Enzymatic synthesis and surface active properties of novel hemifluorinated mannose esters

The lipase-catalysed esterification of sugars with hemifluorinated acid derivatives is reported for the first time. A series of mannose modified derivatives having fluorinated chains with different length have been prepared accordingly in moderate yield. A preliminary evaluation of the surface active properties of these hemifluorinated mannose esters revealed their ability to reduce the surface tension of water much more efficiently than their aliphatic counterparts.     

Community analysis of bacteria colonizing intestinal tissue of neonates with necrotizing enterocolitis

Background  

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in newborn neonates. Bacteria are believed to be important in the pathogenesis of NEC but bacterial characterization has only been done on human faecal samples and experimental animal studies. The aim of this study was to investigate the microbial composition and the relative number of bacteria in inflamed intestinal tissue surgically removed from neonates diagnosed with NEC (n = 24). The bacterial populations in the specimens were characterized by laser capture microdissection and subsequent sequencing combined with fluorescent in situ hybridization (FISH), using bacterial rRNA-targeting oligonucleotide probes.     

Mobilisation of hematopoietic CD34+ precursor cells in patients with acute stroke is safe--results of an open-labeled non randomized phase I/II trial

Background

Regenerative strategies in the treatment of acute stroke may have great potential. Hematopoietic growth factors mobilize hematopoietic stem cells and may convey neuroprotective effects. We examined the safety, potential functional and structural changes, and CD34⁺ cell–mobilization characteristics of G-CSF treatment in patients with acute ischemic stroke.

Methods and Results

Three cohorts of patients (8, 6, and 6 patients per cohort) were treated subcutaneously with 2.5, 5, or 10 µg/kg body weight rhG-CSF for 5 consecutive days within 12 hrs of onset of acute stroke. Standard treatment included IV thrombolysis. Safety monitoring consisted of obtaining standardized clinical assessment scores, monitoring of CD34⁺ stem cells, blood chemistry, serial neuroradiology, and neuropsychology. Voxel-guided morphometry (VGM) enabled an assessment of changes in the patients'' structural parenchyma. 20 patients (mean age 55 yrs) were enrolled in this study, 5 of whom received routine thrombolytic therapy with r-tPA. G-CSF treatment was discontinued in 4 patients because of unrelated adverse events. Mobilization of CD34⁺ cells was observed with no concomitant changes in blood chemistry, except for an increase in the leukocyte count up to 75,500/µl. Neuroradiological and neuropsychological follow-up studies did not disclose any specific G-CSF toxicity. VGM findings indicated substantial atrophy of related hemispheres, a substantial increase in the CSF space, and a localized increase in parenchyma within the ischemic area in 2 patients.

Conclusions

We demonstrate a good safety profile for daily administration of G-CSF when begun within 12 hours after onset of ischemic stroke and, in part in combination with routine IV thrombolysis. Additional analyses using VGM and a battery of neuropsychological tests indicated a positive functional and potentially structural effect of G-CSF treatment in some of our patients.

Trial Registration

German Clinical Trial Register DRKS 00000723     

Temperature effects on growing, feeding, and swimming energetics in the Patagonian blennie Eleginops maclovinus (Pisces: Perciformes)

The Patagonian blennie Eleginops maclovinus is a coastal and estuarine species, important in recreational and commercial fisheries, and with aquaculture potential. This study assessed the effect of temperature on feeding and the allocation of energy in growth and swimming in a sub-Antarctic population. For growth experiments, two groups of 8 juveniles were reared at 4 and 10?°C (corresponding to winter and summer habitat temperatures, respectively) for 3?months. Swimming experiments were conducted at 5 and 10?°C, measuring the oxygen consumption before and after forced swimming for 1?min at a speed of 10 total lengths (TL)/s. Temperature affects growth. TL increased 0.09?cm at 4?°C versus 0.30?cm at 10?°C. Body mass grew 0.49?g at 4?°C versus 1.65?g at 10?°C, whereas the Fulton’s condition factor increased 0.021 at 4?°C versus 0.080 at 10?°C. The ingested food was more than twofold higher at 10 than at 4?°C, while the feces produced at 4?°C was about twofold higher. The scope between baseline and peak oxygen consumption after forced swimming was affected by temperature, being 4.51 at 5?°C and 3.03 at 10?°C. The percentage energy expenditure until the return of baseline oxygen consumption values showed a marked temperature effect, being higher at 5?°C. We propose the existence of a trade-off in the allocation of energy between swimming activity and growth, with proportionally more energy being consumed at low temperatures for swimming than for other physiological functions like growth.     

