Sysmex XT-2000i血液细胞分析仪在临床检验的应用

目的优选醉鱼草果实总三萜的最佳提取工艺。方法以醉鱼草果实总三萜提取率及浸膏得率为考察指标,采用正交试验,对乙醇浓度(A)、提取时间(B)、提取次数(C)、料液比(D)4个因素进行考察,筛选出最佳提取工艺。结果优选出最佳提取工艺为80%乙醇,料液比1∶10,回流提取3次,每次1 h。结论优选的提取方法适于醉鱼草果实总三萜的提取。     

紫外分光光度法测定醉鱼草果实中总黄酮含量

目的：建立醉鱼草果实中总黄酮的含量测定方法。方法采用紫外分光光度法,以芦丁为对照品,通过亚硝酸钠－硝酸铝－氢氧化钠系统显色法测定醉鱼草果实中总黄酮的含量。结果芦丁在8．56～51．36 mg· L－1范围内吸光度与浓度呈良好的线性关系（A＝0．0120 C－0．0071,r＝0．9998）,平均加样回收率为98．76％,相对标准偏差为1．74％（n＝6）,所测得醉鱼草果实中总黄酮含量为5．29％。结论该方法操作快速、简便,结果准确可靠,可用于醉鱼草果实中总黄酮成分的含量测定。     

Two new compounds from the fruits of Buddleja lindleyana with neuroprotective effect

Two new triterpenoid glycosides, mimengosides H (1) and I (2), were isolated from the fruits of Buddleja lindleyana Fort. Their structures were determined by extensive spectroscopic methods. Neuroprotective effects of these isolates against 1-methyl-4-phenylpyridinium ion-induced neurotoxicity in PC12 cells were evaluated. Pretreatment with compound 1 had potential protective effect in a concentration range from 0.1 to 1 μmol l?1.     

A comparison of neuroprotective efficacy of two novel reactivators of acetylcholinesterase called K920 and K923 with the oxime K203 and trimedoxime in tabun-poisoned rats

The ability of two newly developed bispyridinium oximes (K920, K923) to reduce tabun-induced acute neurotoxic signs and symptoms was compared with the oxime K203 and trimedoxime using a functional observational battery (FOB). The neuroprotective effects of the oximes studied combined with atropine on rats poisoned with tabun at a sublethal dose (130?μg/kg i.m.; 80% of LD₅₀ value) were evaluated. Tabun-induced neurotoxicity was monitored by FOB at 2?h after tabun administration. The results indicate that all tested oximes combined with atropine enable tabun-poisoned rats to survive till the end of experiment while one non-treated tabun-poisoned rat died within 2?h. Both newly developed oximes (K920, K923) combined with atropine were able to markedly decrease tabun-induced neurotoxicity in the case of sublethal poisoning although they did not eliminate all tabun-induced acute neurotoxic signs and symptoms. Their ability to decrease tabun-induced acute neurotoxicity did not prevail the neuroprotective efficacy of trimedoxime and the oxime K203. Therefore, the newly developed oximes are not suitable for the replacement of currently available oximes (especially trimedoxime) in the treatment of acute tabun poisonings.     

Three new sulfated triterpenoids from the roots of Gypsophila pacifica

Three new sulfated triterpenoids (1–3), along with one known compound (4), were isolated from the roots of Gypsophila pacifica Kom. The structures of the new compounds were established as 3β-O-sulfate gypsogenin 28-O-β-d-glucopyranosyl ester (1), 3β-O-sulfate gypsogenin (2), and 3β-O-sulfate quillaic acid (3) on the basis of 1D, 2D NMR, and HR-ESI-MS methods.     

Three lanostane triterpenoids from the fruiting bodies of Stropharia aeruginosa

Three new lanostane triterpenoids, aeruginosic acid derivatives, were isolated from the fruiting bodies of Stropharia aeruginosa and their structures were determined on the basis of spectral data.     

