Sepsis Abstracts 1

©

Antioxidant supplementation in sepsis and systemic inflammatory response syndrome
            (Berger and Chiolero, 2007) Download
OBJECTIVE: Summarize the current knowledge about oxidative stress-related organ dysfunction in inflammatory and septic conditions, and its potential prevention and treatment by antioxidants in critically ill patients, focusing on naturally occurring antioxidants and clinical trials. STUDY SELECTION: PubMed, MEDLINE, and personal database search. SYNTHESIS: Plasma concentrations of antioxidant micronutrients are depressed during critical illness and especially during sepsis. The causes of these low levels include losses with biological fluids, low intakes, dilution by resuscitation fluids, as well as systemic inflammatory response syndrome-mediated redistribution of micronutrients from plasma to tissues. Numerous clinical trials have been conducted, many of which have shown beneficial effects of supplementation. Interestingly, among the candidates, glutamine, glutathione, and selenium are linked with the potent glutathione peroxidase enzyme family at some stage of their synthesis and metabolism. CONCLUSIONS: Three antioxidant nutrients have demonstrated clinical benefits and reached level A evidence: a) selenium improves clinical outcome (infections, organ failure); b) glutamine reduces infectious complication in large-sized trials; and c) the association of eicosapentaenoic acid and micronutrients has significant anti-inflammatory effects. Other antioxidants are still on the clinical benchmark level, awaiting well-designed clinical trials.

Glutathione metabolism in sepsis
            (Biolo et al., 2007) Download
Sepsis is characterized by severe redox imbalance. Glutathione plays a major role in cellular defenses against oxidative and nitrosative stress. There is limited information on the response of glutathione synthesis in human sepsis. This review proposes a critical analysis of available data on potential factors affecting glutathione synthesis in sepsis. Glutathione is synthesized from its constituent amino acids--glutamate, cysteine, and glycine. Cysteine availability and the activity of the enzyme glutamate cysteine ligase are rate-limiting for glutathione synthesis. Glutathione synthetic capacity is increased in liver and other tissues during the acute phase of experimental sepsis. Potential mechanisms for glutamate cysteine ligase activation in sepsis involve a decreased ratio of reduced/oxidized glutathione as well as the effects of reactive oxygen species, nitric oxide species, proinflammatory cytokines, heat shock proteins, and physical inactivity. Glutathione synthesis can be impaired by cysteine depletion, protein-energy malnutrition, hyperglycemia, glucocorticoid at pharmacologic doses, and decreased secretion of anterior pituitary hormones (growth hormones, thyrotropin, gonadotropins), as often observed in prolonged critical illness.

Vitamin D Insufficiency and Sepsis Severity in Emergency Department Patients With Suspected Infection
            (Ginde et al., 2011) Download
ACADEMIC EMERGENCY MEDICINE 2011; 18:1-4 (c) 2011 by the Society for Academic Emergency Medicine ABSTRACT: Objectives: Vitamin D is increasingly recognized as an important mediator of immune function and may have a preventive role in the pathogenesis of sepsis. We sought to evaluate the association between vitamin D status and sepsis severity and hypothesized that vitamin D insufficiency would be associated with increased sepsis severity. Methods: This was a pilot study of emergency department (ED) patients age >/=18 years evaluated for suspected infection at an urban, teaching hospital. The authors measured illness severity using the following assessments at baseline and 24 hours: 1) severe sepsis, defined as suspected infection plus two or more elements of systemic inflammatory response syndrome criteria and acute dysfunction of one or more organ systems; 2) Acute Physiology Age Chronic Health Evaluation (APACHE) II scores; and 3) Sepsis-related Organ Failure Assessment (SOFA) scores. Vitamin D insufficiency was defined as baseline serum 25-hydroxyvitamin D (25OHD) levels <75 nmol/L. Results: Eighty-one patients were enrolled, with a median age of 62 years (interquartile range [IQR] = 48-76 years), 47% were female, and 77% were white. At baseline, 64 (79%) had 25OHD levels of <75 nmol/L, and 43 (53%) had severe sepsis. At 24 hours, 48 (59%) had severe sepsis. Patients with baseline 25OHD levels of <75 nmol/L, compared to patients with 25OHD levels of >/=75 nmol/L, were more likely to have severe sepsis (61% vs. 24%; p = 0.006) and SOFA scores >/=2 (44% vs. 18%; p = 0.049). Additionally, at 24 hours, those with 25OHD levels of <75 nmol/L were more likely to have severe sepsis (67% vs. 29%; p = 0.005), dysfunction of two or more organ systems (50% vs. 18%; p = 0.02), APACHE II score of >/=25 (19% vs. 0%; p = 0.06), and SOFA scores of >/=2 (63% vs. 29%; p = 0.02). Additionally, all four patients who died during the index hospitalization had 25OHD levels of <75 nmol/L. Conclusions: Vitamin D insufficiency was associated with higher sepsis severity in ED patients hospitalized for suspected infection. Larger observational studies, mechanistic studies, and ultimately randomized controlled trials are needed to determine causation and to evaluate if vitamin D supplementation can reduce the risk of sepsis as a preventive or therapeutic strategy.


