Spatial distribution of radiation dose to metastatic skeletal tumor from 153Sm-EDTM. A Monte Carlo simulation of a microCT based trabecular bone model.

Bone metastases are a very common problem in clinical oncology, affecting approximately 70% of patients with prostate or breast cancer. Radiopharmaceutical therapy has proved effective with minimal side effects for treatment of refractory painful skeletal metastases of the blastic or mixed type, but administered activities are generally based on limited series of clinical studies without a proven correlation between the activity and the delivered dose to metastatic lesions. In bone pain palliation therapy the red marrow is generally the dose-limiting organ and due to the complex microstructure of the skeleton it has been difficult to calculate accurately the dose deposited to this region. Thus, the estimation of dose to the skeletal system at the microscopic level has been limited by the lack of a realistic characterization of the trabecular bone architecture. The dose distribution to bone marrow of metastatic lesions for the bone seeking radiopharmaceutical 153Sm EDTMP has been evaluated using a Monte Carlo simulation. In this setting a new dosimetric model has been developed based on the micro-CT analysis of bone metastases to investigate the morphology, topology and texture of bone samples based on assessment of the micro-structural parameters classically evaluated with histomorphometry. The distribution of radiation dose and the mean absorbed dose per unit cumulated activity (S value) were computed for bone marrow space

Histological damage and inflammatory response elicited by Monobothrium wageneri (Cestoda) in the intestine of Tinca tinca (Cyprinidae)

Background: Among the European cyprinids, tench, Tinca tinca (L.), and the pathological effects their cestodes may effect, have received very little or no attention. Most literature relating to Monobothrium wageneri Nybelin, 1922, a common intestinal cestode of tench, for example, has focused on aspects of its morphology rather than on aspects of the host-parasite interaction. Results: Immunopathological and ultrastructural studies were conducted on the intestines of 28 tench, collected from Lake Piediluco, of which 16 specimens harboured tight clusters of numerous M. wageneri attached to the intestinal wall. The infection was associated with the degeneration of the mucosal layer and the formation of raised inflammatory swelling surrounding the worms. At the site of infection, the number of granulocytes in the intestine of T. tinca was significantly higher than the number determined 1 cm away from the site of infection or the number found in uninfected fish. Using transmission electron microscopy, mast cells and neutrophils were frequently observed in close proximity to, and inside, the intestinal capillaries; often these cells were in contact with the cestode tegument. At the host-parasite interface, no secretion from the parasite's tegument was observed. Intense degranulation of the mast cells was seen within the submucosa and lamina muscularis, most noticeably at sites close to the tegument of the scolex. In some instances, rodlet cells were encountered in the submucosa. In histological sections, hyperplasia of the mucous cells, notably those giving an alcian blue positive reaction, were evident in the intestinal tissues close to the swelling surrounding the worms. Enhanced mucus secretion was recorded in the intestines of infected tench. Conclusions: The pathological changes and the inflammatory cellular response induced by the caryophyllidean monozoic tapeworm M. wageneri within the intestinal tract of an Italian population of wild tench is reported for the first time

Proliferative cell nuclear antigen (PCNA) expression in the intestine of Salmo trutta trutta naturally infected with an acanthocephalan

Background: Changes in the production of proliferating cell nuclear antigen (PCNA), a 36 kd protein involved in protein synthesis, within intestinal epithelia can provide an early indication of deviations to normal functioning. Inhibition or stimulation of cell proliferation and PCNA can be determined through immunohistochemical staining of intestinal tissue. Changes in the expression of PCNA act as an early warning system of changes to the gut and this application has not been applied to the fields of aquatic parasitology and fish health. The current study set out to determine whether a population of wild brown trout, Salmo trutta trutta (L.) harbouring an infection of the acanthocephalan Dentitruncus truttae Sinzar, 1955 collected from Lake Piediluco in Central Italy also effected changes in the expression of PCNA. Methods: A total of 29 brown trout were investigated, 19 of which (i.e. 65.5%) were found to harbour acanthocephalans (5-320 worms fish-1). Histological sections of both uninfected and infected intestinal material were immunostained for PCNA. Results: The expression of PCNA was observed in the epithelial cells in the intestinal crypts and within the mast cells and fibroblasts in the submucosa layer which is consistent with its role in cell proliferation and DNA synthesis. The number of PCNA-positive cells in both the intestinal epithelium and the submucosa layer in regions close to the point of parasite attachment were significantly higher than the number observed in uninfected individuals and in infected individuals in zones at least 0.7 cm from the point of parasite attachment (ANOVA, p < 0.05). Conclusions: An infection of the acanthocephalan D. truttae within the intestinal tract of S. t. trutta effected a significant increase in the number of PCNA positive cells (mast cells and fibroblasts) at the site of parasite attachment when compared to the number of positive cells found in uninfected conspecifics and in tissue zones away from the point of parasite attachment

A modelagem matemática na perspectiva sociocrítica e a teoria da situação didática: identificando aproximações potencializadores da aprendizagem e do desenvolvimento do conhecimento reflexivo

Esse artigo, de cunho teórico, tem por objetivo refletir sobre as aproximações entre a Teoria da Situação Didática (TSD) e a Modelagem Matemática (MM) na perspectiva sociocrítica. Iniciamos embasando teoricamente a MM sob essa perspectiva e a TSD, para então, apresentarmos possíveis relações entre as etapas orientadoras de uma atividade de MM e as fases da TSD. Em seguida, discutimos as aproximações entre essas duas vertentes com foco no papel do aluno, do professor e do conhecimento em cada etapa. Construímos um esquema para evidenciar a relação dessas duas concepções bem como os papéis dos sujeitos envolvidos no processo. Entendemos que a relação entre MM e TSD pode potencializar a construção autônoma do conhecimento matemático, evidenciar a matemática do contexto social e envolver os alunos em discussões reflexivas

