自然干燥对冬虫夏草寄主蝠蛾卵孵化的影响

研究在室内自然空气湿度下放置的时间长短对冬虫夏草(Cordyceps)寄主昆虫贡嘎蝠蛾Hepialus gonggaensis Fu et Huang卵孵化率的影响。卵早期的研究结果为:第1批、第2批和第3批卵于室内自然空气湿度下保存的时间达26,11和16h后再保湿都可以正常孵化并且孵化率与对照无显著性差异,所孵化幼虫在饲养初期的成活率分别达62.0%,41.4%和43.4%,与对照无显著性差异。卵中期干燥放置36h的孵化率为66.7%,所孵化幼虫在饲养初期的成活率为50.0%,孵化率和成活率都与对照无显著性差异。卵晚期干燥放置24h的孵化率为70.0%,所孵化幼虫在饲养初期的成活率为49.0%,孵化率和成活率都与对照无显著性差异。以上结果表明,经历一定时间的干燥不会对卵的正常孵化有影响。     

Long-Term Storage of Bacteriophages of Lactic Streptococci

Four phage strains representing phages of Streptococcus lactis, S. cremoris, and S. diacetilactis were selected for the observation of the effect of cold storage on their viability. Phages were stored at 4 C and at -18 C, or were frozen at approximately -70 C and stored at -18 C. They were found to display a high degree of stability with these storage methods. The same phage strains showed good stability to storage at room temperature for 3 weeks after thawing and also to alternate freezing and thawing eight times. Three series consisting of from 23 to 31 lactic streptococcal phage preparations were observed over periods extending up to 6 years, and with only a few exceptions were found to store satisfactorily at -18 C after quick freezing. Although the same phage preparations stored at 4 C were generally somewhat less stable, many were stable when stored by both methods.     

小峰熊蜂蜂王蛹期发育蛋白质组分析

为了探明小峰熊蜂Bombus hypocrita蜂王蛹期发育蛋白质表达调控方面的特点,揭示其发育的分子机理。采用双向电泳法对小峰熊蜂蜂王蛹期发育进行蛋白质组研究,结果在小峰熊蜂蜂王蛹期的白眼期(A期)、褐眼期(B期)和黑眼期(C期)分别检测到81、80和75个蛋白点,特有蛋白质分别为8个、7个和2个,共有蛋白质为61个,A期到B期有4个蛋白质显著上调,5个显著下调,B期到C期有7个蛋白质显著上调,1个显著下调,A期到C期有10个蛋白质显著上调,有4个显著下调。此外,3个蛋白质是在A、B期表达C期关闭,6个蛋白质A、C期表达,B期关闭,5个蛋白质A期关闭,而B、C期表达。初步表明小峰熊蜂蜂王从蛹期发育到成蜂过程中,不仅需要一些保守蛋白质来调控,而且还需要一些特异蛋白质。     

三个品系小型猪正常心电图的比较

目的建立清醒状态记录小型猪心电图的方法,并对3个品系小型猪6个导联心电图进行分析比较。方法选用4月龄广西巴马猪7头、5月龄五指山小型猪6头、中国农大小型猪10头,清醒状态下吊床保定,测定Ⅰ、Ⅱ、Ⅲ、aVR、aVL和aVF6个导联的心电图。结果3个品系小型猪心电图的波形与人相似,心率较快,在3个品系之间差别不明显,存在偶发性窦性心率不齐。广西巴马猪、五指山小型猪和中国农大小型猪的P-R间期分别介于0．08—0．10s、0．08—0．11s和0．08—0．11s;QRS波群分别介于0．04—0．06s,0．04—0．07s和0．04～0．05s。3个品系小型猪均有清晰的S-T段,偏移小于1mm。结论本研究获得了3个品系小型猪清醒状态时的心电图基本数据,经比较,3个品系之间无明显差异。     

恒河猴麻疹病的诊断与治疗

目的探索恒河猴麻疹病的诊断、治疗及防制方法。方法隔离病猴,采集猴血清,环境消毒,对病死猴进行病理学观察、抗体ELISA和病毒免疫组织化学检测,以及治疗。结果病猴被确诊为患猴麻疹,隔离发病猴3只,其中死亡1只,康复2只,未出现麻疹病的进一步扩大流行。采用头孢曲松钠、地塞米松、利巴韦林等治疗取得了显著治疗效果。结论预防是控制麻疹病的关键,运输及环境改变是致病的诱因,快速诊断、科学用药和综合防治是减少损失的关键。     

