Some are more equal than others

The microbial communities found in the mammalian large intestine and rumen efficiently degrade many recalcitrant substrates that are resistant to the host’s digestive enzymes. These communities are known from molecular profiling to be highly diverse at the species and strain level, but it may be that only certain specialized organisms (“keystone species”) have the ability to initiate degradation of such substrates, thus releasing energy on which the rest of the community depends. We have recently reported that Ruminococcus bromii has a superior ability to degrade certain forms of particulate resistant starch (RS) when compared with other highly abundant species of amylolytic bacteria found in the human colon and have presented evidence that this bacterium provides an example of a keystone species within the microbial community with respect to RS fermentation. The concept of keystone species can be equally relevant to other activities, e.g., those involved in stabilizing the community.     

羟丙基淀粉空心胶囊对螺内酯含量的影响

摘 要 目的： 考察羟丙基淀粉胶囊对螺内酯胶囊主药含量的影响。方法: 分别在强光（4 000 Lx±500 Lx）、高温（40℃）、高湿（相对湿度75%±5%）的条件下放置5 d和10 d,采用高效液相色谱法检查样品放置前后含量改变,同时观察外观、色泽等药物性状的变化。结果:经高温、高湿、光照试验后,测得标示含量值均在93.45%～100.37%之间,符合标准规定（93.0%～107.0%）。结论: 羟丙基淀粉空心胶囊与螺内酯相容性较好。     

Sweet potato leaf extract inhibits the simulated in vitro gastrointestinal digestion of native starch

Several studies have reported the therapeutic use of caffeoylquinic acid (CQA) derivatives in the management of hyperglycemia. This study used a simulated in vitro gastrointestinal digestion model to assess the inhibitory effects of CQA derivatives-rich sweet potato leaf extract (SPLE) and a commercially produced green coffee bean extract (GCBE), each with total polyphenols contents of 452 mg g⁻¹ and 278 mg g⁻¹, respectively, against starch digestion. The changes in the amounts of total polyphenols and total CQA derivatives during in vitro gastrointestinal digestion were also examined. The results indicated that both extracts contained substantial levels of CQA derivatives (136 mg g⁻¹ and 83.5 mg g⁻¹ of extract for SPLE and GCBE, respectively). The amounts of total polyphenols and total CQA derivatives in 20 mg of SPLE and GCBE samples decreased from 9.04 mg to 0.58 mg and from 5.56 mg to 0.58 mg, and from 2.72 mg to 0.16 mg and from 1.67 mg to 0.10 mg, respectively, following in vitro gastrointestinal digestion and subsequent dialysis. When SPLE and GCBE were accompanied with starch for in vitro digestion test, they both exhibited inhibitory effect against starch digestion during simulated intestinal digestion, with estimated half maximal inhibitory concentration (IC₅₀) values of 4.91 mg and 6.06 mg polyphenols, respectively. The amount of glucose permeated through dialysis membrane also decreased significantly in comparison with the extract-negative control. Thus, both SPLE and GCBE were capable of modulating the release of glucose from starch digestion in simulated intestinal tract. The observed inhibitory effects against glucose release were presumably due in part to the presence of CQA derivatives in the tested extracts. The SPLE had higher inhibitory effect against in vitro starch digestion than the commercially prepared reference GCBE. Therefore, the SPLE might be used to manage hyperglycemia over the long term.     

Sorghum resistant starch reduces adiposity in high-fat diet-induced overweight and obese rats via mechanisms involving adipokines and intestinal flora

Resistant starch, as a source of energy for the beneficial bacteria in intestine, may have beneficial health effects, limiting your risk for obesity and colon problems. This study evaluated the effects of sorghum resistant starch (SRS) on the changes of body weight, blood lipid and the population of intestinal flora in the colon of high-fat diet-induced (HFD) overweight and obese rats which contained 60 rats. Sixty male rats were divided into five groups of normal control group (NC), model control group (MC A), model control group (MC B), sorghum resistant starch A group (SRS A) and sorghum resistant starch B group (SRS B) which administrated standard diet, diets A and B. The results indicated that SRS helps the body prevent and treat obesity through mechanisms including synthesis and secretion of leptin (LP) and adiponcetin (ADP) and improvement in intestinal flora.     

