Changes in the conformation of apoliprotein B-100 in the early stages of copper-mediated low dens... more Changes in the conformation of apoliprotein B-100 in the early stages of copper-mediated low density lipoprotein oxidation have been monitored by infrared spectroscopy. During the lag phase no variation in structure is observed, indicating that copper binding to the protein does not significantly affect its structure. In the propagation phase, while hydroperoxides are formed but the protein is not modified, no changes in secondary structure are observed, but the thermal profile of the band corresponding to alpha-helix is displaced in frequency, indicating changes in tertiary structure associated with this conformation but not with beta-sheet components. When aldehyde formation starts, a decrease of approximately 3% in the area of bands corresponding to alpha-helix and beta-sheet is produced, concomitantly with an increase in beta-turns and unordered structure. The two bands corresponding to beta-turns vary as well under these conditions, indicating changes in these structures. Also ...
Following selection of appropriate culture conditions, various experiments were conducted to eval... more Following selection of appropriate culture conditions, various experiments were conducted to evaluate the suitability of the micronucleus assay in cytokinesis-blocked lymphocytes for biological dosimetry purposes. A dose-effect relationship was determined, based on the frequency of micronuclei induced by various doses of 60Co gamma-rays. The data were best fitted to a linear-quadratic model. To validate the system, an attempt was made to estimate unknown dose levels from the yield of micronuclei, by inverting the derived dose-response function. It was concluded that the assay provides a valid approach for dose assessment. The size of radiation-induced micronuclei was measured in relation to the dose. A significant difference in the proportion of large micronuclei between high and low doses was observed. The chromosomal composition of micronuclei, detected by immunofluorescent staining of kinetochores, showed that only a small proportion of micronuclei contains kinetochore. The possi...
Introduction: worldwide, infection, usually caused by Group B Streptococcus, is the leading cause... more Introduction: worldwide, infection, usually caused by Group B Streptococcus, is the leading cause of morbidity/mortality at the neonatal intensive care units. Objectives: to describe the prevalence of colonization by this microorganism in the lower genital tract of pregnant women between weeks 35.0 and 37.6 at Hospital de San JosØ. Materials and Methods: this is a cross sectional descriptive study. Vagina
Integrins regulate both adhesion and signaling processes involved in proliferation and survival. ... more Integrins regulate both adhesion and signaling processes involved in proliferation and survival. αvβ3 and αvβ5 integrins have been shown to mediate cell adhesion and migration. Here we used human ovarian cancer cell lines (IGROV1, SKOV-3) that express αvβ3 and αvβ5 to study their role in cell proliferation and the signaling pathways involved. We found that αv integrins regulate cell proliferation
Integrins are essential protagonists of the complex multi-step process of angiogenesis that has n... more Integrins are essential protagonists of the complex multi-step process of angiogenesis that has now become a major target for the development of anticancer therapies. We recently reported and characterized that MVL-PLA2, a novel phospholipase A2 from Macrovipera lebetina venom, exhibited anti-integrin activity. In this study, we show that MVL-PLA2 also displays potent anti-angiogenic properties. This phospholipase A2 inhibited adhesion and migration of human microvascular-endothelial cells (HMEC-1) in a dose-dependent manner without being cytotoxic. Using Matrigel and chick chorioallantoic membrane assays, we demonstrated that MVL-PLA2, as well as its catalytically inactivated form, significantly inhibited angiogenesis both in vitro and in vivo. We have also found that the actin cytoskeleton and the distribution of alphav beta3 integrin, a critical regulator of angiogenesis and a major component of focal adhesions, were disturbed after MVL-PLA2 treatment. In order to further investi...
Although rhabdomyosarcoma is the most frequent soft tissue tumor in children, there are extremely... more Although rhabdomyosarcoma is the most frequent soft tissue tumor in children, there are extremely few reports of this tumor arising from the urachus. The authors describe another case in a 6-year-old female associated with constipation and a painless suprapubic mass. The specimen had the pathological criteria used to define urachal sarcoma (cytological, histological, and immunohistochemical findings) and urachal remnants were not observed. After complete resection of the primary tumor the patient was treated with chemotherapy (ifosfamide, vincristine, and dactinomycin) and remains alive at 4 years' follow-up with no signs of recurrence. Nowadays the management of children with urachal rhabdomyosarcoma usually includes surgery and chemotherapy. Multimodal therapy and surgery are constantly evolving and have significantly improved overall survival of these patients especially in R0 resected patients.
Abstract. Our main objective was to use comparative floristic and structural criteria in order to... more Abstract. Our main objective was to use comparative floristic and structural criteria in order to understand the differences in assemblages brought about by the meeting of arid and dry-tropical environments. We sampled 33 vegetation plots and recorded all perennial species. The ...