两种血吸虫病DNA疫苗的候选抗原基因研究

目的：以日本血吸虫基因SjFABP和SjGST原核表达产物检测二价DNA疫苗pVIVO2-SjFABP-SjGST在体内诱发的特异性抗体。方法：克隆日本血吸虫抗原基因SjFABP和sjGST,构建重组原核表达载体pET30a-SjFABP、pET30a-SjGST及真核表达载体pVIVO2-SjFABP-SjGST;将pET30a-SjFABP和pET30a-sjGST进行原核表达,并将表达产物用镍亲和柱分离纯化;采用Western印迹对日本血吸虫DNA疫苗pVIVO2-SjFABP-SjGST免疫4周后的BALB／c小鼠血清进行特异性抗体检测。结果：克隆了日本血吸虫抗原基因SjFABP（399bp）和町GST（657bp）,并构建了pET30a-SjFABP、pET30a-SjGST及pVIVO2-SjFABP-SjGST重组质粒;经Western印迹检测,pET30a-SjFABP及pET30a-SjGST原核表达的抗原蛋白均能够与经日本血吸虫二价DNA疫苗pVIVO2-SjFABP-SjGST免疫的小鼠的血清产生特异性免疫反应。结论：日本血吸虫町尉即和町GST基因的原核表达系统成功建立;原核表达的抗原蛋白具有免疫原性;以原核表达产物可检测日本血吸虫DNA疫苗pVIVO2-SiFABP-SiGST在体内诱发的特异性抗体。     

Ultrastructure of the encapsulation of Plasmodium cynomolgi (B strain) on the midgut of a refractory strain of Anopheles gambiae

Using transmission electron microscopy, we investigated the encapsulation of the simian malaria parasite, Plasmodium cynomolgi, in a refractory strain of the mosquito, Anopheles gambiae. After the ookinete penetrates the mosquito midgut epithelium and lodges between the basal membrane and the basal lamina, an electron-dense, melanin-like substance begins to coalesce around the parasite. Completely encapsulated parasites were found as early as 16 hr after the blood meal. Granules of the melanin-like substance often appeared to condense onto the parasite from the fluid in the extracellular spaces of the basal membrane labyrinth. Melanin granules also appeared to condense from the hemolymph onto the basal lamina underlying the parasite. In addition, groups of tubules, vesicles, and membranous whorls often were found in midgut cells that were located next to or were enclosing parasites. These structures were unusually electron-dense, and may have been associated with melanization. Hemocytes rarely were observed near completed capsules and neither hemocytes nor their remnants were components of the capsules. During later stages of encapsulation, parasites appeared abnormal and often were infiltrated with melanin. Although late-stage capsules were usually located basally, completed capsules enclosed by membranes were occasionally observed near the apical border of the midgut. Other capsules associated with cellular debris, were found in the lumen of the midgut from 1 to 6 days after the blood meal.     

Light microscopic study of blood vessels of the nasal cavity of the pig

4 adult pigs were used for light microscopic studies to depict the relationship between nasal blood vessels and the surface epithelium, and to describe the histomorphology of these vessels. After giving an electric shock, animals were bled to death. Tissues were collected from three regions in the nasal cavity after splitting heads sagitally. Different types of vessels were described and a new classification was suggested. Arteries were muscular in type with, as well as without, internal elastic laminae. Thick-walled veins (characterized by smooth muscle cells in the tunica media) were present throughout the nasal cavity, while thin-walled veins or cavernous spaces were discernible only in the caudal one third of the nasal cavity. Further, arteriovenous anastomoses, epithelioid arterioles, and free smooth muscle cells in the propria submucosa were observed throughout the nasal cavity.     

Pili of Pasteurella multocida of porcine origin

Abstract Using electron microscopy, pili with at least two distinct morphologies were observed on strains of Pasteurella multocida isolated from pigs with atrophic rhinitis. Rigid pili were found on 60–80% of all cells observed. These pili had a strong tendency to lie flat along the side of the outer cell membrane of P. multocida and as a result frequently were difficult to see. After growth in vitro, piliated P. multocida cells produced few pili (approx. 3–5 per cell). Heavily piliated cells were occasionally observed. The second type of pili were curly and also were difficult to visualize. Cells from cultures containing piliated cells failed to attach to red blood cells and to immobilized mucus.     

