Zonation and seasonality of benthic primary production and community respiration in tropical mangrove forests

Benthic oxygen consumption and primary production were measured using the bell jar technique in deltaic and fringing mangrove forests of tropical northeastern Australia. In a deltaic forest, rates of sediment respiration ranged from 197 to 1645 mol O₂ m^–2 h^–1 (mean=836), but did not vary significantly with season or intertidal zone. Gross primary production varied among intertidal zones and seasons, ranging from –281 to 1413 mol O₂ m^–2 h^–1 (mean=258). Upon tidal exposure, rates of gross primary production increased, but respiration rates did not change significantly. In a fringing mangrove forest, benthic respiration and gross primary production exhibited strong seasonality. In both forests, rates of oxygen consumption and production were low compared to salt marshes, but equivalent to rates in other mangrove forests. The production:respiration (P/R) ratio varied greatly over space and time (range:–0.61 to 1.76), but most values were «1 with a mean of 0.15, indicating net heterotrophy. On a bare creek bank and a sandflat, rates of gross primary production and P/R ratios were generally higher than in the adjacent mangroves. Low microalgal standing stocks, low light intensity under the canopy, and differences in gross primary production between mangroves and tidal flats, and with tidal status, indicate that benthic microalgae are light-limited and a minor contributor to primary productivity in these tropical mangrove forests.     

In vivo evidence of role of bone morphogenetic protein-4 in the mouse ovary

The transition of a primordial follicle to a primary follicle is an early step in folliculogenesis. All female mammals are born with a fixed stock of primordial follicles, and exhaustion of that stock leads to menopause or infertility. Recently, several in vitro studies have indicated that BMP-4, BMP-7, and several other growth factors affect the transition of primordial to primary follicles. The aim of our present study was to investigate role of BMP-4 in this process using passive immunization to investigate the role of BMP-4 in a prepubertal mouse model. After seven days of treatment, the weight of antiBMP-4 treated ovaries was significantly lower than the ovaries from mice treated with nonimmune Ig. The number of primary follicles was lower, and the numbers of primordial follicles were higher in antiBMP-4 treated ovaries compared to control ovaries. Treatment with equine chorionic gonadotrophin (eCG) showed no influence on the effects of antiBMP-4 in the mouse ovary. Thus, the results of our study indicate that in vivo BMP-4 acts as transition factor in transition of primordial to primary follicle.     

Expression of Trisk 51, agrin and nicotinic-acetycholine receptor ε-subunit during muscle development in a novel three-dimensional muscle-neuronal co-culture system

The purpose of our study was to create functional muscle tissue in vitro and to investigate the influence of organotypic neuronal slice cultures from rat spinal cord on the differentiation and function of primary rat myoblasts in a novel three-dimensional culture system. Three-dimensional muscle-neuronal cultures were established by co-cultivating primary rat skeletal muscle cells of newborn rats with organotypic slice cultures of the spinal cord prepared from isogenic rats in a fibrin matrix. These constructs were cultured for up to 4 weeks. Differentiation and fusion of the myoblasts to myofibers was evaluated by analyzing the expression pattern and localization of muscle- and neuron-specific markers. The fibrin matrix provided a suitable environment for three-dimensional myoblast culture. Co-culturing of organotypic spinal cord slices with myoblasts induced the formation of spontaneously contracting multinuclear and parallel-aligned myofibers. Pharmacological tests suggested the formation of neuromuscular junctions. The analysis of neural agrin expression and myogenic desmin, myogenin, MyoD, Trisk 51, and nicotinic-acetycholine receptor (nACh-receptor) -subunit expression revealed the differentiation of the myoblasts to myofibers. The presented novel three-dimensional co-culture system allows the in vitro investigation of myoblast differentiation and neuron-myoblast interaction. Our results suggest the existence of an alternative pathway for the maturation of the nAChR -subunit to the -subunit without neural agrin activity.A.D.B. and J.P.B. contributed equally to this studyThis work was supported by a major grant from the State of Baden-Württemberg within the scope of the Valley TEC (Valley Tissue Engineering Center)     

原发性肝癌患者术后两种营养支持的疗效对比及对免疫功能的影响研究

目的:研究原发性肝癌患者术后两种营养支持的疗效及对免疫功能的影响。方法:病例选自2010年10月至2012年11月在我院就诊治疗的90例经诊断为原发性肝癌并进行肝部分切除的患者,随机分为EN组和PN组,每组各45例,分别进行肠内和肠外营养支持治疗,观察术前及术后患者的营养状况、住院时间、肠道功能恢复时间、并发症情况及免疫功能的变化,经统计学处理,探讨两种不同营养支持疗法的临床疗效及对免疫功能的影响。结果:相对于PN组,EN组患者术后营养明显改善,胃肠道功能恢复相对较快,免疫功能明显提高,术后并发症明显减少,且P0.05。差异具有统计学意义。结论:早期EN比PN更能改善肝癌病人术后肠道功能及营养状况,降低术后并发症,提高患者的免疫功能,有利于患者术后恢复。     

原代小鼠肝脏细胞的高效分离纯化与培养

目的：建立一种能稳定获得高活力和高纯度原代小鼠肝脏细胞的分离、纯化及培养方法。方法：应用改良的Seglen 二步法原位灌注和机械离心分离肝脏细胞,并用改良的高糖DMEM培养基进行培养。台盼蓝拒染法检测接种时肝脏细胞的存活率,倒置显微镜动态观察肝脏细胞形态变化,应用免疫荧光技术对肝脏细胞进行Albumin 染色。结果：每只小鼠可获取肝脏细胞的总产量平均为1.35× 10^6 / g体重,肝脏细胞存活率＞ 90%。倒置显微镜下观察贴壁前肝细胞直径为35.14 滋m± 4.35 滋m,肝脏细胞在接种后3 h基本完成贴壁;肝脏细胞接种后24h,所有肝脏细胞均强阳性表达成熟肝脏细胞标志物Albumin,肝细胞纯度＞ 95%。结论：改良的分离纯化及培养方法能稳定获得高产量、高活率及高纯度的小鼠肝脏细胞。     