Arginine, citrulline and nitric oxide metabolism in sepsis
            (Kao et al., 2009) Download
Arginine has vasodilatory effects, via its conversion by NO synthase into NO, and immunomodulatory actions which play important roles in sepsis. Protein breakdown affects arginine availability and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore affect NO synthesis in patients with sepsis. The objective of the present study was to investigate whole-body in vivo arginine and citrulline metabolism and NO synthesis rates, and their relationship to protein breakdown in patients with sepsis or septic shock and in healthy volunteers. Endogenous leucine flux, an index of whole-body protein breakdown rate, was measured in 13 critically ill patients with sepsis or septic shock and seven healthy controls using an intravenous infusion of [1-13C]leucine. Arginine flux, citrulline flux and the rate of conversion of arginine into citrulline (an index of NO synthesis) were measured with intravenous infusions of [15N2]guanidino-arginine and [5,5-2H2]citrulline. Plasma concentrations of nitrite plus nitrate, arginine, citrulline and asymmetric dimethylarginine were measured. Compared with controls, patients had a higher leucine flux and higher NO metabolites, but arginine flux, plasma asymmetric dimethylarginine concentration and the rate of NO synthesis were not different. Citrulline flux and plasma arginine and citrulline were lower in patients than in controls. Arginine production was positively correlated with the protein breakdown rate. Whole-body arginine production and NO synthesis were similar in patients with sepsis and septic shock and healthy controls. Despite increased proteolysis in sepsis, there is a decreased arginine plasma concentration, suggesting inadequate de novo synthesis secondary to decreased citrulline production.

Niacin as a novel therapy for septic shock?
            (Kapoor and Thiemermann, 2011) Download

Niacin attenuates lung inflammation and improves survival during sepsis by downregulating the nuclear factor-kappaB pathway
            (Kwon et al., 2011) Download
OBJECTIVES: To examine whether niacin attenuates lung inflammation and improves survival during sepsis and to determine whether the beneficial effects of niacin are associated with downregulation of the nuclear factor (NF)-kappaB pathway. DESIGN: Prospective laboratory study. SETTING: University laboratory. SUBJECTS: Male Sprague-Dawley rats (n = 119). INTERVENTIONS: To induce endotoxemia in rats, lipopolysaccharide (Escherichia coli, O26:B6) at a dosage of 10 mg/kg was injected into a tail vein and 10 mins later, vehicle, a low dose of niacin (360 mg/kg), or a high dose of niacin (1180 mg/kg) was administered once through an orogastric tube, respectively. MEASUREMENTS AND MAIN RESULTS: We observed the survival of the subjects for 72 hrs. At 6 hrs postlipopolysaccharide, we euthanized animals and measured cytoplasmic phosphorylated inhibitor kappaB-alpha and inhibitor kappaB-alpha expressions, nuclear NF-kappaB p65 expression, NF-kappaB p65 DNA-binding activity, tumor necrosis factor-alpha, and interleukin-6 gene expressions and histologic damages in lung tissues. We also measured nicotinamide adenine dinucleotide, reduced nicotinamide adenine dinucleotide phosphate, reduced glutathione, and malondialdehyde levels in lung tissues. High dose of niacin suppressed NF-kappaB activation and proinflammatory cytokine gene expressions in lung tissues, reduced histologic lung damages, and improved survival in endotoxemic rats. Furthermore, it increased nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate, and glutathione levels and decreased malondialdehyde level in lung tissues. CONCLUSIONS: High dose of niacin attenuated lung inflammation, reduced histologic lung damages, and improved survival during sepsis in rats. These therapeutic benefits were associated with downregulation of the NF-kappaB pathway.

