2010-2012年大连市游泳池水水质卫生状况监测结果分析

目的了解大连市泳池水的水质卫生状况及变化趋势,为进一步提高泳池水的卫生质量,预防感染性疾病暴发。方法按照GB／T18204—2000《公共场所卫生标准检验方法》对大连市泳池水中的尿素、细菌总数、大肠菌群进行检验;按照GB／T5750-2006（（生活饮用水标准检验方法》进行游离性余氯的检验。结果近3a合计检测403份水样,合格的287份,合格率为71．22％;各年的合格率分别为63．95％、69．94％、84．95％,不同年份间合格率的差异有统计学意义（X^2=12．473,P〈0．01）。近3a总项目的样品份数为1612份,合格份数1464份,合格率为90．80％;不同项目游离性余氯尿素、细菌总数、大肠菌群合格率的差异有统计学意义（X^2=170．44,P〈0．01）。结论大连市游泳池水水质卫生状况逐年趋好,但还是不容忽视,今后应加强卫生监督监测管理工作,加强对管理者的卫生管理意识,进一步提高泳池水的卫生质量,保障游泳者的身体健康。     

Intracellular Ca antagonist TMB-8 blocks catecholamine secretion evoked by caffeine and acetylcholine from perfused cat adrenal glands in the absence of extracellular Ca

Unlike acetylcholine, caffeine was much more effective in releasing catecholamine in the absence of extracellular Ca²⁺ than in its presence in perfused cat adrenal glands. The intracellular Ca²⁺ antagonist, TMB-8 (10⁻⁴ M), inhibited reversibly the catecholamine secretion evoked by caffeine (40 mM) and that induced by acetylcholine (10⁻⁴ M) in the presence of hexamethonium (10⁻³ M) during perfusion with Ca²⁺-free Locke solution containing EGTA (10⁻⁵ M). These results support our view that muscarinic receptor activation causes catecholamine secretion by mobilizing Ca²⁺ from an intracellular pool just as caffeine does.     

营养素防护同型半胱氨酸致ECV304细胞损伤和凋亡

目的: 探讨叶酸、维生素E(VE)和硒(Se)对同型半胱氨酸(homocysteine, Hcy)诱导ECV304细胞损伤和凋亡的防护作用及其机制。方法: 采用倒置显微镜观察和MTT实验检测各种营养素对Hcy细胞损伤作用的防护,采用琼脂糖凝胶DNA电泳和流式细胞仪检测各种营养素对Hcy诱导细胞凋亡作用的防护。并通过测定细胞内脂质过氧化水平、细胞内抗氧化酶活力及对细胞内活性氧产生的改变研究其保护机制。结果: 叶酸、VE和Se都可防护Hcy的细胞增殖抑制和诱导细胞凋亡作用,并都可明显减少细胞内MDA含量。叶酸可以明显增加细胞内SOD活力,叶酸和Se可以明显增加细胞内GSH-Px活力。VE对Hcy诱导的细胞内活性氧产生具有明显抑制作用,而Se和叶酸抑制作用不明显。结论: 叶酸、VE和Se都可以防护Hcy导致的细胞增殖抑制,并可以抑制Hcy诱导的细胞凋亡,但其作用机制不同。     

锌代谢池—判断人体锌营养状况的可靠指标

用稳定性同位素锌(~(68)Zn和~(70)Zn)对2例志愿者进行了历时15周不同锌营养水平的代谢实验。结果表明,锌代谢池能正确地反映人体的锌营养状况。空腹和餐后血浆锌浓度的差别比单独测定空腹血浆锌浓度更为可靠。每日尿锌和粪锌的排泄量则有一定的局限性。粪便中内源性锌排泄量的测定对确定人体每日锌的供给量标准,具有一定的参考价值。     

运动负荷后早期门控心肌显像对冠心病严重三支病变的诊断价值

目的比较运动负荷早期(15～20min)^99Tc^m-甲氧基异丁基异腈(MIBI)门控心肌显像(G-MPI)和非门控心肌显像(NG-MPI)诊断冠心病(CAD)严重三支病变(狭窄≥70％)的价值。方法以冠状动脉(简称冠脉)造影(CAG)所示冠脉直径狭窄≥70％为严重CAD诊断标准，将同期做运动负荷^99Tc^m-MIBI SPECT G-MPI和CAG的215例患者分为CAD三支病变组(A组)与CAD非三支病变组(B组)。结果G-MPI与NG-MPI诊断严重CAD的灵敏度分别为95．3％(143／150例)和90．7％(136／150例，X^2=2．509，P=0．113)，特异性分别为80．0％(52／65例)和72．3％(47／65例，X^2=1．059，P=0．303)；诊断CAD三支病变的灵敏度分别为100％(51／51例)和92．2％(47／51例)，前者更好，且两者差异有显著性(X^2=4．163，P=0．041)。结论在诊断临床高危CAD严重三支病变时，G-MPI比NGMPI更有价值。     

