竹材主要变色菌霉菌的生长特性研究

从我国云南、广州、北京、湖南和安徽等省市采集变色霉变竹材标本,分离纯化得到78株真菌菌株,鉴定为木霉(Trichoderma spp.)、毛霉(Rhizomucor spp.)、曲霉(Aspergillus spp.)、镰刀菌(Fusarium spp.)、链格孢菌(Alternaria spp.)、可可毛色二孢菌(Botryosphaeria rhodina)和稻球黑孢(Nigrospora oryzae)等。选取代表性的菌株进行了生物学特性的研究。营养因子对菌株生长的影响研究表明:碳素营养和氮素营养均影响菌丝的生长及色素形成;温度条件对菌株的生长影响较大,对于大多数菌株而言,28 ℃是最适生长温度,5 ℃生长减缓甚至停滞,但未死亡, 40 ℃以上菌株的生长受到抑制甚至死亡,但个别霉菌在50 ℃仍可生长,表明竹材霉菌对极端环境有一定的适应能力;竹材霉菌变色菌对酸碱度的适应范围较广,pH值在4 - 11下皆能正常生长,最适pH值在5 - 8间;光照对菌株生长的影响不大。     

A retrospective study of the clinical, histological, and immunohistochemical manifestations of 5 dogs originally diagnosed histologically as necrotizing scleritis

Purpose To describe the clinical, histological, and immunohistochemical manifestations of canine necrotizing scleritis. Methods A retrospective examination of the clinical records and samples of ocular tissues from five dogs with a histological diagnosis ‘necrotizing scleritis’ was completed. Archived, formalin‐fixed, paraffin‐embedded samples and two control globes were stained with hematoxylin and eosin, Gram, periodic acid–Schiff (PAS) and Masson trichrome stains, and they were immunohistochemically labeled for CD3, CD18, and CD20. Results Of the five cases reviewed, only two could be confirmed as idiopathic necrotizing scleritis. The other three cases were retrospectively diagnosed as unilateral focal, non‐necrotizing scleritis, one as episcleritis and the third was scleritis secondary to a proptosed globe based on our retrospective clinical, histological, and immunohistochemical evaluations. In these two cases, idiopathic necrotizing scleritis manifested as a bilateral, progressive, inflammatory disease of the sclera and cornea that induces significant uveitis. Light microscopic examination confirmed collagen degeneration and granulomatous inflammation. There was no evidence for an infectious etiology based on Gram’s and PAS stainings. Immunohistochemical labeling revealed a predominance of B cells in idiopathic, bilateral necrotizing scleritis. Tinctorial staining abnormalities with Masson’s trichrome stain were present in scleral collagen of the two cases with idiopathic necrotizing scleritis as well as a case of secondary traumatic scleritis. Conclusions Based on a limited number of cases, idiopathic canine necrotizing scleritis shares similar histopathological features with non‐necrotizing scleritis and episcleritis; however, necrotizing scleritis is B‐cell‐dominated and bilateral, and significant collagen alterations manifest with Masson’s trichrome stain.     

XPS and FTIR studies of fungus-stained Daemonorops margaritae

We explored the discoloration of rattan cane using X-ray photoelectron spectroscopy(XPS) and Fourier transform infrared spectroscopy(FTIR). XPS analysis showed that after the cane was stained by Lasiodiplodia theobromae, carbon and oxygen elements and the ratio of oxygen to carbon decreased. Considering atomic binding,C_1 and C_4 contents increased, while C_2 and C_3 contents decreased, and the ratio of O_2 to O_1 decreased sharply. The relative contents of lignin, cellulose and polysaccharides increased and new substances with low O_2/O_1 ratio occurred. FTIR analysis showed that the absorption peaks of O–H at 3346 cm^-1, aliphatic C–H at 2921, 2853 and1464 cm^-1, and C=O at 1723 cm^-1, were characteristic peaks of fungal melanin intensified, indicating that cane discoloration was primarily caused by fungal melanin. The absorption peaks characterizing cellulose and lignin like polysaccharides at 800 cm^-1, C–H at 1374 cm^-1, C–O at1058 and 1038 cm^-1, phenolic hydroxyl at 1245 cm^-1,aromatic ether bonds at 1270 cm^-1, carbon skeleton at1608 cm^-1 and benzene ring at 1500 cm^-1 were enhanced since the fungus mainly consumed the extractives in cane cell lumens and the main composition content increased relatively. Regardless of the discoloration caused by natural fungi or inoculated fungi, the discoloring feature and composition changes were identical except that the fungusinoculated cane had more melanin.     

