Relationship between NOX4 level and angiotensin II signaling in Gitelman's syndrome. Implications with hypertension

Recent evidence showed that endogenous nicotinamide adenine dinucleotide phosphate-oxidase 4 (NOX4) may exert a protective role on the cardiovascular system inducing vasodilation, reduction of blood pressure, and anti-proliferative actions. However, the functional significance of NOX4 in the cardiovascular system in humans remains elusive. Mononuclear cell levels of NOX4 were assessed by immunoblotting in 14 Gitelman's patients (GS), a unique human model of endogenous Ang II signaling antagonism and activation of anti-atherosclerotic and anti-remodeling defenses, and compared to 11 untreated essential hypertensive patients as well as to 11 healthy normotensive subjects. The association between NOX4 and its effector heme oxygenase (HO-1) (sandwich immunoassay) was also evaluated. NOX4 protein levels were decreased in hypertensive patients as compared to both GS and healthy subjects (1.06±0.31 AU vs. 1.76±0.54, P=0.002 and vs. 1.61±0.54, P=0.018, respectively). NOX4 protein level did not differ between GS and healthy subjects. HO-1 levels were increased in GS patients as compared to both hypertensive patients and healthy subjects (8.65±3.08 ng/ml vs 3.70±1.19, P<0.0001, and vs 5.49±1.04, P=0.008, respectively. NOX4 levels correlate with HO-1 levels only in GS (r(2)=0.63; P=0.001), (r(2)=0.088; P=ns, in hypertensive patients and r(2)=0.082; P=ns, in healthy subjects). Our findings show that NOX4 and its effector HO-1 are reduced in hypertensive patients compared to GS patients, a human model opposite to hypertension. Although the functional significance of NOX4 needs further clarification, our preliminary data in a unique human model of anti-atherosclerotic and anti-remodeling defenses activation, highlight the potentially protective role of NOX4 in the human cardiovascular system

Expression of vascular endothelial growth factor (VEGF) in equine sarcoid

Background: Sarcoids are the mostcommon skin tumors in horses, ch aracterized by rare regression, invasiveness and high recurrence following surgical intervention and Delta Papillomaviruses are widely recognized as the causative agents of the disease. In order to gain new insights into equine sarco id development, we have evaluated, in 25 equine sarcoids, by immunohistochemistry and western blotting analysis, the expression levels of VEGF, Ki67 and bcl-2. Moreover, we have measured microvessel density an d specific vessel parameters. Results: All sarcoid samples showed a strong and finely granular cytoplasmatic staining for VEGF in the majority (90%) of keratinocytes, sarcoid fibroblasts and endothelial cells. Numerous small blood vessels, immunostained with Von Willebrand factor, often appeared irregular in shape and without a distinct lumen, with mean values of microvessel area and perimeter lower than normal. Moreover, in all sarcoid samples, Ki67 immunoreactivity was moderately positive in 5 – 10% of dermal sarcoid fibroblasts, while Bcl2 immunoreactivity was detected in 52% of the sarcoid samples, with a weak staining in 20 – 50% of dermal sarcoid fibroblasts. Biochemical analysis was consistent with immunohistochemical results. Conclusions: This study has provided evidence that in equine sarcoid: VEGF was strongly expressed; the increased number of vessels was not associated with their complete maturation, probably leading to a hypoxic condition, which could increase VEGF synthesis; the levels of sarcoid fibroblasts proliferation were very low. Concluding, VEGF may have a role in equine sarcoid development, not only through the increase of angiogenesis, but also through the control of sarcoid fibroblast activity

The blocking of angiotensin II type 1 receptor and RhoA/Rho kinase activity in hypertensive patients: Effect of olmesartan medoxomil and implication with cardiovascular-renal remodeling

Hypothesis/Introduction: The pathophysiological role of oxidative stress (OxSt) in hypertension and target organ damage is recognized. Angiotensin II (Ang II) induces OxSt via NAD(P)H oxidase activation and production of proinflammatory cytokines/growth factors leading to cardiovascular-renal remodeling. Ang II stimulates the RhoA/Rho kinase (ROCK) pathway, which is deeply involved in the development of cardiovascular-renal remodeling via OxSt induction. Olmesartan, an Ang II type 1 receptor blocker, possesses antioxidant and activating nitric oxide system-related effects, which we have shown in terms of p22 phox reduction, heme oxygenase-1 and calcitonin gene-related peptide increase. This study evaluates in 15 untreated hypertensive patients the effect of olmesartan treatment on p63RhoGEF, key in Ang II-induced ROCK activation, and MYPT-1 phosphorylation, a marker of ROCK activity. Materials and methods: The p63RhoGEF protein level and MYPT-1 phosphorylation (Western blot) were evaluated at baseline, and after three and six months of olmesartan treatment. Results: Olmesartan normalized systolic and diastolic BP ( p < 0.001), reduced p63RhoGEF level: 1.3±0.25 d.u. (baseline) vs 1.0±0.29 (three months), p < 0.0001 vs 1.0±0.22, (six months), p < 0.0001 and MYPT-1 phosphorylation: 1.2 ±0.14 (baseline) vs 0.9±0.19 (three months), p = 0.008, vs 0.8±0.16 (six months), p = 0.001. Conclusions: These data added to our previous results further provide a mechanistic rationale for olmesartan's antioxidant/anti-inflammatory potential translation, in the long term, toward anti-atherosclerotic/anti-remodeling effects reported by clinical trials