Three lanostane triterpenoids from the fruiting bodies of Stropharia aeruginosa

Three new lanostane triterpenoids, aeruginosic acid derivatives, were isolated from the fruiting bodies of Stropharia aeruginosa and their structures were determined on the basis of spectral data.     

Highly oxygenated triterpenoids from the roots of Schisandra chinensis and their anti-inflammatory activities

A new highly oxygenated triterpenoid, schinchinenlactone D (1), and three known compounds (2–4) were isolated from the roots of Schisandra chinensis. Their structures were determined by combining the spectroscopic analysis with the theoretical computations. The anti-inflammatory activities of compounds 1–4 were evaluated, and compound 3 exhibits the most significant activity in the inhibition of NO production with an IC₅₀ value of 10.6 μM.     

Three lanostane triterpenoids,aeruginosols A,B and C,from the fruiting bodies of Stropharia aeruginosa

Phytochemical analysis of the MeOH extract of the fruiting bodies of Stropharia aeruginosa resulted in the isolation of three lanostane triterpenoids, aeruginosols A, B and C. The structures of the new compounds were determined by spectroscopic analysis. The biological activities of aeruginosols A, B and C were examined by bioassay with lettuce seedling.     

Three lanostane triterpenoids, aeruginosols A, B and C, from the fruiting bodies of Stropharia aeruginosa

Phytochemical analysis of the MeOH extract of the fruiting bodies of Stropharia aeruginosa resulted in the isolation of three lanostane triterpenoids, aeruginosols A, B and C. The structures of the new compounds were determined by spectroscopic analysis. The biological activities of aeruginosols A, B and C were examined by bioassay with lettuce seedling.     

ATP敏感性钾通道的阻断剂与开放剂研究进展

ATP敏感性钾通道是高血压、心绞痛、糖尿病及缺血性脑损伤等多种疾病的治疗靶点之一。通过对调节KATP通道药物的选择性、可逆性、作用位点以及相互调节的研究，可以对一些临床用药进行重新评估，并指导开发高选择性的KATP通道阻断剂和开放剂。     

Effects of glutamate transport substrates and glutamate receptor ligands on the activity of Na-/K(+)-ATPase in brain tissue in vitro

1. It has been suggested that Na+/K(+)-ATPase and Na(+)-dependent glutamate transport (GluT) are tightly linked in brain tissue. In the present study, we have investigated Na+/K(+)-ATPase activity using Rb+ uptake by 'minislices' (prisms) of the cerebral cortex. This preparation preserves the morphology of neurons, synapses and astrocytes and is known to possess potent GluT that has been well characterized. Uptake of Rb+ was determined by estimating Rb+ in aqueous extracts of the minislices, using atomic absorption spectroscopy. 2. We determined the potencies of several known substrates/inhibitors of GluT, such as L-trans-pyrrolidine-2,4-dicarboxylate (LtPDC), DL-threo-3-benzyloxyaspartic acid, (2S,3S,4R)-2-(carboxycyclopropyl)-glycine (L-CCG III) and L-anti,endo-3,4-methanopyrrolidine dicarboxylic acid, as inhibitors of [3H]-L-glutamate uptake by cortical prisms. In addition, we established the susceptibility of GluT, measured as [3H]-L-glutamate uptake in brain cortical prisms, to the inhibition of Na+/K(+)-ATPase by ouabain. Then, we tested the hypothesis that the Na+/K(+)-ATPase (measured as Rb+ uptake) can respond to changes in the activity of GluT produced by using GluT substrates as GluT-specific pharmacological tools. 3. The Na+/K(+)-ATPase inhibitor ouabain completely blocked Rb+ uptake (IC50 = 17 micromol/L), but it also potently inhibited a fraction of GluT (approximately 50% of [3H]-L-glutamate uptake was eliminated; IC50 < 1 micromol/L). 4. None of the most commonly used GluT substrates and inhibitors, such as L-aspartate, D-aspartate, L-CCG III and LtPDC (all at 500 micromol/L), produced any significant changes in Rb+ uptake. 5. The N-methyl-D-aspartate (NMDA) receptor agonists (R,S)-(tetrazol-5-yl)-glycine and NMDA decreased Rb+ uptake in a manner compatible with their known neurotoxic actions. 6. None of the agonists or antagonists for any of the other major classes of glutamate receptors caused significant changes in Rb+ uptake. 7. We conclude that, even if a subpopulation of glutamate transporters in the rat cerebral cortex may be intimately linked to a fraction of Na+/K(+)-ATPase, it is not possible, under the present experimental conditions, to detect regulation of Na+/K(+)-ATPase by GluT.     

