Despite large improvements in the management of glucose levels and in the treatment of cardiovascular risk factors,the mortality rate in individuals with type 1 diabetes(T1D) is still high.Recently,Lind et al found th...Despite large improvements in the management of glucose levels and in the treatment of cardiovascular risk factors,the mortality rate in individuals with type 1 diabetes(T1D) is still high.Recently,Lind et al found that T1 D individuals with glycated hemoglobin levels of 6.9% or lower had a risk of death from any cause or from cardiovascular causes that is twice as high as the risk for matched controls.T1 D is a chronic disease with an early onset(e.g.,pediatric age) and thus in order to establish a clear correlation between death rate and the glycometabolic control,the whole history of glycemic control should be considered; particularly in the early years of diabetes.The switch from a normoto hyperglycemic milieu in an individual with T1 D in the pediatric age,represents a stressful event that may impact outcomes and death rate many years later.In this paper we will discuss the aforementioned issues,and offer our view on these findings,paying a particular attention to the several alterations occurring in the earliest phases of T1 D and to the many factors that may be associated with the chronic history of T1 D.This may help us to better understand the recently published death rate data and to develop future innovative and effective preventive strategies.展开更多
We study global asymptotic stability for an SIS epidemic model with maturation delay proposed by K. Cooke, P. van den Driessche and X. Zou, Interaction of maturation delay and nonlinear birth in population and epidemi...We study global asymptotic stability for an SIS epidemic model with maturation delay proposed by K. Cooke, P. van den Driessche and X. Zou, Interaction of maturation delay and nonlinear birth in population and epidemic models, J. Math. Biol. 39（4） （1999） 332-352. It is assumed that the population has a nonlinear birth term and disease causes death of infective individuals. By using a monotone iterative method, we establish sufficient conditions for the global stability of an endemic equilibrium when it exists dependently on the monotone property of the birth rate function. Based on the analysis, we further study the model with two specific birth rate functions BI（N） = be-aN and B3（N） = A/N ＋ c, where N denotes the total population. For each model, we obtain the disease induced death rate which guarantees the global stability of the endemic equilibrium and this gives a positive answer for an open problem by X. Q. Zhao and X. Zou, Threshold dynamics in a delayed SIS epidemic model, J. Math. Anal. Appl. 257（2） （2001） 282-291.展开更多
基金JDRF Career Development Award and an ADA Mentor-based Fellowship grantThe Harvard Stem Cell Institute grant("Diabetes Program"DP-0123-12-00)Italian Ministry of Health grant RF-2010-2303119 and RF-2010-2314794(all to Fiorina P)
文摘Despite large improvements in the management of glucose levels and in the treatment of cardiovascular risk factors,the mortality rate in individuals with type 1 diabetes(T1D) is still high.Recently,Lind et al found that T1 D individuals with glycated hemoglobin levels of 6.9% or lower had a risk of death from any cause or from cardiovascular causes that is twice as high as the risk for matched controls.T1 D is a chronic disease with an early onset(e.g.,pediatric age) and thus in order to establish a clear correlation between death rate and the glycometabolic control,the whole history of glycemic control should be considered; particularly in the early years of diabetes.The switch from a normoto hyperglycemic milieu in an individual with T1 D in the pediatric age,represents a stressful event that may impact outcomes and death rate many years later.In this paper we will discuss the aforementioned issues,and offer our view on these findings,paying a particular attention to the several alterations occurring in the earliest phases of T1 D and to the many factors that may be associated with the chronic history of T1 D.This may help us to better understand the recently published death rate data and to develop future innovative and effective preventive strategies.
文摘We study global asymptotic stability for an SIS epidemic model with maturation delay proposed by K. Cooke, P. van den Driessche and X. Zou, Interaction of maturation delay and nonlinear birth in population and epidemic models, J. Math. Biol. 39（4） （1999） 332-352. It is assumed that the population has a nonlinear birth term and disease causes death of infective individuals. By using a monotone iterative method, we establish sufficient conditions for the global stability of an endemic equilibrium when it exists dependently on the monotone property of the birth rate function. Based on the analysis, we further study the model with two specific birth rate functions BI（N） = be-aN and B3（N） = A/N ＋ c, where N denotes the total population. For each model, we obtain the disease induced death rate which guarantees the global stability of the endemic equilibrium and this gives a positive answer for an open problem by X. Q. Zhao and X. Zou, Threshold dynamics in a delayed SIS epidemic model, J. Math. Anal. Appl. 257（2） （2001） 282-291.