Quantitative Value of Aldosterone-Renin Ratio for Detection of Aldosterone-Producing Adenoma: The Aldosterone-Renin Ratio for Primary Aldosteronism (AQUARR) Study

Current guidelines recommend use of the aldosterone-renin ratio (ARR) for the case detection of primary aldosteronism followed by confirmatory tests to exclude false-positive results from further diagnostic workup. We investigated the hypothesis that this could be unnecessary in patients with a high ARR value if the quantitative information carried by the ARR is taken into due consideration

Design of a study to investigate the mechanisms of obstructive sleep apnoea by means of drug-induced sleep endoscopy

Background Obstructive sleep apnoea (OSA) is an independent risk factor of hypertension and cardiovascular diseases. Recurrent episodes of upper airways collapse during sleep causing blood oxygen desaturation, hypercapnia, and micro-arousals, are known to activate the sympathetic nervous system (SNS). However, whether changes in the renin-angiotensin-aldosterone system and endothelial activation also occur remains contentious. Methods Based on routine use of drug-induced sleep endoscopy (DISE) for the work-up of OSA patients in our centre, we designed a prospective study to investigate the haemodynamic and humoral changes occurring during the apnoeic episodes reproduced in vivo in the course of DISE. Specifically, plasma aldosterone concentration and renin activity, C-terminal fragment of proendothelin-1, as a marker of endothelial damage, and free plasma catecholamines, will be measured at fixed times during DISE. The activity of catechol-O-methyltransferase (COMT), a key catecholamine-inactivating enzyme that has been scantly investigated thus far owing to the lack of commercially available kits, will be also determined by a newly developed high performance liquid chromatography method, which is herein described. Results and conclusions The aim of this study is to provide novel information on the haemodynamic, hormonal, and SNS changes, and also on COMT activity modification concomitantly occurring during apnoea, thus contributing substantively to the understanding of the pathophysiology of OSA

Multicenter research into the quality of life of patients with advanced oropharyngeal carcinoma with long-term survival associated with human papilloma virus

The treatment of advanced-stage oropharyngeal squamous cell carcinoma may utilize various modes, including combining surgery with chemoradiotherapy (CTRT), or primary CTRT followed by rescue surgery. In previous literature it has been revealed how patients treated with combined modes report a low quality of life (QoL) and severe consequences following surgery, radiotherapy and chemotherapy, in the short and in the long-term. The decrease in the QoL of patients treated with high-intensity multi-modal strategies highlights the necessity of modifying treatments, particularly for young HPV-positive patients, where an increased survival rate has already been reported. The modified treatment for HPV-positive tumors in the tonsils and at the base of the tongue is based on the deintensification of therapies aiming to reduce toxicity and thereby improve QoL in the long term, whilst still maintaining therapeutic effectiveness. The aim of the present study was to evaluate the QoL in patients with a long-term survival, who were treated with combined therapy for squamous cell tumors in the tonsils and at the base of the tongue, and to compare the results observed in HPV-positive and HPV-negative patients. According to statistical analysis, differences in the general QoL and in the single scales of the European Organization for the Research and Treatment of Cancer questionnaires were not correlated with the type of therapy selected for the particular patient. QoL considered the presence of HPV, the type of treatment, the subregion of the tonsils vs. the base of the tongue and the disease stage at the time of diagnosis, and was determined to be non-influential with regard to these specific variables

Quantitative value of aldosterone-renin ratio for detection of aldosterone-producing adenoma: The Aldosterone-Renin Ratio for Primary Aldosteronism (AQUARR) study

Background Current guidelines recommend use of the aldosterone\u2010renin ratio (ARR) for the case detection of primary aldosteronism followed by confirmatory tests to exclude false\u2010positive results from further diagnostic workup. We investigated the hypothesis that this could be unnecessary in patients with a high ARR value if the quantitative information carried by the ARR is taken into due consideration. Methods and Results We interrogated 2 large data sets of prospectively collected patients studied with the same predefined protocol, which included the captopril challenge test. We used an unambiguous diagnosis of aldosterone\u2010producing adenoma as reference index. We also assessed whether the post\u2010captopril ARR and plasma aldosterone concentration fall furnished a diagnostic gain over baseline ARR values. We found that the false\u2010positive rate fell exponentially, and, conversely, the specificity increased with rising ARR values. At receiver operating characteristics curves and diagnostic odds ratio analysis, the high baseline ARR values implied very high positive likelihood ratio and diagnostic odds ratio values. The baseline and post\u2010captopril ARR showed similar diagnostic accuracy (area under the receiver operating characteristics curve) in both the exploratory and validation cohorts, indicating lack of diagnostic gain with this confirmatory test (between\u2010area under the curve difference, 0.005; 95% CI, 120.031 to 0.040; P=0.7 for comparison, and 0.05; 95% CI, 120.061 to 0.064; P=0.051 for comparison, respectively). Conclusions These results indicate that the ARR conveys key quantitative information that, if properly used, can simplify the diagnostic workup, resulting in saving of money and resources. This can offer the chance of diagnosis and ensuing adrenalectomy to a larger number of hypertensive patients, ultimately resulting in better control of blood pressure