Zonation of hepatic fatty acid metabolism - The diversity of its regulation and the benefit of modeling.

A pronounced heterogeneity between hepatocytes in subcellular structure and enzyme activities was discovered more than 50years ago and initiated the idea of metabolic zonation. In the last decades zonation patterns of liver metabolism were extensively investigated for carbohydrate, nitrogen and lipid metabolism. The present review focuses on zonation patterns of the latter. We review recent findings regarding the zonation of fatty acid uptake and oxidation, ketogenesis, triglyceride synthesis and secretion, de novo lipogenesis, as well as bile acid and cholesterol metabolism. In doing so, we expose knowledge gaps and discuss contradictory experimental results, for example on the zonation pattern of fatty acid oxidation and de novo lipogenesis. Thus, possible rewarding directions of further research are identified. Furthermore, recent findings about the regulation of metabolic zonation are summarized, especially regarding the role of hormones, nerve innervation, morphogens, gender differences and the influence of the circadian clock. In the last part of the review, a short collection of models considering hepatic lipid metabolism is provided. We conclude that modeling, despite its proven benefit for understanding of hepatic carbohydrate and ammonia metabolisms, has so far been largely disregarded in the study of lipid metabolism; therefore some possible fields of modeling interest are presented.

Proteomics applied to transfusion plasma: the beginning of the story.

'Safe blood' is and has always been the major concern in transfusion medicine. Plasma can undergo virus inactivation treatments based on physicochemical, photochemical or thermal methodologies for pathogen inactivation. The validation of these treatments is essentially based on clottability assays and clotting factors' titration; however, their impact on plasma proteins at the molecular level has not yet been evaluated. Proteomics appears as particularly adapted to identify, to localize and, consequently, to correlate these modifications to the biological activity change. At the crossroads of biology and analytical sciences, proteomics is the large-scale study of proteins in tissues, physiological fluids or cells at a given moment and in a precise environment. The proteomic strategy is based on a set of methodologies involving separative techniques like mono- and bidimensional gel electrophoresis and chromatography, analytical techniques, especially mass spectrometry, and bioinformatics. Even if plasma has been extensively studied since the very beginning of proteomics, its application to transfusion medicine has just begun. In the first part of this review, we present the principles of proteomics analysis. Then, we propose a state of the art of proteomics applied to plasma analysis. Finally, the use of proteomics for the evaluation of the impact of storage conditions and pathogen inactivation treatments applied to transfusion plasma and for the evaluation of therapeutic protein fractionated is discussed.

Medical express ... physician practice management.

There's a hot new acronym in town, and investors from Wall Street to your street are paying attention. Physician management companies--better known as PMCs--are the newest force in the health care market. But is this bigger-is-better approach alienating more people than it's attracting? And how long before the boom goes burst?

As Catholic hospitals begin to merge with for-profit health systems, leaders of both are wondering for whom the church bell tolls.

As Catholic hospitals begin to work with for-profit health systems, leaders on both sides are asking themselves whether this is a match made in heaven. (It was St. Luke, after all, who first said that you can't serve both God and money). With such contrasting missions, can these distinctive entities mesh and still stay true to their calling?

Riding the express. Is your subacute strategy on track?

For many health care providers, it's time to catch the bullet train called subacute care, an area of health care that's booming and offers new opportunity. But riding the rails of this new mode of transport isn't as easy as it seems. In fact, it can be downright tricky. That's why experts are warning hospital executives, in particular, to know beforehand exactly what they're getting into.

Capitation revisited: integrated systems learn how to manage care and risk.

Caught in the middle of HMO price wars, integrated delivery systems are tightening their belts and demanding a greater share of what they save from delivering good outcomes more efficiently. Quality isn't endangered yet, leaders agree, but could be unless employers start to incorporate outcomes measures into their choice of health plans.

A new rhythm for the Blues.

If 1994 was the year the nation's Blue Cross and Blue Shield plans surpassed their managed care competitors in enrollment, 1995 is shaping up to be the year the Blues lead the stampede to form integrated delivery systems. Plus, a look at the new BC/BS chief, Patrick Hays.

Healthier times at Ridgemont High.

In a growing number of communities around the nation, school-based health clinics are providing a place where kids and teens can turn for everything from an annual physical examination to confidential alcohol and substance abuse counseling to teen parenting classes.