RESUMO

Despite the epidemiological importance of the Lymnaeidae family regarding transmission of Fasciola hepatica, knowledge about the diversity and distribution of these molluscs and the role of each species in the expansion of fasciolosis remains sparse. Classical morphological (n=10) identification was performed in lymneids from Lagoa Santa, a municipality in the state of Minas Gerais, Brazil, along with molecular and phylogenetic analysis (n=05) based on the partial nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I gene (COI mtDNA) and ribosomal internal transcribed spacer II (ITS-2 rDNA). The shell morphology made it possible to distinguish the lymneids of Lagoa Santa from Pseudosuccinea columella. Differences found in the penile complex and prostate shape allowed this species to be distinguished from Galba truncatula. However, the homogeneity of reproductive tract characteristics among Lymnaea (Galba) cubensis, L. viator and L. neotropica confirmed that these characteristics show low taxonomic reliability for identifying cryptic species. Genetic divergence analysis for the COI mtDNA gene and ITS-2 region of rDNA revealed greater similarity to Lymnaea (Galba) cubensis. Thus, correct species differentiation is important for monitoring the epidemiological risk of fasciolosis in the state of Minas Gerais, where cases of the disease have increased over recent years.

Assuntos

RESUMO

BACKGROUND: Angiostrongylus vasorum has different freshwater aquatic and terrestrial gastropod molluscs as an intermediate host, e.g. Arion spp. The mollusc Achatina fulica is a danger to public health, given the large diversity of nematodes utilizing it as an intermediate host, such as the parasites of the genus Angiostrongylus, of importance in human and veterinary medicine. Achatina fulica has been shown to have an excellent capacity for maintaining outbreaks and natural infections with A. cantonensis in Asia. Within the mollusc, the nematode parasites activate haemocytes and/or haemolymph factors and in some invertebrates, phenoloxidase (PO), that induces the release of toxic elements and eliminates the parasites. Despite the importance of A. fulica in the life-cycle of nematodes, little is known regarding the defence mechanisms involving PO in molluscs infected with nematodes. Here, the presence of PO and nitric oxide (NO) in the haemolymph and haemocytes of A. fulica infected with first-stage (L1) larvae of Angiostrongylus vasorum was evaluated, together with the presence of melanin in the cephalopod mollusc tissue. RESULTS: An increase in PO at one day post infection (dpi), in comparison with the control using the substrates L-tyrosine (F(4,90) = 6.73, P = 0.00006), L-DOPA (F(4,90) = 22.67, P = 0.02) and p-phenylenediamine (PPD) (F(4,90) = 27.58, P = 0.0019), was observed. PO increase coincided with the presence of melanin in the cephalopodal tissue. At 8 dpi, PO activity, compared to L-DOPA (F(4,90) = 22.67, P = 0.00002) and PPD (F(4,90) = 27.58, P = 0.079) decreased, while melanin increased. At 13 dpi, PO decreased with PPD (F(4,90) = 27.58, P = 0.000015) and also the amount of melanin observed in histology. At 30 dpi, PO increased along with the substrates L-DOPA and PPD, while melanin decreased. NO levels increased until 8 dpi, and decreased after 13 dpi. CONCLUSIONS: To our knowledge, this is the first study that illustrates PO activity in a helminth-infected A. fulica and provides the first observation of an L-tyrosine dependent PO activity in molluscs infected with A. vasorum. This work suggests that PO pathway may help to control A. vasorum infection in A. fulica.

Assuntos

RESUMO

Genetic susceptibility is associated with inflammation, neovascularization, and diabetes phenotypes. However, to what extent this susceptibility influences inflammatory angiogenesis in internal injuries in diabetes has not been fully investigated. Using the subcutaneous implantation of a synthetic matrix as an internal wound model in Swiss, C57BL/6 and Balb/c mice, we have studied inflammation, angiogenesis, and cytokine production in the fibrovascular tissue induced by implants in diabetic animals. The hyperglycemic levels (mg/dl) after the diabetogenic treatment were 455.0±15 in Swiss, 393.0±22 in C57BL/6, and 190.0±10 in Balb/c mice. Angiogenesis in Swiss implants from non-diabetic animals were higher than those in the implants from the other strains. However, the angiogenic inducers VEGF and nitric oxide (NO) were higher in implants from non-diabetic Swiss and Balb/c mice. Strain-related differences were also observed in the angiogenic parameters in implants from diabetic mice. Hb content and number of vessels decreased more than 40% in Swiss implants. In contrast, Hb content did not alter in implants from Balb/c diabetic mice and the number of vessels decreased. VEGF levels increased in implants from Swiss and C57BL/6 diabetic mice, but decreased in Balb/c implants. The levels of pro-inflammatory markers intra-implant also varied among the strains in both conditions. In the hyperglycemic environment, almost all inflammatory markers increased in implants from diabetic Swiss mice. These findings demonstrate the major contribution of genetic background in the pattern of inflammatory angiogenesis components of internal injury, in both normoglycemic and hyperglycemic animals.

