紫绀类先天性心脏病患者红细胞的初步研究

正常人的红细胞形态、膜结构和组成、膜上各种酶活性等研究报道甚多,膜与某些疾病的关系也常有报道,但心血管疾病,包括紫绀类先天性心脏病对红细胞及其膜有无影响,有何影响,尚未见有研究性文章。近二年,我们对紫绀类先天性心脏病患者红细胞及其膜进行了如下研究:①紫绀类先天性心脏病中法乐氏四联症患者红细胞形态的相差显微镜和电镜观察,     

高原红细胞增多症患者肠道菌群变化研究

目的 探究高原红细胞增多症患者肠道菌群变化及相关意义。 方法 招募西藏那曲地区血红蛋白(hemoglobin,HB)含量高于210 g/L的高原红细胞增多症患者12人,对照组(170 g/L结果 高原红细胞增多症患者的血红蛋白水平以及红细胞比容显著高于对照组。红细胞增多症患者的肠道菌群整体结构改变不明显,多样性没有显著差异。红细胞增多症患者的粪便菌群出现厚壁菌门中梭状芽胞杆菌BB60属、纺锤链杆菌属、厌氧棒杆菌属、霍氏真杆菌,变形菌门中假单胞菌属,拟杆菌门中副拟杆菌属丰度的显著增高。这些菌属改变经KEGG预测分析显示与代谢紊乱相关。斯皮尔曼分析显示多种菌群改变与血红蛋白水平以及红细胞比容正相关。 结论 高原红细胞增多症患者肠道菌群出现紊乱,菌群变化与代谢紊乱和红细胞增多相关。     

阵发性睡眠性血红蛋白尿症红细胞乙酰胆碱酯酶的研究

用化学方法测定了乙酰胆碱脂酶（ＡｃｈＥ）活性,阵发性睡眠性血红蛋白尿症（ＰＮＨ）红细胞远低于正常红细胞。为了进一步研究ＰＮＨ ＡｃｈＥ（一）的红细胞,采用Ｐｒｏｔｅｉｎ Ａ Ｓｅｐｈａｒｏｓｅ ６ＭＢ结合ＡｃｈＥ单抗亲和层析法分离出ＰＮＨＡｃｈＥ（一）的红细胞。同间接免疫荧光流式细胞术检测,ＰＮＨ细胞ＡｃｈＥ低于正常,而ＰＮＨ ＡｃｈＥ（一）红细胞未能检出ＡｃｈＥ。＾３Ｈ－肌醇标记实验证明,正常     

阵发性睡眠性血红蛋白尿症红细胞乙酰胆碱酯酶的研究

用化学方法测定了乙酰胆碱脂酶（ＡｃｈＥ）活性,阵发性睡眠性血红蛋白尿症（ＰＮＨ）红细胞远低于正常红细胞。为了进一步研究ＰＮＨＡｃｈＥ（—）的红细胞,采用Ｐｒｏｔｅｉｎ　Ａ　Ｓｅｐｈａｒｏｓｅ　６ＭＢ结合ＡｃｈＥ单抗亲和层析法分离出ＰＮＨＡｃｈＥ（—）的红细胞。用间接免疫荧光流式细胞术检测,ＰＮＨ细胞ＡｃｈＥ低于正常,而ＰＮＨＡｃｈＥ（—）红细胞未能检出ＡｃｈＥ。３Ｈ－肌醇标记实验证明,正常红细胞膜区带４．１处有较高的放射活性,而ＰＮＨ红细胞极低,ＰＮＨＡｃｈＥ（—）红细胞完全无放射活性。用ＡｃｈＥ抗体做免疫印渍实验证明了ＡｃｈＥ存在区带４．１部位。ＤＭＰＣ诱导正常和ＰＮＨ红细胞,检测二者囊泡化的程度,发现ＰＮＨ病人红细胞远比正常人红细胞易于囊泡化。     

