Roberts铜盐法测定蔗汁葡聚糖含量的热效应——淀粉对受热蔗汁葡聚糖测定的影响

作者从研究中发现:用Roberts铜盐法测定蔗汁样本葡聚糖含量时,所得结果与蔗汁的受热有关,受热蔗汁的测定值高于真实值,作者将这种现象暂称为Roberts铜盐法测定蔗汁样本葡聚糖含量的热效应。研究表明:蔗汁中的淀粉是引起热效应的重要因素。本文最后提出了一种由淀粉引起的热效应的可行校正方法。     

Dietary Habits,Selenium, Copper,Zinc and Total Antioxidant Status in Serum in Relation to Cognitive Functions of Patients with Alzheimer’s Disease

Oxidative stress plays a crucial role in the neurodegenerative process and can impair cognitive functions. In the prevention of Alzheimer’s disease (AD), an adequate consumption of dietary antioxidants may be a major factor. The objective of the study was to estimate selenium (Se), copper (Cu), zinc (Zn), and total antioxidant status (TAS) in the serum of patients with AD in relation to their cognitive functions and dietary habits. A total of 110 patients (aged 54–93 years) with early or moderate AD, as well as 60 healthy people (aged 52–83 years) were studied. The severity of the disease was assessed using the mini-mental state examination (MMSE) scale. Food-frequency questionnaires were implemented to collect the dietary data. The concentrations of Se, Cu and Zn in the sera were determined by the atomic absorption spectrometry method. TAS was estimated spectrophotometrically using ready-made kits (Randox). Significantly lower concentrations of Se, Zn and TAS, and higher Cu:Zn ratio in the serum of patients with AD, compared to healthy people, were observed. A low correlation between the MMSE score and TAS in the serum of AD patients and significantly higher MMSE values in patients with TAS above the reference range were also noted. In patients with serum Cu concentration above the norm, significantly lower MMSE values were found. Selected dietary habits such as the frequency of consumption of various food products had a significant impact on the concentration of the assessed parameters in the serum of people with AD.     

Copper-inhibition of the growth of oral streptococci and actinomyces

Copper ions were found to inhibit the rate of growth in broth culture of Streptococcus mitis, Streptococcus mutans, Streptococcus salivarious, Streptococcus sanguis, Actinomyces viscosus and Actinomyces naeslundii. In all cases, 10^?3 M copper inhibited the rate of growth, whereas 10^?4 M and lower concentrations had little or no effect. At the concentrations used in mouthwashes one mode of action of copper ions is to reduce the rate of growth of oral bacteria in vitro.     

癌高发区非癌症患者血清铜、锌水平及影响因素

目的：探讨癌高发区非癌症患者的血清铜、血清锌水平及其影响因素。方法：用原子吸收法测定血清铜、血清锌值。并对膳食、健康状况和经济水平等因素进行问卷调查,采用单因素相关、逐步回归分析方法来研究癌高发区、对照区年龄在40～60岁长期居住的非癌症患者人群及其多种因素影响的关系。结果：癌高发区人群血清铜、血清铜锌比值明显高于对照区,血清锌值明显低于对照区。血清铜值与现病史和地区有关．男性血清铜高于女性,血清锌值随经济水平和肉摄入量的增加而增高。地区、现病史和性别对血清铜锌比值影响比其它因素更明显。结论：现病史和地区是影响血清铜锌比值的重要因素。血清铜锌比值可考虑作为评价癌高发区的因素之一。     

急性心肌缺血时锌铜含量的变化及影响

目的　探讨急性心肌缺血时锌铜含量的变化及影响。方法　分别测定急性心肌缺血家兔局部心肌、心血、外周血及 15 0例急性心肌缺血病人血清中锌铜含量 ,并与对照组比较。腹腔给予急性心肌缺血家兔补充锌铜溶液 ,观察给予前后ECG变化。结果　家兔随心肌缺血时间延长 ,锌铜含量在局部心肌中逐渐减少 ,心血及外周血中逐渐增加 ,与对照组比差异显著 (P <0 .0 5 ) ;急性心肌缺血病人血清锌铜含量明显降低 (P <0 .0 1) ;家兔腹腔给予锌铜溶液心肌缺血及心律失常明显好转。结论　急性心肌缺血早期锌铜含量变化能引起心电活动的改变 ,可能是猝死的原因之一。补充锌铜对纠正心律失常及心肌缺血有一定作用。     

Screening and identification of 3-aryl-quinolin-2-one derivatives as antiviral agents against influenza A

Quinolin-2-one represents an important and valuable chemical motif that possesses a wide variety of biological activities; however, the anti-influenza activities of quinolin-2-one-containing compounds were rarely reported. Herein, we describe the screening and identification of 3-aryl-quinolin-2-one derivatives as a novel class of antiviral agents. The 3-aryl-quinolinone derivatives were synthesized via an efficient copper-catalyzed reaction cascade that we previously developed. Using this synthetic method, preliminary structure–activity relationships of this scaffold against the influenza A virus infection were systematically explored. The most potent compound 34 displayed IC₅₀ values of 2.14 and 4.88 μM against the replication of H3N2 (A/HK/8/68) and H1N1 (A/WSN/33) strains, respectively, without apparent cytotoxicity on MDCK cells. We further demonstrated that 27 and 34 potently inhibited the plaque formation of the IAV, rendering this scaffold attractive for pursuing novel anti-influenza agents.     

