盐酸去氢骆驼蓬碱大鼠肠吸收动力学的研究

目的　研究盐酸去氢骆驼蓬碱在大鼠胃肠道各段的吸收动力学特征 ,为其剂型设计提供生物药剂学依据。方法　采用大鼠在体肠循环法分别研究盐酸去氢骆驼蓬碱在大鼠十二指肠、空肠、回肠及结肠中的吸收动力学特征。采用反相高效液相色谱法测定循环液中的药物浓度。结果　盐酸去氢骆驼蓬碱在十二指肠、空肠、回肠及结肠中的吸收速度常数Ka分别为 :( 0 .30 92± 0 .0 5 9) ,( 0 .2 0 6 4± 0 .0 4 4 ) ,( 0 .2 85 8± 0 .0 81) ,( 0 .2 0 0 9± 0 .0 80 )h-1。结论　盐酸去氢骆驼蓬碱在十二指肠、空肠、回肠及结肠中均能较好地吸收     

去氢骆驼蓬碱注射用乳剂的凝聚动力学研究

采用电导法对去氢骆驼蓬注射用乳剂的凝聚动力学进行了研究，求出凝聚速度方程和25℃时半凝聚期，从而定量地预测了这一分散体系的物理稳定性。     

主动载药法制备盐酸去氢骆驼蓬碱脂质体

目的制备高包封率的盐酸去氢骆驼蓬碱脂质体。方法处方前研究测定了药物在不同pH值缓冲液中的溶解度和表观油水分配系数;采用pH梯度进行主动载药。超滤法分离脂质体与游离药物,测定包封率,考察了外水相pH值、孵育温度、药脂比对包封率的影响。结果随pH值的增大,盐酸去氢骆驼蓬碱的溶解度降低,表观油水分配系数增大;采用主动载药法,包封率随脂质体内外相pH梯度的减少而降低,受孵育温度的影响不大,在药脂比小于1∶5时脂质体包封率达到80%以上。结论主动载药法可制得包封率较高的去氢骆驼蓬碱脂质体。     

盐酸去氢骆驼蓬碱血浆蛋白结合率的测定

目的:测定盐酸去氢骆驼蓬碱的血浆蛋白结合率.方法:采用超滤法和高效液相色谱法对盐酸去氢骆驼蓬碱的血浆蛋白结合率进行测定.结果:盐酸去氢骆驼蓬碱与小牛血清白蛋白、人血清白蛋白和正常人血浆的蛋白结合率分别为( 74.6 ± 9.8 )%、( 69.1 ± 8.7 )%、( 87.1 ± 5.3 )%.结论:盐酸去氢骆驼蓬碱与血浆蛋白具有中等强度的结合.     

Ultrastructural changes induced in HeLa cells after phototoxic treatment with harmine

In the present work, we have continued our studies on harmine phototoxicity in human tumour cells. The toxicity of harmine in the dark was analysed by a quantitative neutral red uptake assay, and subcellular sensitive targets following harmine photosensitization were de fi ned by electron microscopic analysis of HeLa cells. The results obtained indicated that this compound shows a clear dose-dependent cytotoxic effect in the dark. The combined treatment with suitable doses of harmine and UV radiation was very effective at an early stage, although maximal cell killing appeared 48 h after photodynamic activation. Ultrastructural examination of HeLa cells immediately after the photodynamic treatment revealed lysosomal destabilization and profound cytoplasmic vacuolization that evolved to cytolysis, which is typical of necrotic cell death. It is concluded that harmine could be a valuable photosensitizer whose biological applications merit further evaluation.     

骆驼蓬抗癌化学成分的分离鉴定和药理实验研究(附21例病人疗效观察)

在临床应用骆驼蓬制剂治疗消化道肿瘤等获得了一定效果的基础上,笔者从该植物种子内分离出两种生物硷单体。通过进行熔点、薄层、紫外、红外、核磁共振、质谱等方法测定,确认了其化学结构,即骆驼蓬硷(Harmaline)和去氢骆驼蓬硷(Harmine)。分别将这两种生物硷进行抗肿瘤试验,结果表明对小鼠肝癌、S—180、L_2等瘤株均有肯定的抑制作用。在体外用于处理人体宫颈癌(Hela)细胞,能明显地影响其生长。我们曾观察21例接受骆驼蓬总硷制剂(以上述两种生物硷为主要成分)治疗的恶性肿瘤病人,其有效率为85.7％。     