干燥鸡胸肉宠物食品护色研究

为研究干燥鸡胸肉宠物食品在生产和贮藏过程中的颜色变化,减少因颜色变化引起的产品质量问题,采用三因素二次通用旋转组合设计,研究二丁基羟基甲苯(BHT)、柠檬酸和焦亚硫酸钠3种抗氧化剂对干燥鸡胸肉干贮藏过程中颜色变化影响规律。结果表明,BHT的护色效果最好,焦亚硫酸钠的护色效果次之,柠檬酸的护色效果最差。复配试验结果表明,0.02% BHT、0.10%柠檬酸、0.05%焦亚硫酸钠的组合配方护色效果最好,可有效改善干燥鸡胸肉宠物食品在生产和贮藏过程中颜色变化问题。     

大白菜游离小孢子培养胚胎发生中的加倍机制

 利用Leica体视显微镜, DAPI荧光染色观察比较大白菜小孢子正常发育为成熟花粉粒与游离小孢子培养胚胎发生细胞核的分裂方式, 探讨大白菜游离小孢子培养胚胎发生及其自然加倍的机理。观察结果显示以B途径为主要发育途径的大白菜小孢子, 胚胎发生的启动机制是热激诱导下单倍体小孢子体积膨大, 染色体发生自然加倍, 从而激发小孢子进入孢子体发育途径; 大白菜小孢子胚再生植株具有较高的自然加倍率, 这与小孢子培养热激诱导激发小孢子单核自然加倍为二倍体密切相关。     

A fast,low‐cost and efficient method for the diagnosis of sperm DNA fragmentation in several species

Sperm DNA fragmentation is a condition that interferes directly in the reproductive efficiency. Currently, there are several methods for assessing the sperm DNA integrity, such as Alkaline Comet, TUNEL and Sperm Chromatin Structure Assay. However, many of these techniques are laborious and require high‐precision equipment. Thus, the development of new techniques can optimize the evaluation of sperm DNA damage. Therefore, the aim of this study was to standardize the toluidine blue (TB) stain technique for the analysis of DNA fragmentation of dog, cat, bull, stallion and ram spermatozoa. For this purpose, we used six animals of each specie (n = 30), in reproductive age. Sperm was collected by different methods according to the particularities of each species, and such samples were divided into two aliquots: a sperm sample was kept at 5°C (considered as intact sperm DNA), and the remaining samples were submitted to the induction of DNA fragmentation by exposure to ultraviolet light for 4 hr. Samples were then mixed with the intact sample to obtain known and progressive proportions of sperm with fragmented DNA (0%, 25%, 50%, 75% and 100%). Semen smears were performed and subjected to staining with TB. Blue‐stained spermatozoa were considered to have DNA fragmentation. We observed high linear regression coefficients between the expected proportion of damaged DNA and the results of TB for dog, cat, ram, bull and stallion samples. In conclusion, TB stain was considered a fast and effective technique for the study of spermatozoa DNA in several species.     

