RESUMO
The evolution of Crassulacean acid metabolism (CAM) by plants has been one of the most successful strategies in response to aridity. On the onset of climate change, expanding the use of water efficient crops and engineering higher water use efficiency into C3 and C4 crops constitute a plausible solution for the problems of agriculture in hotter and drier environments. A firm understanding of CAM is thus crucial for the development of agricultural responses to climate change. Computational models on CAM can contribute significantly to this understanding. Two types of models have been used so far. Early CAM models based on ordinary differential equations (ODE) reproduced the typical diel CAM features with a minimal set of components and investigated endogenous day/night rhythmicity. This line of research brought to light the preponderant role of vacuolar malate accumulation in diel rhythms. A second wave of CAM models used flux balance analysis (FBA) to better understand the role of CO2 uptake in flux distribution. They showed that flux distributions resembling CAM metabolism emerge upon constraining CO2 uptake by the system. We discuss the evolutionary implications of this and also how CAM components from unrelated pathways could have integrated along evolution.
RESUMO
BACKGROUND: Cancer is currently among the three leading causes of death after solid organ transplantation and its incidence is increasing. Non-melanoma skin cancer - squamous cell carcinoma and basal cell carcinoma - is the most common malignancy found in kidney transplant recipients (KTRs). The incidence of non-melanoma skin cancer in KTRs has not been extensively studied in Portugal. OBJECTIVES: To determine the incidence of non-melanoma skin cancer in KTRs from the largest Portuguese kidney transplant unit; and to study risk factors for non-melanoma skin cancer. METHODS: Retrospective analysis of clinical records of KTRs referred for the first time for a dermatology consultation between 2004 and 2013. A case-control study was performed on KTRs with and without non-melanoma skin cancer. RESULTS: We included 288 KTRs with a median age at transplantation of 47 years, a male gender predominance (66%) and a median transplant duration of 3.67 years. One fourth (n=71) of KTRs developed 131 non-melanoma skin cancers, including 69 (53%) squamous cell carcinomas and 62 (47%) basal cell carcinomas (ratio squamous cell carcinoma: basal cell carcinoma 1.11), with a mean of 1.85 neoplasms per patient. Forty percent of invasive squamous cell carcinomas involved at least two clinical or histological high-risk features. The following factors were associated with a higher risk of non-melanoma skin cancer: an older age at transplantation and at the first consultation, a longer transplant duration and the presence of actinic keratosis. KTRs treated with azathioprine were 2.85 times more likely to develop non-melanoma skin cancer (p=0.01). CONCLUSION: Non-melanoma skin cancer was a common reason for dermatology consultation in Portuguese KTRs. It is imperative for KTRs to have access to specialized dermatology consultation for early referral and treatment of skin malignancies.
Assuntos
Carcinoma Basocelular/epidemiologia , Carcinoma de Células Escamosas/epidemiologia , Transplante de Rim/efeitos adversos , Neoplasias Cutâneas/epidemiologia , Transplantados , Adolescente , Adulto , Fatores Etários , Idoso , Carcinoma Basocelular/etiologia , Carcinoma de Células Escamosas/etiologia , Criança , Feminino , Humanos , Imunossupressores/efeitos adversos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Neoplasias Cutâneas/etiologia , Fatores de Tempo , Adulto JovemRESUMO
Abstract: Background: Cancer is currently among the three leading causes of death after solid organ transplantation and its incidence is increasing. Non-melanoma skin cancer - squamous cell carcinoma and basal cell carcinoma - is the most common malignancy found in kidney transplant recipients (KTRs). The incidence of non-melanoma skin cancer in KTRs has not been extensively studied in Portugal. Objectives: To determine the incidence of non-melanoma skin cancer in KTRs from the largest Portuguese kidney transplant unit; and to study risk factors for non-melanoma skin cancer. Methods: Retrospective analysis of clinical records of KTRs referred for the first time for a dermatology consultation between 2004 and 2013. A case-control study was performed on KTRs with and without non-melanoma skin cancer. Results: We included 288 KTRs with a median age at transplantation of 47 years, a male gender predominance (66%) and a median transplant duration of 3.67 years. One fourth (n=71) of KTRs developed 131 non-melanoma skin cancers, including 69 (53%) squamous cell carcinomas and 62 (47%) basal cell carcinomas (ratio squamous cell carcinoma: basal cell carcinoma 1.11), with a mean of 1.85 neoplasms per patient. Forty percent of invasive squamous cell carcinomas involved at least two clinical or histological high-risk features. The following factors were associated with a higher risk of non-melanoma skin cancer: an older age at transplantation and at the first consultation, a longer transplant duration and the presence of actinic keratosis. KTRs treated with azathioprine were 2.85 times more likely to develop non-melanoma skin cancer (p=0.01). Conclusion: Non-melanoma skin cancer was a common reason for dermatology consultation in Portuguese KTRs. It is imperative for KTRs to have access to specialized dermatology consultation for early referral and treatment of skin malignancies.
Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Neoplasias Cutâneas/epidemiologia , Carcinoma Basocelular/epidemiologia , Carcinoma de Células Escamosas/epidemiologia , Transplante de Rim/efeitos adversos , Transplantados , Portugal/epidemiologia , Neoplasias Cutâneas/etiologia , Carcinoma Basocelular/etiologia , Carcinoma de Células Escamosas/etiologia , Incidência , Estudos Retrospectivos , Fatores de Risco , Fatores Etários , Estimativa de Kaplan-Meier , Adulto Jovem , Imunossupressores/efeitos adversosAssuntos
Humanos , Masculino , Feminino , Adulto , Ácido Úrico/urina , Cálcio , Cálculos Renais/urina , Citratos , Doenças Inflamatórias Intestinais/urina , Hiperoxalúria , Magnésio/urinaRESUMO
O refluxo vesicoureteral primário é uma condição freqüentemente ameaçadora ao parênquima renal. Esta doença severa pode levar a uma displasia e cicatrização renal. Quando revelada por infecção aguda do trato urinário, o dano renal em muitos casos quase sempre ocorre, sendo a intervenção clínica ou cirúrgica tardia. Objetivamos, através do enfoque deste assunto, alertar para o diagnóstico precoce, screening de populações de alto risco e prevenção de infecções, juntamente com melhor manejo de disfunção vesical, no intuito de reduzir a incidência de dano renal devido a refluxo vesicoureteral primário