The glucagon-like Peptide-2

Multiple peptide hormones produced within the gastrointestinal system act also in the central nervous system and aid in the regulation of energy homeostasis and metabolism. The list of these peptides is progressively increasing and includes glucagon-like peptide 2 (GLP-2) as an anorexigenic factor. GLP-2 is released from enteroendocrine L-cells following food intake and its principal target is represented by the gastrointestinal tract. GLP-2 has been shown to be an important intestinotrophic factor that stimulates epithelial cell proliferation and inhibits apoptosis. GLP-2 increases intestinal blood flow and the activity and expression of epithelial brush-border digestive enzymes and nutrient transporters, and consequently increases the intestinal digestive and absorptive capacity. It inhibits gastric and intestinal motility, thus providing another mechanism to increase absorption of nutrients. Current research has focused on determining its physiological actions and its biological mechanisms in the gut, while very little is known on the GLP-2 actions within the brain. This review provides an overview of the state of the art on GLP-2 biology.peer-reviewe

Near Optimal Channel Assignment for Interference Mitigation in Wireless Mesh Networks

In multi-radio multi-channel (MRMC) WMNs, interference alleviation is affected through several network design techniques e.g., channel assignment (CA), link scheduling, routing etc., intelligent CA schemes being the most effective tool for interference mitigation. CA in WMNs is an NP-Hard problem, and makes optimality a desired yet elusive goal in real-time deployments which are characterized by fast transmission and switching times and minimal end-to-end latency. The trade-off between optimal performance and minimal response times is often achieved through CA schemes that employ heuristics to propose efficient solutions. WMN configuration and physical layout are also crucial factors which decide network performance, and it has been demonstrated in numerous research works that rectangular/square grid WMNs outperform random or unplanned WMN deployments in terms of network capacity, latency, and network resilience. In this work, we propose a smart heuristic approach to devise a near-optimal CA algorithm for grid WMNs (NOCAG). We demonstrate the efficacy of NOCAG by evaluating its performance against the minimal-interference CA generated through a rudimentary brute-force technique (BFCA), for the same WMN configuration. We assess its ability to mitigate interference both, theoretically (through interference estimation metrics) and experimentally (by running rigorous simulations in NS-3). We demonstrate that the performance of NOCAG is almost as good as the BFCA, at a minimal computational overhead of O(n) compared to the exponential of BFCA

Il diritto di accesso ai documenti amministrativi

Il presente lavoro si pone come obiettivo quello di compiere un'analisi storica ed evolutiva dell'istituto del diritto di accesso ai documenti amministrativi. Si sono previsti sei capitoli che partono da una valutazione attenta ed accurata dell'istituto prima e dopo l'avvento delle ultimissime riforme in materia. Si pone l'accento su diverse tematiche in primis sull'oggetto, per poi soffermarsi sui soggetti (attivi e passivi) coinvolti nel procedimento, trattando istituti di recente introduzione come l'accesso civico. A seguire si espone con molta attenzione il limite della riservatezza, soffermandosi su quelli che sono i veri limiti al diritto di accesso esaminando con accuratezza la tematica della privacy, del segreto, della tutela dei dati sanitari, degli atti ambientali e degli enti locali. L'epilogo non può che trattare della fase relativa alla tutela contro il diniego di accesso, partendo da una tutela amministrativa, con la facoltà di ricorso alla Commissione per l'accesso, si procede individuando i profili civilistici e penalistici di responsabilità, anche citando la più recente giurisprudenza in materia, in ultimo si tratta di una realtà in continua evoluzione ovvero della tutela a livello europeo trattando i più recenti perfezionamenti in materi

Renal involvement in psychological eating disorders

Psychological eating disorders--anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder--are an increasing public health problem with severe clinical manifestations: hypothermia, hypotension, electrolyte imbalance, endocrine disorders and kidney failure; they are of interest to nephrologists, but pathophysiological mechanisms in determining the renal involvement are still unclear. We describe pathophysiology, histological features and clinical manifestations of the most frequent psychological eating disorders: AN and BN. Regarding AN, we analyze the recent literature, and identify 3 principal pathways towards renal involvement: chronic dehydration-hypokalemia, nephrocalcinosis and chronic rhabdomyolysis. Regarding BN, we describe the correlation between obesity and many proinflammatory cytokines, chemokines, growth factors and adipokines, having potential metabolic and hemodynamic effects on the kidney and an important role in the pathogenesis of obesity-related renal injury, independently of hypertension and diabetes

Glucagon-Like Peptide-1 Modulates Neurally-Evoked Mucosal Chloride Secretion in Guinea Pig Small Intestine In Vitro.

