盒子草氨基酸和糖类成分分析

本文通过对盒子草氨基酸和糖类成分分析,结果表明：总氨基酸含量为１１．３３％,其中人体必需氨基酸为４．９１％,碱性氨基酸为１．８３％,中性氨基酸为６．８２％,酸性氨基酸为２．６８％。总糖含量为１３．１３％,其中多糖为５．２９％,低聚糖为４．６８％,还原糖为３．１６％。     

无视异绒螨产卵对不同土壤含水量的选择性观察

试验结果表明,除含水量为5％和17.5％的土壤外,无视异绒螨在含水量为7.5％～15％的范围内均可产卵,其中以含水量为12.5％的土壤产卵量最高,与其它土样之间存在着显著性差异。根据聚类分析结果,可将供试的土样分为3个类型,即最适产卵型(土壤含水量为12.5％)、适宜产卵型(土壤水量为7.5％～10％)和不宜产卵型(土壤含水量为5％、15％和17.5％)。     

用中性红标记酵母原生质体初探

用２％蜗牛酶处理酵母细胞６０分钟,啤酒酵母Ｙ２９的原生质体形成率为９０％,再生率为９．５％;糖化酵母ＩＢ的原生质体形成率为８６％,再生率为１２％。用５００ｐｐｍ中性红染液对Ｙ２９菌株的整细胞和原生质体染色１５分钟,细胞的着色率为８４％,存活率为１２％,而原生质体的着色率为７５％,再生率为６．４％,经染色后的原生质体体积缩小,在交变电场中排队所需的场强电降低。     

浩浩巴花粉生活力测定简报

用10％、20％、30％蔗糖溶液加琼脂作培养基,在恒温箱中培养浩浩巴花粉,在20％蔗糖溶液培养基中,花粉发芽率为26.5％;贮藏34天后,花粉发芽率为0.77％,基本失去发芽能力。在培养基中加入0.01％硼砂,花粉发芽率为61.6％,比不加硼砂的培养基花粉发芽率提高了35.1％。     

浩浩巴花粉生活力测定简报

用10％、20％、30％蔗糖溶液加琼脂作培养基,在恒温箱中培养浩浩巴花粉,在20％蔗糖溶液培养基中,花粉发芽率为26.5％;贮藏34天后,花粉发芽率为0.77％,基本失去发芽能力。在培养基中加入0.01％硼砂,花粉发芽率为61.6％,比不加硼砂的培养基花粉发芽率提高了35.1％。     

原位生物技术对城市重污染河道底泥的治理效果

以扬州市典型城市内河河道为例研究了人工曝气、生态砖覆盖、生物填料覆盖、低位植物浮床(简称低位浮床)等原位生态处理技术对河道底泥污染释放及其对上覆水污染负荷贡献的治理效果.研究结果表明:经不同原位生态处理后,1)底泥中氨氮的释放速率下降50.3％-89.64％,平均为59.27％;底泥污染释放对上覆水氨氮负荷贡献量的去除率为36.59％-82.67％,平均为53.33％;2)底泥中总氮的释放速率下降20.96％-88.94％,平均为42.32％;底泥总氮释放对上覆水污染负荷贡献量的污染去除率为38.00％-67.06％,平均为54.96％;3)底泥中总磷的释放速率下降27.49％-91.00％,平均为55.31％;底泥总磷释放对上覆水总磷污染负荷贡献量的去除率为67.14％-98.46％,平均为84.33％;4)底泥中CODMn的释放速率下降11.84％-79.32％,平均为41.16％;底泥上覆水中CODMn的释放速率下降-1.25％--70.74％,平均为29.83％.研究还发现,原位生态处理技术在运行中对底泥污染治理的效果受该技术对底泥的扰动程度的影响,在进行集成应用的时候,对底泥扰动较大的技术应与对底泥扰动较小的技术相间应用,以减少工程技术运行中对底泥扰动造成的污染爆发式释放,达到更好的整体处理效果.     

