Comparison Of Local Hyperthermia And Oral Potassium Iodide Solution For Mice Sporotrichosis

IntroductionSporotrichosis is one of the most common deep mycosis. Potassium iodide orally is first choice. Local hyperthermia is often a useful adjunct. For pregnant women and patients with severe adverse reaction, local hyperthermia is the treatment of first choice. Further more, local hyperthermia is simple, economical, and less adverse.It is believed that the mechanism of local hyperthermia for sporotrichosis involves not only it's effect on the causative agent but also the immunity. Enhancing antigen presentation is one effect of hyperthermia on immunity. HSP70 has the functions of being involved in antigens presentation,as immunol adjuvant and stimulating cytokine to active DCs,etc.Cell-mediated immunity to S. schenckii antigen is a key immunologic defense mechanism that controls the infection. The function of DCs from monocytes is antigen presentation. S. schenckii can activate them to induce thl-prone immune response. In this study we observe the curative effect of local hyperemia on mice model of sporotrichosis and we also study the changes of cytokine in the lesions after heat treatment. The purpose of the current study was to find the probable mechanism of the heat.Materials and methodsPart one1,MaterialsStrain:The S. schenckii strain(CMU12993) isolated from a patent with sporotrichisis of solitary form was used throughout the study.Mice:Female Kunming mice aged 8-10 weeks (mean weight 20-22g) were purchased from the Laboratory Animal Centre of China Medical University (Shenyang, China). Forty-five mice were divided into three groups of fifteen mice. All the mice were maintained in a specific pathogen-free environment. The mice received food ad libitum. For experimental infection, forty-five mice were injected subcutaneously at two points on their tails with 0.05 ml of the yeast form suspension (108/ml).2,MethodsLocal hyperthmia:The lesions appeared about two weeks after inoculation then the tails of infected mice were locally heated by warm water. The temperature is 43℃, three times weekly, twenty minutes per time.Potassium iodide group were fed with 10% potassium iodide soltion.The control group wasn't treated. As the therapy beginning, the changes of lesions and strength of inflammatory reaction were observed. It is effective when the lesions fully receded and the skin of affected area returned to normal.3,Statistical analysisSoftware SPSS13 was used and the data was analyzed by corrected chi square test. P values less than 0.05 were considered to represent statistically significant differences.Part two1,MaterialsThe animal models and the use of local hyperthermia are same as elucidated above in the part one.2,MethodsAfter the 1st,3rd,7th,15th treatment, five animals from each group were submitted to euthanasia to obtain material from the lesions of the tail to be processed for histopathology analyses (buffered formaline at 10% was used as the fixative agent). Histology sections were stained with HE and HSP70 immunohistochemical staining was also performed.Interpretation of the immunohistochemistry slides:dark yellow cells with DAB staining are the HSP70 positive cells. In the cutaneous lesions:dark yellow the positive infiltrated cells in continuous 3 high power lens in dermis. Positive cells less than 1% is negative, positive cells has four levels:1% to 20% is weak; 25% to 50% is moderate; more than 50% is strong.3,Statistical analysisThe data was analyzed by Kruskal-Wallis H test in software SPSS13. Statistical significance was established if the two sided P value of a test was less than 0.05.ResultsPart one1,Lesions appeared about one week after inoculation. The lesions were significant from week two to week three. The characteristic lesions may be red papules, nodules and pustules then evolved to ulcers, suppuration and crust. There were no changes about the activities and diets of the mice. The lesions of the treatment group receded gradually comparable with the control group. When twelve times treatment were performed, the thermal group rate of skin lesions regression to 86.6%,and potassium iodide group to 93.3%, the effect of local hyperthermia on mice sporotrichosis lesions compared with oral potassium iodide solution is not significant statistically,comparable with 13.3% in the control group. They were significant differences in statistics.Part twoHSP70 expresses extensively in the epidermis. The basal layer is stronger and it fades gradually in the upper layers. The follicles in the dermis were also stained lightly. The staining in epidermis was no different in the normal skin, treatment group and control group. HSP70 positive cell were present in the granulomatous lesions in dermis. The pattern of HSP70staining appeared to be combination of intracellular staining in mononuclear lymphoid cells and extracellular deposition in the surrounding tissue. Statistical significance was established between the dermis of treatment group and the control group.Conclusions1. The efficacy of local hyperthermia on mice with sporotrichosis was confirmed.2. Effect of local hyperthermia on mice sporotrichosis lesions compared with oral potassium iodide solution is not significant statistically.3. The expression of HSP70 increased in granulomatous lesion of dermis after thermotherapy.