Comparative analysis of oxygen transfer rate distribution in stirred bioreactor for simulated and real fermentation broths

Study of the distribution of the oxygen mass transfer coefficient, k _l a, for a stirred bioreactor and simulated (pseudoplastic solutions of carboxymethylcellulose sodium salt) bacterial (P. shermanii), yeast (S. cerevisiae), and fungal (P. chrysogenum free mycelia) broths indicated significant variation of transfer rate with bioreactor height. The magnitude of the influence of the considered factors differed from one region to another. As a consequence of cell adsorption to bubble surface, the results indicated the impossibility of achieving a uniform oxygen transfer rate throughout the whole bulk of the microbial broth, even when respecting the conditions for uniform mixing. Owing to the different affinity of biomass for bubble surface, the positive influence of power input on k _l a is more important for fungal broths, while increasing aeration is favorable only for simulated, bacterial and yeast broths. The influence of the considered factors on k _l a were included in mathematical correlations established based on experimental data. For all considered positions, the proposed equations for real broths have the general expression k_l a = aC_X^b ( \fracP_a V )^g v_S^d , k_{\rm l} a = \alpha C_{\rm X}^{\beta } \left( {{\frac{{P_{\rm a} }}{V}}} \right)^{\gamma } v_{\rm S}^{\delta } , exhibiting good agreement with experimental results (with maximum deviations of ±10.7% for simulated broths, ±8.4% for P. shermanii, ±9.3% for S. cerevisiae, and ±6.6% for P. chrysogenum).     

On the phylogeny of Mustelidae subfamilies: analysis of seventeen nuclear non-coding loci and mitochondrial complete genomes

Background  

Mustelidae, as the largest and most-diverse family of order Carnivora, comprises eight subfamilies. Phylogenetic relationships among these Mustelidae subfamilies remain argumentative subjects in recent years. One of the main reasons is that the mustelids represent a typical example of rapid evolutionary radiation and recent speciation event. Prior investigation has been concentrated on the application of different mitochondrial (mt) sequence and nuclear protein-coding data, herein we employ 17 nuclear non-coding loci (>15 kb), in conjunction with mt complete genome data (>16 kb), to clarify these enigmatic problems.     

Maternal inheritance of plastids and mitochondria in Cycas L. (Cycadaceae)

Cycas is often considered a living fossil, thereby providing a unique model for revealing the evolution of spermatophytes. To date, the genetic inheritance of these archaic plants is not fully understood. The present study seeks to document the process of organelle inheritance in an interspecific cross of Cycas species. Extranuclear organelle DNA from chloroplasts and mitochondria was analyzed using both polymerase chain reaction-restriction fragment length polymorphism analysis and microscopy. Here, we show that the chloroplasts and mitochondria in the progeny of interspecific crosses between Cycas taitungensis and Cycas ferruginea were exclusively inherited from the female parent. Epifluorescence microscopic analyses of the pollen cells from Cycas elongata indicated that there was a significant degradation of organelle DNA in male reproductive cells following maturation; the DNA fluorescent signals were only seen after pollen mitosis two, but not detectable at mature stage. Lack of organelle DNA fluorescent signal in prothallial cells was confirmed by the absence of plastids and mitochondria in electronic microscopic images. In conclusion, these data suggest that the maternal plastid and mitochondrial inheritance in Cycas, native to the old world, are the same as seen in seed plants.     

GRPR在宫颈疾病中的表达及临床意义

目的：研究胃泌素释放肽受体（GRPR）在正常宫颈组织、宫颈上皮内瘤样病变（CIN）、宫颈癌中的表达,探讨GRPR在促癌发生和癌生长等方面的生物学功能。方法：采用免疫组化SP法检测GRPR在28例宫颈癌、51例宫颈上皮内瘤变和15例正常宫颈组织中的表达情况,其中以正常宫颈组织作为对照。结果：在正常宫颈和宫颈癌组织中,GRPR阳性表达率分别为20%和92.9%。GRPR在CINⅠ、CINⅡ、CINⅢ中阳性表达呈上升趋势,差别无统计学意义。宫颈癌组的不同临床分期、有无淋巴结转移组间比较,GRPR的阳性表达率均有显著性差异,并随病情严重程度的增加,阳性率增高,其表达强度呈显著正相关。结论：GRPR的过度表达与宫颈癌的发生、发展有关,是宫颈癌发生的早期事件,其检测可作为评估宫颈癌恶性程度、判断预后及指导治疗的重要参考指标。     

