野生型组织型纤溶酶原激活剂工程细胞株生物学特性分析

组织型纤溶酶原激活剂（ｔ－ＰＡ）是体内丝氨酸类蛋白酶。它能激活纤维蛋白溶酶原生成纤溶酶，后者将不溶性的纤维蛋白降解为可溶性肽段，使血栓溶解，血管再通。而且由于它与纤维蛋白有高亲和力，只激活血栓表面纤溶酶原，溶解局部血栓，因而引起全身出血倾向小。目前，...     

神经放射学与血脑屏障

本通过复习血脑屏障的解剖、生理、及生化研究的最新进展，介绍现代神经影像诊断学中和各类成像技术在中枢神经系统的应用中与血脑屏障的关系。     

中医药对血脑屏障影响的研究进展

血脑屏障(Blood Brain Barrian,BBB)是中枢神经系统和血液的分界面,生理状态下它限制了血液中某些物质进入中枢神经系统,从而维持中枢神经系统内环境的稳定[1].由于血脑屏障的存在,有些作用于中枢神经系统的药物受到屏蔽,不能发挥作用.另外当脑组织发生病理改变时,血脑屏障的结构受损,可发生病理性通透性增加,致血浆中有害成分进入脑内,可进一步加重脑组织的损伤[2].如何协助生理状态下药物通过血脑屏障,以及加强脑组织损伤后血脑屏障的保护作用是目前研究的热点.本文参考近年来相关研究文献,重点讨论和综述中医药对血脑屏障的影响.     

HCV NS3丝氨酸蛋白酶与野生型P53相互作用的研究

目的：探讨HCV NS3丝氨酸蛋白酶与P53蛋白之间的关系。为研究NS3丝氨酸蛋白酶在HCV所致肝癌发生发展机制中的作用奠定基础。方法：构建HCV NS3丝氨酸蛋白酶基因及其N端缺失突变体的重组质粒,通过酵母双杂交系统定性及定量检测P53与NS3及共突变体的相互作用。结果：HCV NS3丝氨酸蛋白酶、N端缺失15个氨基酸及缺失30个氨基酸的NS3丝氨酸蛋白酶与P53均有相互作用,且相互作用的强度无显著差异,结论：HCV NS3丝氨酸蛋白酶与P53之间确定存在相互作用,但NS3参与相互作用的区段不在N2S3的N端,而在其C端。     

血脑屏障及其在CT检查中有何意义？

血脑屏障(Blood Brain Barrier．BBB)实际上包括三种屏障即：血脑屏障、血脑脊液屏障及脑脊液脑屏障，使彼此间的物质交换有一定的选择性，以适应中枢神经系统对内环境的特殊要求。     

评价药物通过血脑屏障方法现状

血脑屏障是脑屏障最重要的组成部分,维持着中枢神经系统微环境的稳定,但同时也限制了多数药物进入脑组织对神经系统疾病的治疗作用。通过各种方法修饰药物使之能够进入脑组织成为药物学家的难题,而评价药物通过血脑屏障也成为其中一个重要课题。本文按实验对象类型分为动物活体、离体脑组织、体外血脑屏障模型、数学模型四大类进行综评。     

夏秋季节严防乙脑

流行性乙型脑炎是由乙脑病毒引起的虫媒传染病，简称“乙脑”。乙脑病毒为嗜神经毒，主要侵犯中枢神经系统。携带有这种病毒的库蚊、伊蚊叮咬人体后，就将病毒释入人的血液循环系统，人体发病与否不仅取决于病毒的数量和毒力，而且取决于人体的防御机能。当人体的抵抗力强时，只形成短暂的病毒血症，病毒很快被消灭，不侵入中枢神经系统，或为不显性感染；如果人体抵抗力低，感染病毒的数量多、毒力强，病毒可经血液循环通过血脑屏障进入中枢神经系统，在神经细胞内繁殖，引起脑炎。人体只要感染乙脑病毒，无论是否侵入中枢神经系统，病后均…     