高原红细胞增多症患者红细胞二磷酸甘油酸和氧亲和力变化的探讨

在海拔４３００ｍ地区,对１８名移居汉族、２４名世居藏族和２１名高原红细胞增多症（ＨＡＰＣ）患者测定了２,３—二磷酸甘油酸（２,３—ＤＰＧ）和肺通气功能,并进行了血气分析。结果显示：ＨＡＰＣ患者的全血和红细胞内２,３—ＤＰ６浓度均显著高于健康组,但世居、移居健康组之间无明显差异。ＨＡＰＣ组的红细胞２,３—ＤＰＧ和Ｐｄｏ＿２呈显著负相关（ｒ＝—０．７７１,Ｐ＜０．０１）,而在健康组无显著相关（ｒ＝—０．２６,Ｐ＞０．０５）。ＨＡＰＣ组与健康组相比,ｐＨ、Ｐａｏ＿２和Ｓａｏ＿２降低,Ｐａｃｏ＿２和肺泡动脉氧分压差增高。ＨＡＰＣ病人Ｐ＿（５０）为３．７５±０．６６ｋＰａ,健康组为３．４０±０．１２ｋＰａ（Ｐ＜０．０５）,Ｐ＿（５０）与２,３－ＤＰＧ呈正相关（ｒ＝０．５９２,Ｐ＜０．０５）。ＨＡＰＣ组最大呼气中段流量和５０％肺活量最大呼气量明显低于健康组（Ｐ＜０．０１）。本研究提示：①ＨＡＰＣ患者的低氧血症可能与血中２,３－ＤＰＧ浓度过高有关;②轻度肺功能异常亦可促使红细胞进一步增多。     

高原红细胞增多症患者红细胞二磷酸甘油酸和氧亲和力变…

在海拔４３００地区,对１８名移居汉族、２４名世居藏族和２１名高原红细胞增多症（ＨＡＰＣ）患者测定了２,３－二磷酸甘油酸（２,３－ＤＰＧ）和肺通气功能,并进行了血气分析。结果显示：ＨＡＰＣ患者的全血和红细胞内２,３－ＤＰＧ深度均显著高于健康组,但世居、移居健康组之间无明显差异。ＨＡＰＣ组的红细胞２,３－ＤＰＧ和Ｐａｏ２呈显著负相关（ｒ＝－０．７７１,Ｐ＜０．０１）,而在健康组无显著相关（ｒ＝－０＼２     

红细胞生成及调节的研究进展

本文以小鼠模型为例,描述了红细胞在哺乳动物胚胎和成年期发育、分化的一般过程,重点介绍了原始红系造血、定向红系造血、稳态造血和应激造血的概念,同时归纳梳理了关于成红细胞岛和红细胞生成调控等方面的研究进展。     

肾脏与红细胞生成的关系

很早人们就发现,当机体缺氧或失血时,红细胞生成即加速,这是因为在血浆中有一种活性物质,能够刺激红细胞的生成。1948年这种活性物质被命名为红细胞生成素(Erythropoietin)。后来发现,肾脏是产生红细胞生成素的主要器官。杰克逊(Jacobson)等人首先观察到,当动物切除双侧肾脏后,血浆中红细胞生成素迅速减少,且缺氧或失血时,血浆中也不再出现该物质。临床上,患肾脏肿瘤的病人,有时出现红细胞增多,其血中红细胞生成素也增多。此后,从肾肿瘤组织中     

高原红细胞增多症患者夜间睡眠呼吸变化

高原睡眠结构紊乱和周期性呼吸已有较多记载,我们对海拔3730m处8例高原红细胞增多症(HAPC)患者在高原和平原夜间睡眠呼吸变化进行了研究,以探讨高原与平原对其夜间睡眠、呼吸和血氧饱和度(Sao_2)的影响。     

Congenital erythropoietic porphyria with two mutations of the uroporphyrinogen III synthase gene (Cys73Arg, Thr228Met)

Congenital erythropoietic porphyria (CEP) is an autosomal recessive inborn error of metabolism that results from the markedly deficient activity of uroporphyrinogen III synthase (UROS). We describe a 14-year-old girl with red urine since infancy, progressive blistering and scarring of the skin, and moderate hemolytic anemia. After years of skin damage, her face is mutilated; she has a bald patch on the scalp, hypertrichosis of the neck, areas of skin darkening, and limited joint movements of the hands. Total urine excretion and fecal total porphyrin were both markedly raised above normal levels. Sequencing of the UROS gene identified two mutations causing CEP (Cys73Arg, Thr228Met). The patient lesions are progressing. Bone marrow transplantation and/or gene therapy are proposed as the next steps in her treatment. In brief, we describe a CEP with confirmed two pathogenic mutations, severe phenotype and discuss the various treatment options available.     

