Adipose triglyceride lipase regulates eicosanoid production in activated human mast cells

Human mast cells (MCs) contain TG-rich cytoplasmic lipid droplets (LDs) with high arachidonic acid (AA) content. Here, we investigated the functional role of adipose TG lipase (ATGL) in TG hydrolysis and the ensuing release of AA as substrate for eicosanoid generation by activated human primary MCs in culture. Silencing of ATGL in MCs by siRNAs induced the accumulation of neutral lipids in LDs. IgE-dependent activation of MCs triggered the secretion of the two major eicosanoids, prostaglandin D2 (PGD2) and leukotriene C4 (LTC4). The immediate release of PGD2 from the activated MCs was solely dependent on cyclooxygenase (COX) 1, while during the delayed phase of lipid mediator production, the inducible COX-2 also contributed to its release. Importantly, when ATGL-silenced MCs were activated, the secretion of both PGD2 and LTC4 was significantly reduced. Interestingly, the inhibitory effect on the release of LTC4 was even more pronounced in ATGL-silenced MCs than in cytosolic phospholipase A₂-silenced MCs. These data show that ATGL hydrolyzes AA-containing TGs present in human MC LDs and define ATGL as a novel regulator of the substrate availability of AA for eicosanoid generation upon MC activation.     

非小细胞肺癌术后并发乳糜胸对患者生活质量影响的研究

目的:探讨非小细胞肺癌术后并发乳糜胸对患者生活质量的影响。方法:采用生活质量测定量表(QLQ-C30)回顾性分析第四军医大学唐都医院胸外科自2013年至2016年中收治的1015例肺癌手术患者的生活质量,发生乳糜胸组记为A组,未发生乳糜胸组记为B组。对比术前和术后1、3、6和12个月的生活质量有无统计学差异。结果:(1)术后1月时,除了社会功能、便秘、腹泻以外,两组生活质量指标评分均显著低于术前,且B组均显著低于A组,有统计学差异(表3,P0.05)。在手术后3月及以后逐渐恢复,至12月时,各组指标与术前基本相同(表3,P0.05);(2)两组术后生活质量相比较,术后1、3月,除社会功能、便秘、腹泻以外,其余生活质量功能指标B组均显著优于A组,有统计学差异(表3,P0.05)。在手术后6月及以后,B组所有指标与A组无统计学差异(表3,P0.05)。结论:肺癌根治术后发生乳糜胸患者生活质量显著低于未发生乳糜胸患者,因此应合理选择手术方式,注意术中操作,降低乳糜胸发生率,提高肺癌患者术后的生活质量。     

Evaluating the role of livelihood assets in suitable livelihood strategies: Protocol for anti-poverty policy in the Eastern Tibetan Plateau,China

Although numerous studies have been conducted on the relationship between livelihood assets and strategies, only a few quantitative studies exist on the topic for anti-poverty policies with regard to the Tibetan Plateau. This study investigated 357 households in the upper reaches of the Dadu River watershed in the Eastern Tibetan Plateau, China, using the participatory rural appraisal method. Then, applying a multinomial logistic regression model, we quantitatively analyzed the relationship between livelihood assets and livelihood strategies, the findings of which have implications for local agricultural policy interventions. The preliminary results indicate that of the four classifications of livelihood strategies used in this study, the main livelihood strategy is that of the non-farming-dependent household type (i.e., Type III in our study) that combines agricultural and non-farm activities or practices self-employment for wages. There are significant differences in the livelihood assets owned by households with different livelihood strategies. Human, natural, and financial assets have significant influences on livelihood strategies, and the choice of livelihood strategy varies by livelihood assets. Further, with improvements in household labor capacity and cash income per capita, the livelihood strategies of non-agricultural and non-farming households may shift away from agriculture, while an increase in farmland cultivated per capita, cash income per capita, and household labor capacity may encourage households to adopt agriculture-dependent livelihood strategies. These findings contribute to research on livelihood and related development strategies and anti-poverty policies in not only the Eastern Tibetan Plateau but also other regions with similar livelihood strategies.     

The septins FaCdc3 and FaCdc12 are required for cytokinesis and affect asexual and sexual development,lipid metabolism and virulence in Fusarium asiaticum

Septins are a highly conserved family of GTP‐binding proteins that contribute to many cellular and metabolic functions, including cell polarity, cytokinesis, cell morphogenesis and pathogenesis. In this study, we characterized the septins FaCdc3 and FaCdc12 in the filamentous fungus Fusarium asiaticum. The functions of FaCdc3 and FaCdc12 were evaluated by constructing deletion mutants of FaCdc3 and FaCdc12, designated ΔFaCdc3‐5 and ΔFaCdc12‐71, respectively. The deletion mutants exhibited a reduced rate of mycelial growth, increased aerial hyphae formation, irregularly shaped hyphae, reduced conidiation and a lack of sexual reproduction in wheat kernels. Histochemical analysis revealed that the conidia and hyphae of ΔFaCdc3‐5 and ΔFaCdc12‐71 formed large lipid droplets (LDs). ΔFaCdc3‐5 and ΔFaCdc12‐71 also exhibited increased resistance to agents that induce osmotic stress and damage the cell membrane and cell wall. In addition, the hyphae and conidia of the two mutants formed fewer septa than those of the wild‐type and exhibited aberrant nuclear distribution. Pathogenicity assays showed that ΔFaCdc3‐5 and ΔFaCdc12‐71 exhibited reduced virulence on wheat spikelets, which was indirectly correlated with a reduced level of deoxynivalenol accumulation. All of these defects were restored by genetic complementation of the two mutants with the parental FaCdc3 and FaCdc12. These results indicate that FaCdc3 and FaCdc12 play a critical role in various cellular processes in F. asiaticum.     

