硫酸软骨素裂解酶发酵培养基的获得及发酵条件的优化

目的考察发酵培养基中碳源、氮源及无机盐等因素及各种发酵条件对温和气单孢菌YH311产硫酸软骨素裂解酶的影响,获得硫酸软骨素裂解酶最佳发酵培养基和发酵条件。方法采用单因素实验法、均匀设计法及正交设计法。结果获得的最优培养基配方(g·L-1)为:葡萄糖2 5 ,牛肉膏5 0 0 ,硫酸软骨素10 0 ,尿素0 5 ,MgSO4·7H2 O 9 0 ( pH 7 0 ) ;最适产酶条件为:2 % ( φ)种子液,2 8℃,2 0 0r·min-1,振荡通气培养2 4h。在优化条件下,硫酸软骨素裂解酶的产率可达110 0 0U·L-1。结论通过对发酵培养基及发酵条件的优化可将硫酸软骨素裂解酶的产量提高5倍。     

高产胞外硫酸软骨素酶菌株的筛选、鉴定及发酵条件优化

目的 对从青岛胶东海岸潮间带淤泥中分离筛选高产胞外硫酸软骨素酶的菌株进行鉴定和发酵条件优化。方法 通过平板快速筛选法和摇瓶复筛,筛选到1株高产胞外硫酸软骨素裂解酶的菌株C26,根据形态学和16S rRNA基因序列分析对其鉴定,并采用单因素实验和响应面实验对发酵条件进行优化。结果 根据形态学和16S rRNA基因序列分析,鉴定菌株C26为不动杆菌属（Acinetobacter sp.）,命名为Acinetobacter sp. C26。优化最适发酵条件为：硫酸软骨素15 g?L-1,酵母粉7.69 g?L-1,培养温度23 ℃,在最适条件下硫酸软骨素酶的活力可达11.96 U/mL,是优化前的4.82倍。结论 本研究筛选得到的菌株Acinetobacter sp. C26产酶活力高,发酵周期短,在生物化工及医药方面具有潜在应用价值。     

酶解高效液相色谱法测定硫酸软骨素的含量

目的建立酶解高效液相色谱法测定硫酸软骨素含量的方法。方法采用硫酸软骨素ABC酶制备样品,高效液相色谱法测定含量。以Ultimate XB-NH2柱(4.6 mm×25 cm,5μm)分离样品,醋酸钠缓冲液(pH 5.6)-乙腈(950∶50)为流动相,流速1.0 mL/min,检测波长232 nm,进样量10μL,柱温30℃。结果在此色谱条件下,硫酸软骨素A、B、C三组分分离良好;硫酸软骨素浓度在300～3 000μg/mL之间与峰面积呈良好线性关系;高、中、低三个浓度平均加样回收率为102.1%,100.4%和97.5%。结论本法简便、准确、可靠,可用于硫酸软骨素的含量测定。     

产硫酸软骨素酶菌株的筛选、鉴定及发酵条件优化

目的从土壤中分离筛选产硫酸软骨素酶活性较高的菌株,对目标菌株进行鉴定及发酵条件优化,分析其酶解产物。方法通过初筛及复筛筛选出1株高产硫酸软骨素酶菌株LHYM225,经形态学观察及16SrDNA序列测定并进行系统发育分析对其进行鉴定。利用单因素实验及正交实验对发酵培养基组分及发酵条件进行了优化。通过质谱法检测该酶的酶解产物。结论 16SrDNA序列分析表明菌株LHYM225与节杆菌属菌株(Arthrobacter)亲缘关系最近,将其初步鉴定为节杆菌属菌株(Arthrobacter sp.),该菌株的最佳发酵培养基:硫酸软骨素0.8%,KH2PO40.02%,酵母浸粉0.6%,MgSO4·7H2O...     

