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Organophosphate pesticides are widely used in agriculture, leading to soil, water, and food contamination. Among these compounds is Dichlorvos [O,O-dimethyl O-(2,2-dichlorovinyl)phosphate, DDVP], which is listed as a highly toxic compound by the Environmental Protection Agency and World Health Organization. Exposure to DDVP can result in nervous, respiratory, hepatic, and reproductive abnormalities, in addition to endocrine disrupting, mutagenic, and carcinogenic effects. Little is known about the impacts of DDVP on the reprogramming of lipid metabolism, which is also associated with the development and progression of cancer, since the tumor cells need to recruit, capture, and use fatty acids to compose their building membranes. This study aimed to evaluate the influence of the pesticide DDVP on lipid metabolism in the prostate, after chemical induction by the carcinogen N-methyl-N-nitrosourea (MNU). For this, 32 Fischer rats aged 90 days were randomly divided into four experimental groups: Control, DDVP, MNU, and MNU + DDVP. The MNU and MNU + DDVP groups underwent chemical induction with MNU (15 mg/kg) and the DDVP and MNU + DDVP groups received a diet supplemented with DDVP (10 mg/kg). Histopathological analyses of the rat ventral prostate showed 100% incidence of epithelial hyperplasia in the MNU and MNU + DDVP groups. This finding was accompanied by an increase of the epithelial compartment in the MNU + DDVP group. Immunolocalization of important proteins linked to lipid metabolism has been established. In the MNU + DDVP group, Western blotting analyses pointed out an increased expression of the protein LIMP II (Lysosomal Integral Membrane Protein-II), which is correlated with the capture and distribution of lipids in tumor cells. Together, these results indicate that the association of a low dose of DDVP with MNU was able to promote alterations in the morphology and lipid metabolism of the rat ventral prostate, which may be related to tumor progression in this organ.

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BACKGROUND: Pesticides, mainly organophosphates (OP), have been related to increased risk of pemphigus vulgaris (PV) and pemphigus foliaceus (PF), nevertheless, their measurement has not been determined in pemphigus patients. OBJECTIVE: To evaluate pesticide exposure and pesticide measurement, comparing PV, PF and control groups in Southeastern Brazil. METHODS: Information about urban or rural residency and exposure to pesticides at the onset of pemphigus was assessed by questionnaire interview; hair samples from the scalp of PV, PF, and controls were tested for OP and organochlorines (OC) by gas-phase chromatography coupled to mass spectrometry. RESULTS: The minority of PV (2 [7.1%] of 28) and PF (7 [18%] of 39), but none of the 48 controls, informed living in rural areas at the onset of pemphigus (p = 0.2853). PV (33.3%), PF (38.5%), and controls (20%) informed exposure to pesticides (p = 0.186). Twenty-one (14.8%) of 142 individuals tested positive for OP and/or OC: PV (2 [6.3%] of 32) and PF (11 [25.6%] of 43) had similar pesticides contamination as controls (8 [11.9%] of 67) (p = 0.4928; p = 0.0753, respectively), but PF presented higher contamination than PV (p = 0.034). PV did not present any positivity for OP. Three (7%) PF tested positive for both OP and OC. Some PF tested positive for three or four OP, mainly diazinon and dichlorvos. STUDY LIMITATION: Lack of data for some controls. CONCLUSION: Although the frequency of PV and PF patients exposed to pesticides was similar, pesticides were more frequently detected in hair samples from PF compared to PV. The cause-effect relationship still needs to be determined.

