Nesfatin-1 – More than a food intake regulatory peptide

Nesfatin-1 was discovered a decade ago and despite the fact that it represents just one of a multitude of food intake-inhibiting factors it received increasing attention. This led to a detailed characterization of NUCB2/nesfatin-1's physiological property to reduce food intake and also gave rise to an involvement in the long term regulation of body weight, especially under conditions of obesity. In addition, studies indicated the involvement of NUCB2/nesfatin-1 in other homeostatic functions as well: glucose homeostasis, water intake, gastrointestinal functions, temperature regulation, cardiovascular functions, puberty onset and sleep. These pleiotropic actions underline the physiological relevance of this peptide. Recently, the involvement of NUCB2/nesfatin-1 in psychiatric disorders such as anxiety has been investigated giving rise to the speculation that NUCB2/nesfatin-1 represents a peptidergic link between eating and anxiety/depression disorders.     

A biomechanical approach to the analysis of methods and procedures of bariatric surgery

Bariatric surgery includes a variety of procedures that are performed on obese people and aim at decreasing the intake of food and calories. This goal is usually pursued by reducing stomach capacity and/or absorbing capability. Adjustable gastric banding is the most common and successful operation. In general, bariatric surgical procedures are effective, but are often associated with major complications.Surgical procedure and post-surgical conformation of the stomach are usually defined on clinical and surgical basis only. Instead, the optimal configuration should be identified by analyzing the mechanical functionality of the stomach and the surrounding structures, and the relationship between food intake, nutrient adsorption, mechanical stimulation of stomach wall and feeling of satiety.A novel approach to bariatric surgery is required, integrating competences in the areas of biomechanics, physiology and surgery, based on a strong interaction between engineers and clinicians. Preliminary results from coupled experimental and computational investigations are here reported. The analyses aim to develop computational tools for the investigation of stomach mechanical functionality in pre- and post-surgical conformations.     

Distribution of lactobacilli in the porcine gastrointestinal tract

Abstract Characteristics of the lactobacilli colonizing the various regions of the porcine gastrointestinal tract were investigated. The lumenal contents from the gastric, jejunal, cecal and colonic regions, and biopsies from the gastric non-secreting and secreting regions were homogenized and serial dilutions were spread on Rogosa agar and colonies (50 per region and animal) were randomly sampled. The lactobacillus isolates were grouped according to their protein profiles of lysozyme-treated whole cells. Several different groups of lactobacillus could be detected. Specific groups were associated and often unique for the stomach, jejunal, cecal and colonic regions of the gastrointestinal tract. A few groups were uniformly distributed through the tract. Although published studies of lactobacilli colonizing stomach mucosa have been restricted mainly to the non-secreting region, significant levels were also detected on the secreting stomach tissue. Population densities ranged from 2 × 10⁴ to 2 × 10⁶ CFU per cm² on both the secretory and non-secretory regions. Of the isolates which colonized the gastric secreting epithelium, 26% formed smooth colonies and 74% formed rough colonies. In contrast, the non-secreting epithelium was mainly colonized by lactobacilli forming smooth colonies (67%). From this study, one can suggest that different lactobacilli are associated with specific regions of the gastrointestinal tract, and that some specific groups appear to be restricted to defined regions.     

Some effects of shark nets in the Natal nearshore environment

Synopsis Protective gillnets (shark nets) have been successful in reducing the frequency of shark attacks on the coast of Natal, South Africa. This is achieved primarily through a reduction in numbers of large sharks. The nets also take a by catch of dolphins, sea turtles, batoids and teleosts. Concern has been expressed over the direct effect of mortalities on the various stocks and also the broader, indirect effects on the inshore system. Catch rates of most shark species declined initially but have shown no trend since the mid-1970s. A first estimate of the reduction in total shark numbers is provided, and factors such as stock identity and net avoidance are discussed. Turtle and teleost stocks do not appear to be threatened by net mortalities but marine mammalogists are investigating the sustainability of catches of two dolphin species. Certain batoids may have declined despite a high release rate, but more data are needed. A published contention that shark netting has resulted in a proliferation of small sharks through reduced predation is re-examined and considered to be exaggerated. Reduced predation on dolphins, as a result of shark netting, is estimated.     

