Joana Afonso

α2-Adrenoceptor subtypes involved in the regulation of catecholamine release from the adrenal medulla of mice

This study was carried out to elucidate which α2‐adrenoceptor subtypes mediated the inhibition of noradrenaline and adrenaline release from the adrenal medulla of mice.

Role of superoxide and hydrogen peroxide in hypertension induced by an antagonist of adenosine receptors.

Treatment of Wistar rats for 7 days with 1,3-dipropyl-8-sulfophenylxanthine (DPSPX), an antagonist of adenosine receptors, induces long-lasting hypertension associated with marked changes in vascular structure and reactivity and renin-angiotensin system activation. This study aimed at evaluating the role of oxidative stress in the development of DPSPX-induced hypertension and also at identifying the relative contribution of superoxide radical (O2.-) vs hydrogen peroxide (H2O2). Vascular and systemic prooxidant/antioxidant status was evaluated in sham (saline, i.p., 7 days) and DPSPX (90 microg/kg/h, i.p., 7 days)-treated rats. Systolic blood pressure was determined by invasive and non-invasive methods. The activity of vascular NADPH oxidase, superoxide dismutase (SOD), catalase and glutathione peroxidase was assayed by fluorometric/spectrophotometric methods. H2O2 levels were measured using an Amplex Red Hydrogen Peroxide kit. Plasma thiobarbituric acid reactive substances and plasma antioxidant capacity were also measured. In addition we tested the effects of antioxidants or inhibitors of reactive oxygen species generation on blood pressure, vascular hyperplasia and oxidative stress parameters. DPSPX-hypertensive rats showed increased activity of vascular NADPH oxidase, SOD, catalase and glutathione peroxidase, as well as increased H2O2 generation. DPSPX-hypertensive rats also had increased plasma lipid peroxidation and decreased plasma antioxidant capacity. Treatment with apocynin (1.5 mmol/l, per os, 14 days), or with polyethylene glycol (PEG)-catalase (10,000 U/kg/day, i.p., 8 days), prevented the DPSPX-induced effects on blood pressure, vascular structure and H2O2 levels. Tempol (3 mmol/l, per os, 14 days) failed to inhibit these changes, unless PEG-catalase was co-administered. It is concluded that O2.- generation with subsequent formation of H2O2 plays a major role in the development of DPSPX-induced hypertension.

Micro Credit and Territory: Portugal as a case study

This paper studies the relations between micro credit and territory, assuming that micro credit is an important instrument for fighting against poverty and social exclusion. Based on a micro-level database provided by ANDC (Associacao Nacional de Direito ao Credito), a statistical and econometric study has been undertaken in order to identify the territorial idiosyncrasies associated with the employment of micro credit in Portugal. Focusing on the survival of micro credit projects during the period 2006-2009, our study demonstrates the significance for a firm’s survival of variables such as population density, value added growth in each activity and promoters’ qualifications, as well as two regional dummies.

Age-related changes in renal expression of oxidant and antioxidant enzymes and oxidative stress markers in male SHR and WKY rats

Oxidative stress has been hypothesized to play a role in aging and age-related disorders, such as hypertension. This study compared levels of oxidative stress and renal expression of oxidant and antioxidant enzymes in male normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR) at different ages (3 and 12 months). In the renal cortex of 3-month old SHR increases in hydrogen peroxide (H(2)O(2)) were accompanied by augmented expression of NADPH oxidase subunit Nox4 and decreased expression of antioxidant enzymes SOD1 and SOD3. A further increase in renal H(2)O(2) production and urinary TBARS was observed in 12-month old WKY and SHR as compared with 3-month old rats. Similarly, expressions of NADPH oxidase subunit p22(phox), SOD2 and SOD3 were markedly elevated with age in both strains. When compared with age-matched WKY, catalase expression was increased in 3-month old SHR, but unchanged in 12-month old SHR. Body weight increased with aging in both rat strains, but this increase was more pronounced in WKY. In conclusion, renal oxidative stress in 12-month old SHR is an exaggeration of the process already observed in the 3-month old SHR, whereas the occurrence of obesity in 12-month old normotensive rats may partially be responsible for the age-related increase in oxidative stress.

Impaired resolution of inflammation in human chronic heart failure.

Lipoxins (LXs) are proresolving and anti‐inflammatory eicosanoids whose role in chronic heart failure (CHF) pathogenesis has never been investigated. This study evaluated levels of LXs in CHF patients, its relationship with disease severity and correlation with established CHF biomarkers. The effect of low‐dose aspirin [acetylsalicylic acid (ASA)] on the levels of LXs was also studied.

Role of H2O2 in hypertension, renin‐angiotensin system activation and renal medullary disfunction caused by angiotensin II

BACKGROUND AND PURPOSE Activation of the intrarenal renin‐angiotensin system (RAS) and increased renal medullary hydrogen peroxide (H2O2) contribute to hypertension. We examined whether H2O2 mediated hypertension and intrarenal RAS activation induced by angiotensin II (Ang II).

A Systematic Review on Infliximab and Adalimumab Drug Monitoring: Levels, Clinical Outcomes and Assays.

