodriguez MM , Gonzalez T , Diaz C , Vazquez R
Ref : Rev Cubana Med Trop , 51 :26 , 2000
Abstract : The organophosphate, carbamate and pyrethroid resistance levels in 14 strains of Culex quinquefasciatus from Camagey were studied by bioassays and biochemical tests in larvae with or without synergists. The use of electrophoresis in polyacrylamide gel (PAGE) allowed to identify 8 patterns of esterases, among which A3A6B6, BiB6 and B1A6B6 were the most frequent. It was observed that 6 years after the suspension of malathion, there is still resistance to this product. There was also cross resistance to propoxur. Detoxification mechanisms for deltamethryn are being developed. The most important physiological mechanisms were: elevated esterases in the resistance to malathion, modified AchE for propoxur and oxidases of multiple function for deltamethryn. In relation to the genic frequencies, the modified AchE mechanisms was more extended than that of the elevated esterases in these populations of mosquitoes of the central region of Cuba.
ESTHER : Dieguez_2000_Rev.Cubana.Med.Trop_51_26
PubMedSearch : Dieguez_2000_Rev.Cubana.Med.Trop_51_26
PubMedID: 10887552

Title : [Levels of insecticide resistance and its mechanisms in a strain of Aedes aegypti of Santiago de Cuba] - Rodriguez_1999_Rev.Cubana.Med.Trop_51_83
Author(s) : Rodriguez MM , Bisset JA , Mila LH , Calvo E , Diaz C , Alain Soca L
Ref : Rev Cubana Med Trop , 51 :83 , 1999
Abstract : As a result of the most recent dengue outbreak in Santiago de Cuba province, a strain of this vector was studied to determine the levels of sensitivity and/or resistance to organophosphate and pyrethoid insecticides. The results of bioassays showed low levels of resistance to fention, malathion and deltametrine, moderate levels of resistance to temephos, metyl-pirimifos and cipermetrine and high levels of resistance to chlorpirifios. According to the results obtained from the use of S.S.S. phosphotrithiate trybutil synergist, it was shown that esterases play an important role in resistance to temephos and chlorpirifos. Piperonyl butoxide synergist disclosed that multifunction oxidases were not involved in the resistance to any of the evaluated insecticides. Biochemical techniques were applied to detect esterase-, glutathione-S-transferase- and acetylcholineaterase-mediated resistance mechanisms of Aedes aegypti. In accordance with the high frequency values observed in each of the mechanisms, it was proved that esterases and glutathione-S-transferase were involved in the insecticide resistance but acetylcholinesterases were not. However, acetylcholinesterase gen was found in Aedes aegypti for the first time though at low frequency. The polyacrylamide-gel electrophoresis made it possible to observe a well-stained band with a relative mobility value of 0.779; this band was called A4 it was not observed in the reference strain and may be associated to organophosphate resistance which remains to be proved in future research.
ESTHER : Rodriguez_1999_Rev.Cubana.Med.Trop_51_83
PubMedSearch : Rodriguez_1999_Rev.Cubana.Med.Trop_51_83
PubMedID: 10887565

Title : [Characterization of resistance to organophosphate insecticides, carbamates, and pyrethroids in Culex quinquefasciatus from the State of Miranda, Venezuela] - Bisset_1999_Rev.Cubana.Med.Trop_51_89
Author(s) : Bisset JA , Rodriguez MM , Diaz C , Alain Soca L
Ref : Rev Cubana Med Trop , 51 :89 , 1999
Abstract : Resistance of Culex quinquefasciatus from Miranda, Venezuela to the organophosphate insecticides malathion and chlorpirifos was higher than 30x whereas resistance to pyrethroids metylpirimifos, fention, cipametrine, deltametrine, permetrine and lambdacyalotrine and to organochlorate DDT was lower than 4x. Resistance mechanisms were analyzed with piperonyl butoxide synergist (multifunction oxidases) and S.S.S. phosphotrithiate tributyl (DEF, esterase inhibitor). Multifunction oxidases did not play a significant role in resistance to organophosphate insecticides and carbamate; however, esterases were only mechanisms of resistance to malathion and chlorpirifos. The only insecticide affected by DEF and PB was cipermetrine. Biochemical tests revealed a very low frequency of the altered acetylcholinesterase mechanism (0.13). Esterase frequencies were high (1). Electrophoresis exposed the B1, A6 and B6 esterase phenotypes.
ESTHER : Bisset_1999_Rev.Cubana.Med.Trop_51_89
PubMedSearch : Bisset_1999_Rev.Cubana.Med.Trop_51_89
PubMedID: 10887566

