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71.
72.
Bolontrade MF; Stern MC; Binder RL; Zenklusen JC; Gimenez-Conti IB; Conti CJ 《Carcinogenesis》1998,19(12):2107-2113
In this study we have analyzed the vascular response induced in the two-
stage carcinogenesis model in SENCAR mice. The role of angiogenesis has not
been explored in this model, which is the paradigm of multistage
carcinogenesis and a model for neoplastic lesions derived from exophytic
premalignant lesions (e.g. colon carcinoma, bladder papilloma). We
investigated if angiogenesis is involved in the formation of papillomas and
in the progression from papilloma to carcinoma. To this end we analyzed the
vasculature of normal and hyperplastic skin, focal epidermal hyperplasias
that are precursors of papillomas, papillomas at different stages and
squamous cell carcinomas. We also analyzed the vascularization of
papillomas induced in two strains of mice that differ in their
susceptibility to malignant progression. We show here that angiogenesis is
turned on in the earliest stages of papilloma formation. In late stages,
regardless of state of progression, the predominant response is an increase
in the size of blood vessels. Thus, in the SENCAR mouse model,
representative of exophytic tumors, the angiogenesis switch is a very early
event, probably mechanistically related to the development of the primarily
exophytic lesions. Therefore, the density of blood vessels cannot be used
as a predictor of malignant progression in this model.
相似文献
73.
Teixeira AB Etchebehere CS Carvalho DC Sousa MC Santos AO Lima MC Ramos CD Camargo EE 《Clinical nuclear medicine》2000,25(6):484
A 47-year-old woman with adenocarcinoma of the right breast had bone scintigraphy with Tc-99m MDP. Bone imaging did not show any metastases. However, a large area of increased tracer uptake was seen extending from the abdomen to the pelvis. Abdominal ultrasound revealed a large solid and heterogeneous mass, measuring 18 x 11 x 14.3 cm, that originated in an empty uterus. A biopsy of the surgical specimen showed a leiomyoma of the uterus. 相似文献
74.
75.
Socorro Vanesca Frota Madeira Angela de Castro Resende Dayane Teixeira Ognibene Marcelo Augusto Vieira de Sousa Roberto Soares de Moura 《Pharmacological research》2005,52(4):321-327
An alcohol-free grape-skin extract (GSE) obtained from skins of Vitis labrusca has significant anti-hypertensive, antioxidant and vasodilator effects. According to our previous results, the vasodilator effect of GSE in the isolated mesenteric vascular bed (MVB) of the rat is dependent on endothelium and partially dependent on nitric oxide (NO). In the MVB of the rat pre-contracted with norepinephrine (NE), bolus injections of GSE induced a long-lasting dose-dependent vasodilation that is significantly reduced after the treatment with 1H-[1,2,3] oxadiazolo [4,4-a] quinoxalin-1-one (ODQ). Additionally, in vessels pre-contracted with norepinephrine and depolarized with KCl (25 mM) or treated with Ca(2+)-dependent K(+)-channel blockers charybdotoxin (ChTx) plus apamin, the vasodilator effect of GSE was significantly reduced and almost abolished by ChTx plus apamin plus L-NAME. However, the vasodilator effect of GSE was unaffected by D-Arg[Hyp(3),Thi(5),D-Tic(7),Oic(8)]bradykinin (HOE-140), atropine, yohimbine, pyrilamine and 4-aminopyridine (4-AP). The vasoconstriction response elicited by bolus injection of KCl was not affected by GSE, whereas the vasoconstrictor response induced by NE was dose-dependently and completed inhibited by GSE in the presence but not in the absence of endothelium. However, NE-induced vasoconstriction in calcium-free condition or without endothelium was not reduced by GSE. The present results demonstrate that GSE induces a vasodilator effect in the rat MVB, which is dependent on NO in combination with endothelium-derived hyperpolarizing factor (EDHF). Additionally, our results indicated that extracellular Ca(2+) has an important role on the endothelium-dependent vasodilator effect induced by GSE. 相似文献
76.
