Burns Research Group

Lab head: Prof Peter Maitz
Location: ANZAC Research Institute (Concord Hospital)

Website: http://www.anzac.edu.au/

Macronutrients, metabolism and burn injury

Primary supervisor: Yiwei Wang

Project description

Background:

Severe burn injuries, which damage more than 20% total body surface area (TBSA), are the most traumatic and physically debilitating injuries affecting nearly every organ system, and lead to significant morbidity and mortality. Such severe burns are typically followed by a period of extreme stress, systemic inflammation and a hypermetabolic-catabolic state, within significantly increased metabolic rate of 40-80% above normal in the first few months after injury which remains raised for up to 1 year. The hypermetabolic-catabolic state also leads to abnormal metabolism of nutrients and increased energy requirements for burn patients. In the treatment of such burn injury, aggressive and early high energy enteral feeding is essential to mitigate the degree and extend of hypermetabolism and to improve outcomes in the burned patients. However, there is no current consensus on the ratio of macronutrients needed in nutritional interventions aimed at the treatment of severe burn injury. Reflecting this uncertainty, the macronutrient (protein, carbohydrate and fat) composition of enteral feeding diets varies considerably between burns units across the globe. Consistently 15-25% of calories are provided by protein (reflecting a high protein diet), but the amount of carbohydrate varies from 40-85% and the amount of fat from 3-40% of total energy and the appropriate composition of these two macronutrients is greatly debated.

 

Objective: The proposed study therefore plans to comprehensively investigate the optimal ratio of macronutrients: protein, carbohydrate and fat in improving outcome in severe burn injury. These translational studies will provide new knowledge to guide nutritional management in complex burn injury patients and provide experimental evidence for the development of a novel nutritional regime for treating severe burn injury and potentially also multi-trauma and patients with critically ill due to other pathologies.

 

The aim of this project is therefore to delineate in a logical, multi-step approach the mechanisms by which macronutrient composition influences the healing of burn wounds using an established severe burn injury mouse model.

 

Methodology:

1. Introduction to small animal handling, surgery and tissue collection (mouse anatomy, tissue processing).

2. Basic histological techniques: Cutting and handling paraffin sections (microtome use) basic histological staining methods.

3. Immunohistochemistry for detection of proliferative cells within tissue.

4. Molecular biology methods: mRNA extraction, cDNA conversion to generate templates for analysis of mRNA expression levels by real-time or RT-PCR based methods. Western blot or ELISA to determine the inflammatory mediator level in the wound tissue.

5. Introduction to metabolic cage system.

 

Reference:

[1] F.N. Williams, L.K. Branski, M.G. Jeschke, D.N. Herndon, What, how, and how much should patients with burns be fed?, Surgical Clinics of North America 91(3) (2011) 609-629.

[2] M.G. Jeschke, G.G. Gauglitz, G.A. Kulp, C.C. Finnerty, F.N. Williams, R. Kraft, O.E. Suman, R.P. Mlcak, D.N. Herndon, Long-term persistance of the pathophysiologic response to severe burn injury, PloS one 6(7) (2011) e21245.

[3] C. Porter, D.N. Herndon, E. Børsheim, N. Bhattarai, T. Chao, P.T. Reidy, B.B. Rasmussen, C.R. Andersen, O.E. Suman, L.S. Sidossis, Long-term skeletal muscle mitochondrial dysfunction is associated with hypermetabolism in severely burned children, Journal of Burn Care & Research 37(1) (2016) 53-63.

[4] D.W. Hart, S.E. Wolf, R. Mlcak, D.L. Chinkes, P.I. Ramzy, M.K. Obeng, A.A. Ferrando, r.R. WOlfe, D.N. Herndon, Persistence of muscle catabolism after severe burn, Surgery 128 (2000) 312-319.

[5] C.J. Wray, J.M.V. Mammen, P. Hasselgren, Catabolic response to stree and potential benefits of nutrition support, Nutrition support in specific surgical conditions 18 (2002) 971-977.

[6] B. Masters, F. Wood, Nutrition Support in Burns—Is there Consistency in Practice? Journal of Burn Care & Research 29(4) (2008) 561-571.


Discipline: Pathology
Co-supervisors: Peter Maitz
Keywords: Burns injuries, Nutrition, Burns and Reconstructive Surgery
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