Assuntos

RESUMO

The host response observed after the application of an appropriate stimulus, such as mechanical injury or injection of neoplastic or normal tissue implants, has allowed the cataloging of a number of molecules and cells involved in the vascularization of normal repair or neoplastic tissue. Implantation of sponge matrices has been adopted as a model for the accurate quantification of angiogenic and fibrogenic responses, as they may occur during wound healing, in vivo. Such implants are particularly useful because they offer scope for modulating the environment within which angiogenesis occurs. Sponge implantation model has been optimized and adapted to characterize essential components and their roles in blood vessels formation in a variety of physiological and pathological conditions. As a direct consequence of advances in genetic manipulation, mouse models (i.e., knockouts, SCID, nude) have provided resources to delineate the mechanisms regulating the healing associated with implants. Here we outline the usefulness of the sponge implant model of angiogenesis and detailed description of the methodology.

Assuntos

RESUMO

The 4T1 murine mammary carcinoma is an experimental model widely used in assessing and better understanding of tumor biology. It is a highly tumorigenic cell line and invasive, where metastases are observed in various organs. This study aims to describe morphological and immunophenotipical aspects of 4T1 mammary carcinoma in mice Balb/c with the aid of the immunohistochemistry. Tissues were fixed in formalin and processed using the routine paraffin inclusion technique. Histologic sections (4 m) were stained through Hematoxylin-Eosin techniques for morphologic assessments. For immunohistochemical study, we used a panel of 9 (nine) antibodies: hormone receptors, receptors for cell proliferation, cytokeratins, vimentin, growth factor receptor and markers of blood vessels. Morphologically, the 4T1 murine mammary carcinoma shows malignant epithelial proliferation in solid arrangement, with pleomorphic cells and high mitotic index. In immunohistochemical analysis was determined a positivity for hormone receptors, cytokeratin AE1/AE3, receptors of cell proliferation and markers of blood vessels. There was a negative for vimentin, cytokeratin 5/6, cytokeratin 34E12 and growth factor receptor.The results show that the characteristics observed in this model are similar to some types of breast cancers found in women like poorly differentiated invasive ductal carcinoma. Thus, the immunophenotypic characterizationof mammary carcinoma 4T1 allows a better understanding of the model to the study of new anticancer therapies.

Assuntos

RESUMO

The 4T1 murine mammary carcinoma is an experimental model widely used in assessing and better understanding of tumor biology. It is a highly tumorigenic cell line and invasive, where metastases are observed in various organs. This study aims to describe morphological and immunophenotipical aspects of 4T1 mammary carcinoma in mice Balb/c with the aid of the immunohistochemistry. Tissues were fixed in formalin and processed using the routine paraffin inclusion technique. Histologic sections (4 m) were stained through Hematoxylin-Eosin techniques for morphologic assessments. For immunohistochemical study, we used a panel of 9 (nine) antibodies: hormone receptors, receptors for cell proliferation, cytokeratins, vimentin, growth factor receptor and markers of blood vessels. Morphologically, the 4T1 murine mammary carcinoma shows malignant epithelial proliferation in solid arrangement, with pleomorphic cells and high mitotic index. In immunohistochemical analysis was determined a positivity for hormone receptors, cytokeratin AE1/AE3, receptors of cell proliferation and markers of blood vessels. There was a negative for vimentin, cytokeratin 5/6, cytokeratin 34E12 and growth factor receptor.The results show that the characteristics observed in this model are similar to some types of breast cancers found in women like poorly differentiated invasive ductal carcinoma. Thus, the immunophenotypic characterizationof mammary carcinoma 4T1 allows a better understanding of the model to the study of new anticancer therapies.(AU)

Assuntos

RESUMO

Carboplatin is commonly used to treat a variety of tumors. We investigated the effects of carboplatin (100mg/kg) in the development and metastatic dissemination of the 4T1 mice mammary carcinoma. Carboplatin was able to reduce tumor volume and the number of lung metastases in 50% compared to the control animals. Mitotic and apoptotic indices were also decreased by the treatment. Assessment of the vascularization of the tumors revealed a significant decrease in blood vessel formation by carboplatin. A decrease in nuclear positivity of CDC47 and cyclin D1 was observed in the group treated with carboplatin when compared to the control group. Positivity for p53 was observed in the control group (2/28; 5%) and the treated group (5/71; 4%). Carboplatin has been demonstrated to be an efficient regulator of 4T1MMT growth and dissemination. The action of this chemotherapeutic agent seems to be related to the induction of apoptosis and inhibition of angiogenesis and cell proliferation.

