BACKGROUND Skin wounds are common injuries that affect quality of life and incur high costs.A considerable portion of healthcare resources in Western countries is allocated to wound treatment,mainly using mechanical,b...BACKGROUND Skin wounds are common injuries that affect quality of life and incur high costs.A considerable portion of healthcare resources in Western countries is allocated to wound treatment,mainly using mechanical,biological,or artificial dressings.Biological and artificial dressings,such as hydrogels,are preferred for their biocompatibility.Platelet concentrates,such as platelet-rich plasma(PRP)and platelet-rich fibrin(PRF),stand out for accelerating tissue repair and minimizing risks of allergies and rejection.This study developed PRF and PRP-based dressings to treat skin wounds in an animal model,evaluating their functionality and efficiency in accelerating the tissue repair process.AIM To develop wound dressings based on platelet concentrates and evaluating their efficiency in treating skin wounds in Wistar rats.METHODS Wistar rats,both male and female,were subjected to the creation of a skin wound,distributed into groups(n=64/group),and treated with Carbopol(negative control);PRP+Carbopol;PRF+Carbopol;or PRF+CaCl_(2)+Carbopol,on days zero(D0),D3,D7,D14,and D21.PRP and PRF were obtained only from male rats.On D3,D7,D14,and D21,the wounds were analyzed for area,contraction rate,and histopathology of the tissue repair process.RESULTS The PRF-based dressing was more effective in accelerating wound closure early in the tissue repair process(up to D7),while PRF+CaCl_(2) seemed to delay the process,as wound closure was not complete by D21.Regarding macroscopic parameters,animals treated with PRF+CaCl_(2) showed significantly more crusting(necrosis)early in the repair process(D3).In terms of histopathological parameters,the PRF group exhibited significant collagenization at the later stages of the repair process(D14 and D21).By D21,fibroblast proliferation and inflammatory infiltration were higher in the PRP group.Animals treated with PRF+CaCl_(2) experienced a more pronounced inflammatory response up to D7,which diminished from D14 onwards.CONCLUSION The PRF-based dressing was effective in accelerating the closure of cutaneous wounds in Wistar rats early in the process and in aiding tissue repair at the later stages.展开更多
BACKGROUND Understanding the humoral response pattern of coronavirus disease 2019(COVID-19)is one of the essential factors to better characterize the immune memory of patients,which allows understanding the temporalit...BACKGROUND Understanding the humoral response pattern of coronavirus disease 2019(COVID-19)is one of the essential factors to better characterize the immune memory of patients,which allows understanding the temporality of reinfection,provides answers about the efficacy and durability of protection against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),and consequently helps in global public health and vaccination strategy.Among the patients who became infected with SARS-CoV-2,the majority who did not progress to death were those who developed the mild COVID-19,so understanding the pattern and temporality of the antibody response of these patients is certainly relevant.AIM To investigate the temporal pattern of humoral response of specific immunoglobulin G(IgG)in mild cases of COVID-19.METHODS Blood samples from 191 COVID-19 real-time reverse transcriptase-polymerase chain reaction(RT-qPCR)-positive volunteers from the municipality of Toledo/Paraná/Brazil,underwent two distinct serological tests,enzyme-linked immunosorbent assay,and detection of anti-nucleocapsid IgG.Blood samples and clinicoepidemiological data of the volunteers were collected between November 2020 and February 2021.All assays were performed in duplicate and the manufacturers'recommendations were strictly followed.The data were statistically analyzed using multiple logistic regression;the variables were selected by applying the P<0.05 criterion.RESULTS Serological tests to detect specific IgG were performed on serum samples from volunteers who were diagnosed as being positive by RT-qPCR for COVID-19 or had disease onset in the time interval from less than 1 mo to 7 mo.The time periods when the highest number of participants with detectable IgG was observed were 1,2 and 3 mo.It was observed that 9.42%of participants no longer had detectable IgG antibodies 1 mo only after being infected with SARS-CoV-2 and 1.57%were also IgG negative at less than 1 mo.At 5 mo,3.14%of volunteers were IgG negative,and at 6 or 7 mo,1 volunteer(0.52%)had no detectable IgG.During the period between diagnosis by RT-qPCR/symptoms onset and the date of collection for the study,no statistical significance was observed for any association analyzed.Moreover,considering the age category between 31 and 59 years as the exposed group,the P value was 0.11 for the category 31 to 59 years and 0.32 for the category 60 years or older,showing that in both age categories there was no association between the pair of variables analyzed.Regarding chronic disease,the exposure group consisted of the participants without any comorbidity,so the P value of 0.07 for the category of those with at least one chronic disease showed no association between the two variables.CONCLUSION A temporal pattern of IgG response was not observed,but it is suggested that immunological memory is weak and there is no association between IgG production and age or chronic disease in mild COVID-19.展开更多