Exogenous arginine in sepsis
            (Luiking and Deutz, 2007) Download
Sepsis is a severe condition in critically ill patients and is considered an arginine deficiency state. The rationale for arginine deficiency in sepsis is mainly based on the reduced arginine levels in sepsis that are associated with the specific changes in arginine metabolism related to endothelial dysfunction, severe catabolism, and worse outcome. Exogenous arginine supplementation in sepsis shows controversial results with only limited data in humans and variable results in animal models of sepsis. Since in these studies the severity of sepsis varies but also the route, timing, and dose of arginine, it is difficult to draw a definitive conclusion for sepsis in general without considering the influence of these factors. Enhanced nitric oxide production in sepsis is related to suggested detrimental effects on hemodynamic instability and enhanced oxidative stress. Potential mechanisms for beneficial effects of exogenous arginine in sepsis include enhanced (protein) metabolism, improved microcirculation and organ function, effects on immune function and antibacterial effects, improved gut function, and an antioxidant role of arginine. We recently performed a study indicating that arginine can be given to septic patients without major effects on hemodynamics, suggesting that more studies can be conducted on the effects of arginine supplementation in septic patients.


Reduced citrulline production in sepsis is related to diminished de novo arginine and nitric oxide production
            (Luiking et al., 2009) Download
BACKGROUND: L-Arginine is an important precursor of nitric oxide (NO) and protein synthesis. Arginine is produced in the body (mainly kidney) by de novo production from citrulline and by protein breakdown. Arginine availability appears to be limited in sepsis. OBJECTIVE: The objective was to compare arginine and citrulline metabolism in septic patients and nonseptic control patients in an intensive care unit (ICU) and in healthy control subjects. DESIGN: Ten patients with septic shock, 7 critically ill control patients, and 16 healthy elderly subjects were studied. Metabolism was measured by using a primed continuous (2 h) stable-isotope infusion protocol. NO production was calculated as the conversion rate of arginine to citrulline; de novo arginine production was calculated as the conversion rate of citrulline to arginine. Arterial blood (arterialized venous blood in healthy subjects) was collected for the measurement of amino acid enrichment and concentrations. Data are reported as means +/- SDs. RESULTS: Whole-body citrulline production was significantly lower in septic patients (4.5 +/- 2.1 micromol . kg(-1) . h(-1)) than in ICU control patients (10.1 +/- 2.9 micromol . kg(-1) . h(-1); P < 0.01) and in healthy control subjects (13.7 +/- 4.1 micromol . kg(-1) . h(-1); P < 0.001). Accordingly, de novo arginine production was lower in patients with sepsis (3.3 +/- 3.7 micromol . kg(-1) . h(-1)) than in healthy controls (11.9 +/- 6.6 micromol . kg(-1) . h(-1); P < 0.01) and tended to be lower in septic patients than in ICU control patients (10.9 +/- 9.4 micromol . kg(-1) . h(-1); P = 0.05). NO production was lower in septic patients than in healthy control subjects (P < 0.01), whereas a larger part of arginine was converted to urea in sepsis. CONCLUSIONS: Citrulline production is severely low in patients with sepsis and is related to diminished de novo arginine and NO production. These metabolic alterations contribute to reduced citrulline and arginine availability, and these findings warrant further studies of therapeutic nutritional interventions to restore arginine metabolism in sepsis.

