ABSTRACT
The development of acquired resistance to Amblyomma cajennense ticks was evaluated. A total of 18 rabbits were uniformly distributed into three groups named GL, GN, and GA that were submitted to three consecutive infestations with, respectively, larvae, nymphs, and adults of A. cajennense. After the infestations, the parasitic and reproductive parameters of recovered instars were evaluated. A significant reduction of recovery rates of inoculated ticks was observed only after the third infestation of animals in groups GL and GN (P<0.01). The modal day for drop-off of engorged larvae and nymphs increased along the infestations. The recovered engorged nymphs presented a significant reduction of the mean body weight between the first and the third infestations (P<0.01). A significant reduction in the mean recovery rate of engorged females was only observed during the third infestation. However, significant reductions (P<0.05) in body weight, egg mass weight, and larva eclosions were observed for recovered engorged females after the second infestation onwards. The results suggest the occurrence of resistance of rabbits to A. cajennense infestations, being more evident against the adult stage.
Avaliou-se o desenvolvimento de resistência adquirida frente ao parasitismo por Amblyomma cajennense. Para tanto, 18 coelhos foram uniformemente distribuídos em três grupos denominados GL, GN e GA e submetidos a três infestações consecutivas por, respectivamente, larvas, ninfas ou adultos de A. cajennense. Após a infestação, estudaram-se os parâmetros parasitários e reprodutivos dos exemplares recuperados. Apenas a partir da terceira infestação dos animais dos grupos GL e GN, pôde-se observar uma queda significativa na taxa de recuperação dos ixodídeos inoculados (P<0,01). O dia modal de queda das larvas e ninfas recuperadas aumentou com o decorrer das infestações. As ninfas ingurgitadas recuperadas apresentaram uma redução significativa (P<0,01) no peso médio corporal entre a primeira e terceira infestação. Observou-se uma queda significativa na taxa média de recuperação das fêmeas ingurgitadas somente na terceira infestação (P<0,01). Todavia, a partir da segunda infestação observou-se nas teleóginas recuperadas, uma redução significativa no peso corporal, peso da postura e eclodibilidade das larvas (P<0,05). Os dados sugerem a ocorrência de resistência em coelhos à infestação por A. cajennense que foi mais evidente contra o estádio adulto.
Subject(s)
Animals , Ixodidae/parasitology , Lagomorpha/parasitology , Larva/physiology , Nymph/physiology , Tick Infestations/parasitologySubject(s)
Animals , Male , Moths/cytology , Spermatogenesis/physiology , Spermatozoa/cytology , Larva/cytology , Larva/physiology , Moths/physiology , Spermatozoa/physiologySubject(s)
Moths/cytology , Spermatogenesis/physiology , Spermatozoa/cytology , Animals , Larva/cytology , Larva/physiology , Male , Moths/physiology , Spermatozoa/physiologyABSTRACT
PURPOSE: To review our experience on the treatment of chronic pseudophakic endophthalmitis. METHODS: A retrospective and descriptive review of 6 consecutive cases: 4 after extracapsular cataract extraction and one after phacoemulsification with implant of posterior chamber intraocular lenses, and one aphakic patient after extracapsular cataract extraction. Treatment options included one or more of these techniques: intravitreal injection or anterior chamber injection or irrigation of the capsular bag with vancomycin (1.0 mg in 0.1 cc); pars plana vitrectomy with total or partial capsulectomy (with removal of the plaque) and the removal of the capsular bag and the intraocular lens through a limbal incision. RESULTS: 2 cases were managed with initial intravitreal vancomycin, associated in a third patient to a capsular bag irrigation. The two formers eventually required vitrectomy with posterior capsulotomy and removing of the white plaque; in a fourth patient, this technique was our initial step. Intraocular lens removal with capsular bag extraction was chosen as our first treatment measure on 2 patients and after vitrectomy failure in another case. Inflammation control was achieved in all our patients, although it took some time and some patients needed corticosteroids treatment during the meantime. CONCLUSIONS: Treatment indications of chronic postoperative endophthalmitis are not clearly established. In our experience, the best results are achieved with the techniques that remove completely the white plaque or the capsular bag and the intraocular lens.
