微生态制剂对细菌性痢疾的辅助治疗及对患者血清C反应蛋白水平的影响

目的探讨微生态制剂对细菌性痢疾的辅助治疗及对患者血清C反应蛋白(CRP)水平的影响。方法选取2016年3月至2018年10月在我院门诊接受治疗的86例细菌性痢疾患者为研究对象,入选患者随机分为对照组和观察组,每组43例。对照组患者给予常规药物进行治疗,观察组患者在此基础上加用布拉氏酵母菌散辅助治疗。比较两组患者临床疗效,不良反应发生率及血清CRP水平。结果治疗后观察组患者临床总有效率为90.40%,显著高于对照组的69.77%,差异有统计学意义(χ^2=5.939,P=0.015)。观察组患者不良反应发生率为9.3%,显著低于对照组的34.88%,差异有统计学意义(χ^2=8.174,P=0.004)。同时,观察组患者治疗后血清CRP水平为(4.32±0.43)mg/L,显著低于对照组的(7.03±0.32)mg/L,差异有统计学意义(t=33.154,P<0.001)。结论微生态制剂辅助治疗细菌性痢疾的临床疗效优于常规治疗方法,能降低患者血清CRP水平,减少患者不良反应,安全有效,值得临床推广。     

Proteome comparison of hypopharyngeal gland development between Italian and royal jelly producing worker honeybees (Apis mellifera L.)

The hypopharyngeal gland (HG) of the honeybee (Apis mellifera L.) produces royal jelly (RJ) that is essential to feed and raise broods and queens. A strain of bees (high royal jelly producing bee, RJb) has been selected for its high RJ production, but the mechanisms of its higher yield are not understood. In this study, we compared HG acini size, RJ production, and protein differential expressions between the RJb and nonselected honeybee (Italian bee, ITb) using proteomics in combination with an electron microscopy, Western blot, and quantitative real-time PCR (qRT-PCR). Generally, the HG of both bees showed age-dependent changes in acini sizes and protein expression as worker behaviors changed from brood nursing to nectar ripening, foraging, and storage activities. The electron microscopic analysis revealed that the HG acini diameter of the RJb strain was large and produced 5 times more RJ than the ITb, demonstrating a positive correlation between the yield and HG acini size. In addition, the proteomic analysis showed that RJb significantly upregulated a large group of proteins involved in carbohydrate metabolism and energy production, those involved in protein biosynthesis, development, amino acid metabolism, nucleotide and fatty acid, transporter, protein folding, cytoskeleton, and antioxidation, which coincides with the fact that the HGs of the RJb strain produce more RJ than the ITb strain that is owing to selection pressure. We also observed age-dependent major royal jelly proteins (MRJPs) changing both in form and expressional intensity concurrent with task-switching. In addition to MRJPs, the RJb overexpressed proteins such as enolase and transitional endoplasmic reticulum ATPase, protein biosynthesis, and development proteins compared to the ITb strain to support its large HG growth and RJ secretion. Because of selection pressure, RJb pursued a different strategy of increased RJ production by involving additional proteins compared to its original counterpart ITb. To our knowledge, this morphological and proteomic comparison study on the HG of the two strains of worker honeybees associated with their age-dependent division of labor is the first of its kind. The study provided not only the quantity and quality differences in the HG from the RJb and the ITb, but also addressed the cellular and behavioral biology development question of how the RJb strain can produce RJ more efficiently than its wild type strain (ITb).     

Retention of Virulence in a Viable but Nonculturable Edwardsiella tarda Isolate

Edwardsiella tarda is pathogen of fish and other animals. The aim of this study was to investigate the viable but nonculturable (VBNC) state and virulence retention of this bacterium. Edwardsiella tarda CW7 was cultured in sterilized aged seawater at 4°C. Total cell counts remained constant throughout the 28-day period by acridine orange direct counting, while plate counts declined to undetectable levels (<0.1 CFU/ml) within 28 days by plate counting. The direct viable counts, on the other hand, declined to ca. 10⁹ CFU/ml active cells and remained fairly constant at this level by direct viable counting. These results indicated that a large population of cells existed in a viable but nonculturable state. VBNC E. tarda CW7 could resuscitate in experimental chick embryos and in the presence of nutrition with a temperature upshift. The resuscitative times were 6 days and 8 days, respectively. The morphological changes of VBNC, normal, and resuscitative E. tarda CW7 cells were studied with a scanning electron microscope. The results showed that when the cells entered into the VBNC state, they gradually changed in shape from short rods to coccoid and decreased in size, but the resuscitative cells did not show any obvious differences from the normal cells. The VBNC and the resuscitative E. tarda CW7 cells were intraperitoneally inoculated into turbot separately, and the fish inoculated with the resuscitative cells died within 7 days, which suggested that VBNC E. tarda CW7 might retain pathogenicity.     

