Rainbow trout in seasonal environments: phenotypic trade‐offs across a gradient in winter duration

Survival through periods of resource scarcity depends on the balance between metabolic demands and energy storage. The opposing effects of predation and starvation mortality are predicted to result in trade‐offs between traits that optimize fitness during periods of resource plenty (e.g., during the growing season) and those that optimize fitness during periods of resource scarcity (e.g., during the winter). We conducted a common environment experiment with two genetically distinct strains of rainbow trout to investigate trade‐offs due to (1) the balance of growth and predation risk related to foraging rate during the growing season and (2) the allocation of energy to body size prior to the winter. Fry (age 0) from both strains were stocked into replicate natural lakes at low and high elevation that differed in winter duration (i.e., ice cover) by 59 days. Overwinter survival was lowest in the high‐elevation lakes for both strains. Activity rate and growth rate were highest at high elevation, but growing season survival did not differ between strains or between environments. Hence, we did not observe a trade‐off between growth and predation risk related to foraging rate. Growth rate also differed significantly between the strains across both environments, which suggests that growth rate is involved in local adaptation. There was not, however, a difference between strains or between environments in energy storage. Hence, we did not observe a trade‐off between growth and storage. Our findings suggest that intrinsic metabolic rate, which affects a trade‐off between growth rate and overwinter survival, may influence local adaptation in organisms that experience particularly harsh winter conditions (e.g., extended periods trapped beneath the ice in high‐elevation lakes) in some parts of their range.     

Differences in epiphyte biomass and community composition along landscape and within-crown spatial scales

Vascular epiphytes contribute to the structural, compositional, and functional complexity of tropical montane cloud forests because of their high biomass, diversity, and ability to intercept and retain water and nutrients from atmospheric sources. However, human-caused climate change and forest-to-pasture conversion are rapidly altering tropical montane cloud forests. Epiphyte communities may be particularly vulnerable to these changes because of their dependence on direct atmospheric inputs and host trees for survival. In Monteverde, Costa Rica, we measured vascular epiphyte biomass, community composition, and richness at two spatial scales: (1) along an elevation gradient spanning premontane forests to montane cloud forests and (2) within trees along branches from inner to outer crown positions. We also compared epiphyte biomass and distribution at these scales between two different land-cover types, comparing trees in closed canopy forest to isolated trees in pastures. An ordination of epiphyte communities at the level of trees grouped forested sites above versus below the cloud base, and separated forest versus pasture trees. Species richness increased with increasing elevation and decreased from inner to outer branch positions. Although richness did not differ between land-cover types, there were significant differences in community composition. The variability in epiphyte community organization between the two spatial scales and between land-cover types underscores the potential complexity of epiphyte responses to climate and land-cover changes.     

miR-188-5p suppresses cellular proliferation and migration via IL6ST: A potential noninvasive diagnostic biomarker for breast cancer

Previously, serum miR-188-5p is differentially expressed in breast cancer, but the diagnostic potential of circulating miR-188-5p as well as its regulatory mechanism in breast cancer remain uncertain. Herein, serum miR-188-5p was detected by real-time polymerase chain reaction in patients with breast cancer, breast fibroadenoma, and healthy subjects. Circulating miR-188-5p was abnormally elevated in patients with breast cancer as compared with these other two groups, and was reduced in patients with breast cancer following surgical treatment. Increased serum miR-188-5p corresponded to lymph node metastasis status and TNM stages of breast cancer. A receiver operating characteristic curve analysis of the ability to circulate miR-188-5p to distinguish between patients with breast cancer and either noncancerous patients or patients with breast fibroadenoma yielded corresponding areas under the curve of 0.894 and 8.814. miR-188-5p was downregulated in the highly malignant cancer line MDA-MB-231 relative to the less malignant MCF-7 cells. In vitro, functional analyses conducted via transfecting cells with mimics and inhibitors revealed miR-188-5p to suppress breast cancer cell proliferation and migration, which was mediated by its downstream target IL6ST. Comparison of intracellular and exosomal miR-188-5p levels indicated that miR-188-5p was selectively sorted into exosomes derived from MDA-MB-231 cells rather than those from MCF-7 cells. However, exosomal miR-188-5p levels in the serum of patients with breast cancer were reduced compared to healthy controls and did not differ relative to patients with breast fibroadenoma. In summary, miR-188-5p acts in a tumor-suppressive manner in breast cancer progression and may serve as a noninvasive early diagnostic biomarker and therapeutic target in breast cancer.     

