金川多肋骨牦牛体外触摸鉴别法的解剖学验证及应用

目的通过屠宰和解剖学试验,验证金川多肋骨牦牛体外触摸鉴别方法的准确性,为科研和生产应用建立简捷实用、准确可靠的方法。方法对试验牦牛进行触摸鉴别,根据鉴定结果,依照肋骨对数将牦牛分为A、B两组(A组具15对肋骨,B组具14对肋骨),从A、B两组中随机抽取25%的个体进行屠宰和解剖实验。应用触摸鉴别法在中心产区和分布区对15对肋骨牦牛的比例进行普查。结果触摸鉴别准确率为96.15%;19头肋骨数为15对的牦牛中,胸椎为15,腰椎数为5的个体有18头,约占95%。而腰椎数为4的个体仅1头,占5.26%;26头屠宰牦牛中,真肋+弓肋+浮肋组型为8+7+0个体的比例为68.42%;8+6+1个体比例为31.58%。结论触摸鉴别法简捷、准确率高,可以在生产和科研中推广应用;15对肋骨牦牛中,大多数个体的胸椎多出1个,而腰椎数正常,且60%以上个体肋骨组型为8+7+0,无浮肋;中心产区,多肋牦牛比例为52.08%,分布区为30.21%。     

MALDI-TOF MS analysis of the extracellular polysaccharides released by the diatom Thalassiosira pseudonana

The extracellular polysaccharides (ECPS) released by diatoms have significant roles in marine ecosystems and have potential applications including drug-discovery and biopharmaceutical precursors. In this study, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) technology was used in the structural analysis of the ECPS released by Thalassiosira pseudonana (Bacillariophyta). Three different deproteinization methods, the Sevag method, the trichloroacetic acid (TCA) method, and the enzymolysis method, were compared in the purification of ECPS. Our results suggested that TCA was the best deproteinization method among the three methods for subsequent MALDI-TOF MS investigation because of its high ECPS yield, protein removal ability and reliable MALDI-TOF MS fingerprint. The degree of polymerization (d.p.) profiles, the molecular weight of the ECPS and the distribution pattern of the polymers with different molecular mass were described from the MALDI-TOF MS spectra. This work represents the whole-level composition of the ECPS released by the diatom and has improved our knowledge of the structural characterization of ECPS.     

Substrate-Activated Conformational Switch on Chaperones Encodes a Targeting Signal in Type III Secretion

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Highlights? The targeting signal of TTS substrates to the ATPase was identified ? The ATPase engages the chaperone-substrate complex but not the free chaperone ? The ATPase recognizes a conformational change induced by the substrate to the chaperone ? Abrogation of the ternary complex results in secretion and infection defects     

Waist Circumference,Not Body Mass Index,Is Associated with Renal Function Decline in Korean Population: Hallym Aging Study

Background

Prospective investigation of obesity and renal function decline in Asia is sparse. We examined the associations of body mass index (BMI) and waist circumference (WC) with renal function decline in a prospective study of Korean population.

Methods

A total of 454 participants who had baseline estimated glomerular filtration rate (eGFR) levels of more than 60 mL/min/1.73 m² in Hallym Aging Study (HAS) were included and followed for 6 years. Renal function decline was defined as follows: (1) an eGFR decline ≥3 mL/min/1.73 m²/year (n = 82 cases); (2) an eGFR decrease of 20% or greater (n = 87 cases) at follow-up; (3) an eGFR decrease of 20% greater at follow-up or eGFR decline ≥3 mL/min/1.73 m²/year (n = 91 cases); and (4) an eGFR <60 mL/min/1.73 m² at follow-up (n = 54 cases). eGFR was determined based on the Modification of Diet in Renal Disease (MDRD) Study equation. Multivariate logistic regression model was used to determine the association between obesity and renal function decline.

Results

We found that central obesity was associated with faster renal function decline. Comparing WC of >95 cm in men or >90 cm in women with ≤90 cm in men or ≤85 cm in women, ORs (95% CIs) ranged from 2.31 (1.14–4.69) to 2.78 (1.19–6.50) for the 4 definitions of renal function decline (all p-values for trend <0.05). Waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) also was associated with renal function decline. There was no significant association of BMI with renal function decline.

Conclusions

Central obesity, but not BMI, is associated with faster renal function decline in Korean population. Our results provide important evidence that simple measurement of central fat deposition rather than BMI could predict decline in renal function in Korean population.     

P2X7 Integrates PI3K/AKT and AMPK-PRAS40-mTOR Signaling Pathways to Mediate Tumor Cell Death

Background

Extracellular adenosine triphosphate (ATP) functions as a novel danger signal that boosts antitumor immunity and can also directly kill tumor cells. We have previously reported that chronic exposure of tumor cells to ATP provokes P2X7-mediated tumor cell death, by as yet incompletely defined molecular mechanisms.

Methodology/Principal Findings

Here, we show that acute exposure of tumor cells to ATP results in rapid cytotoxic effects impacting several aspects of cell growth/survival, leading to inhibition of tumor growth in vitro and in vivo. Using agonist and antagonist studies together with generation of P2X7 deficient tumor cell lines by lentiviral shRNA delivery system, we confirm P2X7 to be the central control node transmitting extracellular ATP signals. We identify that downstream intracellular signaling regulatory networks implicate two signaling pathways: the known P2X7-PI3K/AKT axis and remarkably a novel P2X7-AMPK-PRAS40-mTOR axis. When exposed to high levels of extracellular ATP, these two signaling axes perturb the balance between growth and autophagy, thereby promoting tumor cell death.