谷氨酸棒杆菌anti-σ因子CseE及其突变体与σ因子SigE的相互作用分析

[目的]谷氨酸棒杆菌是重要的氨基酸生产菌株,本研究针对SigE与ZAS家族蛋白CseE相互作用机制进行探索研究,重点分析CseE突变体影响与SigE结合能力的机制。[方法]本研究选择谷氨酸棒杆菌ATCC 13032来源的SigE和CseE蛋白为研究目标,利用遗传学方法获得过表达的重组谷氨酸棒杆菌,通过RT-qPCR研究SigE调控sigE和cseE的转录情况。同时,利用ITC和His pull-down实验验证ZAS家族的CseE蛋白与Zn²⁺及SigE的结合情况。之后对CseE蛋白进行功能域分析、多序列比对,研究功能域关键氨基酸位点对SigE结合能力的影响。其次对SigE和CseE蛋白进行分子对接和动力学模拟,分析关键氨基酸影响其结合的机制。[结果]谷氨酸棒杆菌SigE调控基因sigE和cseE的转录并且其活性受CseE蛋白控制。CseE蛋白为ZAS家族蛋白,具有Zn²⁺结合能力。CseE_His83A、CseE_cys87A和CseE_cys90A突变体不会影响与SigE的结合能力,而CseE_C87A-C90A和CseE_{His83A-C87A-C90A}突变体与SigE的结合能力略有下降。分子动力学模拟发现SigE-CseE_C87A-C90A和SigE-CseE_{His83A-C87A-C90A}之间的结合能量为-17.23 kcal/mol和-14.06 kcal/mol,分别比未突变体系结合能量降低22.8%及36.9%。[结论]谷氨酸棒杆菌SigE通过聚集RNA聚合酶来调控基因sigE和cseE的表达。CseE蛋白属于ZAS家族,具有Zn²⁺结合能力同时通过与SigE蛋白互作来抑制SigE活性。CseE_C87A-C90A及CseE_{His83A-C87A-C90A}突变体能影响与SigE结合的能力,减弱对SigE活性的控制。本研究产生的三维结构和确定的氨基酸关键位点为后续探索谷氨酸棒杆菌SigE和CseE响应环境压力机制提供了理论基础。     

Cassava Intake and Vitamin A Status among Women and Preschool Children in Akwa-Ibom,Nigeria

Background

As part of the HarvestPlus provitamin A-biofortified cassava program in Nigeria we conducted a survey to determine the cassava intake and prevalence of vitamin A deficiency among children 6-59 months and women of childbearing age in the state of Akwa Ibom.

Methods

A cluster-randomized cross-sectional survey was conducted in 2011 in Akwa Ibom, Nigeria. The usual food and nutrient intakes were estimated using a multi-pass 24-hour recall with repeated recall on a subsample. Blood samples of children and women were collected to analyze for serum retinol, serum ferritin, and acute phase proteins as indicators of infection. Vitamin A deficiency was defined as serum retinol <0.70 μmol/L adjusted for infection.

Results

A total of 587 households of a mother-child dyad participated in the dietary intake assessment. Cassava was very widely consumed in Akwa Ibom, mainly as gari or foofoo. Daily cassava consumption frequency was 92% and 95% among children and women, respectively. Mean (±SD) cassava intake (expressed as raw fresh weight) was 348 ± 317 grams/day among children and 940 ± 777 grams/day among women. Intakes of most micronutrients appeared to be adequate with the exception of calcium. Median vitamin A intake was very high both for children (1038 μg RAE/day) and women (2441 μg RAE/day). Red palm oil and dark green leafy vegetables were the main sources of vitamin A in the diet, with red palm oil alone contributing almost 60% of vitamin A intake in women and children. Prevalence of vitamin A deficiency ranged from moderate (16.9 %) among children to virtually non-existent (3.4 %) among women.

