Neutrophil extracellular trap cell death requires both autophagy and superoxide generation

Neutrophil extracellular traps (NETs) are extracellular chromatin structures that can trap and degrade microbes. They arise from neutrophils that have activated a cell death program called NET cell death, or NETosis. Activation of NETosis has been shown to involve NADPH oxidase activity, disintegration of the nuclear envelope and most granule membranes, decondensation of nuclear chromatin and formation of NETs. We report that in phorbol myristate acetate (PMA)-stimulated neutrophils, intracellular chromatin decondensation and NET formation follow autophagy and superoxide production, both of which are required to mediate PMA-induced NETosis and occur independently of each other. Neutrophils from patients with chronic granulomatous disease, which lack NADPH oxidase activity, still exhibit PMA-induced autophagy. Conversely, PMA-induced NADPH oxidase activity is not affected by pharmacological inhibition of autophagy. Interestingly, inhibition of either autophagy or NADPH oxidase prevents intracellular chromatin decondensation, which is essential for NETosis and NET formation, and results in cell death characterized by hallmarks of apoptosis. These results indicate that apoptosis might function as a backup program for NETosis when autophagy or NADPH oxidase activity is prevented.     

Research progress on monitoring vegetation water content by using hyperspectral remote sensing

植被含水量是陆地植被重要的生物物理特征, 其定量遥感反演有助于植被干旱胁迫的实时监测与诊断评估。该文系统综述了国内外利用高光谱遥感评估植被水分状况的4个常见植被水分指标——冠层含水量、叶片等量水厚度、活体可燃物湿度和相对含水量的概念及其遥感估算方法研究进展, 评述了植被含水量高光谱遥感估算各类方法的优缺点, 探讨了植被含水量高光谱遥感估算目前存在的问题, 并提出进一步的研究任务, 即服务于植被干旱胁迫的高光谱遥感监测、预警与评估。     

Live imaging of GLUT2 glucose-dependent trafficking and its inhibition in polarized epithelial cysts

GLUT2 is a facilitative glucose transporter, expressed in polarized epithelial cells of the liver, intestine, kidney and pancreas, where it plays a critical role in glucose homeostasis. Together with SGLT1/2, it mediates glucose absorption in metabolic epithelial tissues, where it can be translocated apically upon high glucose exposure. To track the subcellular localization and dynamics of GLUT2, we created an mCherry–hGLUT2 fusion protein and expressed it in multicellular kidney cysts, a major site of glucose reabsorption. Live imaging of GLUT2 enabled us to avoid the artefactual localization of GLUT2 in fixed cells and to confirm the apical GLUT2 model. Live cell imaging showed a rapid 15 ± 3 min PKC-dependent basal-to-apical translocation of GLUT2 in response to glucose stimulation and a fourfold slower basolateral translocation under starvation. These results mark the physiological importance of responding quickly to rising glucose levels. Importantly, we show that phloretin, an apple polyphenol, inhibits GLUT2 translocation in both directions, suggesting that it exerts its effect by PKC inhibition. Subcellular localization studies demonstrated that GLUT2 is endocytosed through a caveolae-dependent mechanism, and that it is at least partly recovered in Rab11A-positive recycling endosome. Our work illuminates GLUT2 dynamics, providing a platform for drug development for diabetes and hyperglycaemia.     

Resource use efficiency in urban and peri-urban sheep, goat and cattle enterprises

