Gigantiform cementoma showing apparent activity on a bone scan

A bone scan in a Negroid female suspected of myeloma showed no uptake other than in the jaws. A panoramic radiograph revealed multiple mixed-density lesions, in particular in the mandible, suggestive of gigantiform cementoma. The significance of this association is discussed.     

Partial inhibition of proteasome activity enhances remyelination after cuprizone-induced demyelination

We have previously demonstrated that addition of low concentrations of lactacystin (a specific inhibitor of the proteasome) to oligodendroglial cell cultures containing a high percentage of precursor cells induces their exit from the cell cycle and their differentiation. On the other hand, we have recently shown that the mechanism of cuprizone toxicity on oligodendroglial cells involves the recruitment of microglia and their secretion of pro-inflammatory cytokines and in the increased production of oxidant species, which results in a decrease in the activities of the mitochondrial respiratory chain. In the present paper we investigated the effect of a decrease in proteasome activity induced by the injection of lactacystin in the corpus callosum in the remyelination process that normally occurs after cuprizone-induced demyelination. This treatment markedly improves the remyelination process that normally occurs in cuprizone-induced demyelination. It also attenuates the activation of NFκB and the recruitment of microglia and astrocytes, thus helping in the recovery of the mitochondrial respiratory chain activities that are affected by cuprizone treatment.     

In vitro cultivation of Plasmodium cynomolgi bastianelli in hepatocytes of the Macaca rhesus

Primary cultures of Rhesus monkey were infected with sporozoites of P. c. bastianelli. Despite a high level of contamination, two schizonts were seen at days 6 and 11.     

不同学历医学生的心理状况及对自杀态度：整群随机抽样调查

目的:不同学历层次医学生心理状况及对自杀态度可能不同,比较中专、大专、本科学历医学生的心理状况、对自杀的态度及自杀倾向的差异。方法:①于2005-01/2006-12对河北省3所医学院校在校生920名进行问卷调查,包括本科、大专、中专3个层次。以教学班为单位,在每个层次内选取3个班级为调查样本。②应用症状自评量表、自杀态度调查问卷进行问卷调查。症状自评量表评估学生心理健康状况,此量表包括躯体化、强迫、人际关系敏感、抑郁、焦虑、敌对、恐怖、偏执、精神病及其他10个因子90个条目。每个条目均为1￣5级评分,评分越高表明症状的频度和程度越重。因子分≥2者归为筛查阳性组;因子分≥3者有中度及以上心理问题。③自杀态度调查问卷包括对自杀行为性质的态度、对自杀者的态度、对自杀者家属的态度和对安乐死的态度4个维度29个条目,采用5级评分。问卷评分≤2.5分认为对自杀持肯定、认可、宽容、理解的态度,2.5￣3.5分为矛盾或中立态度,≥3.5认为对自杀持反对、否定、排斥、歧视态度。以症状自评量表的第15项"想结束自己的生命"为判断自杀意念有无的依据,以其评分的等级(从无、轻度、中度、偏重、严重)评定自杀意念的严重程度。④采用χ2检验对数据进行统计分析。结果:发放问卷920份,收回合格问卷863份,有效率93.8%。①心理状况:在中专生、大专生、本科生心理问题筛查阳性率分别为47.9%,40.9%,36.4%,有中度及以上心理问题分别占18.2%,15.9%,13.6%。在心理问题筛查阳性和中度及以上心理问题方面,不同学历医学生在躯体化、人际关系敏感、焦虑、敌对、恐怖、偏执、精神病性方面所占比例比较,差异有显著性意义(χ2=6.11￣15.78,P<0.05￣0.01)。②对自杀行为的态度:医学生对自杀行为的性质多持矛盾或中立态度,对自杀者的态度、自杀者家属的态度和安乐死的态度多持肯定或理解的态度。在对自杀行为性质的态度上持矛盾或中立态度者大专学生多于其他两组(χ2=7.35,P<0.05),持否定或歧视态度者本科生多于其他两组(χ2=11.21,P<0.01);在对自杀者的态度上持肯定或理解态度者以本科学生居多(χ2=6.51,P<0.05),持矛盾或中立态度者以大专学生为多,中专生次之,本科生最少(χ2=10.89,P<0.01);在对自杀者家属的态度上持肯定或理解、矛盾或中立态度者本科学生多于其他两组(χ2=7.71,8.76,P<0.05);在对安乐死的态度上持肯定或理解态度者大专学生多于其他两组(χ2=12.01,P<0.01),持矛盾或中立态度者以大专学生为多,本科生次之,中专生最少(χ2=16.47,P<0.01),持否定或歧视态度者,中专学生多于其他两组(χ2=6.24,P<0.05)。③自杀意念:自杀意念出现率随学历的增高有下降的趋势,中专生、大专生、本科生自杀意念出现率分别为35.5%,15.3%,13.3%,3者比较,差异有显著性意义(χ2=49.546,P<0.01),而3组间偏重和严重自杀意念者的差异不明显(P>0.05)。结论:在3个学历层次中,中专生出现心理问题和自杀意念者最多;医学生对自杀的态度存在学历差异。     

