Effects of storage time prolongation on in vivo and in vitro characteristics of 4°C-stored platelets.

Background: Cold (4°C)-stored platelets are currently under investigation for transfusion in bleeding patients. It is currently unknown how long cold-stored platelets can be stored for clinical applications.

Study Design And Methods: Twenty three subjects were recruited.

Platelets stored in whole blood at 4°C: in vivo posttransfusion platelet recoveries and survivals and in vitro hemostatic function.

Background: Ordinarily, whole blood (WB) is separated into components before storage. We assessed the posttransfusion viability and function of platelets (PLTs) if they were stored within WB at 4°C.

Study Design And Methods: Whole blood was obtained from 30 normal subjects and stored at 4°C without agitation for 12 days and for 10, 15, or 22 days with agitation.

In vivo viability of extended 4°C-stored autologous apheresis platelets.

Background: The current 5-day storage time of room temperature (22°C)-stored platelets (RSPs) severely limits platelet (PLT) availability. Extended cold (4°C)-stored PLTs (CSPs) are currently being investigated for actively bleeding patients. However, we currently do not know how to best store PLTs in the cold for extended periods of time.

In vitro analysis of chloroplast protein import.

This unit describes protocols for isolating chloroplasts from pea (Pisum sativum) and Arabidopsis thaliana for the study of nuclear-encoded plastid precursor proteins. Chloroplasts from both preparations are competent for the in vitro import of recombinant preproteins synthesized using in vitro translation systems derived from reticulocyte or wheat germ lysates. These assays can be used to test whether a particular protein is targeted to chloroplasts, for analyzing the suborganellar location of newly imported preproteins, or to study the mechanism of import itself.

Tic40, a membrane-anchored co-chaperone homolog in the chloroplast protein translocon.

The function of Tic40 during chloroplast protein import was investigated. Tic40 is an inner envelope membrane protein with a large hydrophilic domain located in the stroma. Arabidopsis null mutants of the atTic40 gene were very pale green and grew slowly but were not seedling lethal.

In vivo analysis of the role of atTic20 in protein import into chloroplasts.

The import of nucleus-encoded preproteins into plastids requires the coordinated activities of membrane protein complexes that facilitate the translocation of polypeptides across the envelope double membrane. Tic20 was identified previously as a component of the import machinery of the inner envelope membrane by covalent cross-linking studies with trapped preprotein import intermediates. To investigate the role of Tic20 in preprotein import, we altered the expression of the Arabidopsis Tic20 ortholog (atTic20) by antisense expression.

Digalactosyldiacylglycerol synthesis in chloroplasts of the Arabidopsis dgd1 mutant.

Galactolipid biosynthesis in plants is highly complex. It involves multiple pathways giving rise to different molecular species. To assess the contribution of different routes of galactolipid synthesis and the role of molecular species for growth and photosynthesis, we initiated a genetic approach of analyzing double mutants of the digalactosyldiacylglycerol (DGDG) synthase mutant dgd1 with the acyltransferase mutant, act1, and the two desaturase mutants, fad2 and fad3.