运用HPLC-MS对鸦胆子油自微乳给药系统肠吸收的研究

目的:建立高效液相色谱-串联质谱法检测油酸和亚油酸含量的方法,从而对鸦胆子油自微乳给药系统中鸦胆子油的肠吸收进行研究.方法:以甲醇-水(95∶5 v/v)为流动相,流速为0.4 mL/min,柱温为35℃作为高效液相色谱的检测条件.利用大鼠小肠膜建立体外药物扩散体系研究鸦胆子油的肠吸收特性.结果:油酸和亚油酸的保留时间分别为10.46± 0.02和8.55±0.01 min,线性范围分别为0.50～50.0 ng/mL和5.06～101.2 ng/mL,平均绝对回收率分别为97.49±3.11％和105.76± 3.13％.日间和日内精密度都小于5％.在肠吸收实验中,鸦胆子油自微乳体系中测得油酸和亚油酸含量是单独给予鸦胆子油测得量的2.8和4.1倍.结论:该方法高效、灵敏、选择性高,可以用于鸦胆子油及鸦胆子油自微乳肠吸收中油酸和亚油酸的质量测定.     

离体外翻肠囊法研究白及提取物中6种成分的肠吸收特性

为研究白及提取物中4-(葡萄糖氧基)-肉桂酸葡萄糖氧基苄酯(B12)、2-异丁基苹果酸(B6)、1-[4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯(B17)、1,4-二[4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯(B14)、二氢菲1(B19)和1,4-二[4-(葡萄糖氧)苄基]-2-异丁基苹果酸酯-2-[4-O-肉桂酰基-6-O-乙酰基]葡萄糖苷(B23)6个成分在大鼠小肠中的吸收动力学特性。实验采用大鼠离体外翻肠囊模型考察各成分在不同浓度、不同肠段的吸收特性,建立超高效液相色谱-三重四极杆串联质谱联用仪(UPLC-MS/MS)法测定各成分含量,计算累计吸收量和吸收速率常数。结果表明,除B6成分的低浓度外,各成分在不同浓度、不同肠段下均表现为线性吸收,其回归相关系数(R)均达到0.9以上,符合一级吸收速率,且吸收速率常数随着浓度的增加而增加,提示各成分吸收机制为被动吸收;在同一浓度下不同肠段的总体吸收趋势为十二指肠的吸收要大于回肠、结肠和空肠。综上,白及提取物中6种成分在小肠中均有吸收,但小肠对各成分的吸收具有选择性。本研究可为白及提取物的药物临床开发,确定药物剂型方面提供了一定的实验参考。     

在体单向肠灌流模型研究白芷中三种成分的吸收特性

目的:研究白芷中有效成分欧前胡素、异欧前胡素和花椒毒酚在大鼠小肠各段的吸收特征。方法:采用大鼠在体单向肠灌流模型结合HPLC法同时测定肠灌流液中欧前胡素、异欧前胡素和花椒毒酚含量的变化,考察高、中、低三组剂量下三种成分在十二指肠、空肠和回肠的吸收特性。结果:三种成分随着剂量的增大,吸收速率常数(Ka)和有效渗透系数(Peff)逐渐增大。三种成分相同剂量下各肠段间吸收均无显著性差异,其吸收大小顺序为:欧前胡素异欧前胡素花椒毒酚。结论:白芷三种主要成分在各肠段均吸收良好,吸收大小呈剂量相关性。     

长春新碱阳离子纳米结构脂质载体及其小肠吸收的研究

目的:硫酸长春新碱作为一种细胞毒型抗肿瘤药物,临床上多用其注射剂,虽应用广泛,但存在较多缺点,如药物半衰期短,代谢速率快以及毒副作用明显。本文目的是制备包载长春新碱和十二烷基磺酸钠的阳离子纳米结构脂质载体,并对其进行评价。方法:用复乳挥发法制备出目标脂质纳米粒;利用激光粒度仪对其粒径及zeta电位进行检测;利用高效液相色谱法对其包封率和载药量进行测定;透析法检测纳米粒的体外释放行为;用小肠吸收法评价纳米粒的促进吸收作用。结果:制得的纳米粒的平均粒径为(192.4±4.14)nm,多分散系数(PDI)为0.184±0.015,包封率为32.28%,Zeta电位为(30.6±4.09)m V,载药量为(1.56±0.10)%;体外释放实验显示在pH=7.4的中性释放介质中,硫酸长春新碱脂质纳米粒表现出缓释特性;小肠吸收实验表明十二烷基磺酸钠的加入和阳离子纳米粒的修饰可提高小肠对药物的吸收。结论:阳离子硫酸长春新碱纳米结构脂质载体具有缓释效果,并可以促进小肠对药物的吸收。     