Characterization of Aeromonas salmonicida subsp. salmonicida: a comparative study of strains of different geographic origin

A total of 130 strains of the fish pathogen Aeromonas salmonicida isolated in Denmark, Norway, Scotland, Canada and the USA were examined. The strains originated from farmed salmonid fish. The biochemical, physiological and serological characteristics, antibiotic resistance patterns and cell surface-related properties were compared. Aeromonas salmonicida was found to be remarkably consistent in general cultural and biochemical characteristics. It is noteworthy that the strains were positive in the fermentation of L-arabinose and were negative in the fermentation of D-arabinose. All the strains were highly proteolytic. It was observed, however, that 5% of the strains did not digest calf and trout serum and the production of haemolysin and degradation of casein by the same strains were delayed compared with the other strains. Common to all of the rough strains were auto-aggregation and ability to bind the dyes Coomassie brilliant blue and Congo red and the majority of these strains were highly hydrophobic. The strains were tested for their susceptibility to 22 antibacterial agents. Antibiotic resistance profiles of Aer. salmonicida indicated that resistance to the quinolones and oxytetracycline was increasing and that multi-resistant strains were found in several countries. The variation found in antibiograms could have potential as epidemiological markers in certain geographic areas.     

First observations of the burrows of Anguilla japonica

The burrow morphology of the Japanese eel Anguilla japonica was studied using in situ resin‐casting in a mud bottomed tidal drainage channel adjacent to the Fukui River in Tokushima, Japan. Two eels (62·5 and 56·3 cm total length) were initially fished from the burrows to verify that they were being used by A. japonica . Casts were made of 10 burrows that were found to have from one to three openings and main tunnels that were parallel to the axis of water flow in the channel. The maximum depths of the tunnels in the mud were 17·8–30·0 cm. The diameters of main tunnels ranged from 1·2 to 7·9 cm, were almost always wider than the bodies of the Japanese eels examined, and were more variable in the horizontal axis than in the vertical axis. There were no other animals capable of constructing a long and thin burrow in this channel, so these observations indicate that anguillids are able to construct their own burrows in soft mud sediments that may be used for extended periods of time.     

Origin of intestinal disaccharidases of Ascaris suum

Disaccharidases from the gut of Ascaris suum were investigated to determine whether they were synthesized by the worm or whether they were host enzymes adsorbed to the worms' intestinal cells. Alpha-d-glucoside glucohydrolase (maltase) (EC 3.2.1.20), Beta-d-fructofuranoside fructohydrolase (invertase) (EC 3.2.1.26) and 1-glucohydrolase (trehalase) (EC 3.2.1.28) from Ascaris were studied in both a membrane (brush border)-bound and solubilized form with regard to temperature stability and pH optima. Data collected were compared to similar data on hog intestinal enzymes. Worm maltase and trehalase were relatively heat labile, whereas the hog enzymes were more stable to heat inactivation. Worm invertase was heat stable in comparison to the hog enzyme. The pH optima for Ascaris maltase and invertase were different from those of hog disaccharidases, whereas the pH optimum for trehalase from both parasite and host were similar. Tissue homogenates of second-stage larvae contained measurable maltase, but not sucrase, or trehalase activity. Results suggested that Ascaris intestinal disaccharidases represent three distinct enzymes of parasite rather than host origin.     

百合属5种植物的比较转录组分析

百合属植物是多年生的宿根草本植物,具有重要的观赏价值,有的种可食用也可药用。本研究对百合属4种植物(细叶百合、川百合、卷丹和百合)花的转录组进行测序,并结合前期的野百合的转录组数据进行比较转录组分析,鉴别花发育相关基因。并筛选出5种植物的直系同源基因,进而检测正选择基因,分析它们对环境的适应性。通过组装分别在细叶百合、川百合、卷丹以及百合花中获得了44565、51413、41638和44716个unigene。为了了解unigene功能信息,将其在公共数据库中进行比对和注释,发现了13个花发育相关基因。另外,在5个物种间共获得8247对直系同源基因,并计算其Ka、Ks及Ka/Ks值。在5个物种中有33对直系同源基因受到了强烈的正选择作用,随后对其进行GO、KEGG功能富集分析及基因功能注释,发现这些基因主要是与抗性以及生物合成相关的基因。     