回肠Ｎａ+/胆汁酸转运体抑制剂SC-435对豚鼠胃肠移行性复合波的作用

目的：研究回肠Na+/胆酸转运体( IBAT)抑制剂SC-435喂养后，豚鼠胃肠移行性复合波(MMC)与胆酸池大小的变化。方法：60只豚鼠分别给予正常饮食和IBAT抑制剂SC-435饮食2周、4周、8周。喂养结束后，评估胆囊动力并将4对电极植入胃窦、12指肠、空肠、回肠。7d后，记录MMC并测量胆酸池大小。结果：IBAT抑制剂喂养后，胆囊动力在4周与8周组下降。胆酸池在4周组减小17.11% (P<0.05)，8周组减小48.35%(P<0.05)。MMC起源部位发生改变：胃窦起源(37%)和十二指肠起源(46%)减少而空肠起源(17%)增多。与对照组相比，MMC周期延长(4周组1.16倍,P<0.05; 8周组1.38倍,P<0.05)而波幅降低 (4周组降低10.58%,P<0.05; 8周组降低49.17 %,P<0.05)。在对照组与2周组之间，所有MMC参数无统计学意义差异。结论：IBAT抑制剂 SC-435减小胆酸池并抑制MMC运动； MMC与胆酸肠肝循环有关，与胆酸池大小改变一致。     

The combination of α-lipoic acid supplementation and aerobic exercise inhibits lipid peroxidation in rat skeletal muscles

We investigated the effect of dl-α-lipoic acid (LA) supplementation and regular aerobic exercise on the concentrations of malondialdehyde (MDA) and vitamin E, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and the levels of glutathione (GSH) in rat skeletal muscles (soleus and red gastrocnemius). For 8 weeks, rats (n = 7 per group) were (1) exercised on a treadmill for 30 min d⁻¹, (2) treated with supplemental LA, or (3) exercised and treated with supplemental LA. Control rats (n = 7) did not receive LA and were not exercised. dl-α-Lipoic acid (100 mg kg⁻¹) was administered daily as an oral supplement. The rats were exercised in a graded manner for 5 d wk⁻¹. The concentration of MDA in the soleus and red gastrocnemius was significantly lower in rats that exercised and received LA than in the other groups. Compared with the other groups, rats that exercised and received LA had a significantly higher vitamin E concentration in the soleus. The SOD and GPx activities in the soleus and red gastrocnemius were significantly higher in rats that exercised and received LA. These results suggest that LA supplementation combined with aerobic treadmill exercise inhibits lipid peroxidation in skeletal muscles. This effect was especially remarkable in the soleus, which is particularly sensitive to oxidative stress, as revealed by the increased vitamin E level and SOD and GPx activities.     

Streptozotocin induced activation of oxidative stress responsive splenic cell signaling pathways: Protective role of arjunolic acid

Present study investigates the beneficial role of arjunolic acid (AA) against the alteration in the cytokine levels and simultaneous activation of oxidative stress responsive signaling pathways in spleen under hyperglycemic condition. Diabetes was induced by injection of streptozotocin (STZ) (at a dose of 70 mg/kg body weight, injected in the tail vain). STZ administration elevated the levels of IL-2 as well as IFN-γ and attenuated the level of TNF-α in the sera of diabetic animals. In addition, hyperglycemia is also associated with the increased production of intracellular reactive intermediates resulting with the elevation in lipid peroxidation, protein carbonylation and reduction in intracellular antioxidant defense. Investigating the oxidative stress responsive cell signaling pathways, increased expressions (immunoreactive concentrations) of phosphorylated p65 as well as its inhibitor protein phospho IκBα and phosphorylated mitogen activated protein kinases (MAPKs) have been observed in diabetic spleen tissue. Studies on isolated splenocytes revealed that hyperglycemia caused disruption of mitochondrial membrane potential, elevation in the concentration of cytosolic cytochrome c as well as activation of caspase 3 leading to apoptotic cell death. Histological examination revealed that diabetic induction depleted the white pulp scoring which is in agreement with the reduced immunological response. Treatment with AA prevented the hyperglycemia and its associated pathogenesis in spleen tissue. Results suggest that AA might act as an anti-diabetic and immunomodulatory agent against hyperglycemia.     

Testing the three-pool white matter model adapted for use with T2 relaxometry.

A three-pool model was used to improve white-matter T2 relaxometry in low signal-to-noise (SNR) data. To verify the model very high SNR T2 relaxometry experiments were performed on myelinated tissue samples and three-pool fractions were consistently found. Relaxation curves based on the in vitro results were simulated with multiple SNRs and fit using the three-pool model and three less constraining nonnegative least squares-based methods. All methods performed well with noiseless data. At lower SNR values the three-pool model was superior, primarily due to the fact that the other methods often could not unambiguously calculate pool fractions.