[Analysis of Quality Management of in Vitro Diagnostic Reagent Clinical Trials].

Clinical trial is an important step of in vitro diagnostic reagents research and development. Based on the Guiding Principles and the key points of inspect on the spot, combined with the actual work experience, the article focuses on the prominent problems in the whole process of in vitro diagnostic reagent clinical trials. It is helpful to improve the level of hospital drug clinical trial centre and the quality of in vitro diagnostic reagent clinical trials by analyzing the issues.

Protein Aggregation and Performance Optimization Based on Microconformational Changes of Aromatic Hydrophobic Regions.

Protein aggregation is a key concern in biopharmaceutical development and manufacturing. There is growing interest in understanding how the changes in protein microconformation affect the aggregation behavior. This study selected several representative proteins and first manipulated microconformational changes of the aromatic hydrophobic regions of proteins, especially tryptophan residues, by using amine or guanidine additives. The effects of the interactions between the additives and proteins on the aromatic hydrophobic regions could be grouped into three categories: exposure to solvent, burial into core, and no change. The microconformational parameters of the tryptophan residue, including fluorescence peak position (λm), degree of hydrolysis, solvent accessible surface area ( SAS), and packing density ( Den), were obtained by steady-state fluorescence spectroscopy, proteolysis coupled with electrophoresis, and molecular dynamics simulation. Furthermore, the aggregation degrees of globular proteins with distinct surface aromatic hydrophobilities under mechanical stress were investigated. A strong correlation was observed between protein aggregation and the microconformational changes of the aromatic hydrophobic regions incurred by amine or guanidine additives. Protein aggregation was enhanced when the aromatic hydrophobic regions were exposed to the solvent but suppressed when the additives led to burial of the aromatic hydrophobic regions with lower-polarity microenvironment. These findings shed light on the relationship between protein aggregation and molecular conformation and paved way for future preformulation studies of therapeutic proteins.

Inhibition effect of thiol-type antioxidants on protein oxidative aggregation caused by free radicals.

This study was aimed to investigate the inhibition effect of thiol-type antioxidants on protein oxidative aggregation caused by free radicals and the underlying mechanisms using six different thiol-type antioxidants (N-acetyl-L-cysteine, methionine, taurine, alpha-lipoic acid, glutathione and thioproline), Cu2+-H2O2 as a free radical generator (mainly a hydroxyl radical generator) and bovine serum albumin as the model protein. The inhibition effect of these antioxidants on protein oxidative aggregation and protective effect against oxidative damage in mouse brain tissues were investigated using SDS-PAGE, intrinsic fluorescence, simultaneous fluorescence, thioflavin T fluorescence, Congo red absorbance and inverted microscope. The results showed that all six antioxidants could inhibit protein oxidative aggregation by scavenging free radicals. In addition, alpha-lipoic acid could also bind to proteins via hydrophobic interactions and thioproline could bind to proteins via hydrogen bonds and van der Waals forces, thereby showing much stronger inhibition effect than others. Moreover, alpha-lipoic acid and thioproline could effectively prevent oxidative damage of mouse brain tissues. These results suggest that alpha-lipoic acid and thioproline can effectively inhibit free radical-induced protein aggregation and brain damage, which are worth testing for further anti-Alzheimer properties.

AUXIN RESPONSE FACTOR 1 Acts as a Positive Regulator in the Response of Poplar to Trichoderma asperellum Inoculation in Overexpressing Plants.

Numerous Trichoderma strains have been reported to be optimal biofertilizers and biocontrol agents with low production costs and environmentally friendly properties. Trichoderma spp. promote the growth and immunity of plants by multiple means. Interfering with the hormonal homeostasis in plants is the most critical strategy. However, the mechanisms underlying plants' responses to Trichoderma remain to be further elucidated. Auxin is the most important phytohormone that regulates almost every aspect of a plant's life, especially the trade-off between growth and defense. The AUXIN RESPONSE FACTOR (ARF) family proteins are key players in auxin signaling. We studied the responses and functions of the PdPapARF1 gene in a hybrid poplar during its interaction with beneficial T. asperellum strains using transformed poplar plants with PdPapARF1 overexpression (on transcription level in this study). We report that PdPapARF1 is a positive regulator for promoting poplar growth and defense responses, as does T. asperellum inoculation. PdPapARF1 also turned out to be a positive stimulator of adventitious root formation. Particularly, the overexpression of PdPapARF1 induced a 32.3% increase in the height of 40-day-old poplar plants and a 258% increase in the amount of adventitious root of 3-week-old subcultured plant clones. Overexpressed PdPapARF1 exerted its beneficial functions through modulating the hormone levels of indole acetic acid (IAA), jasmonic acid (JA), and salicylic acid (SA) in plants and activating their signaling pathways, creating similar results as inoculated with T. asperellum. Particularly, in the overexpressing poplar plants, the IAA level increased by approximately twice of the wild-type plants; and the signaling pathways of IAA, JA, and SA were drastically activated than the wild-type plants under pathogen attacks. Our report presents the potential of ARFs as the crucial and positive responders in plants to Trichoderma inducing.