Amino Acid Availability Regulates the Effect of Hyperinsulinemia on Skin Protein Metabolism in Pigs.

The effects of amino acid supply and insulin infusion on skin protein kinetics (fractional synthesis rate (FSR), fractional breakdown rate (FBR), and net balance (NB)) in pigs were investigated. Four-month-old pigs were divided into four groups as follows: control, insulin (INS), amino acid (AA), and INS + AA groups based on the nutritional and hormonal conditions. l-[ring-(13)C6]Phenylalanine was infused.

Triglycerides produced in the livers of fasting rabbits are predominantly stored as opposed to secreted into the plasma.

Objective: The liver plays a central role in regulating fat metabolism; however, it is not clear how the liver distributes the synthesized triglycerides (TGs) to storage and to the plasma.

Materials And Methods: We have measured the relative distribution of TGs produced in the liver to storage and the plasma by means of U-(13)C(16)-palmitate infusion in anesthetized rabbits after an overnight fast.

Results: The fractional synthesis rates of TGs stored in the liver and secreted into the plasma were not significantly different (stored vs.

Comparison of bolus injection and constant infusion methods for measuring muscle protein fractional synthesis rate in humans.

Background: The use of stable isotope tracer techniques to measure muscle protein fractional synthesis rate (FSR) has been well established and widely used. The most common method that has been utilized so far is a primed constant infusion (CI) method, which requires 3-4 h of tracer infusion. However, recently our group has developed a bolus injection (BI) method, which requires an injection of bolus of tracer and can be completed within 1 h.

A novel stable isotope tracer method to measure muscle protein fractional breakdown rate during a physiological non-steady-state condition.

The measurement of the fractional breakdown rate (FBR) of muscle proteins during physiological non-steady state of amino acids (AAs) presents some challenges. Therefore, the goal of the present experiment was to modify the bolus stable isotope tracer injection approach to determine both fractional synthesis rate (FSR) and FBR of leg muscle protein during a physiological non-steady state of AAs. The approach uses the traditional precursor-product principle but is modified with the assumption that inward transport of AAs is proportional to their plasma concentrations.

Adult patients are more catabolic than children during acute phase after burn injury: a retrospective analysis on muscle protein kinetics.

Purpose: This study was performed to determine if there is an age-related specificity in the response of muscle protein metabolism to severe burn injury during acute hospitalization. This is a retrospective analysis of previously published data.

Methods: Nineteen adult and 58 pediatric burn-injured patients (age 43.

Long-term oxandrolone treatment increases muscle protein net deposition via improving amino acid utilization in pediatric patients 6 months after burn injury.

Background: We recently showed that mechanisms of protein turnover in skeletal muscle are unresponsive to amino acid (AA) infusion in severely burned pediatric patients at 6 months postinjury. In the current study, we evaluated whether oxandrolone treatment affects mechanisms of protein turnover in skeletal muscle and whole-body protein breakdown in pediatric burn patients 6 months postinjury.

Methods: At the time of admission, patients were randomized to control or oxandrolone treatments.

Enternal [corrected] arginine supplementation stimulates DNA synthesis in skin donor wound.

Background & Aims: Arginine infusion has been demonstrated to increase wound protein deposition; however, the effects of its enteral supplementation on wound cell proliferation have not been studied.

Methods: Skin donor wound was created on the back of rabbits. The rabbits were randomly assigned to receive a control enteral diet, or the control enteral diet with supplemental arginine.

Skeletal muscle is anabolically unresponsive to an amino acid infusion in pediatric burn patients 6 months postinjury.

Objective: To evaluate leg muscle, whole-body muscle, and whole-body nonmuscle protein response to anabolic signaling of amino acids in pediatric burn patients at 6 months after injury.

Background: Burn injury is associated with a catabolic state persisting years after the injury. The tissue response to nutritional signaling (eg, amino acids) plays a critical role in tissue protein net balance via coordination of protein synthesis and breakdown mechanisms.

Intensive insulin treatment increases donor site wound protein synthesis in burn patients.

Background: In the treatment of burns, patients' own skin is the preferred material to cover burn wounds, resulting in the need to create a donor site wound. Enhancement of healing of the donor site wound would be beneficial in burn patients. Insulin, an anabolic agent, is used routinely to treat hyperglycemia after injury.

Temperature responses in severely burned children during exercise in a hot environment.

The authors have previously described thermoregulatory responses of severely burned children during submaximal exercise in a thermoneutral environment. However, the thermoregulatory response of burned children to exercise in the heat is not well understood and could have important safety implications for rehabilitation. Children (n = 10) with >40% TBSA burns and nonburned children (n = 10) performed a 30-minute bout of treadmill exercise at 75% of their peak aerobic power in a heated environment.

Donor site wound protein synthesis correlates with length of acute hospitalization in severely burned children.

Autografting of burn wounds results in generation of donor site wounds. Here we measured donor site wound protein fractional synthesis rate (FSR) in a burn pediatric population and showed that FSR increases over time postsurgery and correlates with the length of hospital stay (LOS) normalized for total body surface area (TBSA) burn size. 3.

Intensive insulin therapy improves insulin sensitivity and mitochondrial function in severely burned children.

Objective: To institute intensive insulin therapy protocol in an acute pediatric burn unit and study the mechanisms underlying its benefits.

