Purpose
The debate about the impact of intensified hyperglycemia treatment is still ranging. The main objective was to assess whether intensive glycemic control in hospitalized diabetic patients ...undergoing a liver transplant is associated with a lower rate of graft rejection at 3 months and at 5 years post-transplant.
Methods
Cross-sectional study comparing a cohort of patients undergoing liver transplant in 2010 and 2011, in whom an intensive insulin protocol was applied, with a retrospective group of patients undergoing a liver transplant in 2005 and 2006, in whom a conventional insulin protocol was applied. Both diabetics and non-diabetics were compared. As intensive insulin therapy is applied mainly in diabetic patients, it is expected that, when comparing both periods, the treatment would only benefit those patients.
Results
The logistic regression model showed a statistically significant interaction between the treatment group and the presence of diabetes for the rejection rate 3 months and 5 years post-transplant. At both time points, the intensive insulin treatment group had lower rejection rates in the case of diabetic patients, which did not occur in non-diabetic patients.
Conclusions
Our study shows a decrease in the rate of liver graft rejection in diabetic patients undergoing intensive insulin treatment.
We approximate the solution of a system of nonlinear mixed Fredholm–Volterra integro-differential equations of the second kind, using fixed point techniques and Schauder bases in certain Banach ...spaces. The convergence and error are studied. Several numerical examples are given, and the obtained numerical approximations are compared with the corresponding exact solutions.
Operating satellites in Very Low Earth Orbit (VLEO) benefit the already expanding New Space industry in applications including Earth Observation and beyond. However, long-term operations at such low ...altitudes require propulsion systems to compensate for the large aerodynamic drag forces. When using conventional propulsion systems, the amount of storable propellant limits the maximum mission lifetime. The latter can be avoided by employing Atmosphere-Breathing Electric Propulsion (ABEP) system, which collects the residual atmospheric particles and uses them as propellant for an electric thruster. Thus, the requirement of on-board propellant storage can ideally be nullified. At the Institute of Space Systems (IRS) of the University of Stuttgart, an intake, and a RF Helicon-based Plasma Thruster (IPT) for ABEP system are developed within the Horizons 2020 funded DISCOVERER project. To assess possible future use cases, this paper proposes and analyzes several novel ABEP-based mission scenarios. Beginning with technology demonstration mission in VLEO, more complex mission scenarios are derived and discussed in detail. These include, amongst others, orbit maintenance around Mars as well as refuelling and space tug missions. The results show that the ABEP system is not only able to compensate drag for orbit maintenance but also capable of performing orbital maneuvers and collect propellant for applications such as Space Tug and Refuelling. Thus, showing a multitude of different future mission applications.
Natural history of recurrent hepatitis C Berenguer, Marina
Liver transplantation,
October 2002, 2002-Oct, 2002-10-00, 20021001, Letnik:
8, Številka:
10
Journal Article
Recenzirano
1. After liver transplantation for hepatitis C virus (HCV)-related cirrhosis, recurrence of infection is universal, with development of histological hepatitis in the majority of patients. 2. The ...natural history of recurrent hepatitis C is highly variable. Although 30% to 50% of patients develop posttransplantation viremia with minimal liver injury, 10% to 30% progress to cirrhosis after a median of 5 years. 3. Progression of hepatitis C is accelerated in immunocompromised liver transplant recipients compared with immunocompetent patients, both before and after the development of compensated cirrhosis. 4. HCV-related disease progression is faster in patients who underwent transplantation in recent years compared with those who underwent transplantation earlier. 5. HCV infection significantly impairs patient and allo-graft survival after liver transplantation. 6. Several variables, including donor age, degree of immunosuppression, viral load either pretransplantation or early posttransplantation, timing of recurrence, and early histological findings, are implicated in the outcome of hepatitis C posttransplantation. (Liver Transpl 2002;8:S14-S18.)
This article summarizes the current therapies, with particular emphasis on antiviral therapy. Because these alternatives have substantial limitations, pretransplant or early post-transplant ...recognition of patients with high risk of severe post-transplantation outcome is desirable to target these patients for intervention. Alternatively, the implementation of measures aimed at reducing or avoiding factors known to be associated with an aggressive recurrence is an additional strategy that needs to be explored.
Controversy exists about the usefulness of yearly protocol liver biopsies after liver transplantation, mainly among patients with normal transaminase levels. The aim of this study is to determine (1) ...the prevalence and cause of histological liver injury in transplant recipients with a minimum histological follow-up of 1 year (n = 254), and (2) the correlation between histological findings and transaminase values. The main indication for liver transplantation was viral-related cirrhosis (61%; 86% caused by hepatitis C virus HCV). Protocol liver biopsies were performed yearly for the first 5 years in HCV-infected transplant recipients and at 1 and 5 years in the remaining patients. Histological liver injury included several categories of liver damage (hepatitis, rejection, steatohepatitis, cholangitis, and Budd-Chiari–like lesions). Among biopsy specimens categorized as hepatitis, severe hepatitis was defined as the presence of stage 3 or greater fibrosis. The prevalence of liver injury increased significantly with time (42%
v 56% at 1 and 5 years, respectively;
P = .09) and was significantly greater in patients who underwent transplantation for HCV-related cirrhosis than in those who underwent transplantation for other reasons (
P = .0001). The most frequent category of liver injury was hepatitis (97% and 96% at 1 and 5 years, respectively). Although a proportion of patients with liver injury (12% to 29%) had normal transaminase values, this percentage was almost null in patients with severe hepatitis. Normal histological characteristics were found in the vast majority of non–HCV-infected transplant recipients with normal transaminase values. Given the high prevalence of abnormal histological findings, particularly the increase over time of those defined as severe, protocol liver biopsies are clearly justified in HCV-infected transplant recipients. Conversely, given the rarity of abnormal histological findings, protocol liver biopsies should be questioned in non–HCV-infected transplant recipients with normal transaminase values. (
Liver Transpl 2001;7:790-796.)
This paper consists of two parts. The first one deals with the generation of an iterative algorithm to obtain an approximate solution of a linear equation of the second kind in a Banach space. This ...generation is based on a perturbed version of the geometric series theorem which, in particular, allows us to find a family of unisolvent linear Fredholm integral equations of the second kind, even when the associated linear operator has norm greater than or equal to 1. When we consider Fredholm equations of this type and linear Volterra integral equations of second kind, the numerical schemes obtained when appropriate Schauder bases are also introduced in the spaces where the equations operate, enable us to approximate their respective solutions iteratively. The second part of this work focuses on the design of a numerical method for solving an inverse problem associated with a linear equation of the second kind in a Banach space, a method which we apply to problems of parameter estimation related to the two classes of integral equations mentioned above.
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