Conclusion

Consumption of cassava and vitamin A intake was high among women and children in Akwa Ibom with a prevalence of vitamin A deficiency ranging from moderate in children to non-existent among women. The provitamin A biofortified cassava and other vitamin A interventions should focus dissemination in states where red palm oil is not widely consumed.     

Absorption spectra of photoactive yellow protein chromophores in vacuum

The absorption spectra of two photoactive yellow protein model chromophores have been measured in vacuum using an electrostatic ion storage ring. The absorption spectrum of the isolated chromophore is an important reference for deducing the influence of the protein environment on the electronic energy levels of the chromophore and separating the intrinsic properties of the chromophore from properties induced by the protein environment. In vacuum the deprotonated trans-thiophenyl-p-coumarate model chromophore has an absorption maximum at 460 nm, whereas the photoactive yellow protein absorbs maximally at 446 nm. The protein environment thus only slightly blue-shifts the absorption. In contrast, the absorption of the model chromophore in aqueous solution is significantly blue-shifted (lambda(max) = 395 nm). A deprotonated trans-p-coumaric acid has also been studied to elucidate the effect of thioester formation and phenol deprotonation. The sum of these two changes on the chromophore induces a red shift both in vacuum and in aqueous solution.     

西瓜食酸菌Ⅲ型效应蛋白AopAI的鉴定及其功能初步分析

【背景】西瓜食酸菌（Acidovorax citrulli,Ac）引起的细菌性果斑病是葫芦科植物重要的病害之一,通过Ⅲ型分泌系统（type Ⅲ secreted system,T3SS）分泌至植物体内的Ⅲ型效应蛋白（type Ⅲ effector,T3E）是该菌重要的致病因子,目前对Ac T3E的认识仍然非常有限。【目的】鉴定西瓜食酸菌候选的T3E Acidovorax outer protein AI （AopAI）,分析其对Ac致病力的影响和干扰植物免疫的方式。【方法】利用生物信息学方法分析AopAI序列特征、AvrBs1无毒报告系统验证蛋白转运功能;通过荧光定量PCR技术分析aopAI基因表达的调控及其对植物病原相关分子模式（pathogen-associated molecular pattern,PAMP）激发的免疫反应（PAMP-triggered immunity,PTI）信号通路标记基因表达的影响;利用基因插入突变和基因功能互补方法,检测菌的致病力、植物组织过氧化氢和胼胝质积累量的变化;运用瞬时表达技术分析AopAI亚细胞定位和其抑制激发子诱导细胞死亡的能力。【结果】AopAI蛋白序列中不含跨膜螺旋区和信号肽,含有二磷酸腺苷（adenosine diphosphate,ADP）核糖基转移酶保守结构域;在T3SS核心基因hrpG和hrpX突变体中aopAI基因表达量显著降低;表达AopAI及AvrBs1功能区（59-445 aa）的avrBs1突变体可诱导ECW-10R辣椒叶发生过敏性坏死反应,表明AopAI具有转运功能;aopAI基因突变体在黄瓜子叶上的致病力减弱,但与其互作的黄瓜子叶组织中过氧化氢和胼胝质的含量均显著增加;AopAI在本氏烟叶瞬时表达后,显示其定位于细胞膜和细胞核,还表现抑制激发子NIP诱导的叶细胞死亡,导致叶细胞的PTI信号通路标记基因GRAS2和ACRE31的表达量显著降低。【结论】在西瓜食酸菌中具有一个定位于细胞核和细胞膜、有ADP核糖基转移酶结构域的T3E蛋白AopAI,该T3E是能够抑制NIP诱导的细胞死亡的毒性蛋白,通过抑制ACRE31调节的免疫途径降低植物过氧化氢和胼胝质的积累,以抑制植物PTI防御反应机制。     

Response of soil organic carbon to land-use change in central Brazil: a large-scale comparison of Ferralsols and Acrisols

Plant and Soil - The southeastern part of the Amazon region is one of the largest agricultural frontiers in the world, leading to extensive land-use change. This paper provides evidence for the...