The Study On The Effect Of Long-pulsed 1064nm Nd:YAG Laser On Chromblastomycosis

BackgroundAt present,there is no gold standard for the treatment of Chromoblastomycosis.The current treatment methods mainly comes from open clinical research and expert opinions.Systemic antifungal drugs,are expensive and require long-term use,which also has a great effect on liver and kidney function.Physical therapy are lack of clinical control experiments,which mainly come from case reports.The long-pulsed 1064nm Nd:YAG laser has a depth of action deep to the dermis layer and is selectively absorbed by hemoglobin and pigments,and its application extends to fungal skin diseases,currently.ObjectiveTo observe the effect of long-pulsed 1064nm Nd:YAG lasers on Chromoblastomycosis.MethodsIn vitro,a clinical strain of Chromoblastomycosis,was inoculated into small culture.After long-pulsed 1064 nm Nd:YAG laser irradiation,the immediate effect of laser on fungi was observed under an optical microscope.The fungal colonies were irradiated with the laser,and the colony growth curve was recorded after the irradiation.In an animal experiment,Wistar rats were injected subcutaneously with the fungus suspension of F.monophora.The lesion diameters of 15 days,30 days,45 days,60 days,and 90 days were recorded with a caliper.Rats were randomly divided into a control group and an experimental group on the 30th day.Control group was non-treated.The experimental group irradiated the lesion with a long-pulsed 1064 nm Nd:YAG laser twice a week for 8 times.Fungal culture and pathological examination was carry out at the experimental group for 45 days and 60 days;the control group for 30 days,45 days,60 days,and 90 days.ResultIn vitro,long-pulsed 1064nm Nd:YAG laser was irradiated the fungal in the small culture.Under the microscope,the central round defect of the colony at the irradiation site was observed,the boundary of the defect was blurred,and the surrounding fungal cell wall was dissolved.After laser irradiation,there were black colonies growing in the control group and the experimental group.The colonies gradually increased with the increase of culture time.From the first day to the fifth day,the average diameter of the experimental group was smaller than that of the control group;the average diameter of the experimental group and the control group were equal on the 6th and 7th day,and the border colony of the experimental group was unclear,which was fusiform,while the border of the control group was clear,and the colony was oval.On the 8th and 9th day,the colony diameter of the experimental group was larger than that of the experimental group(P=0.1634>0.05).In the experimental group,a large number of black satellite-like colonies were surrounded by colonies,and the colonies of the control group were clear and round.In the animal experiment,after subcutaneous inoculation of fungal suspension on the back of Wistar rats,nodules appeared subcutaneously around 7 days,gradually increasing and the maximum size appeared around 30 days,and lesions were stable from 30 days to 60 days.Skin lesions were significantly reduced after 60 days.It was close to normal skin at 90 days,but the fungal culture was still positive,and the muriform cells was still visible in the pathology.Therefore,laser intervention was performed for 30 to 60 days of skin lesions.In the control group,the average diameter of lesions at 30,45,and 60 days were 8.0 mm,6.58 mm,and 5.17 mm,respectively.In the histopathology,inflammatory granuloma is formed in the dermis which mainly infiltrated with tissue cells and neutrophil.The average diameter of skin lesions in the experimental group at 30,45,and 60 days were 7.93 mm,5.64 mm,and 4.7 mm,respectively.In the pathology,Inflammatory granuloma is formed in the dennis which mainly infiltrated with lymphocytic.The fungal cultures in the control group and the experimental group were all positive,and the muriform cells were observed in the pathology.ConclusionWhen the laser irradiates the fungi,it immediately produces a thermal effect on the fungus,and the fungal protein is denatured.For the colony growth curve,because of the heating effect of the laser on the culture medium and the splash of the fungus leads to an increase in the diameter of the colony of the fungus,it is not clear that if the laser can inhibit the growth of the fungus.Animal models of Chromblastomycosis can be successfully prepared by subcutaneous inoculation of the fungus suspension on the back skin of Wistar rats.Long-pulsed1064 nm Nd:YAG laser irradiation of skin lesions in the animal model of Wistar rats of Chromblastomycosis can change the immune response and may promote the healing of skin lesions.