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Abstract Background Pesticides, mainly organophosphates (OP), have been related to increased risk of pemphigus vulgaris (PV) and pemphigus foliaceus (PF), nevertheless, their measurement has not been determined in pemphigus patients. Objective To evaluate pesticide exposure and pesticide measurement, comparing PV, PF and control groups in Southeastern Brazil. Methods Information about urban or rural residency and exposure to pesticides at the onset of pemphigus was assessed by questionnaire interview; hair samples from the scalp of PV, PF, and controls were tested for OP and organochlorines (OC) by gas-phase chromatography coupled to mass spectrometry. Results The minority of PV (2 [7.1%] of 28) and PF (7 [18%] of 39), but none of the 48 controls, informed living in rural areas at the onset of pemphigus (p = 0.2853). PV (33.3%), PF (38.5%), and controls (20%) informed exposure to pesticides (p = 0.186). Twenty-one (14.8%) of 142 individuals tested positive for OP and/or OC: PV (2 [6.3%] of 32) and PF (11 [25.6%] of 43) had similar pesticides contamination as controls (8 [11.9%] of 67) (p = 0.4928; p = 0.0753, respectively), but PF presented higher contamination than PV (p = 0.034). PV did not present any positivity for OP. Three (7%) PF tested positive for both OP and OC. Some PF tested positive for three or four OP, mainly diazinon and dichlorvos. Study limitation Lack of data for some controls. Conclusion Although the frequency of PV and PF patients exposed to pesticides was similar, pesticides were more frequently detected in hair samples from PF compared to PV. The cause-effect relationship still needs to be determined.

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The literature has been shown that exposition by inhalation to chemical compounds can cause vocal disorders and dysphagia in humans, in addition to other symptoms that are manifested according to the type, concentration and duration of exposure to the substance. Cypermethrin and dichlorvos are pesticides widely used in agriculture, public health, veterinary, and home environments. Despite the scientific evidence that cypermethrin and dichlorvos can cause neurodegenerative damage and motor alterations, there are no studies evaluating the toxic effects of these pesticides on the morphology of structures responsible for vocal mobility, especially to the Recurrent Laryngeal Nerve (RLN). Considering the association between vocal disorders in humans and variations in RLN and morphometry, the aim of this study was to evaluate the possible alterations in the microstructure of RLN secondary to subchronic exposure to cypermethrin (pyrethroid) and dichlorvos (organophosphate) in Wistar rats. The experimental protocol (approved by CEUA-UFCSPA: 321/15 and 323/15) consisted of 15 male Wistar rats, allocated in 3 groups: Control (n = 5, exposed to water), Cypermethrin (n = 5, exposed to cypermethrin - 1/10 of the inhalation median lethal concentration [LC50] - 0.25 mg/L) and dichlorvos (n = 5, exposed to dichlorvos - 1/10 of the LC50 - 1.5 mg/L). Inhalation exposure was performed for 4 hours, 5 times per week, for 6 weeks. The nerves were collected, histologically processed and analyzed using morphometric parameters measured using ZEN 2.6 (Zeiss - Germany). The cypermethrin and dichlorvos groups showed significant changes (P < 0.001, ANOVA) in the g-ratio and in the thickness of the myelin sheath of the RLN when compared to the control animals, however, none of the other parameters evaluated showed statistically significant differences. These findings indicate that repeated inhalation exposure to commercial products of cypermethrin and dichlorvos is able to modify the structure of the RLN and possibly generating vocal changes and / or dysphagia.

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In forensic toxicology, the detection of toxic chemicals from human bone marrow is often used in cases with an extended post mortem interval; however, in veterinary medicine, this practice is not used. Therefore, this study was performed to investigate the suitability of bone marrow for toxicological analysis in dogs and cats. Six animals with suspected poisoning were selected; the carcasses were sent for necropsy, and the organs were collected and preserved in buffered formalin and processed routinely for histological examination. In addition, bone marrow samples from the femur, humerus, and tibia were collected for toxicological analysis by liquid chromatography coupled to mass spectrometry detection (LC-MS). This analysis confirmed the presence of aldicarb, aldicarb sulfone, asulam, carbendazim, chlorpyrifos, dichlorvos, thifensulfuron methyl and trifloxysulfuron-sodium and associated with clinical symptoms and anatomo-histopathological alterations it was recognized the poisonings. It is expected that this study will promote the toxicological investigation of bone marrow and open avenues for the use of this tissue as an option for the detection of toxic chemicals in cases of forensic pathology.(AU)

