代谢过程中相关氨基酸对高密度发酵生产腺苷蛋氨酸的影响

对清酒酵母高密度发酵生产S-腺苷-L-蛋氨酸（SAM）代谢过程中的相关氨基酸进行了考察。分别考察了十二种氨基酸对生物量和SAM产量的影响。实验发现L-胱氨酸、L-半胱氨酸、L-赖氨酸、L-组氨酸和L-蛋氨酸对SAM的积累有利,其中L-赖氨酸和L-组氨酸可以提高生物量,进而提高SAM的产量;L-胱氨酸、L-半胱氨酸和L-蛋氨酸可以提高SAM的含量,但是会抑制生物量的增长。通过3种补加方式的比较,得到最优的补加方式为：L-赖氨酸和L-组氨酸在培养基中加入,L-胱氨酸,L-半胱氨酸和L-蛋氨酸采取在发酵过程前24h流加。通过正交实验确定补加量为：L-赖氨酸为1g／L,L-组氨酸为1g／L,L-胱氨酸为1．5g／L,L-半胱氨酸为1g／L,L-蛋氨酸为1g／L。将此结果应用于5L发酵罐培养,SAM最高产量为5．53g/L,生物量为128g／L。     

硒代氨基酸的分析

本文介绍了用日立835-50氨基酸分析仪分析硒代氨酸(硒代胱氨酸、硒代蛋氨酸的方法,由于采用了较高浓度的盐酸水解,中性氨基酸沉淀等技术使两种硒代氨基酸实际样品的同时分析得以实现,国内未见报导。     

均匀设计在氨基酸分析中的应用——过甲酸氧化法测定胱、蛋氨酸的液相色谱条件筛选

本文介绍了均匀设计用于过甲酸氧化水解法测定胱、蛋氨酸液相色谱分析条件的筛选过程。均匀设计是中国科学院应用数学研究所方开泰先生提出的一种供多因素多水平而试验次数又比较少的试验设计法。本试验对液相色谱分析半胱磺酸、蛋氨酸砜的均匀试验结果用均匀设计的直观法和计算机逐步回归法进行了数据处理,总结了液相色谱条件对分析结果的影响规律,找出了过甲酸氧化水解法分析胱氨酸、蛋氨酸较为理想的液相色谱分析条件。用本试验筛选出的分析条件,对辽宁省饲料资源普查的49个样品进行分析,结果表明,所确定的分析条件是可靠的。本实验也为其它分析条件确定提供了一种可以借鉴的试验设计方法。     

由人发制备L-胱氨酸工艺的改进及某些机制探讨

<正> 本文介绍了由人发制备L-胱氨酸的生产工艺。为提高L-胱氨酸生产收率,对原工艺有些工序进行分析研究。作者为了能获得理想水解终点,因而作了不同盐酸浓度对L-胱氨酸收率影响曲线,认为用8.8N～9N盐酸浓度制备L-胱氨酸收率最佳;也做了不同时间水解人发对L-胱氨酸收率影响,对从人发中制备单一L-胱氨酸采用6.5小时水解时间,对L-胱氨酸收率最佳、最经济;水解浓缩液经中和后马上采用连续搅拌结晶;粗制时先采用液碱后用饱     

不同来源毛发酸水解液中胱氨酸含量的差异

<正> 以毛发为原料酸水解生产 L-胱氨酸已在我国许多单位进行,如何提高 L-胱氨酸的收得率,降低成本是生产中关键问题。L-胱氨酸的收得率与水解条件,中间提取条件是密切相关的,但在水解条件相同的情况下,不同来源的毛发酸水解液中 L-胱氨酸含量有无差别,对 L-胱氨酸收率有什么影响呢?我们1976年在广东省东莞县拷胶厂,对不同来源毛发酸水解液中 L-胱氨酸含量和产量进行了分析和试验。     

