Immunohistochemical evaluation of prostaglandin E2 and vascular endothelial growth factor in canine cutaneous mast cell tumours

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

IFPA Meeting 2010 Workshop Report I: Immunology; Ion transport; Epigenetics; Vascular reactivity; Epitheliochorial placentation; Proteomics

Workshops are an important part of the IFPA annual meeting. At IFPA Meeting 2010 there were twelve themed workshops, six of which are summarized in this report 1. The immunology workshop focused on normal and pathological functions of the maternal immune system in pregnancy. 2. The transport workshop dealt with regulation of ion and water transport across the syncytiotrophoblast of human placenta. 3. The epigenetics workshop covered DNA methylation and its potential role in regulating gene expression in placental development and disease. 4. The vascular reactivity workshop concentrated on methodological approaches used to study placental vascular function. 5. The workshop on epitheliochorial placentation covered current advances from in vivo and in vitro studies of different domestic species. 6. The proteomics workshop focused on a variety of techniques and procedures necessary for proteomic analysis and how they may be implemented for placental research. (C) 2011 Published by IFPA and Elsevier Ltd.

Biodegradable Nanoparticles Containing Benzopsoralens: An Attractive Strategy for Modifying Vascular Function in Pathological Skin Disorders

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Papel da regiao AV3V no choque septico experimental em ratos tratados com NaCl 7,5%

The effect of intravenous infusion of hypertonic saline (HS) on the recovery of mean arterial pressure (MAP) during septic shock was studied in sham-operated rats and in rats with electrolytic lesion in the anteroventral third ventricle (AV3V) region. Our results show that intravenous HS infusion in rats treated with endotoxin (Etx) partially restores MAP, but when we have a severe shock produced by Etx, HS was not able to reverse the hypotension. We also show that the integrity of the AV3V region is essential for the protective action of HS in endotoxin shock. It is possible that NO production contributes to the deleterious effect of endotoxin. So, the unraveling of the release of NO by the vascular endothelium and their role as regulators of vascular tone is increasing our understanding of the physiology and pathophysiology of the cardiovascular system and will therefore enhance the possibilities of preventing and treating endotoxin shock.

Structural characteristics of the superior venae cavae wall at the intrapericardium segment in adults and aging individuals

The authors admit that the conjunctive-muscular constitution of the walls of the superior venae cavae throughout the length of the intrapericardium segment and the debouchement in the right atrium, associated with the presence of a myocardium sheath can be made up of a functional device of sphincter form able to act on the control of the blood flow to the interior of the arterial chamber as well as stopping blood flow during the arterial systole. The fixation of the venous wall to the deep chamber of the serous pericardium, contributes to growth in resistance during the elevation of venous pressure, making possible the preservation of integrity of the superior venae cavae. The expansion of fasciculi of nodal fibers in the right wall of the superior venae cavae permits that the unlocked impulse in the S-A node also reaches the vascular wall contributing to the shortening and diminution in caliber of the vein.

Effect of NωNLA or dexamethasone on vascular hyporeactivity induced by E. coli endotoxin in sham and adrenalectomized rats

Induction of iNOS by bacterial products is considered to be part of the defense mechanism against infection. However, it has been suggested that the bacterial-induced NO-overproduction may be involved in the vascular hyporeactivity and in septic shock. It is well known that glucocorticoids prevent the induction of iNOS by Etx in rats. In the present study, dexamethasone diminished but not abolished Etx-induced vascular hyporeactivity in rats. Our results showed that the inhibition of iNOS protects sham rats against the lethal shock produced by Etx, but, in Adx rats, the NωNLA, an iNOS inhibitor, did not reduce Etx-induced mortality. Interestingly, the lack of glucocorticoid impaired the protective effect of NωNLA against Etx-induced hyporeactivity and shock in rats. A conceivable pharmacological approach to protect tissues against deleterious effect of excessive NO production includes inhibition of the iNOS, because the absence of glucocorticoid may increase the iNOS gene expression, with NO-overproduction induced by Etx, suggesting that the glucocorticoids might be of therapeutic value for the treatment of hyporeactivity and shock triggered by sepsis.

Carbon isotope composition and leaf anatomy as a tool to characterize the photosynthetic mechanism of Artemisia annua L.

Leaves of Artemisia annua L. are a plentiful source of artemisinin, a drug with proven effectiveness against malaria. The aim of this study was to classify the photosynthetic mechanism of A. annua through studies of the carbon isotope composition (δ 13C) and the leaf anatomy. A. annua presented a δ 13C value of - 31.76 ± 0.07, which characterizes the plants as a typical species of the C3 photosynthethic mechanism, considering that the average δ 13C values for C3 and C4 species are -28 and -14, respectively. The leaf anatomy studies were consistent with the δ 13C results, where, in spite of the existence of parenchymatic cells forming a sheath surrounding the vascular tissue, the cells do not contain chloroplasts or starch. This characteristic is clearly different from that of the Kranz anatomy found in C4 species.

