Process intensification strategies toward cell culture-based high-yield production of a fusogenic oncolytic virus

We present a proof-of-concept study for production of a recombinant vesicular stomatitis virus (rVSV)-based fusogenic oncolytic virus (OV), rVSV-Newcastle disease virus (NDV), at high cell densities (HCD). Based on comprehensive experiments in 1 L stirred tank reactors (STRs) in batch mode, first optimization studies at HCD were carried out in semi-perfusion in small-scale cultivations using shake flasks. Further, a perfusion process was established using an acoustic settler for cell retention. Growth, production yields, and process-related impurities were evaluated for three candidate cell lines (AGE1.CR, BHK-21, HEK293SF)infected at densities ranging from 15 to 30 × 10⁶ cells/mL. The acoustic settler allowed continuous harvesting of rVSV-NDV with high cell retention efficiencies (above 97%) and infectious virus titers (up to 2.4 × 10⁹ TCID₅₀/mL), more than 4–100 times higher than for optimized batch processes. No decrease in cell-specific virus yield (CSVY) was observed at HCD, regardless of the cell substrate. Taking into account the accumulated number of virions both from the harvest and bioreactor, a 15–30 fold increased volumetric virus productivity for AGE1.CR and HEK293SF was obtained compared to batch processes performed at the same scale. In contrast to all previous findings, formation of syncytia was observed at HCD for the suspension cells BHK 21 and HEK293SF. Oncolytic potency was not affected compared to production in batch mode. Overall, our study describes promising options for the establishment of perfusion processes for efficient large-scale manufacturing of fusogenic rVSV-NDV at HCD for all three candidate cell lines.     

Ataxia with Vitamin E Deficiency: Refinement of Genetic Localization and Analysis of Linkage Disequilibrium by Using New Markers in 14 Families

Ataxia with vitamin E deficiency (AVED) is an autosomal recessive disease characterized clinically by neurological symptoms with often striking resemblance to those of Friedreich ataxia. This disorder has been reported previously as familial isolated vitamin E deficiency. We have mapped recently the AVED locus to a 5-cM confidence interval on chromosome 8q by homozygosity mapping in six Mediterranean families. We have now analyzed six new and two previously described families and demonstrate genetic homogeneity despite important clinical variability and wide geographic origins. Analysis of nine new tightly linked microsatellite markers, including four characterized in this study, revealed a predominant but not unique mutation in northern African populations, where this condition is more frequent. Haplotype analysis but also classical recombinations allowed us to refine the AVED position to a 1-cM interval. A YAC contig over this interval was constructed from marker STSs and YAC fingerprint data, in order to facilitate the search of the AVED gene.     

A comparison of some pharmacological actions of prostaglandin E1, 6-oxo-PGE1 and PGI2

Some pharmacological actions of prostaglandin E1 (PGE1), 6-oxo-PGE1 and PGI2 have been studied. 6-oxo-PGE1 and PGE1 relaxed guinea-pig tracheal muscle in vitro and increased nasal patency in normal volunteers and in subjects with vasomotor rhinitis whereas PGI2 produced opposite effects. All three compounds produced bronchodilatation in the anaesthetised guinea-pig and relaxed human respiratory tract muscle in vitro. PGI2 was several times more potent than either 6-oxo-PGE1 or PGE1 against ADP-induced aggregation of human and baboon platelets in vitro. Intravenous 6-oxo-PGE1 in the baboon caused an ex vivo inhibition of platelet aggregation, but the EC50 was 7.7 times that of PGI2. As a vasodepressor in the baboon 6-oxo-PGE1 and PGI2 were equipotent. Thus with the exception of the vasodepressor effect, the actions of 6-oxo-PGE1 qualitatively and quantitatively resembled those of the structurally related PGE1 rather than those of PGI2.     

Immunohistochemical localization of procollagens. II. Electron microscopic distribution of procollagen I antigenicity in the odontoblasts and predentin of rat incisor teeth by a direct method using peroxidase linked antibodies.

In an attempt to locate procollagen I in rats odontoblasts, antibodies raised in rabbits were purified by affinity methods and linked to peroxidase. They were then incubated with chopped slices from the growing end of rat incisor teeth. The antibodies binding to the antigens in the slices were visualized by reacting the peroxidase moiety with diaminobenzidine in the presence of hydrogen peroxide. The slices were then embedded in Epon and sectioned for ultrastructural study. Within odontoblasts, the immunostaining indicative of procollagen I antigenicity is moderate in rough endoplasmic reticulum cisternae, strong in spherical and cylindrical Golgi distensions, intense in secretory granules, and variable in lysosomal structures. In predentin, immunostaining is intense close to the odontoblast layer, but decreases gradually in a distal direction. Hence, procollagen I (and/or substances endowed with similar antigenicity such as pro alpha (I) chains and procollagen fragments) is present: 1) along the intracellular pathway of collagen precursors where its concentration gradually increases to reach a maximum in secretory granules; 2) in predentin, into which it is released from the granules for transformation into nonimmunoreactive collagen I; and 3) in lysosomal structures where some of it is hydrolyzed.     

