RESUMEN
Early life events can change biochemical, endocrine and behavioral aspects throughout the life of an animal. Since there is a strong relationship between stress, neonatal handling and feeding behavior, the aim of this study was to investigate the effects of these three factors on behavioral parameters (anxiety and locomotion), oxidative stress in brain structures (prefrontal cortex and hippocampus) and on plasma glucose. Nests of Wistar rats were handled (10 min/day), or not (control groups), on days 1-10 after birth. Males from these groups were divided into 4 subgroups: (1) stressed by isolation in childhood (pre-puberty) and with access to a highly palatable diet (2) stressed by isolation and receiving standard lab chow (3) not isolated and receiving a highly palatable diet and (4) not isolated and receiving standard chow. The animals were kept under these conditions for 7 days. Rats receiving the highly palatable diet consumed more food, more calories, gained more weight and had a higher plasma glucose level, but had a lower caloric efficiency than the standard chow groups. Both handling and palatable diet were able to increase food consumption on the first day of isolation. Isolation stress had an anxiogenic effect in the plus maze, which was counteracted by handling. Palatable diet increased time spent in the central area of the open field apparatus and in the open arms of the elevated plus maze, showing an anxiolytic effect. The use of both these conditions, however, does not appear to bring additional protection against the effects of stress during this particular period of life, i.e., pre-puberty. In the prefrontal cortex, handling reduced thiol content and appears to imbalance the antioxidant enzymes system, which is counteracted by a palatable diet. Hippocampus seems to be more sensitive than the prefrontal cortex to early interventions, especially to the highly palatable diet, and both handling and diet appear to imbalance the antioxidant enzyme system. Thus, measurements of antioxidant enzymes activities indicate that handling may endanger some brain structures and that the palatable diet was able to prevent some handling effects on antioxidant enzymes, depending on the brain structure.
Asunto(s)
Ansiedad/psicología , Dieta , Estrés Oxidativo/fisiología , Glándulas Suprarrenales/fisiología , Animales , Glucemia/metabolismo , Peso Corporal/fisiología , Catalasa/metabolismo , Ingestión de Alimentos/fisiología , Conducta Alimentaria/fisiología , Femenino , Glutatión Peroxidasa/metabolismo , Manejo Psicológico , Hipocampo/metabolismo , Masculino , Actividad Motora/fisiología , Tamaño de los Órganos/fisiología , Corteza Prefrontal/metabolismo , Embarazo , Ratas , Ratas Wistar , Compuestos de Sulfhidrilo/metabolismo , Superóxido Dismutasa/metabolismoAsunto(s)
Animales , Masculino , Femenino , Gerbillinae , Oxyurida , Infecciones por Oxyurida , Enfermedades de los Roedores , Infecciones por OxyuridaRESUMEN
Helminth fauna of conventionally maintained hamsters from institutional animal houses that supply the research community with laboratory animals and from an openly kept control group, randomly purchased in a pet shop in the State of Rio de Janeiro, were evaluated and compared. Necropsied animals from institutional suppliers were infected with the oxyurid nematodes Syphacia criceti and S. mesocriceti and with the cestode Rodentolepis nana; those from the pet shop were infected with S. mesocriceti and R. nana. These are the first morphometric data that are based on Brazilian samples of these species parasitizing hamsters. Mesocricetus auratus is a newly recorded host for S. criceti, previously recovered from Oryzomys subflavus and Calomys callosus in Brazil. The potential of pet and laboratory hamsters in the spreading of helminth infections to humans is also considered.
Asunto(s)
Animales Domésticos/parasitología , Animales de Laboratorio/parasitología , Helmintiasis Animal/epidemiología , Parasitosis Intestinales/veterinaria , Mesocricetus/parasitología , Oxiuriasis/veterinaria , Animales , Brasil/epidemiología , Cricetinae , Femenino , Helmintos/citología , Helmintos/patogenicidad , Parasitosis Intestinales/epidemiología , Masculino , Oxyuroidea/anatomía & histologíaRESUMEN
Syphacia muris worm burdens were evaluated in the rat Rattus norvegicus of the strains Wistar (outbred), Low/M and AM/2/Torr (inbred), maintained conventionally in institutional animal houses in Brazil. Morphometrics and illustration data for S. muris recovered from Brazilian laboratory rats are provided for the first time since its proposition in 1935.
Asunto(s)
Animales de Laboratorio/parasitología , Oxyuroidea/citología , Ratas/parasitología , Animales , Femenino , Masculino , Oxyuroidea/fisiologíaRESUMEN
Nematodes studied herein and identified as Parabronema pecariae were collected in 1936 in the States of Rio de Janeiro and Pará and in 1940 in the State of Mato Grosso do Sul, Brazil. This species was proposed, with basis on female specimens that had been described earlier as Parabronema sp. Although the presence of males of P. pecariae was previously reported in Brazil, their description was not provided. The present paper deals with the first complete morphometric data on male specimens of P. pecariae recovered from peccaries (Pecari tajacu and Tayassu pecari).
Asunto(s)
Nematodos/anatomía & histología , Porcinos/parasitología , Animales , Brasil , Femenino , MasculinoRESUMEN
The present paper reports acuarioid nematodes recovered from avian hosts. A new species of the genus Schistorophus Railliet, 1916 is proposed based mainly on findings referring to ptilina, spicules and vagina. Ancyracanthopsis coronata (Molin, 1860) Chabaud & Petter, 1959 is referred again in Brazil since its proposition in 1860, from specimens recovered from a Brazilian bird. A revised key to the species of the genus Schistorophus is also presented.