不同叶菜型甘薯品种的氨基酸含量及组成分析

选用7个叶菜型甘薯品种,测定分析了茎尖中氨基酸含量及组成。结果表明:甘薯茎尖的E/T值变幅为37.22%~39.60%,E/N值变幅为0.59~0.66,符合理想蛋白质的要求;各种人体必需氨基酸占氨基酸总量的相对含量大部分符合1973年FAO/WHO修订的人体必需氨基酸模式谱,仅蛋氨酸+半胱氨酸中度缺乏;在全部18种氨基酸中,以半胱氨酸、蛋氨酸、色氨酸的变异系数最大,其他15种氨基酸的变异系数较小。     

用Beckman 121MB型氨基酸分析仪快速分析含硫氨基酸和色氨酸

蛋白质中胱氨酸、蛋氨酸和色氨酸在用盐酸水解时损失较大,常用过甲酸氧化法和碱水解法处理。采用文中方法分析时间短,分辨率高,半胱磺酸、甲硫氨酸砜和色氨酸的保留时间分别为５．３、１１．６和２０．４分钟。每分析一个样品需２６分钟,且基线平稳、重复性好、色谱图清晰。     

酵母菌高产蛋氨酸机理的研究

乙硫氨酸是蛋氨酸的结构类似物,１５０μｇ／ｍｌ浓度的乙硫氨酸可抑制丝孢酵母（Ｔｒｉｃｈｏｓｐｏｒｏｎｃｕ－ｔａｎｅｕｍ）ＳＴ８５１生长,又能被蛋氨酸回复。经紫外线处理后,得到抗性突变株ＳＴ８５１－１０,菌体蛋氨酸含量提高了４３．５％。分析合成机理表明：该突变株ＳＴ８５１－１０的Ｓ－腺苷蛋氨酸合成酶活性降低,增大了细胞内蛋氨酸库（Ｍｅｔｈｉｏｎｉｎｅｐｏｏｌ）。     

恶臭假单胞菌TS1138转化生产L-胱氨酸的工艺研究

对以DL-2-氨基-△2-噻唑啉-4-羧酸(DL-2-amino-△2-thiazoline-4-carboxylic acid,DL-ATC)为底物原料,经微生物酶法催化合成L-半胱氨酸,并进一步氧化和分离纯化产物L-胱氨酸的生产工艺和条件进行了研究.建立了以恶臭假单胞菌TS1138(Pseudomonas putida TS1138)全细胞为酶源,反复多次催化底物合成L-半胱氨酸,并以2.0%二甲基亚砜(DMSO)为氧化剂氧化生成L-胱氨酸,进而通过001×7型阳离子交换树脂纯化胱氨酸的新工艺.采用高效液相色谱法考察该方法L-胱氨酸的总收率可以达到78.55%,纯度为99.12%.该方法简单高效,解决了酶稳定性差不能重复使用,而固定化酶方法繁琐成本高的问题,为我国L-半胱氨酸和L-胱氨酸的生产开辟一条新途径.     

恶臭假单胞菌TS1138转化生产L-胱氨酸的工艺研究

对以DL-2-氨基-?2-噻唑啉-4-羧酸(DL-2-amino-?2-thiazoline-4-carboxylic acid, DL-ATC)为底物原料, 经微生物酶法催化合成L-半胱氨酸, 并进一步氧化和分离纯化产物L-胱氨酸的生产工艺和条件进行了研究。建立了以恶臭假单胞菌TS1138 (Pseudomonas putida TS1138)全细胞为酶源, 反复多次催化底物合成L-半胱氨酸, 并以2.0%二甲基亚砜(DMSO)为氧化剂氧化生成L-胱氨酸, 进而通过001×7型阳离子交换树脂纯化胱氨酸的新工艺。采用高效液相色谱法考察该方法L-胱氨酸的总收率可以达到78.55%, 纯度为99.12%。该方法简单高效, 解决了酶稳定性差不能重复使用, 而固定化酶方法繁琐成本高的问题, 为我国L-半胱氨酸和L-胱氨酸的生产开辟一条新途径。     