大鼠静脉注射和灌胃盐酸去氢骆驼蓬碱的药物动力学

目的 :研究盐酸去氢骆驼蓬碱胶囊在大鼠体内的药物动力学及其生物利用度。方法 :采用RP HPLC法测定大鼠予盐酸去氢骆驼蓬碱 10mg·kg-1,iv和 40mg·kg-1,ig后 8h内的血浆药物浓度。结果 :大鼠灌胃盐酸去氢骆驼蓬碱胶囊后血浆药物浓度在 0 2 3h左右达峰 (2 95 8g·mL-1) ,消除半衰期为 5 33h ,灌胃胶囊剂的生物利用度为 19 6 5 %。结论 :大鼠口服吸收盐酸去氢骆驼蓬碱迅速 ,但生物利用度较低     

盐酸骆驼蓬碱解离常数的等摩尔浓度分光光度法测定

根据等摩尔浓度分光光度法测定酸碱解离常数的原理 ,采用紫外分光光度法测定盐酸骆驼蓬碱的解离常数(p K a)。实验测得盐酸骆驼蓬碱的解离常数为 7.6 7± 0 .10 ,RSD1.30 %。方法结果可靠 ,方法简便     

The Down syndrome candidate dual-specificity tyrosine phosphorylation-regulated kinase 1A phosphorylates the neurodegeneration-related septin 4

The dual-specific kinase DYRK1A (dual-specificity tyrosine phosphorylation-regulated kinase 1A) is the mammalian orthologue of the Drosophila minibrain (MNB) protein kinase and executes diverse roles in neuronal development and adult brain physiology. DYRK1A is overexpressed in Down syndrome (DS) and has recently been implicated in several neurodegenerative diseases. In an attempt to elucidate the molecular basis of its involvement in cognitive and neurodegeneration processes, we searched for novel proteins interacting with the kinase domain of DYRK1A in the adult mouse brain and identified septin 4 (SEPT4, also known as Pnutl2/CDCrel-2). SEPT4 is a member of the group III septin family of guanosine triphosphate hydrolases (GTPases), which has previously been found in neurofibrillary tangles of Alzheimer disease brains and in alpha-synuclein-positive cytoplasmic inclusions in Parkinson disease brains. In transfected mammalian cells, DYRK1A specifically interacts with and phosphorylates SEPT4. Phosphorylation of SEPT4 by DYRK1A was inhibited by harmine, which has recently been identified as the most specific inhibitor of DYRK1A. In support of a physiological relation in the brain, we found that Dyrk1A and Sept4 are co-expressed and co-localized in neocortical neurons. These findings suggest that SEPT4 is a substrate of DYRK1A kinase and thus provide a possible link for the involvement of DYRK1A in neurodegenerative processes and in DS neuropathologies.     

Effect of DYRK1A activity inhibition on development of neuronal progenitors isolated from Ts65Dn mice

Overexpression of dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1A (DYRK1A), encoded by a gene located in the Down syndrome (DS) critical region, is considered a major contributor to developmental abnormalities in DS. DYRK1A regulates numerous genes involved in neuronal commitment, differentiation, maturation, and apoptosis. Because alterations of neurogenesis could lead to impaired brain development and mental retardation in individuals with DS, pharmacological normalization of DYRK1A activity has been postulated as DS therapy. We tested the effect of harmine, a specific DYRK1A inhibitor, on the development of neuronal progenitor cells (NPCs) isolated from the periventricular zone of newborn mice with segmental trisomy 16 (Ts65Dn mice), a mouse model for DS that overexpresses Dyrk1A by 1.5-fold. Trisomy did not affect the ability of NPCs to expand in culture. Twenty-four hours after stimulation of migration and neuronal differentiation, NPCs showed increased expression of Dyrk1A, particularly in the trisomic cultures. After 7 days, NPCs developed into a heterogeneous population of differentiating neurons and astrocytes that expressed Dyrk1A in the nuclei. In comparison with disomic cells, NPCs with trisomy showed premature neuronal differentiation and enhanced γ-aminobutyric acid (GABA)-ergic differentiation, but astrocyte development was unchanged. Harmine prevented premature neuronal maturation of trisomic NPCs but not acceleration of GABA-ergic development. In control NPCs, harmine treatment caused altered neuronal development of NPCs, similar to that in trisomic NPCs with Dyrk1A overexpression. This study suggests that pharmacological normalization of DYRK1A activity may have a potential role in DS therapy.