Title : [Obtention and characterization of murine beta-NGF. Application in a model of cerebral aging] - Castellanos_1998_Rev.Neurol_26_717
Author(s) : Castellanos MR , Moya G , Cruz R , Lorigados L , Fernandez CI , Diaz C , de la Cuetara K , Bergado J , Francis L , Pavon N , Gonzalez E , Ramos R
Ref : Rev Neurol , 26 :717 , 1998
Abstract : INTRODUCTION beta-NGF is a basic protein of 118 aminoacids which acts are a trophic factor for sensory and sympathetic neurons of the peripheral nervous system, and on cholinergic neurons of the anterior basal cerebrum. OBJECTIVES: In view of the functional effect of beta-HGF and its possibilities as a therapeutic agent in neurodegenerative disease, including Alzheimer's disease in this study our aim was to obtain, characterize and show the main results of the application of beta-NGFm in a model of cerebral ageing in rats with cognitive disorders.MATERIAL AND METHODS: For the obtention of beta-NGFm we followed Mobley's method as modified by Ebendal and used mouse submaxillary gland as a source of raw material. The characterization studies were carried out by application of seven techniques which allowed physicochemical characterization and demonstration of the biological activity of the product. Application of beta-NGF obtained under these conditions was carried out in a mode of cerebral ageing and the effects of treatment were assessed by conduct studies, measurement of the activity of the enzyme acetyl cholinesterase and study of neural plasticity. CONCLUSIONS: Characterization studies carried out on the beta-NGFm showed that the protein obtained consists of a mixture of molecules of beta-NGFm which are intact at their extreme N-Terminal, and molecules which have lost the octapeptide of the N-terminal position and show some modification increasing hydrophobicity. All these species were recognized immunologically by the specific antibody anti-NGFm and showed biological activity.
ESTHER : Castellanos_1998_Rev.Neurol_26_717
PubMedSearch : Castellanos_1998_Rev.Neurol_26_717
PubMedID: 9634653

Title : [Determination of insecticide resistance and its biochemical mechanisms in 2 strains of Culex quinquefasciatus from Santiago de Cuba] - Rodriguez_1997_Rev.Cubana.Med.Trop_49_209
Author(s) : Rodriguez MM , Bisset J , Rodriguez I , Diaz C
Ref : Rev Cubana Med Trop , 49 :209 , 1997
Abstract : It was analyzed the behavior of the resistance of 3 organophosphated insecticides (malathion, clorpirifos and methyl-pyrimifos), 3 pyrethroids (deltamethrin, lambda-cyhalothrin and cypermethrin), and 1 carbamate (propuxur) in populations of Culex quinquefasciatus from 2 municipalities of the province of Santiago de Cuba. The values of the resistance factor proved that there is resistance to malathion and clorpirifos. However, in spite of the existence of a high frequency of the mechanisms of elevated esterases and altered acetylcholinesterase no resistance to methylpymirifos, was observed which demonstrated that this insecticide is not affected by these mechanisms selected in our populations of Culex quinquefasciatus. There was resistence to deltamethrin, and lambda-cyhalothrin in Santiago de Cuba, whereas it was moderate to cypermethrin in Santiago and San Luis. Resistance to deltamethrin was also found in San Luis, but it was mild to lambda-cyhalothrin. The results obtained from the use of the synergists S,S,S tributyl phosphotritiade (DBF) and piperonyl butoxide (PB) indicated that the mechanisms of resistance of unspecific esterases and oxidases of multiple function are involved in the resistance to pyrethroids in both strains from Santiago de Cuba and San Luis. It was determined by the biochemical tests that there existed a high frequency of the mechanisms of esterases and altered acetylcholinesterase. The results of the polyacrylamide gel electrophoresis (PAGE) showed that esterase B1 appears more frequently associated with esterases A6 and B6. It was inferred that this association could be connected with the resistance to pyrethroids.
ESTHER : Rodriguez_1997_Rev.Cubana.Med.Trop_49_209
PubMedSearch : Rodriguez_1997_Rev.Cubana.Med.Trop_49_209
PubMedID: 9685989