Neocuproine,a selective Cu(I) chelator,and the relaxation of rat vascular smooth muscle by S-nitrosothiols

1. A study has been made of the effect of neocuproine, a specific Cu(I) chelator, on vasodilator responses of rat isolated perfused tail artery to two nitrosothiols: S-nitroso-N-acetyl-D,L-penicillamine (SNAP) and S-nitroso-glutathione (GSNO).
2. Bolus injections (10 μl) of SNAP or GSNO (10⁻⁷–10⁻³ M) were delivered into the lumen of perfused vessels pre-contracted with sufficient phenylephrine (1–7 μM) to develop pressures of 100–120 mmHg. Two kinds of experiment were made: SNAP and GSNO were either (a) pre-mixed with neocuproine (10⁻⁴ M) and then injected into arteries; or (b) vessels were continuously perfused with neocuproine (10⁻⁵ M) and then injected with either pure SNAP or GSNO.
3. In each case, neocuproine significantly attenuated vasodilator responses to both nitrosothiols, although the nature of the inhibitory effect differed in the two types of experiment. We conclude that the ability of exogenous nitrosothiols to relax vascular smooth muscle in our ex vivo model is dependent upon a Cu(I) catalyzed process. Evidence is presented which suggests that a similar Cu(I)-dependent mechanism is responsible for the release of NO from endogenous nitrosothiols and that this process may assist in maintaining vasodilator tone in vivo.

     

某些酶活性变化对评价生长发育期大鼠锌营养的意义

雄性断乳大鼠随机分为低锌组、高锌组、正常锌组和低锌组的高锌饲料对饲组。喂相应饲料２０天后,低锌组的部分大鼠改喂高锌饲料（低 高锌组）,高锌组的部分大鼠改喂低锌饲料（高 低锌组）。分别于实验期０、２０、５０和７０天时处死。测定血浆碱性磷酸酶、５′ 核苷酸酶和铜 锌型超氧化物歧化酶活性、血浆锌及肾脏锌含量变化,以考核它们对评价锌营养状况的意义。结果表明：碱性磷酸酶、５′ 核苷酸酶以及血浆锌浓度变化对缺锌或／和补锌反应敏感。短期缺锌时（２０天）碱性磷酸酶活性就显著降低,并随缺锌时间延长该酶活性持续降低,而短期补锌（３０天）后又能显著增加其活性。受锌营养状况影响,血浆５′ 核苷酸酶活性也有类似的变化趋势。但这些酶活性又受增龄因素的影响,即随实验期增加,正常锌组碱性磷酸酶活性呈降低趋势,而５′ 核苷酸酶活性则呈增加趋势。长期严重缺锌可以影响铜 锌型超氧化物歧化酶活性;补锌后在实验期内未见到它的活性显著增加。随实验期增加,低锌组血浆锌持续降低,５０天时,显著低于高锌组;７０天时,低锌组和高 低锌组的血浆锌也显著低于高锌和低 高锌组。这些结果提示,碱性磷酸酶和５′ 核苷酸酶的活性及血浆锌变化对评价大鼠锌营养状况有一定的意?     

两种产后立即放置TCu380A宫内节育器方法的比较——910例12个月随访分析

目的：比较徒手和卵圆钳两种方法对产后立即放置（ＩＰＰＩ）宫内节育器（ＩＵＤ）效果的影响。方法：将９１０例阴道分娩产妇（其中９７．７％是首次分娩）随机分成两组，于胎盘娩出后１０分钟内放置ＴＣｕ３８０ＡＩＵＤ，其中４７０例徒手放置（手放组），４４０例用卵圆钳放置（钳放组）。随访１２个月，以生命表法统计、χ２检验比较两种放置方法的脱落率、妊娠率、因症取出率等。结果：６和１２个月的随访率分别为９５．１６％和９２．６４％。９１０例中未发生子宫穿孔和感染，仅手放组有１例带器妊娠。放置后主要停用原因是脱落，手放组与钳放组１２个月的粗累积脱落率分别为１５．８６／１００妇女和１５．８８／１００妇女，因症（出血、疼痛）取出率分别为２．１１／１００妇女和１．５７／１００妇女，差异无显著性（Ｐ均＞０．０５）。结论：徒手放置或卵圆钳放置对ＩＰＰＩ的效果无明显影响；ＴＣｕ３８０ＡＩＵＤ适合中国妇女产后立即放置。     

银杏叶对低密度脂蛋白氧化修饰抑制作用的时效研究

目的　探讨银杏叶不同有效成分 [总提取物EGB76 1 ;银杏叶总黄酮 (GF) ;银杏叶总内酯 (GT) ]对Fe2 + 或Cu2 + 诱导的人血浆低密度脂蛋白 (LDL)氧化修饰的抑制作用与时间的变化关系。方法　使用荧光分光光度法测定了LDL在Fe2 + 或Cu2 + 诱导下 ,分别加入上述三种有效成分 ,作用 1、2、4、6h后自身荧光物质(LF)、丙二醛 (MDA)和维生素E(VitE)含量。结果　三种有效成分对LF和MDA的生成及VitE的消耗有抑制作用 ,抑制作用在 4h内随作用时间延长逐渐明显 ,6h时抑制作用明显减弱。结论　银杏叶对低密度脂蛋白氧化修饰抑制作用具有一定的时效关系