The evolution of intermediate castration virulence and ant coexistence in a spatially structured environment

Theory suggests that spatial structuring should select for intermediate levels of virulence in parasites, but empirical tests are rare and have never been conducted with castration (sterilizing) parasites. To test this theory in a natural landscape, we construct a spatially explicit model of the symbiosis between the ant-plant Cordia nodosa and its two, protecting ant symbionts, Allomerus and Azteca . Allomerus is also a castration parasite, preventing fruiting to increase colony fecundity. Limiting the dispersal of Allomerus and host plant selects for intermediate castration virulence. Increasing the frequency of the mutualist, Azteca , selects for higher castration virulence in Allomerus , because seeds from Azteca -inhabited plants are a public good that Allomerus exploits. These results are consistent with field observations and, to our knowledge, provide the first empirical evidence supporting the hypothesis that spatial structure can reduce castration virulence and the first such evidence in a natural landscape for either mortality or castration virulence.     

Population structure and genetic diversity of Bromus tectorum within the small grain production region of the Pacific Northwest

Bromus tectorum L. is an invasive winter annual grass naturalized across the United States. Numerous studies have investigated B. tectorum population structure and genetics in the context of B. tectorum as an ecological invader of natural areas and rangeland. Despite the wealth of information regarding B. tectorum, previous studies have not focused on, or made comparisons to, B. tectorum as it persists in individual agroecosystems. The objectives of this study were to assess the genetic diversity and structure, the occurrence of generalist and specialist genotypes, and the influence of climate on distribution of B. tectorum sourced exclusively from within small grain production regions of the Pacific Northwest. Genetic diversity of B. tectorum sourced from agronomic fields was found to be similar to what has been observed from other land use histories. Six distinct genetic clusters of B. tectorum were identified, with no evidence to indicate that any of the genetic clusters were better adapted to a particular geographical area or climate within the region. Given the apparent random spatial distribution of B. tectorum genetic clusters at the spatial scale of this analysis, unique genotypes may be well mixed within region, similar to what was reported for other inbreeding weedy grass species.     

无功能垂体瘤的术后评估

垂体瘤是常见的颅内良性肿瘤,患病率高,预后较好。在我国,其发病率仅次于胶质瘤和脑膜瘤。无功能垂体瘤约占垂体瘤22.5%,手术是其首选的治疗方式,以解除肿瘤的占位效应,减少对正常垂体组织的压迫。然而手术本身可能引起垂体功能减退,术后应对患者垂体功能的监测并予以处理。同时,由于手术及患者个体身体、心理原因,患者术后的生活质量也越来越受到重视。本文综述了无功能垂体瘤患者术后各内分泌轴功能的临床检测方法,以帮助临床医生对术后患者的垂体功能进行评估并重建;同时对术后患者生活质量的评估加以讨论,帮助指导患者恢复生理及心理健康。     

Tunable luminescence and energy transfer in Ca3SiO4Cl2:Ce3+,Li+,Mn2+,Eu2+ phosphors

A series of color‐tunable Ca_{3–2x‐y‐z}SiO₄Cl₂ (CSC):xCe³⁺,xLi⁺,yMn²⁺,zEu²⁺ phosphors with low temperature phase structure was synthesized via the sol–gel method. An energy transfer process from Ce³⁺ to Mn²⁺ in CSC:0.01Ce³⁺,0.01Li⁺,yMn²⁺ (y = 0.03–0.09) and the mechanism was verified to be an electric dipole–dipole interaction. The Ce³⁺ and Mn²⁺ emission intensities were greatly enhanced by co‐doping Eu²⁺ ions into CSC:0.01Ce³⁺,0.01Li⁺,0.07Mn²⁺ phosphors due to competitive energy transfers from Eu²⁺/Ce³⁺ to Mn²⁺, and Ce³⁺ to Eu²⁺. Under 332 nm excitation, CSC:0.01Ce³⁺,0.01Li+,0.07Mn²⁺,zEu²⁺ (z = 0.0005–0.002) exhibited tunable emission colors from green to white with coexisting orange, green and violet‐blue emissions. These phosphors could have potential application in white light‐emitting diodes.     

Identification of cardiac stem cells within mature cardiac myocytes

Cardiac stem cells are described in a number of mammalian species including humans. Cardiac stem cell clusters consisting of both lineage-negative and partially committed cells are generally identified between contracting cardiac myocytes. In the present study, c-kit⁺, Sca⁺, and Isl1⁺ stem cells were revealed to be located inside the sarcoplasm of cardiac myocytes in myocardial cell cultures derived from newborn, 20-, and 40-day-old rats. Intracellularly localized cardiac stem cells had a coating or capsule with a few pores that opened into the host cell sarcoplasm. The similar structures were also identified in the suspension of freshly isolated myocardial cells (ex vivo) of 20- and 40-day-old rats. The results from this study provide direct evidence for the replicative division of encapsulated stem cells, followed by their partial cardiomyogenic differentiation. The latter is substantiated by the release of multiple transient amplifying cells following the capsule rupture. In conclusion, functional cardiac stem cells can reside not only exterior to but also within cardiomyocytes.