Parasites
Thomas T. Yoshikawa, Shobita Rajagopalan in Antibiotic Therapy for Geriatric Patients, 2005
Common causes of fixed, painful subcutaneous swellings include myiasis, tungiasis, and furuncles. Myiasis is caused by invasion of the skin by the larvae of diptera (flies), including Cordylobia anthropophaga (the tumbu fly) in Africa and Dermatobia hominis (the botfly) in Latin America. Myiasis lesions resemble boils but have a central opening through which serosanguinous material oozes and through which the larvae may emerge (Fig. 1, panel D). Patients often report intermittent pain and a sensation of movement in the area of the lesion. Tungiasis (also known as jiggers), seen in travelers returning from Latin America, Africa, or India, develops after the female sand flea, Tunga penetrans, invades the skin, often around the toenails and soles (Fig. 1, panel E). Infection with Loa loa may become evident years after exposure as eyeworm or as migratory areas of angioedema (Calabar swellings),
Infections and infestations affecting the nail
Eckart Haneke in Histopathology of the NailOnychopathology, 2017
The diagnosis of an infestation requires at least parts of the parasite to be seen. The characteristic black spines of the exoskeleton of the botfly larva are diagnostic. Further, the patient's history is important.
Effect of Azadirachta indica A. Juss (Meliaceae) on the serotonin rhythm of Spodoptera frugiperda (Lepidoptera: Noctuidae)
Published in Chronobiology International, 2021
Erick Oyarzabal-Armendariz, Jesús Alquicira-Mireles, Beatriz Zúñiga-Ruíz, José Luis Arreola-Ramírez, Patricia Guevara-Fefer, César Oliver Lara-Figueroa, Elsa G. Escamilla-Chimal
Serotonin (5-hydroxytryptamine or 5HT) is a monoamine that was first characterized in 1948 by Rapport et al. (Rapport et al. 1948), it acts as a neurotransmitter, neuromodulator, and neurohormone, and plays an important role in the nervous system, metabolic processes, and circadian rhythms of diverse organisms (Cardinali et al. 1994). It has been proposed as a candidate for the integration of photic and non-photic signals (e.g., light and feeding) in the central nervous system of vertebrates (Kirsz and Zieba 2012) and comparable processes of insects (Vleugels et al. 2015). Although insects and mammals are very different in their physiology, they are evolutionary-preserved mechanisms, as reported by Banerjee and Rembold (Banerjee and Rembold 1992); these authors state that the most extensively studied insect neurosecretory system, the pars intercerebralis-corpus cardiacum complex, exhibits in functional terms many parallels with the hypothalamus-pituitary complex of mammals and other vertebrates. It is involved in the foundations of memory and associative learning in insects (Sitaraman et al. 2008), and it modulates the response of neuronal populations in the olfactory center of Bombix mori (Gatellier et al. 2004). It also has been proposed as a circadian modulator of the visual system of invertebrates (Nadakavukaren et al. 1986). A circadian rhythm of this monoamine has been characterized in the brain of the silk moth (B. mori) and the cricket (Acheta domesticus) (Gatellier et al. 2004; Muzynska-Pytel and Cymborowski 1978), and the relevance of the neural regulation of serotonin in locomotor activity has been reported for crickets (Gryllus bimaculatus) (Nishinokubi and Tomioka 2000). Furthermore, the importance of serotonin as a mediator in the circadian changes of the visual system has been observed in the botfly (Calliphora vicina) (Cymborowki 1998). This monoamine has been found also in other tissues, for example, in the stomatogastric system of the stick insect (Carausius morosus) (Luffy and Dorn 1991).
Related Knowledge Centers
- Gastrointestinal Tract
- Parasitism
- Dermatobia Hominis
- Myiasis
- Warble Fly
- Oestrinae
- Cuterebrinae
- Gasterophilinae
- Hypodermatinae
- Calliphoridae