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PubMed1971

Structure-activity relationships for insecticidal carbamates.

Carbamate insecticides are biologically active because of their structural complementarity to the active site of acetylcholinesterase (AChE) and their consequent action as substrates with very low turnover numbers. Carbamates behave as synthetic neurohormones that produce their toxic action by interrupting the normal action of AChE so that acetylcholine accumulates at synaptic junctions. The necessary properties for a suitable insecticidal carbamate are lipid solubility, suitable structural complementarity to AChE, and sufficient stability to multifunction-oxidase detoxification. The relationships between the structure and the activity of a large number of synthetic carbamates are analysed in detail, with particular attention to the second of these properties.

Binding Sites↗
PubMed1975

[Pollution of human milk in France by organochlorine insecticide residues].

The monthly analysis of milk mixtures from ten French human milk banks, over a period of two years, showed that there was marked pollution by organochlorine insecticide residues. The following averages were noted: hexachlorocyclohexane + hexachlorobenzene 2,75 mg/kg of pure fat, DDT and derivatives 3,24 mg/kg fat, heptachlor epoxide 0,28, dieldrin 0,23. The main insecticides were, with average values, beta hexachlorocyclohexane (1,67), hexachlorobenzene (0,98), and dichlorodiphenyldichloroethylene (2,40). All these milks were invariably very polluted throughout the year, but there were however noted some qualitative differences according to the geographic position of the milk banks: South of the Loire river, the main polluting factor was hexachlorocyclohexane, whilst North of the Seine, fairly high values were found for heptachlor epoxide and dieldrin. The special study of human milk from Lille showed a 50% reduction in pollution between 1970 and 1973. The probable routes of contamination are human food and the ill-advised domestic use of pesticides.

Algeria↗
PubMed1977

Organochlorine insecticide residues in field soils of the Kitakyushu district--Japan 1970-74.

Residues of organochlorine insecticides were monitored in field soils of the Kitakyushu District, Japan, from 1970 to 1974, before and after the insecticides were banned from agricultural fields. The arithmetic mean (AM) and geometric mean (GM) of BHC reached maximum levels in 1970 and 1971, then decreased rapidly during 1972 and 1974. Among BHC isomers, beta-BHC had highest mean levels and was therefore thought to be the most persistent of the isomers in field soils. Residues of aldrin, dieldrin, and endrin peaked in 1970 and/or 1971, and then decreased yearly. The percentage of sites which had aldrin contamination have decreased; those with dieldrin contamination have increased. Mean values of p,p'-DDE, p,p'-DDT, and sigmaDDT declined more slowly than did BHC and cyclodienes. Values of DDT and its related compounds were higher than were those of BHC, aldrin, dieldrin, and endrin. The residues of p,p'-DDE were most frequently detected of the DDT compounds.

Chromatography, Gas↗
PubMed1977

[Rapid gas chromatographic method of determining organochlorine insecticides in human fatty tissue].

A prompt, readily executed method for chlororganic insecticides determination in human fatty tissue is developed. The analytical course includes sample extraction with hexane, liquid distributional extraction with acetonitrile, and purification through small aluminium dioxide column. Final determination is performed with gas-liquid chromatography using electron detector. The method is endowed with a very high sensibility ranging from 0.1 micron/kg for hexachlorcyclohexane to 0.8 micron/kg for methoxychlor. Attained is a mean analytical yield for heptachlorepoxide amounting to 94 per cent. Reproducibility is fully satisfactory at interval of dispersion of the single measurement 9 per cent; confidential interval of the mean - 3 per cent. The method is successfully applied in mass investigations of the general population for level of chlororganic insecticides' determination.

Adipose Tissue↗
PubMed1977

Resistant levels of houseflies to six kinds of synthetic insecticides in the Philippines.

The resistant levels of houseflies to six kinds of insecticides: DDT, Pyrethrins, malathion, Sumithion, Baytex and DDVP, were examined on 15 strains collected in the Philippines. It was found that most housefly colonies in the Philippines showed higher susceptibility to those insecticides than the Takatsuki strains, especially to DDT. The range of LD50 values to malathion were between 1.775 microgram and 0.0975 microgram per fly. Among 15 strains collected in the Philippines, 7 showed higher LD50 values to malathion than the Takatsuki strain. These values mean that the houseflies in the Philippines are increasing their resistance to malathion.