Long‐term physiological and growth responses of Himalayan fir to environmental change are mediated by mean climate

High‐elevation forests are experiencing high rates of warming, in combination with CO₂ rise and (sometimes) drying trends. In these montane systems, the effects of environmental changes on tree growth are also modified by elevation itself, thus complicating our ability to predict effects of future climate change. Tree‐ring analysis along an elevation gradient allows quantifying effects of gradual and annual environmental changes. Here, we study long‐term physiological (ratio of internal to ambient CO₂, i.e., C_i/C_a and intrinsic water‐use efficiency, iWUE) and growth responses (tree‐ring width) of Himalayan fir (Abies spectabilis) trees in response to warming, drying, and CO₂ rise. Our study was conducted along elevational gradients in a dry and a wet region in the central Himalaya. We combined dendrochronology and stable carbon isotopes (δ¹³C) to quantify long‐term trends in C_i/C_a ratio and iWUE (δ¹³C‐derived), growth (mixed‐effects models), and evaluate climate sensitivity (correlations). We found that iWUE increased over time at all elevations, with stronger increase in the dry region. Climate–growth relations showed growth‐limiting effects of spring moisture (dry region) and summer temperature (wet region), and negative effects of temperature (dry region). We found negative growth trends at lower elevations (dry and wet regions), suggesting that continental‐scale warming and regional drying reduced tree growth. This interpretation is supported by δ¹³C‐derived long‐term physiological responses, which are consistent with responses to reduced moisture and increased vapor pressure deficit. At high elevations (wet region), we found positive growth trends, suggesting that warming has favored tree growth in regions where temperature most strongly limits growth. At lower elevations (dry and wet regions), the positive effects of CO₂ rise did not mitigate the negative effects of warming and drying on tree growth. Our results raise concerns on the productivity of Himalayan fir forests at low and middle (<3,300 m) elevations as climate change progresses.     

‘Variations in phenological and functional traits in Thapsia garganica populations in Al Jebel Al Akhdar,Libya’

Thapsia garganica is a herbaceous perennial in the Apiaceae, distributed around the Mediterranean and traditionally used in North Africa as a remedy for arthritis, herpes, hair-fall, hypertension, rheumatic, eczema and scabies. T. garganica is the source of thapsigargin: known for killing cancer cells. Seven populations were studied in sites differing in aspect and elevation within Al Jebel Al Akhdar in Libya. We studied the within-population size distribution of individuals, the timing of the phenological events, and vegetative and reproductive traits.Thapsia garganica showed high flexibility of functional traits and shifts in the timing of phenological events in response to elevation and aspect (north- or south-facing slopes). Local soil properties, together with effects due to altitude and aspect, could be direct causes of the observed differences in terms of population size and phenological traits. The phenological patterns detected also provide insights into the species response to climate change. Despite this phenotypic flexibility, and good growth in sites at 300–700 m a. s. l. on south-facing slopes, most sites in this study have an unstable size-structure, with few small individuals. This raises concerns about the long-term persistence of the other populations of this species in Al Jebel Al Akhdar.     

胸阻抗法心排血量比较直接PCI和延迟PCI对急性ST段抬高型心肌梗死患者心功能的影响

目的:采用胸阻抗法心排血量检测和比较直接和延迟经皮冠状动脉介入术(PCI)对急性ST段抬高型心肌梗死(STEMI)患者心功能的影响。方法:收集2016年1月-2018年6月于解放军南部战区海军第一医院收治的114例STEMI患者完整资料,分为直接PCI组48例,延迟PCI组40例,对照组(未行任何再灌注治疗)26例。采用胸阻抗法心排血量检测各组患者治疗后3天、6个月的每搏输出量(SV)、心指数(CI)、左心收缩力指数(CTI)、射血分数(EF)等心功能参数,并随访患者6个月内因心力衰竭再住院的情况。结果:治疗后6个月,直接PCI组和延迟PCI组SV、CI、CTI、EF均显著高于对照组,且直接PCI组SV、CTI、EF明显高于延迟PCI组,各组间差异具有统计学意义(P<0.05)。直接PCI组和延迟PCI组6个月内因心力衰竭再住院分别为2.08%和5%,均显著低于对照组(19.23%),差异具有统计学意义(P<0.05)。结论:直接和延迟PCI均能改善STEMI患者中远期心功能,且直接PCI效果更为显著。     