细胞间缝隙连接通讯与中枢神经系统创伤

中枢神经系统功能极其重要，由于再生能力差以及血脑屏障等结构的存在，致使其创务后修复困难。原发性脑损伤创伤瞬间已形成，治疗前业已存在，所以众多学者在努力探索有效治疗手段的过程中，越来越重视减少中枢神经系统的继发损伤。无论中枢神经系统的结构和功能如何特殊，其细胞和组织的基本特性与机体的其他部分仍有许多共性，细胞间缝隙连接就是共中一种最普遍存在的结构，并由此形成了细胞间缝隙连接通讯（gap junctional intercellular communication ,GJIC）。     

LON基因下调对人乳腺癌细胞系MCF-7的增殖以及药物敏感性的影响

目的：应用RNAi的方法抑制丝氨酸蛋白酶LON表达，研究该丝氨酸蛋白酶的表达与肿瘤增殖以及药物敏感性之间的关系。方法：以人乳腺癌细胞MCF-7为研究对象，通过RNAi下调LON基因表达，采用RT—PCR法、MTT增殖实验、流式细胞术等技术进行检测。结果：在瞬时转染与稳定转染细胞株中，RT—PCR结果证实LON基因的表达明显下调；MTT增殖实验结果显示，LON基因的下调可导致细胞的增殖能力降低，并且能够增加对化疗药顺铂的药物敏感性。流式细胞仪检测显示LON基因的下调对细胞周期没有显著影响。结论：通过RNAi下调LON基因能够抑制肿瘤细胞的增殖并且与顺铂有协同作用，其抑制作用未造成细胞周期的改变。     

分泌性白细胞蛋白酶抑制因子在创伤愈合中的潜在应用前景

分泌性白细胞蛋白酶抑制因子（SLPI）是一种可以对抗各种丝氨酸蛋白酶活性的12kDa阳离子蛋白,其羧基末端具有抑制糜蛋白酶、胰弹性蛋白酶等方面的活性,氨基末端有抗细菌、抗真菌、抗逆转录病毒等多方面的活性。近来研究发现,SLPI可通过生长增殖、细胞凋亡、组织改建等多种途径来调控创伤微环境,从而影响创伤愈合进程。本文就SLPI参与创伤愈合过程的可能环节和作用综述如下。     

Histochemical characteristic of perivascular space in the brain with an advanced edema

Amorphorous and colorless spaces, Virchow-Robin spaces (VRS), were often found by HE stain around blood vessels in the edematous brain. Histochemical characteristic of the enlarged VRS caused by an advanced edema and detected by lectin stain using Griffonia simplicifolia I agglutinin in the brain stem, the occipital lobe and/or the cerebellum was examined by means of immunohistochemical method. After pretreatment with formic acid or proteinase K, formalin fixed-paraffin embedded tissue sections were incubated with antibodies (ABs) against plasma proteins such as amyloid P component, Ig G, albumin (Al), apolipoprotein E (Apo E), and lactotransferrin (Lf), and cellular proteins such as ubiquitin (Ubt), Tau-protein (Tau), glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), CD68 (KP-1) and heparansulfate proteoglycan (HSG). The tissue sections were also incubated with antibodies against alanyl aminopeptidase-S (AAP-S) and alanyl aminopeptidase-N (AAP-N) without pretreatment. The VRS showed intensive reactivity with ABs against Amy P, AAP-S and AAP-N, moderate with ABs against Apo E and HSG, weak with ABs against Ig G, Al and Lf, feeble with ABs against Ubt, Tau and CD 68, and no with ABs against GFAP and MBP, respectively. Although the substances detected in VRS might be of blood plasma origin resulting from abnormalities in the blood-brain barrier, the mechanisms whereby the serum proteins and/or other substances are enriched in VRS remain incompletely understood.     