Trx/TXNIP在脑卒中的研究进展

脑卒中是导致中老年人群死亡最主要原因之一,其具有较高的致死率和致残率,且每年的发病率呈逐年上升的趋势,严重危害人类的生命和健康,因此寻找有效的诊断及治疗脑卒中的靶点具有重要意义。硫氧还蛋白(Trx)是细胞内主要的硫醇还原剂,通过调节细胞内氧化还原状态,参与细胞内多种信号通路转导过程,具有二硫化物还原酶活性,通过抗氧化效应,减轻脑卒中后神经元氧化应激损伤。硫氧还原蛋白相互作蛋白(TXNIP)是Trx的内源性抑制剂,通过绑定/抑制Trx的活性,破坏细胞内氧化还原平衡,促进氧化应激,而抑制或敲除TXNIP具有明显的神经保护作用。最新研究表明Trx/TXNIP可经多种途径参与脑卒中病理生理过程。本文通过分析Trx和TXNIP的研究现状,以及探讨Trx系统在中枢神经系统中的定位和Trx系统在缺血性脑卒中的研究进展,展望Trx/TXNIP参与脑卒中的病理生理过程的信号途径,拟对Trx/TXNIP在脑卒中的作用机制进行综述,为脑卒中的治疗提供新思路。     

不同类型脑卒中患者血清同型半胱氨酸水平检测的临床意义

目的:检测不同类型脑卒中患者血清中同型半胱氨酸(Hcy)浓度,探究其临床意义。方法:将2011年2月至2014年10月期间入我院接受治疗的140例脑卒中患者纳入本次研究,作为研究组,其中包含64例脑梗死患者(CI组)、42例脑出血患者(CH组)以及34例短暂性脑缺血发作患者(TIA组),同时以同期135例体检健康者作为对照组。采用循环酶法测定所有研究对象血清Hcy水平,同时采用放射免疫法对其血清内维生素B12、叶酸浓度进行测定。结果:研究组血清Hcy浓度高于对照组,组间差异显著(P0.05);研究组的叶酸及Vit B12低于对照组,组间差异均有统计学意义(P0.05);两组年龄、TC、TG、LDL-C等指标在组间存在差异(P0.05),两组HDL-C差异无统计学意义(P0.05)。CI组、CH组、TIA组血清Hcy水平均高于对照组,差异均有统计学意义(P0.05),但在CI组、CH组、TIA组三组相互对比中,组间差异无统计学意义(P0.05)。进展性脑梗死组血清内Hcy浓度高于完全性脑梗死组,组间数据具有显著差异(P0.05)。不同NIHSS评分患者血清内Hcy浓度不同,评分越高,Hcy浓度越高,两者呈显著正相关关系(P0.05)。回归性相关分析,脑卒中发病危险因素为高Hcy、高总胆固醇、高LDL-C、低叶酸、低Vit B12(P0.05)。结论:脑卒中患者与健康人群血清Hcy水平存在差异,不同类型脑卒中血清Hcy水平存在差异,且血清中同型半胱氨酸水平与脑卒中发病存在相关性,因此可以将血清Hcy作为脑卒中预测、诊断及预后判断的重要指标之一。     

综合护理对脑卒中患者下肢深静脉血栓形成的预防效果

目的:分析综合护理干预在脑卒中偏瘫患者下肢深静脉血栓形成中的预防效果及临床效应。方法:将120例经颅部CT或MRI确诊的脑卒中患者分为观察组和对照组,每组各60例。对照组给予常规护理干预,观察组进行综合护理干预,比较不同干预措施患者下肢深静脉血栓形成情况。结果:观察组DVT发生率为3.33%,对照组为18.33%,观察组干预效果明显优于对照组,差异有统计学意义(P0.05)。结论:综合护理干预可有效降低脑卒中偏瘫患者DVT的形成,在脑卒中偏瘫患者DVT方面具有显著的预防作用与临床效应,值得借鉴。     