Na toxicologia forense, a detecção de substâncias químicas tóxicas provenientes da medula óssea humana é frequentemente usada em casos com intervalo post mortem prolongado; no entanto, na medicina veterinária, essa prática não é utilizada. Portanto, este estudo foi realizado para investigar a utilização da medula óssea nas análises toxicológicas em cães e gatos. Seis animais com suspeita de intoxicação foram selecionados; as carcaças foram enviadas para necropsia e os órgãos foram coletados e preservados em formalina tamponada e processados rotineiramente para exame histológico. Amostras de medula óssea de fêmur, úmero e tíbia foram coletadas para análise toxicológica por cromatografia líquida acoplada à espectrometria de massa-massa (LC-MS). A análise por LC-MS confirmou a presença dos agrotóxicos aldicarbe, aldicarbe sulfona, asulam, carbendazim, clorpirifós, diclorvós, tifensulfuron metil e trifloxisulfuron-sódico, e em associação com sinais clínicos e achados anatomo-histopatológicos comprovou-se as intoxicações. Espera-se que este estudo promova a utilização da medula óssea como uma opção na investigação toxicológica para a detecção de produtos químicos tóxicos em casos de patologia forense.(AU)

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RESUMO

In forensic toxicology, the detection of toxic chemicals from human bone marrow is often used in cases with an extended post mortem interval; however, in veterinary medicine, this practice is not used. Therefore, this study was performed to investigate the suitability of bone marrow for toxicological analysis in dogs and cats. Six animals with suspected poisoning were selected; the carcasses were sent for necropsy, and the organs were collected and preserved in buffered formalin and processed routinely for histological examination. In addition, bone marrow samples from the femur, humerus, and tibia were collected for toxicological analysis by liquid chromatography coupled to mass spectrometry detection (LC-MS). This analysis confirmed the presence of aldicarb, aldicarb sulfone, asulam, carbendazim, chlorpyrifos, dichlorvos, thifensulfuron methyl and trifloxysulfuron-sodium and associated with clinical symptoms and anatomo-histopathological alterations it was recognized the poisonings. It is expected that this study will promote the toxicological investigation of bone marrow and open avenues for the use of this tissue as an option for the detection of toxic chemicals in cases of forensic pathology.(AU)

Na toxicologia forense, a detecção de substâncias químicas tóxicas provenientes da medula óssea humana é frequentemente usada em casos com intervalo post mortem prolongado; no entanto, na medicina veterinária, essa prática não é utilizada. Portanto, este estudo foi realizado para investigar a utilização da medula óssea nas análises toxicológicas em cães e gatos. Seis animais com suspeita de intoxicação foram selecionados; as carcaças foram enviadas para necropsia e os órgãos foram coletados e preservados em formalina tamponada e processados rotineiramente para exame histológico. Amostras de medula óssea de fêmur, úmero e tíbia foram coletadas para análise toxicológica por cromatografia líquida acoplada à espectrometria de massa-massa (LC-MS). A análise por LC-MS confirmou a presença dos agrotóxicos aldicarbe, aldicarbe sulfona, asulam, carbendazim, clorpirifós, diclorvós, tifensulfuron metil e trifloxisulfuron-sódico, e em associação com sinais clínicos e achados anatomo-histopatológicos comprovou-se as intoxicações. Espera-se que este estudo promova a utilização da medula óssea como uma opção na investigação toxicológica para a detecção de produtos químicos tóxicos em casos de patologia forense.(AU)

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Dichlorvos (2,2-dichlorovinyl-dimethylphosphate), an organophosphorus pesticide used for indoor insect and livestock parasite control, is among the most common commercially available pesticides. However, there are significant concerns over its toxicity, especially due to its relative stability in water, soil, and air. Zebrafish, an important developmental model, has been used for studying the effects of toxic compounds. The aim of this study was to evaluate the exposure to dichlorvos at early life stages (1 h postfertilization - 7 days postfertilization) in the zebrafish and its toxicological effects during the development, through morphological (7 days postfertilization), locomotor and social behavior analysis (7, 14, 30, 70, and 120 days postfertilization). Dichlorvos (1, 5, and 10 mg/L) exposure reduced the body length and heartbeat rate at 7 days postfertilization (dpf), as well as the surface area of the eyes (5 and 10 mg/L). The avoidance behavior test showed a significant decrease in escape responses at 7 (1, 5, and 10 mg/L) and 14 (5 and 10 mg/L) dpf zebrafish. The evaluation of larval exploratory behavior showed a reduction in distance traveled, mean speed (1, 5, and 10 mg/L) and time mobile (10 mg/L) between control and dichlorvos groups. In addition, the analysis performed on adult animals showed that the changes in distance traveled and mean speed remained reduced in 30 (1, 5, and 10 mg/L) and 70 dpf (5 and 10 mg/L), recovering values similar to the control at 120 dpf. The social behavior of zebrafish was not altered by exposure to dichlorvos in the early stages of development. Thus, the exposure to organophosphorus compounds at early stages of development induces an increased susceptibility to behavioral and neuronal changes that could be associated with several neurodegenerative diseases.