生境异质性对刺五加种子萌发的影响及其种子库动态

本文通过定位观测研究了中国东北红松阔叶林及其次生林下重要灌木刺五加种子在异质生境中转化为幼苗的差异,人工落叶松林下模拟种子库的动态。结果表明：人工落叶松林下的转化率最高,为１６．８％。以下顺序为蒙古栎林下为４．ｌ％,白桦林下为２．７％,人工红松林下为０．８％,硬阔叶林下为０．５％。人工落叶松林下模拟种子库中刺五加种子的寿命为４ａ。幼苗输出率第２年为１４．５％,第３年为１０．１％,第４年为１．８％。其它输出为：腐烂３３．ｌ％;生理衰老２２．３％;鼠类捕食１４．１％,但其很不稳定,这与鼠类种群数量动态有关。昆虫和土壤动物捕食最少,仅１．２７％。     

家兔早期胚胎的活力测定

本文报告了用0.04％中性红及0.125％台盼蓝液测定家兔早期胚胎的活力,染色后着为浅粉色者为可发育胚胎,其培养回收发育率为68％和90％;移植发育率为100％。着为蓝、紫色者为不发育胚胎。     

电视纵隔镜与CT 对胸部疾病诊断的运用研究

目的:探讨电视纵隔镜与CT对胸部疾病诊断中的运用.方法:对我院收治的59例胸部疑难疾病患者采用CT以及电视纵隔镜检查,并对两种方法对肺癌纵膈淋巴转移的诊断效果进行比较.结果:所有患者采用纵隔镜检查其确诊率为100％,CT诊断诊断符合率为525％;CT对肺癌纵隔淋巴结转移的灵敏度为55.26％、真实性为57.89％、特异度为60.53％、阳性预测值为44.74％以及阴性预测值为81.58％,而电视纵隔镜其分别为94.74％、97.37％、100.00％、100.00％、97.37％.电视纵隔镜在诊断肺癌纵膈淋巴结转移的各项指标中均优于CT.结论:电视纵隔镜对胸部疑难疾病具有较好的诊断效果,而且其具有并发症少等特点.     

扁蓄总黄酮含量的测定

以35％乙醇为提取溶剂,聚酰胺吸附提纯,芦丁为标准品,用分光光度法于510nm处测定了扁蓄各部位的总黄酮含量。结果表明：扁蓄全草总黄酮含量为4．349％,根为7．115％,茎为5．454％,叶为3．544％。     

Histochemical observations on uptake of L-dopa into endocrine cells of the rat pituitary gland during the postnatal development

The uptake of L-dopa into the cells of the adenohypophysis of the rat was studied during the postnatal development and at adult age using the formaldehyde-induced fluorescence method (FIF). The cells taking up L-dopa were classified by Alcian blue-PAS-Orange G staining. The correlation between the cells taking up L-dopa and those containing tryptophyl-peptide was estimated during the postnatal period and in adult rats. The cells containing tryptophyl-peptide were demonstrated using fluorescence induced by treatment with combined formaldehyde and acetyl chloride vapour. The following observations were made: 1) Great majority of the cells taking up L-dopa did not contain tryptophyl-peptide. Thus the accumulation of L-dopa into the cells of pars distalis is not due to accumulation of L-dopa into the cells by the same transport mechanism as the amino acids for tryptophyl-peptide. 2) Of the cells taking up L-dopa in the adult rats 96% were chromophobes, 2.0% acidophilic cells (somatotrophs and cells producing prolactin), 0.9% R-mucoid cells (corticotrophs), and 1.2% S1- and S2-mucoid cells (gonadotrophs and thyrotrophs). At 10 and 25 days' age the relative numbers of the cells taking up L-dopa were about the same. 3) Pretreatment with nialamide caused only a slight increase in the number of the cells taking up L-dopa. The decrease in the number of the cells uptaking L-dopa of the pars distalis, which takes place after 5 weeks' age is thus not caused by the increased MAO-activity. 4) Strongly chromophilic cells did not take up L-dopa. At the light of our results it seems evident that L-dopa is taken up by the chromophobic cells when these differentiate into chromophilic cells. The accumulation of L-dopa may be a sign of an active transport of amino acids into the cells. The accumulation of L-dopa into the chromophobic stellate and follicular cells may reflect their metabolic activity. These cells probably have an important role in the production of the hormones of the pars distalis.     

