Deltamethrin contact exposure mediated toxicity and histopathological aberrations in tissue systems of cockroach species Periplaneta americana and Blatella germanica

Cockroach species Periplaneta americana and Blatella germanica potentially survive in locations close to human activity. Besides spoiling food material, cockroaches also transfer pathogens of different diseases among human. Since the insecticides have been used extensively to control cockroaches, information on their insecticide susceptibility and toxicity at cellular level may be crucial. In the study, deltamethrin toxicity as well as the deltamethrin-mediated cytomorphological changes in brain, ovary and midgut of the two important cockroach species has been assessed. Different concentrations [0.00025% (0.0025mg/ml), 0.0025% (0.025mg/ml), 0.025 (0.25mg/ml), 0.25% (2.5mg/ml), 0.5% (5mg/ml), 1% (10mg/ml)] of deltamethrin in acetone were used to expose test species in WHO bottle assay. Knockdown was recorded after 5 min interval while delayed mortality was observed after 24 hr. Brain, ovary and gut were dissected post 1 hr exposure and 24 hr holding (for 0.25%, 0.5% and 1% concentration), and tissues were processed for microscopic analysis. Deltamethrin exposed cockroaches and dissected tissues were used to estimate deltamethrin using HPLC. At 0.00025% (lowest concentration), the percentage knock-down observed was 66.7% for P. americana and 80% B. germanica respectively (R2= 0.78; p=0.0001) in 1 hr. KDT50 value was found to be 8.7 min (95% CI: 7.3-10.2), while KDT99 was 20.7 min (95% CI: 16.0-35.7) in P. americana at 1% concentration. Whereas, the KDT50 and KDT99 values for B. germanica were 7.4 min (95% CI: 5.4-9.1) and 27.4 min (95% CI: 18.2-80.0) at similar concentration. LD50 and LD95 values (for 60 min standard exposure) were 0.0006 % (95% CI: 0.00-0.001) and 0.034% (95% CI: 0.013-0.49) respectively for P. americana, while these values were 0.0005 (95% CI: 0.00-0.001) and 0.04 (95% CI: 0.01-0.23) for B. germanica. Exposure to 1% deltamethrin induced considerable toxic effect in the epithelial cells in the midgut. HPLC estimated 0.21±0.05 mg (95% CI - 0.18-0.25; CoV 23.9%) deltamethrin in P. americana post 1% exposure. Even short term exposure of low concentration of synthetic pyrethroid deltamethrin displayed immediate knockdown and delayed mortality in both the test species. Considerable histological damage was observed in both the insects at 1% exposure. In India, resistance to deltamethrin may have been reported among different insects due its extensive use, however the formulations such as insecticide paints, attractant baits etc. developed using deltamethrin as active ingredient could be useful in cockroach control operations.

Prevalencia de sensibilización a cucaracha (Periplaneta americana y Blatella germánica). Experiencia del Servicio de alergia e inmunología clínica del Hospital General de México.

Antecedentes: Las pruebas cutáneas por técnica de punción son herramientas importantes para el diagnóstico de la alergia respiratoria. Se han identificado los antígenos de las cucarachas como responsables del desarrollo de rinitis, asma y otras enfermedades alérgicas. Objetivo: Demostrar la participación del antígeno de cucaracha en enfermedades alérgicas. Métodos: Se llevó a cabo un estudio retrolectivo y transversal, para el cual se revisaron historias clínicas y los antecedentes de atopia; se recolectaron los resultados de biometría hemática, citología nasal, IgE total y estudio coproparasitoscópico seriado. Previo consentimiento informado se aplicaron pruebas cutáneas en pacientes de tres a 74 años. Resultados: Se estudiaron 1837 pacientes, la prevalencia de reactividad cutánea al antígeno de cucaracha fue de 17.90 %; 56 % de los pacientes tenía diagnóstico de rinitis alérgica y solo 6 %, de asma y rinitis. Conclusión: Se debe considerar la aplicación del antígeno de cucaracha en las pruebas cutáneas en la práctica del alergólogo.