Chronic metformin intake and gastric cancer: A pooled analysis within the Stomach cancer Pooling (StoP) Project

IntroductionThe association between chronic use of metformin and risk of gastric cancer (GC) has been investigated with contradicting results. We aimed to study the association between chronic use of metformin and GC by using data from the Stomach cancer Pooling (StoP) Project, an epidemiological consortium of case-control studies on GC.MethodsData from three studies of the StoP Project with available information on metformin intake were analyzed.Multivariable logistic regression models were used to estimate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between chronic use of metformin and GC risk. Analyses were adjusted for sex, age, socioeconomic status, body mass index, smoking status, alcohol drinking status, and history of diabetes. Study-specific ORs and 95% CIs were then pooled with a random-effects model.The dose-response relationship between the duration of metformin intake and GC was assessed with a one-stage logistic model, and the duration of intake was modelled using second-order fractional polynomials.ResultsThe OR of GC in metformin users versus non-users was 1.01 (95% CI=0.61, 1.67). The association between metformin and GC did not change among different strata of study participants’ characteristics or when restricting the analyses to those with a history of diabetes.The dose-response analysis showed a slightly reducing trend in the OR of GC and a borderline significant association with increasing duration of metformin intake.ConclusionsThe results of our study do not clearly support an association between chronic use of metformin and GC, warranting further research.     

糖尿病大鼠ghrelin和nesfatin-1表达动力学及其调控

目的:探讨STZ诱导糖尿病大鼠ghrelin和nesfatin-1动力学及分泌调节变化。方法:STZ诱导糖尿病大鼠模型;采用葡糖糖脱氢酶分析法测量血浆葡萄糖水平;免疫放射分析检测血浆ghrelin、nesfatin-1、胰岛素、胰岛素样生长因子1(IGF-1)、生长激素(GH)含量;采用real-time PCR检测ghrelin m RNA水平变化;免疫组化观察ghrelin和nesfatin-1免疫活性细胞数量。结果:糖尿病大鼠体重显著降低(t=23.16,P<0.01),血糖水平显著升高(t=22.55,P<0.01),血浆胰岛素和IGF-1水平显著降低(t=6.50,t=24.13,P<0.01),但GH水平显著升高(t=3.30,P<0.05)。糖尿病大鼠血浆总ghrelin(t=7.03,P<0.01)和活性ghrelin(t=3.33,P<0.05)水平均显著升高,血浆nesfatin-1水平则显著降低(t=6.24,P<0.01);糖尿病大鼠血浆总ghrelin与GH(r=0.81,P<0.01)和IGF-1水平(r=-0.58,P<0.01)呈显著相关性;与对照组大鼠相比,糖尿病大鼠胃总ghrelin(t=16.86,P<0.01)和活性ghrelin(t=3.30,P<0.05)水平均显著降低;而胃nesfatin-1(t=7.93,P<0.01)水平则显著升高。胃总ghrelin水平与血浆IGF-1水平呈明显相关性(r=0.65,P<0.01);与对照组大鼠相比,糖尿病大鼠胃ghrelin m RNA表达水平显著升高(t=16.8,P<0.01),胃底ghrelin免疫活性细胞数量显著减少(t=3.98,P<0.01);实验中给予大鼠自由饮食,糖尿病大鼠血浆总ghrelin水平显著增加(t=7.53,P<0.01),nesfatin-1水平显著降低(t=5.46,P<0.01)。糖尿病大鼠注射胰岛素后,可使增加的ghrelin水平(t=1.76,P=0.11)和降低的nesfatin-1水平接近正常(t=1.96,P=0.06);且胰岛素可显著反转糖尿病大鼠胃总ghrelin(t=8.54,P<0.01)和nesfatin-1水平(t=2.42,P<0.05);以及注射胰岛素后,糖尿病大鼠胃底ghrelin细胞显著增加,nesfatin-1细胞明显减少(t=3.21,t=2.59,P<0.05)。结论:Ghrelin或nesfatin-1参与糖尿病大鼠能量平衡调控。     