Organization of song of rose-breasted grosbeaks

Rose-breasted grosbeaks (Pheucticus ludovicianus) in Quebec had repertoires of fifteen to twenty-three syllables per bird, some of which were similar among neighbours. These were presented in songs with modes of nine to eleven syllables per song. Consecutive songs often began with the same syllables, even as many as three or four in succession, but overall sequences were usually different. The sequences were found to fit first and second order Markov models. Immediate repetitions of syllables within songs occurred uncommonly and were peculiar to particular syllables. The duration of intervals usually related directly to the immediately preceding syllables and song types. Where two syllables frequently followed another, the time intervals at the switches were usually significantly different between the two although the differences did not relate to the probabilities of the switches. There was a tendency to alternate long and short syllables. The applications of these findings to models of neural control are discussed.     

同时产多种基因型ESBLs肺炎克雷伯菌的分析

目的分析汕头大学医学院第一附属医院临床分离的肺炎克雷伯菌同时产多种基因型ESBLs的情况。方法采用PCR扩增对产ESBLs的肺炎克雷伯菌初步分型,然后PCR扩增阳性产物克隆测序分析,脉冲场凝胶电泳（PFGE）分型;用浓度梯度法检测10种抗菌药物对同时产多种基因型ESBLs的肺炎克雷伯菌的最低抑菌浓度（MIC）。结果83株产ESBLs的肺炎克雷伯菌中,发现9株同时产TEM、SHV和CTX-M型,测序结果为CTX-M-3、TEM-1及多种SHV型（SHV12及SHV28）。将这9株细菌作PFGE分析,结果共被分成7个型。药敏结果表明,9株菌除对亚胺培南敏感外,对氨曲南、头孢曲松、头孢噻肟、头孢他啶、丁胺卡那和四环素均高度耐药,对哌拉西林／三唑巴坦、头孢吡肟、环丙沙星极少菌株敏感。结论发现CTX—M-3超广谱-及多种SHV型超广谱-和TEM-1广谱β-内酰胺酶基因同时存在该院临床分离的肺炎克雷伯菌中,耐药十分严重,应引起重视。     

Vitrification of human islets of Langerhans

Cryopreservation of human islets of Langerhans by vitrification was studied. Isolated islets were divided into four groups: (1) control islets which were cultured for 6 days, (2) islets which were vitrified after 2 days of culture, (3) control islets which were cultured for 10-13 days, and (4) islets which were vitrified after 6-9 days of culture. After warming, islets from groups 2 and 4 were cultured for 4 days. The thus treated islets were investigated with respect to insulin secretion in the presence of 2.5 or 25 mM glucose, capacity to survive during postwarming culture, and morphology. The insulin secretion in islets from all groups could be stimulated by an increase of the concentration of glucose from 2.5 to 25 mM. No significant differences were observed between the insulin secretions of the vitrified and control islets or between the islets vitrified after 2 and 6-9 days of culture. It is concluded that human islets of Langerhans cryopreserved by vitrification are functional in vitro.     

Phylogenetics of the Monogenea--evidence from a medley of molecules

Nuclear ribosomal DNA sequences of Monogenea from both complete small and partial large (D1-D2) subunits were determined and added to previously published sequences in order to best estimate the molecular phylogeny of the group. A total of 35 ssrDNA, 100 D1 lsrDNA and 51 D2 lsrDNA monogenean sequences were used, representing a total of 27 families. From these sequences different data sets were assembled and analysed to make the best use of all available molecular phylogenetic information from the taxa. Maximum parsimony and minimum evolution trees for each data partition were rooted against published sequences from the Cestoda, forcing the Monogenea to appear monophyletic. There was broad agreement between tree topologies estimated by both methods and between genes. Well-supported nodes were restricted to deeply diverging major groupings and more derived taxa with the lsrDNA data but were at most nodes with ssrDNA. The Polyonchoinea showed the greatest resolution with a general pattern of ((Monocotylidae(Capsalidae(Udonellidae+Gyrodactylidea)))((Anoplodiscidae+Sundanonchidae)(Pseudomurraytrematidae+Dactylogyridae))). The Heteronchoinea readily split into the Polystomatoinea+Oligonchoinea, and Chimaericolidae and Hexabothriidae were successively the most basal of oligonchoinean taxa. Relationships within the Mazocraeidea, comprising 27 families of which 15 were sampled here, were largely unresolved and appear to reflect a rapid radiation of this group that is reflected in very short internal branches for ssrDNA and D1 lsrDNA, and highly divergent D2 lsrDNA. A reduced morphological matrix, employing only those families represented by molecules, contrasted sharply with respect to polyonchoinean interrelationships. Deep branches of the Heteronchoinea were similar for both classes of data but also showed that the interrelationships of the mazocraeidean families are labile and susceptible to sampling.     