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Acylpeptide hydrolase (APEH) is a serine hydrolase that displays two catalytic activities, acting both as an exopeptidase toward short N-acylated peptides and as an endopeptidase toward oxidized peptides or proteins. It has been demonstrated that this enzyme can degrade monomers, dimers, and trimers of the Aß1-40 peptide in the conditioned media of neuroblastoma cells. In a previous report, we showed that the specific inhibition of this enzyme by the organophosphate molecule dichlorvos (DDVP) triggers an enhancement of long-term potentiation in rat hippocampal slices. In this study, we demonstrate that the same effect can be accomplished in vivo by sub-chronic treatment of young rats with a low dose of DDVP (0.1 mg/kg). Besides exhibiting a significant enhancement of LTP, the treated animals also showed improvements in parameters of spatial learning and memory. Interestingly, higher doses of DDVP such as 2 mg/kg did not prove to be beneficial for synaptic plasticity or behavior. Due to the fact that at 2 mg/kg we observed inhibition of both APEH and acetylcholinesterase, we interpret that in order to achieve positive effects on the measured parameters only APEH inhibition should be obtained. The treatment with both DDVP doses produced an increase in the endogenous concentration of Aß1-40, although this was statistically significant only at the dose of 0.1 mg/kg. We propose that APEH represents an interesting pharmacological target for cognitive enhancement, acting through the modulation of the endogenous concentration of Aß1-40.

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The current work evaluated the inhibitory potency of the herbicide glyphosate (GLP) on acetylcholinesterase (AChE) activity in male and female rat tissues. The AChE activity in brain was higher (p<0.05) than those observed in kidney (females: 2.2-fold; males: 1.9-fold), liver (females: 6-fold; males: 6.9-fold) and plasma (females: 14.7-fold; males: 25.3-fold). Enzyme activities were higher in presence of 10mM GLP compared to those measured at an equimolar concentration of the potent AChE inhibitor dichlorvos (DDVP). Moreover, IC50s for GLP resulted between 6×10(4)- and 6.8×10(5)-fold higher than those observed for DDVP. In conclusion, GLP is a weak inhibitor of AChE in rats.

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The number of studies emphasizing the possible damage that acaricidal spray formulations can cause on engorged female ticks' reproductive parameters is small. The present study evaluated the deleterious effects of a spray formulation (dichlorvos 60% + chlorpyrifos 20%) on the reproductive parameters of a susceptible population of Rhipicephalus (B.) microplus females, using the Stall Test. The ticks were allocated randomly to treatments according to the mean numbers of females detached from each cow on days -3, -2 and -1 and the cattle pen location. The numbers of engorged female ticks that naturally detached from the cattle were counted daily from day 1 to day 30. For each group, 20 detached engorged female ticks or the available number collected daily were evaluated regarding reproductive parameters. Associations of organophosphates demonstrated elevated acaricidal efficacy, as well as deleterious effects on the reproductive parameters of R. (B.) microplus females. The engorged female weight (days 1 to 7), weight of egg masses (days 5 to 10) and larval hatching percentage (days 5 to 19) were decreased (P ≤ 0.05). It is possible that a formulation can lead to deleterious effects on R. (B.) microplus females when the tick population analyzed shows elevated sensitivity towards a particular formulation. However, further studies need to be conducted.