Changes in the conformation of apoliprotein B-100 in the early stages of copper-mediated low dens... more Changes in the conformation of apoliprotein B-100 in the early stages of copper-mediated low density lipoprotein oxidation have been monitored by infrared spectroscopy. During the lag phase no variation in structure is observed, indicating that copper binding to the protein does not significantly affect its structure. In the propagation phase, while hydroperoxides are formed but the protein is not modified, no changes in secondary structure are observed, but the thermal profile of the band corresponding to alpha-helix is displaced in frequency, indicating changes in tertiary structure associated with this conformation but not with beta-sheet components. When aldehyde formation starts, a decrease of approximately 3% in the area of bands corresponding to alpha-helix and beta-sheet is produced, concomitantly with an increase in beta-turns and unordered structure. The two bands corresponding to beta-turns vary as well under these conditions, indicating changes in these structures. Also ...
Following selection of appropriate culture conditions, various experiments were conducted to eval... more Following selection of appropriate culture conditions, various experiments were conducted to evaluate the suitability of the micronucleus assay in cytokinesis-blocked lymphocytes for biological dosimetry purposes. A dose-effect relationship was determined, based on the frequency of micronuclei induced by various doses of 60Co gamma-rays. The data were best fitted to a linear-quadratic model. To validate the system, an attempt was made to estimate unknown dose levels from the yield of micronuclei, by inverting the derived dose-response function. It was concluded that the assay provides a valid approach for dose assessment. The size of radiation-induced micronuclei was measured in relation to the dose. A significant difference in the proportion of large micronuclei between high and low doses was observed. The chromosomal composition of micronuclei, detected by immunofluorescent staining of kinetochores, showed that only a small proportion of micronuclei contains kinetochore. The possi...
Introduction: worldwide, infection, usually caused by Group B Streptococcus, is the leading cause... more Introduction: worldwide, infection, usually caused by Group B Streptococcus, is the leading cause of morbidity/mortality at the neonatal intensive care units. Objectives: to describe the prevalence of colonization by this microorganism in the lower genital tract of pregnant women between weeks 35.0 and 37.6 at Hospital de San JosØ. Materials and Methods: this is a cross sectional descriptive study. Vagina
Integrins regulate both adhesion and signaling processes involved in proliferation and survival. ... more Integrins regulate both adhesion and signaling processes involved in proliferation and survival. αvβ3 and αvβ5 integrins have been shown to mediate cell adhesion and migration. Here we used human ovarian cancer cell lines (IGROV1, SKOV-3) that express αvβ3 and αvβ5 to study their role in cell proliferation and the signaling pathways involved. We found that αv integrins regulate cell proliferation
Integrins are essential protagonists of the complex multi-step process of angiogenesis that has n... more Integrins are essential protagonists of the complex multi-step process of angiogenesis that has now become a major target for the development of anticancer therapies. We recently reported and characterized that MVL-PLA2, a novel phospholipase A2 from Macrovipera lebetina venom, exhibited anti-integrin activity. In this study, we show that MVL-PLA2 also displays potent anti-angiogenic properties. This phospholipase A2 inhibited adhesion and migration of human microvascular-endothelial cells (HMEC-1) in a dose-dependent manner without being cytotoxic. Using Matrigel and chick chorioallantoic membrane assays, we demonstrated that MVL-PLA2, as well as its catalytically inactivated form, significantly inhibited angiogenesis both in vitro and in vivo. We have also found that the actin cytoskeleton and the distribution of alphav beta3 integrin, a critical regulator of angiogenesis and a major component of focal adhesions, were disturbed after MVL-PLA2 treatment. In order to further investi...
Although rhabdomyosarcoma is the most frequent soft tissue tumor in children, there are extremely... more Although rhabdomyosarcoma is the most frequent soft tissue tumor in children, there are extremely few reports of this tumor arising from the urachus. The authors describe another case in a 6-year-old female associated with constipation and a painless suprapubic mass. The specimen had the pathological criteria used to define urachal sarcoma (cytological, histological, and immunohistochemical findings) and urachal remnants were not observed. After complete resection of the primary tumor the patient was treated with chemotherapy (ifosfamide, vincristine, and dactinomycin) and remains alive at 4 years' follow-up with no signs of recurrence. Nowadays the management of children with urachal rhabdomyosarcoma usually includes surgery and chemotherapy. Multimodal therapy and surgery are constantly evolving and have significantly improved overall survival of these patients especially in R0 resected patients.
Abstract. Our main objective was to use comparative floristic and structural criteria in order to... more Abstract. Our main objective was to use comparative floristic and structural criteria in order to understand the differences in assemblages brought about by the meeting of arid and dry-tropical environments. We sampled 33 vegetation plots and recorded all perennial species. The ...
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