Comparison of Effects of Sublethal Microwave Radiation and Conventional Heating on the Metabolic Activity of Staphylococcus aureus

This study was conducted in an attempt to characterize some of the effects of sublethal microwave radiation on cells of Staphylococcus aureus. Cultures were exposed to microwave radiation for 10, 20, 30, and 40 s. The effects of a conventional heat treatment were also compared by placing flasks containing cultures in a boiling water bath for the amount of time required to reach temperatures equivalent to those found in cultures exposed to microwave radiation. Control, microwave-treated, and conventionally heat-treated cultures were centrifuged, pellets were resuspended in distilled water, and the resulting suspensions were passed through a French pressure cell. Cell lysates and walls were then isolated and assayed for enzymatic activity. Thermonuclease production was also determined at various levels of exposure of cells to microwave radiation. Activities of malate and α-ketoglutarate dehydrogenases, cytochrome oxidase, and cytoplasmic adenosine triphosphatase were higher in microwave-treated cells than in control cells. Membrane adenosine triphosphatase, alkaline phosphatase, and lactate dehydrogenase activities were unaffected when cells were exposed to microwave radiation. The activity of glucose-6-phosphate dehydrogenase was decreased by exposure of cells to microwave radiation. In conventionally heated cells, activities of glucose-6-phosphate and malate dehydrogenases and cytoplasmic adenosine triphosphatase increased activities of α-ketoglutarate and lactate dehydrogenases decreased, and alkaline phosphatase activity remained unaffected. Increased levels of thermonuclease activity were observed when cells were exposed to microwave radiation for 10 or 20 s. Data indicate that microwave radiation affects S. aureus in a manner which cannot be explained solely by thermal effects.     

Lack of risk of transmission of caprine arthritis-encephalitis virus (CAEV) after an appropriate embryo transfer procedure

The aim of this study was to demonstrate that embryo transfer can be used to produce CAEV-free kids from CAEV-infected biological mothers when appropriate procedure is implemented. Twenty-eight goats that had tested positive for CAEV using PCR on vaginal secretions were used as embryo donors. Embryos with intact-ZP were selected and washed 10 times; they were then frozen and used for transfer into CAEV-free recipient goats. Nineteen of the 49 recipient goats gave birth, producing a total of 23 kids. Three blood samples were taken from each recipient goat, 10 days before, during, and 10 days after parturition; these were tested for CAEV antibodies using ELISA and for CAEV proviral DNA using PCR. The mothers were then euthanized. Tissue samples were taken from the lungs, udder, and retromammary and prescapular lymph nodes. The kids were separated from their mothers at birth. Seven of them died. At 4 months of age, 16 kids were subjected to drug-induced immunosuppression. Blood samples were taken every month from birth to 4 months of age; samples were then taken on days 15, 21, and 28 after the start of the immunosuppressive treatment. The kids were then euthanized and tissue samples taken from the carpal synovial membrane, lung tissue, prescapular lymph nodes, inguinal and retromammary lymph nodes, and uterus. All samples from the 19 recipient goats and 23 kids were found to be negative for CAEV antibodies and/or CAEV proviral DNA. Under acute conditions for infection this study clearly demonstrates that embryo transfer can be safely used to produce CAEV-free neonates from infected CAEV donors.     

The possible role of two species of Orthoptera in the dissemination of a plant pathogenic fungus

The ability of the locusts, Locusta migratoria and Schistocerca gregaria, to disseminate Colletotrichum graminicola, the fungal pathogen of maize anthracnose, were studied. The insects were fed with the diseased plants and spores were recovered in viable condition from the faeces. The spores recovered were able to grow on artificial media and were still infectious to the host plant.