柠檬醛猴樟茎段组织培养技术研究

柠檬醛猴樟是重要的园林绿化、用材、油用树种。以柠檬醛猴樟一年生枝条为材料,研究采集季节、消毒时间、激素对柠檬醛猴樟茎段组织培养的影响。结果表明：5月中旬,柠檬醛猴樟半木质化茎段组织培养用浓度为0.1% HgCl₂消毒5 min,茎段腋芽萌芽率最高,褐化率和污染率较低。猴樟茎段萌芽适宜培养基为MS+1.0 mg·L^-1 6-BA+0.05 mg·L^-1 IBA,萌芽率为60%。增殖适宜培养基为MS+1.0 mg·L^-1 6-BA+0.2 mg·L^-1 IBA,增殖系数为4.33、株高为3.67 cm、地径为1.04 mm。生根培养11 d基部出现不定根,生根适宜培养基为MS+1.5 mg·L^-1 IBA,生根率75.00%、根长5.06 cm、根数3.50、根粗0.82 mm。根数大于3的组培苗,移栽成活率80%以上。     

NT-proBNP、BNP及hs-CRP在老年急性非ST段抬高型心肌梗死患者血浆中的表达及临床意义

目的:探讨N末端前体脑钠肽(NT-proBNP)、脑钠肽(BNP)及超敏C-反应蛋白(hs-CRP)在老年急性非ST段抬高型心肌梗死患者血浆中的表达及临床意义。方法:选择2015年2月～2018年7月在我院进行诊治的老年急性非ST段抬高型心肌梗死患者200例为观察组,选择同期在我院进行诊治的非冠脉综合征患者100例为对照组。入院后次日检测所有患者的血浆中的NT-proBNP、BNP及hs-CRP等指标的水平,并对比两组患者以及观察组中不同血管病变支数患者上述指标水平。两组患者均随访6个月,观察心血管不良事件的发生率。结果:观察组患者的NT-proBNP、BNP及hs-CRP水平均显著高于对照组,组间比较差异有统计学意义(P0.05)。观察组内单支血管病变、双支血管病变、三支血管病变患者间NT-proBNP、BNP及hs-CRP水平比较差异有统计学意义(P0.05),各项指标水平随着血管病变支数增加而升高(P0.05)。观察组在出院后为期6个月随访期间心血管不良事件发生率为16.50%,高于对照组心血管不良事件发生率为6.00%,组间比较差异有统计学意义(P0.05)。患者冠脉血管病变支数与血浆NT-proBNP、BNP及hs-CRP水平间呈正相关(P0.05)。结论:血浆NT-proBNP、BNP及hs-CRP水平在老年急性非ST段抬高型心肌梗死患者中显著升高,且随着患者血管病变程度的增加而升高,对患者预后心血管不良事件判断有较好的预测作用。     

半量瑞替普酶溶栓后行转运PCI与直接转运PCI对急性ST段抬高型心肌梗死临床疗效的对比研究

目的:比较急性ST段抬高型心肌梗死(STEMI)使用半量瑞替普酶溶栓后行转运经皮冠脉介入治疗(PCI)与直接转运两种救治策略的临床效果。方法:回顾性分析2015年6月～2018年2月我院收治的100例STEMI患者的病历资料,根据救治方案不同分为易化PCI组(先在基层医院经半量瑞替普酶溶栓后再转运至我院行PCI,58例)、直接转运PCI组(拒绝在基层医院接受溶栓治疗而要求直接转运PCI,42例)。比较两组PCI前后血管再通率、PCI后无复流发生率和ST段回落率(STR)、住院期间主要不良心脏事件(MACE)及治疗期间出血并发症的发生情况及随访1年主要终点事件的发生情况。结果:入院后首次冠脉造影显示易化PCI组PCI前TIMI 3级血流者占32.7%(19/59),显著高于直接转运PCI组[14.3%(6/42),P0.05]。PCI后14 d时,易化PCI组TIMI 3级血流者占93.1%(54/58),较直接转运PCI组[90.5%(38/42)]差异无统计学意义(P0.05)。PCI后即刻冠脉造影显示易化PCI组无复流发生率为6.9%(4/58),较直接转运PCI组[21.4%(9/42)]显著降低(P0.05)。PCI后24 h时,易化PCI组STR值为(61.53±11.27)%,显著高于直接转运PCI组[(52.40±12.63)%,P0.05]。住院期间,易化PCI组MACE发生率为10.3%(6/58),较直接转运PCI组[14.3%(6/42)]差异无统计意义(P0.05)。治疗期间,易化PCI组出血并发症总发生率为19.0%(11/58),与直接转运PCI组的14.3%(6/42)相比差异亦无统计学意义(P0.05)。随访1年,易化PCI组主要终点事件发生率为19.0%(11/58),显著低于直接转运PCI组[40.5%(17/42),P0.05]。结论:与直接转运PCI相比,STEMI患者应用半量瑞替普酶溶栓后行转运PCI有利于早期开通梗死血管,提高介入干预效果,PCI后获得优异的心肌灌注水平,从而改善远期预后,且安全性相当。