Diversity of vascular plants growing on walls of a Brazilian city

City walls are very specialized environments, conditioned by human activities. There is little information about plants that invade human-made habitats, and no study done in Brazil with plants growing up on walls. The aim of the present study was to survey the wall vascular flora of a Brazilian city, comparing the diversity found in its downtown and neighborhoods. Fieldwork was done in Jundiaí, São Paulo State, where data was collected in downtown and in five neighborhoods. In each place, three transects of 1 km were established and every plant individual was registered. Twenty-eight species were identified, all of them on the downtown transect and most also on the neighborhood transects. Five species were the most frequent, although none were dominant. The diversity indicies of the six transects were not significantly different, with an overall diversity of H′ = 2.93. © Springer Science + Business Media, Inc. 2006.

Central nitric oxide modulates hindquarter vasodilation elicited by AMPA receptor stimulation in the NTS of conscious rats

Microinjection of S-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) in the nucleus of the solitary tract (NTS) of conscious rats causes hypertension, bradycardia, and vasoconstriction in the renal, mesenteric, and hindquarter vascular beds. In the hindquarter, the initial vasoconstriction is followed by vasodilation with AMPA doses >5 pmol/100 nl. To test the hypothesis that this vasodilation is caused by activation of a nitroxidergic pathway in the NTS, we examined the effect of pretreatment with the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME, 10 nmol/100 nl, microinjected into the NTS) on changes in mean arterial pressure, heart rate, and regional vascular conductance (VC) induced by microinjection of AMPA (10 pmol/100 nl in the NTS) in conscious rats. AMPA increased hindquarter VC by 18 ± 4%, but after pretreatment with L-NAME, AMPA reduced hindquarter VC by 16 ± 7% and 17 ± 9% (5 and 15 min after pretreatment, P < 0.05 compared with before pretreatment). Pretreatment with L-NAME reduced AMPA-induced bradycardia from 122 ± 40 to 92 ± 32 beats/min but did not alter the hypertension induced by AMPA (35 ± 5 mmHg before pretreatment, 43 ± 6 mmHg after pretreatment). Control injections with D-NAME did not affect resting values or the response to AMPA. The present study shows that stimulation of AMPA receptors in the NTS activates both vasodilatatory and vasoconstrictor mechanisms and that the vasodilatatory mechanism depends on production of nitric oxide in the NTS. Copyright © 2006 the American Physiological Society.

Risk factors for vascular dementia in elderly psychiatric outpatients with preserved cognitive functions

The aim of the study was to assess risk factors for vascular dementia (VaD) in elderly psychiatric outpatients without dementia, and to determine to what extent clinical interventions targeted such risk factors. Out of 250 clinical charts, 78 were selected of patients over 60 years old, who showed no signs of dementia. Information was obtained regarding demographics, clinical conditions (diagnosis according to ICD-10), complementary investigation, cognitive functions (via CAMCOG), neuroimaging, and the presence of risk factors for VaD. Depression was the most prevalent psychiatric disorder (74%). A great majority of the patients (86%) had at least one risk factor for VaD. One-third of the sample showed three or more risk factors for VaD. The clinical conditions related to risk factors for VaD were hypertension (48.7%), heart disease (30.8%), hypercholesterolemia (25.6%), diabetes mellitus (23.1%), stroke (12.8%), tryglyceride (12.8%), and obesity (5.1%). In terms of lifestyle, smoking (19.2%), alcohol abuse (16.7%), and sedentarism (14.1%) were other risk factors found. Definite risk factors for VaD were found in 83.3% of the patients. Previous interventions targeting risk factors were found in only 20% of the cases. The high rates of risk factors for VaD identified in this sample suggest that psychiatrists should be more attentive to these factors for the prevention of VaD. © 2007 Elsevier B.V. All rights reserved.

Vascular hyporeactivity to angiotensin II induced by Escherichia coli endotoxin is reversed by Nω-Nitro-L-Arginine, an inhibitor of nitric oxide synthase

Septic shock or sepsis is reported to be one of the major causes of death when followed by systemic infectious trauma in humans and other mammals. Its development leads to a large drop in blood pressure and a reduction in vascular responsiveness to physiological vasoconstrictors which, if not contained, can lead to death. It is proposed that this vascular response is due to the action of bacterial cell wall products released into the bloodstream by the vascular endothelium and is considered a normal response of the body's defenses against infection. A reduction in vascular reactivity to epinephrine and norepinephrine is observed under these conditions. In the present study in rats, the aim was to assess whether those effects of hypotension and hyporeactivity are also related to another endogenous vasoconstrictor, angiotensin II (AII). We evaluated the variation in the power of this vasoconstrictor over the mean arterial pressure in anesthetized rats, before and after the establishment of hypotension by Escherichia coli endotoxin (Etx). Our results show that in this model of septic shock, there is a reduction in vascular reactivity to AII and this reduction can be reversed by the inhibitor of nitric oxide synthase, Nω-Nitro-L- Arginine (NωNLA). Our results also suggest that other endogenous factors (not yet fully known) are involved in the protection of rats against septic shock, in addition to the L-arginine NO pathway.

