Evaluation of membranes for use in on-line cell separation during mammalian cell perfusion processes

Büntemeyer H, Bohme C, Lehmann J. Evaluation of membranes for use in on-line cell separation during mammalian cell perfusion processes. Cytotechnology. 1994;15(1-3):243-251.In this study two microporous hollow fibre membranes were evaluated for their use as cell retention device in continuous perfusion systems. A chemically modified permanent hydrophillic PTFE membrane and a hydrophilized PP membrane were tested. To investigate the filtration characteristic under process conditions each membrane was tested during a long term perfusion cultivation of a hybridoma cell line. In both cultivations the conditions influencing membrane filtration (e.g. transmembrane flux) were kept constant. Filtration behaviour was investigated by monitoring transmembrane pressure and protein permeability. Transmembrane pressure was measured on-line with an autoclavable piezo-resistive pressure sensor. Protein permeability was determined by quantitative evaluation of unreduced, Coomassie stained SDS-PAGE. The membrane fouling process influences the filtration characteristic of both membranes in a different way. After fermentation the PP membrane was blocked by a thick gel layer located in the big outer pores of the asymmetric membrane structure. The hydraulic resistance was higher but the protein permeability was slightly better than of the PTFE membrane. For this reason the PP membrane should be preferred. On the other hand, transmembrane pressure decreases slower when the PTFE membrane is used, which favours this membrane for long term cultivations, especially when low molecular weight proteins (<30 KD) are produced

Magnetic Resonance Imaging Measures of Brain Structure to Predict Antidepressant Treatment Outcome in Major Depressive Disorder

10.1016/j.ebiom.2014.12.002EBioMedicine2137-4

Emotional attribution in high-functioning individuals with autistic spectrum disorder: A functional imaging study

OBJECTIVE: To determine whether expertise in the attribution of emotion from basic facial expressions in high-functioning individuals with autistic spectrum disorder (ASD) is supported by the amygdala, fusiform, and prefrontal regions of interest (ROI) and is comparable to that of typically developing individuals. METHOD: Functional magnetic resonance imaging scans were acquired from 14 males with ASD and 10 matched adolescent controls while performing emotion match (EM) (perceptual), emotion label (EL) (linguistic), and control tasks. Accuracy, response time, and average activation were measured for each ROI. RESULTS: There was no significant difference in accuracy, response time, or ROI activation between groups performing the EL task. The ASD group was as accurate as the control group performing the EM task but had a significantly longer response time and lower average fusiform activation. CONCLUSIONS: Expertise in the attribution of emotion from basic facial expressions was task-dependent in the high-functioning ASD group. The hypothesis that the high-functioning ASD group would be less expert and would have reduced fusiform activation was supported in the perceptual task but not the linguistic task. The reduced fusiform activation in the perceptual task was not explained by reduced expertise; it is therefore concluded that reduced fusiform activation is associated with the diagnosis of ASD

Localization and targeting of SCG10 to the trans-Golgi apparatus and growth cone vesicles.

SCG10 is a membrane-associated, microtubule-destabilizing protein of neuronal growth cones. Using immunoelectron microscopy, we show that in the developing cortex of mice, SCG10 is specifically localized to the trans face Golgi complex and apparently associated with vesicular structures in putative growth cones. Consistent with this, subcellular fractionation of rat forebrain extracts demonstrates that the protein is enriched in the fractions containing the Golgi apparatus and growth cone particles. In isolated growth cone particles, SCG10 was found to be particularly concentrated in the growth cone vesicle fraction. To evaluate the molecular determinants of the specific targeting of SCG10 to growth cones, we have transfected PC12 cells and primary neurons in culture with mutant and fusion cDNA constructs. Deletion of the amino-terminal domain or mutations within this domain that prevented palmitoylation at cysteines 22 and 24 abolished Golgi localization as well as growth cone targeting, suggesting that palmitoylation of the amino-terminal domain is a necessary signal for Golgi sorting and possibly transport of SCG10 to growth cones. Fusion proteins consisting of the amino-terminal domain of SCG10 and the cytosolic proteins stathmin or glutathione-S-transferase colocalized with a Golgi marker, alpha-mannosidase II, and accumulated in growth cones of both axons and dendrites. These results reveal a novel axonal/dendritic growth cone targeting sequence that involves palmitoylation