Asunto(s)
Aves/parasitología , Nematodos/clasificación , Nematodos/aislamiento & purificación , Animales , BrasilRESUMEN
Worm burdens recovered from inbred mice strains, namely C57Bl/6, C57Bl/10, CBA, BALB/c, DBA/2 and C3H/He, conventionally maintained in two institutional animal houses in the State of Rio de Janeiro, RJ, Brazil, were analyzed and compared, regarding their prevalences and mean intensities. Three parasite species were observed: the nematodes Aspiculuris tetraptera, Syphacia obvelata and the cestode Vampirolepis nana. A modification of the anal swab technique is also proposed for the first time as an auxiliary tool for the detection of oxyurid eggs in mice.
Asunto(s)
Animales de Laboratorio/parasitología , Helmintiasis Animal/diagnóstico , Helmintiasis Animal/epidemiología , Helmintos , Animales , Brasil , Heces/parasitología , Masculino , Ratones , Ratones Endogámicos/parasitología , Recuento de Huevos de Parásitos , PrevalenciaRESUMEN
Synhimantus (Synhimantus) magnipapillatus n. sp., mainly considering the outstanding size of the cervical papillae and the delicate structure of the cephalic cordons, is not related to any other species of the genus, except for S. (S.) laticeps, concerning the similarities regarding the spicules, that justify their comparison.
Asunto(s)
Aves/parasitología , Nematodos/fisiología , Animales , Brasil , Femenino , Masculino , Nematodos/anatomía & histologíaAsunto(s)
Acantocéfalos/clasificación , Carnívoros/parasitología , Heces/parasitología , Fósiles , AnimalesRESUMEN
The spectrum of intestinal parasites present in the Swiss Webster, C57B1/6 and DBA/2 mice strains from different animal houses was identified and prevalences compared. Three parasites were observed during the course of this study, namely the cestode Vampirolepis nana (Siebold, 1852) Spasskii, 1954 (= Hymenolepis nana) and the nematodes Aspiculuris tetraptera (Nitzsch, 1821) Schultz, 1924 and Syphacia obvelata (Rudolphi, 1802) Seurat, 1916. The scope of this investigation has been widened to also include morphometric data on the parasites, to further simplify their identification, since the presence of helminths in laboratory animals is regarded as a restricting factor for the proper attainment of experimental protocols.
Asunto(s)
Hymenolepis/anatomía & histología , Parasitosis Intestinales/veterinaria , Ratones/parasitología , Nematodos/anatomía & histología , Animales , Animales de Laboratorio/parasitología , Femenino , Parasitosis Intestinales/parasitología , Masculino , Ratones Endogámicos C57BL/parasitología , Ratones Endogámicos DBA/parasitologíaRESUMEN
In previous studies, rabbits immunized with adult worm antigens released from fresh adult schistosomes incubated in saline media showed a significant level of protection against challenge parasites. Focusing on the rabbit-Schistosoma mansoni model, concomitant immunity was investigated. A peculiar form of response to cercarial infection was observed: rabbits subjected to percutaneous infection and similar reinfections at different times after primary infection killed schistosomula from the challenge infection as well as established parasites from the primary infection. In this study the challenge infection stimulus was replaced by active immunization with an adult worm-derived protective antigenic mixture. The results show that immunization of New Zealand rabbits with an adult worm antigenic extract is capable of inducing a response that results in a significant reduction of the mean worm burden of the primary infection earlier than did homologous infection, as compared to worm reduction due to a second infection.
Asunto(s)
Antígenos Helmínticos/inmunología , Inmunización , Schistosoma mansoni/inmunología , Esquistosomiasis mansoni/inmunología , Animales , Modelos Animales de Enfermedad , Masculino , Conejos , RecurrenciaRESUMEN
The migration of larval Schistosoma mansoni was tracked by means of autoradiographic analysis in naive rabbits percutaneously exposed to L-(75Se) selenomethionine-labeled cercariae on serial intervals of 1, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40 and 50 days post-infection. Autoradiographic foci were detected from the 1st day in the skin, up to the 15th day in the liver. Adult and mature worms were recovered either paired or not 60 days after infection, by perfusion of hepatic and mesenteric veins. Morphometric analysis under optical microscopy, showed that worms were within regular dimention limits as compared to adult worms harboured by other host species. These observations extend previous informations on the S. mansoni-rabbit association and clearly demonstrate the post-liver phase of S. mansoni life-cycle in this host.
Asunto(s)
Schistosoma mansoni/fisiología , Esquistosomiasis mansoni/parasitología , Animales , Autorradiografía , Modelos Animales de Enfermedad , Interacciones Huésped-Parásitos , Masculino , Ratones , ConejosRESUMEN
New Zealand rabbits were infected on day 1 and challenged on days 15, 30, and 60 with 1,000 Schistosoma mansoni cercariae/animal/infection. Challenged and control rabbits were perfused 60 days after each infection, corresponding to days 75, 90, and 120 after the first exposure. No decrease in number of adult schistosomes occurred in animals reinfected 15 days after primary infection, but, when the rabbits were challenged 30 and 60 days after the first infection, worm burden reduction of 61.4% and 92.6%, respectively, was observed as compared to infection controls. These data indicate that rabbits submitted to reinfection are able to kill the worms from their primary infection, besides being protected against challenge parasites.