Innate immune defence mechanisms of tench, Tinca tinca (L.), naturally infected with the tapeworm Monobothrium wageneri

A histochemical and ultrastructural investigation of the cellular inflammatory response within the intestines of tench Tinca tinca L. naturally infected with the caryophyllidean cestode Monobothrium wageneri was conducted and the data obtained compared to those in uninfected counterparts. Cestode infections within the intestines were evident through the appearance of raised inflammatory swellings induced by the deep penetration of their scolices into the intestinal wall. Cestodes typically attached in tight clusters, inducing a massive hyperplastic granulocyte response of mast cells and neutrophils, which were significantly more numerous (P less than 0·01) in the intestines of infected (n = 14) than of uninfected (n = 9) tench. Neutrophils were more abundant than mast cells (P less than 0·01) in host tissues in close proximity to the parasite tegument. In transmission electron microscopy sections, mast cells and neutrophils were frequently observed in contact with or inside capillaries, and in close proximity to the cestode. Degranulation of both cell types was seen in the submucosa and lamina muscularis, notably in the immediate tissues surrounding the scolex of M. wageneri. No tegumental secretions were seen at the host-parasite interface. Occasional rodlet cells were encountered in the submucosa of infected fish

Mast cell responses to Ergasilus (Copepoda), a gill ectoparasite of sea bream

Immunocytochemical, light microscopy and ultrastructural studies were conducted on gill of sea bream, Sparus aurata L., naturally parasitized with the important parasitic copepod Ergasilus sp. to assess pathology and cellular responses. Thirty-seven S. aurata were examined from a fish farm; 26 (70%) were parasitized, with infection intensity ranging from 3 to 55 parasites per fish. Hosts were divided into two groups, lightly infected fish (15 parasites per fish). In histological sections, the copepod encircled gill lamellae with its second antennae, compressed the epithelium, provoked hyperplasia and hemorrhage, occluded arteries and often caused lamellar disruption. Fusion of the secondary lamellae due to epithelial hyperplasia was common in all infected fish; heavily infected fish showed more intense branchial inflammation. In both healthy and infected fish, mast cells (MCs) were free within the connective tissue inside and outside the blood vessels of the primary lamellae and made close contact with vascular endothelial cells, mucous cells and rodlet cells (RCs). MCs were irregular in shape with a cytoplasm filled by numerous electron-dense, membrane-bound granules. Immunostaining of primary and secondary gill filaments with an antibody against the antimicrobial peptide (AMP) piscidin 3 (anti-piscidin 3 antibody, anti-HAGR) revealed a subpopulation of MCs that were positive. These MCs were more abundant in gills of heavily infected fish than in either lightly infected or uninfected fish (ANOVA, P < 0.05). Our report documents the response of gill to ectoparasite infection and provides further evidence that mast cells and their AMPs may play a role in responding to branchial ectoparasite infections

A Modelagem Matemática na perspectiva sociocrítica e a Teoria da Situação Didática: identificando aproximações potencializadores da aprendizagem e do desenvolvimento do conhecimento reflexivo

Esse artigo, de cunho teórico, tem por objetivo refletir sobre as aproximações entre a Teoria da Situação Didática (TSD) e a Modelagem Matemática (MM) na perspectiva sociocrítica. Iniciamos embasando teoricamente a MM sob essa perspectiva e a TSD, para então, apresentarmos possíveis relações entre as etapas orientadoras de uma atividade de MM e as fases da TSD. Em seguida, discutimos as aproximações entre essas duas vertentes com foco no papel do aluno, do professor e do conhecimento em cada etapa. Construímos um esquema para evidenciar a relação dessas duas concepções bem como os papéis dos sujeitos envolvidos no processo. Entendemos que a relação entre MM e TSD pode potencializar a construção autônoma do conhecimento matemático, evidenciar a matemática do contexto social e envolver os alunos em discussões reflexivas

Histological damage and inflammatory response elicited by <it>Monobothrium wageneri </it>(Cestoda) in the intestine of <it>Tinca tinca </it>(Cyprinidae)

Abstract Background Among the European cyprinids, tench, Tinca tinca (L.), and the pathological effects their cestodes may effect, have received very little or no attention. Most literature relating to Monobothrium wageneri Nybelin, 1922, a common intestinal cestode of tench, for example, has focused on aspects of its morphology rather than on aspects of the host-parasite interaction. Results Immunopathological and ultrastructural studies were conducted on the intestines of 28 tench, collected from Lake Piediluco, of which 16 specimens harboured tight clusters of numerous M. wageneri attached to the intestinal wall. The infection was associated with the degeneration of the mucosal layer and the formation of raised inflammatory swelling surrounding the worms. At the site of infection, the number of granulocytes in the intestine of T. tinca was significantly higher than the number determined 1 cm away from the site of infection or the number found in uninfected fish. Using transmission electron microscopy, mast cells and neutrophils were frequently observed in close proximity to, and inside, the intestinal capillaries; often these cells were in contact with the cestode tegument. At the host-parasite interface, no secretion from the parasite's tegument was observed. Intense degranulation of the mast cells was seen within the submucosa and lamina muscularis, most noticeably at sites close to the tegument of the scolex. In some instances, rodlet cells were encountered in the submucosa. In histological sections, hyperplasia of the mucous cells, notably those giving an alcian blue positive reaction, were evident in the intestinal tissues close to the swelling surrounding the worms. Enhanced mucus secretion was recorded in the intestines of infected tench. Conclusions The pathological changes and the inflammatory cellular response induced by the caryophyllidean monozoic tapeworm M. wageneri within the intestinal tract of an Italian population of wild tench is reported for the first time.</p