单增李斯特菌胎盘感染的体内外模型研究进展

单核细胞增生李斯特氏菌（Listeria monocytogenes）是重要的食源性致病菌,能引发人类的李斯特菌病,是全球公共卫生问题之一。该菌易感染孕妇,引起胎儿和新生儿的侵袭性李斯特菌病,严重威胁母婴健康。因此,建立有效的单增李斯特菌感染胎盘体内外模型,解析和探究单增李斯特菌经胎盘感染机制,是预防和控制单增李斯特菌感染母婴的关键所在。本文综述了可用于研究单增李斯特菌母婴感染的体内外胎盘模型,总结和讨论了各类模型的优势和局限性;并着重分析了体外三维胎盘屏障模型在单增李斯特菌感染方面的研究进展和未来研究方向。以期为深入解析该菌经胎盘感染的途径、发病机制提供支持,并为预防和控制母婴李斯特菌病提供科学参考。     

黄芩苷对嗜水气单胞菌生物膜形成的影响及体内外的抑菌作用

[目的]探讨中药单体黄芩苷对嗜水气单胞菌在体内外生长及生物膜形成的影响.[方法]体外实验中,利用牛津杯法检测抑菌圈直径,结晶紫法检测生物膜的形成,通过泳动实验检测黄芩苷对嗜水气单胞菌运动性的影响,紫外吸收法检测细胞膜完整性,用透射电镜技术观察黄芩苷对细菌形态的影响.体内实验利用草鱼为对象检测黄芩苷对嗜水气单胞菌增殖的影...     

猴面包树的离体快繁条件筛选

该文以猴面包树(Adansonia digitata)种子为外植体,首先筛选合适的种子预处理及消毒方法,然后经过启动培养获得无菌外植体后在增殖培养基中进行丛生芽诱导,将丛生芽切成单株进行生根壮苗培养,最终建立猴面包树离体快繁技术体系.结果表明:75％酒精浸泡3 min+0.1％升汞消毒15 min消毒效果较佳,污染率为...     

睡菜离体快繁技术的研究

以睡菜的幼嫩茎段为外植体,接种到附加不同浓度激素配比(6-BA/NAA)的MS培养基,诱导睡菜愈伤组织、芽及根的生长。研究发现,外植体在1.0mg/L 6-BA+0.1mg/L NAA+MS的培养基上培养10d,可观察到浅绿色的愈伤组织。愈伤组织转接到4.0mg/L 6-BA+0.3mg/L NAA+MS培养基上2周左右可生成芽。对带芽的愈伤组织再进行诱导生根进而形成完整再生植株,最适根诱导培养基为0.3mg/L 6-BA+1.0mg/L NAA+MS培养基。该实验采用植物离体快繁技术成功建立了睡菜再生体系,为睡菜种苗规模化奠定了技术基础。     

狭叶薰衣草的离体培养及挥发性成分的分析

为建立新疆狭叶薰衣草(Lavandula angustifolia)的快速繁殖体系,以种子、茎、叶为外植体,对种子萌发、愈伤组织诱导、丛芽分化和生根的最适培养条件进行了研究;用水蒸气蒸馏法提取狭叶薰衣草挥发油,采用气相色谱-质谱法测定挥发油成分。结果表明,种子浸泡的适宜时间为6 h,切开种皮培养,出芽时间最少为6 d;诱导种子出芽的适宜培养基为MS+6-BA2 mg/L;以茎为外植体诱导愈伤组织效果较好,适宜培养基为MS+6-BA 2 mg/L+2,4-D 1 mg/L;诱导分化丛芽的适宜培养基为MS+6-BA 1 mg/L+NAA 0.5 mg/L;生根的适宜培养基为1/2MS+NAA 1 mg/L+6-BA 0.5 mg/L;盆栽薰衣草和无菌苗薰衣草的挥发油主要成分相差较大,离体培养的薰衣草的主要挥发性成分有叶绿醇、丁香油烃、氧化石竹烯等。     

六角果鸢尾离体快繁技术体系的构建

为构建六角果鸢尾(Iris hexagona)的离体快繁体系,以其幼嫩根状茎为外植体,研究了培养基和植物生长调节剂对不定芽诱导、增殖和植株生根的影响。结果表明,根状茎用0.1%Hg Cl2消毒13 min的效果较佳;不定芽诱导最适培养基为MS+6-BA 1.5 mg L–1+NAA 0.5 mg L–1+蔗糖30 g L–1+琼脂7.5 g L–1,不定芽增殖的适宜培养基为MS+6-BA 0.5 mg L–1+NAA0.2 mg L–1+KT 0.3 mg L–1+蔗糖30 g L–1+琼脂7.5 g L–1;在MS+IBA 1.5 mg L–1+蔗糖30 g L–1+琼脂7.5 g L–1培养基上不定芽生根率可达100%;腐殖土和珍珠岩+泥炭土+蛭石(1∶2∶1)均可作为组培苗移栽的适宜基质,移栽成活率可达100%。     

