利用亚硝酸诱变原生质体筛选L—亮氨酸高产菌株的研究

本实验以Ｌ－亮氨酸产生菌黄色短杆菌ＣＦＮ－１９为出发菌株。我们首先对ＣＦＮ－１９菌株制备原生质体，原生质体制备率为９５．１％，再生率为２５％，然后对原生质体进行亚硝酸、利福平、氯化锂复合诱变处理，从再生菌株中筛选出一株高产菌株Ｈ６－６６，产酸量由原来的２３．１ｍｇ／ｍｌ提高到３２．６ｍｇ／ｍｌ，提高率达４１％。同时又对Ｈ６－６６菌株进行遗传稳定性考察，考察结果Ｈ６－６６菌株是高产稳定菌株。     

马山前胡化学成分研究

从广西特有的前胡属植物马山前胡Peucedanum mashanense Shan et Sheh根中首次分得10个化合物晶体，经理化常数和波谱解析，分别鉴定为3′(R)-( )-亥茅酚（1）、3′（S）－（－）－亥茅酚（2）、印度枸桔素（3）、石防风素（4）、珊瑚菜素（5）、水合氧化前胡素（6）、佛手柑内酯（7）、β－谷甾醇（8）、褐煤酸（9）和甘露醇（10），其中化合物1为一个新天然产物。     

胀果甘草根中胀果皂甙Ⅱ和Ⅵ的结构鉴定

从胀果甘草（Glycyrrhiza inflata Bat.）根的10％乙醇浸出物中分得七个新三萜皂甙，依理化性质及波谱分析，其中二个的结构分别鉴定为：甘草次酸－3－O－β－D－6‘‘－乙基－吡喃葡萄糖醛酸基－（1→2）-β-D－6‘－正丁基吡喃葡萄糖醛酸甙（1）和甘草次酸－3－O－β－D－6‘‘－正丁基－吡喃葡萄糖醛酸基－（1→2)-β-D-6‘-乙基－吡喃葡萄糖醛酸甙（2），分别命名为胀果皂甙Ⅱ和Ⅵ。     

546株病原菌的耐药性监测分析

目的：调查临床分离的菌耐药现状，指导临床用药。方法：对2000年1－12月住院患者送检标本中分离的546株病原菌以K－B法行药物敏感测定。结果：革兰阳性球菌占24．9％，革兰阴性杆菌占71．1％。在革兰阴性球菌中，金黄色葡萄球菌（SA）占33．1％，凝固酶阴性葡萄球菌（CNS0占47．8％，耐甲氧西林金黄色葡萄球菌（MRSA）57．8％，耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）69．2％。在革兰阴性杆菌中大肠埃希菌中首位35．3％，其余依次为克雷伯菌属16．5％，铜绿假单胞菌15．5％，不动杆菌8．8％，肠杆菌属6．7％。SA对红霉素、氨苄西林及复方磺胺甲恶唑耐药率较高，分别为80％，88％，100％。在革兰阴性杆菌中除肠杆菌属均头孢3代有阿米卡星的耐药率低于50％，但对氨苄西林的耐药性均较高63．6％－100％。结论：在检出的致病菌仍以革兰阴性杆菌为主，出现多重耐药菌株。革兰阳性球菌呈上升趋势，特别是MRSA及MRCNS。应根据药敏结果选用抗生素。     

6种β—内酰胺类抗生素对G^—杆菌的PAE特点

目的 对比研究6种β－内酰胺类抗菌药物泰宁（TIN）、卡贝宁（CBN）、哌拉西林（PIP）、美洛西林（MZL）、头孢哌酮（CPZ）和头孢地嗪（CDZM）对2种G^-杆菌大肠埃希氏菌和绿脓假单胞菌的抗生素后效应（PAE）。方法 采用AVANTAGE全自动分析仪，应用光密度法测定PAE。结果与结论 美洛西林对大肠埃希氏菌的PAE为负值或零，对绿脓假单胞菌的PAE很小，仅在4MIC时PAE达1h左右；哌拉西林对大肠埃希氏菌和绿脓假单胞菌的PAE均很小，即使在4MIC时PAE也仅有0.3h左右。在4MIC以下时，PAE与浓度依赖性不甚明显。头孢哌酮和头孢地嗪除了在4MIC时对大肠埃希氏菌的PAE可达1h外，其余PAE均很短，甚至没有，但随着抗菌药物浓度的增加，PAE显增加（P＜0．05），呈现部分浓度依赖性，提示在较高浓度下可望产生相对明显的PAE。一般β－内酰胺类抗菌药物对G^-杆菌PAE较小，而泰宁和卡贝宁则较长。泰宁和卡贝宁的PAE要显长于其它4种抗菌药物（P＜0．05），两药对大肠埃希氏菌和绿脓假单胞菌的PAE产可达到1－3h，同时卡贝宁的PAE要显长于泰宁。即使在1倍MIC时，PAE亦显长于其它4种药物，而在4倍MIC时则更长。两药对G^-杆菌的PAE在1／2至4倍MIC浓度间呈显的浓度依赖性。提示泰宁和卡贝宁可能具有与其它β^-内酰胺类抗菌药物不同的PAE产生机理。     