转化生长因子β1在白细胞介素1β诱导大鼠肾小管上皮细胞转分化及大黄素干预中的作用

目的:大黄素对白细胞介素1β诱导NRK52E细胞转分化有显著抑制作用。实验拟进一步观察转化生长因子β1在白细胞介素1β诱导大鼠肾小管上皮细胞-肌成纤维细胞转分化及大黄素抑制作用中的意义。方法:实验于2006-10/2007-05在泸州医学院附属医院免疫实验室完成。⑴实验材料及分组:以培养的大鼠肾小管上皮细胞株(NRK52E)为观察对象,按如下分组分别添加不同处理因素:①对照组:仅加入体积分数为0.05小牛血清的高糖DMEM培养基。②白细胞介素1β诱导组:加含白细胞介素1β终浓度为10μg/L的高糖DMEM培养基。③SB431542阻断组:加含白细胞介素1β终浓度为10μg/L及SB431542终浓度为10μmol/L的高糖DMEM培养基。④白细胞介素1β 大黄素组:同时加分别含白细胞介素1β终浓度为10μg/L及大黄素终浓度为25mg/L的高糖DMEM培养基。⑵实验评估:培养48h后用倒置相差显微镜观察细胞形态,细胞免疫化学染色法检测肌酸激酶、α-平滑肌肌动蛋白及转化生长因子β1的表达。结果:①白细胞介素1β可诱导部分细胞由卵圆形转变为梭形,且肌酸激酶表达减弱(P<0.01),α-平滑肌肌动蛋白及转化生长因子β1表达显著增强(P<0.01)。②SB431542特异性抑制转化生长因子β1作用后,白细胞介素1β诱导的细胞形态改变受抑,同时肌酸激酶表达增强(P<0.01),α-平滑肌肌动蛋白表达减弱(P<0.01),但转化生长因子β1的表达却无明显变化。③大黄素对白细胞介素1β诱导的细胞形态改变及肌酸激酶、α-平滑肌肌动蛋白的表达有明显抑制作用,其抑制作用与SB431542的作用相比无显著差异;同时,大黄素对白细胞介素1β诱导的转化生长因子β1的表达也有明显抑制作用(P<0.01)。结论:转化生长因子β1可能介导了白细胞介素1β诱导大鼠肾小管上皮细胞-肌成纤维细胞转分化,并参与了大黄素抑制白细胞介素1β诱导大鼠肾小管上皮细胞转分化的作用。     

In Vitro Antimalarial Activity of a New Organometallic Analog, Ferrocene-Chloroquine

The in vitro activities of new organometallic chloroquine analogs, based on 4-amino-quinoleine compounds bound to a molecule of ferrocene, were evaluated against chloroquine-susceptible, chloroquine-intermediate, and chloroquine-resistant, culture-adapted Plasmodium falciparum lineages by a proliferation test. One of the ferrocene analogs totally restored the activity of chloroquine against chloroquine-resistant parasites. This compound, associated with tartaric acid for better solubility, was highly effective. The role of the ferrocene in reversing chloroquine resistance is discussed, as is its potential use for human therapy.     

构建以少突胶质细胞前体为主与人类早产儿脑室周围白质软化病理相似的动物模型

目的:建立以晚期少突胶质细胞前体为主、与人类早产儿脑室周围白质软化病理相似的可靠动物模型。方法:实验于2005-10/2006-06在上海交通大学医学院附属新华医院科研中心完成。2d龄和7d龄SD同窝清洁级新生大鼠各43只,雌雄不拘,以随机数字表法分为4组,即2d龄模型组(n=25)、2d龄假手术组(n=18)、7d龄模型组(n=25)和7d龄假手术组(n=18),脑室周围白质软化动物模型建立:结扎双侧颈总动脉,手术时间短于10～15min,术后将新生大鼠送入缺氧箱缺氧30min,混合气体为体积分数0.08的O2和0.92的N2,输入流量为1～2.5mL/min。假手术组游离双侧颈总动脉,但不予结扎和缺氧。将各组大鼠分别于术后1d测定脑梗死体积,术后2d进行少突胶质细胞系列免疫组织化学染色分析、脑片TTC染色观察脑梗死情况以及光镜下脑病理研究,术后21d进行电镜下病理研究。结果:实验86只新生大鼠,14只制作脑室周围白质软化模型死亡,余72只计入统计。①术后1d各组脑片大体观察:模型组脑内呈现大面积白色梗死区,多为大脑前、中动脉供血区域,2,7d龄模型组梗死体积分别为(53.45±33.90),(68.78±20.22)mm3,梗死百分比分别为(24.98±15.44)%,(11.84±4.14)%;假手术组脑片颜色鲜红,未见白色梗死区。②新生大鼠少突胶质细胞系列标志物免疫组织化学结果:2d龄新生大鼠脑白质内以少突胶质细胞前体为主,7d龄新生大鼠则以成熟少突胶质细胞为主。模型大鼠的相应少突胶质细胞系列阳性标记物的积分吸光度值均显著低于同日龄对照新生大鼠(P<0.05～0.01)。③各组大鼠术后2d光镜下脑病理检查结果:2d龄模型组新生大鼠的脑室周围以及皮层下白质呈现囊性坏死和细胞凋亡,而皮质神经元损伤轻微;而7d龄模型组在白质和皮质部位均呈明显损伤。④术后21d电镜下各组幼鼠脑病理检查结果:2d龄模型组幼鼠的脑白质内未见髓鞘形成,7d龄模型组幼鼠中见少量髓鞘形成,而同日龄假手术对照幼鼠的脑白质内则髓鞘形成正常。结论:通过对2d龄新生大鼠双侧颈总动脉结扎伴缺氧30min缺氧缺血法创建的脑室周围白质软化新生大鼠模型中存在少突胶质细胞前体和少突胶质细胞的明显受损和丢失,成功建立了2d龄新生大鼠以少突胶质细胞前体为主、与人类早产儿脑室周围白质软化病理相似的脑室周围白质软化动物模型。     