Immunohistochemical, tomographic and histological study on onlay iliac grafts remodeling

The information concerning the molecular events taking place in onlay bone grafts are still incipient. The objective of the present study is to correlate the effects of perforation of resident bone bed on (1) the timing of onlay autogenous graft revascularization; (2) the maintenance of volume/density of the graft (assessed through tomography); and (3) the occurrence of bone remodeling proteins (using immunohistochemistry technique) delivered in the graft. Thirty-six New Zealand White rabbits were subjected to iliac crest onlay bone grafting on both sides of the mandible. The bone bed was drill-perforated on one side aiming at accelerating revascularization, whereas on the other side it was kept intact. After grafts fixation and flaps suture all animals were submitted to tomography on both mandible sites. Six animals were sacrificed, respectively, at 3, 5, 7, 10, 20 and 60 days after surgery. A second tomography was taken just before sacrifice. Histological slides were prepared from each grafted site for both immunohistochemistry analysis [osteopontin, osteocalcin, type I collagen and vascular endothelial growth factor (VEGF) anti-bodies] and histometric analysis. The values on bone volume measured on tomography showed no statistic significance (P≥0.05) between perforated and intact sites. Grafts placed on perforated beds showed higher bone density values compared with non-perforated ones at 3 days (P≤0.05). This correlation was inverted at 60 days postoperatively. The findings from VEGF labeling revealed a tendency for earlier revascularization in the perforated group. The early revascularization of bone grafts accelerated the bone remodeling process (osteocalcin, type I collagen and osteopontin) that led to an increased bone deposition at 10 days. The extended osteoblast differentiation process at intermediate stages in the perforated group cooperated for a denser bone at 60 days. © 2008 Blackwell Munksgaard.

Mecanismo de centralização: Da insuficiência placentária à adaptação circulatória fetal

The application and development of obstetric Dopplervelocimetry provide a basis for the investigation of placental insuf ciency and demonstrate the dynamic behavior of fetal circulation during hypoxia. In clinical practice, assessing hemodynamics in three vascular regions involved in pregnancy, namely the uterine, umbilical and middle cerebral arteries, has become routine. Roughly, the cerebral artery expresses the balance between uterine artery oxygen supply and umbilical artery oxygen uptake. Currently, when such balance is unfavorable, the fetal cardiac reserve is investigated by assessing the venous duct. However, determining and interpreting vascular resistance indexes is not an easy task. The starting point is to know the physiopathology of placental insuf ciency and fetal circulatory adaptation through which Doppler con rmed its role in the assessment of fetal well-being.

Exercise training improves relaxation response and SOD-1 expression in aortic and mesenteric rings from high caloric diet-fed rats

Background. Obesity has been associated with a variety of disease such as type II diabetes mellitus, arterial hypertension and atherosclerosis. Evidences have shown that exercise training promotes beneficial effects on these disorders, but the underlying mechanisms are not fully understood. The aim of this study was to investigate whether physical preconditioning prevents the deleterious effect of high caloric diet in vascular reactivity of rat aortic and mesenteric rings. Methods. Male Wistar rats were divided into sedentary (SD); trained (TR); sedentary diet (SDD) and trained diet (TRD) groups. Run training (RT) was performed in sessions of 60 min, 5 days/week for 12 weeks (70-80% VO2max). Triglycerides, glucose, insulin and nitrite/nitrate concentrations (NOx -) were measured. Concentration- response curves to acetylcholine (ACh) and sodium nitroprusside (SNP) were obtained. Expression of Cu/Zn superoxide dismutase (SOD-1) was assessed by Western blotting. Results. High caloric diet increased triglycerides concentration (SDD: 216 ± 25 mg/dl) and exercise training restored to the baseline value (TRD: 89 ± 9 mg/dl). Physical preconditioning significantly reduced insulin levels in both groups (TR: 0.54 ± 0.1 and TRD: 1.24 ± 0.3 ng/ml) as compared to sedentary animals (SD: 0.87 ± 0.1 and SDD: 2.57 ± 0.3 ng/ml). On the other hand, glucose concentration was slightly increased by high caloric diet, and RT did not modify this parameter (SD: 126 ± 6; TR: 140 ± 8; SDD: 156 ± 8 and TRD 153 ± 9 mg/dl). Neither high caloric diet nor RT modified NO x - levels (SD: 27 ± 4; TR: 28 ± 6; SDD: 27 ± 3 and TRD: 30 ± 2 μM). Functional assays showed that high caloric diet impaired the relaxing response to ACh in mesenteric (about 13%), but not in aortic rings. RT improved the relaxing responses to ACh either in aortic (28%, for TR and 16%, to TRD groups) or mesenteric rings (10%, for TR and 17%, to TRD groups) that was accompanied by up-regulation of SOD-1 expression and reduction in triglycerides levels. Conclusion. The improvement in endothelial function by physical preconditioning in mesenteric and aortic arteries from high caloric fed-rats was directly related to an increase in NO bioavailability to the smooth muscle mostly due to SOD-1 up regulation. © 2008 de Moraes et al; licensee BioMed Central Ltd.