RESUMO
Highly toxic industrial chemicals that are widely accessible, and hazardous chemicals like phosgene oxime (CX) that can be easily synthesized, pose a serious threat as potential chemical weapons. In addition, their accidental release can lead to chemical emergencies and mass casualties. CX, an urticant, or nettle agent, grouped with vesicating agents, causes instant pain, injury and systemic effects, which can lead to mortality. With faster cutaneous penetration, corrosive properties, and more potent toxicity compared to other vesicating agents, CX causes instantaneous and severe tissue damage. CX, a potential chemical terrorism threat agent, could therefore be weaponized with other chemical warfare agents to enhance their harmful effects. CX is the least studied vesicant and its acute and long-term toxic effects as well as its mechanism of action are largely unknown. This has hampered the identification of therapeutic targets and the development of effective medical countermeasures. There are only protective measures, decontamination, and supportive treatments available for reducing the toxic effects from CX exposure. This review summarizes CX toxicity, its known mechanism of action, and our current studies exploring the role of mast cell activation and associated signaling pathways in CX cutaneous exposure under the National Institutes of Health Countermeasures Against Chemical Threats program. Potential treatment options and the development of effective targeted countermeasures against CX-induced morbidity and mortality is also discussed.
Assuntos
Oximas/toxicidade , Fosgênio/toxicidade , Substâncias para a Guerra Química/toxicidade , Irritantes , Pele/efeitos dos fármacosRESUMO
Este fungo foi isolado pela primeira vez de lagartas de L. obliqua de uma agregação em plátano (Platanus acerifolia (Aiton) Wild - Platanaceae), em Bento Gonçalves, RS, Brasil. Após isolamento, purificação e caracterização, realizou-se um teste de patogenicidade com lagartas sadias de L. obliqua para corroborar, sua infectividade pelo postulado de Koch. Constatou-se correspondência morfológica e molecular entre o inóculo e o reisolado, comprovando sua patogenicidade a L. obliqua.
It is recorded for the first time the occurrence of the entomopathogenic fungus Isaria javanica (Frieder. & Bally) Samson & Hywell-Jones (Fungi: Sordariomycetes) infecting Lonomia obliqua Walker (Lepidoptera: Saturniidae: Hemileucinae) caterpillars. This fungus was isolated from L. obliqua individuals collected from Platanus acerifolia (Aiton) Wild- Platanaceae in Rio Grande do Sul state, Brazil. After isolation, purification and characterization, fungal conidia were inoculated on healthy L. obliqua caterpillars and from dead caterpillars the fungal isolates were again obtained. New isolates and the original isolate did not differ when compared by morphological and molecular tests.
RESUMO
Lonomia obliqua Walker (Lepidoptera, Saturniidae) has urticant spines in larval stages. This species may cause death as a result of haemorrhages caused by a toxin released from the caterpillar's spines onto the skin of the victim when touched. In order to determine the morphological features of this species, studies were performed at the Laboratory of Entomology of the Pontifícia Universidade Católica do Rio Grande do Sul. The morphological aspects of eggs, larvae, pupae and adults are discussed as well as illustrated with pictures and drawings. The eggs are light green, 1.98 mm mean height, 1.45 mm large and 1.61 mm long. From the first to the sixth larval instar, the insect has spines on the body with different sizes and they are green-brownish with strong and dark heads. The mean sizes are 5.19 mm long at the first larval instar and 53.49 mm at the sixth instar. The head capsules are 1.01 mm and 4.83 mm wide at the first and sixth instars respectively. The mean lengths of the pupae are 28.73 mm for males and 30.23 mm for females. Adults have sexual dimorphism in which the male is smaller and yellow and the female is larger and grey-brownish. The mean adult wing span is 60.47 mm in males and 80.33 mm in females.
Lonomia obliqua Walker (Lepidoptera: Saturniidae) na fase de lagarta possui espinhos urticantes. Esta espécie pode causar a morte de pessoas pela hemorragia provocada pela toxina liberada pelos espinhos da lagarta na pele das vítimas no momento que entram em contato. Para determinar os aspectos morfológicos da espécie, foi realizado este trabalho no Laboratório de Entomologia da Pontifícia Universidade Católica do Rio Grande do Sul. São discutidos e ilustrados os aspectos morfológicos de todos os estádios do ciclo de vida (ovo, larva, pupa e adulto). Os ovos são verde-claros, com altura média de 1,98 mm, diâmetro menor de 1,45 mm e diâmetro maior de 1,61 mm. Na fase de lagarta, do primeiro ao sexto ínstar, há uma armadura de cerdas no corpo com a mesma estrutura, porém com desenvolvimento diferente; coloração castanho-claro-esverdeada com a cabeça mais escura e fortemente esclerotinizada na maioria dos ínstares. A lagarta de primeiro ínstar mede 5,19 mm e a do sexto ínstar 53,49 mm de comprimento, a largura da cápsula cefálica é de 1,01 mm para o primeiro ínstar e 4,83 mm para o sexto ínstar. O comprimento médio das pupas é de 28,73 mm para os machos e 30,23 mm para as fêmeas. Os adultos apresentam dimorfismo sexual acentuado, o macho é amarelado e menor que a fêmea que é mais robusta e de coloração castanho-acinzentada. A envergadura média dos adultos é de 60,47 mm nos machos e 80,33 mm nas fêmeas.