Title : [The evolution of resistance in a Culex quinquefasciatus strain starting from selection with the pyrethroid insecticide lambdacyhalothrin] - Gonzalez_1996_Rev.Cubana.Med.Trop_48_218
Author(s) : Gonzalez T , Bisset JA , Diaz C , Rodriguez MM , Dieguez L
Ref : Rev Cubana Med Trop , 48 :218 , 1996
Abstract : The resistance change to different insecticides in Culex quinquesfasciatus strain select at the laboratory with doses of pyrethroid lambdacyhalothrin that would cause a larva mortality of 90% were studied. It was attained an increase of the resistance to this insecticide of 144.5 times compared with the original level, and it was obtained a resistant strain (287x). There was an increase of the levels of resistance to methyl-pyrimifos (2.4 times), propoxur (6 times), DDT (5.2 times), clorpirifos (22 time), cypermethrin (67.5 times), and deltamethrin (20.2 times). The frequencies of the genes that codify for the elevated esterases enzymes and for the modified acetylcholinesterase reached their maximum value. Significant changes were observed in the phenotypes for esterases in the electrophoresis in polyacrylamide gels. It was detected synergism of DEF and PB with lambdacyhalothrin. Therefore, the elevated esterases and the esterases of multiple function may contribute to resistance.
ESTHER : Gonzalez_1996_Rev.Cubana.Med.Trop_48_218
PubMedSearch : Gonzalez_1996_Rev.Cubana.Med.Trop_48_218
PubMedID: 9805056

Title : [3 combinations of esterases and their relation with the resistance to organophosphate, carbamate, and pyrethroid insecticides in Culex quinquefasciatus Say, 1823 (Diptera: Culicidae) in Cuba] - Bisset_1996_Rev.Cubana.Med.Trop_48_5
Author(s) : Bisset JA , Dieguez L , Rodriguez MM , Diaz C , Gonzalez T , Vazquez R
Ref : Rev Cubana Med Trop , 48 :5 , 1996
Abstract : The possible relationship between different patterns of esterases and the resistance to various types of insecticides was analyzed by bioassays, biochemical tests, and electrophoresis carried out in a population of Culex quinquefasciatus from Camagey and in three colonies obtained from it by family selection. The original population was heterogeneous and presented 8 combinations of esterases in polyacrylamide gel. A3A6B6, B1B6 and B1A6B6 were the most frequent of them and characterized each selected colony. Every studied colony, including the parental one, showed different levels of resistance to diverse insecticides. Only the resistance to propoxur showed less variation. In every colony it seems to exist a combination of resistance mechanisms; however, the differences found in tests with DEF synergized insecticides show that the different bands of zymograms may represent esterases contributing in a different way to resistance.
ESTHER : Bisset_1996_Rev.Cubana.Med.Trop_48_5
PubMedSearch : Bisset_1996_Rev.Cubana.Med.Trop_48_5
PubMedID: 9768262

Title : [The association of resistance to organophosphate, carbamate and pyrethroid insecticides with the mechanisms of resistance observed in Culex quinquefasciatus strains from Ciudad de La Habana province] - Rodriguez_1995_Rev.Cubana.Med.Trop_47_154
Author(s) : Rodriguez MM , Bisset JA , Mastrapa L , Diaz C
Ref : Rev Cubana Med Trop , 47 :154 , 1995
Abstract : The mechanisms of resistance in Culex quinquefasciatus from 6 municipalities of Havana City were studied in order to determine their genetic frequency. Increased esterases and altered acetylcholinesterase are still being the major resistance mechanisms in Havana City. The mechanisms of esterases is of high frequency, followed by altered acetylcholinestenase. Resistance to cholorpirifos was found for the first time in Culex quinquefasciatus, while resistance of malathion and carbamate propoxur is maintained, and deterioration to pyrethroid susceptibility is being detected. The synergistic effect of S.S.S. trubutyl phosphotritiade (DEF) and piperonil butoxide (PB) was analysed, and it was proven that esterases enzymes and multifunction oxidases are involved in the resistance to pyrethroids. By electrophoresis in polyerylamide gel, it was determined that the combination of esterases that seems to be associated with the resistance to perythroids is B1-A6-B6, which appeared with the greatest percentage. Valves of genetic frequency in the 6 municipalities were found to be high, for both esterase genes and acetylcholinesterase genes (Ache).
ESTHER : Rodriguez_1995_Rev.Cubana.Med.Trop_47_154
PubMedSearch : Rodriguez_1995_Rev.Cubana.Med.Trop_47_154
PubMedID: 9813467

