立克次体分类研究的进展

由于分子生物学在立克次体分类研究中的应用,立克次体的分类发生了很大的变化,原属立克次体科,立克次体族的罗沙利马体属和柯克斯体属,均因１６ＳｒＲＮＡ序列分析表明与其它立克次体亲椽关系较远,而建议它们不属于立克次体科,前者近年来已改称巴通体属,立克次体属中的恙虫病立克次体亦因其表型和基因型特点而有另立一新属的建议,埃立克体属中亦增加了对人致病的新成员。     

恙虫病立克次体分子生物学研究进展

恙虫病立克次体（Rickettsiatsut－sugamushi,Rt）是一类以恙螨为传播媒介,专性细胞内奇生的微生物。恙虫病（ScrubTxpes）是一种自然疫源性疾病,主要流行于亚洲、太平洋一带。在我国,以往经病原学证实恙虫病只分布于长江以南和台湾省,而1986年以来山东及江苏相继发生了恙虫病暴发流行,90年代初期新疆、天津北部农村和山西侯马也发现了恙虫病流行。1991－1995年我所在东北三省从野鼠和恙虫中共分离出19株Rt,首次证实东北地区也存在恙虫病的自然疫源地。可见恙虫病仍是一值得注意的问题,要弄清恙虫病在我国的流行情况仍需采用先进…     

类立克次体侵染中华绒螯蟹神经组织的光镜和电镜观察

对患颤抖病的中华绒螯解（Eriocheir sinensis）神经和肌肉组织进行光镜和电镜观察,结果显示类立克次体广泛存在于胸神经节中的神经胶质细胞、结缔组织以及细胞间隙中。在神经细胞与步足肌肉细胞连接处,即运动终板部位有大量类立克次体侵染,并且侵染方式与在胸神经节中一样,均以聚集成团的形式存在。胸神经节是支配步足的神经丛,而颤抖病是以步足颤抖为病症的疾病。类立克次体大量侵染胸神经节和运动终板部位,表明该微生物与病蟹步足颤抖的病症有密切关系,进一步证明类立克次体是颤抖病的致病微生物。     

气相色谱-质谱法对斑点热群立克次体

本文报告应用气相色谱-质谱法分析了13株斑点热群立克欢体(7株中国分离株和6株国际标准株）泛影葡胺密度梯度离心纯化物的全细胞脂肪酸成分。结果表明,各被检测的立克次体株所含主要脂肪酸成分百分含量有区别,所得色谱图经多兀聚类法处埋的7株中国分离株与国际标准株中的西伯利亚立克次体相近,而与其它国际标准株则有明显区别。     

感染小鼠组织中Q热立克次体的分子病理学检测

腹腔注射Q热立克次体悬液感染BALB／c小鼠,发病后解剖,取主要组织脏器,应用免疫组化和原位杂交检测感染小鼠体内Q热立克次体的抗原分布和DNA在靶细胞中的表达,探讨Q热病变规律及致病机理。结果显示阳性信号多位于单核-巨噬细胞系统细胞胞浆内。结果提示免疫组化和原位杂交技术可以作为Q热特异性的诊断方法,并为致病机理的研究提供线索。     

立克次体遗传学研究进展

立克次体遗传学研究进展庄合安,范明远（北京地坛医院病毒研究室,北京１０００１１）１引言立克次体通常是指包括立克次体（Ｒｉｃｋｅｔｔ－ｓｉａ）、罗沙利马体（Ｒｏｃｈａｌｉｍａｅａ）和柯克斯体（Ｃｏｘｉｅｌｌａ）三个属的一大类细菌,除罗沙利马体外均为专性...     