首发缺血性脑卒中患者血清Hcy和EPO水平的变化及临床意义

目的:探究首发缺血性脑卒中患者血清同型半胱氨酸(Hcy)和红细胞生成素(EPO)水平的变化和意义。方法:于2013年10月-2015年4月我科收治的首发缺血性脑卒中患者中随机选取98例作为观察组,另选取同期健康体检者98例作为对照组,检测患者的血小板、血浆纤维蛋白原(Fib)以及血白细胞水平,比较两组血清Hcy、EPO、血小板、Fib及血白细胞水平,使用Logistic回归分析法评价缺血性脑卒中病发的危险因素,采用Spearman法对血清Hcy与EPO间相关性进行分析。结果:观察组的Hcy(23.52±12.15)m IU/L与EPO(34.61±11.25)m IU/L水平显著高于对照组的(10.57±2.18)m IU/L、(17.54±5.83)m IU/L;观察组血小板、血浆纤维蛋白原(fibrinogen,Fib)及血白细胞水平均高于对照组;差异均有统计学意义(均P0.05)。经Logistic回归分析法分析可知,Hcy为缺血性脑卒中病发的独立因素,经Spearman相关性分析显示,首发缺血性脑卒中患者EPO水平与Hcy呈正相关。结论:缺血性脑卒中病发与血清Hcy和EPO水平升高密切相关,且Hcy是导致缺血性脑卒中病发的高危因素。     

两种蝮蛇抗栓酶与传统方法治疗缺血性脑卒中146例的疗效分析

采用东北白眉蝮蛇抗栓酶、江浙蝮蛇抗栓酶、丹参加低右治疗缺血性脑卒中,以一般对症处理治疗作为对照组结果显示东北白屑蝮蛇抗栓酶治疗缺血性脑卒中与对照组比较 P 值有显著性差异,而其他两组与对照组比较 P 值无显著性差异.     

Attenuation of Inflammation by DJ-1 May Be a Drug Target for Cerebral Ischemia–Reperfusion Injury

Neurochemical Research - The pathophysiological process of cerebral apoplexy is complex, and there are currently no specific drugs for this condition. The study of effective drug targets has become...     

Pituitary Apoplexy Secondary to Thrombocytopenia Due to Dengue Hemorrhagic Fever: A Case Report and Review of the Literature

Objective:To present a case of pituitary apoplexy secondary to thrombocytopenia associated with dengue hemorrhagic fever (DHF).Methods:In this case study, we review the presentation, evaluation, diagnosis, and management of a case of pituitary apoplexy in the setting of DHF. We also searched the literature for cases of pituitary apoplexy associated with thrombocytopenia and review their clinical presentation, management, and outcome.Results:A 53-year-old man presented with fever, lethargy, and worsening headache. Routine investigations revealed thrombocytopenia secondary to dengue fever. He developed symptoms of a cavernous sinus lesion the next day. Urgent magnetic resonance imaging revealed pituitary apoplexy in a pituitary macroadenoma. A transsphenoidal surgery was done and histology was consistent with apoplexy in a prolactin/follicle-stimulating hormone macroadenoma. Subsequently, the patient developed permanent deficits of anterior pituitary hormones. We review 8 other cases of pituitary apoplexy associated with thrombocyto-penia reported in the literature.Conclusion:Thrombocytopenia due to various causes may be a predisposing factor for pituitary apoplexy in a patient with underlying pituitary disease. In view of the tendency for bleeding associated with thrombocytopenia, the risks of surgical intervention have to be carefully weighed against the potential benefits. Indications for surgery would include progressive alteration of consciousness, visual disturbances, and opthalmoplegia despite conservative management. Patients with underlying pituitary macroadenomas with optic chiasm compression have a worse prognosis, and the chances of recovery, even with early surgery, are limited.     