常规培养与缺氧条件下BCG菌体内外sRNA的表达检测

近期发现细菌的sRNA在菌体内和菌体外均具有一定的生物学功能.为研究结核分枝杆菌菌体内外sRNA的表达情况,通过分析卡介苗(Bacillus Calmette-Guerin Vaccine,BCG)菌体和外泌体RNA测序结果,采用RT-qPCR法检测常规培养与缺氧条件下BCG菌体内外sRNA相对表达量,分析菌体内外sR...     

酸枣果提取物在体内外对抗生素的增效作用及机制研究

作者研究团队先前从酸枣果的氯仿提取物中精制得到其低极性范围的活性组合物Fr.2a,发现Fr.2a与多种抗生素联用显示出广泛的协同抗菌作用。该研究在Fr.2a的基础上利用硅胶柱层析对酸枣果氯仿提取物中其他极性范围内的活性成分进行了分离纯化,得到精制物Fr.B,并对精制物Fr.B进行GC MS、核磁共振氢谱、红外光谱分析,以确定Fr.B的组成成分;通过抗菌谱分析和细胞通透性分析,以明确Fr.B的抗菌增效谱和抗菌增效机制;采用熔和法将精制物Fr.B制备成软膏,通过小鼠伤口感染模型评价该软膏对抗生素的增效效果。结果表明：(1)由酸枣果氯仿提取物进一步精制得到的Fr.B组分,主要包含反油酸、油酸、顺 10 十六碳烯醇、棕榈酸等脂肪酸类化合物。(2)Fr.B分别与庆大霉素、妥布霉素、氨苄青霉素、氯霉素、红霉素、夫西地酸、制霉菌素、酮康唑和两性霉素B等多种抗生素联用时显示出广泛的协同抗菌作用。(3)Fr.B可破坏细胞膜和细胞壁的完整性而增强细菌细胞的通透性。(4)在体内和体外Fr.B均能显著增强红霉素对耐甲氧西林金黄色葡萄球菌(MRSA)的杀菌作用,从而提高红霉素对MRSA菌株引起的伤口感染的治疗效果。研究表明,本研究所得到的Fr.B具有广谱的抗菌增效活性,能够增强红霉素对伤口耐药菌感染的治疗效果。该研究结果为克服微生物对抗生素的耐药性提供了新的思路和解决方案。     

巴西橡胶树HbMyb1基因的原位PCR物理定位

为探讨巴西橡胶树(Hevea brasiliensis)死皮病抗性相关HbMyb1基因的定位,采用所建立的橡胶树染色体原位PCR技术体系进行研究。结果表明,HbMyb1基因初步定位于巴西橡胶树‘热研7-33-97’的第5号染色体长臂上,信号位点到着丝粒的百分距离为15.21,并观察到在巴西橡胶树‘热研7-33-97’叶片细胞核的不同分裂时期均扩增到1~2个信号。同时对染色体标本的制备、保存、预处理等方面进行了探讨。     

Schistosoma mansoni: Schistosomicidal effect of mefloquine and primaquine in vitro

We investigated the effects of the anti-malarials mefloquine and primaquine against the juvenile and adult life stages of Schistosoma mansoniin vitro. Cercariae were incubated with 0.5 μg/ml, 1 μg/ml and 2 μg/ml mefloquine or primaquine and with 1 μg/ml praziquantel for 12 h. Schistosomula, pre-adults and adults were incubated with 0.5 μg/ml, 1 μg/ml and 2 μg/ml mefloquine or primaquine and with 1 μg/ml praziquantel for 7 days. The viability status was classified as viable, damaged or dead and was checked every 3 h for cercariae and every 12 h for schistosomula, pre-adults and adults. Both, mefloquine and primaquine show time and dose-dependent schistosomicidal effects on the four life stages of S. mansoni. The promising in vitro effects on all stages of the blood fluke S. mansoni warrants further evaluation of both anti-malarials and their derivatives for their prophylactic and therapeutic values in early and late schistosomiasis in field trials.     