Cystic lesions accompanying extra-axial tumours

We examined the mechanism of cyst formation in extra-axial tumours in the central nervous system (CNS). Cyst fluid, cerebrospinal fluid (CSF) and blood plasma were analysed in eight patients with nine peritumoral cysts: four with meningiomas, two with intracranial and two spinal intradural schwannomas. Measuring concentrations of various proteins [albumin, immunoglobulin G (IgG), IgA, α₂-macroglobulin and IgM] in cyst fluid, CSF and blood plasma provides insight into the state of the semipermeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier. Peritumoral cysts accompanying intra-axial brain tumours are the end result of disruption of the BBB and oedema formation. Unlike intra-axial tumours which lie embedded within nervous tissue, extra-axial tumours tend to be separated from nervous tissue by arachnoid and pia mater. High concentrations of proteins were measured in the cyst fluid, approaching blood plasma levels, suggesting a local barrier disruption, and passage across the arachnoid, pia mater and cortical/medullary layer into the CNS parenchyma, leaving the protein concentrations of CSF practically unchanged. We confirmed that very high concentrations of protein are to be found in tumour cysts, plasma proteins forming almost 90 % of the total protein in the cyst. We review current hypotheses on the pathogenesis of cysts accompanying neoplasms, particularly meningiomas and schwannomas, and conclude that the majority of proteins in cyst fluid in extra-axial, intradural meningiomas and schwannomas are plasma proteins. This provides a strong argument for pathogenesis of extra-axial intradural tumour cysts in favour of leakage of plasma proteins out of the tumour vessels into the nervous tissue. Received: 16 May 1998 Accepted: 6 February 1998     

蛋白质药物的入脑转运

治疗脑内疾病的有效途径是用载体向脑内运送蛋白质药物(如抗体、神经营养因子、生物活性酶等)。合适的脑靶向载体通过化学方法或分子生物学方法与蛋白质连接，携带蛋白质进入脑内，发挥药理作用。目前随着药物-亲和素／生物素-载体连接方法的成熟，以及脑靶向TAT-PTD小肽载体的探索，将可能会使大分子蛋白质进入脑内治疗脑内疾病成为常规的治疗方法。此外，这种方法也为治疗体内的其他器官疾病提供了思路。     

Proteases in doping control analysis

Urine manipulation in sports drug testing has become a serious problem for doping control laboratories, and recent scandals in elite endurance sports have revealed the problem of urine manipulation presumably using proteases, which will impede the detection of drugs such as erythropoietin (EPO) or other peptide hormones. Using commonly accepted analytical strategies, a protocol was developed enabling the determination of elevated protease activities in doping control specimens followed by the visualization of protein degradation and identification of proteases such as chymotrypsin, trypsin and papain. Therefore, protease detection kits based on fluorescein isothiocyanate-labeled casein were employed, and protease concentrations greater than 15 microg/mL of urine entailed subsequent 1-dimensional gel electrophoretic visualization of urinary proteins. The presence of 20 microg of proteases per mL of urine caused a complete degradation of proteins usually observed in urinary matrices ("trace of burning"), while respective proteases were still detected in spiked urine samples after 10 days of storage at + 4 and - 20 degrees C. Identification of target proteases at respective molecular weights was accomplished using bottom-up sequencing approaches based on in-gel digestion of separated enzymes followed by capillary liquid chromatography--Orbitrap tandem mass spectrometry.     

No promising antidote 25 years after the Tokyo subway sarin attack: A review

On the battlefields of Syria, many innocent civilians have been killed or injured by sarin poisoning. In Malaysia in February 2017, a North Korean man was assassinated with VX at Kuala Lumpur International Airport. In the face of such threats, a more effective antidote against organophosphonate acetylcholinesterase (AChE) inhibitors is needed, one that can freely penetrate into the central nervous system (CNS) through the blood–brain barrier (BBB). In the 1995 Tokyo subway sarin attack, which produced more than 6,000 victims, 2-pyridinealdoxime methiodide was the most commonly used antidote in hospitals, but it was unable to prevent CNS damage and no other oximes have been approved for use in Japan. Ultimately, 12 people died, and many victims had severe neurological injuries or sequelae. Although more than 25 years have passed since the incident, progress has been slow in the development of a new antidote that can penetrate the BBB, restore AChE activity in the CNS, and definitely prevent brain injury. From the perspectives of countering terrorism and protecting innocent people from nerve agent attacks, the search for nerve agent antidotes should be accelerated with the goals of improving both survival and quality of life. This review gives an overview of a series of our studies on the development of a new antidote since the Tokyo subway sarin attack and emphasizes that there is unfortunately still no promising antidote for saving the CNS in Japan.     

