| The shock is the pathological process that the acute circulation exhaustion in the organism caused by various strong pathogenic factors for a disease effect, characterized by microcirculatory obstacle and perfusing unable in important organs of the body , eventually causes harm to the whole body. It involves the major lethal factors in all kinds of harmful symptom in various clinical section and war injuring . Owing to the high mortality rate, and mechanism is not expounded completely yet, the shock has always been attached importance in the medical science circle.According to the cause of disease the shock can be divided into several classifications; hemorrhagic shock , burn shock , traumatic shock , infectious shock , anaphylactic shock , cardiogenic shock and neurogenic shock . According to the original occurrence the shock can be classified into hypovolemic shock ,vasogenic shock and cardiogenic shock . In spite of the original cause of disease of shock is different , the effective perfusing volume reduction is the most common foundation that shock occurs , and enough blood capacity , normal blood vessel function of contracting and diastoling, and normal heart pump function can be considered the foundation of effectively irrigating flowing . The various cause of diseases do general influence the blood perfusing volume by way of the three 1 above inks .The serious infection can cause the infectious shock , especially the G~ bacteria infection, the mechanism is very complicated and is the result of many kinds of factors acting on mutually . Microcirculation theory that is put forward in the 60's 20 centuries has been established the foundation for the mechanism of shock . Though microcirculation obstacle is important for shock to occur , the injury of cell directly caused by the endotoxin often occurs before blood dynamicchange . The studying for infectious shock has gone deep into cell and molecule level since the 80s 20th century ,that has established the foundation for further expounding the mechanism, at the same time providing the new research direction for infectious shock cures .The endotoxin of G ~ bacteria locates the outside layer of the cell wall. It is divided into lipid A, core region and 0 antigen three parts from interior to outer according to the differences of chemical structure and biological activity.The endotoxin can be released into blood or directly act on many kinds of effective cells ( mono - phagocyte , neutrophil, endotheliocytes etc ) , and the free endotoxin among them is more active , about 80 times higher than that at the cell membrane , and it is the promoter of organism immunoresponsiveness.LPS irritates the organism to response and the effective cell gives rise to inflammation reaction, and the initiative cytokines to promote the inflammation is tumor necrosis factor - a and interleukin - 1. TNF - a and IL - 1 can further cause releasing the inflammation urging cytokines, such asIL-6, IL-8 , IL -11 , IL - 12 and IFN - *y , and other lipid interleukin, such as thromboxane (TX) , leukotrienes ( LTs) , platelet activation factor (PAF) and prostaglandin( PG) ,et al. , and magnify the inflammation reaction further . The LPS can also induce the produces of chemotactic factor, the adhesion molecule such as CDS 1 in endotheliocytes and E - selectin , ICAM - 1. VCAM - 1, L - selection in white blood cell, integratin, et al. It can cause monocyte and polycyte to migrate to local infectious part . Meantime LPS can also activate complement system , strengthens the ability to destroy harmful microorganisms further . In addition , LPS still can induce the epoxidase, make arachidonic acid to bring into being PGE , PGF , PGI2 and thrombus,et al .Research results has suggested that LPS can firstly combine with the endotoxin - lipopolysaccharide combination protein, and form LPS - LBPs complex in the plasma , then combine with CD14 ( LPS's receptor ) on the monocyte membrane , thus transduct LPSs signal from cell membrane into it,, and then activate tyrosine kinase ( TK )...
|
PDF Full Text Request