Urban livestock husbandry receives growing attention given the increasing urban demand for livestock products. At the same time, little is known about the resource use efficiency in urban livestock enterprises and eventual negative externalities. In livestock production, feeds are an important resource whose nutrients are transformed into products (meat and milk) to generate financial return to the producer. The lack of knowledge on nutrient supply through feed might lead to oversupply with severe environmental impacts. In Niamey, a typical West African city and capital of the Republic of Niger, urban livestock production is constrained by feed scarcity, especially during the dry season. Here, the issue of resource use efficiency was studied in 13 representative and differently managed sheep/goat and cattle enterprises characterized by high and low feed inputs, respectively, during a period of 28 months. Nitrogen (N), phosphorus (P) and potassium (K) inflows into each farm through livestock feeds and outflows through manure were determined using a semi-structured questionnaire; interviews were accompanied by regular weighing of feed supplied and dung produced. Live weight gain (LWG) and efficiency of conversion of total feed dry matter offered (kg TDMO/kg LWG) were computed along with nutrient balances (NBs) per metabolic body mass (kg0.75). NBs (per kg0.75/day) in the high-input (HI) sheep/goat enterprises were +1762.4 mg N, +127.2 mg P and +1363.5 mg K and were significantly greater (P < 0.05) than those in low-input (LI) units (+69.1 mg N, -98.3 mg P and +16.5 mg K). In HI cattle enterprises, daily balances averaged +454.1 mg N, +40.1 mg P and +341.8 mg K compared to +34.4 mg N, -9.0 mg P and +68.3 mg K (P > 0.05) in LI cattle systems. All systems were characterized by poor conversion efficiencies of offered feed, which ranged from 13.5 to 46.1 kg TDMO/kg LWG in cattle and from 15.7 to 43.4 kg TDMO/kg LWG in sheep/goats. LWG in HI sheep/goats was 53 g/day in the rainy season, 86 g/day in the hot dry season and 104 g/day in the cool dry season, while HI cattle lost 79 g/day in the hot dry season and gained 121 g/day and 92 g/day in the cool dry and rainy seasons, respectively. The data indicate that there is nutrient wasting and scope for improvement of feeding strategies in Niamey's livestock enterprises, which might also decrease nutrient losses to the urban environment.     

Universal Trap Timer Design to Examine Temporal Activity of Wildlife

Abstract: We designed a reliable and inexpensive universal trap timer that records the time from the moment a single-live-capture trap is triggered by an animal to when the observer checks the trap. Combined with trapping information, the diel activity pattern of a given species or demographic group can then be described or compared between imposed treatments. The universal trap timer is adaptable to operate reliably with most single-capture trap designs, requires no permanent modification of traps, and is easy to construct.     

Diatrack particle tracking software: Review of applications and performance evaluation

Object tracking is an instrumental tool supporting studies of cellular trafficking. There are three challenges in object tracking: the identification of targets; the precise determination of their position and boundaries; and the assembly of correct trajectories. This last challenge is particularly relevant when dealing with densely populated images with low signal‐to‐noise ratios—conditions that are often encountered in applications such as organelle tracking, virus particle tracking or single‐molecule imaging. We have developed a set of methods that can handle a wide variety of signal complexities. They are compiled into a free software package called Diatrack. Here we review its main features and utility in a range of applications, providing a survey of the dynamic imaging field together with recommendations for effective use. The performance of our framework is shown to compare favorably to a wide selection of custom‐developed algorithms, whether in terms of localization precision, processing speed or correctness of tracks.      

双歧杆菌四联活菌片联合乳果糖对儿童功能性便秘患者排便频次及肠道菌群的影响

使用双歧杆菌四联活菌片联合乳果糖的治疗方案对儿童功能性便秘患者排便频次及肠道菌群的影响进行探究。

通过随机数表法将选取的150例于2021年5月至2022年12月来我院进行便秘治疗的儿童分为观察组（75例）和对照组（75例）,对照组患儿采用乳果糖进行治疗,观察组在对照组乳果糖治疗的基础上给予双歧杆菌四联活菌片,对两组患儿的临床疗效、排便频次、肠道菌群和不良反应以及复发率作对比。

观察组和对照组患儿经治疗后的临床总有效率对比,对照组（86.67%）显著低于观察组（97.33%）,差异有统计学意义（χ² = 4.438,P = 0.035）;治疗后两组患儿便秘频次和便秘困难程度评分与治疗前相比均有所降低,且对照组患儿的便秘频次和便秘困难程度评分降低幅度不及观察组显著（t = 8.880,P＜0.001）;两组患儿经治疗后双歧杆菌数量均有增多,葡萄球菌、酵母菌、肠杆菌数量均有减少,且对照组患儿无论是双歧杆菌数量的增多情况或是葡萄球菌、酵母菌、肠杆菌数量的减少情况均不及观察组显著（t = 7.823,P＜0.001）;观察组和对照组患儿中的不良反应发生率分别为9.33%和12.00%,差异无统计学意义（χ² = 0.280,P = 0.597）,复发率在观察组和对照组患儿中分别为2.67%和14.67%,差异有统计学意义（χ² = 5.390,P = 0.020）。