Serum concentrations of vitamin A and oxidative stress in critically ill patients with sepsis
            (Ribeiro Nogueira et al., 2009) Download
INTRODUCTION: Sepsis is one of the main causes of mortality in patients in Intensive Care Units. As a result of the systemic inflammatory response and of the decrease of the aerobic metabolism in sepsis, the oxidative stress occurs. Vitamin A is recognized by the favorable effect that it exerts on the immune response to infections and antioxidant action. OBJECTIVE: To bring new elements for reviewing of the nutritional support addressed to critically ill patients with sepsis, with emphasis to vitamin A. METHODS: Critically ill patients with sepsis had circulating concentrations of retinol, beta-carotene, thiobarbituric acid-reactive substances (TBARS) and C-reactive protein (CRP) measured in Medicosurgical Intensive Care Unit in the city of Rio de Janeiro, Brazil. The patients were divided into two groups: patients who were receiving nutritional support and those without support. At the act of the patient's admission, APACHE II score was calculated. RESULTS: 46 patients were studied (with diet n = 24 and without diet n = 22). Reduced levels of retinol and beta-carotene were found in 65.2% and 73.9% of the patients, respectively. Among the patients who presented lower concentrations of CRP it was found higher beta-carotene inadequacy (64.8%) and 50% of retinol inadequacy. There was no significant difference as regards retinol, TBARS and APACHE II levels among the patients with and without nutritional support. However, higher levels of CRP (p = 0.001) and lower levels of serum beta-carotene (p = 0.047) were found in patients without nutritional support. CONCLUSIONS: Septic patients presented an important inadequacy of retinol and beta-carotene. The present study bring elements to the elaboration/review of the nutritional protocol directed to the group studied, especially as regards vitamin A intake.

Antioxidant therapy in critically septic patients
            (Rinaldi et al., 2009) Download
Critical illness and particularly sepsis are associated with a significant redox imbalance resulting from an increased production of oxidant species and a decrease in endogenous antioxidant defences. In critical patients sources of oxidative stress include the mitochondrial respiratory electron transport chain, xanthine oxidase activation, the respiratory burst associated with neutrophil activation, and arachidonic acid metabolism. Several endogenous antioxidants have been identified including enzymes, like superoxide dismutases and glutathione peroxidase, vitamins and other molecules such as uric acid and bilirubin. Recent studies pointed out the correlations between oxidative stress, systemic inflammatory response and apoptosis. Prospective randomized clinical trials regarding antioxidant therapy in critical illness provide increasing evidence in support of selenium, glutamine and omega-3 fatty acids. In particular selenium seems to improve clinical outcome in terms of infections and organ failure, glutamine has been associated with a significant reduction in infectious complications and omega-3 fatty acids could be particularly efficacious in sepsis. Melatonin is a promising molecule that deserves the attention of future research, as well as vitamin C. Further studied should also try to establish the more beneficial combination of antioxidants, as well as the doses, and the timing of administration. When such problems will be resolved hopefully results about antioxidant therapy in critical illness will be more univocal and promising.


