Changes in cyclic nucleotides during the calcium paradox in the isolated rat heart

Reperfusion of hearts with a Ca²⁺-containing medium after a perfusion period in Ca²⁺-free medium results in irreversible cell damage (calcium paradox). In this investigation we have studied coronary flow and cyclic AMP and cyclic GMP levels after several periods of Ca²⁺-free perfusion in isolated rat hearts. We also investigated the effects of papaverine (Pap), noradrenaline (NA), acetylcholine (ACh) and absence of inorganic phosphate during Ca²⁺-free perfusion on coronary flow (CF) and cyclic nucleotide levels. Inability of the heart to recover contractile activity with development of contracture during the reperfusion period was accepted as indicative of the calcium paradox. Ca²⁺-free perfusion alone and NA and absence of inorganic phosphate during the Ca²⁺-free perfusion period increased CF, whereas Pap and ACh decreased it. However, only Ca²⁺-free perfusion and NA elevated cyclic AMP. On the other hand, Pap and ACh increased cyclic GMP (with a transient rise of cyclic AMP in Pap infusion), and absence of inorganic phosphate decreased both cyclic AMP and cyclic GMP. Pap, ACh and absence of phosphate prevented the calcium paradox. Our study suggests that increased cyclic AMP during the Ca²⁺-free perfusion may contribute, with the other factors, to the occurrence of the calcium paradox.     

高效液相色谱-电感耦合等离子体质谱法测定海鱼中无机砷

目的建立测定海鱼中无机砷含量的高效液相色谱-电感耦合等离子体质谱法。方法海鱼样品经稀硝酸超声热水浴提取后,AS7阴离子交换色谱柱分离,3.5 mmol/L(NH4)2CO3+1%甲醇与100 mmol/L(NH4)2CO3+1%甲醇流动相梯度洗脱,电感耦合等离子体质谱仪测定,以保留时间定性,外标法定量。结果在1~100μg/L的线性范围,6种砷形态化合物的回归方程均呈良好的线性关系,相关系数均优于0.9996,检出限为0.05~0.25μg/L,定量限为0.17~0.84μg/L,3个浓度加标回收率为88.5%~106.4%,相对标准偏差为2.5%~4.9%。结论本方法满足海鱼中无机砷含量的测定要求,提取快速,稳定,操作简单,检出限低,方法的重现性好,灵敏度高。     

蒙药毛勒日—达布斯—4汤中微量元素及氨基酸含量的测定

目的：测定蒙药毛勒日-达布斯-4汤中微量元素和氨基酸的含量。方法：用原子吸收分光光度计,测定蒙药毛勒日-达布斯-4汤中几种重要的微量元素含量;用氨基酸自动分析仪测定氨基酸的含量。结果与结论：蒙药毛勒日-达布斯-4汤中含有较高的Mn、Fe、Zn和Mg;含有17种氨基酸,包括7种人体必需氨基酸,氨基酸总量为4.615%（mg/g）。     

大鼠磨牙三维有限元模型的建立

目的 :建立大鼠磨牙的三维有限元模型 ,探讨牙及牙周组织的应力分布状况。方法 :采用Sprague Dawley大鼠 2 0只 ,建立大鼠磨牙正畸移动的动物模型 ,制作大鼠上颌第一磨牙牙周连续切片 ;采用计算机技术 ,重建牙及牙周组织三维形态、结构 ,并建立其三维有限元模型。结果 :组织切片的应力分布显示牙周膜是一种存在于两种硬组织之间的软组织 ,有其特有的应力分布状态。结论 :本研究建立的正畸大鼠磨牙三维有限元模型是观察正畸牙移动过程中分析应力的一种简便、准确、可靠的模型及方法。     

冬凌草水溶性成分及氨基酸、无机元素的测定

目的 :分离冬凌草中的水溶性成分和测定某些无机元素和氨基酸的含量。方法 :对冬凌草进行柱层析分离水溶性成分 ;用原子吸收分光光度法测定无机元素含量 ;用氨基酸自动分析法测定氨基酸含量。结果 :冬凌草中的水溶性成分确定为葡萄糖 ;无机元素锌、铜、钙、镁质量分数分别为 0 0 32 ,0 0 0 2 ,16 43和 12 0 3mg·g-1;含 18种氨基酸 ,其总质量分数为 7 45 %。结论 :冬凌草含有水溶性成分单糖 ,含有多种氨基酸 ,而所含无机元素中以钙含量较高。     

微量元素在4-硝基喹啉氧化物诱发口腔腭粘膜癌变中的变化及意义(英文)

目的 :研究 4 硝基喹啉氧化物 (4 nitroquinoline 1 oxide ,4NQO)诱发大鼠腭粘膜上皮细胞癌变过程中细胞内微量元素的变化及意义。方法 :将 4NQO涂于 2 8只Wistar大鼠硬腭后部粘膜 ,每周三次 ,共 19周。不同时期的所有粘膜标本被病理学分别证实为正常粘膜 ,癌前病变及鳞状上皮细胞癌 ,并进行电子探针显微分析。结果 :鳞状上皮细胞癌核及胞浆内铜 (Cu) ,锌 (Zn)明显下降 (P <0 .0 5 )。癌前病变上皮细胞浆内钼明显减少 (P <0 .0 1) ,而鳞癌细胞胞浆内Mo明显升高。癌变过程中 ,细胞内Se无明显变化。同时 ,鳞癌细胞Cu/Zn升高 ;Cu/Se ,Zn/Se降低。结论 :细胞内Cu ,Zn ,Mo的改变与口腔癌变有明显关联。     

良性前列腺增生症与前列腺癌患者及健康者头发中5种微量元素的测定

用原子吸收光谱法测定良性前列腺增生 (BPH)和前列腺癌 (PCa)患者及健康者头发中铜、锌、铁、锰和镉5种元素的含量。结果表明 :PCa患者发锌含量较健康者及BPH显著减少 (P <0 .0 1) ,而其他 4种微量元素在三组间差异无显著性 (P >0 .0 5 )。发锌含量的显著降低 ,可能为早期前列腺癌的诊断提供重要线索     

A trace element preparation increases antitumor activity in mice

A trace element preparation (Béres Drops Plus, BDP) produced immunomodulatory effects in previous in vitro and in vivo experiments. Here, C57B1/6 inbred mice were transplanted with either Lewis lung tumor or with B16 melanoma. BDP was given intraperitoneally a. before transplantation; b. after transplantation or c. after the removal of the primary tumor. As a result, BDP pretreatment could slow down the tumor progression by decreasing the number and the volume of metastases as well as the proportion of mice with metastases without influencing the growth of the primary tumors. Furthermore, BDP treatment improved the immunological activity of the tumor-bearing host, too. These preliminary data suggest that the parenteral administration of the practically non-toxic BDP could help to control tumor progression in experimental models.     

小儿肾小球疾病血清微量元素测定与分析

采用原子吸收分光光度法,测定了７８ 例肾小球疾病患儿血清铜、锌、铁、镁４ 种元素。结果显示,单纯性肾病组、肾炎性肾病组、紫癜性肾病组及肾炎组血清锌均显著低于正常组（ Ｐ＜ ００５）,血清铁、镁与正常组比较无显著差异。单纯性肾病组,肾炎性肾病组血清铜显著低于正常组（ Ｐ＜ ００５）。提示血清铜、锌、铁、镁含量的变化与疾病发生和疾病状态有关。     

微量元素在化妆品中的应用

本文对七种常应用于化妆品中的微量元素的功能、作用机理、研究现状作了较为详细的讨论。