Differential mitochondrial calcium responses in different cell types detected with a mitochondrial calcium fluorescent indicator, mito-GCaMP2

Mitochondrial calcium plays a crucial role in mitochondrial metabolism, cell calcium handling, and cell death. However, some mechanisms concerning mitochondrial calcium regulation are still unknown, especially how mitochondrial calcium couples with cytosolic calcium. In this work, we constructed a novel mitochondrial calcium fluorescent indicator (mito-GCaMP2) by genetic manipulation. Mito-GCaMP2 was imported into mitochondria with high efficiency and the fluorescent signals co-localized with that of tetramethyl rhodamine methyl ester, a mitochondrial membrane potential indicator. The mitochondrial inhibitors specifically decreased the signals of mito-GCaMP2. The apparent K(d) of mito-GCaMP2 was 195.0 nmol/L at pH 8.0 in adult rat cardiomyocytes. Furthermore, we observed that mito-GCaMP2 preferred the alkaline pH surrounding of mitochondria. In HeLa cells, we found that mitochondrial calcium ([Ca(2+)](mito)) responded to the changes of cytosolic calcium ([Ca(2+)](cyto)) induced by histamine or thapasigargin. Moreover, external Ca(2+) (100 μmol/L) directly induced an increase of [Ca(2+)](mito) in permeabilized HeLa cells. However, in rat cardiomyocytes [Ca(2+)](mito) did not respond to cytosolic calcium transients stimulated by electric pacing or caffeine. In permeabilized cardiomyocytes, 600 nmol/L free Ca(2+) repeatedly increased the fluorescent signals of mito-GCaMP2, which excluded the possibility that mito-GCaMP2 lost its function in cardiomyocytes mitochondria. These results showed that the response of mitochondrial calcium is diverse in different cell lineages and suggested that mitochondria in cardiomyocytes may have a special defense mechanism to control calcium flux.     

青弋江流域生态系统服务评估与权衡研究

研究生态系统服务价值变化特征及多种服务之间的权衡协同关系,对平衡经济发展与环境保护具有重要意义。基于修订的当量因子表,结合2000、2009、2018年3个时期遥感解译获取的土地利用数据,运用生态系统服务权衡协同度模型、敏感性分析、空间自相关、土地利用程度综合指数模型等分析了青弋江流域生态系统服务价值（Ecosystem Services Value,ESV）的时空演变特征及9种生态服务之间的权衡协同关系。结果表明：（1）2000、2009及2018年的生态系统服务价值分别为285.19、351.26和294.68亿元,价值总量呈先增后减的变化趋势,其中2009-2018年间总ESV下降了16.1%,生态服务趋于退化。整个研究时段内,林地对ESV的贡献量最大,其次是耕地和水域。（2）2000-2009年,单项生态系统服务间以协同关系为主导,协同率为77.8%,食物生产服务与本研究中的其他服务之间均为权衡关系;2009-2018年间生态系统服务间的关系与前9年基本一致,但食物生产服务与其他服务功能之间的权衡度呈增强的趋势。（3）敏感性分析表明,各时期的敏感性指数（CS）值均小于1,表明基于修订的当量因子表计算获得的生态系统服务价值系数符合青弋江流域的实际情况,计算结果可靠。（4）生态系统服务价值存在较强的正向空间自相关,但集聚程度有下降的趋势。双变量空间自相关分析表明当土地利用程度增强时,生态系统提供的总服务价值或单项服务价值均会降低。研究结果可为青弋江流域土地利用结构的优化调整及生态环境保护提供参考信息。     

Native Magnetic Resonance T1-Mapping Identifies Diffuse Myocardial Injury in Hypothyroidism

Background and Aim

Hypothyroidism (HT) is characterized by thyroid hormone deficiencies, which can lead to diffuse myocardial interstitium lesions in patients with HT. Myocardial longitudinal relaxation time (T1) mapping is a potential diagnostic tool for quantifying diffuse myocardial injury. This study aimed to assess the usefulness of T1 mapping in identifying myocardial involvement in HT, and determine the relationship between T1 values and myocardial function.