Impaired microvascular perfusion in sepsis requires activated coagulation and P-selectin-mediated platelet adhesion in capillaries
            (Secor et al., 2010) Download
PURPOSE: Impaired microvascular perfusion in sepsis is not treated effectively because its mechanism is unknown. Since inflammatory and coagulation pathways cross-activate, we tested if stoppage of blood flow in septic capillaries is due to oxidant-dependent adhesion of platelets in these microvessels. METHODS: Sepsis was induced in wild type, eNOS(-/-), iNOS(-/-), and gp91phox(-/-) mice (n = 14-199) by injection of feces into the peritoneum. Platelet adhesion, fibrin deposition, and blood flow stoppage in capillaries of hindlimb skeletal muscle were assessed by intravital microscopy. Prophylactic treatments at the onset of sepsis were intravenous injection of platelet-depleting antibody, P-selectin blocking antibody, ascorbate, or antithrombin. Therapeutic treatments (delayed until 6 h) were injection of ascorbate or the glycoprotein IIb/IIIa inhibitor eptifibatide, or local superfusion of the muscle with NOS cofactor tetrahydrobiopterin or NO donor S-nitroso-N-acetylpenicillamine (SNAP). RESULTS: Sepsis at 6-7 h markedly increased the number of stopped-flow capillaries and the occurrence of platelet adhesion and fibrin deposition in these capillaries. Platelet depletion, iNOS and gp91phox deficiencies, P-selectin blockade, antithrombin, or prophylactic ascorbate prevented, whereas delayed ascorbate, eptifibatide, tetrahydrobiopterin, or SNAP reversed, septic platelet adhesion and/or flow stoppage. The reversals by ascorbate and tetrahydrobiopterin were absent in eNOS(-/-) mice. Platelet adhesion predicted 90% of capillary flow stoppage. CONCLUSION: Impaired perfusion and/or platelet adhesion in septic capillaries requires NADPH oxidase, iNOS, P-selectin, and activated coagulation, and is inhibited by intravenous administration of ascorbate and by local superfusion of tetrahydrobiopterin and NO. Reversal of flow stoppage by ascorbate and tetrahydrobiopterin may depend on local eNOS-derived NO which dislodges platelets from the capillary wall.

Highly purified vitamin B2 presents a promising therapeutic strategy for sepsis and septic shock
            (Toyosawa et al., 2004) Download
Highly purified vitamin B2 (riboflavin 5'-sodium phosphate; purity > 97%) treatment by intravenous infusion at doses above those used clinically to treat vitamin B2 deficiency showed therapeutic effects in mice not only in cases of endotoxin- and exotoxin-induced shock but also in cases of gram-negative and gram-positive bacterial infection even after the toxemia had already begun.


Septic impairment of capillary blood flow requires nicotinamide adenine dinucleotide phosphate oxidase but not nitric oxide synthase and is rapidly reversed by ascorbate through an endothelial nitric oxide synthase-dependent mechanism
            (Tyml et al., 2008) Download
OBJECTIVE: To determine the roles of nitric oxide synthase (NOS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in the impairment of capillary blood flow in sepsis and in the reversal of this impairment by ascorbate. DESIGN: Prospective, controlled laboratory study. SETTING: Animal laboratory in research institute. SUBJECTS: Adult male wild type (WT), neuronal nitric oxide synthase (nNOS)-/-, inducible NOS (iNOS)-/-, endothelial NOS (eNOS)-/-, and gp91phox-/- mice. INTERVENTIONS: Sepsis was induced by feces injection into peritoneum (FIP). A bolus of ascorbate or NADPH oxidase inhibitor apocynin was injected intravenously at 6 hrs post-FIP. Alternatively, NOS cofactor (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4) or nitric oxide donor S-nitroso-N-acetylpenicillamine was superfused on the surface of the extensor digitorum longus muscle. MEASUREMENTS AND MAIN RESULTS: Capillary blood flow impairment and NOS activity in the extensor digitorum longus muscle were measured by intravital microscopy and by enzymatic assay, respectively. Sepsis at 6 hrs impaired flow in WT mice. Apocynin, and knockout of gp91phox but not of any NOS isoforms, rescued this impairment. Constitutive NOS activity was unaffected by sepsis, but it was abolished by nNOS knockout (iNOS activity was negligible in all mice). Ascorbate rapidly (10 mins) rescued impaired flow in WT, nNOS-/-, iNOS-/- but not eNOS-/- mice. Ascorbate also improved survival of WT mice after FIP. BH4 and SNAP rescued flow in WT mice, while BH4 failed to rescue it in eNOS-/- mice. CONCLUSION: Capillary blood flow impairment in septic skeletal muscle requires NADPH oxidase but not NOS, and it is rapidly reversed by ascorbate and BH4 through an eNOS-dependent mechanism.