双歧杆菌四联活菌片联合乳果糖能够有效改善患儿的临床症状,增加患儿排便频次,平衡肠道菌群,提高患儿的生活质量。

     

Immunological dynamics in response to two anthrax vaccines in mice

In order to understand the variation of humoral and cellular immune responses to A16R live spore and AVA vaccine and to identify efficient immunological parameters for the early evaluation of post immu- nization in mice, we dynamically monitored the antibody production and cellular responses after the vaccination of Balb/C mice with the anthrax vaccines. The results show that both anti-AVA and anti-Spore antibodies were detectable in the A16R live spore vaccinated group while high titers of anti-AVA antibodies but not anti-Spore antibodies existed in the AVA-immunized group. IgG1 and IgG2 were the major subtypes of IgG in both of the two groups. However, the IgG2a level was significantly higher in the A16R group than in the AVA group. At the cellular level, responses of antigen-specific TH2, TH1 and plasma cells were detected. The peripheral TH2 responses could be seen on day 5 after vac- cination, and remained at a high level throughout the experiment (from day 5 post primary immuniza- tion to day 60 post the tertiary immunization); the TH1 responses to A16R vaccine appeared on day 5, while the responses to AVA could only be detected by day 7 after the secondary immunization; a low level of TH1 responses could be observed at the end of the experiment. Antigen-specific plasma cells could be found in the peripheral blood of both the immunized groups, however, the responses in the A16R group appeared earlier, lasted longer, and shown an ascending tendency until the end of the ex- periment when the plasma cell responses in the AVA group were reduced to a very low level. The re- sults suggest that the multiple antigen containing A16R live spore vaccine induces better immune re- sponses than AVA. Combined with serum antibody titers, TH2, TH1 and plasma cell responses could be used as immunological parameters for the evaluation of vaccine efficacy. These findings may afford new insight into the early evaluation of vaccination as well as being a powerful strategy for vaccine development.     

两种不同保护剂冻干的仔猪副伤寒活疫苗质量比较

【目的】系统比较两种不同保护剂冻干的仔猪副伤寒活疫苗(耐热苗和常规苗)质量指标,为科学评价两种疫苗质量提供参考。【方法】制备耐热苗和常规苗各3批,分别进行物理性状、纯粹性、活菌计数、安全性、剩余水分、真空度和保存期等参数测定和比较,同时比较冻干前后的活菌存活率及耐老化性能。任选耐热苗与常规苗1批,按3×109 CFU分别口服与肌肉注射仔猪各5头,设相同条件下不免疫对照5头,30 d后静脉注射致死量猪霍乱沙门氏菌,临床观察30 d后评估疫苗的效力。【结果】耐热苗及常规苗的物理性状、纯粹性、活菌计数、安全性、剩余水分、真空度均符合现行《中国兽药典》的要求。3批耐热苗冻干菌存活率分别为88.2%、83.1%和86.4%,耐老化试验后的活菌存活率为83.6%、82.9%和88.8%;然而3批常规苗冻干菌存活率分别为52.3%、56.2%和61.4%,耐老化活菌存活率分别为58.5%、60.2%和54.7%。经37°C、7 d耐老化试验结果显示,耐热苗物理性状良好,而常规苗原有团块表面凹陷1/4-1/2。保存期结果表明耐热苗4°C有效期可达24个月,常规苗仅为9个月。仔猪免疫攻毒结果表明,耐热苗肌肉注射及口服免疫均达100%(5/5)保护;常规苗肌肉注射达80%(4/5)保护,口服达100%(5/5)保护,不免疫对照0保护(5/5死亡)。【结论】耐热苗具有较高的冻干菌存活率和良好的耐老化性能,4°C可长期保存且不影响其免疫效力。