凋亡相关基因Bcl-2、Bax及细胞色素C在糖尿病胃组织壁细胞中的表达

目的观察糖尿病大鼠胃组织中Bcl-2、Bax及细胞色素C表达变化。方法SD雄性大鼠腹腔注射链脲佐菌素(STZ)复制糖尿病动物模型,分别于4周、12周后测体重和血糖,胃内色素排空检测,光镜观察胃组织形态学变化,免疫组织化学观察Bcl-2、Bax及细胞色素C蛋白表达变化。结果糖尿病组大鼠胃内色素残留率显著增加,胃壁细胞胞质空泡改变。与正常对照组比较糖尿病组大鼠胃壁细胞Bax及细胞色素C表达随病程延长显著增加,而Bcl-2随病程延长表达减弱。结论Bcl-2、Bax及细胞色素C在糖尿病胃组织壁细胞中出现了一定的变化规律。引起壁细胞凋亡增加,导致胃粘膜功能异常,这可能是糖尿病胃瘫的重要发病机制之一。     

The diet of the badger Meles meles in the Republic of Ireland

The diet of the Eurasian badger (Meles meles) in the Republic of Ireland was studied by examination of the stomach contents of 686 badgers, collected between March 2005 and September 2006. It was found that the relative importance of different food types, as indicated by their frequency of occurrence and ingested bulk in the diet, fluctuated seasonally. Tipulid larvae (Cl. Insecta, Ord. Tipulidae) dominated the diet in spring; Anura (Cl. Amphibia) and Aculeata (Ord. Hymenoptera) during the summer; and Noctuid larvae (Cl. Insecta, Ord. Noctuidae) in autumn and winter. Thus this type of foraging behaviour supports the contention that badgers are generalist foragers with seasonal food preferences. This feeding behaviour is more similar to that of badgers in Italy and Spain than to badgers in England.     

建立胃癌实验动物模型方法的研究

目的通过对人低分化胃癌细胞系SGC-7901状态和接种细胞数目的研究,建立良好的皮下接种胃癌的动物模型。方法采用腹腔注射SGC-7901细胞,使裸鼠形成腹水;光镜及电镜观察细胞状态;将购买的SGC-7901细胞以及形成腹水后的肿瘤细胞分别以1×108、1×107和1×106个进行裸鼠皮下接种,每组接种5只。观察其肿瘤形成时间、大小、状态及病理学变化。结果SGC-7901细胞接种裸鼠形成腹水后进行培养的肿瘤细胞增殖状态发生改变;购买的SGC-7901细胞以1×108及1×107接种裸鼠,在第21天肿瘤组织中央均出现出血和坏死;1×106的裸鼠第21天未见肉眼可见的肿瘤形成。腹水培养的肿瘤细胞,接种1×108的裸鼠在第21天肿瘤组织中央可见大面积的出血和坏死;接种1×107及1×106的裸鼠在第21天均未见出血和坏死,接种1×107的肿瘤组织体积较大。结论SGC-7901细胞接种裸鼠形成腹水后的细胞,更容易建立SGC-7901细胞皮下接种的胃癌动物模型,其中以接种细胞数为1×107的肿瘤生长较好,更适用于胃癌的实验研究。     

局部进展期胃癌术前动静脉结合化疗的疗效观察

目的:局部进展期胃癌,即使没有出现远处转移或腹膜种植,预后也极不理想.我们对局部进展期胃癌患者进行术前mECF方案的动静脉结合化疗,以评价其治疗疗效.方法:选取自2009年1月至2011年6月间我院局部进展期胃癌Ⅱ-ⅢC期患者38例,均由影像学确定淋巴结高度可疑转移或浸润、包绕主要血管结构,且没有发现远处转移或腹膜种植,进行2个周期的术前动静脉结合化疗后,行手术治疗.记录化疗毒性反应、临床、病理缓解率、手术并发症发生率和病死率以及1年无病生存率.结果:化疗毒性反应低,3级反应不超过10％,仅有1例出现4级反应,表现为腹泻、恶心和呕吐.38例患者中临床CR有6例,占15.8％,PR17例,占44.7％,NC13例(34.2％),PD2例(5.3％),RR为60.5％(23/38).全部患者均施行了手术,37例患者进行了根治性手术,R0切除率为97％.病理缓解率为5例完全缓解(13.2％),21例部分缓解(55.3％),8例轻微缓解(21.1％),4例未缓解(10.5％).手术并发症发生率为7.9％,无治疗相关死亡发生.1年无病生存率为81.6％.结论:局部进展期胃癌患者术前进行mECF方案的动静脉化疗毒性反应低,疗效理想,之后行手术完整切除后临床效果突出,是理想的治疗方法.