Effects of L-dopa treatment on methylation in mouse brain: implications for the side effects of L-dopa

The effects of L-dopa on methylation process in the mouse brain were investigated. The study is based on recent findings that methylation may play an important role in Parkinson's disease (PD) and in the actions of L-dopa. The methyl donor, S-adenosylmethionine (SAM) and a product of SAM, methyl beta-carboline, were shown to cause PD-like symptoms, when injected into the brain of animals. Furthermore, large amounts of 3-O-methyl dopa, the methyl product of L-dopa, are produced in PD patients receiving L-dopa treatment, and L-dopa induces methionine adenosyl transferase, the enzyme that produces SAM. The results show that, at 0.5 hr, L-dopa (100 mg/kg) decreased the methyl donor, S-adenosylmethionine (SAM) by 36%, increased its metabolite S-adenosylhomocysteine (SAH) by 89% and increased methylation (SAH/SAM) by about 200%. All parameters returned to control values within 4 hr. But 2, 3 and 4 consecutive injections of L-dopa, given at 45 min intervals, depleted SAM by 60, 64 and 76% and increased SAM/SAH to 818, 896, and 1524%. L-dopa (50, 100 and 200 mg/kg) dose-dependently depleted SAM from 24.9 +/- 1.7 nmol/g to 13.0 +/- 0.8, 14.7 +/- 0.8 and 7.7 +/- 0.7 nmol/g, and increased SAH from 1.88 +/- 0.14 to 3.43 +/- 0.26, 4.22 +/- 0.32 and 6.21 +/- 0.40 nmol/g. Brain L-dopa was increased to 326, 335 and 779%, dopamine to 138, 116 and 217% and SAH/SAM to 354, 392 and 1101%. The data show that L-dopa depletes SAM, and increases methylation 4-5 times more than dopamine, therefore, methylation may play a role in the actions of L-dopa. This and other studies suggest that the high level of utilization of methyl group by L-dopa leads to the induction of enzymes to replenish SAM and to increase the methylation of L-dopa as well as DA. These changes may be involved in the side effects of L-dopa.     

The effects of L-dopa on the activity of methionine adenosyltransferase: Relevance to L-dopa therapy and tolerance

L-dopa, the major treatment for Parkinson's disease (PD), depletes S-adenosyl-L-methionine (SAM). Since SAM causes PD-like symptoms in rodents, the decreased efficacy of chronic L-dopa administered to PD patients may result from a rebound increase in SAM via methionine adenosyl transferase (MAT), which produces SAM from methionine and ATP. This was tested by administering intraperitoneally saline, or L-dopa to mice and assaying for brain MAT activity. As compared to controls, L-dopa (100 mg/kg) treatments of 1 and 2 times per day for 4 days did not significantly increase MAT activity. However, treatments of 1 and 2 times per day for 4 and 8 days did significantly increase the activity of MAT by 21.38% and 28.37%, respectively. These results show that short interval, chronic L-dopa treatments significantly increases MAT activity, which increases the production of SAM. SAM may physiologically antagonize the effects of L-dopa and biochemically decrease the concentrations of L-dopa and dopamine. Thus, an increase in MAT may be related to the decreased efficacy of chronic L-dopa therapy in PD.     

