异甘草酸镁治疗大鼠非酒精性脂肪性肝炎及其作用机制

目的探讨异甘草酸镁对非酒精性脂肪性肝炎（NASH）的治疗作用及其作用机制。方法雄性SD大鼠50只随机分为5组：正常组（N组）普通饲料喂养;模型Ⅰ组（M1组）和模型Ⅱ组（M2组）高脂饲料喂养;异甘草酸镁治疗组（T1组）和饮食治疗组（T2组）在喂饲高脂饲料12周后改为普通饲料喂养,其中T2组同时给予异甘草酸镁120 mg.kg-1.d-1尾静脉注射。12周末处死N和M1组大鼠;16周末处死M2、T1和T2组大鼠。观察各组大鼠肝脏组织病理学改变,并测定各组大鼠肝功能（血清AST、ALT）、脂代谢（血清TC、TG、HDL、LDL-C）及脂质过氧化（肝匀浆MDA、SOD、GSH）指标。结果 12周末M1组大鼠出现NASH,肝脏的脂肪变性程度和炎症活动度均显著增高,TC、TG、LDL-C、MDA明显升高,HDL、SOD和GSH明显降低（P〈0.05）;16周末,M2组大鼠NASH程度进一步加重,并出现AST和ALT的明显升高（P〈0.05）。和M1、M2组相比,T1组脂肪变性和炎症活动程度明显减轻,肝功能、脂代谢和脂质过氧化各项指标均改善（P〈0.05）;而T2组差异无统计学意义（P〉0.05）。结论异甘草酸镁可能通过抗脂质过氧化、调节血脂代谢、抑制炎症反应等作用减轻NASH大鼠肝脂肪变性和炎症,对NASH有治疗作用。     

Plasma magnesium should be monitored perioperatively in patients undergoing colorectal resection

Objective Hypomagnesemia has been shown to have several clinically important sequelae. The aims of this study were: to assess the impact of bowel preparation, with sodium picosulphate (Picolax®), on plasma electrolytes, with particular regard to plasma magnesium, in patients undergoing bowel preparation for colonoscopy and colorectal resection and to evaluate the influence of perioperative magnesium levels on postoperative cardiac dysrhythmias. Method Sixty‐one patients receiving sodium picosulphate (Picolax®) bowel preparation were studied in two groups: Colonoscopy (31 patients) and Colorectal resection (30 patients). Plasma sodium, potassium, magnesium, calcium, urea, creatinine and blood haematocrit were measured in all patients prior to commencement of bowel preparation, at the time of colonoscopy or colorectal resection and 24 h postoperatively (surgery group only). Mean electrolyte and haematocrit levels were then compared. Postoperative cardiac dysrhythmias were recorded and analysed. Results No significant changes following bowel preparation were observed in plasma sodium, potassium, calcium or creatinine. Plasma urea fell following bowel preparation (colonoscopy P < 0.001, resection P = 0.004) and rose following resection (P = 0.002). Magnesium levels increased following bowel preparation in both groups (colonoscopy P < 0.001, resection P = 0.007) and fell following resection (P < 0.001). Thirty‐four per cent (21/60 patients) were hypermagnesemic following bowel preparation and 20% (6/30 patients) became hypomagnesemic following surgery. Postoperative cardiac dysrhythmias were associated with lower magnesium levels at induction and postoperatively (P = 0.022 and P = 0.033). Conclusion Bowel preparation with Picolax® does not appear to cause significant electrolyte disturbance, except in elevating plasma magnesium. Postcolorectal resection plasma magnesium dropped significantly suggesting perioperative monitoring and replacement should be routine following colorectal surgery.     

孟鲁司特钠联合硫酸镁治疗老年支气管哮喘的疗效观察

目的：探讨孟鲁司特钠联合硫酸镁治疗老年支气管哮喘的临床疗效。方法选取2012年6月至2013年6月玉林市第二人民医院收治的老年支气管哮喘患者80例,按照随机数字表法分为观察组与对照组各40例。对照组给予吸氧、抗感染、祛痰、β2受体激动剂、糖皮质激素等常规治疗,观察组在对照组的基础上加用孟鲁司特钠片和硫酸镁注射液治疗。观察并比较两组的临床疗效。结果观察组总有效率为97．1％明显高于对照组的77．1％,复发率为5．7％明显低于对照组的28．6％,差异均有统计学意义（ P＜0．05）;观察组喘息、咳嗽及胸闷等症状缓解时间均明显早于对照组,差异有统计学意义（P＜0．05）。两组患者治疗前肺功能指标比较,差异无统计学意义（P＞0．05）;治疗后肺功能指标较治疗前均明显改善,观察组改善程度优于对照组,差异有统计学意义（P＜0．05）。两组均未见呼吸抑制、血压下降等严重不良反应。结论孟鲁司特钠片联合硫酸镁注射液治疗老年支气管哮喘临床疗效显著,症状缓解快,复发率低,安全可靠,值得临床推广。     