文摘BACKGROUND Skin wounds are common injuries that affect quality of life and incur high costs.A considerable portion of healthcare resources in Western countries is allocated to wound treatment,mainly using mechanical,biological,or artificial dressings.Biological and artificial dressings,such as hydrogels,are preferred for their biocompatibility.Platelet concentrates,such as platelet-rich plasma(PRP)and platelet-rich fibrin(PRF),stand out for accelerating tissue repair and minimizing risks of allergies and rejection.This study developed PRF and PRP-based dressings to treat skin wounds in an animal model,evaluating their functionality and efficiency in accelerating the tissue repair process.AIM To develop wound dressings based on platelet concentrates and evaluating their efficiency in treating skin wounds in Wistar rats.METHODS Wistar rats,both male and female,were subjected to the creation of a skin wound,distributed into groups(n=64/group),and treated with Carbopol(negative control);PRP+Carbopol;PRF+Carbopol;or PRF+CaCl_(2)+Carbopol,on days zero(D0),D3,D7,D14,and D21.PRP and PRF were obtained only from male rats.On D3,D7,D14,and D21,the wounds were analyzed for area,contraction rate,and histopathology of the tissue repair process.RESULTS The PRF-based dressing was more effective in accelerating wound closure early in the tissue repair process(up to D7),while PRF+CaCl_(2) seemed to delay the process,as wound closure was not complete by D21.Regarding macroscopic parameters,animals treated with PRF+CaCl_(2) showed significantly more crusting(necrosis)early in the repair process(D3).In terms of histopathological parameters,the PRF group exhibited significant collagenization at the later stages of the repair process(D14 and D21).By D21,fibroblast proliferation and inflammatory infiltration were higher in the PRP group.Animals treated with PRF+CaCl_(2) experienced a more pronounced inflammatory response up to D7,which diminished from D14 onwards.CONCLUSION The PRF-based dressing was effective in accelerating the closure of cutaneous wounds in Wistar rats early in the process and in aiding tissue repair at the later stages.
文摘BACKGROUND Understanding the humoral response pattern of coronavirus disease 2019(COVID-19)is one of the essential factors to better characterize the immune memory of patients,which allows understanding the temporality of reinfection,provides answers about the efficacy and durability of protection against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),and consequently helps in global public health and vaccination strategy.Among the patients who became infected with SARS-CoV-2,the majority who did not progress to death were those who developed the mild COVID-19,so understanding the pattern and temporality of the antibody response of these patients is certainly relevant.AIM To investigate the temporal pattern of humoral response of specific immunoglobulin G(IgG)in mild cases of COVID-19.METHODS Blood samples from 191 COVID-19 real-time reverse transcriptase-polymerase chain reaction(RT-qPCR)-positive volunteers from the municipality of Toledo/Paraná/Brazil,underwent two distinct serological tests,enzyme-linked immunosorbent assay,and detection of anti-nucleocapsid IgG.Blood samples and clinicoepidemiological data of the volunteers were collected between November 2020 and February 2021.All assays were performed in duplicate and the manufacturers'recommendations were strictly followed.The data were statistically analyzed using multiple logistic regression;the variables were selected by applying the P<0.05 criterion.RESULTS Serological tests to detect specific IgG were performed on serum samples from volunteers who were diagnosed as being positive by RT-qPCR for COVID-19 or had disease onset in the time interval from less than 1 mo to 7 mo.The time periods when the highest number of participants with detectable IgG was observed were 1,2 and 3 mo.It was observed that 9.42%of participants no longer had detectable IgG antibodies 1 mo only after being infected with SARS-CoV-2 and 1.57%were also IgG negative at less than 1 mo.At 5 mo,3.14%of volunteers were IgG negative,and at 6 or 7 mo,1 volunteer(0.52%)had no detectable IgG.During the period between diagnosis by RT-qPCR/symptoms onset and the date of collection for the study,no statistical significance was observed for any association analyzed.Moreover,considering the age category between 31 and 59 years as the exposed group,the P value was 0.11 for the category 31 to 59 years and 0.32 for the category 60 years or older,showing that in both age categories there was no association between the pair of variables analyzed.Regarding chronic disease,the exposure group consisted of the participants without any comorbidity,so the P value of 0.07 for the category of those with at least one chronic disease showed no association between the two variables.CONCLUSION A temporal pattern of IgG response was not observed,but it is suggested that immunological memory is weak and there is no association between IgG production and age or chronic disease in mild COVID-19.