The effect of ferrous sulfate and pH on L-dopa absorption

Ferrous sulfate decreases L-dopa bioavailability in humans probably as a result of binding of L-dopa by iron in the gastrointestinal tract. This study was conducted to determine if iron by binding L-dopa decreases L-dopa absorption and to investigate the effect of different pH buffers on intestinal absorption of L-dopa in the presence and absence of ferrous sulfate. A rat model developed to examine drug absorption was used. Control animals had buffered [14C]L-dopa solutions injected into two in vivo closed segments of intestine; a 5-cm duodenal and a 5-cm proximal jejunal segment. These studies were conducted using solutions buffered at pH 5.5, 6.5, 7.5, and 8.5. An identical procedure was followed for experimental animals except ferrous sulfate was injected with the buffered L-dopa solutions. Ferrous sulfate resulted in a reduction in L-dopa absorption in the buffers at all pHs in both the duodenum and jejunum. The average reduction in L-dopa absorption in the presence of iron was 22.6% in the duodenum and 23.9% in the jejunum. There was a tendency for ferrous sulfate to cause a greater reduction in L-dopa absorption as the buffer pH increased. There was also a decrease in L-dopa absorption in the higher pH buffers in the absence of iron. Despite this latter result, in the jejunum there was an increase in the percent reduction in L-dopa absorption associated with ferrous sulfate as pH increased. Although this tendency was not as consistent in the duodenum as the jejunum, the combined results are compatible with the chemical model of increased L-dopa--iron binding as pH increases.     

Determination of cabergoline and L-dopa in human plasma using liquid chromatography-tandem mass spectrometry

We determined cabergoline and L-dopa in human plasma using liquid chromatography-mass spectrometry with tandem mass spectrometry (LC-MS-MS). The deproteinized plasma samples with organic solvent or acid were analyzed directly by reversed-phase liquid chromatography. Using multiple reaction monitoring (MRM, product ions m/z 381 of m/z 452 for cabergoline and m/z 152 of m/z 198 for L-dopa) on LC-MS-MS with electrospray ionization (ESI), cabergoline and L-dopa in human plasma were determined. Calibration curves of the method showed a good linearity in the range 5-250 pg/ml for cabergoline and 1-200 ng/ml for L-dopa, respectively. The limit of determination was estimated to be approximately 2 pg/ml for cabergoline and approximately 0.1 ng/ml for L-dopa, respectively. The method was applied to the analysis of cabergoline and L-dopa in plasma samples from patients treated with these drugs. The precision of analysis showed coefficients of variation ranging from 3.8% to 10.5% at cabergoline concentration of 13.8-26.2 pg/ml and from 2.9% to 8.9% at an L-dopa concentration of 302.5-522.1 ng/ml in patient plasma. As a result, the procedure proved to be very suitable for routine analysis.     

发酵法生产左旋多巴提取工艺的研究

<正> 前文[1]对嗜麦芽假单胞菌生产左旋多巴发酵条件进行了研究,为了从发酵液中获得纯净产品,本文对左旋多巴的提取工艺进行了研究。我们采取乙酸乙酯去杂质法、粉末状活性炭脱色法、颗粒状活性炭柱法、HD—I型树脂脱色法来提取左旋多巴,经过比较,认为活性炭脱色法效果较好,采用该法提取左旋多巴,回收率达64%,并获得针形及块状结晶。     

Effects of dopamine metabolites on locomotor activities and on the binding of dopamine: relevance to the side effects of L-dopa

L-dopa is the major treatment for Parkinson's disease (PD), but its efficacy is limited by the presence of dyskinesia. The dyskinesia develops over a period of exposure to L-dopa and is related to the dosage, therefore, the cause may involve inductive changes that produce toxic levels of metabolites, interfering with dopamine (DA) neurotransmission. Chronic L-dopa induces catechol-O-methyltransferase (COMT) and methionine adenosyl transferase (MAT), enzymes involved in the methylation of catecholamines (CA). In addition, high levels of 3-O-methyl-dopa have been reported in the plasma of dyskinetic PD patients, treated with L-dopa, as compared to non-dyskinetic patients, therefore, the methyl metabolites of CA may be increased during L-dopa therapy and may be involved in the dyskinesia. Since large amounts of DA are produced from L-dopa, and DA is extensively methylated, the methyl metabolites of DA, 3-methoxytyramine (3-MT) and 3,4-dimethoxyphenylethylamine (DIMPEA), may be also involved. The first step in knowing this, is to assess the behavioral and DA-receptor activities of 3-MT and DIMPEA. In the rat, the intraventricular injection of 0.5 micromol of DIMPEA increased the total distance traveled (TD) by over 100%, the number of movement (NM) made by 40% and the time spent moving (MT) by about 36%. Identical doses of 3-MT decreased the TD by 42%, NM by 22% and MT by 39%. DIMPEA (1 mM) increased the binding of DA with brain membranes by 44.7%, whereas 3-MT decreased it by 15.8%. The results show that 3-MT and DIMPEA are behaviorally active, and in parallel, they interact with the binding sites for DA, consequently, they may contribute to the side effects of L-dopa. L-dopa produces high levels of DA and induces MAT and COMT. It is proposed, therefore, that DA will be methylated to 3-MT and 3-MT to DIMPEA. At threshold level each product will inhibit, allosterically, its enzyme of methylation, causing sequential and rhythmic up and down regulation of its concentration. At peak levels these hydrophobic metabolites will modulate the actions of DA on synaptic membranes, causing abnormal movements, at times, resembling the "on-off effects".     