酶解液相色谱法测定硫酸软骨素钠含量

目的:建立酶解液相色谱法测定硫酸软骨素钠的含量。方法:使用硫酸软骨素ABC酶酶解硫酸软骨素钠,使用强阴离子交换高效液相色谱测定酶解产生的二糖,通过计算二糖峰面积总和确定硫酸软骨素钠的含量。色谱柱为Zorbax SAX(250 mm×4.6 mm,5μm);流动相为pH 3.5的水和pH 3.5的2 mol.L-1的氯化钠溶液,流速为1.0 mL.min-1,检测波长为232 nm,柱温为40℃。结果:硫酸软骨素钠的线性范围为0.25～1.50 mg.mL-1,r=0.9999;精密度RSD为0.3%;回收率为101.2%,RSD为1.6%(n=5);最低检测限为4.0μg.mL-1,定量限为11.9μg.mL-1。结论:该方法具有专属性好,灵敏度高,重现性好的优点。     

微生物硫酸软骨素裂解酶的研究进展

目的综述硫酸软骨素裂解酶的种类、分离纯化方法及药理学作用的研究进展。方法在检索国内外相关文献的基础上 ,对硫酸软骨素裂解酶的种类、分离纯化方法及药理学作用进行整理和归纳。结果硫酸软骨素裂解酶具有 4种类型 ;硫酸软骨素裂解酶可作为工具酶及药用酶用于基础理论及药学领域的研究中。结论作为工具酶和药用酶 ,硫酸软骨素裂解酶在科研及医药领域拥有广阔的发展前景。     

二氢嘧啶酶产生菌培养条件的研究

目的确定二氢嘧啶酶产生菌的最适培养条件。方法采用Plackett Burman法设计和球面对称设计联用。结果最适培养基组成为 (% ,W /V) ;酵母膏 2 .39,葡萄糖 1.81,尿嘧啶 0 .0 6 ,K2 HPO4 ·3H2 O 0 .2 ,MgCl2 ·6H2 O 0 .0 5 ,NaCl 0 .3,pH7.2～ 7.4。 32℃ ,2 2 0r/min振荡培养 10h ,每 1ml培养液酶活力为 3 .0 2U。 结论得到了二氢嘧啶酶产生菌最佳培养条件。     

养殖鲟鱼软骨中硫酸软骨素的优化提取工艺研究

目的以养殖鲟鱼软骨为原料,提取硫酸软骨素、筛选提取工艺条件。方法用稀碱-盐解-酶解法提取硫酸软骨素,并对各工艺中影响提取效果的不同因素进行正交实验。结果碱提取最佳工艺组合为:碱浓度5%,料液比1∶6,碱提取时间3h;盐解最佳工艺组合为:盐浓度4%,盐解温度90℃,盐解时间20min;酶解最佳工艺组合为:酶浓度0.4%,酶解温度52℃,酶解时间2.5h。结论采用上述组合提取硫酸软骨素的得率为31.56%,显著高于(P<0.05)传统工艺的25.86%。     

豆豉纤溶酶产生菌发酵条件研究

对从豆豉中筛选到的一株纤溶酶产生菌--枯草芽孢杆菌HGD107进行发酵产酶条件研究.在最适发酵条件下,该菌株产豆豉纤溶酶酶活达到尿激酶3643u/ml发酵液.     

海洋细菌Thalassomonas sp.LD5中新型褐藻胶裂解酶TsAly7C的研究

目的对来源于Thalassomonas sp.LD5的褐藻胶裂解酶TsAly7C进行研究,以期获得具有优良性质的褐藻胶裂解酶,适应工业需求。方法在生物信息学分析的基础上,对TsAly7C进行了重组表达和酶学性质研究。结果通过生物信息学分析,TsAly7C属于PL7家族的第一亚家族。对重组TsAly7C(r TsAly7C)酶学性质进行分析,r TsAly7C的最适温度是30℃,最适p H为8.0(Na₂HPO₄-NaH₂PO₄缓冲液),在底物中添加300 mmol/L NaCl时降解能力最强。r TsAly7C的p H稳定性和温度稳定性较好,在0～30℃保存1 h仍保有80%以上的酶活,是1种适低温性褐藻胶裂解酶。Cu²⁺、Co²⁺、Zn²⁺、Ni²⁺和十二烷基硫酸钠(SDS)对r TsAly7C的酶活有明显的抑制作用。r TsAly7C是1种双功能褐藻胶裂解酶,以内切形式裂解褐藻胶产生不饱和二糖和单糖。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.