Title : [Resistance to organophosphate, carbamate, and pyrethroid insecticides in Blattella germanica (Dictyoptera: Blattellidae) in 2 municipalities of the City of Havana] - Diaz_1994_Rev.Cubana.Med.Trop_46_130
Author(s) : Diaz C , Bisset JA , Gonzalez T , Rodriguez MM
Ref : Rev Cubana Med Trop , 46 :130 , 1994
Abstract : We determined the resistance of 2 Blattella germanica strains collected in 2 municipalities of City of Havana--Playa (P) and Centro Habana (CH)--to six insecticides: malathion, pyrimiphos-methyl, propoxur, cipermetrine, deltametrine, and lambda cialotrine. The P strain showed resistance only to deltametrine (FR = 80); the CH strain was susceptible to propoxur and lambda cialotrine and resistant to malathion (FR = 12), pyrimiphosmethyl (FR = 13), cipermetrine (FR = 16), and deltametrine (FR = 100). Gene frequency of increased esterases and of the modified acetylcholinesterase was determined in the 2 strains. The values of increased esterases in the two collected strains were: P = 0.90; and CH = 0.91. Values of the modified acetylcholinesterase in the two strains were: P = 0.47; and CH = 0.12.
ESTHER : Diaz_1994_Rev.Cubana.Med.Trop_46_130
PubMedSearch : Diaz_1994_Rev.Cubana.Med.Trop_46_130
PubMedID: 9768250

Title : Malathion and pyrethroid resistance in Culex quinquefasciatus from Cuba: efficacy of pirimiphos-methyl in the presence of at least three resistance mechanisms - Bisset_1991_Med.Vet.Entomol_5_223
Author(s) : Bisset JA , Rodriguez MM , Hemingway J , Diaz C , Small GJ , Ortiz E
Ref : Med Vet Entomol , 5 :223 , 1991
Abstract : Use of malathion for mosquito control in Cuba for 7 years up to 1986 has selected for elevated non-specific esterase and altered acetylcholinesterase (AChE) resistance mechanisms in populations of the pest mosquito Culex quinquefasciatus Say. These mechanisms are still present in relatively high frequencies in the Havana area, despite the replacement of malathion by pyrethroid insecticides for the last 3 years in the mosquito control programme. Samples of Culex quinquefasciatus populations from within a 100 km radius of Havana had high levels of resistance to malathion and lower levels of resistance to propoxur, but there was little or no cross-resistance to the organophosphorus insecticide pirimiphos-methyl. Selection with malathion for twenty-two consecutive generations in the laboratory increased the level of malathion resistance to 1208-fold and propoxur level to 1002-fold, but the maximum level of pirimiphos-methyl resistance was only 11-fold. Pirimiphos-methyl is still operationally effective, despite the resistance mechanisms segregating, so this insecticide if used for control is unlikely to select either of the known resistance factors directly in the field population. Since 1986, pyrethroids have been used extensively, and low levels of pyrethroid resistance were detected in two of five field population samples tested. Malathion selection did not increase the level of pyrethroid resistance, which indicates that one or more distinct pyrethroid resistance factors are now being selected in the field populations of Culex quinquefasciatus.
ESTHER : Bisset_1991_Med.Vet.Entomol_5_223
PubMedSearch : Bisset_1991_Med.Vet.Entomol_5_223
PubMedID: 1768912