Design: Prospective, randomized study.

Setting: An acute pediatric burn unit in a tertiary teaching hospital.

Whole body protein kinetics measured with a non-invasive method in severely burned children.

Unlabelled: Persistent and extensive skeletal muscle catabolism is characteristic of severe burns. Whole body protein metabolism, an important component of this process, has not been measured in burned children during the long-term convalescent period. The aim of this study was to measure whole body protein turnover in burned children at discharge (95% healed) and in healthy controls by a non-invasive stable isotope method.

Beneficial effects of insulin on cell proliferation and protein metabolism in skin donor site wound.

Background: Insulin has been demonstrated to accelerate skin wound healing; however, its effects on wound metabolism have not been adequately studied.

Materials And Methods: Adult rabbits were prepared by creation of skin donor site wound on the back, catheterization of the carotid artery and jugular vein, and placement of a nasogastric feeding tube under general anesthesia. The rabbits were given total enteral nutrition thereafter.

Enhanced albumin synthesis in severely burned adults.

Albumin plays an important role in maintaining physiological homeostasis. Although decreased albumin concentration has been well described as an acute-phase response following injury, it is unclear whether the decrease is due to compromised synthesis of albumin, dilution, or imbalance between synthesis and breakdown rates, particularly after injury. We investigated changes in albumin synthesis in severely burned patients using stable isotope infusion techniques.

Hypertrophic versus non hypertrophic scars compared by immunohistochemistry and laser confocal microscopy: type I and III collagens.

Although dermal collagens appear increased in hypertrophic scars, this has not been tested in tissue samples using objective methods. We compared the expression of types I and III collagen in hypertrophic and non hypertrophic scars at 6-12 and 18-24 months after burn using a quantitative method. Among 17 patients with extensive burns, 3 patients had acute scars, 8 had hypertrophic or non hypertrophic scars at 6-12 months after burn and 6 had hypertrophic or non hypertrophic scars at 18-24 months after burn.

Crew resource management improved perception of patient safety in the operating room.

To improve safety in the operating theater, a company of aviation pilots was employed to guide implementation of preprocedural briefings. A 5-point Likert scale survey that assessed the attitudes of operating room personnel toward patient safety was distributed before and 6 months following implementation of the briefings. Using Mann-Whitney analysis, the survey showed a significant (P < .

The leading causes of death after burn injury in a single pediatric burn center.

Introduction: Severe thermal injury is characterized by profound morbidity and mortality. Advances in burn and critical care, including early excision and grafting, aggressive resuscitation and advances in antimicrobial therapy have made substantial contributions to decrease morbidity and mortality. Despite these advances, death still occurs.

Measurement of body composition in burned children: is there a gold standard?

Background: Maintaining lean body mass (LBM) after a severe burn is an essential goal of modern burn treatment. An accurate determination of LBM is necessary for short- and long-term therapeutic decisions. The aim of this study was to compare 2 measurement methods for body composition, whole-body potassium counting (K count) and dual x-ray absorptiometry (DEXA), in a large prospective clinical trial in severely burned pediatric patients.

Randomized controlled trial to determine the efficacy of long-term growth hormone treatment in severely burned children.

Background: Recovery from a massive burn is characterized by catabolic and hypermetabolic responses that persist up to 2 years and impair rehabilitation and reintegration. The objective of this study was to determine the effects of long-term treatment with recombinant human growth hormone (rhGH) on growth, hypermetabolism, body composition, bone metabolism, cardiac work, and scarring in a large prospective randomized single-center controlled clinical trial in pediatric patients with massive burns.

Patients And Methods: A total of 205 pediatric patients with massive burns over 40% total body surface area were prospectively enrolled between 1998 and 2007 (clinicaltrials.

The synthetic rate of muscle triglyceride but not phospholipid is increased in obese rabbits.

Fat is a major energy source for skeletal muscle, and disruption of normal trafficking of fatty acids in muscle is linked to insulin resistance. We quantified muscle triglyceride (TG) and phospholipid (PL) synthesis in lean and obese rabbits by means of l-[U-(13)C(16)]palmitate infusion. Intramyocellular palmitoyl-coenzyme A was used as the precursor for rates of TG and PL synthesis, which were compared with the rates calculated using plasma nonesterified palmitate as the precursor.

Measurement of protein fractional synthesis and breakdown rates in the skin of rabbits using a subflooding dose method.

The flooding dose method continues to be useful in measuring protein fractional synthetic rate (FSR) in a tissue. However, flooding of free amino acid pools eliminates enrichment difference between plasma and tissue free amino acid pools, which makes it impossible to concomitantly measure protein fractional breakdown rate (FBR). We hypothesized that a subflooding dose of an amino acid reduces the enrichment difference between plasma and tissue free amino acid pool to a minimal measurable level, thus allowing concomitant measurement of protein FSR and FBR.

Acute propranolol infusion stimulates protein synthesis in rabbit skin wound.

Background: Propranolol administration has been demonstrated to improve cardiac work, decrease energy expenditure, and attenuate lipolysis in burned patients; however, its effect on wound healing has not been reported.

Methods: In rabbits, a partial-thickness skin donor site wound was created on the back, and catheters were placed in the carotid artery and jugular vein. A nasogastric feeding tube was placed for enteral feeding.