NaCl胁迫对甘草生长及抗氧化酶活性的影响

目的：通过分析不同浓度NaCl胁迫下甘草生长和抗氧化酶活性的变化探讨甘草对盐分胁迫的适应性机理;方法：采用不同浓度的NaCl溶液（配成Hoagland液）处理盆栽一年生甘草,分别于35d、70d和105d取样,测定甘草株高、地上部分鲜、干重、根鲜、干重及甘草叶片SOD、POD、CAT活性,分析各生长指标与抗氧化酶活性的相关性;结果：NaCl胁迫70d和105d,0．6％和0．9％处理组的株高、地上部分鲜、干重及根鲜、干重均显著低于CK,SOD、POD及CAT活性均显著高于CK,经相关性分析得知,SOD、POD及CAT活性与各生长指标均负相关,其中POD活性与各生长指标极显著负相关;结论：甘草对NaCl胁迫的响应有胁迫时间和浓度的依赖性,在遭遇胁迫时,通过改变自身的生长和提高抗氧化酶活性,来提高机体的抗盐能力。     

磁敏感加权成像在帕金森病中的应用研究

目的：探索帕金森病（PD）的磁敏感加权成像（SWI）的表现。方法：34例帕金森病患者作为病例组和30例正常人作为对照组。采用GEL5T磁共振成像系统,行常规的快速自旋回波T1、T2加权像后,加扫三维磁敏感加权成像覆盖基底节区及中脑。使用SWI后处理软件在校正相位图上两次测量双侧尾状核头、苍白球、壳核、黑质、红核的相位值,最终的相位值取两次测量的平均值。结果：病例组患者黑质、壳核的相位值较对照组明显降低,差异具有统计学意义（P〈0．05）,PD患者黑质及壳核铁沉积增加。病例组壳核的相位值与PD病程之间存在负相关。对照组中尾状核头、壳核、黑质相位值左侧低于右侧。结论：SWI是显示PD患者脑内缺沉积的有效音白枪杏方法．     

应用两种方法诱导SH-SY5Y细胞分化的研究

目的：观察全反式维甲酸（ATRA）处理和ATRA与十四烷酰佛波醇乙酸酯（TPA）序贯处理（ATRA/TPA）对人类神经母细胞瘤细胞系SH-SY5Y细胞增殖抑制和形态分化的影响。方法：应用10μM ATRA处理6天和10μM ATRA处理3天继以80 nMTPA处理3天这两种方法使SH-SY5Y细胞分化;用倒置光学显微镜动态观察SH-SY5Y细胞形态学变化;并用MTT比色法比较两种分化方法对SH-SY5Y细胞的体外抗增殖作用。结果：ATRA处理和ATRA与TPA序贯处理对SH-SY5Y细胞都有抗增值和诱导细胞分化作用,细胞形态发生明显的变化,分化成神经元表型,前者主要表现为两端带有长突起的纺锤体样细胞形态,而后者主要是由细胞体延伸出多个突起的多边形的细胞。ATRA分化6天的细胞的存活率下降为78.7%±2.0%。当去除ATRA后,继续培养1天的细胞存活率上升为89%±0.2%,而继续培养2天的细胞存活率为86.3%±1.4%;ATRA与TPA序贯分化6天细胞存活率下降为75.9±0.4%。当去除TPA后,继续培养一天的细胞存活率为75.5±0.7%,继续培养2天的细胞存活率为74.9±1.0%。结论：维甲酸（ATRA）处理和ATRA与十四烷酰佛波醇乙酸酯（TPA）序贯处理（ATRA/TPA）均能明显诱导SH-SY5Y细胞分化。这两种分化细胞为神经科学的研究提供了优良的体外培养模型细胞,尤其是ATRA与TPA序贯处理能获得分化完全而稳定的神经元样细胞。     