Anatomical and biochemical investigation of primary brain tumours

Cancerous transformation entails major biochemical changes including modifications of the energy metabolism of the cell, e.g. utilisation of glucose and other substrates, protein synthesis, and expression of receptors and antigens. Tumour growth also leads to heterogeneity in blood flow owing to focal necrosis, angiogenesis and metabolic demands, as well as disruption of transport mechanisms of substrates across cell membranes and other physiological boundaries such as the blood-brain barrier. All these biochemical, histological and anatomical changes can be assessed with emission tomography, X-ray computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Whereas anatomical imaging is aimed at the diagnosis of brain tumours, biochemical imaging is better suited for tissue characterisation. The identification of a tumoural mass and the assessment of its size and vascularisation are best achieved with X-ray CT and MRI, while biochemical imaging can provide additional information that is crucial for tumour classification, differential diagnosis and follow-up. As the assessment of variables such as water content, appearance of cystic lesions and location of the tumour are largely irrelevant for tissue characterisation, a number of probes have been employed for the assessment of the biochemical features of tumours. Since biochemical changes may be related to the growth rate of cancer cells, they can be thought of as markers of tumour cell proliferation. Biochemical imaging with radionuclides of processes that occur at a cellular level provides information that complements findings obtained by anatomical imaging aimed at depicting structural, vascular and histological changes. This review focusses on the clinical application of anatomical brain imaging and biochemical assessment with positron emission tomography, single-photon emission tomography and MRS in the diagnosis of primary brain tumours, as well as in follow-up.     

Evolution of brain imaging instrumentation

Computed tomography (CT) and static magnetic resonance imaging (MRI) are now the most common imaging modalities used for anatomic evaluation of pathologic processes affecting the brain. By contrast, radionuclide-based methods, including planar imaging, single-photon emission computed tomography (SPECT), and positron emission tomography (PET), are the most widely used methods for evaluating brain function. SPECT and PET have been evolving for a longer time than CT and MRI and have made significant contributions to understanding brain function. The pioneering work on cerebral flow early in the last century laid the foundation of measurement with radioactive gases. This was initially performed with scintillation counters, which gave way to single, then multiple scintillation and multiprobe detectors. The invention of rectilinear scanners, MARK series, Anger cameras, and SPECT imaging further advanced nuclear medicine's role in brain imaging. Measurement of regional cerebral blood flow by SPECT provides pathophysiologic information that directs patient management in a variety of central nervous disorders (CNS), with the greatest clinical impact found in cerebrovascular disease and seizure disorder. In the former, SPECT not only provides means of early detection and localization of acute strokes but can also direct thrombolysis and determine prognosis in the postcerebrovascular accident period. With respect to the latter, ictal SPECT can localize seizure foci so that patients with refractory disease can potentially undergo surgical resection of the affected area. In contrast to brain SPECT, brain PET images reflect regional cerebral metabolism. Because of neurovascular coupling, findings on SPECT and PET images are often comparable. PET, however, still has improved spatial resolution and is therefore more sensitive than SPECT, particularly in the evaluation of dementias. Brain PET instrumentation has greatly evolved from its infancy, when it was used in regional localization, to currently providing excellent resolution with imaging characteristics that can greatly impact clinical management. In addition, although ictal SPECT remains more sensitive than interictal PET for detection of seizure foci, the stringent conditions required for SPECT can be difficult to achieve, making interictal PET a very reasonable alternative. The clinical utility of PET and SPECT in neuropsychiatric and addictive disorders has not yet been defined, though a plethora of data exits. This arena of CNS disease has been the impetus for development of neurotransmitter-receptor-specific radioligands, which have already led to better understanding of dopaminergic, GABAergic, and serotonergic pathways. Another functional brain imaging technique that has gained broad acceptance since its invention in the early 1990 s, is functional MRI, which indirectly measures CNS neuronal activity by evaluating oxygenation levels of cerebral vessels. Despite other recent related developments, such as MR spectroscopy, arterial spin labeling, and diffusion tensor imaging, nuclear medicine-based techniques remain clinically relevant and robust modalities, especially with the ever-expanding armamentarium of radiotracers and radioligands in conjunction with industry-driven improvements in image-analysis hardware and software.     