Methods

A cross-sectional study was conducted with 30 untreated HT patients alongside 23 age- and sex-matched healthy controls. All subjects underwent cardiac magnetic resonance (CMR) with non-contrast (native) T1 mapping using a modified Look-Locker inversion-recovery (MOLLI) sequence to assess the native T1 values of myocardium and cardiac function.

Results

Native myocardial T1 values were significantly increased in HT patients, especially those with pericardial effusion (p < 0.05), compared with healthy controls. In addition, significantly reduced peak filling rate (PFR) and prolonged peak filling time (PFT) were obtained (p < 0.05) in HT patients compared with controls. Furthermore, stroke volume (SV) and cardiac index (CI) were significantly lower in HT patients than controls (all p < 0.05). Interestingly, native T1 values were negatively correlated with free triiodothyronine (FT3), PFR, SV and CI (all p < 0.05).

Conclusion

Diffuse myocardial injuries are common in HT patients, and increased T1 values are correlated with FT3 and cardiac function impairment. These findings indicate that T1 mapping might be useful in evaluating myocardial injuries in HT patients.     

FGF21 Prevents Angiotensin II-Induced Hypertension and Vascular Dysfunction by Activation of ACE2/Angiotensin-(1–7) Axis in Mice

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Proteome changes underpin improved meat quality and yield of chickens (Gallus gallus) fed the probiotic Enterococcus faecium

Background

Supplementation of broiler chicken diets with probiotics may improve carcass characteristics and meat quality. However, the underlying molecular mechanism remains unclear. In the present study, 2D-DIGE-based proteomics was employed to investigate the proteome changes associated with improved carcass traits and meat quality of Arbor Acres broilers (Gallus gallus) fed the probiotic Enterococcus faecium.

Results

The probiotic significantly increased meat colour, water holding capacity and pH of pectoral muscle but decreased abdominal fat content. These meat quality changes were related to the altered abundance of 22 proteins in the pectoral muscle following E. faecium feeding. Of these, 17 proteins have central roles in regulating meat quality due to their biological interaction network. Altered cytoskeletal and chaperon protein expression also contribute to improved water holding capacity and colour of meat, which suggests that upregulation of chaperon proteins maintains cell integrity and prevents moisture loss by enhancing folding and recovery of the membrane and cytoskeletal proteins. The down-regulation of β-enolase and pyruvate kinase muscle isozymes suggests roles in increasing the pH of meat by decreasing the production of lactic acid. The validity of the proteomics results was further confirmed by qPCR.

Conclusions

This study reveals that improved meat quality of broilers fed probiotics is triggered by proteome alterations (especially the glycolytic proteins), and provides a new insight into the mechanism by which probiotics improve poultry production.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1167) contains supplementary material, which is available to authorized users.     

Production of a Class IIb Bacteriocin with Broad-spectrum Antimicrobial Activity in Lactiplantibacillus plantarum RUB1

Bacteriocins produced by lactic acid bacteria have potential use as natural food preservatives, which may alleviate current problems associated with the overuse of antibiotics and emerging multi-drug-resistant microbes. In this work, Lactiplantibacillus plantarum RUB1 was found to produce a class IIb bacteriocin with strong antibacterial activity. Except for plnXY encoding putative proteins, L. plantarum RUB1 contains most genes in five operons (plnABCD, plnGHSTUVW, plnMNOP, plnIEF, and plnRLJK) related to bacteriocin synthesis. Adding low (100 and 500 ng/mL) and medium (1 μg/mL) concentrations of PlnA to broth promoted bacteriocin production and upregulated bacteriocin gene plnA, while high concentrations (50 and 200 μg/mL) inhibited expression of these genes. Co-culturing L. plantarum RUB1 with Enterococcus hirae 1003, Enterococcus hirae LWS, Limosilactobacillus fermentum RC4, L. plantarum B6, and even Listeria monocytogenes ATCC 19111 and Staphylococcus aureus ATCC 6538 enhanced bacteriocin activity and expression of bacteriocin-related genes. This study verifies that PlnA can indeed upregulate the expression of bacteriocin genes, and also bacteriocin production can be induced by co-culture with some specific bacteria or their cell-free supernatants. Bacteriocin production by L. plantarum RUB1 is mediated by a quorum sensing mechanism, directly influenced by autoinducing peptide or specific strains. The findings provide new methods and insight into bacteriocin production mechanisms.