Glucagon-like peptide-1 (GLP-1) acts at the G protein-coupled receptor, GLP-1R, to stimulate secretion of insulin and to inhibit secretion of glucagon and gastric acid. Involvement in mucosal secretory physiology has received negligible attention. We aimed to study involvement of GLP-1 in mucosal chloride secretion in the small intestine. Ussing chamber methods, in concert with transmural electrical field stimulation (EFS), were used to study actions on neurogenic chloride secretion. ELISA was used to study GLP-1R effects on neural release of acetylcholine (ACh). Intramural localization of GLP-1R was assessed with immunohistochemistry. Application of GLP-1 to serosal or mucosal sides of flat-sheet preparations in Ussing chambers did not change baseline short-circuit current (Isc), which served as a marker for chloride secretion. Transmural EFS evoked neurally mediated biphasic increases in Isc that had an initial spike-like rising phase followed by a sustained plateau-like phase. Blockade of the EFS-evoked responses by tetrodotoxin indicated that the responses were neurally mediated. Application of GLP-1 reduced the EFS-evoked biphasic responses in a concentration-dependent manner. The GLP-1 receptor antagonist exendin-(9 –39) suppressed this action of GLP-1. The GLP-1 inhibitory action on EFS-evoked responses persisted in the presence of nicotinic or vasoactive intestinal peptide receptor antagonists but not in the presence of a muscarinic receptor antagonist. GLP-1 significantly reduced EFS-evoked ACh release. In the submucosal plexus, GLP-1R immunoreactivity (IR) was expressed by choline acetyltransferase- IR neurons, neuropeptide Y-IR neurons, somatostatin-IR neurons, and vasoactive intestinal peptide-IR neurons. Our results suggest that GLP-1R is expressed in guinea pig submucosal neurons and that its activation leads to a decrease in neurally evoked chloride secretion by suppressing release of ACh at neuroepithelial junctions in the enteric neural networks that control secretomotor functions

The referral centers for the diagnosis and treatment of hypertension in adolescents

Primary hypertension in adolescence was felt to be quite rare. However, the worldwide childhood obesity epidemic has had a profound impact on the frequency of high blood pressure (BP) with the result that primary hypertension should now be viewed as one of the most common health conditions in the young (estimated prevalence 1–5%). Therefore, current guidelines recommend that all children and adolescents seen in a medical setting should have their BP measured. The availability of BP tables with normal BP percentiles for age, sex and height has improved BP values classification. Studies conducted at referral clinics for evaluation of hypertension have indicated that as many as 30 to 40% of adolescents may actually have in a clinical setting white-coat hypertension. This may lead to a misdiagnosis of “true” hypertension in a considerable number of cases. The usefulness of out-of-office BP evaluation using ambulatory or home monitoring is well established. These measurements allow the detection of the white-coat and masked hypertension, the opposite of white-coat hypertension, and are more closely associated with organ damage and cardiovascular risk than office measurements. A thorough familial and personal history is of primary importance as well as the physical examination that should be focused on the search for signs suggestive for an underlying cause and/or for the severity of hypertension. Following investigations must be tailored to the child’s age, anamnesis and clinical examination and to the severity of BP elevation, in order to investigate not only the possible cause of hypertension, but also associated diseases and target organs damage. Therapeutic approach should firstly include non-pharmacological measures, and the use of medications when indicated. A key role in the management of the adolescents with hypertension may be attributed to the hypertension referral center

Angiotensin II contractile effects in mouse colon: role for pre- and post-junctional AT1A receptors

Aim: This study investigates whether a local renin–angiotensin system (RAS) exists in mouse colon and whether angiotensin II (Ang II) may play a role in the regulation of the contractile activity. Methods: Isometric recordings were performed in vitro on the longitudinal muscle of mouse proximal and distal colon. Transcripts encoding for RAS components were investigated by RT-PCR. Results: Ang II caused, in both preparations, a concentration-dependent contractile effect, antagonized by losartan, AT1 receptor antagonist, but not by PD123319, AT2 receptor antagonist. The combination of losartan plus PD123319 caused no change on the Ang II-induced contraction than losartan alone. Tetrodotoxin, neural blocker, reduced the contractile response to Ang II in the proximal colon, whilst the response was abolished in the distal colon. In both preparations, atropine, muscarinic receptor antagonist, or SR140333, NK1 receptor antagonist, reduced the Ang II responses. Ondansetron, 5-HT3 receptor antagonist, SR48968, NK2 receptor antagonist, or hexamethonium, nicotinic receptor antagonist, were ineffective. The joint application of atropine and SR140333 produced no additive effect. Atropine reduced NK1-induced contraction. Transcripts encoding RAS components were detected in the colon samples. However, just AT1A mRNA was expressed in both preparations, and AT2 mRNA was expressed only in the distal colon. Conclusion: In the murine colon, local RAS may play a significant role in the control of contractile activity. Ang II positively modulates the spontaneous contractile activity via activation of post-junctional and pre-junctional AT1A receptors, the latter located on the enteric neurones, modulating the release of tachykinins and acetylcholine