利用亚硝酸诱变原生质体筛选L-亮氨酸高产菌株的研究

本实验以L-亮氨酸产生菌黄色短杆菌CFN-19为出发菌株。我们首先对CFN-19菌株制备原生质体,原生质体制备率为95.1%,再生率为25%,然后对原生质体进行亚硝酸、利福平、氯化锂复合诱变处理,从再生菌株中筛选出一株高产菌株H_(6-66),产酸量由原来的23.1mg/ml提高到32.6mg/ml,提高率达41%.同时又对H_(6-66)菌株进行遗传稳定性考察,考察结果H_(6-66)菌株是高产稳定菌株。     

重症监护病房中革兰氏阴性杆菌的耐药性分析

目的：调查我院重症监护病房革兰氏阴性杆菌耐药状况，了解超广谱β－内酰胺酶（ESBLs)菌株的发生率。方法：用E试验法测定100株革兰氏阴性杆菌对12种抗生素的最低抑菌浓度（MIC）。结果：亚胺培南、ertapenem(MK-0826)和阿米卡星对所有受试菌保持较高抗菌活性，细菌耐药率分别为4％、15％和17％；头孢他啶、头孢吡肟、头孢哌酮／舒巴坦耐药率分别为33％、25％和26％，其他抗生素耐药率在44％－51％。与2001年我院调查水平相比，头孢哌酮／舒巴坦耐药率增加15％，其他抗生素耐药率变化不大。用头孢噻肟／头孢噻肟＋克拉维酸和头孢他啶／头孢他啶＋克拉维酸分别筛选出ESBLs产生菌13株和11株，其中大肠埃希氏菌产酶率最高，分别为21．7％（5／23）和34．8％（8／23），肺炎克雷伯氏菌其次，分别为23．8％（5／21）和9．5％（2／21）。抗菌活性最强的是亚胺培南，对所有大肠埃希氏菌和肺炎克雷伯氏菌ESBLs菌株都敏感。而临床常用的头孢哌酮／舒巴坦和替卡西林／克拉维酸并未体现酶抑制剂优越性，耐药菌株多。结论：亚胺培南抑菌率最高，对ESBLs产生菌有较强的抗菌活性，而加酶抑制剂抗生素的滥用，已造成细菌对其耐药率升高，且对付产酶耐药株感染逐渐失去优势。     

仙人掌中的两个新酚性羧酸酯

从仙人掌块茎中分得二个新酚性羟酸酯和六个已知化合物。根据其理化性质和波谱学方法鉴定它们的结构为2－（4－羟基－苄基－）苹果到－4－正丁酯（1）－2－（4－羟基－苄基）－苹果酸－4－甲酯（2），2－（4－羟基－苄基）－苹果酸（3），蒲公英萜醇－3－乙酸酯（4），软木三萜酮（5），羽扇豆－3－酮（6），亚油酸甲酯（7）和油酸甲酯（8），其中（1）和（2）为新化合物，（3），（4），（6），（7）和（8）为首的次从仙人掌中分得。     

PCR-SSCP技术直接快速检测痰标本中结核分支杆菌rpoB,katG,ahpC基因突变的研究

目的：应用PCR－SSCP技术直接快速检测痰标本中结核分支杆菌rpoB,katG及ahpC基因突变,评价此方法用于结核分杆菌利福平（RFP）及异烟肼（INH）耐药性试验的意义。方法：以结核分支杆菌H37Rv为对照,30例耐RFP（单耐或多耐）、21例耐INH（单耐和多耐）的结核分枝杆菌临床分离株及10例敏感菌株;39例菌阳肺结核患者及30例非结核 性肺部疾病患者痰标本,采用PCR－SS－CP技术检测痰标本和菌株中的结核杆菌rpoB,katG,ahpC基因突变,并与药敏试验对照。结果：PCR－SSCP检测痰标本中结核分支杆菌rpoB,katG及ahpC基因突变的阳性率分别为79％（31／39）、46％（18／39）及5％（2／39）.结论：PCR－SSCP可望成为直接检测临床痰标本中结核分枝杆菌耐利福平及耐异烟肼的快速方法。     

1-[2-(N-甲基)氨基-2-(2,4-二氯苯基)乙基]-1H-1,2,4-三唑化合物的合成

目的：改进1－[2-（N－甲基）氨基－2－（2,4－二氯苯基）乙基]-1H-1,2,4-三唑的合成方法,降低成本,提高收率,方法：以2－氯－1－（2,4－二氯苯基）乙酮为原料,经三唑烷基化与甲胺反应生成酮亚胺后还原（A法）,或与N－甲基甲酰胺进行Leukart反应（B法）,结果：A和B两种方法制得目标化合物的收率分别为57．6％和63．2％。结论：A和B两种方法原料易得,反应简便,降低了成本,提高了收率。     

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.     

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.     

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.