É relativamente pequeno o número de estudos que enfatiza os danos que uma formulação acaricida spray pode desencadear sobre os parâmetros reprodutivos das teleóginas. O presente estudo teve como objetivo avaliar os efeitos deletérios de uma formulação spray comercial (dichlorvos 60% + Clorpirifós 20%), sobre os parâmetros reprodutivos de uma população susceptível de R. (B.) microplus, desprendidas de bovinos experimentalmente infestados, utilizandose o teste de estábulo. Os animais foram alocados aos grupos de tratamentos de acordo com a contagem média de fêmeas desprendidas dos bovinos nos dias -3, -2 e -1. O número de teleóginas desprendidas foi quantificado do dia 1 ao 30. Para cada grupo, diariamente 20 fêmeas, ou a quantidade disponível, foram selecionadas e submetidas à avaliação dos parâmetros reprodutivos. A associação de organofosforados demonstrou elevada eficácia acaricida e também apresentou efeitos deletérios sob os parâmetros reprodutivos de Rhipicephalus (B.) microplus, diminuindo (P≤0,05) o peso das teleóginas (dos dias 1 ao 7), o peso da massa de ovos (dos dias 5 ao 10) e a eclodibilidade das larvas (dos dias 5 ao 19). Talvez uma formulação pode apresentar efeitos deletérios sobre os parâmetros reprodutivos de fêmeas de R. (B.) microplus, quando existe um elevado grau de sensibilidade dessa cepa de carrapato a um determinado composto. De qualquer maneira, futuros estudos devem ser realizados.

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RESUMO

The number of studies emphasizing the possible damage that acaricidal spray formulations can cause on engorged female ticks' reproductive parameters is small. The present study evaluated the deleterious effects of a spray formulation (dichlorvos 60% + chlorpyrifos 20%) on the reproductive parameters of a susceptible population of Rhipicephalus (B.) microplus females, using the Stall Test. The ticks were allocated randomly to treatments according to the mean numbers of females detached from each cow on days -3, -2 and -1 and the cattle pen location. The numbers of engorged female ticks that naturally detached from the cattle were counted daily from day 1 to day 30. For each group, 20 detached engorged female ticks or the available number collected daily were evaluated regarding reproductive parameters. Associations of organophosphates demonstrated elevated acaricidal efficacy, as well as deleterious effects on the reproductive parameters of R. (B.) microplus females. The engorged female weight (days 1 to 7), weight of egg masses (days 5 to 10) and larval hatching percentage (days 5 to 19) were decreased (P ≤ 0.05). It is possible that a formulation can lead to deleterious effects on R. (B.) microplus females when the tick population analyzed shows elevated sensitivity towards a particular formulation. However, further studies need to be conducted.

É relativamente pequeno o número de estudos que enfatiza os danos que uma formulação acaricida spray pode desencadear sobre os parâmetros reprodutivos das teleóginas. O presente estudo teve como objetivo avaliar os efeitos deletérios de uma formulação spray comercial (dichlorvos 60% + Clorpirifós 20%), sobre os parâmetros reprodutivos de uma população susceptível de R. (B.) microplus, desprendidas de bovinos experimentalmente infestados, utilizandose o teste de estábulo. Os animais foram alocados aos grupos de tratamentos de acordo com a contagem média de fêmeas desprendidas dos bovinos nos dias -3, -2 e -1. O número de teleóginas desprendidas foi quantificado do dia 1 ao 30. Para cada grupo, diariamente 20 fêmeas, ou a quantidade disponível, foram selecionadas e submetidas à avaliação dos parâmetros reprodutivos. A associação de organofosforados demonstrou elevada eficácia acaricida e também apresentou efeitos deletérios sob os parâmetros reprodutivos de Rhipicephalus (B.) microplus, diminuindo (P≤0,05) o peso das teleóginas (dos dias 1 ao 7), o peso da massa de ovos (dos dias 5 ao 10) e a eclodibilidade das larvas (dos dias 5 ao 19). Talvez uma formulação pode apresentar efeitos deletérios sobre os parâmetros reprodutivos de fêmeas de R. (B.) microplus, quando existe um elevado grau de sensibilidade dessa cepa de carrapato a um determinado composto. De qualquer maneira, futuros estudos devem ser realizados.