Keratan sulfate and related murine glycosylation can suppress murine cartilage damage in vitro and in vivo

Keratan sulfate (KS) proteoglycan side chains are abundant in the human cartilage matrix, but these chains have been said to be absent in murine skeletal tissues. We previously showed that KS suppresses cartilage damage and ameliorates inflammation in mice arthritis model. Because mice deficient of N-acetylglucosamine 6-O-sulfotransferase-1 (GlcNAc6ST-1) (KS biosynthesis enzyme) are now available, we decided to do further examinations.We examined, in culture, the difference between GlcNAc6ST-1^−/− and wild-type (WT) mice for interleukin (IL)-1α-induced glycosaminoglycan (GAG) release from the articular cartilage. Arthritis was induced by intravenous administration of an anti-type II collagen antibody cocktail and subsequent intraperitoneal injection of lipopolysaccharide. We examined the differences in arthritis severities in the two genotypes. After intraperitoneal KS administration in phosphate-buffered saline (PBS) or PBS alone, we evaluated the potential of KS in ameliorating arthritis and protecting against cartilage damage in deficient mice.GAG release induced by IL-1α in the explants, and severity of arthritis were greater in GlcNAc6ST-1^−/− mice than their WT littermates. Intraperitoneal KS administration effectively suppressed arthritis induction in GlcNAc6ST-1^−/− mice. Thus, GlcNAc6ST-1^−/− mice cartilage is more fragile than WT mice cartilage, and exogenous KS can suppress arthritis induction in GlcNAc6ST-1^−/− mice. Vestigial KS chain or altered glycosylation in articular cartilage in GlcNAc6ST-1^−/− mice may be protective against arthritis and associated cartilage damage as well as cartilage damage in culture. KS may offer therapeutic opportunities for chondroprotection and suppression of joint damage in inflammatory arthritis and may become a therapeutic agent for treating rheumatoid arthritis.     

原位PCR技术及其应用前景

原位PCR是分子生物学领域中一种崭新的技术,它结合了PCR技术和原位杂交技术的优点.该文介绍了原位PCR技术的起源、发展及方法学,并简要描述了该技术的应用现状及前景．     

基于荧光原位杂交的藜属植物核型分析

为精确地识别藜属植物染色体组的核型特征,该文研究了4种来自青海高原的野生藜属植物(灰绿藜、藜、菊叶香藜及杂配藜)和1种从美国引进的栽培藜麦品种PI614932-HX(3)基于染色体荧光原位杂交(rDNA FISH)的核型。利用5S rDNA和45S rDNA对5种藜属植物有丝分裂中期的染色体进行FISH研究。藜属植物的核型分析结果表明:(1)藜属植物中存在二倍体(2n=2x=18)和四倍体(2n=4x=36)两种倍性,藜麦和灰绿藜为四倍体,其余3种为二倍体。(2)藜麦、灰绿藜、藜、菊叶香藜及杂配藜的核型公式分别为2n=4x=36=34m(2AST)+2sm,2n=4x=36=32m(4AST)+4sm,2n=2x=18=16m(4AST)+2sm,2n=2x=18=18m及2n=2x=18=16m+2sm。(3)染色体由大部分的中部着丝粒染色体(m)和少部分近中部着丝粒染色体(sm)组成。(4)核型类型除了菊叶香藜为1B以外,其余均属于2B类型。(5)在藜麦、灰绿藜及藜中具有分布位置不同、数量不等的双随体。5S rDNA、45S rDNA FISH结果表明:(1)藜麦和灰绿藜的染色体上存在2对5S rDNA位点和1对45S rDNA位点,藜、杂配藜的染色体上存在1对5S rDNA位点和1对45S rDNA位点,菊叶香藜的染色体上只存在1对5S rDNA位点。(2)5S rDNA和45S rDNA位点均位于染色体的短臂上。该研究首次获得了藜属植物基于5S rDNA和45S rDNA荧光原位杂交核型,为藜属植物亲缘关系研究和细胞生物学研究提供了分子细胞遗传学依据。     

无距虾脊兰花粉离体萌发及储藏条件的研究

以天目山野生无距虾脊兰的花粉为材料,采用离体萌发法研究了花粉的储藏性以及不同的培养基组分和培养条件对花粉萌发和花粉管生长的影响,并采用联苯胺-过氧化氢法测定了其柱头的可授性,以筛选无距虾脊兰花粉的培养方法以及储藏条件,为其种质资源保存等研究奠定基础。结果表明:(1)无距虾脊兰最适花粉液体培养基为200g·L-1蔗糖+50mg·L-1 H3BO3+40mg·L-1 Ca(NO3)2·4H2O,并且在pH 5.5~6.0、温度25℃恒温下培养48h,无距虾脊兰花粉萌发率(81.71%)和花粉管生长(247.42μm)最佳。(2)无距虾脊兰花粉在-80℃中低温干燥储藏360d后仍具有48.58%的萌发率。(3)无距虾脊兰的柱头在开花前5d内均具有可授性,花粉块在整个花期内均保持了28.96%~81.71%的生活力,但柱头可授性和花粉活力均随开花后时间的延长显著降低。     