Background:Immunogenicity to therapeutic proteins has been linked to loss of response by a large percentage of patients taking anti–tumor necrosis factor-alpha agents. Drug monitoring can be extremely useful, allowing physicians to adjust the therapeutic scheme individually. This article aims to systematically review the published data with respect to cutoff levels of infliximab (IFX) and adalimumab (ADA) and relate them to the methodology adopted for quantification of IFX and ADA levels and clinical outcomes. Methods:The PubMed database was searched to identify studies focusing on the association between IFX or ADA cutoff levels and clinical outcomes in patients with inflammatory bowel disease. Results:Of the 1654 articles initially selected by queries, 20 were included. A receiver operating characteristic curve analysis was performed to identify cutoff levels of IFX or ADA that correlated with a clinical outcome, but only 6 studies performed the same analysis for antidrug antibody levels. Cutoff levels were different between studies. The methodology chosen for level quantifications, clinical outcomes, and sample size and characteristics were also different. Nevertheless, measurement of drug levels should be performed during maintenance, and with loss of response, with persistent high levels of C-reactive protein, and when mucosal lesions are still present. In these scenarios, drug and antidrug levels were correlated with clinical outcomes. Conclusions:Concerning drug levels monitoring any methodology is adequate. With respect to antidrug antibody levels, it will be necessary to define a gold standard method or to establish different cutoff levels for different methodologies.

Proactive therapeutic drug monitoring of infliximab: a comparative study of a new point‐of‐care quantitative test with two established ELISA assays

Therapeutic drug monitoring is a powerful strategy known to improve the clinical outcomes and to optimise the healthcare resources in the treatment of autoimmune diseases. Currently, most of the methods commercially available for the quantification of infliximab (IFX) are ELISA‐based, with a turnaround time of approximately 8 h, and delaying the target dosage adjustment to the following infusion.

Correlation Between Calprotectin and Modified Rutgeerts Score.

Background:Endoscopic recurrence after surgery for Crohns disease (CD) is high, and it has important prognostic value. Crohns disease will recur in the majority of patients after surgery. Fecal calprotectin (FC) and lactoferrin (FL) have attracted interest in the postoperative setting for predicting relapse. We have evaluated the accuracy of FC and FL in diagnosing endoscopic recurrence (ER) using the modified Rutgeerts score (MRS) compared with the Rutgeerts score (RS). Methods:A series of consecutive patients who underwent ileocolonic resection for Crohns disease were evaluated. Biomarkers, clinical indexes, and fecal markers were recorded on the day of ileocolonoscopy. ER was defined as a MRS ≥ i2b or a RS ≥ i2. Results:Ninety-nine patients were included in this prospective cohort. The median time between surgery and colonoscopy was 87.5 months (IQR, 31–137). FC and FL levels were higher in patients with ER than in those in remission (Median FC, 196.5 &mgr;g/g [IQR, 96–634 &mgr;g/g] versus 42.1 &mgr;g/g [IQR 19–91.60 &mgr;g/g; P < 0.001]; Median FL, 23.27 &mgr;g/g [IQR 8.9–47.8 &mgr;g/g] versus 2 &mgr;g/g [IQR 0.9–7.26 &mgr;g/g; P < 0.001]). Using the MRS, 34% of patients presented with ER compared with 76% if the RS was used. The RS performed worse than the MRS with a decrease in sensitivity (74% versus 48% for FC and 85% versus 55% for FL) and in NPV (91% versus 33% for FC, and 90% versus 37% for FL). Furthermore, the accuracy of the MRS was higher than that of the RS (75% versus 55%). Conclusions:Both FC and FL proved to correlate well with endoscopic findings in the evaluation of Crohns disease after surgery. Both markers predicted recurrence with greater accuracy when the MRS was used. Fecal markers can be used to monitor disease recurrence after intestinal resection, with patients being selected to undergo further endoscopic evaluation.

Effect of clonidine on tyrosine hydroxylase activity in the adrenal medulla and brain of spontaneously hypertensive rats.

In the present study, we evaluated the effect of the alpha(2)-adrenoceptor agonist clonidine on tyrosine hydroxylase activity in adrenal medulla and brain of spontaneously hypertensive rats and Wistar Kyoto rats. Six-week-old animals were treated with clonidine (100 microg/kg body weight, daily, i.p.) for 4 weeks. Treatment with clonidine significantly reduced mean arterial blood pressure in spontaneously hypertensive rats to values similar to normotensive Wistar Kyoto rats. In the adrenal medulla of spontaneously hypertensive rats, clonidine treatment produced a significant increase in tyrosine hydroxylase activity with higher V(max) values and no changes in K(M) values. This effect was accompanied by a significant increase in tyrosine hydroxylase protein expression and of noradrenaline and adrenaline levels. In the brain of spontaneously hypertensive rats, treatment with clonidine produced a significant decrease in tyrosine hydroxylase activity with lower V(max) values and no changes in K(M) values accompanied by a significant decrease in tyrosine hydroxylase protein expression and of dopamine and noradrenaline levels. In Wistar Kyoto rats, clonidine treatment had no effect on tyrosine hydroxylase activity and protein expression or catecholamine levels in adrenal medulla or brain. Clonidine treatment significantly reduced noradrenaline and adrenaline plasma levels in spontaneously hypertensive rats and Wistar Kyoto rats. In conclusion, treatment with the alpha(2)-adrenoceptor agonist clonidine prevented the increase in mean arterial blood pressure in young spontaneously hypertensive rats. This effect was accompanied by opposite effects on tyrosine hydroxylase activity in spontaneously hypertensive rat adrenal medulla and brain: an increase in adrenal medulla and a decrease in brain, bringing sympathetic function to a similar profile found in normotensive Wistar Kyoto rats.