Acute oral leucine administration stimulates protein synthesis during chronic sepsis through enhanced association of eukaryotic initiation factor 4G with eukaryotic initiation factor 4E in rats
            (Vary, 2007) Download
Sepsis induces the loss of muscle proteins by impairing skeletal muscle protein synthesis through an inhibition of messenger RNA (mRNA) translation initiation. Amino acids and Leu (Leu) in particular stimulate mRNA translation initiation. The experiments were designed to test the effects of Leu on potential signal transduction pathways that may be important in accelerating mRNA translation initiation in skeletal muscle of rats with chronic (5-6 d) septic intra-abdominal abscess. Gastrocnemius from male Sprague Dawley rats gavaged with Leu or water were sampled 5-6 d following development of an intra-abdominal sterile or septic abscess. Gavage with Leu stimulated protein synthesis and enhanced the assembly of the active eukaryotic initiation factor (eIF)4G-eIF4E complex. Increased assembly of the active eIF4G-eIF4E complex was associated with a robust rise in phosphorylation of eIF4G(Ser(1108)) and a decreased assembly of inactive eIF4E binding protein-1 (4E-BP1)-eIF4E complex in both sterile inflammatory and septic rats. The reduced assembly of 4E-BP1-eIF4E complex was associated with an increase in phosphorylation of 4E-BP1 in the gamma-form following Leu gavage. Phosphorylation of 70-kDa ribosomal protein S6 kinase on Thr(389) was also increased following Leu gavage, as well as the phosphorylation of mammalian target of rapamycin on Ser(2448) or Ser(2481). In contrast, phosphorylation of protein kinase B (PKB) on Thr(308) or Ser(473) was not augmented following Leu gavage in septic rats. We conclude that Leu stimulates a PKB-independent signal pathway elevating the eIF4G-eIF4E complex assembly through increased phosphorylation of eIF4G and decreased association of 4E-BP1 with eIF4E in skeletal muscle during sepsis.

Mechanism of action of vitamin C in sepsis: ascorbate modulates redox signaling in endothelium
            (Wilson, 2009) Download
Circulating levels of vitamin C (ascorbate) are low in patients with sepsis. Parenteral administration of ascorbate raises plasma and tissue concentrations of the vitamin and may decrease morbidity. In animal models of sepsis, intravenous ascorbate injection increases survival and protects several microvascular functions, namely, capillary blood flow, microvascular permeability barrier, and arteriolar responsiveness to vasoconstrictors and vasodilators. The effects of parenteral ascorbate on microvascular function are both rapid and persistent. Ascorbate quickly accumulates in microvascular endothelial cells, scavenges reactive oxygen species, and acts through tetrahydrobiopterin to stimulate nitric oxide production by endothelial nitric oxide synthase. A major reason for the long duration of the improvement in microvascular function is that cells retain high levels of ascorbate, which alter redox-sensitive signaling pathways to diminish septic induction of NADPH oxidase and inducible nitric oxide synthase. These observations are consistent with the hypothesis that microvascular function in sepsis may be improved by parenteral administration of ascorbate as an adjuvant therapy.


Arginine: mediator or modulator of sepsis?
            (Zaloga et al., 2004) Download
Arginine is a conditionally essential amino acid that plays pivotal roles in maintaining body homeostasis. Arginine is a substrate for protein synthesis but can also be metabolized to various bioactive compounds that include nitric oxide, ornithine, polyamines, creatine phosphate, agmatine, and dimethylarginines. Arginine produces physiologic effects via nitric oxide dependent and independent pathways. Nitric oxide is important for the modulation of vascular tone, inflammation, immune function, endothelial function, platelet and leukocyte adherence, and neurotransmission. Nitric oxide modulates many biochemical processes important for the response to sepsis. Arginine, independent of nitric oxide, is important for growth, wound healing, cardiovascular function, immune function, inflammatory responses, energy metabolism, urea cycle function, and other metabolic processes. Arginine supplementation improves outcomes in animals with sepsis, wounds, ischemia-reperfusion injury, and following thermal injury. Enteral administration of arginine improves endothelial function but has little effect upon hemodynamics during human sepsis. An analysis of clinical studies using enteral formulas with supplemental arginine suggests benefits upon outcome, with no evidence of significant detrimental effects.