Relationship between in vivo synchronicity of Plasmodium falciparum and allelic diversity

Plasmodium falciparum cells tend to grow in synchronicity during their cyclic intraerythrocytic development in vivo. Both host and parasite factors appear to be involved in this synchronization. We examined the link between mixed-allelic-family P. falciparum infection and synchronicity in parasitized red blood cells (PRBC) from symptomatic children.The distribution of rings and trophozoites in each PRBC sample was determined by standard microscopy. P. falciparum was genotyped by using a polymerase chain reaction (PCR) targeting three loci (merozoite surface proteins (MSP) 1 and 2, and 175-kD erythrocyte binding antigen (EBA), allowing us to distinguish parasite clones belonging to a single-allelic family (SAF) and those belonging to a mixed-allelic family (MAF). Parasite development was considered synchronous when peripheral blood contained at least 95% of rings or 95% of trophozoites.Parasite development was synchronous in 22 (21.2%) of the 104 children studied. Twenty (90.9%) of these infections were SAF and two (9.1%) were MAF. Rings and trophozoites predominated in respectively 12 (60%) and 8 (40%) SAF infections. Respectively 17.1% and 82.9% of the 82 asynchronous cases corresponded to SAF and MAF infection. Parasite synchronicity was therefore significantly related to single-allelic-family infection (p < 2 × 10^− 10).Twenty different MSP-1 alleles and thirteen different MSP-2 alleles were identified. Only three isolates from patients with SAF infection comprised a single allele or genotype, the other isolates harboring at least two alleles. The mean number of alleles or clones was respectively 3.0 and 10.0 in SAF and MAF infection. These results reflect the allelic diversity of the MSP loci and show that SAF infection can correspond to multiple parasite clones (or genotypes) but, in general, fewer than in MAF infection (p ≤ 0.0007).These results confirm the extensive polymorphism of P. falciparum vaccine candidates MSP-1 and -2 in southeastern Gabon and demonstrate that parasite synchronicity in vivo is strongly associated with single-allelic-family infection.     

肉苁蓉人工控制离体寄生关键技术研究

以梭梭无菌苗和肉苁蓉萌发种子为材料,对肉苁蓉离体寄生培养基质、离体寄生方式和离体寄生环境条件等进行了研究,以明确肉苁蓉的寄生特性,为肉苁蓉人工繁殖技术体系的建立与优化奠定基础。结果表明:玻璃纤维滤纸是肉苁蓉离体寄生适宜的培养基质;在黑暗、相对湿度80%、温度18℃～30℃的环境中,萌发的肉苁蓉种子与寄主梭梭寄生培养8d后开始建立寄生关系,寄生率达82%;而光照条件下,萌发的肉苁蓉种子与梭梭不能建立寄生关系。     

多糖类益生元的筛选及凝结芽孢杆菌体外发酵特性北大核心

【目的】探究9种多糖对凝结芽孢杆菌(Bacillus coagulans)的增殖、产酶特性的影响。【方法】将凝结芽孢杆菌分别添加至菊粉多糖(inulin polysaccharide)、刺五加多糖(Eleutherococcus senticosus polysaccharide)、壳寡糖(chitosan oligosaccharide)、防风多糖(Saposhnikovia divaricata polysaccharide)、低聚木糖(xylo-oligosaccharide)、黄芪多糖(Astragalus polysaccharide)、甘露糖(D-mannose)、白术多糖(Atractylodes macrocephala Koidz polysaccharide)和玉屏风多糖(Yu Ping Feng polysaccharide)为唯一碳源的培养基中,通过菌株生长、酶活性及其体外厌氧发酵等作为指标,筛选出最优益生元。【结果】凝结芽孢杆菌能很好地利用防风多糖、黄芪多糖、白术多糖和玉屏风多糖;添加量为4%的防风多糖和白术多糖,pH差值差异最大,蛋白酶活性差异显著(P<0.05)。体外发酵乳酸活性和总蛋白酶活性均提高,4%白术多糖的乳酸和总蛋白酶活性差异显著(P<0.05);肠道内容物发酵液16S rRNA基因高通量测序结果表明,与对照组比较,添加黄芪多糖、防风多糖、甘露糖3种益生元发酵凝结芽孢杆菌显著降低了气单胞菌(Aeromonas)、α-变形菌(α-Proteobacteria)、链球菌(Streptococcus)、志贺氏杆菌属(Shigella)等致病菌的相对丰度,提高了乳杆菌(Lactobacillus)、厚壁菌门(Firmicutes)、乳酸乳球菌(Lactococcus lactis)、产酸杆菌(Acidobacteria)的相对丰度。【结论】凝结芽孢杆菌发酵4%白术多糖具有较好的产酶性能与益生特性,二者协同发酵添加至饲料中具有较好的发展潜力。     

