ABSTRACT
The collaterals are branches of the meridians and vessels system, and have the roles of connecting upper-lower and interior-exterior portions of the body, the characteristics of two-way flow in supporting the operation of Qi and blood, and the functions of material exchange and metabolism. The brain is the intersection of the Yang meridians. Crisscross brain collaterals permeate Qi and blood to enrich the brain, and spread Yang Qi, in order to warm the brain-mind, and provide material basis and source power to the " brain governing mind" . Under pathological conditions, cerebral collaterals are blocked, and toxic pathogens are endogenous, resulting in " toxin damaging brain collaterals" . This theory is not only applied to the study of stroke pathogenesis, but also extended to other encephalopathy, such as dementia, which promoted the development of the theory of pathogenesis in traditional Chinese medicine. Recently, a " glymphatic system" was discovered in the brain, which is an exchange flow system of cerebrospinal fluid-brain interstitial fluid mediated by astrocyte. The glymphatic system transports nutrients and neuroactive substances, such as glucose, lipids, electrolytes and apolipoprotein E in the cerebrospinal fluid, to brain tissue, and also removes metabolic products (such as lactic acid), soluble proteins (such as β-amyloid protein and Tau protein) from the brain and foreign bodies, which are important liquid flow systems that maintain the homeostasis of the brain. The discovery of the glymphatic system provides a new perspective for the study of pathological mechanism of neurological diseases, and may become a new target for interventions in neurological diseases, such as cerebrovascular diseases and neurodegenerative diseases. As a widely distributed cerebral metabolic waste removal way and material delivery system, the lymphatic system may be the biological foundation of " brain collateral" disease, and a cross point of understanding on " toxin impairing brain collaterals" by Western and traditional Chinese medicine. The study based on the glymphatic system will give a more rational explanation on " toxic damage to brain collaterals" .
ABSTRACT
In genetic engineering antibodies,Fabs antibodies have many advantages,such as lower relative molecular mass, specific tissue distribution and lower immunogenicity, which have made Fabs antibodies the research hotspot for the past few decades. Besides the widely used enzymatic generation, multiple expression systems which include E. coU. and insects are used in the generation of Fabs antibodies. E. coli. expression system is most thoroughly explored and has been used in the preparation of clinical Fabs drugs. There are six Fab drugs that have been approved by FDA, such as certolizumabpegol and many Fabs are still in clinical research. This review discusses the recent research progress of Fabs drugs, including Fabs' structure and characteristics, the generation and expression of Fabs, strategies to increase production and clinical applications, with the emphasis on generation, expression and clinical applications.