References

Berger, M. M. and R. L. Chiolero (2007), ‘Antioxidant supplementation in sepsis and systemic inflammatory response syndrome’, Crit Care Med, 35 (9 Suppl), S584-90. PubMed: 17713413
Biolo, G., R. Antonione, and M. De Cicco (2007), ‘Glutathione metabolism in sepsis’, Crit Care Med, 35 (9 Suppl), S591-5. PubMed: 17713414
Ginde, A. A., C. A. Camargo, Jr., and N. I. Shapiro (2011), ‘Vitamin D Insufficiency and Sepsis Severity in Emergency Department Patients With Suspected Infection’, Acad Emerg Med, PubMed: 21518095
Kao, C. C., et al. (2009), ‘Arginine, citrulline and nitric oxide metabolism in sepsis’, Clin Sci (Lond), 117 (1), 23-30. PubMed: 19105791
Kapoor, A. and C. Thiemermann (2011), ‘Niacin as a novel therapy for septic shock?’, Crit Care Med, 39 (2), 410-11. PubMed: 21248526
Kwon, W. Y., et al. (2011), ‘Niacin attenuates lung inflammation and improves survival during sepsis by downregulating the nuclear factor-kappaB pathway’, Crit Care Med, 39 (2), 328-34. PubMed: 20975550
Luiking, Y. C. and N. E. Deutz (2007), ‘Exogenous arginine in sepsis’, Crit Care Med, 35 (9 Suppl), S557-63. PubMed: 17713409
Luiking, Y. C., et al. (2009), ‘Reduced citrulline production in sepsis is related to diminished de novo arginine and nitric oxide production’, Am J Clin Nutr, 89 (1), 142-52. PubMed: 19056593
Ribeiro Nogueira, C., et al. (2009), ‘Serum concentrations of vitamin A and oxidative stress in critically ill patients with sepsis’, Nutr Hosp, 24 (3), 312-17. PubMed: 19721904
Rinaldi, S., F. Landucci, and A. R. De Gaudio (2009), ‘Antioxidant therapy in critically septic patients’, Curr Drug Targets, 10 (9), 872-80. PubMed: 19799541
Secor, D., et al. (2010), ‘Impaired microvascular perfusion in sepsis requires activated coagulation and P-selectin-mediated platelet adhesion in capillaries’, Intensive Care Med, 36 (11), 1928-34. PubMed: 20689935
Toyosawa, T., et al. (2004), ‘Highly purified vitamin B2 presents a promising therapeutic strategy for sepsis and septic shock’, Infect Immun, 72 (3), 1820-23. PubMed: 14977995
Tyml, K., F. Li, and J. X. Wilson (2008), ‘Septic impairment of capillary blood flow requires nicotinamide adenine dinucleotide phosphate oxidase but not nitric oxide synthase and is rapidly reversed by ascorbate through an endothelial nitric oxide synthase-dependent mechanism’, Crit Care Med, 36 (8), 2355-62. PubMed: 18596627
Vary, T. C. (2007), ‘Acute oral leucine administration stimulates protein synthesis during chronic sepsis through enhanced association of eukaryotic initiation factor 4G with eukaryotic initiation factor 4E in rats’, J Nutr, 137 (9), 2074-79. PubMed: 17709445
Wilson, J. X. (2009), ‘Mechanism of action of vitamin C in sepsis: ascorbate modulates redox signaling in endothelium’, Biofactors, 35 (1), 5-13. PubMed: 19319840
Zaloga, G. P., et al. (2004), ‘Arginine: mediator or modulator of sepsis?’, Nutr Clin Pract, 19 (3), 201-15. PubMed: 16215108