小肠锌吸收动力学模型的研究

用大鼠小肠研究了锌吸收动力学模型。分离空肠和迴肠,原位灌流硫酸锌溶液,采样测定灌流液中的锌含量;用二房室模型描述锌吸过程,计算肠腔和肠粘膜中锌移动的速率常数。比较了肠粘膜锌含量的理论值与实测值,对模型的合理性进行了检验;并用切除睾丸的大鼠测定了雄激素对小肠锌吸收动力学的影响,对模型的实用性进行了验证。结果表明:(1)用模型计算出的理论值与实测值相差不超过9％。说明模型基本合理:(2)此模型可以定量描述肠道锌吸收的动态过程,可对不同处理条件下的锌吸收动力学进行比较。     

硝普钠灌注对移植小肠粘膜细胞凋亡的影响

目的:探讨外源性一氧化氮(nitric oxide,NO)供体硝普钠(sodium nitroprusside,SNP)对移植小肠粘膜细胞凋亡的影响。方法:64只220～300g雄性SD大鼠随机分成3组:A1组(n=8),仅行剖腹关腹手术;A2组(n=12):12对大鼠随机作为供受体行同种异体节段小肠移植,无SNP干预;A3组(n=16):16对大鼠随机作为供受体行同种异体节段小肠移植,SNP加入灌注液进行供肠灌注。采用前述3组动物模型再灌注5小时肠造口标本,TUNEL法检测小肠蜡块标本的细胞凋亡情况。结果:与A1组(3.86±4.74%)相比,A2(22.44±10.94%)、A3组(17.12±8.44%)小肠粘膜的细胞凋亡指数均有显著增高(P<0.05),A3组较A2组细胞凋亡指数显著降低(P<0.05)。结论:小肠移植导致小肠粘膜细胞凋亡增加,外源性NO供体SNP灌注能够显著降低植入小肠的细胞凋亡,从而可能减弱粘膜屏障的损伤。     

法罗培南在大鼠肠道吸收部位的初步研究

目的:研究法罗培南在大鼠各肠段的吸收率,以确定最佳吸收部位,为制定合理的药物制剂提供科学依据.方法:采用大鼠在体肠循环法,各肠段区间如下:十二指肠段自幽门1cm处开始;空肠段离幽门15cm处开始;回肠段离盲肠上行20 cm处开始:结肠段从盲肠后段开始.各肠段取10 cm左右,将所取肠段两端开口、插管并结扎,插管与恒流泵连接.形成各自的回路.用HPLC法梯度洗脱测定法罗培南的浓度,依据药物在肠段中回流2小时后的减少量来确定各肠段法罗培南的吸收量.结果:法罗培南在大鼠各肠段吸收率平均值为十二指肠6.91±3.08%;空肠5.66±2.29%;回肠9.62±4.08%;结肠4.65±1.29%.稳定性实验、精密度实验、回收率实验的RSD分别为0.48%、0.234%和2.01%.结论:法罗培南在各肠段均有吸收,吸收率按回肠、十二指肠、空肠、结肠顺序依次降低.     

羊栖菜多糖抑脂沉积及其机制研究

目的研究羊栖菜多糖(SFPS)对秀丽隐杆线虫脂肪沉积的影响,并探讨其机制。方法用不同浓度SFPS配制NGM培养同步化秀丽隐杆线虫,经油红O染色后,裂解虫体,在490nm波长处测定吸光度值,同时采用外翻肠囊法,考察不同浓度SFPS被大鼠小肠吸收的情况。结果在含不同浓度SFPS配制的NGM培养基上生长的线虫,当SFPS浓度越高,线虫吸光度值越小,与对照组相比差异显著。在低剂量浓度下(0.6mg/ml),大鼠小肠对羊栖菜多糖吸收不明显。结论SFPS可减少动物体内脂质含量,其机制可能与小肠的吸收有关。     

