959 resultados para Military vessels.
Resumo:
BACKGROUND: Peptide receptors, overexpressed in specific cancers, represent new diagnostic and therapeutic targets. In this study, receptors for the gastrin-releasing peptide (GRP), and other members of the bombesin-family of peptides, were evaluated in ovarian neoplasms. METHODS: 75 primary, secondary and metastatic ovarian tumors were investigated for their bombesin-receptor subtype expression, incidence, localization and density using in vitro autoradiography on tissue sections with the universal radioligand (125)I-[D-Tyr(6), beta-Ala(11), Phe(13), Nle(14)]-bombesin(6-14) and the GRP-receptor subtype-preferring (125)I-[Tyr(4)]-bombesin. RESULTS: GRP-receptors were detected in 42/61 primary ovarian tumors; other bombesin-receptor subtypes (BB1, bb3) were rarely present (3/61). Two different tissue compartments expressed GRP-receptors: the tumoral vasculature was the predominant site of GRP-receptor expression (38/61), whereas neoplastic cells more rarely expressed GRP-receptors (14/61). GRP-receptor positive vessels were present in the various classes of ovarian tumors; generally, malignant tumors had a higher incidence of GRP-receptor positive vessels compared to their benign counterparts. The prevalence of such vessels was particularly high in ovarian carcinomas (16/19) and their metastases (5/5). The GRP-receptors were expressed in high density in the muscular vessel wall. Normal ovary (n=10) lacked GRP-receptors. CONCLUSIONS: The large amounts of GRP-receptors in ovarian tumor vessels suggest a role in tumoral vasculature and possibly angiogenesis. Further, these vessels might be targeted in vivo with bombesin analogs for diagnosis or for therapy.
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BACKGROUND: We examined whether vascular smooth muscle (VSMC) or endothelial cell (EC) migration from internal mammary artery (MA) differed from VSMC or EC migration from saphenous vein (SV). METHODS AND RESULTS: Migration to PDGF-BB (1-10 ng/ml) was lower in VSMC from MA than SV; however, attachment, movement without chemokine, and chemokinesis were identical. Unlike VSMC, migration of EC was similar in response to several mediators. Expression of PDGF receptor-beta was lower in VSMC from MA than SV, while alpha-receptor expression was higher. PDGF-BB-induced RhoA activity was lower in MA than SV, while basal activity was identical. Rosuvastatin and hydroxyfasudil impaired PDGF-BB-induced migration of VSMC from MA and SV. Mevalonate and geranylgeranylpyrophosphate rescued inhibition by rosuvastatin. PDGF-BB induced less stress fiber formation in VSMC from MA than SV. A dominant negative RhoA mutant inhibited stress fiber formation to PDGF-BB, while a constitutively active mutant resulted in maximal stress fiber formation in MA and SV. Rosuvastatin and hydroxyfasudil impaired PDGF-BB-induced stress fiber formation in MA and SV. CONCLUSIONS: VSMC migration to PDGF-BB is lower in MA than SV, which is at least in part related to lower activity of the Rho/ROCK pathway.
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We review the case of a 46-year-old man who underwent elective percutaneous coronary intervention and stenting of the left anterior descending artery and right coronary artery with two sirolimus- and paclitaxel-eluting stents. Four days after angioplasty, he was readmitted with cardiogenic shock due to acute anterior and inferior myocardial infarction. Coronary angiography revealed subacute thrombosis of both stents, and balloon dilation was performed successfully thereafter. The follow-up investigations revealed that the patient was a carrier of factor V Leiden. We hereby discuss the importance of factor V Leiden as the most common cause of hypercoagulable state and its probable role in acute and subacute coronary stent thrombosis in drug-eluting stents.
Resumo:
In contrast to the current belief that angiotensin II (Ang II) interacts with the sympathetic nervous system only as a circulating hormone, we document here the existence of endogenous Ang II in the neurons of rat and human sympathetic coeliac ganglia and their angiotensinergic innervation with mesenteric resistance blood vessels. Angiotensinogen - and angiotensin converting enzyme-mRNA were detected by using quantitative real time polymerase chain reaction in total RNA extracts of rat coeliac ganglia, while renin mRNA was untraceable. Cathepsin D, a protease responsible for cleavage beneath other substrates also angiotensinogen to angiotensin I, was successfully detected in rat coeliac ganglia indicating the possibility of existence of alternative pathways. Angiotensinogen mRNA was also detected by in situ hybridization in the cytoplasm of neurons of rat coeliac ganglia. Immunoreactivity for Ang II was demonstrated in rat and human coeliac ganglia as well as with mesenteric resistance blood vessels. By using confocal laser scanning microscopy we were able to demonstrate the presence of angiotensinergic synapses en passant along side of vascular smooth muscle cells. Our findings indicate that Ang II is synthesized inside the neurons of sympathetic coeliac ganglia and may act as an endogenous neurotransmitter locally with the mesenteric resistance blood vessels.