Hormonal concentrations in bitches with primary uterine inertia

Normal labor is accompanied by sequential changes in blood concentrations of prostaglandin F2α (measured as 15-ketodihydro-PGF2α = PGFM), progesterone, estradiol, oxytocin, vasopressin, and of elevated cortisol levels. The aim of this study was to investigate hormone concentrations in dogs diagnosed with primary uterine inertia before and during treatment by cesarian section. The hypothesis was the dogs would have abnormally low plasma concentrations in one or several of the hormones involved in parturition. The study comprised seven bitches with total primary uterine inertia (dystocia group) treated with cesarian section and six healthy bitches (control group) subjected to planned cesarean section. Blood samples were taken before anesthesia, before surgery started, on delivery of the first puppy and on delivery of the last puppy. The progesterone:PGFM ratio in plasma was higher in the dystocia group than in the control group, but the serum estradiol concentration did not differ between groups. The plasma concentrations of oxytocin and vasopressin increased in both groups when the first puppies were delivered, but both hormones were more elevated in the control group than in the dystocia group on delivery of the last puppies. The plasma cortisol concentration increased to the same level in both groups. In conclusion, the ratio between progesterone and PGFM was higher and the oxytocin and vasopressin concentrations lower in the dystocia dogs than in the control dogs. The findings indicate that these hormones are involved in the pathophysiology of total primary uterine inertia in bitches.     

B-type natriuretic peptide predicts new-onset atrial fibrillation in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention

The predictive value of B-type natriuretic peptide (BNP) with respect to the occurrence of new-onset atrial fibrillation (AF) in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PCI) is unknown. The aim of this study was to evaluate whether BNP has a predictive value for the occurrence of new-onset AF in patients with STEMI treated by primary PCI. In 180 patients with STEMI treated by primary PCI, BNP concentrations were measured 24h after chest pain onset. The Receiver Operating Characteristic analysis was performed to identify the most useful BNP cut-off level for the prediction of AF. The patients were divided into the two groups according to calculated cut-off level: high BNP group (BNP≥720 pg/mL, n=33) and low BNP group (BNP<720 pg/mL, n=147). The incidence of AF was 5.0%, and occurred more frequently in high BNP group (7/33, 21.2%) than in low BNP group (2/147, 1.4%), (p<0.001). Patients with high BNP were older (p=0.017), had more often anterior wall infarction (p=0.015), higher Killip class on admission (p=0.038), higher peak troponin I (p=0.002), lower left ventricular ejection fraction (p=0.029) than patients with low BNP. After multivariate adjustment, BNP was an independent predictor of AF (OR 3.70, 95% CI 1.40-9.77, p=0.008). BNP independently predicts the occurrence of new-onset AF in STEMI patients treated by primary PCI.     

2008～2009年青岛地区手足口病病原学的调查分析

本研究对2008～2009年青岛地区手足口病的病原学进行调查研究。首先对HFMD病例的咽拭子标本直接进行病毒核酸的提取,然后采用多重荧光逆转录-聚合酶链反应(RT-PCR)方法对总肠道病毒(Enterovirus,EV)、肠道病毒71型(Enterovirus Type 71,EV71)和柯萨奇病毒A组16型(Coxsackievirus Group A 16,CVA16)进行检测,对EV阳性而EV71和CVA16均阴性的标本采用半巢式反转录PCR进行肠道病毒VP1基因部分序列的扩增和序列分析以鉴定其血清型别。结果提示2008～2009年青岛地区手足口病的主要病原为EV71和CVA16,无论轻症和重症病例,EV71的比例都大于CVA16。2008年共获得5个(8株)其它血清型,分别是柯萨奇病毒(Cox-sackievirus,CV)的A5、A6、A10、A12及埃可病毒9(Echovirus 9,E9),血清型分布比较分散、均匀。2009年共获得3个其它血清型(13株),分别是CVA9、CVA12及CVB2,CVA12所占比例较大(11/13),分布比较集中。CVA12成为2009年青岛地区HFMD病原中除EV71和CVA16外,新的较为流行的病原。     

Large eddy simulation of the unsteady flow-field in an idealized human mouth-throat configuration

The present study concerns the simulation and analysis of the flow field in the upper human respiratory system in order to gain an improved understanding of the complex flow field with respect to the process affecting drug delivery for medical treatment of the human air system. For this purpose, large eddy simulation (LES) is chosen because of its powerful performance in the transitional range of laminar and turbulent flow fields. The average gas velocity in a constricted tube is compared with experimental data (Ahmed and Giddens, 1983) and numerical data from Reynolds-averaged Navier-Stokes (RANS) equations coupled with low Reynolds number (LRN) κ-ω model (Zhang and Kleinstreuer, 2003) and LRN shear-stress transport κ-ω model (Jayaraju et al., 2007), for model validation. The present study emphasizes on the instantaneous flow field, where the simulations capture different scales of secondary vortices in different flow zones including recirculation zones, the laryngeal jet zone, the mixing zone, and the wall shear layer. It is observed that the laryngeal jet tail breaks up, and the unsteady motion of laryngeal jet is coupled with the unsteady distribution of secondary vortices in the jet boundary. The present results show that it is essential to study the unsteady flow field since it strongly affects the particle flow in the human upper respiratory system associated with drug delivery for medical treatment.