门冬氨酸钾镁预防心脏手术后心律失常疗效的Meta分析

目的系统评价门冬氨酸钾镁预防心脏手术后心律失常的临床疗效。方法计算机检索PubMed、EMbase、The Cochrane Library(2014年第5期)、CNKI、VIP和WanFang Data,查找门冬氨酸钾镁预防心脏手术后心律失常的随机对照试验(RCT),检索时限均为从建库至2014年5月。由2位评价员按照纳入与排除标准独立筛选文献、提取资料和评价纳入研究的方法学质量后,采用RevMan 5.2软件进行Meta分析。结果最终纳入9个RCT,共825例患者。Meta分析结果显示:1与对照组相比,手术前后及时给予门冬氨酸钾镁补充钾、镁离子能明显减少心律失常的发生[OR=0.25,95%CI(0.09,0.69),P=0.008],两组差异有统计学意义。2与对照组相比,手术前后及时给予门冬氨酸钾镁补充钾、镁离子能减少早搏[OR=0.08,95%CI(0.03,0.23),P<0.000 01]和心动过速的发生率[OR=0.29,95%CI(0.17,0.49),P<0.000 01],降低24小时低心排发生率[OR=0.27,95%CI(0.10,0.72),P=0.009],提高自动复跳率[OR=12.16,95%CI(4.82,30.68),P<0.000 01],两组差异均有统计学意义。4两者在改善房颤[OR=0.05,95%CI(–0.16,0.05),P=0.34]和室颤[OR=1.24,95%CI(0.73,2.13),P=0.43]方面无明显差异。结论门冬氨酸钾镁能有效预防心脏手术后心律失常发生,同时对心肌具有一定保护作用,但在改善患者术后房颤、室颤发生率方面与常规治疗无明显差异。受纳入研究数量和质量所限,上述结论尚待进一步开展更多大样本、多中心、高质量的RCT加以验证。     

One-year death rate in 270 patients with suspected acute myocardial infarction, initially treated with intravenous magnesium or placebo

In a double-blind, placebo-controlled study, 273 patients with suspected acute myocardial infarction (AMI) were randomized to receive either 48-h magnesium (Mg) or placebo therapy intravenously, initiated immediately on admission to hospital. We describe the results from a 1-year survey in 270 of the patients, who were available for follow-up. Patients were equally divided: 135 received Mg and 135 received placebo. Mg treatment was associated with a marked reduction in 1-year death rate from 32% in the placebo group to 20% in the Mg group (p = 0.018). If only death from ischemic heart disease is considered, the figures were 28% in the placebo group as opposed to 15% in the Mg group (p = 0.006). This reduction was mainly due to a reduction in mortality during the initial 30 days after inclusion in the study (17% vs. 7%), after which the difference in mortality between the two groups did not reach statistical significance (18% vs. 15%, p = 0.56). The beneficial effect of Mg on mortality was partly linked to a reduced incidence of arrhythmias (27% vs. 16%), and partly to a reduced incidence of infarction (63% vs. 48%) during the initial hospitalization. However, factors unknown to us were also involved, as revealed by a remaining statistically significant partial regression coefficient, when sex, age, cardiovascular history, development of AMI, and development of arrhythmias were considered. It is concluded that intravenous Mg treatment is beneficial to patients with acute ischemic heart disease and should be adopted as part of the routine treatment of these patients.     