Selaginellins I and J,two new alkynyl phenols,from Selaginella tamariscina (Beauv.) Spring

Selaginellins I (1) and J (2), two new compounds, were isolated from Selaginella tamariscina (Beauv.) Spring and were characterized as (R,S)-4-((2′,4′-dihydroxy-4-(hydroxymethyl)-3-((4-hydroxyphenyl)ethynyl)biphenyl-2-yl)(4-hydroxyphenyl)methylene)cyclohexa-2,5-dienone (1) and (R,S)-4-((3-((3,4-dihydroxyphenyl)ethynyl)-4′-hydroxy-4-(hydroxymethyl)biphenyl-2-yl)(4-hydroxyphenyl)methylene)cyclohexa-2,5-dienone (2) on the basis of UV, IR, 1D and 2D NMR, and HR-ESI-MS spectroscopic analysis.     

Interaction between theophylline and ouabain in the rabbit heart: Effect on (Na + K)-ATPase

In electrically stimulated rabbit ventricular strips, theophylline (0.3–30 M) antagonized the increased contractility produced by ouabain (0.8 μM). Initial velocity of specific [³H]ouabain binding to homogenates prepared from the muscle strips was used to determine the fraction of binding sites occupied by ouabain. Theophylline decreased the binding of ouabain to (Na⁺ + K⁺)-ATPase. It is concluded that the effect of theophylline on ouabain-induced positive inotropism may be mediated by decreased ouabain binding to (Na⁺ + K⁺)-ATPase.     

Inhibition by digoxin and SC4453 of (Na + K)-ATPase prepared from human heart, guinea-pig heart and guinea-pig brain

SC4453 is a digoxin analogue with a pyridazine instead of a lactone ring on C_17β. SC4453 was compared with digoxin with respect to inhibition of (Na⁺ + K⁺)-ATPase prepared from human heart, guinea-pig heart and guinea-pig brain. SC4453 was slightly less potent than digoxin but showed a similar sensitivity to K⁺. As for cardenolides, species differences in sensitivity to SC4453 were accounted for by differences in the rate of dissociation from the receptors. These observations confirm that the human heart is one of the tissues most sensitive to cardiac glycosides.     

Effects of gallopamil, diltiazem and nifedipine on the loss of K from ischaemic pig hearts

K⁺ release into the extracellular space was investigated during repeated 6-min coronary occlusions before and after the intravenous administration of cardiovascular active doses of gallopamil (0.02; 0.05 mg/kg), diltiazem (1.0; 2.0 mg/kg) or nifedifine (0.01; 0.05 mg/kg) to anaesthetized pigs. [K⁺]_e was measured epicardially using silver valinomycin electrodes calibrated in vivo. During control occlusions [K⁺]_e rose steeply in all groups, from a pre-ischaemic baseline value of about 3.5 mmol/1 reaching a plateau value within the ischaemic period. This response was reproducible in an untreated control group. Gallopamil reduced the ischaemic K⁺ efflux dose dependently and significantly 10 min after injection; the higher dose also did 60 min after injection. Diltiazem had less effect on K⁺ efflux 10 min after administration and an effect was no longer detectable after 60 min. Nifedipine did not significantly inhibit the ischaemic K⁺ loss. Besides these differences in the direct protection of the ischaemic myocardium, the Ca²⁺ antagonists also had the following effects on the haemodynamic profile. Diltiazem and gallopamil significantly prolonged PQ intervals whereas nifedipine caused a shortening accompanied by a significant increase in heart rate. Blood pressure and LV dP/dt_max were significantly reduced by all compounds, but to a different degree. Diltiazem reduced blood pressure to a greater extent than did nifedipine and gallopamil. LV dP/dt_max was comparably reduced by gallopamil and diltiazem, while nifedipine had less effect. Thus, gallopamil exerted pronounced protective effects on the ischaemic pig heart.     