Animals↗
PubMed1980

Effect of insecticide (BHC) on brain neurosecretory cells of Poekilocerus pictus (Acrididae).

Neurosecretory cells in the adult males and females of Poekilocerus pictus were studied. They were found in forebrain and hand brain regions in the form of small patches. The median group of pars intercerebralis is however a big patch of about 100...110 cells. The brain neurosecretory cells of Poekilocerus pictus could be differentiated into two types on the basis of their staining reaction i.e. A and B types. The A type cells are restricted to only the median group whereas the other groups have only the B type cells. Effect of 0.01% BHC (LD 50 dose), an organic insecticide was studied. Four incubation periods viz. 1 h, 3 1/2 h, 6 h and 24 hours were tried. the insecticide acted as inducer to the triggering mechanism of enhanced secretory activity and with prolonged incubation a complete exhaustion of secretory material accompanied with lot of disruptions and disturbances to the compactness of the neurosecretory cell wall occurred.

Animals↗
PubMed1980

Effect of Insecticide (BHC) on the neurosecretory cells of ventral nerve cord of adult Poekilocercus pictus (Acrididae).

Neurosecretory cells have been observed in all the ganglia of the ventral nerve cord of Poekilocerus pictus. In the suboesophageal ganglion they could be differentiated into 2 types on the basis of their staining reaction, but neurosecretory cells of all the other ganglia stain similarly. Effect of an organic insecticide BHC was observed on the neurosecretory cells of all the locations in the ventral nerve cord. Initially the insecticide acts to trigger the secretory activity but a prolonged action leads to a complete exhaustion of the secretory material which is also accompanied with many cytomorphological alterations such as loss of turgidity and compactness of the cells and appearance of undulations and sometimes complete rupture of the cell wall.

Animals↗
PubMedDate not supplied

Mode of action of lindane, dieldrin and related insecticides in the central nervous system.

A mode of action for lindane, dieldrin and related chlorinated hydrocarbon insecticides is proposed. The available evidence suggests that these insecticides act upon neurons in a global manner. Their primary target is the synapse, and they act there to intensify synaptic activity, primarily by enhancing transmitter release from the presynaptic terminal. All neurons appear to be affected. There is no apparent predilection for excitatory or inhibitory systems in the nervous system nor is there evidence for a specific action upon a single neurotransmitter or neurotransmitter system. It is proposed that the modifications that occur in behavior are based upon this same mode of action. A simplified model of brain plasticity, the kindled seizure model, is described as a potential tool for further investigation.

Animals↗
PubMed1981

[Comparative study of the mutagenic activity of organophosphate insecticides on bacteria].

Mutagenic activity of the organo-phosphorus insecticides, metaphos, phosphamide and carbophos, on indicator Salmonella typhimurium TA-1535 strain is shown which is determined without metabolic activation. It is established that all the three preparations induce direct mutations in Pseudomonas aeruginosa. The quantity of visible mutations increases with the prolongation of exposure time and the insecticide concentration. Metaphos and phosphamide induced auxotrophic mutations. Phosphamide has the highest mutagenic activity in the assays with bacterial systems.

Bacteria↗
PubMed1980

[Comparative studies of methods for determining organochlorine insecticides and polychlorinated biphenyls].

The polychlorinated biphenyls are chemical compounds that are similar in their structure and properties to the chlororganic insecticides of the DDT group. The working out of a method for their analysis is important for the veterinary and sanitary inspection of food products of animal origin. Tested were as many as six column-chromatographic methods for the separation of standard solutions of polychlorinated biphenyls (Chlophen A 50 and Chlophen A30) and some chlororganic insecticides. A modified method, based on the method of Snyder et al. was suggested for the separation of these compounds. Much less time was used with it for analysis, and a better reproduction was achieved of the eluted compounds.

Animals↗
PubMedDate not supplied

Anticholinesterase insecticide poisoning.