硼镁石粉灭螺研究

目的观察硼镁石粉室内灭螺效果和现场应用效果。方法室内试验和现场试验 ,参照徐国余方法 [1 ] ,现场试验面积每块 1 5 m2 。现场应用 ,冬春季用手撒硼镁石粉 80 g/ m2 ;重点环境灭螺 ,1 60 g/ m2 ～ 2 5 0 g/ m2 。结果室内试验 ,40 g/ m2 ,2 5℃ ,7d后钉螺死亡率 95 .0 %。现场试验 ,80 g/ m2 ,3 0 d,钉螺死亡率 90 .9%。现场应用 :江浦县江滩 2 0 0 0 0 0 m2 ,80 g/ m2 ,灭后 3 0 d,钉螺死亡率 90 .6%。7个区县重点环境灭螺 :江浦县内陆 5 2 5 0 0 m2 ,4个区的江滩 2 0 0 5 1 7m2 和雨花区石驳岸 3 3 3 5 0 m2 ,经一次 (个别环境 2次 )灭螺 ,灭后未查到活螺。江宁区山区1 90 0 0 0 m2 ,灭后 1年钉螺死亡率 95 .4% ,其中 3块 1 60 0 0 m2查不到活螺 ,撒粉后可见植物发黄。结论硼镁石粉灭螺有效剂量 :(1 ) 80 g/ m2 ,4～ 1 1月份撒粉。 (2 )灭光钉螺 2 0 0 g/ m2以上 ,冬春季撒粉。剂量大对植物有毒害     

Magnesium isotope geochemistry in arc volcanism

Incorporation of subducted slab in arc volcanism plays an important role in producing the geochemical and isotopic variations in arc lavas. The mechanism and process by which the slab materials are incorporated, however, are still uncertain. Here, we report, to our knowledge, the first set of Mg isotopic data for a suite of arc lava samples from Martinique Island in the Lesser Antilles arc, which displays one of the most extreme geochemical and isotopic ranges, although the origin of this variability is still highly debated. We find the δ²⁶Mg of the Martinique Island lavas varies from −0.25 to −0.10, in contrast to the narrow range that characterizes the mantle (−0.25 ± 0.04, 2 SD). These high δ²⁶Mg values suggest the incorporation of isotopically heavy Mg from the subducted slab. The large contrast in MgO content between peridotite, basalt, and sediment makes direct mixing between sediment and peridotite, or assimilation by arc crust sediment, unlikely to be the main mechanism to modify Mg isotopes. Instead, the heavy Mg isotopic signature of the Martinique arc lavas requires that the overall composition of the mantle wedge is buffered and modified by the preferential addition of heavy Mg isotopes from fluids released from the altered subducted slab during fluid−mantle interaction. This, in turn, suggests transfer of a large amount of fluid-mobile elements from the subducting slab to the mantle wedge and makes Mg isotopes an excellent tracer of deep fluid migration.Arc volcanism records the elemental cycling between the subducting slab and subarc mantle. Of particular interest is the mechanism by which the subducted material is incorporated into the arc lava. Except for the rare case where arc lava is the direct melting product of a subducted slab (1), most scenarios suggest that mantle wedge is the major magma source that melts after being modified by fluids or melts derived from the subducted basalt and sediment (2, 3). In addition, processes such as polybaric crystallization and crustal assimilation can also modify the composition of arc magmas on their way to the surface. These different processes have different implications on subduction dynamics and elemental cycling, but, in many cases, they are difficult to distinguish. One of the best examples comes from studies of island arc lavas from the Lesser Antilles arc (Fig. 1). Geochemical and Sr, Nd, Pb, Hf, and Li isotopic studies suggest that the Lesser Antilles arc lavas incorporated a variable but to some extent significant amount of subducted sediments (4–8). However, the exact mechanism by which the sediment was incorporated into the lavas is still highly debated and involves various processes such as crustal contamination, subarc mantle metasomatism by fluids released from the slab, or melts derived by partial melting of the subducted sediments (4–17).Open in a separate windowFig. 1.(Upper) Geological map of the Lesser Antilles island arc and the two DSDP sites (sites 144 and 543). (Lower) Comparison of Martinique Island basalts with other Lesser Antilles and worldwide island arcs in ⁸⁷Sr/⁸⁶Sr versus ²⁰⁶Pb/²⁰⁴Pb isotopic space (data compiled by Geochemistry of Rocks of the Oceans and Continents database). Modified from ref. 4 with permission from Elsevier; www.sciencedirect.com/science/journal/0012821X.Magnesium isotopes have the potential to provide new and independent constraints on both source composition and processes operating during the formation of arc magmas, not only because Mg is a major element in all magmas but also because surficial and low-temperature processes fractionate Mg isotopes whereas high-temperature magmatic processes do not (18, 19) (Fig. 2). Subducted marine sediments and altered basalts have isotopic compositions different from those of the normal mantle as sampled by global peridotite xenoliths (Fig. 2); however, they generally have low Mg concentrations (18–25, ^*). In comparison, altered abyssal peridotites have Mg concentrations similar to the normal mantle whereas their Mg isotopic compositions are heavier because of the impact of hydrothermal circulation during accretion and residence in the deep ocean (Fig. 2).^†,‡ Finally, although the mechanism is still not well understood, studies of a few arc peridotites show that they also have slightly heavier Mg isotopic composition than the normal mantle (Fig. 2). Given these observed ranges, Mg isotopes may help in understanding the relative contributions of crustal and mantle components to arc magmatism, but no systematic study of either continental or island arc lavas has been carried out yet.Open in a separate windowFig. 2.Magnesium isotopic composition of Martinique arc lavas and subducting forearc sediments (sites 144 and 543). (Data are reported in ​andS2.)S2.) Data sources for the other reservoirs are from several references (18, 22–24, 36, 42, 43,^*,^†,^‡). The vertical solid line and gray bar represent the average δ²⁶Mg and 2 SD of normal mantle, as sampled by global peridotite xenoliths (−0.25 ± 0.04) (18). The short bold black vertical lines represent the mean δ²⁶Mg value of each individual reservoir.Here, we report Mg isotopic data for 27 arc lavas and 17 subducting forearc sediment samples. The lava samples are from the Martinique Island and cover most of the chemical and isotopic variations in the Lesser Antilles arc (4, 5) (Fig. 1). The sediment samples are from Deep Sea Drilling Project (DSDP) sites 543 and 144 (NE and SE of Martinique Island, respectively); they cover the whole compositional spectrum of subducting sediments and range in lithology from chalky ooze to terrigenous and pelagic deposits (6, 7).The sediments display a large range of δ²⁶Mg (−0.76 to +0.52) with an average of −0.10 ± 0.61 (2 SD) (Fig. 2). This mineralogical control is also evident in studies of loess, shale, mudrock, and carbonates as well as leaching experiments that show preferential enrichment of light Mg isotopes in carbonates over silicates (26, 27).