Comparison of four staining methods for detection of mast cells in equine bronchoalveolar lavage fluid

Mast cells normally are present in equine bronchoalveolar lavage fluid (BALF), but usually represent <2% of all cells in healthy horses. An increased percentage of mast cells has been associated with airway hyperactivity and inflammatory airway diseases, but marked differences are reported between studies in normal and diseased horses. Because an abnormal mast cell count may be of clinical relevance, we compared the ability of a fast Romanowsky method to stain mast cell granules with that of 3 metachromatic stains: automated Romanowsky, May-Grünwald Giemsa, and toluidine blue stains. The BALF cells from 24 horses were studied. A differential cell count was performed blindly on 400 cells. The percentages of mast cells obtained were analyzed by means of repeated-measures analysis of variance and Fischer's PLSD test. The Bland and Altman method was used to assess agreement among stains. The mean percentage of mast cells in BALF was significantly lower with the fast Romanowsky than with the automated Romanowsky, May-Grünwald Giemsa, and toluidine blue stains. With the fast Romanowsky stain, the metachromatic granules of mast cells were not stained, and their identification was based on morphologic criteria. Toluidine blue staining allowed detection of the highest mean percentage of mast cells, but was inadequate for performing a differential cell count on other cell types. In conclusion, fast Romanosky stain may be inadequate for detection of mast cells in equine BALF, whereas automated Romanowsky, May-Grünwald Giemsa, and toluidine blue stains provide metachromatic staining of mast cell granules.     

<Emphasis Type="Italic">Platanus</Emphasis> × <Emphasis Type="Italic">acerifolia</Emphasis> genotypes surviving to inoculation with <Emphasis Type="Italic">Ceratocystis platani</Emphasis> (the agent of canker stain): first screening and molecular characterization

Canker stain, caused by the fungus Ceratocystis platani, is a destructive disease in Platanus spp. It has been recently proved that resistant accessions can be produced and grown in Europe. However, additional resistant genotypes are still needed in order to avoid the onset of virulent pathogen strains favoured by the selection pressures exerted by genetically homogeneous resistant plane tree plantings. In this study we present the results of two parallel experiments performed on 975 accessions of P. × acerifolia seedlings and P. × acerifolia clones derived by cutting propagation from mature trees grown in the urban environments. The selection process was based on inoculation with C. platani and yielded 13 accessions that showed different types of resistant reactions and survived in a stable manner thoughout the period of observation. Selected accessions were characterised by sequencing the rDNA-ITS region and by developing PCR procedures capable of detecting P. orientalis and P. occidentalis LEAFY homoeologues. These molecular analyses enabled us to confirm the identification of the species, its hybrid origin and to assess an evident genetic variability among the accessions, which therefore have to be considered as different genotypes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

微生物学实验教学中革兰氏染色三步法应用试验

通过实验室应用试验证明,革兰氏染色三步法虽操作简单、染色快、成功率高、效果好.但要严格控制相关环节,即革兰氏阳性菌菌龄16-20h,革兰氏阴性菌菌龄22-24h;取菌量要少于1/3环,涂菌要稀薄、分散均匀;在结晶紫和碘液染色时间各1 min条件下,第三步以0.4%碱性品红乙醇液处理时间60-90s,或以0.3%蕃红乙醇液处理时间90-120s,效果较佳.     

Ceratocystis platani is killing plane trees in Istanbul (Turkey)

Ceratocystis platani was detected at several locations in the European side of Istanbul, causing severe dieback and mortality, mainly on Platanus × acerifolia imported from Italy approximately 160 years ago, but also on Platanus orientalis. In the work reported here, the causal agent of the dieback and mortality was identified based on morphological characteristics in culture and internal transcribed spacer (ITS) sequencing, confirming the presence of C. platani in Turkey. All analysed C. platani isolates from Istanbul shared the same ITS sequence with European C. platani strains available in the NCBI, but differed from other species previously ascribed to the Ceratocystis fimbriata species complex. Pathogenicity of C. platani was proven by inoculation onto 25‐cm‐long and 4–9 mm diam. P. orientalis twigs and the causal agent reisolated from symptomatic tissues. In a survey of 976 Platanus in streets and parks of Istanbul, 26.5% of trees showed symptoms of C. platani infections, whilst 5.6% were dead. The proportion of symptomatic trees was higher where management interventions, such as topping or pruning and felling infected trees had been carried out.