Schistosomiasis is a water-borne parasitic illness caused by neoophoran trematodes of the genus Schistosoma. Using classical histological techniques and whole-mount preparations, the present work describes the embryonic development of Schistosoma mansoni eggs in the murine host and compares it with eggs maintained under in vitro conditions. Two pre-embryonic stages occur inside the female worm: the prezygotic stage is characterized by the release of mature oocytes from the female ovary until its fertilization. The zygotic stage encompasses the migration of the zygote through the ootype, where the eggshell is formed, to the uterus. Fully formed eggs are laid still undeveloped, without having suffered any cleavage. In the outside environment, eight embryonic stages can be defined: stage 1 refers to early cleavages and the beginning of yolk fusion. Stage 2 represents late cleavage, with the formation of a stereoblastula and the onset of outer envelope differentiation. Stage 3 is defined by the elongation of the embryonic primordium and the onset of inner envelope formation. At stage 4, the first organ primordia arise. During stages 5 to 7, tissue and organ differentiation occurs (neural mass, epidermis, terebratorium, musculature, and miracidial glands). Stage 7 is characterized by the nuclear condensation of neurons of the central neural mass. Stage 8 refers to the fully formed larva, presenting muscular contraction, cilia, and flame-cell beating. This staging system was compared to a previous classification and could underlie further studies on egg histoproteomics (morphological localizome). The differentiation of embryonic structures and their probable roles in granulomatogenesis are discussed herein.
This case report presents an analysis of the clinical, radiographic, and histological features of a peri-implant lesion around an implant placed immediately after extraction of a tooth with a periapical lesion. A 52-year-old man received an immediate implant (3.75 x 11.5 mm2) placed in the anterior region of the maxilla. Three years after implant placement, the patient presented with swelling in the anterior portion of the maxilla. Radiographic examination showed a well-circumscribed radiolucency around the implant. The implant and the lesion were removed and fixed in 10% buffered formalin and processed. Histological analysis showed 3 types of epithelium: respiratory, cuboidal, and non-keratinized stratified squamous. In the cyst wall peripheral nerves, arteries, veins, and chronic inflammation were present. The diagnosis was nasopalatine duct cyst. We concluded that the nasopalatine duct cyst can develop in association with dental implants. Clinically, the lesion is similar to the classical nasopalatine duct cyst. Histological analysis should be mandatory in all cases of peri-implant lesions and in all dental periapical lesions before immediate implant placement.
The growing number of patients suffering from chronic renal disease is a challenge for the development of innovative therapies. Benefits of cell therapy in acute renal diseases in animal models have been reported but seldom for chronic lesions. We present evidence for the improvement of renal morphology in a model of tubulointerstitial fibrosis. Wistar rats were submitted to unilateral ureteral obstruction (UUO), treated with bone-marrow mononuclear cells (UUO+BMMC) infused via the cava vein, and killed on day 14. Labeled BMMC were seen in renal tissue after 7 days in the group UUO+BMMC. UUO+BMMC also showed a reduction in ED1+ cells and tubular apoptotic cells together with enhanced tubular proliferation. Myofibroblasts were also reduced after BMMC which is consistent with a decrease in collagen deposition (picro Sirius staining) and RT-PCR data showing lower levels of procollagen-I mRNA. Simultaneously, nestin+ cells increased in the interstitium and decreased in the tubules. Double stained nestin+/α-SMA+ cells were present only in the interstitium, and their levels did not change after BMMC infusion. These data indicate a renoprotective effect of BMMC through increased tubular cell regeneration, inhibition of tubular cell apoptosis and partially blocking of the inflammatory and fibrotic events that occur after unilateral ureteral obstruction.
The processes of accumulation and mobilization of carbohydrate stores in eggs of Rhodnius prolixus were analyzed. During oogenesis, the total amounts of glycogen, glucose, and trehalose increased with an accumulation of proteins, especially when oocytes grew from 1.0 to 1.5 mm in length. At 2.0 mm length, when oocytes were ready for oviposition, nutrient reserves did not increase appreciably and trehalose content decreased. Mating did not affect the final content of carbohydrates or proteins in oocytes of mated and virgin females. A trehalase activity was detected in follicles containing vitellogenic oocytes, 1.0 and 1.5 mm length, in both mated and virgin females. This activity was extremely low in chorionated, 2.0-mm oocytes. After oviposition, glycogen content decreased in fertilized eggs, but not in unfertilized ones, and some was present in newly hatched nymphs. Glucose content remained constant in unfertilized eggs, but increased in fertilized ones, while total protein amount was constant in both groups after egg laying.
BackgroundHuman paracoccidioidomycosis (PCM) is an endemic fungal disease of pulmonary origin. Follow-up of pulmonary lesions by image studies in an experimental model of PCM has not been previously attempted. This study focuses on defining patterns, topography and intensity of lung lesions in experimentally infected PCM mice by means of a comparative analysis between High Resolution Computed Tomography (HRCT) and histopathologic parameters.MethodologyMale BALB/c mice were intranasally inoculated with 3×106 Paracoccidioides brasiliensis (Pb) conidia (n = 50) or PBS (n = 50). HRCT was done every four weeks to determine pulmonary lesions, quantify lung density, reconstruct and quantify lung air structure. Lungs were also analyzed by histopathology and histomorphometry.ResultsThree different patterns of lesions were evidenced by HRCT and histopathology, as follows: nodular-diffuse, confluent and pseudo-tumoral. The lesions were mainly located around the hilus and affected more frequently the left lung. At the 4th week post-challenge HRCT showed that 80% of the Pb-infected mice had peri-bronchial consolidations associated with a significant increase in upper lung density when compared with controls, (−263±25 vs. −422±10 HU, p<0.001). After the 8th and 12th weeks, consolidation had progressed involving also the middle regions. Histopathology revealed that consolidation as assessed by HRCT was equivalent histologically to a confluent granulomatous reaction, while nodules corresponded to individual compact granulomas. At the 16th week of infection, confluent granulomas formed pseudotumoral masses that obstructed large bronchi. Discrete focal fibrosis was visible gradually around granulomas, but this finding was only evident by histopathology.Conclusions/SignificanceThis study demonstrated that conventional HRCT is a useful tool for evaluation and quantification of pulmonary damage occurring in experimental mouse PCM. The experimental design used decreases the need to sacrifice a large number of animals, and serves to monitor treatment efficacy by means of a more rational approach to the study of human lung disease.
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