Resumo:
Carnoy's solution is applied to reduce the recurrence of odontogenic keratocysts and unicystic ameloblastomas. The deleterious action of this fixative on nerves has been studied but no attention has been paid to its effects on nearby vessels. The aim of this study was to investigate the effects of Carnoy's solution on blood vessels. The rat axillary artery and vein were surgically exposed, soaked with Carnoy's solution and kept in place for 2, 5 or 10 min, depending on the treatment group. The 5-min group was followed for 1, 2 and 3 weeks postoperatively. The vessels in the 2-min and 5-min exposure groups showed histological changes to the vessels, represented by focal loss of the endothelium and hyalinization of the wall. These alterations increased in the 10-min group. The vessels in the 3-week observation period revealed signs of recovery. It is concluded that Carnoy's solution can damage blood vessels but the process is reversible for exposure times less than 5 min.
Resumo:
The process of blood vessel proliferation, known as angiogenesis, is essential during embryonic development and organogenesis. In adult life, it participates in normal tissue repair, wound healing, and cyclical growth of the corpus luteum and the endometrium. Crucial as it is, angiogenesis can become pathological, and abnormal angiogenesis contributes to the pathogenesis of inflammatory and neoplasic diseases. The present review highlights the evidence for the role of angiogenesis in HCC (hepatocellular carcinoma) and discusses the increasing importance of inhibitors of angiogenesis in HCC therapy.
Resumo:
BACKGROUND: The aim of this study was to develop an experimental model that allows to elude the potential role of the preexisting graft microvasculature for vascularization and mineralization of osteochondral grafts. ANIMALS AND METHODS: For that purpose, the II-IV metatarsals of fetal DDY-mice known to be nonvascularized at day 16 of gestation (M16) but vascularized at day 18 (M18) were freshly transplanted into dorsal skin fold chambers of adult DDY mice. Using intravital microscopy angiogenesis, leukocyte-endothelium interaction and mineralization were assessed for 12 days. RESULTS: Angiogenesis occurred at 32 hours in M18, but not before 57 hours in M16 (p = 0.002), with perfusion of these vessels at 42 hours (p = 0.005) and 65 hours (p = 0.1), respectively. Vessels reached a density three times as high as that of the recipient site at day 6, remaining constant until day 12 in M18, whereas in M16 vascular density increased from day 6 and reached that of M18 at day 12 (p = 0.04). Leukocyte-endothelium interaction showed sticker counts elevated by a factor of 4-5 in M18 as compared to M16. Mineralization of osteochondral grafts did not differ between M16 and M18, which significantly increased in both groups throughout the observation period. INTERPRETATION: We propose the faster kinetics in the angiogenic response to M18 and the elevated counts of sticking leukocytes to rest on the potential of establishing end-to-end anastomoses (inosculation) of the vascularized graft with recipient vessels.
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We used intravascular ultrasound (IVUS) and virtual histology (VH) to assess the differences of plaque burden and composition between target coronary arteries containing the culprit lesion and non-target coronary arteries.
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BACKGROUND The long-term results after second generation everolimus eluting bioresorbable vascular scaffold (Absorb BVS) placement in small vessels are unknown. Therefore, we investigated the impact of vessel size on long-term outcomes, after Absorb BVS implantation. METHODS In ABSORB Cohort B Trial, out of the total study population (101 patients), 45 patients were assigned to undergo 6-month and 2-year angiographic follow-up (Cohort B1) and 56 patients to have angiographic follow-up at 1-year (Cohort B2). The pre-reference vessel diameter (RVD) was <2.5 mm (small-vessel group) in 41 patients (41 lesions) and ≥2.5 mm (large-vessel group) in 60 patients (61 lesions). Outcomes were compared according to pre-RVD. RESULTS At 2-year angiographic follow-up no differences in late lumen loss (0.29±0.16 mm vs 0.25±0.22 mm, p=0.4391), and in-segment binary restenosis (5.3% vs 5.3% p=1.0000) were demonstrated between groups. In the small-vessel group, intravascular ultrasound analysis showed a significant increase in vessel area (12.25±3.47 mm(2) vs 13.09±3.38 mm(2) p=0.0015), scaffold area (5.76±0.96 mm(2) vs 6.41±1.30 mm(2) p=0.0008) and lumen area (5.71±0.98 mm(2) vs 6.20±1.27 mm(2) p=0.0155) between 6-months and 2-year follow-up. No differences in plaque composition were reported between groups at either time point. At 2-year clinical follow-up, no differences in ischaemia-driven major adverse cardiac events (7.3% vs 10.2%, p=0.7335), myocardial infarction (4.9% vs 1.7%, p=0.5662) or ischaemia-driven target lesion revascularisation (2.4% vs 8.5%, p=0.3962) were reported between small and large vessels. No deaths or scaffold thrombosis were observed. CONCLUSIONS Similar clinical and angiographic outcomes at 2-year follow-up were reported in small and large vessel groups. A significant late lumen enlargement and positive vessel remodelling were observed in small vessels.