Grapefruit-seed extract attenuates ethanol-and stress-induced gastric lesions via activation of prostaglandin, nitric oxide and sensory nerve pathways

AIM: Grapefruit-seed extract (GSE) containing flavonoids, possesses antibacterial and antioxidative properties but whether it influences the gastric defense mechanism and gastroprotection against ethanol- and stress-induced gastric lesions remains unknown. METHODS: We compared the effects of GSE on gastric mucosal lesions induced in rats by topical application of 100% ethanol or 3.5 h of water immersion and restraint stress (WRS) with or without (A) inhibition of cyclooxygenase (COX)-1 activity by indomethacin and rofecoxib, the selective COX-2 inhibitor, (B) suppression of NO-synthase with L-NNA (20 mg/kg ip), and (C) inactivation by capsaicin (125 mg/kg sc) of sensory nerves with or without intragastric (ig) pretreatment with GSE applied 30 min prior to ethanol or WRS. One hour after ethanol and 3.5 h after the end of WRS, the number and area of gastric lesions were measured by planimetry, the gastric blood flow (GBF) was assessed by H(2)-gas clearance technique and plasma gastrin levels and the gastric mucosal generation of PGE2, superoxide dismutase (SOD) activity and malonyldialdehyde (MDA) concentration, as an index of lipid peroxidation were determined. RESULTS: Ethanol and WRS caused gastric lesions accompanied by the significant fall in the GBF and SOD activity and the rise in the mucosal MDA content. Pretreatment with GSE (8-64 mg/kg i g) dose-dependently attenuated gastric lesions induced by 100% ethanol and WRS; the dose reducing these lesions by 50% (ID(50)) was 25 and 36 mg/kg, respectively, and this protective effect was similar to that obtained with methyl PGE2 analog (5 μg/kg i g). GSE significantly raised the GBF, mucosal generation of PGE(2), SOD activity and plasma gastrin levels while attenuating MDA content. Inhibition of PGE(2) generation with indomethacin or rofecoxib and suppression of NO synthase by L-NNA or capsaicin denervation reversed the GSE-induced protection and the accompanying hyperemia. Co-treatment of exogenous calcitonine gene-related peptide (CGRP) with GSE restored the protection and accompanying hyperemic effects of GSE in rats with capsaicin denervation. CONCLUSION: GSE exerts a potent gastroprotective activity against ethanol and WRS-induced gastric lesions via an increase in endogenous PG generation, suppression of lipid peroxidation and hyperemia possibly mediated by NO and CGRP released from sensory nerves

Novel concept in the mechanism of injury and protection of gastric mucosa : role of renina-angiotensin system and active metabolites of angiotensin

The term cytoprotection pioneered by Robert and colleagues has been introduced to describe the remarkable ability of endogenous and exogenous prostaglandins (PGs) to prevent acute gastric hemorrhagic lesions induced by noxious stimuli such as ethanol, bile acids, hiperosmolar solutions and nonsteroidal anti-inflammatory agents such as aspirin. Since that time many factors were implicated to possess gastroprotective properties such as growth factors including epidermal growth factor (EGF) and transforming factor alpha (TGFα), vasodilatory mediators such as nitric oxide (NO) and calcitonin gene related peptide (CGRP) as well as appetite gut hormones including gastrin and cholecystokinin (CCK), leptin and recently ghrelin. This protective action of gut peptides has been attributed to the release of PG but question remains whether another peptide angiotensin, the classic component of the systemic and local renin-angiotensin system (RAS) could be involved in the mechanism of gastric integrity and gastroprotection. After renin stimulation, the circulating angiotensin I is converted to angiotensin II (ANG II) by the activity of the Angiotensin Converting Enzyme (ACE). The ANG II acting via its binding to two major receptor subtypes the ANG type 1 (AT1) and type 2 (AT2) has been shown be activated during stress and to contribute to the pathogenesis of cold stress- and ischemia-reperfusion-induced gastric lesions. All bioactive angiotensin peptides can be generated not only in systemic circulation, but also locally in several tissues and organs. Recently the new functional components of RAS, such as Ang-(1-7), Ang IV, Ang-(1-12) and novel pathways ACE2 have been described suggesting the gastroprotective role for the novel ANG II metabolite, Ang-(1-7). The fact that Ang-(1-7) is produced in excessive amounts in the gastric mucosa of rodents and that pretreatment by Ang-(1-7) exhibits a potent gastroprotective activity against the gastric lesions induced by cold-restraint stress suggests that this and possibly other vasoactive metabolites of ANG II pathway could be involved in the mechanism of gastric integrity and gastroprotection. This review summarizes the novel gastroprotective factors and mechanisms associated with metabolic fate of systemic and local RAS activation with major focus to recent advancement in the angiotensin pathways in the gut integrity

Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

The relation between nut consumption and cholesterol level in the urban population.

