Voltage-clamp experiments on isolated giant axons of the cockroach Periplaneta americana L. show that chemically synthesized saxitoxin specifically and reversibly blocks the transient inward sodium current without affecting the steady-state outward potassium current. From the concentration depending of sodium current suppression it is concluded that individual sodium channels are blocked by sin...

Condylactis toxin induces a prolonged falling phase in action potentials recorded from giant axons of the cockroach Periplaneta americana L. A distinct plateau potential can be recorded in the presence of Condylactis toxin at concentrations of 0.5 mg/ml and above. In cockroach axons, voltage-clamp experiments show that Condylactis toxin acts primarily by slowing the sodium current turn-off with...

INTRODUCTION American cockroaches, Periplaneta americana, are the most important pests in hospitals and dwelling environments. They are mechanical vectors of some bacterial pathogens. GOAL The present investigation was carried out in Ghods hospital and 5 dwelling localities of Paveh city to evaluate bacterial infestations of American cockroaches in this region of Iran. METHODS The samples w...

Methods Children between 2 and 14 year old were submitted to a parasitological survey using the Hoffman, Pons e Janer (3 blades) method and the Kato-Katz (2 blades) method. The ISAAC questionnaire was applied to collect informations related to asthma. The Skin Prick Test was applied using extracts of Dermatophagoides pteronyssinus (DP), Blomia tropicalis (BT), Blatella germânica (BG), Periplane...

The cockroach Periplaneta americana is a notorious pest and threat to health worldwide, with a high reproductive ability. However, a limited amount of data is available on the developmental stage-specific transcriptomes of P. americana. To identify genes involved in developmental processes and to develop additional SSR markers in P. americana, we carried out de novo assembly of the P. americana...

Intracellular microelectrodes were used to study presynaptic inhibition at a cholinergic synapse between identified neurones: the lateral filiform hair sensory neurone (LFHSN) and giant interneurone 3 (GI 3) in the terminal ganglion of the first instar cockroach Periplaneta americana. The LFHSN-GI3 synapse was shown to fulfil physiological criteria for monosynaptic transmission: the latency of ...

The connective-tissue sheath surrounding the nervous system of Periplaneta americana consists of two layers, the neural lamella and the sheath cells beneath it. The neural lamella is composed of a collagen-type protein and neutral muco-polysaccharide. The sheath cells possess numerous lipochondria and mitochondria; the former consist of phospholipid and some cerebroside. The cytoplasm of the sh...

Periplaneta americana extracts (PAEs) play a crucial role in skin wound healing. However, their molecular effects and signaling pathways in regenerating tissues and cells are not clear. In this study, we refined the PAE from Periplaneta americana to investigate the mechanisms underlying skin wound healing. The human keratinocyte line HaCaT was selected and a mouse model of deep second-degree th...

Tritiated water (THO) loss from Periplaneta americana is used to measure cuticular permeability (Pd). In dry air, following various periods of predesiccation, the values of Pd lie around 0.5 x 10(-9) ms-1, with the lowest values below 0.3 x 10(-9) ms-1, close to the lowest permeabilities previously reported. There is no obvious relationship between permeability and initial mass of the insect. A...

BACKGROUND Cockroaches have been recognized as a powerful indoor allergen. Cockroach allergy can be a major factor in serious asthma and nasal allergy. Bioinformatics tools have been developed to identify potential allergens. The present study was conducted to identify potential allergens in Periplaneta americana (Linnaeus). METHODS The study focused on the identification of potential allerge...