Guía de práctica clínica para el diagnóstico y tratamiento de la apoplejía hipofisaria

Classic pituitary apoplexy (PA) is an acute, life-threatening clinical syndrome caused by acute hemorrhage and/or infarction of the pituitary gland. PA is considered a neuroendocrinological emergency. However, there is no consensus about the best options for PA diagnosis and management.ObjectiveTo develop a clinical practice guideline with a number of recommendations for diagnosis and treatment of patients with PA based on the medical evidence available, in order to help clinicians involved in their care.MethodsThe clinical guideline for diagnosis and treatment of pituitary apoplexy issued in 2006 by the Neuroendocrinology Working Group of the Spanish Society of Endocrinology and Nutrition (SEEN) and the British Clinical Practice Guideline published in 2011 were taken as the basis. The text has been adapted to the format used in most international medical journals. For this, after updated medical literature, the quality of evidence and the strength of the recommendations were evaluated using the system proposed by the Agency for Health Care Policy and Research (AHCPR).ConclusionsDiagnosis of pituitary apoplexy should be considered in all patients with acute severe headache with or without neuro-ophthalmic signs. Patients with PA must undergo a complete history and physical examination. All patients with suspected pituitary apoplexy should have urgent blood samples drawn to test electrolytes, renal function, liver function, coagulation screen, complete blood count, and basal levels of pituitary and peripheral hormones, and to rule out adrenocorticotropic hormone (ACTH) deficiency. Formal visual field assessment should be performed when the patient is clinically stable. Magnetic resonance imaging (MRI) is the imaging test of choice to confirm diagnosis. Indications for empirical urgent corticosteroid therapy in patients with PA include hemodynamic instability, impaired consciousness, reduced visual acuity, and severe visual field defects. In patients with these severe neuro-ophthalmic signs, surgery should be considered. Surgery should preferably be performed within seven days of the onset of symptoms. Patients with mild and stable signs may be managed conservatively with careful monitoring. Treatment and long-term follow-up of patients with PA should be conducted by a multidisciplinary team consisting, amongst others, of an experienced pituitary neurosurgeon, an ophthalmologist, and an endocrinologist.     

钠离子通道研究进展

细胞电活动是生命现象的基本特征之一,而离子通道是其结构和功能的基础。因此,研究离子通道作用机制具有重大的理论和现实意义。许多神经系统和心血管疾病,如多发性硬化症、癫痫、脑溢血、神经痛、Brugada综合征(BrS)、进行性心脏传导缺陷(PCCD)和原发性心室纤颤(IVF)等,都与钠离子通道氨基酸序列和结构发生的改变有关。该文对钠离子通道的研究进展进行综述。     

Association of Dengue Hemorrhagic Fever With Multiple Risk Factors for Pituitary Apoplexy

ObjectiveTo describe pituitary apoplexy that developed during the course of dengue hemorrhagic fever.MethodsWe describe the clinical findings, laboratory test results, imaging findings, and clinical course of the study patients.ResultsPatient 1 was a 40-year-old man who developed clinical signs and symptoms of dengue, which was confirmed by serologic testing. He presented with thrombocytopenia and developed severe headache and vomiting. During hospitalization, acromegaly was suspected because of the characteristic disease phenotype. Magnetic resonance imaging confirmed the diagnosis of pituitary apoplexy. Subsequently, the biochemical diagnosis of acromegaly was confirmed, and the patient underwent transsphenoidal surgery. Histopathologic examination showed signs of recent bleeding. Patient 2 was a 38-year-old man with a macroprolactinoma, who had been treated with cabergoline for 10 weeks and had shown improvement on laboratory testing and imaging. The patient then presented with clinical symptoms of dengue (confirmed serologically) and thrombocytopenia. He developed bilateral hemianopsia, and magnetic resonance imaging showed enlargement of the pituitary adenoma with signs of intratumoral bleeding. The patient underwent transsphenoidal surgery, and histopathologic examination documented a pituitary adenoma diffusely infiltrated by blood cells.ConclusionsWe describe dengue as a probable novel condition for pituitary apoplexy because it may be associated with multiple risk factors for pituitary infarction or bleeding. Physicians should suspect pituitary apoplexy in patients with dengue hemorrhagic fever who develop a rapid onset of severe headache and vision defects, even in those without known pituitary adenomas. (Endocr Pract. 2012;18:e97-e101)