Slaving the cytochrome P-450 dependent monooxygenase system by periodically applied light pulses

The light-induced enhancement of 7-ethoxycoumarin-O-deethylase activity was measured in a reconstituted system consisting of the enzyme P-450 II B1 (P-450_PB-B) and the NADPH-cytochrome P-450 reductase. The phases of the catalytic cycle of 2 · 10¹² protein complexes were locked by periodic application of light pulses (0.1 s duration, 1.2–2.5 s repetition time, and 390–470 nm 0.27 Joule/nmol P-450). More than 80% of the active reconstituted enzyme complexes worked in phase if the repetition time (1.32 s) was slightly smaller than the catalytic cycle time of the free running enzyme (1.54 s). The percentage of synchronized enzyme complexes as a function of the repetition time is shown. It is shown that the lifetime of the product-enzyme complex is shortened by the light.Abbreviations P-450 liver microsomal cytochrome P-450 - PB phenobarbitalOffprint requests to: H. Gruler     

陆生植物体内酶系统对UV-B辐射增强的响应

臭氧层减薄导致地表中波紫外线UV-B(280～320 nm)辐射的增强,UV-B辐射能量远高于可见光,且能被植物体内蛋白质和核酸等生物大分子吸收.酶是植物体内起催化作用的一类蛋白质,酶的数量和活性对UV-B辐射增强有强烈的响应.本文将近年来增强UV-B辐射对植物体内酶影响的研究工作进行了综述.主要包括抗氧化酶、核酮糖-1,5-二磷酸羧化酶、硝酸还原酶和谷氨酰胺合成酶.并就今后该方面的研究提出建议.     

Product Release Rather than Chelation Determines Metal Specificity for Ferrochelatase

Ferrochelatase (protoheme ferrolyase, E.C. 4.99.1.1) is the terminal enzyme in heme biosynthesis and catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme IX (heme). Within the past two years, X-ray crystallographic data obtained with human ferrochelatase have clearly shown that significant structural changes occur during catalysis that are predicted to facilitate metal insertion and product release. One unanswered question about ferrochelatase involves defining the mechanism whereby some metals, such as divalent Fe, Co, Ni, and Zn, can be used by the enzyme in vitro to produce the corresponding metalloporphyrins, while other metals, such as divalent Mn, Hg, Cd, or Pb, are inhibitors of the enzyme. Through the use of high-resolution X-ray crystallography along with characterization of metal species via their anomalous diffraction, the identity and position of Hg, Cd, Ni, or Mn in the center of enzyme-bound porphyrin macrocycle were determined. When Pb, Hg, Cd, or Ni was present in the macrocycle, the conserved π helix was in the extended, partially unwound “product release” state. Interestingly, in the structure of ferrochelatase with Mn-porphyrin bound, the π helix is not extended or unwound and is in the “substrate-bound” conformation. These findings show that at least in the cases of Mn, Pb, Cd, and Hg, metal “inhibition” of ferrochelatase is not due to the inability of the enzyme to insert the metal into the macrocycle or by binding to a second metal binding site as has been previously proposed. Rather, inhibition occurs after metal insertion and results from poor or diminished product release. Possible explanations for the lack of product release are proposed herein.     

堆肥化过程中生物酶活性的研究进展

在土壤酶学基础上发展起来的堆肥酶活研究能够从生化方面更深入地反映堆肥产品的腐熟程度、有机物质的降解以及重金属、芳香族化合物等有害物质的转化情况。文章系统总结了堆肥中酶活变化与原料成分、添加剂、微生物种类和数量、有机质降解的关系,不同酶活性之间的相关性以及堆肥中酶动力学的研究成果。提出筛选少数几个彼此独立的综合性酶指标,利用多元回归分析建立堆肥化与酶活的动态关系。同时提出堆肥中酶学发展的新思路,酶活检测技术的改进以及堆肥化中酶系统影响因素的探讨。     

Ultrasonic processing of enzymes: Effect on enzymatic activity of glucose oxidase

The effect of ultrasonication on the enzymatic stability, conformation, and catalytic activity of the important oxidoreductase, glucose oxidase (GOx), was investigated. Thus, buffer-free aqueous solutions of GOx were ultrasonicated (23 kHz at 4 °C) for different periods of time (10, 30, and 60 min) and studied in terms of their enzymatic activity. The ultrasonicated GOx was also studied by UV/vis and circular dichroism (CD) spectroscopy and by thermogravimetric analysis, and compared with pristine GOx. The CD spectra of ultrasonicated GOx showed a different composition with reduced α-helix and β-sheet fractions upon extended sonication compared with the pristine GOx. Along with the changes of the secondary structure, the enzymatic activity measured via HRP-coupled bioassay of the sonicated GOx showed a small corresponding decrease. Low temperature ultrasonic processing of GOx does not appreciably compromise bioactivity.     

产壳聚糖酶菌株的初步筛选

通过大量的筛选,获得了产壳聚糖酶较好的菌株Y2、Y4、Y8。其发酵液所产壳聚糖酶的酶活力分别为2．0U／ml,2．1U／ml,2．2U／ml。