白藜芦醇对动物离体心房收缩力和心率作用的种属差异性比较

目的:观察白藜芦醇对豚鼠、小鼠和家兔离体心肌收缩力和心率的影响。方法:实验于2005-08/2006-12在河北医科大学西校区实验中心完成。①实验分组:离体豚鼠、小鼠和家兔心肌各分为9组:空白对照组、溶剂对照组、递增累积浓度白藜芦醇组(浓度为10-6,3×10-6,10-5,3×10-5,10-4,3×10-4mol/L),白藜芦醇对照组(5×10-5mol/L),ATP敏感性钾通道阻断剂格列苯脲(5×10-5mol/L)预孵育 白藜芦醇组,钙激活钾通道阻断剂四乙胺(10-3mol/L)预孵育 白藜芦醇组,电压依赖性钾通道阻断剂4-氨基吡啶(10-3mol/L)预孵育 白藜芦醇组,内向整流钾通道阻断剂氯化钡(10-4mol/L)预孵育 白藜芦醇组,乙酰胆碱调节钾通道阻断剂阿托品(10-5mol/L)预孵育 白藜芦醇组。②实验方法:不同类型的钾通道阻断剂均预孵育15min后,分别加入白藜芦醇(终浓度为5×10-5mol/L),连续记录30min,与相应动物白藜芦醇对照组相比较。③评估指标:分析不同阻断剂与白藜芦醇联用对心房收缩力下降率及心率抑制率的影响。结果:①白藜芦醇可降低豚鼠和小鼠离体心肌收缩力和心率(P<0.05),并被ATP敏感性钾通道阻断剂格列苯脲和钙激活钾通道阻断剂四乙胺部分阻断。②白藜芦醇可降低家兔离体心肌心率,格列苯脲可阻断白藜芦醇的负性变时作用。③电压依赖性钾通道阻断剂4-氨基吡啶、内向整流钾通道阻断剂氯化钡、乙酰胆碱调节钾通道阻断剂阿托品均不能阻断白藜芦醇对3种不同动物离体心房收缩力和心率的作用(P>0.05)。结论:白藜芦醇可呈剂量依赖性减慢豚鼠、小鼠和家兔的心率,白藜芦醇可减弱豚鼠心肌收缩力,其作用是与开放ATP敏感性钾通道有关,而与电压依赖性钾通道、内向整流钾通道和乙酰胆碱调节钾通道无关。同时,钙激活钾通道也参与了白藜芦醇对豚鼠和小鼠离体心房收缩力和/或心率的抑制作用。白藜芦醇对离体心肌收缩力和心率的作用有种属差异性。     

Structure and biosynthesis of heat-stable antifungal factor (HSAF), a broad-spectrum antimycotic with a novel mode of action

A screen for antifungal compounds from Lysobacter enzymogenes strain C3, a bacterial biological control agent of fungal diseases, has previously led to the isolation of heat-stable antifungal factor (HSAF). HSAF exhibits inhibitory activities against a wide range of fungal species and shows a novel mode of antifungal action by disrupting the biosynthesis of a distinct group of sphingolipids. We have now determined the chemical structure of HSAF, which is identical to that of dihydromaltophilin, an antifungal metabolite with a unique macrocyclic lactam system containing a tetramic acid moiety and a 5,5,6-tricyclic skeleton. We have also identified the genetic locus responsible for the biosynthesis of HSAF in strain C3. DNA sequencing of this locus revealed genes for a hybrid polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS), a sterol desaturase, a ferredoxin reductase, and an arginase. The disruption of the PKS-NRPS gene generated C3 mutants that lost the ability to produce HSAF and to inhibit fungal growth, demonstrating a hybrid PKS-NRPS that catalyzed the biosynthesis of the unique macrolactam system that is found in many biologically active natural products isolated from marine organisms. In addition, we have generated mutants with disrupted sterol desaturase, ferredoxin reductase, and arginase and examined the metabolites produced in these mutants. The work represents the first study of the genetic basis for the biosynthesis of the tetramic acid-containing macrolactams. The elucidation of the chemical structure of HSAF and the identification of the genetic locus for its biosynthesis establish the foundation for future exploitation of this group of compounds as new fungicides or antifungal drugs.