普伐他汀对慢性心力衰竭患者血浆C-反应蛋白、N-末端脑钠素前体水平及心功能的影响

目的:探讨普伐他汀对慢性心力衰竭(CHF)患者血浆C-反应蛋白(CRP)、N-末端脑钠素前体(NT-proBNP)水平和心功能的影响.方法:将90例CHF患者随机分为对照组(38例)和普伐他汀组(52例),对照组给予强心、利尿、扩血管治疗,普伐他汀组在此基础上加用普伐他汀10mg.d-1,疗程12周.采用改良Simpson法测定心衰患者治疗前后左心室舒张末内径(LVEDD)、左心室射血分数(LVEF).免疫比浊法测定血清C-反应蛋白(CRP)水平.采用酶联免疫法血浆NT-proBNP水平的变化.结果:两组患者治疗后LVEF和LVEDD水平较治疗前均明显改善(p＜0.05);普伐他汀组LVEF由(36.2±3.5)%升至)45.6±4.8)%;血浆CRP浓度由(12.05+1.62)mg/L降至(6.43±1.35)mg/L;NT-proBNP浓度由(1198.7±312.2)fmol/ml降至(742.1±231.2)fmol/ml;TC由(5.60±0.63)mmol/L降至(4.03±0.41)mmol/L.与对照组比较差异均有统学意义(P＜0.05).且患者血浆NT-proBNP水平与LVEDD呈正相关(r=0.52,P＜0.05),而与LVEF存在负相关(r=-63,P＜0.05).结论:CHF患者加用普伐他汀短期治疗可进一步改善心功能,降低CRP和NT-proBNP水平.     

心肌样细胞移植对大鼠心肌梗死的疗效观察

目的观察心肌样细胞(CLC)移植对心肌梗死大鼠的疗效。方法制备大鼠心肌梗死动物模型,4周后超声检测大鼠血流动力学变化;体外分离、纯化大鼠骨髓间充质干细胞(BMSC),15 ng/ml的胰岛素样生长因子1(IGF-1)诱导BMSC分化为CLC 3,7,14和21 d,采用Western blot技术检测心肌标志性蛋白α-SMA,Ttroponin-T和Troponin-I的表达。CLC移植治疗心肌梗死大鼠,实验共分4组:心肌梗死组,生理盐水对照组,BMSC组及CLC组。移植治疗4周,超声检测血流动力学变化后取材大鼠心肌,冰冻切片,HE染色后检测大鼠心肌梗死的面积。统计分析采用单因素方差分析,实验组之间比较采用t检验。结果心肌梗死模型制备4周,模型组大鼠的LVSP数值为(118.74±11.56)mm Hg,低于假手术组(130.42±12.58)mm Hg,模型组大鼠的LVEDP数值为(14.29±7.63)mm Hg,高于假手术组(2.44±1.11)mm Hg,+dp/dt数值为(2645.17±468.16)mm Hg/s低于假手术组(4087.29±525.17)mm Hg/s,-dp/dt数值为(2487.80±348.21)mm Hg/s低于假手术组(3865.81±614.37)mm Hg/s,差异均具有统计学意义(P0.01)。IGF-1诱导BMSC 3,7,14和21d后均检测到α-SMA、Troponin-T和Troponin-I的表达,与第3天比较P0.01。移植治疗4周后发现生理盐水对照组大鼠血流动力学没有任何改变,BMSC组及CLC组大鼠的LVEDP数值分别为(9.15±4.54)mm Hg和(4.67±3.46)mm Hg,低于心肌梗死组(14.29±7.63)mm Hg,+dp/dt数值分别为(3245.45±368.76)mm Hg/s和(3612.78±468.54)mm Hg/s,高于心肌梗死组(2645.17±468.16)mm Hg/s,-dp/dt数值分别为(3014.11±412.12)mm Hg/s和(3347.21±398.56)mm Hg/s,高于假手术组(2487.80±348.21)mm Hg/s,同时CLC组大鼠的LVEDP(4.67±3.46)mm Hg低于BMSC组(9.15±4.54)mm Hg,±dp/dt数值分别是(3612.78±468.54)mm Hg/s和(3347.21±398.56)mm Hg/s高于BMSC组(3245.45±368.76)mm Hg/s和(3014.11±412.12)mm Hg/s,差异均具有统计学意义(P0.01)。BMSC组和CLC组的心梗面积与心肌梗死组比较明显减小,CLC组的梗死面积与BMSC组比较也明显减小,差异均具有统计学意义(P0.01)。结论 IGF-1诱导BMSC分化为CLC后移植治疗心肌梗死大鼠比单独移植BMSC疗效更好。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.