Juliana Pavan Zuliani José María Gutiérrez Luciana Lyra Casais e Silva Sandra Coccuzzo Sampaio Bruno Lomonte Catarina de Fátima Pereira Teixeira 《Toxicon》2005,46(5):523-532
The in vitro effects of myotoxin III (MT-III), an Asp-49 catalytically-active phospholipase A(2), and myotoxin II (MT-II), a catalytically-inactive Lys-49 variant, isolated from Bothrops asper snake venom, on phagocytosis and production of hydrogen peroxide (H(2)O(2)) by thioglycollate-elicited macrophages were investigated. MT-II and MT-III were cytotoxic to mouse peritoneal macrophages at concentrations higher than 25 microg/ml. At non-cytotoxic concentrations, MT-II stimulated Fcgamma, complement, mannose and beta-glucan receptors-mediated phagocytosis, whereas MT-III stimulated only the mannose and beta-glucan receptors-mediated phagocytosis. Moreover, both myotoxins induced the release of H(2)O(2) by thioglycollate-elicited macrophages, MT-III being the most potent stimulator. MT-II induced the release of H(2)O(2) only at a concentration of 3.2 microg/ml (130% increment) while MT-III induced this effect at all concentrations tested (0.5-2.5 microg/ml; average of 206% increment). It is concluded that, at non-cytotoxic concentrations, MT-II and MT-III activate defense mechanisms in macrophages up regulating phagocytosis, mainly via mannose and beta-glucan receptors, and the respiratory burst. 相似文献
77.
Stella Regina Zamuner Juliana Pavan Zuliani Cristina Maria Fernandes José Maria Gutiérrez Catarina de Fátima Pereira Teixeira 《Toxicon》2005,46(7):806-813
Bothrops asper venom (BaV) causes systemic and local effects characterized by an acute inflammatory reaction with accumulation of leukocytes and release of endogenous mediators. In this study, the effects of BaV on the release of the cytokines IL-1, IL-6 and TNF-alpha and the eicosanoids LTB4 and TXA2 in the peritoneal cavity of mice were analyzed. We also investigated the participation of beta2 integrin chain, l-selectin, LFA-1, ICAM-1 and PECAM-1 adhesion molecules in the BaV-induced leukocyte accumulation. Levels of proinflammatory cytokines IL-6 and TNF-alpha, as well as eicosanoids LTB4 and TXA2 were significantly increased after BaV injection (250 microg/kg), whereas no increment in IL-1 was observed. Anti-mouse l-selectin, LFA-1, ICAM-1, PECAM-1 and beta2 integrin chain monoclonal antibodies resulted in a reduction of neutrophil accumulation induced by BaV injection compared with isotype-matched control injected animals. These data suggest that BaV is able to induce the activation of leukocytes and endothelium to express adhesion molecules involved in the recruitment of neutrophils into the inflammed site. Furthermore, these results showed that BaV induces the release of cytokines and eicosanoids in the local of the venom injection; these inflammatory mediators may be important for the initiation and amplification of the inflammatory reaction characteristic from Bothrops sp envenomation. 相似文献
78.
Jos V. dos Santos Patricia F. Freixo islan de C. Vivarini Jorge M. Medina Lucio A. Caldas Marcia Attias Karina L. Dias Teixeira Teresa Cristina C. Silva Ulisses G. Lopes 《Viruses》2022,14(9)
Viral coinfections can modulate the severity of parasitic diseases, such as human cutaneous leishmaniasis. Leishmania parasites infect thousands of people worldwide and cause from single cutaneous self-healing lesions to massive mucosal destructive lesions. The transmission to vertebrates requires the bite of Phlebotomine sandflies, which can also transmit Phlebovirus. We have demonstrated that Leishmania infection requires and triggers the Endoplasmic stress (ER stress) response in infected macrophages. In the present paper, we tested the hypothesis that ER stress is increased and required for the aggravation of Leishmania infection due to coinfection with Phlebovirus. We demonstrated that Phlebovirus Icoaraci induces the ER stress program in macrophages mediated by the branches IRE/XBP1 and PERK/ATF4. The coinfection with L. amazonensis potentiates and sustains the ER stress, and the inhibition of IRE1α or PERK results in poor viral replication and decreased parasite load in macrophages. Importantly, we observed an increase in viral replication during the coinfection with Leishmania. Our results demonstrated the role of ER stress branches IRE1/XBP1 and PERK/ATF4 in the synergic effect on the Leishmania increased load during Phlebovirus coinfection and suggests that Leishmania infection can also increase the replication of Phlebovirus in macrophages. 相似文献
79.