瑞舒伐他汀对载脂蛋白E基因敲除小鼠动脉粥样硬化中调节性T细胞的影响

目的：探讨瑞舒伐他汀对载脂蛋白E基因敲除（ApoEKO）小鼠动脉粥样硬化中调节性T细胞的影响。方法：首先将30只ApoEKO小鼠建立动脉粥样硬化模型,随机分为高胆固醇饮食组（对照组）、瑞舒伐他汀低剂量组和瑞舒伐他汀高剂量组,各组分别给予蒸馏水或瑞舒伐他汀进行干预8周;将主动脉根部行冰冻切片油红染色,评估粥样硬化斑块面积大小;免疫组织化学法检测主动脉根部粥样硬化斑块处调节性T细胞（Treg）的表达。结果：各组小鼠均有动脉粥样硬化斑块形成,采用瑞舒伐他汀治疗的小鼠动脉粥样硬化斑块的面积明显小于未经治疗的小鼠（P〈0.01）,同时瑞舒伐他汀能明显增加粥样硬化病变处调节性T细胞的表达,且呈现剂效关系。结论：本实验观察到瑞舒伐他汀不仅能减小ApoEKO小鼠的主动脉粥样硬化斑块,且能使调节性T细胞的表达增多,推测瑞舒伐他汀可以通过促进调节性T细胞的生成而起到抑制动脉粥样硬化的作用。     

Glycoengineered Pichia produced anti-HER2 is comparable to trastuzumab in preclinical study

Mammalian cell culture systems are used predominantly for the production of therapeutic monoclonal antibody (mAb) products. A number of alternative platforms, such as Pichia engineered with a humanized N-linked glycosylation pathway, have recently been developed for the production of mAbs. The glycosylation profiles of mAbs produced in glycoengineered Pichia are similar to those of mAbs produced in mammalian systems. This report presents for the first time the comprehensive characterization of an anti-human epidermal growth factor receptor 2 (HER2) mAb produced in glycoengineered Pichia, and a study comparing the anti-HER2 from Pichia, which had an amino acid sequence identical to trastuzumab, with trastuzumab. The comparative study covered a full spectrum of preclinical evaluation, including bioanalytical characterization, in vitro biological functions, in vivo anti-tumor efficacy and pharmacokinetics in both mice and non-human primates. Cell signaling and proliferation assays showed that anti-HER2 from Pichia had antagonist activities comparable to trastuzumab. However, Pichia-produced material showed a 5-fold increase in binding affinity to FcγIIIA and significantly enhanced antibody dependent cell-mediated cytotoxicity (ADCC) activity, presumably due to the lack of fucose on N-glycans. In a breast cancer xenograft mouse model, anti-HER2 was comparable to trastuzumab in tumor growth inhibition. Furthermore, comparable pharmacokinetic profiles were observed for anti-HER2 and trastuzumab in both mice and cynomolgus monkeys. We conclude that glycoengineered Pichia provides an alternative production platform for therapeutic mAbs and may be of particular interest for production of antibodies for which ADCC is part of the clinical mechanism of action.Key words: glycoengineered Pichia, anti-HER2, trastuzumab, xenograft, PK, ADCC     

Identification of Mycobacterium tuberculosis-specific Th1, Th17 and Th22 cells using the expression of CD40L in tuberculous pleurisy

Important advances have been made in the immunodiagnosis of tuberculosis (TB) based on the detection of Mycobacterium tuberculosis (MTB)-specific T cells. However, the sensitivity and specificity of the immunological approach are relatively low because there are no specific markers for antigen-specific Th cells, and some of the Th cells that do not produce cytokines can be overlooked using this approach. In this study, we found that MTB-specific peptides of ESAT-6/CFP-10 can stimulate the expression of CD40L specifically in CD4(+) T cells but not other cells from pleural fluid cells (PFCs) in patients with tuberculous pleurisy (TBP). CD4(+)CD40L(+) but not CD4(+)CD40L(-) T cells express IFN-γ, IL-2, TNF-α, IL-17 or IL-22 after stimulation with MTB-specific peptides. In addition, CD4(+)CD40L(+) T cells were found to be mostly polyfunctional T cells that simultaneously produce IFN-γ, IL-2 and TNF-α and display an effector or effector memory phenotype (CD45RA(-)CD45RO(+)CCR7(-)CD62L(-)ICOS(-)). To determine the specificity of CD4(+)CD40L(+) T cells, we incubated PFCs with ESTA-6/CFP-10 peptides and sorted live CD4(+)CD40L(+) and CD4(+)CD40L(-) T cells by flow cytometry. We further demonstrated that sorted CD4(+)CD40L(+), but not CD4(+)CD40L(-) fractions, principally produced IFN-γ, IL-2, TNF-α, IL-17 and IL-22 following restimulation with ESTA-6/CFP-10 peptides. Taken together, our data indicate that the expression of CD40L on MTB-specific CD4(+) T cells could be a good marker for the evaluation and isolation of MTB-specific Th cells and might also be useful in the diagnosis of TB.