The in vivo distribution of Cr-labeled Trypanosoma cruzi in mice

The optimal conditions for labeling Trypanosoma cruzi culture forms with ⁵¹CrO₄²⁻ were determined. Labeled trypanosomes or labeled human red blood cells (RBCs) were injected intravenously into normal C3H(He) female mice and the rate of clearance and organ distribution of the isotope were observed over a 30 h period. It was found that trypanosomes and xenogeneic RBCs were cleared rapidly from the peripheral blood and accumulated primarily in the liver, spleen, lungs and kidneys. A difference was noted in accumulation of trypanosomes and RBCs in these mice.     

Schistosoma mansoni: Antischistosomal activity of the four optical isomers and the two racemates of mefloquine on schistosomula and adult worms in vitro and in vivo

Recent studies have shown that mefloquine (MQ) reveals interesting antischistosomal properties. We examined the antischistosomal activities of the erythro and threo isomers and racemates of MQ on newly transformed schistosomula (NTS) and adult Schistosoma mansoni in vitro and in mice harbouring adult S. mansoni. The in vitro effects in the presence and absence of haemin were monitored by means of microcalorimetry, scanning electron microscopy and phenotypic evaluation. Incubation of NTS with the erythro derivatives at concentrations of 3 μg/ml and above resulted in convulsions, granularity, decrease in heat flow, and death while NTS incubated with the threo derivatives were only affected at high concentrations (100 μg/ml). Extensive tegumental alterations, decrease in metabolic activity, viability, and death were observed when adult schistosomes had been exposed to 10 μg/ml of the erythro compounds. Moderate tegumental and viability changes but reduced heat production rates were observed with the threo derivatives at 10 μg/ml. In the presence of haemin, all MQ derivatives showed pronounced antischistosomal properties against adult S. mansoni in vitro. In vivo, MQ derivatives achieved statistically significant total and female worm burden reductions ranging between 65.4% and 100%. The highest total worm burden reductions of 93.4% and 90.2% were observed following treatment with the erythro and threo racemates, respectively. In conclusion, the optical isomers and racemates of MQ show only moderate stereoselectivity, in particular in vivo. Our results may enhance our understanding of the mechanism of action and therapeutic profile of MQ derivates on schistosomes.     

Biological control of brown rot (Moniliana laxa Ehr.) on apricot (Prunus armeniaca L. cv. Hacıhaliloğlu) by Bacillus, Burkholdria, and Pseudomonas application under in vitro and in vivo conditions

In 2002 and 2003, a study was conducted to determine the effect of bacterial strains, Burkholdria OSU 7, Bacillus OSU 142, and Pseudomonas BA 8, on biological control of brown rot disease (Monilinia laxa Ehr.) on apricot cv. Hacıhaliloğlu in Malatya province of Turkey. Apricot orchard at full blooming stage was inoculated with conidial suspension (1 × 10⁶ spores/ml) of M. laxa Ehr. After inoculation, two apricot trees for each application were treated with each of the three biological control agents (Burkholdria gladii OSU 7, Bacillus subtilis OSU 142, and Pseudomonas putida BA 8) by spraying (1 × 10⁹ cfu/ml) on inoculated branches. Disease incidence was evaluated for untreated (control 1) and four different treatment groups including commercial disease management (control 2, positive control: 3% Bourdox in fall, 50% Cupper at pink flower, 30 g/100 l Corus at first blooming, and 300 g/100 l Captan at last blooming stage) and treatments including each of the three bacterial strains (OSU 7, OSU 142, and BA 8). The results showed that disease incidence for negative control (control 1) was 9.94, which was significantly higher than disease incidence for commercial application (2.57%) or bacterial treatments (2.82–5.00%) in the first year. In 2003, the lowest disease incidence observed in OSU 7 treatment (6.80%), while disease incidence rate for positive control and negative control were 9.45% and 28.46%, respectively. This result may suggest that OSU 7 has potential to be used as biopesticide for effective management of brown rot disease on apricot.