Conclusions

Our study defines novel molecular mechanisms underpinning the antitumor actions of P2X7 and provides a further rationale for purine-based drugs in targeted cancer therapy.     

铜绿假单胞菌cntRLMN操纵子介导锌离子摄取的功能鉴定

【目的】本研究以铜绿假单胞菌PAO1 (Pseudomonas aeruginosa PAO1,菌种编号ATCC15692)为对象,研究cntRLMN在锌离子摄取中的功能。【方法】在ΔznuBC的基础上,以同源重组的方法构建了cntRLMN的各种突变菌株,通过质粒接合转移的方法构建其互补菌株及lacZ转录融合报告菌株,运用β-半乳糖苷酶酶活检测研究了Zur蛋白对cntRLMN的转录调控,凝胶阻滞实验(EMSA)检验Zur蛋白与cnt启动子及cnt启动子的突变片段的体外结合,并进一步通过生长曲线分析对cntRLMN中cntR、cntL、cntN等基因的锌离子摄取功能进行了分析和鉴定。最终,通过构建大蜡螟幼虫的侵染模型来研究cntRLMN对铜绿假单胞菌毒力发挥的影响。【结果】lacZ转录融合的酶活分析显示cntRLMN受Zur蛋白的负调控,其表达以Zur蛋白依赖的方式受锌离子饥饿的诱导;EMSA实验的结果显示cntRLMN的启动子可以与His-Zur结合形成DNA-蛋白质复合体,结合位点为GCGTTATAGTATATCAT;生长曲线和大蜡螟幼虫侵染实验的分析结果显示ZnuBC和CntRLMN的功能存在互补性,仅znuBC和cntRLMN双缺失突变时菌株在限锌培养条件下的生长和对大蜡螟幼虫的毒性才受到显著抑制,说明CntRLMN代表另一种独立的锌离子摄取系统。【结论】cntRLMN是受Zur直接负调控的另一种独立的铜绿假单胞菌锌离子摄取系统,对铜绿假单胞菌毒力的发挥起重要作用。     

Elevated Progesterone Levels on the Day of Oocyte Maturation May Affect Top Quality Embryo IVF Cycles

In contrast to the impact of elevated progesterone on endometrial receptivity, the data on whether increased progesterone levels affects the quality of embryos is still limited. This study retrospectively enrolled 4,236 fresh in vitro fertilization (IVF) cycles and sought to determine whether increased progesterone is associated with adverse outcomes with regard to top quality embryos (TQE). The results showed that the TQE rate significantly correlated with progesterone levels on the day of human chorionic gonadotropin (hCG) trigger (P = 0.009). Multivariate linear regression analysis of factors related to the TQE rate, in conventional IVF cycles, showed that the TQE rate was negatively associated with progesterone concentration on the day of hCG (OR was -1.658, 95% CI: -2.806 to -0.510, P = 0.005). When the serum progesterone level was within the interval 2.0–2.5 ng/ml, the TQE rate was significantly lower (P <0.05) than when the progesterone level was < 1.0 ng/ml; similar results were obtained for serum progesterone levels >2.5 ng/ml. Then, we choose a progesterone level at 1.5ng/ml, 2.0 ng/ml and 2.5 ng/ml as cut-off points to verify this result. We found that the TQE rate was significantly different (P <0.05) between serum progesterone levels < 2.0 ng/ml and >2.0 ng/ml. In conclusion, the results of this study clearly demonstrated a negative effect of elevated progesterone levels on the day of hCG trigger, on TQE rate, regardless of the basal FSH, the total gonadotropin, the age of the woman, or the time of ovarian stimulation. These data demonstrate that elevated progesterone levels (>2.0 ng/ml) before oocyte maturation were consistently detrimental to the oocyte.     

Possible target‐related proteins and signal network of bufalin in A549 cells suggested by both iTRAQ‐based and label‐free proteomic analysis

Bufalin (BF) exhibited antiproliferation and antimigration effects on human A549 lung cancer cells. To search its target‐related proteins, protein expression profiles of BF‐treated and control cells were compared using two quantitative proteomic methods, iTRAQ‐based and label‐free proteomic analysis. A total of 5428 proteins were identified in iTRAQ‐based analysis while 6632 proteins were identified in label‐free analysis. The number of common identified proteins of both methods was 4799 proteins. By application of 1.20‐fold for upregulated and 0.83‐fold for downregulated cutoff values, 273 and 802 differentially expressed proteins were found in iTRAQ‐based and label‐free analysis, respectively. The number of common differentially expressed proteins of both methods was 45 proteins. Results of bioinformational analysis using Metacore^TM showed that the two proteomic methods were complementary and both suggested the involvement of oxidative stress and regulation of gene expression in the effects of BF, and fibronectin‐related pathway was suggested to be an important pathway affected by BF. Western blotting assay results confirmed BF‐induced change in levels of fibronectin and other related proteins. Overexpression of fibronectin by plasmid transfection ameliorated antimigration effects of BF. Results of the present study provided information about possible target‐related proteins and signal network of BF.