Anticholinesterase insecticides can be lethal, especially to small children. Prevention, not treatment, is the key to lowering the mortality rate. However, treatment, when necessary, can be effective if the poisoning agent is identified quickly as an anticholinesterase insecticide and therapy is begun immediately and aggressively. Large doses (up to 5 gm) of atropine, which block the parasympathetic effects of the poison, in conjunction with pralidoxime, a cholinesterase regenerator, need to be administered, second only in priority to establishing an airway. The second line of attack after adequate atropinization is supportive. Assistance with ventilation is individualized according to the degree of patient need. Intake with cautiously vigorous fluid therapy and output via Foley catheter are essential. Gastric lavage, seizure precautions and control as necessary, good body hygiene, and frequent turning are also part of necessary nursing intervention. Prognosis is fairly good if improvement is shown after therapy is begun. Maintaining adequate atropinization seems to be difficult yet essential to the success of the treatment and a good prognosis for the patient.

Accident Prevention↗
PubMed1982

[Acaricidal, chemosterilant and insecticidal activity of triazine derivatives].

A large number of 1-aryl-3,3-dialkyl triazenes and 1,2-diphenyl triazenes variously substituted in the 3 position with OH and alkyl groups were prepared and studied for acaricide activity against Panonychus ulmi and chemosterilizing and insecticidal activity against Musca domestica. The results highlighted the marked chemosterilizing activity of 1-(2-methoxyphenyl)-3,3-di-n-propyltriazene and the interesting acaricidal activity of 1-(4-benzoylphenyl)-3,3-dimethyltriazene. The examination of such a large number of compounds for insecticidal activity allowed interesting conclusions to be drawn regarding structure/activity relationships.

Acari↗
PubMed1982

Serum levels of organochlorine insecticides in humans in Sao Paulo, Brazil.

Residues of organochlorine insecticides were determined by gas chromatograph-electron capture detector in two population groups: one (n = 21) formed by persons living in the neighborhood of a technical HCH (hexachlorocyclohexane) factory and the other (n = 21) constituted of individuals from the general population not occupationally exposed to pesticides. No difference was observed in the serum insecticide levels of the two groups. In the 42 samples, alpha-HCH was observed in 42 (means 1.2 micrograms/L), gamma-HCH was observed in 38 (means 0.4 microgram/L), beta-HCH was observed in 42 (means 7.3 micrograms/L), delta-HCH was observed in 4 (means greater than 0.3 micrograms/L), aldrin was observed in 42 (means 1.4 micrograms/L), p, p'DDE was observed in 42 (means 23.9 micrograms/L), o, p' -DDT was observed in 11 (means less than 0.2 micrograms/L), p,p' -DDD was observed in 32 means 2.1 micrograms/L) and p, p' -DDT was observed in 38 (means 2.1 micrograms/L).

Adult↗
PubMed1980

Gas-liquid chromatographic determination of organophosphorus insecticide residues in fruits and vegetables.

A method intended for regulatory purposes is described for the determination of organophosphorus insecticide residues in fruits and vegetables. Eighteen organophosphorus insecticides, azinphos-ethyl, chlorpyrifos, diazinon, dichlorvos, dimethoate, ethion, ethoate-methyl, fenitrothion, fenthion, formothion, malathion, methidathion, mevinphos, parathion, phosalone, phosphamidon, thiometon, and trichlorphon, and 7 metabolites, fenitrooxon, fenthion sulfoxide, fenthion sulfone, malaoxon, desethylphosphamidon, thiometon sulfoxide, and thiometon sulfone, were extracted from different crops with acetone and partitioned into hexane or ethyl acetate, according to their polarities. The hexane extract was cleaned up by eluting from a Florisil column with acetone-hexane (4+96). The ethyl acetate extract needs no cleanup. The concentrated extracts were analyzed by gas-liquid chromatography using thermionic detectors. Recoveries conducted at fortification levels ranging from 0.1 to 2 mg/kg were in most cases above 80%. The limit of sensitivity is less than 0.1 mg/kg.

Chromatography, Gas↗
PubMed1995

Studies on hepatic xenobiotic-metabolizing enzymes in rats treated with insecticide deltamethrin.