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Organophosphate (OP) pesticides such as dichlorvos (DDVP) intoxication has been shown to produce oxidative stress due to the generation of free radicals, which alter the antioxidant defense system in erythrocytes. In this study, the effects of DDVP (1, 10, 100 µM) or DDVP + vitamin C (VC; 10 µM) or vitamin E (VE; 30 µM), on the levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in human erythrocytes were examined in vitro. There were no statistical differences between all groups for 1 µM concentration of DDVP. Treatment with DDVP alone produced an increase in the level of MDA and decreased activities of antioxidant enzymes (P < 0.05). Groups treated with vitamins and DDVP showed protective effects of vitamins against DDVP-induced changes in antioxidant enzyme activity and lipid peroxidation (LPO) (10 µM). At 100 µM concentration of DDVP vitamins had no effect on DDVP-induced toxicity. The results show that administration of DDVP resulted in the induction of erythrocyte LPO and alterations in antioxidant enzyme activities, suggesting that reactive oxygen species (ROS) may be involved in the toxic effects of DDVP. Also the data show that the plasma level of VC and VE may ameliorate OP-induced oxidative stress by decreasing LPO in erythrocytes at certain doses of OP pesicides.

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Os inseticidas de uso domissanitário são utilizados para proteger o ambiente urbano. Porém, esses produtos propiciam risco à saúde. Neste experimento preliminar foi avaliado o grau de efeito tóxico em ratos, após a exposição inalatória ao diclorvós, um inseticida de uso domissanitário, em ambiente sem ventilação. O inseticida foi pulverizado no interior de uma câmara de vidro e os ratos foram expostos durante 6 e 24 h. A atividade da colinesterase plasmática foi analisada antes e após a exposição. O efeito da exposição inalatória refletiu-se sobre a depressão enzímica em até 37%. A permanência em ambiente sem ventilação ou arejamento por maior tempo acarretou maior grau de intoxicação.(AU)

Household insecticides are used for protecting the urban environment. However, these product might cause health risk. This preliminary study aimed at evaluating the toxic effects of an insecticide for household use (dichlorvos) in rats by inhalation exposure in an unventilated environment. The insecticide was sprayed inside a glass chamber and the rats were exposed for 6 and 24 hours. The plasma cholinesterase activity was analyzed before and after the exposure. The effect of inhalation was reflected on the enzyme depression in association with the exposure length of time. The permanence in the environment without ventilation, for longer time, resulted in higher degreed of intoxication.(AU)

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The properties of poly(4-aminophenol) modified graphite electrode as material for the immobilization of acetylcholinesterase were investigated by the Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Atomic Force Microscopy. The polymer was deposited on graphite electrode surface by the oxidation of 4-aminophenol and then acetylcholinesterase was immobilized on the surface of the electrode. The biosensor coupled in the continuous flow system was employed for the detection of dichlorvos. The detection and quantification limits were 0.8 and 2.4 μmol L-1 dichlorvos, respectively. Graphite electrodes modified with the poly(4-aminophenol) showed to be an efficient and promising material for immobilization of acetylcholinesterase enzyme. The proposed method requires simple parts which are easy to build, involves only one biosensor and the potentiometric detection is simple.

RESUMO

The histopathological effects of dichlorvos, an organophosphate pesticide, on the gill and liver tissues in Cirrhinus mrigala were determined by light microscopy. The fishes were exposed to sublethal concentrations (0.91 and 1.82 ppm) of dichlorvos for 10 days with parallel untreated control. No histopathological effects were observed in control group. Hyperplasia, desquamation, and necrosis of epithelial, epithelial lifting, oedema, lamellar fusion, collapsed secondary lamellae, curling of secondary lamellae and aneurism in the secondary lamellae were observed in gill tissues exposed to dichlorvos. Hepatic lesions in the liver tissues of fishes exposed to dichlorvos were characterized by cloudy swelling of hepatocytes, congestion, vacuolar degeneration, karyolysis, karyohexis, dilation of sinusoids and nuclear hypertrophy.

RESUMO

The effectiveness and persistence of Ectofarma* in the control of B. microplus and D. hominis larvae were evaluated. Initially, the effect on estimated reproduction and percentage of reduction was determined by dipping female ticks in 1:400 diluted solution of the product. The percentage of reduction was 95.34, and the reduction on hatchability of larvae was 100%. Then, in a field trial the product, in the same dilution, was handsprayed over a group of nine bovines. The number of ticks on treated and untreated animals were counted on days 0 ,1 ,2 ,3 ,7 ,1 4 ,2 1 , 28, 35 and 42 after treatment. D. hominis larvae were counted on day 3 and further, weekly, until the sixth week. The efficacy in vitro of Ectofarma" on the hatchability of B. microplus eggs was 100%. In the field trial this product was highly effective against ticks during 3 weeks, and ticks mean number on the treated group was lower than on control one, until thefourth week after treatment. Reduction of D.hominis larvae reached 65% on the third day post-treatment, and mean number of larvae in treated animals was always lower than the amount found in untreated ones.