FORMULASI FLY SPRAY DARI EKSTRAK PIRETRUM DAN EFFEKTIVITASNYA TERHADAP SERANGGA RUMAH TANGGA

<p>Telah dilakukan pembuatan formula fly spray dengan bahan aktif utama ekstrak piretrum dan uji efTektivitasnya dilakukan terhadap serangga rumah tangga. Penelitian dimulai dari April sampai Oktober 2001 di Laboratorium Fisiologi Hasil dan Keteknikan, Balinro dan Laboratorium Entomologi, Fakultas Kedokteran Hewan, IPB Komponen formula terdiri dari ekstrak piretrum, minyak serai wangi, minyak wijen, naftalen, pine oil, pclarut pertasol CB dan LAWS. Perlakuan formulasi yaitu dibual variasi konsentrasi ekstrak piretrum ( 0.041% dan 0.052% ), penambahan/tanpa pine oil (0%, 0.1%) dan natalen (0%, 1.0%) serta jenis pclarut (LAWS dan pertasol CB). Uji effektivitas dilakukan terhadap serangga rumah tangga yaitu lalat, nyamuk, semut dan kecoa. Hasil menunjukkan bahwa dua formula yaitu Fi dan F, adalah formula paling effektif terhadap lalat Musca domeslica dan sebagai formula terpilih adalah Fj. Formula ini effektif terhadap nyamuk Culex qumquefasciatus dengan mematikan 92% pada menit ke dua sangat efektif terhadap semut t'onera sp. dengan angka kematian 100% pada menit ke dua, dan kurang effektif terhadap kecoa Blatella germanica menyebabkan kematian 90% pada menil ke 30. Komposisi formula F&gt; terdii dari ekstrak piretrum dengan kadar piretrin 0.041%, minyak serai wangi 0.1%, minyak wijen 3%, natalen 1% dan pelarut LAWS. Pelarut terbaik untuk formula ini adalah LAWS.</p><p>Kata kunci: Fly spray, Piretrum, formulasi, uji effektivitas, serangga rumah tangga</p><p> </p><p><strong>ABSTRACT </strong></p><p><strong>Fly spray formulation of pyrethrum extract and its effectiveness on houseflies</strong></p><p>The production of ly spray formula with active ingredient pyrethrum extract and its efficacy on houselics were conducted from Apil to October 2001 at (he Research Institute for Spice and Medicinal Crops, Bogor and at Entomology laboratory of FKH - IPB. The formula was made from pyrethrum extract, citronella oil, sesame oil, natalein, pine oil and solvent, i.e pertasol CB and LAWS. The parameters observed were the variation concentration of pyrethrum extract (0.041% and 0.051%), added with pine oil (0%, 0.1%), natalein (0%, 1.0%) and solvents (LAWS and pertasol CB). The eficacy lest was conducted on houselies which included housely, mosquito, ant and cockroach. The result showed that F&gt; and Fi were ihe most effective to M. domeslica and Fi is the selected formula. Fi was effective to Cx. qumquefasciatus mosquito which killed 92% of the mosquito in two minutes, and very effective to Ponera sp ants which killed 100% in iwo minutes, and less effective to B. germanica cockroach which killed 90% in half hour. The Fj formula was made from pyrethrum extract with 0.041% piretrin, 0.1% citronella oil, 3% sesame oil, 1% natalein and LAWS solvent LAWS was the best solvent for the formula.</p><p>Key words : Fly spray, pyrethrum, formulation, efficacy test, houselies</p>

Weak radiofrequency fields affect the insect circadian clock

It is known that the circadian clock in Drosophila can be sensitive to static magnetic fields (MFs). Man-made radiofrequency (RF) electromagnetic fields have been shown to have effects on animal orientation responses at remarkably weak intensities in the nanotesla range. Here, we tested if weak broadband RF fields also affect the circadian rhythm of the German cockroach ( Blatella germanica ). We observed that static MFs slow down the cockroach clock rhythm under dim UV light, consistent with results on the Drosophila circadian clock. Remarkably, 300 times weaker RF fields likewise slowed down the cockroach clock in a near-zero static magnetic field. This demonstrates that the internal clock of organisms can be sensitive to weak RF fields, consequently opening the possibility of an influence of man-made RF fields on many clock-dependent events in living systems.

SENSIBILIZAÇÃO DA BLOMIA TROPICALIS EM PACIENTES ASMÁSTICOS EM SÃO LUÍS E REGIÕES METROPOLITANA

As doenças alérgicas podem causar comprometimento da qualidade de vida das crianças, no qual está exposto a uma série de alérgenos, que podem gerar uma resposta do sistema imunológico como reações de hipersensibilidade. O objetivo da pesquisa foi avaliar o perfil sócio-econômico e ambiental de crianças e adolescentes sensibilizados a Blomia tropicalis (Blo t) em São Luís e região metropolitana. Aprovada pelo comitê de ética e pesquisa, com o parecer de numero: 58737916.30000.5084. Foi realizado um estudo epidemiológico por meio de análise de prontuários em pacientes do Hospital da Criança de São Luís-MA, onde foram submetidos ao teste cutâneo para o alérgeno Blo t e aplicado o questionário ISSAC e complementar. Teste estatístico utilizado foi o Qi-quadrado- Fisher. A população estudada foi constituída por 87 crianças e adolescentes, entre idade de 1 a 17 anos. Na caracterização clínica destes pacientes foi observado uma associação entre a sensibilização o Blo t e a sensibilização ao Dermatophagoides pteronissynus, Dermatophagoides farinae, Periplaneta americana, Blatella germânica e ao cachorro. Observou-se também uma associação com baixa renda familiar, asma e eczema atópico. Quanto a caracterização ambiental observou-se uma correlação entre manchas na parede (mofo) e forro no quarto. Concluímos que a sensibilização o Blo t é um fator de risco para desenvolvimento de asma e eczema e esta relacionado com vários alérgenos, a baixa renda familiar e que o controle ambiental para blo t é essencial para diminuir a prevalência da asma e do eczema e para melhorar a qualidade vida.PALAVRAS-CHAVE: asma; alérgeno; hipersensibilidade