Controlled clinical trial of L-dopa and nafoxidine in advanced breast cancer: an E.O.R.T.C. study.

L-Dopa lowers plasma prolactin levels, and there have been reports that patients with advanced breast cancer have been successfully treated with L-dopa. To test the potential value of L-dopa in this disease a randomized clinical trial of L-dopa and nafoxidine (as the reference compound) was conducted in postmenopausal women with advanced breast cancer. Objective remissions were obtained in sever out of 36 patients (19%) treated with nafoxidine but in none out of 40 patients treated with L-dopa. L-Dopa in the dose schedule used seems to be ineffective in advanced breast cancer.     

Mediated exodus of L-dopa from human epidermal Langerhans cells

Summary. L-3,4-dihydroxyphenylalanine (L-dopa) is not metabolized within human epidermal Langerhans cells (LC); yet they can take up substantial amounts of this amino acid which subsequently can be released into the extracellular space. We recently reported that human epidermal energy metabolism is predominantly anaerobic and that the influx mechanism is a unidirectional L-dopa/proton counter-transport system and now we describe conditions for the mediated transport of L-dopa out of the LC. It is demonstrated that certain amino acids and one dipeptide can effectively trigger the efflux of L-dopa taken up by the LC.Thus, -methyl-dopa (-m-dopa), D-dopa and the dipeptide, met–ala at the outside of the plasma membrane stimulated the efflux of L-dopa from L-dopa loaded LC. Similar effects were achieved by a variety of other amino acids in the extracellular fluid while some other amino acids were inactive. The time required for 50% D-methionine-induced exodus of L-dopa from L-dopa loaded LC was in the range of 5–7min and a complete exodus of L-dopa was attained at about 20min of incubation. This dislocation of L-dopa to the extracellular fluid is interpreted as an expression of trans-stimulation. In the case of -m-dopa, D-dopa and met–ala, which admittedly were not able to penetrate the plasma membrane of LC, the concept of trans-stimulation was given a new purport, since none of them were able to participate in an exchange reaction. Finally, it could be concluded that L-dopa escaped by a route different from the one responsible for L-dopa uptake in LC.Thus, while the influx of L-dopa supports extrusion of protons deriving from anaerobic glycolysis in the LC, L-dopa efflux can provide the cells with useful amino acids in an energy-saving way, altogether a remarkable biological process. From this follows that L-dopa has a biological function of its own, besides being a precursor in the catecholamine and pigment syntheses.     

A Comparison Between Melanotic and Amelanotic Retinal Pigment Epithelial Cells In Vitro Concerning the Effects of L-Dopa and Oxygen on Cell Cycle

Melanin precursors and free radicals, cytotoxic substances, are produced during melanin synthesis by tyrosinase. We compared these cytotoxic effects of L-dopa and oxygen on the cell cycle of melanotic retinal pigment epithelial (RPE) cells with amelanotic RPE cells because of the differences of tyrosinase activities between melanotic and amelanotic RPE cells. Flow cytometric DNA analysis of RPE cells exposed to L-dopa (100 μM and 250 μM) were conducted at several oxygen concentrations (20%, 10%, and 5%). The dose-dependent effect of L-dopa to arrest the cell cycle (the S phase) was more pronounced in melanotic than in amelanotic RPE cells, and oxygen caused arrest in the G₁ phase.