A comparison of the potency of newly developed oximes (K027, K048) and commonly used oximes (obidoxime, HI-6) to counteract tabun-induced neurotoxicity in rats

The neuroprotective effects of newly developed oximes (K027, K048) and currently available oximes (obidoxime, HI-6) in combination with atropine in rats poisoned with tabun at a sublethal dose (170 microg kg(-1) i.m.; 80% of LD(50) value) were studied. The tabun-induced neurotoxicity was monitored using a functional observational battery and an automatic measurement of motor activity. The neurotoxicity of tabun was monitored at 24 h and 7 days following tabun challenge. The results indicate that the oxime HI-6 in combination with atropine was not able to protect the rats from the lethal effects of tabun. Two non-treated tabun-poisoned rats and one tabun-poisoned rat treated with atropine combined with HI-6 died within 2 h. On the other hand, all other tested oximes combined with atropine allowed all the tabun-poisoned rats to survive 7 days following tabun challenge. Both newly developed oximes combined with atropine seem to be sufficiently effective antidotes for a decrease in tabun-induced neurotoxicity in the case of sublethal poisoning although they are not able to eliminate tabun-induced neurotoxicity completely. The neuroprotective efficacy of obidoxime in combination with atropine approached the potency of newly developed oximes but the ability of the oxime HI-6 to counteract tabun-induced acute neurotoxicity was significantly lower, especially at 24 h after tabun poisoning. Due to their neuroprotective effects, both newly developed oximes appear to be suitable oximes for the antidotal treatment of acute tabun poisoning.     

Two new triterpenoids from the leaves and stems of Fritillaria hupehensis

Two new cycloartane-type triterpenoids 25-hydroxyl-9,19-cycloart-22-ene-3-one (1) and (23Z)-9,19-cycloart-23-ene-3α,25-diol (2) along with 9,19-cycloart-25-ene-3β, 24ξ-diol (3) and cycloeucalenol (4) have been isolated from the leaves and stems of Fritillaria hupehensis Hsiao et K.C. Hsia. Their structures were elucidated on the basis of spectroscopic analysis.     

Regulation of K+ channels underlying the slow afterhyperpolarization in enteric afterhyperpolarization-generating myenteric neurons: role of calcium and phosphorylation

1. Myenteric afterhyperpolarization-generating myenteric (AH) neurons serve as intrinsic primary afferent neurons of the enteric nervous system and generate prolonged or slow afterhyperpolarizing potentials (slow AHP). The slow AHP is generated by an increase in a Ca2+-activated K+ conductance (gK-Ca) and is inhibited by enteric neurotransmitters leading to increased excitability. 2. Using cell-attached patch-clamp recordings from AH neurons, we have shown that K+ channels with an intermediate unitary conductance (IK channels) open following action potential firing. 3. In excised patches from AH neurons, we have identified an IK-like channel that can be activated by submicromolar levels of cytoplasmic Ca2+ and is not voltage dependent. 4. Application of the catalytic subunit of cAMP-dependent protein kinase to the cytoplasmic surface of inside-out patches inhibits the opening of IK-like channels previously activated by Ca2+. 5. The IK-like channels are resistant to external tetraethylammonium (5 mmol/L) and apamin (0.3-1 micro mol/L), but are inhibited by clotrimazole (10 micro mol/L). 6. Our present data support the idea that an increase in the open probability of IK-like channels in AH neurons following an increase in cytoplasmic [Ca2+] is responsible for the slow AHP and their opening is modulated by kinases.