Cel pracy: Głównym celem pracy była ocena zależności pomiędzy częstością spożycia orzechów a poziomem cholesterolu całkowitego u kobiet i mężczyzn w wieku 45-69 lat w populacji wielkomiejskiej.Metoda: W analizie wykorzystano dane wtórne, zebrane w badaniu HAPIEE ( Health, Alcohol and Psychosocial factors In Estern Europe). Do pracy wykorzystano dane z I fazy (2002-2005) uzyskane z losowo wybranej grupy 1014 osób. Wyniki:Do dalszej analizy włączono osoby dla których były dane zarówno o stężeniu cholesterolu, jak i o spożyciu orzechów, czyli 881 osób. W badanej grupie częste spożycie orzechów (tj. 1/tydzień lub częściej) deklarowało blisko 12% osób. Częstość spożycia orzechów była istotnie wyższa u osób z nadwagą.Częstość spożycia orzechów nie była związana z płcią, wykształceniem i paleniem papierosów.W młodszej grupie wiekowej spożycie orzechów było częstsze niż w grupie starszej wiekowo. U kobiet wyższe spożycie orzechów było związane z niższym poziomem cholesterolu i rzadszym występowaniem hipercholesterolemii. U mężczyzn nie było istotnego związku pomiędzy spożyciem orzechów a poziomem cholesterolu i częstością hipercholesterolemii.Wnioski: Spożycie orzechów, które mają wiele korzystnych składników, nie było zbyt częste. Częste spożycie orzechów było związane z niższym poziomem cholesterolu całkowitego ale tylko u kobiet.The aim: The purpose of this study was to evaluate the dependence between the frequency of nut consumption and the level of total cholesterol present among women and men in the age range of 45 to 69 in the urban population.The method: During the analysis the data collected in the HAPIEE study (Health, Alcohol and Psychosocial factors In Eastern Europe) were used. In the research, the data used was from the I phase (2002-2005) obtained from a randomly selected group of 1014 people. The results: In the further research, there were taken into account only people with known data about both the concentration of cholesterol and the nut consumption. It was a number of 881 people. In that group of people nearly 12% of tested declared a frequent nut consumption (e.g. 1 per week or more). The frequency of nut consumption was higher among obese people. That frequency was not connected with sex, profession or smoking. Among the younger group of people it was not much higher. Among women, the higher consumption of nuts was related to lower cholesterol level and less frequent occurrence of hypercholesterolemia. Among men there was no connection between nut consumption and cholesterol level and the frequency of hypercholesterolemia occurrence. The conclusion: The consumption of nuts which have many important nutrients, was not that frequent. Repeated nut consumption was associated with lower levels of total cholesterol but only in case of women

Profilaktyka odleżyn w zakładach opiekuńczo-leczniczych

Odleżyny należą do trudno gojących się ran przewlekłych, stanowią poważny problem wielu oddziałów szpitalnych oraz jednostek sprawujących opiekę nad osobami obłożnie chorymi, w podeszłym wieku i długotrwale unieruchomionymi. Celem pracy było ukazanie profilaktyki przeciwodleżynowej, umiejętność oceny ryzyka powstawania odleżyn, utrzymanie prawidłowego stanu skóry poprzez właściwą pielęgnację, a także zapewnienie właściwego stanu odżywienia, aktywizacja chorego, kompleksowa i zindywidualizowana opieka oraz zastosowanie środków przeciwodleżynowych. Poważne konsekwencje rozwoju odleżyn oraz trudności w leczeniu powodują konieczność stworzenia zintegrowanego systemu profilaktyki i rejestracji odleżyn