芍药苷对D-半乳糖和亚硝酸钠诱导的小鼠认知障碍与神经元变性的改善作用

目的:探讨芍药苷(PF)对D-半乳糖(D-gal)和亚硝酸钠(NaNO2)诱导的衰老小鼠认知障碍与神经元凋亡的改善作用.方法:皮下注射D-gal和NaNO2制备小鼠衰老模型.使用Morris水迷宫检测小鼠空间记忆能力.取小鼠脑组织检测丙二醛(MDA)水平、总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化酶(GSH-Px)活性.经H&E、TUNEL染色和caspase-3免疫组化染色观察海马神经元损伤、凋亡和caspase-3表达变化.结果:D-gal和NaNO2可诱导小鼠认知功能衰退,海马神经元损伤.给予PF可改善模型鼠认知障碍和海马神经元损伤,减少caspase-3在海马的表达,提高降低的T-SOD、GSH-Px活性,减少升高的MDA含量.结论:PF通过抑制氧化损伤途径改善D-gal和NaNO2诱导的小鼠认知障碍与海马神经元变性.     

双波长紫外分光光度法同时测定戊二醛消毒液中戊二醛和亚硝酸钠的含量

目的建立双波长紫外分光光度法同时测定戊二醛消毒液中戊二醛和亚硝酸钠含量的方法。方法在波长281nm和381．5nm处直接测定戊二醛消毒液的吸收度。结果在波长281nm处,戊二醛含量和吸收度具有良好的相关性,C=0．02413＋1．3825A（r=0．9998）,线性范围为0．49％～2．96％．平均加样回收率为99．94％;在波长381．5nm处。亚硝酸钠含量和吸收度具有良好的相关性,A=0．01387＋1．2062C（r=0．9999）,线性范围为0．1035％～0．8280％,平均加样回收率为99．85％。结论该方法简便、准确,操作简单。可用于戊二醛消毒液的含量测定。     

Nerve-induced release of nitric oxide in the rabbit gastrointestinal tract as measured by in vivo microdialysis

1. Nitric oxide (NO) has been suggested as a gastrointestinal neurotransmitter, mediating the gastric receptive relaxation and the relaxation in the peristaltic reflex. The aim of the present study was to measure nerve-induced NO formation in vivo in the gastrointestinal tract.
2. Formation of the nitric oxide oxidation products nitrite and nitrate during vagal nerve stimulation were measured in the anaesthetized rabbit. Microdialysis probes were inserted into the wall of the stomach and proximal colon, and nitrite and nitrate in dialysate measured by capillary electrophoresis.
3. During bilateral vagal nerve stimulation there was an increase in nitrite and nitrate formation at the level of the stomach and in nitrite formation at the level of the colon. This increase was inhibited by intravenous administration of the NO synthase inhibitor N^ω-nitro-L-arginine methyl ester (L-NAME 30 mg kg⁻¹). Furthermore, L-NAME significantly increased nerve-induced gastric and colonic contractions, as well as spontaneous colonic contractions.
4. In summary, we present a new methodological procedure for quantification of small changes in nitric oxide formation in vivo. This study provides evidence that nitric oxide is released in the stomach and colonic wall during vagal nerve activity, at concentrations able to cause inhibition of smooth muscle contractions in vivo.

     

蔬菜中的硝酸盐、亚硝酸盐的气相色谱法测定

目的：利用选择性强的电子捕获检测器测定蔬菜中的硝酸盐和亚硝酸盐。方法：样品中硝酸根用硫酸作催化剂,温度控制在90℃以下时可与苯发生反应生成硝基苯,萃取,然后利用选择性强的电子捕获检测器检测。结果：样品加标回收率硝酸盐的回收率在79.72%～101.79%之间,亚硝酸盐的回收率在88.06%～105.81%;变异系数3.22～5.93,硝酸盐最低检出浓度为0.75 mg/kg）;亚硝酸盐的最低检测浓度为0.609 mg/kg。结论：该法的样品处理与经典的国标法比较取样量少、简单快速,避免了其他离子的干扰,提高了灵敏度和准确度,操作简便易性行。一机多用。     

离子色谱法测定瓶(桶)装水中痕量亚硝酸盐

[目的]采用离子色谱法测定水中痕量亚硝酸盐的含量.[方法]色谱柱为DIONEX Ionpac AS19-2mm, KOH为淋洗液,梯度淋洗,流速为0.3ml/min,抑制电流:34mA,电导检测.[结果]瓶(桶)装饮用水中的痕量亚硝酸盐测定,最低检测浓度(定量下限)为1.00μg/L,回收率在98.5%-112.0%之间.[结论]本法能满足μg/L级的定量分析要求,测定方法简便、准确、实用性强.     

对二甲氨基酚,依地酸二钴和亚硝酸钠对犬心脏血流动力学的影响

本文观察了DMAP,Co_2 EDTA和NaNO_2对犬心脏血流动力学的影响。iv DMAP 3.2mg/kg后LVP及其±dP/dtmax短暂轻度增加,CI,MAP,TPVR,LVWI和HR在30 min内基本稳定,至60 min时CI,LVWI和-dp/dtmax下降。iv Co_2EDTA 15mg/kg或NaNO_2 20 mg/kg后10 min MAP,CI,LVWI,LVP,±dP/dtmax及TPVR(Co_2EDTA组除外)降低最明显,60 min时NaNO_2组CI,MAP,TPVR,LVP和LVWI及Co+2EDTA组CI和LVWI仍然下降。Co_2EDTA组TPVR 1min时下降,5 min见恢复,60min上升。表明(1)DMAP能维持血压和外周血管张力平稳,使心脏舒缩性能短暂轻度增强;(2)Co_2EDTA初期降压系由其扩张血管和抑制心功能所致,后期降压主要由后者引起;(3)NaNO_2降压作用系通过扩张外周血管和抑制心功能所致。     

林县冬贮菜中亚硝酸盐及维生素C的含量分析

对林县食管癌高发区两种冬贮菜中亚硝酸盐和维生素C的动态分析,表明亚硝酸盐含量随蔬菜冬贮时间延长而增加,维生素C含量则逐渐降低,两者成负相关。提示蔬菜冬贮过程中应尽量减少维生素C的破坏。     

亚硝酸盐法测定超氧化物歧化酶活性

用亚硝酸盐、氰化钾抑制区别法测定样品中的 Cu,Zn-SOD 和 Mn-SOD,灵敏度高,重现性好,操作简便。实验表明,抑制率达50%时所需 SOD 的浓度为0.07 μg/ml,其批内和批间的变异系数分别为6.0%和5.5%,鸡肝 Cu,Zn-SOD 与 KCN 的抑制复合物的表观解离常数 K′为288.6±45.5 μmol。     

New treatment of free-radical scavenger in adrenoleukodystrophy

What is known and Objective: Adrenoleukodystrophy (ALD) is an X‐linked disorder and characterized by the accumulation of saturated very long‐chain fatty acids. Treatment is still unsatisfactory. Our objective is to report on the effect of the free‐radical scavenger, edaravone, in a patient with ALD. Case summary: The patient was given edaravone intravenously twice. D‐ROM in cerebral spinal fluid decreased dramatically, and a shortening of neuronal transmission time as estimated on somatosensory evoked potential was observed. After terminating the treatment, his symptoms progressively reappeared. What is new and Conclusion: This is the first report of the use of edaravone in ALD. The drug is apparently effective in improving symptoms of ALD and should be evaluated more formally.