The Research On Pathology Of Neuropathy And Vasculopathy Of Diabetic Foot

Diabetic foot(DF) is one of the quadr-complications in the advancedstage of diabetes mellitus. Diabetic peripheral neuropathy(DPN) anddiabetic peripheral angiopathy(DPA) are crucial patho-foundation ofdiabetic foot. Researches show that, there are evident pathobiologicalchanges in peripheral vessels and peripheral nerves of DF patients. Theseverity of peripheral vessels and peripheral nerves has correlation with therisk of the amputation of DF patients. The treatment for DF lay particularemphasis on expanding blood vessels, which not lay equal attention onnutrition nerve. At present, most of results come from animal, but researchbased on human tissue is seldom. We obtain the proximal and distal nerveand vessel from the DF patients for the observation of the pathobiologicalchanges, to presume the interrelationship between DPN and DPA , to huntthe etiopathogenesis of DF further, and to provide theoretical basis forpreventing and theraping the amputation of DF.Selected patients who had undertaken high amputation in the BoneSurgery department of the first affiliated hospital of the He Bei NorthUniversity from September 2008 to December 2010 as the reearch objectsin our experiment. And they all had DPN and DPA.There are 22 patients(12males and 10 females) in our study (mean age, 65.3±7.5 years). Obtaineddistal nerve(the posterior tibial nerve from 10 centimeter away from anklejoint), proximal nerve(the sciatic nerve of the level of amputation ), distalvessel(the arteria tibialis posterior from 10 centimeter away from anklejoint)and proximal vessel(the femoral artery of the level ofamputation)when high amputation operation was progressing. Adopted thefollow methods to observe the change in pathology of proximal and distal nerve and vessel:1. The samples were put in the solution of 10% formalin, and thenembedded in paraffin, the sections were used to observe the general of thenerve and vessel tissue by HE staining and the myelin sheath structure ofnerve by Loyez staining. And then counted the nerve fiber's quantity,myelin sheath's area and density under light microscope.2. To observe the expression of protein kinase c–βⅡ(PKC-βⅡ)andS-100 in femoral nerve by immunohistochemistry and count the quantityunder light microscope in unit area, to observe the expression ofInsulin-like growth factor-1(IGF-1) in femoral nerve by immunohistochemistryand count the percent of positive cells under light microscope inorder to compare the difference between distal and proximal nerve.Observed the following result by our experiment:1. (1)HE and Loyez staining: Found that there are an evidentpathobiological changes in proximal and distal nerve and vessel among allthe samples. Proximal nerve: The appearance and diameters of nerve fiberand cylinder are not uniformity, part of myelinated axons axis were atrophyor disappeared, axis cylinder anachromasis and degeneration can be seenby chance, the density of myelin sheath is aslo not uniformity, a part ofmyelin sheath has shallot change, regenerate axis cylinders show up, andthe numbers of small vessels in nerve tract increase, small vessel wallsthicken. Distal nerve: The fiber is sparse obviously, diameters of which arenot uniformity apparently. There is obvious myelinoclasis in the fibers. Theregeneration clump is seldom seen, the quantity of small vessels in nervetract decrease, and the deformity and thickening of vessel walls get worse.The variance of the nerve fiber's quantity, total area and density betweenthe proximal and distal nerve has statistical significance(P<0.05)；(2)There is an evident different pathological change period betweenproximal and distal vessel by HE staining: The proximal vessels mainrepresent in atherosclerotic fatty streak stage by light microscope. The vascular intima can see slightly eminentia, under which there are foam cellswith lipidic, scattered lymphocytes and hyperplastic smooth muscle cells.The proximal vessels main represent in atheromatous plaque stage. Thesurface of vascular intima can see fibrio-cap constructed by hyperplasticfibrous tissue, the bottom and border of which have hyperplastichyperplastic granulation tissue,and the periphery of vascular intima havesmall amotnts of foam cells and lymphocytes infiltration.2. Results of immunohistochemistry: The expression of IGF-1, PKC-βⅡand S-100 are both positive in proximal and distal nerve. The varianceshave statistical significance(P<0.05).The conclusion draw from our experiment and the experimentalresults:1. Results obtained from light microscope prove that, there aresignificant pathological changes in the proximal and distal nerve and vessel.There is comparability in pathological changes of the proximal and distalnerve and vessel.2. There is correlation between DPN and DPA, the severity of DPNmay determinate by the degree of the angiodystrophy. And the DPN canaffect diastolic function of vessels to some degree.3. Preventing and theraping DF should put equal attention onexpanding blood vessels and nutrition nerve in the clinic.