Assuntos

RESUMO

Inflammation and angiogenesis, key components of fibrovascular tissue growth, exhibit considerable variability among species and strains. We investigated whether the response of inbred and outbred mice strains to dipyridamole (DP) on these processes would present similar variability. The effects of the drug on blood vessel formation, inflammatory cell recruitment, collagen deposition and cytokine production were determined on the fibroproliferative tissue induced by sponge implants in Swiss and Balb/c mice. Angiogenesis as assessed by hemoglobin (Hb) and vascular endothelial growth factor (VEGF) concentrations differed between the strains. Swiss implants had the highest Hb content but the lowest VEGF concentrations. Systemic DP treatment exerted an antiangiogenic effect on Balb/c implants but an proangiogenic effect on Swiss implants. The inflammatory enzyme activities myeloperoxidase (six-fold higher in Balb/c implants) and N-acetyl-ß-D-glucosaminidase were reduced by the treatment in Balb/c implants only. Nitrite concentrations were also higher in Balb/c implants by 40% after DP treatment. Tumor necrosis factor-alpha levels were similar in the implants of both strains and were not reduced by DP. Transforming growth factor ß-1 levels and collagen deposition also varied between the strains. The inbred strain had similar levels of the cytokine but implants of Swiss mice presented more collagen. DP treatment reduced collagen deposition in Balb/c implants only. Our data showing the influence of the genetic background on marked heterogeneity of inflammatory angiogenesis components and differential sensitivity to DP may provide some answers to clinical evidence for resistance to angiogenic therapy.

Assuntos

RESUMO

INTRODUCTION AND OBJECTIVE: Kint3-4 protein, originated from a genetic recombination of K1-3 and K1-4 human plasminogen segments, is recognized for its antiangiogenic and anti-inflammatory potential. This study aimed to evaluate the effect of Kint3-4 protein on tumor development in Swiss mice previously inoculated with Ehrlich tumor cells. METHODS: The protein fragment was obtained from Pichia pastoris cloning and transformation. After tumor cell inoculation three different protocols were used to assess tumor growth: beginning (0-6 days), peak (0-12 days) and after peak (0-18 days). We analyzed tumor growth, histomorphological characteristics and immunohistochemistry by use of CDC47 (cellular proliferation marker) and CD31 (blood vessel marker). RESULTS: Animals treated with Kint3-4 protein (150 µg/kg/48 h) showed lower tumor growth in all protocols. Based on histological assessment, inflammation and tumor areas were also reduced. Moreover, both the lowest rate of tumor cell proliferation and low microvessel density were observed in animals treated with Kint3-4 protein compared with the untreated control group. CONCLUSION: The effect of Kint3-4 recombinant protein on tumor angiogenesis and control of malignant cell proliferation enhances the prospects of its use in clinical and antiangiogenic treatment.

INTRODUÇÃO E OBJETIVO: A proteína Kint3-4 originou-se a partir de uma recombinação genética dos segmentos K1-3 e K1--4 do plasminogênio humano e é reconhecida por seu potencial anti-inflamatório e antiangiogênico. Este estudo teve como objetivo avaliar o efeito da proteína Kint3-4 no desenvolvimento de tumores em camundongos inoculados com células do tumor de Ehrlich. MÉTODOS: O fragmento de proteína foi obtido por uma técnica de clonagem e transformação de Pichia pastoris. Três diferentes protocolos foram avaliados após a inoculação das células tumorais: no início (0-6 dias), no pico (0-12 dias) e após o pico (0-18 dias) de crescimento do tumor. Foram analisados o crescimento do tumor e as características histomorfológica e imuno-histoquímica com CDC47 (marcador de proliferação celular) e CD31 (marcador de vasos sanguíneos). RESULTADOS: Os animais tratados com a proteína Kint3-4 (150 µg/kg/48 h) nos três diferentes protocolos apresentaram menor crescimento do tumor. Áreas de inflamação e tumor também foram reduzidas, avaliadas por exame histológico. Além disso, a menor taxa de proliferação das células tumorais e a baixa densidade de microvasos foram observadas nos animais tratados com proteína Kint3-4 em comparação com o grupocontrole. CONCLUSÃO: A participação da proteína recombinante Kint3-4 na angiogênese tumoral e no controle da proliferação de células malignas abre perspectivas para seu uso no tratamento clínico como antiangiogênico.

Assuntos

RESUMO

Angiogenesis and inflammation are persistent features of several pathological conditions. Propolis, a sticky material that honeybees collect from living plants, has been reported to have multiple biological effects including anti-inflammatory and anti-neoplasic activities. Here, we investigated the effects of water extract of green propolis (WEP) on angiogenesis, inflammatory cell accumulation and endogenous production of cytokines in sponge implants of mice over a 14-day period. Blood vessel formation as assessed by hemoglobin content and by morphometric analysis of the implants was reduced by WEP (500 mg kg(-1) orally) compared to the untreated group. The levels of vascular endothelial growth factor (VEGF) increased progressively in the treated group but decreased after Day 10 in the control group. Accumulation of neutrophils and macrophages was determined by measuring myeloperoxidase (MPO) and N-acetyl-ß-(D)-glucosaminidase (NAG) activities, respectively. Neutrophil accumulation was unaffected by propolis, but NAG activity was reduced by the treatment at Day 14. The levels TGF-ß1 intra-implant increased progressively in both groups but were higher (40%) at Day 14 in the control implants. The pro-inflammatory levels of TNF-α peaked at Day 7 in the control implants, and at Day 14 in the propolis-treated group. Our results indicate that the anti-inflammatory/anti-angiogenic effects of propolis are associated with cytokine modulation.