Immobilization of amyloglucosidase onto macroporous cryogels for continuous glucose production from starch

Poly(methyl methacrylate-glycidyl methacrylate) [Poly(MMA-GMA)] cryogels were synthesized using monomers of methylmethacrylic acid and epoxy group bearing GMA via radical cryopolymerization technique. Synthesized cryogels were used for the immobilization of amyloglucosidase to the cryogel surface using epoxy chemistry. Characterizations of the free and immobilized amyloglucosidase were carried out by comparing the optimum and kinetic parameters of enzymes. For this, pH and temperature profiles of free and immobilized preparation were studied and, it was found that, optimum pH of enzyme was not change upon immobilization (pH 5.0), while optimum temperature of the enzyme shifted 10 °C to warmer region after immobilization (optimum temperatures for free and immobilized enzyme were 55 and 65 °C, respectively). Kinetic parameters of free and immobilized enzyme were also investigated and K_m values of free and immobilized amyloglucosidase were found to be 2.743 and 0.865 mg/mL, respectively. V_max of immobilized amyloglucosidase was found to be (0.496 µmol/min) about four times less than that of free enzyme (2.020 µmol/min). Storage and operational stabilities of immobilized amyloglucosidase were also studied and it was showed that immobilized preparation had much more stability than free preparation. In the present work, amyloglucosidase immobilized poly(MMA-GMA) cryogels were used for continuous glucose syrup production from starch for the first time. Efficiency of immobilized enzyme was investigated and released amount of glucose was found to be 2.54 mg/mL at the end of the 5 min of hydrolysis. The results indicate that the epoxy functionalized cryogels offer a good alternative for amyloglucosidase immobilization applications with increased operational and thermal stability, and reusability. Also, these cryogels can be used for immobilization of other industrially valuable enzymes beyond amyloglucosidase.     

Benefits of resistant starch type 2 for patients with end-stage renal disease under maintenance hemodialysis: a systematic review and meta-analysis

Background: Resistant starch type 2 (RS2) has been documented to regulate gut microbiota and to improve the clinical outcomes of several diseases. However, whether RS2 may benefit patients with end-stage renal disease under maintenance hemodialysis (MHD) remains unknown.Methods: We conducted a systemic review and meta-analysis of randomized controlled trials (RCTs). Adult patients receiving MHD were treated with RS2 (CRD42020160332). The primary outcomes were changes of uremic toxins, and the secondary outcomes were changes of inflammatory indicators, albumin and phosphorus.Results: After screening 65 records, five RCTs (n = 179) were included. A significant decrease of blood urea nitrogen (weighted mean difference (WMD) = -6.91, 95% CI: -11.87 to -1.95, I² = 0%, P = 0.006), serum creatinine (WMD = -1.11, 95% CI: -2.18 to -0.05, I² = 44%, P = 0.04) and interleukin (IL)-6 in blood (standard mean difference (SMD) = -1.08, 95% CI: -1.64 to -0.53, I² = 35%, P = 0.0001) was revealed in the RS2 group. Analyses of blood levels of uric acid, p-cresyl sulfate, indoxyl sulfate, high sensitive C-reaction protein, albumin and phosphorus yielded no significant difference.Conclusions: Our results suggest that RS2 may improve the residual renal function of patients under MHD and mitigate a proinflammatory response.     

Hydroxyethyl starch is an alternative washing solution for peripheral bloodstem cells products

Cryopreservation of hematopoietic stem cells (HSC) involves slow rate cooling in the presence of a cryoprotectant (DMSO) to avoid the damaging effects of intracellular ice formation. The infusion of DMSO with the thawed product has been related to adverse events. Reduction of DMSO content by washing the HSCs after thawing has been suggested as a method to avoid infusion-related side-effects. Albumin-dextran washing methods have proved useful in thawing HSC products. Dextran40 shortages prompted us to search for suitable alternatives. We report the results of a comparative study of the use of hydroxyethyl starch (HES) as an alternative to dextran40 for washing thawed HSCs products. A total of 10 HSC bags cryopreserved with 10 % DMSO were used. We conducted a paired study; one of the bags was thawed and washed with our standard washing solution (Dextran 40) and the paired bag with HES solution with a final HES and Human Serum Albumin (HSA) concentration of 2.4 % and 4.2 % respectively. Each final product was tested immediately after washing (sample 0’) and after 90 min (sample 90’) for total nucleated cells (TNC) recovery, acridine orange viability, viable CD34+ enumeration, and clonogenicity. No significant difference was found for any of the cell counts, viability tests, cell recovery, or potency. We can state that the washing solution based on 2.4 % HES and 4.2 % HSA is equivalent to that used in our routine practice. Therefore, we could use the solution with HES, paying special attention to the renal function of the recipient.     