The effects of the synthetic dibromo-pyrethroid insecticide deltamethrin on some hepatic phase I and II enzyme activities were studied in rat liver. The animals were treated with daily doses of 5 and 10 mg/kg of both pure insecticide or its commercial formulation (Decis), administered i.p. in corn oil for 7 days. The following enzyme activities were studied: NADPH-cytochrome-P450 reductase, aryl-hydrocarbon hydroxylase, aminopyrine N-demethylase, glutamyl cysteine synthetase, glutathione S-transferase, glutathione peroxidase, peroxisomal acyl-CoA oxidase, catalase, and urate oxidase. Both deltamethrin and its commercial formulation were effective in modifying the activities of several of these hepatic xenobiotic-metabolizing enzymes. However, some differences in enzyme modifications were found between treatment with pure or commercial deltamethrin, the latter being more active. This effect could be ascribed to additives, solvents, and chemical intermediates present in the Decis formulation. These results suggest that exposure to this deltamethrin commercial formulation could be more dangerous than exposure to deltamethrin alone, both in terms of its hepatotoxicity and/or alterations in the hepatic biotransformation of other occupational/environmental xenobiotics.

Aminopyrine N-Demethylase↗
PubMed1993

Resistance to temephos, an organophosphorous insecticide, in Culex pipiens from Tunisia, North Africa.

Resistance to temephos, an organophosphorous insecticide (OP), was found to be low (2-fold) in 2 Culex pipiens populations collected in Sayada (mid-eastern Tunisia). This resistance was synergized by an esterase inhibitor (DEF). Two sets of over-produced esterases (A2-B2 and A4-B4), known to be involved in resistance, were identified in almost 50% of the examined insects. In addition, 3% of insects had an insensitive acetylcholinesterase. After selecting larvae of one of the samples (ES) with temephos for 6 generations, a 9-fold increase in resistance was observed, and all mosquitoes were found to carry esterases A2-B2 and an insensitive acetylcholinesterase. These results must be considered in future mosquito control programs, since 2 of the identified genes can lead to high resistance to several organophosphorous insecticides.

Animals↗
PubMed1995

Erythema multiforme major and disseminated intravascular coagulation in a dog following application of a d-limonene-based insecticidal dip.

Erythema multiforme major and disseminated intravascular coagulation developed in a dog 24 hours after exposure to a d-limonene-based insecticidal dip. Clinical signs included severe lethargy and weakness, ulceration of the oral mucosa, and erythematous serpiginous, annular, and arciform lesions on the head, trunk, and limbs. Clinicopathologic abnormalities included leukocytosis with neutrophilia, normocytic normochromic anemia, thrombocytopenia, prolongation of prothrombin and partial thromboplastin times, increased fibrin degradation products, hypoproteinemia, hyponatremia, hypochloremia, azotemia, high serum alanine aminotransferase and alkaline phosphatase activities, and high serum bilirubin concentration. Despite intensive supportive care, the dog developed severe intrathoracic and abdominal hemorrhage and died. Necropsy revealed severe diffuse epidermal necrosis and widespread hemorrhage within organs. Insecticidal dips containing d-limonene have the potential to induce various toxic effects, including, possibly, erythema multiforme major, and should be used cautiously.

Animals↗
PubMed1995

Phlebotomine sand fly (Diptera: Psychodidae) control using a residual pyrethroid insecticide.

Cyfluthrin was evaluated in the field as a residual insecticide to develop a new strategy for control of Old World phlebotomine sand fly vectors of leishmaniasis, which live and rest inside termite mounds and animal burrows. This insecticide was evaluated as a residual spray in Baringo District, Kenya, during 1993. Termite mounds and animal burrows were treated with a cyfluthrin/corn oil mixture (1.5% AI) using an 8-liter hand-pumped sprayer. Treatment of animal burrows and termite mounds with cyfluthrin provided control of sand flies inside these structures for 12 wk. Numbers of sand fly adults collected in light traps were reduced by up to 90% for 2 wk following treatment. This indicates that cyfluthrin provides short-term area control of adult sand flies when applied to termite mounds and animal burrows.

Animals↗