| Endotoxin(ET) comes mainly from cell wall of Gram-negative bacteria, its main component is lipopolysaccharides(LPS) with a Molecular Weight(MW) of 108dalton,which can be broken down and degraded into two types of subunits, one is a smooth-type with MW of 10,000,the other one is a rough-type with MW of 6,000,or even into smaller fragments with MW of <2,000,which may enter blood circulation. ET resists heat,115℃ can only kill the body of bacteria rather than ET itself either 180℃ ×2hr or 250℃×1/2hr can eliminate ET. A small quantity of ET enters blood stream may stimulate body's immune system and strengthen non-specific resistance. If its quantity exceeds 40ng/l, it may induce and release mediators such as anaphylatoxin, inflammatory cell factors, cause pathophysiological effects, the clinical manifestations of these effects are chill, fever, hypotension, DIC, etc.The problem of endotoxin reactions has increasing by caused great concern in the field of renal diseases, especially in hemodialysis. Recent studies have discovered that the endotoxin and its fragments contaminated in the dialysate can penetrate the high-flox or even conventional low-flox dialyzer membranes and result in various acuteand chronic complication in-patients who received dialysis.Patients with chronic renal failure and maintained with blood dialysis always has an abnormal level of cytokines in their peripheral blood, which may be associated to the factors of hemodialysis. In addition to the raw materials of dialyzer, the contamination problem of bacterial endotoxin in dialysate has gradually caused great concern in recent years. Scholars at home and abroad have realized that the endotoxin in the dialysate may stimulate monocytes to release some cytokines in HD patients.ln1983,"IL-1 hypothesis" was put forward by Henderson, upon this hypothesis, IL-1,etc,play an important role in the development of HD complications;IL-1 ,TNF- a and IL-6 had been considered to play to play an inducement in the development of acute complications, moreover, the latter two cytokines had been regarded as intrinsic Pyrogens,IL-1 and TNF- a could cause hypotension, leukocytopenia, and fever.At present, more and more scholars tend to agree with the following view points: The production of cytokines includes several steps such as transcript, translation and release, each step needs special control signal; under the stimulation by contacting blood films,C5a, etc, PBMC stands at a pre-activated status for expressing the gene of cytokines, it needs a 2nd signal e.g. endotoxin etc. to stimulate so as to synthesis a mature-form proteins and release them into the outside of cells.So far, endotoxin is the most important factor known to be the inducer of IL-1 ,TNF- a ,etc, which can activate cytokine cascade reactions and leads to systemicinflammatory reaction syndrome(SIRS),multiple organ dysfunction syndrome(MODS),or even multiple organ failure(MOF).Multiple organ dysfunction syndrome(MODS) is the most severe complication after wound and infection. Recent studies have found that among the infective factors that induce MODS, endotoxin plays an important role. Based upon many experimental observations, it was inferred that endotoxemia-bacterial translocation might be one of the important causes of the infections that was difficult to be controlled in clinical practice. And it has also been suggested that there must be certain intrinsic association with the excessive inflammatory reaction and organ's functional impairment following severe wound.The prevention of endotoxemia lies in reducing bacterial infection or contamination, and eliminating potential infection or contaminated bacteria; when an endotoxemia occurs, the effective antibiotic treatment ought to be strengthened so as to arrest the sustained rise of endotoxin. Chinese medicine and pharmacology are a great treasure-house, it can play an important role in dealing with these situations.This experiment attempts to study the effect of Astragalus root(Radix Astragali) and rhubarb (Radix... |
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