Melatonin and organ transplantation: what is the relationship?

SUMMARY Melatonin has anti-inflammatory and antioxidant properties that can influence tissue growth and apoptosis. This aspect may influence the success of organ transplantation. OBJECTIVE To evaluate the relationship between melatonin and organ transplantation. METHODS A systematic review was performed in PubMed databases using the search terms: "melatonin physiology" or "melatonin therapy" and "transplant pharmacology" or "transplant physiology" or "transplant therapy" or "Transplant therapy". Experiments on the organs of the reproductive system were not included. After analysis, five articles were selected after reading the title and abstract of 50 manuscripts. The works were divided into two aspects: a) analysis of the influence of the organ transplantation procedure on melatonin production; b) action of melatonin on organ transplantation. RESULTS The cardiac transplantation surgical procedure, immunosuppression, and graft did not influence melatonin secretion in rodents, but there was a significant reduction of melatonin in the renal transplantation procedure in patients with renal insufficiency. Melatonin administration in experimental models decreased rejection and improved transplant success. CONCLUSION Studies show that melatonin can reduce organ and species dependence, and the use of melatonin decreases graft rejection.

RESUMO A melatonina tem propriedades anti-inflamatórias e antioxidantes que podem influenciar o crescimento e a apoptose dos tecidos. Esse aspecto pode influenciar o sucesso do transplante de órgãos. OBJETIVO Avaliar a relação entre a melatonina e o transplante de órgãos. MÉTODO A revisão sistemática foi realizada nas bases de dados do PubMed, usando os termos de pesquisa: "fisiologia da melatonina" ou "terapêutica da melatonina" e "farmacologia do transplante" ou "fisiologia do transplante" ou "terapêutica do transplante" ou "terapia do transplante". Não foram incluídos os experimentos sobre os órgãos do sistema reprodutivo. Após análise, cinco artigos foram selecionados após a leitura do título e do resumo de 50 manuscritos. Os trabalhos foram divididos em duas vertentes: a) análise da influência do procedimento de transplante de órgão na produção de melatonina; b) ação da melatonina sobre o transplante de órgãos. RESULTADOS O procedimento cirúrgico do transplante cardíaco, a imunossupressão e o enxerto não influenciaram a secreção de melatonina em roedores, mas houve redução significante da melatonina nos casos do procedimento de transplante renal em pacientes com insuficiência renal. A ministração de melatonina em modelos experimentais diminuiu a rejeição e melhorou o sucesso de transplante. CONCLUSÃO Os estudos mostram que a melatonina pode reduzir a dependência da espécie e do órgão e que o emprego da melatonina diminui a rejeição do órgão.

Factors associated with the prescription of vaginal pessaries for pelvic organ prolapse

OBJECTIVE: To identify the factors associated with the prescription of vaginal pessaries (VPs) as a conservative treatment for pelvic organ prolapse (POP). METHODS: A cross-sectional study was performed during two annual urogynecology and general obstetrics and gynecology meetings in 2017 (São Paulo, SP, Brazil). A 19-item deidentified questionnaire regarding experiences and practices in prescribing VPs for POP patients was distributed among gynecologists. Our primary outcome was the frequency of prescribing VPs as a conservative treatment for POP. The reasons for prescribing or not prescribing VPs were also investigated. Univariate and multivariate analyses with crude and adjusted odds ratios (ORs) were performed for variables associated with the prescription of pessaries. RESULTS: Three hundred forty completed surveys were analyzed. Half of the respondents (53.53%) were between 30-49 years old; most of them were female (73.53%), were from the Southeast Region (64.12%), were trained in obstetrics and gynecology (80.24%) or urogynecology (61.18%) and worked in private offices (63.42%). More than one-third (36.48%) attended four or more POP cases/week, and 97.65% (n=332) had heard or knew about VPs for POP; however, only 47.06% (n=160) prescribed or offered this treatment to patients. According to the multivariate analysis, physicians aged 18-35 years (OR=1.97[1.00-3.91]; p=0.04), those who participated in a previous urogynecology fellowship (OR=2.34[1.34-4.09]; p<0.01), those with relatively high volumes of POP cases (4 or +) (OR=2.23[1.21-4.47]; p=0.01) and those with PhD degrees (OR=2.75[1.01-7.54]; p=0.05) prescribed more pessaries. CONCLUSIONS: Most gynecologists did not prescribe VPs. Younger physician age, participation in a previous urogynecology fellowship, a PhD degree, and a relatively high volume of POP cases were associated with increased VP prescription rates.