高渗羟乙基淀粉(200/0.5)氯化钠注射液用于择期颅脑手术麻醉效果探讨

目的 探讨高渗羟乙基淀粉(200/0.5)氯化钠注射液用于择期颅脑手术麻醉对患者血流动力学、电解质酸碱平衡及降低颅内压效果的影响.方法 选取行择期胶质瘤切除手术患者120例,以随机抽样方法分为对照组(60例)和高渗组(60例);分别给予常规羟乙基淀粉和高渗羟乙基淀粉(200/0.5)静脉输注,比较两组患者不同时间点心率(HR),平均动脉压(MAP),中心静脉压(CVP),Na+、K+、Ca2+、pH及颅内压(ICP)等指标水平.结果 两组患者T2、T3及T4时间点HR和CVP指标均较T0时间点明显提高,差异有统计学意义(P＜0.05);两组患者T3和T4时间点MAP指标均较T0时间点显著降低,差异有统计学意义(P＜0.05);而高渗组患者T4时间点HR和MAP指标水平均明显优于对照组,差异有统计学意义(P＜0.05);两组患者T1、T2、T3及T4时间点Na+和K+指标水平与T0时间点比较差异有统计学意义(P＜0.05);两组患者T2、T3及T4时间点ICP水平较T0时间点均显著降低,差异有统计学意义(P＜0.05);高渗组患者T4时间点ICP水平显著低于对照组,差异有统计学意义(P＜0.05).结论 高渗羟乙基淀粉(200/0.5)氯化钠注射液用于行颅脑外科手术治疗患者可有效稳定血流动力学,纠正电解质酸碱平衡平衡紊乱,并抑制颅内压升高.     

Comparing Triflate and Hexafluorophosphate Anions of Ionic Liquids in Polymer Electrolytes for Supercapacitor Applications

Two different ionic liquid-based biopolymer electrolyte systems were prepared using a solution casting technique. Corn starch and lithium hexafluorophosphate (LiPF₆) were employed as polymer and salt, respectively. Additionally, two different counteranions of ionic liquids, viz. 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF₆) and 1-butyl-3-methylimidazolium trifluoromethanesulfonate (also known as 1-butyl-3-methylimidazolium triflate) (BmImTf) were used and studied in this present work. The maximum ionic conductivities of (1.47 ± 0.02) × 10⁻⁴ and (3.21 ± 0.01) × 10⁻⁴ S·cm⁻¹ were achieved with adulteration of 50 wt% of BmImPF₆ and 80 wt% of BmImTf, respectively at ambient temperature. Activated carbon-based electrodes were prepared and used in supercapacitor fabrication. Supercapacitors were then assembled using the most conducting polymer electrolyte from each system. The electrochemical properties of the supercapacitors were then analyzed. The supercapacitor containing the triflate-based biopolymer electrolyte depicted a higher specific capacitance with a wider electrochemical stability window compared to that of the hexafluorophosphate system.     

羟乙基淀粉注射液致急性肾损伤的危险因素分析

目的 探讨羟乙基淀粉注射液致急性肾损伤（AKI）的危险因素,为临床安全用药提供参考。方法 回顾性分析2015年1月—2019年3月衡水市人民医院86例羟乙基淀粉注射液致AKI和同期使用羟乙基淀粉注射液但未发生AKI的767例患者的临床资料,采用单因素（χ²检验）及多因素（Logistic回归）对肾毒性危险因素进行分析。结果 AKI是羟乙基淀粉注射液严重不良反应之一,发生率为10.08%。单因素分析显示,体重指数、低蛋白血症、肌酐清除率、合并肾毒性药物、术中出血量、日剂量和用药时间与羟乙基淀粉肾毒性相关;多因素分析显示,日剂量（≥14 mL/kg）、肌酐清除率（<30mL/min）、用药时间（≥5 d）、术中出血量（>3 000 mL）、合并肾毒性药物和低蛋白血症（ALB<30 mL/L）是羟乙基淀粉130/0.4氯化钠注射液致AKI的独立危险因素。所有患者停药或经相关治疗后肾功能均逐渐恢复。结论 日剂量偏大、肾功能不全、长时间用药、术中出血量偏大、合并肾毒性药物和低蛋白血症是羟乙基淀粉致AKI的独立危险因素,临床中重点关注有独立危险因素的患者,以保证临床安全用药。