Table S1.

Magnesium isotopic compositions of standards and subducting sediments from DSDP sites 144 and 543 (SE and NE of Martinique Island, respectively)

参麦注射液合用门冬氨酸钾镁治疗难治性心力衰竭观察

目的：观察参麦注射液与门冬氨酸钾镁注射液合用治疗难治性心力衰竭的疗效。方法：160例充血性心力衰竭（CHF）患者，随机被分为治疗组和对照组。两组基础治疗相同，治疗组加用参麦注射液20ml，门冬氨酸钾镁30ml，5％葡萄糖150ml，每日静脉滴注，连用14d。结果：两组心率、血压、心电图、心功能指标均有改善，但治疗组心率、心功能改善显著（P分别〈0．05，〈0．01），且甚于对照组（P〈0．05）。治疗组的总有效率、心电图疗效优于对照组（P〈0．05），低钾血症和室性心律失常发生率显著少于对照组（P〈0．05）。结论：参麦注射液与门冬氨酸钾镁合用治疗难治性心力衰竭疗效优于常规治疗。     

Comparison of the mineral content of tap water and bottled waters

OBJECTIVES: Because of growing concern that constituents of drinking water may have adverse health effects, consumption of tap water in North America has decreased and consumption of bottled water has increased. Our objectives were to 1) determine whether North American tap water contains clinically important levels of calcium (Ca2+), magnesium (Mg2+), and sodium (Na+) and 2) determine whether differences in mineral content of tap water and commercially available bottled waters are clinically important. DESIGN: We obtained mineral analysis reports from municipal water authorities of 21 major North American cities. Mineral content of tap water was compared with published data regarding commercially available bottled waters and with dietary reference intakes (DRIs). MEASUREMENTS AND MAIN RESULTS: Mineral levels varied among tap water sources in North America and among bottled waters. European bottled waters generally contained higher mineral levels than North American tap water sources and North American bottled waters. For half of the tap water sources we examined, adults may fulfill between 8% and 16% of their Ca2+ DRI and between 6% and 31% of their Mg2+ DRI by drinking 2 liters per day. One liter of most moderate mineralization European bottled waters contained between 20% and 58% of the Ca2+ DRI and between 16% and 41% of the Mg2+ DRI in adults. High mineralization bottled waters often contained up to half of the maximum recommended daily intake of Na+. CONCLUSION: Drinking water sources available to North Americans may contain high levels of Ca2+, Mg2+, and Na+ and may provide clinically important portions of the recommended dietary intake of these minerals. Physicians should encourage patients to check the mineral content of their drinking water, whether tap or bottled, and choose water most appropriate for their needs.