Various indicators of brain metabolism during hypoxia and hyperthermia

Hypoxic, thermal and radiation tolerance of rats exposed to hypoxia and overheating for 4 to 22 days was measured. Activities of succinic dehydrogenase, lactate dehydrogenase and alkaline phosphomonoesterase as well as water content in the brain were examined biochemically and histochemically. Brain tolerance and metabolism varied in a phasic manner. Both specific and nonspecific adaptive reactions were identified. A direct correlation was established between hypoxic tolerance and aerobic oxidation decrease as well as enzyme-dependent transport in cerebral vascular walls. A relationship between CNS radiation tolerance and permeability of the blood-brain barrier was detected.     

Anatomical and biochemical investigation of primary brain tumours.

Cancerous transformation entails major biochemical changes including modifications of the energy metabolism of the cell, e.g. utilisation of glucose and other substrates, protein synthesis, and expression of receptors and antigens. Tumour growth also leads to heterogeneity in blood flow owing to focal necrosis, angiogenesis and metabolic demands, as well as disruption of transport mechanisms of substrates across cell membranes and other physiological boundaries such as the blood-brain barrier. All these biochemical, histological and anatomical changes can be assessed with emission tomography, X-ray computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Whereas anatomical imaging is aimed at the diagnosis of brain tumours, biochemical imaging is better suited for tissue characterisation. The identification of a tumoural mass and the assessment of its size and vascularisation are best achieved with X-ray CT and MRI, while biochemical imaging can provide additional information that is crucial for tumour classification, differential diagnosis and follow-up. As the assessment of variables such as water content, appearance of cystic lesions and location of the tumour are largely irrelevant for tissue characterisation, a number of probes have been employed for the assessment of the biochemical features of tumours. Since biochemical changes may be related to the growth rate of cancer cells, they can be thought of as markers of tumour cell proliferation. Biochemical imaging with radionuclides of processes that occur at a cellular level provides information that complements findings obtained by anatomical imaging aimed at depicting structural, vascular and histological changes. This review focusses on the clinical application of anatomical brain imaging and biochemical assessment with positron emission tomography, single-photon emission tomography and MRS in the diagnosis of primary brain tumours, as well as in follow-up.     

The behavior of 99mTc-hexamethylpropyleneamineoxime (99mTc-HMPAO) in blood and brain

99mTc-hexamethylpropyleneamineoxime (99mTc-HMPAO) is a reagent for scanning cerebral blood flow. We investigated how 99mTc-HMPAO changed in the blood and brain. The 99mTc-HMPAO, which was prepared by adding of 99mTcO4- to HMPAO and Sn(II), consisted of primary and secondary complexes, reduced hydrolyzed 99mTc, and 99mTc-pertechnetate. The percentage of the primary complex in 99mTc-HMPAO decreased with time after preparation. The primary complex converted to the secondary one very rapidly in the presence of plasma. When 99mTc-HMPAO was injected into patients, 99mTc activity was immediately partitioned in the plasma fraction, with approximately 60% in whole blood. In plasma, 99mTc was found to be associated with proteins such as albumin and globulin. 99mTc trapped in red cells was not washed out with either plasma or saline. Biodistribution studies showed that the less lipophilic compounds of 99mTc-HMPAO could not pass through the blood brain barrier (BBB), and therefore did not accumulate in the brain. The results of gel chromatography and equilibrium dialysis indicated that no specific 99mTc binding protein was present in the brain. Considering the instability of 99mTc-HMPAO in vivo, we proposed that the speed at which the primary complex converted to the less lipophilic compounds was important in allowing 99mTc-HMPAO to pass through the BBB and to be fixed in the brain.