应用PCR技术检测病人血液标本中斑点热群立克次体DNA

本文以聚合酶链反应（PCR）,采用二次扩增法直接检测蜱传斑点热病人血液标本中斑点热群立克次体DNA,结果从7份标本中检出阳性1份,进一步的限制性片段多态性分析证明和斑点热群黑龙江立克次体基因型相同。实验证明：黑龙江立克次体对人具有致病性,同时也证明PCR技术快速、简单、敏感,用于斑点热群立克次体的早期诊断是可行的,并可作出分型鉴定。     

黑龙江立克次体的血清学及分子生物学研究

本文应用血清学方法和分子生物学技术,从不同角度探讨与比较ＳＦＧ立克次体种间的差异,为黑龙江立克次体的分类鉴定提供依据。ｍｉｃｒｏ—ＩＦ、ＩＥ及ｍｉｃｒｏ－ＢＡＰＳ试验表明,黑龙江立克次体的血清反应模式和国际参考株及国内分离株不同,具有独特的抗原结构。进一步应用ＳＤＳ—ＰＡＧＥ和免疫印迹分析,该立克次体结构多肽的数量与分子量和其它立克次体有明显差别,并具有两种特有的主要抗原多肽（２１５ＫＤ与６６ＫＤ）,提示在抗原结构上的差异性。ＤＮＡ限制片段分析证明该立克次体的酶切图谱有明显的特征性,易与己知斑点热毒株相鉴别。研究结果表明,黑龙江立克次体可能是ＳＦＧ立克次体一新的血清型式种。对人的致病力需进一步研究。     

斑点热群新疆立克次体对宿主细胞感染过程的形态学研究

对新疆立克次体(精河株,下同)感染体外培养的人胚肾传代细胞(简写MERN)和体内鸡胚卵黄囊膜细胞的标本进行了电镜观察。发现立克次体以宿主细胞膜内翻形式进入宿主细胞,在胞浆和胞核内寄生,以二分裂方式增殖;并能察见多个立克次体的链状结构;胞浆内的菌体以核膜内翻方式进入核内,以密集成丛或散在方式生长;在感染后第5—8天的MERN中,立克次体以出芽方式释放,在第8天后通过宿主细胞解体方式释放。文中讨论了新疆立克次体感染宿主细胞过程中的有关机制。我们还发现在宿主细胞内立克次体的附近有直径为20—23nm的微管结构,其功能待深入研究。     

黑龙江立克次体与黑龙江蜱传斑点热研究概况

黑龙江立克次体是近年发现的斑点热群立克次体新种,由其引起的疾病为黑龙江蜱传斑点热。综述了黑龙江立克次体的发现、分离鉴定、病原学和分子生物学特征,介绍了黑龙江蜱传斑点热的流行病学、临床表现及治疗与预防。     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

Prostaglandin and thromboxane production by human and guinea-pig macrophages and leucocytes

The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE₂, PGD₂, PGF_2α, TXB₂ and 6-keto-PGF_1α. In all types studied PGE₂ and TXB₂ were the major products formed. The identification of PGE₂ and TXB₂ was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.     

Chemokines and cytokines: axis and allies in asthma and allergy

Allergic asthma can be precipitated by many factors. For the atopic person, fungus, pollen, dust mites, cockroach antigens, and diesel exhaust are all agents that may trigger an allergic attack. Cytokines and chemokines are integral mediators of fungal asthma. From the earliest time points, they recruit and activate the cells required for the clearance of fungus as well as being critical factors involved in the immunopathology of this disease. In the final analysis, it is clear that these mediators can act to the benefit or the detriment of the host.     

Oxidation and nitration of ribonuclease and lysozyme by peroxynitrite and myeloperoxidase

In spite of the many studies on protein modifications by reactive species, knowledge about the products resulting from the oxidation of protein-aromatic residues, including protein-derived radicals and their stable products, remains limited. Here, we compared the oxidative modifications promoted by peroxynitrite and myeloperoxidase/hydrogen peroxide/nitrite in two model proteins, ribonuclease (6Tyr) and lysozyme (3Tyr/6Trp). The formation of protein-derived radicals and products was higher at pH 5.4 and 7.4 for myeloperoxidase and peroxynitrite, respectively. The main product was 3-nitro-Tyr for both proteins and oxidants. Lysozyme rendered similar yields of nitro-Trp, particularly when oxidized by peroxynitrite. Hydroxylated and dimerized products of Trp and Tyr were also produced, but in lower yields. Localization of the main modified residues indicates that peroxynitrite decomposes to radicals within the proteins behaving less specifically than myeloperoxidase. Nitrogen dioxide is emphasized as an important protein modifier.