Testou-se a sensibilidade da cepa de B. microplus do campus de Pirassununga da USP ao Ectofarma®, na diluição 1:400 através dobiocarrapaticidograma. A ovipostura no grupo tratado (A) foi reduzida em 95,34%, em relação ao grupo-controle (B) e a eclosão de larvas provenientes dos ovos do grupo B foi de 100%, enquanto no grupo A não ocorreu eclosão. Diante desse resultado, efetuou-se o teste a campo, utilizando dois grupos de nove bovinos mestiços. No dia 0 os números médios de B. microplus a 5 mm e de bernes nos animais dos dois grupos eram estatisticamente iguais. Os bovinos do grupo A foram aspergidos com o produto na mesma diluição utilizada no teste in vitro. Os carrapatos foram contados nos dias 1, 2, 3, 7, 14, 21, 28, 35 e 42 e os bernes no 3fi dia pós-tratamento (dpt) e depois, semanalmente, até a 68 semana. Houve redução drástica no número médio de carrapatos do grupo A do primeiro ao 210 dpt, aumentando a partir de 28® dpt. A redução do número médio de larvas de D. hominis chegou a 65% no 35 dpt, nos animais do grupo tratado, e embora a eficácia do produto tenha sido baixa, o número médio de bernes no grupo A foi sempre menor do que no grupo B, após o tratamento.

RESUMO

The effectiveness and persistence of Ectofarma* in the control of B. microplus and D. hominis larvae were evaluated. Initially, the effect on estimated reproduction and percentage of reduction was determined by dipping female ticks in 1:400 diluted solution of the product. The percentage of reduction was 95.34, and the reduction on hatchability of larvae was 100%. Then, in a field trial the product, in the same dilution, was handsprayed over a group of nine bovines. The number of ticks on treated and untreated animals were counted on days 0 ,1 ,2 ,3 ,7 ,1 4 ,2 1 , 28, 35 and 42 after treatment. D. hominis larvae were counted on day 3 and further, weekly, until the sixth week. The efficacy in vitro of Ectofarma" on the hatchability of B. microplus eggs was 100%. In the field trial this product was highly effective against ticks during 3 weeks, and ticks mean number on the treated group was lower than on control one, until thefourth week after treatment. Reduction of D.hominis larvae reached 65% on the third day post-treatment, and mean number of larvae in treated animals was always lower than the amount found in untreated ones.

Testou-se a sensibilidade da cepa de B. microplus do campus de Pirassununga da USP ao Ectofarma®, na diluição 1:400 através dobiocarrapaticidograma. A ovipostura no grupo tratado (A) foi reduzida em 95,34%, em relação ao grupo-controle (B) e a eclosão de larvas provenientes dos ovos do grupo B foi de 100%, enquanto no grupo A não ocorreu eclosão. Diante desse resultado, efetuou-se o teste a campo, utilizando dois grupos de nove bovinos mestiços. No dia 0 os números médios de B. microplus a 5 mm e de bernes nos animais dos dois grupos eram estatisticamente iguais. Os bovinos do grupo A foram aspergidos com o produto na mesma diluição utilizada no teste in vitro. Os carrapatos foram contados nos dias 1, 2, 3, 7, 14, 21, 28, 35 e 42 e os bernes no 3fi dia pós-tratamento (dpt) e depois, semanalmente, até a 68 semana. Houve redução drástica no número médio de carrapatos do grupo A do primeiro ao 210 dpt, aumentando a partir de 28® dpt. A redução do número médio de larvas de D. hominis chegou a 65% no 35 dpt, nos animais do grupo tratado, e embora a eficácia do produto tenha sido baixa, o número médio de bernes no grupo A foi sempre menor do que no grupo B, após o tratamento.