Structural investigation of bacteriorhodopsin and some of its photoproducts by polarized Fourier transform infrared spectroscopic methods-difference spectroscopy and photoselection

The direction of selected IR-transition moments of the retinal chromophore of bacteriorhodopsin (BR) and functional active amino acid residues are determined for light- and dark-adapted BR and for the intermediates K and L of the photocycle. Torsions around single bonds of the chromophore are found to be present in all the investigated BR states. The number of twisted single bonds and the magnitude of these torsions decreases in the order K, L, light-adapted BR, dark-adapted BR. In the last, only the C₁₄—C₁₅ single bond is twisted. The orientation of molecular planes and chemical bonds of such protein side chains, which are perturbed during the transition of light-adapted BR to the respective intermediates, are deduced and the results compared with the current three dimensional model of BR. Trp 86 and Trp 185 are found to form a rigid part of the protein, whereas Asp 96 and Asp 115 perform molecular rearrangements upon formation of the L-intermediate.     

中国寄生云杉的顶裂盘菌及其无性阶段

本文报道了寄生在云杉上的中国新记录种顶裂盘菌(Lophophacidium hyperboreumLagerb.);首次发现了这个种的无性型座壳梭孢属(Apostrasseria sp.),证实了融雪前病株针叶上有表生的菌丝和小菌核;查清了它是新疆云杉林中的广布种,引致云杉雪枯病;发现了新分布区,地理分布范围在75°—94°E,37°40′—49°N;发现了新寄主,多土的西伯利亚云杉(Picea obovata Ledeb.)和引进的青海云杉(P.crassifolia Kom.)、川西云杉(P.balfourianaRehd.et Wils.)。     

A rapid method for the detection of tryptophanase in anaerobic bacteria

A total of 633 anaerobic bacteria were examined for tryptophanase production using a rapid method which distinguishes within 5 to 180 minutes between anaerobes that contain tryptophanase and those that do not. Of the 196 tryptophanase-positive isolates tested, 99% showed tryptophanase activity within 2 hours as compared with 94.4% in 24 hours by a conventional method. A total of 299 tryptophanase-negative organisms were tested. Ninety three percent of these remained negative after 24 hours as compared with 95.3% when tested with a 24-h conventional method. Additional information was obtained on the sensitivity of this test and the time-dependent production of indole by tryptophanase.     

植被覆盖度对夏季降温效应的影响——以内蒙古为例

随着全球变暖的加剧,区域热环境问题日益凸显,植被的降温作用逐渐得到广泛关注。目前已有的研究多从样地尺度分析不同类型植被的降温效应。而区域尺度的研究多从定性的角度揭示地表温度与植被覆盖的关系,对评估植被的实际降温效应具有一定的局限性。以内蒙古为研究区,以MODIS地表温度数据为基础,采用近邻分析法,将森林、灌丛和草地的MODIS地表温度与相邻5km范围内的低覆盖地表作为对照,分析植被的降温效应以及植被覆盖度对降温效应的影响。从2015年7月地表温度平均值的结果来看,降温度数在蒙东、蒙中和蒙甘区均呈现森林>灌丛>草地。森林的降温范围在0.67-1.03℃,灌丛为0.60-0.95℃,草地为0.47-0.86℃。植被降温度数与植被覆盖度的回归拟合为对数分布,均呈显著正相关（P<0.01）。且在不同的植被覆盖度范围内植被降温效应具有显著差异,植被覆盖度水平较低时（<40%）,植被覆盖度的增加能更显著地降低地表温度。从整体来看,植被覆盖度每增加10%,森林降温0.12-0.39℃;灌丛降温0.1-0.2℃;草地降温0.049-0.075℃。综上,内蒙古作为全球气候变化最为敏感的区域之一,研究植被的夏季降温效应能够为内蒙古的气候调节服务评估提供重要的理论支撑及案例参考。     

不同方式处理牛粪对大豆生长和品质的影响

大型养殖场粪便堆积造成严重的环境污染,对这类废弃物开展资源化利用研究具有重要生态学和经济学意义。以不施肥料处理(CK)为对照,研究了生态养殖场牛粪经腐熟(DD)和蚯蚓处理(RD)后对大豆生长与品质的影响。研究表明:生态养殖场牛粪经过两种处理后,在一定施用量范围(DD≤30 t/hm2,RD≤45 t/hm2)内,可显著增加大豆株高、分株数、干物质积累,促进植株生长,增加单株荚数、籽粒数、籽粒重,提高大豆产量(P<0.01)。施入腐熟牛粪30 t/hm2株高和单株结荚数比CK分别增加24.2 cm、63%;经蚯蚓处理后,可以提高牛粪施用量的上限,施入蚯蚓处理过的牛粪45 t/hm2时产量最高、单株结荚数最多,比CK分别增加72%和75%(P<0.01);施入蚯蚓处理过的牛粪15 t/hm2时,粗蛋白含量、蛋脂总量最高,比CK分别增加7%和6%(P<0.01)。本研究可为大型养殖场牛粪资源化利用提供科学依据。