Association between bilirubin and biomarkers of metabolic health and oxidative stress in the MARK-AGE cohort.

Recent studies have shown that elevated concentrations of unconjugated bilirubin (UCB) may be a protective host factor against the development of noncommunicable diseases (NCDs), whereas low levels of UCB are associated with the opposite effect. The results of this European study, in which 2,489 samples were tested for their UCB concentration using high-performance liquid chromatography (HPLC) and additional data from the MARK-AGE database were used for analysis, provide further evidence that elevated UCB concentrations are linked to a lower risk of developing NCDs and may act as a predictive marker of biological aging as individuals with elevated UCB concentrations showed favorable outcomes in metabolic health and oxidative-stress-related biomarkers. These findings underline the significance of studying individuals with moderate hyperbilirubinemia and investigate UCB routinely, also in the setting of aging, since this condition affects millions of people worldwide but has been underrepresented in clinical research and practice until now.

Maternal Diet High in Linoleic Acid Alters Offspring Lipids and Hepatic Regulators of Lipid Metabolism in an Adolescent Rat Model.

Linoleic acid (LA), an n-6 polyunsaturated fatty acid (PUFA), is essential for fetal growth and development. A maternal high LA (HLA) diet alters cardiovascular development in adolescent rats and hepatic function in adult rats in a sex-specific manner. We investigated the effects of an HLA diet on adolescent offspring hepatic lipids and hepatic lipid metabolism gene expression, and the ability of the postnatal diet to alter these effects. Female Wistar Kyoto rats were fed low LA (LLA; 1.44% energy from LA) or high LA (HLA; 6.21% energy from LA) diets during pregnancy and gestation/lactation. Offspring, weaned at postnatal day (PN) 25, were fed LLA or HLA and euthanised at PN40 (n = 6-8). Maternal HLA increased circulating uric acid, decreased hepatic cholesterol and increased hepatic Pparg in males, whereas only hepatic Srebf1 and Hmgcr increased in females. Postnatal (post-weaning) HLA decreased liver weight (% body weight) and increased hepatic Hmgcr in males, and decreased hepatic triglycerides in females. Maternal and postnatal HLA had an interaction effect on Lpl, Cpt1a and Pparg in females. These findings suggest that an HLA diet both during and after pregnancy should be avoided to improve offspring disease risk.

A Bioactive Disintegrable Polymer Nanoparticle for Synergistic Vascular Anticalcification.

Although poly(aspartic acid) (PASP), a strong calcium chelating agent, may be potentially effective in inhibition of vascular calcification, its direct administration may lead to side effects. In this study, we employed polysuccinimide, a precursor of PASP, to prepare targeted polysuccinimide-based nanoparticles (PSI NPs) that not only acted as a prodrug but also functioned as a carrier of additional therapeutics to provide powerful synergistic vascular anticalcification effect. This paper shows that chemically modified PSI-NPs can serve as effective nanocarriers for loading of hydrophobic drugs, in addition to anticalcification and antireactive oxygen species (anti-ROS) activities. Curcumin (Cur), with high loading efficiency, was encapsulated into the NPs. The NPs were stable for 16 h in physiological conditions and then slowly dissolved/hydrolyzed to release the therapeutic PASP and the encapsulated drug. The drug release profile was found to be in good agreement with the NP dissolution profile such that complete release occurred after 48 h at physiological conditions. However, under acidic conditions, the NPs were stable, and Cur cumulative release reached only 30% after 1 week. Though highly effective in the prevention of calcium deposition, PSI NPs could not prevent the osteogenic trans-differentiation of vascular smooth muscle cells (VSMCs). The presence of Cur addressed this problem. It not only further reduced ROS level in macrophages but also prevented osteogenic differentiation of VSMCs in vitro. The NPs were examined in vivo in a rat model of vascular calcification induced by kidney failure through an adenine diet. The inclusion of Cur and PSI NPs combined the therapeutic effects of both. Cur-loaded NPs significantly reduced calcium deposition in the aorta without adversely affecting bone integrity or noticeable side effects/toxicity as examined by organ histological and serum biochemistry analyses.

Spiky Silver-Iron Oxide Nanohybrid for Effective Dual-Imaging and Synergistic Thermo-Chemotherapy.

Nanophotothermal therapy based on nanoparticles (NPs) that convert near-infrared (NIR) light to generate heat to selectively kill cancer cells has attracted immense interest due to its high efficacy and being free of ionizing radiation damage. Here, for the first time, we have designed a novel nanohybrid, silver-iron oxide NP (AgIONP), which was successfully tuned for strong absorbance at NIR wavelengths to be effective in photothermal treatment and dual-imaging strategy using MRI and photoacoustic imaging (PAI) in a cancer model in vivo and in vitro, respectively. We strategically combine the inherent anticancer activity of silver and photothermal therapy to render excellent therapeutic capability of AgIONPs. In vitro phantoms and in vivo imaging studies displayed preferential uptake of folate-targeted NPs in a cancer mice model, indicating the selective targeting efficiency of NPs. Importantly, a single intravenous injection of NPs in a cancer mice model resulted in significant tumor reduction, and photothermal laser resulted in a further substantial synergistic decrease in tumor size. Additionally, biosafety and biochemical assessment performed in mice displayed no significant difference between NP treatment and control groups. Overall, our folic acid AgIONPs displayed excellent potential in the simultaneous application for safe and successful targeted synergistic photothermal treatment and imaging of a cancer model.

Changes in Essential Fatty Acids and Ileal Genes Associated with Metabolizing Enzymes and Fatty Acid Transporters in Rodent Models of Cystic Fibrosis.

Cystic fibrosis (CF), the result of mutations in the CF transmembrane conductance regulator (CFTR), causes essential fatty acid deficiency. The aim of this study was to characterize fatty acid handling in two rodent models of CF; one strain which harbors the loss of phenylalanine at position 508 (Phe508del) in CFTR and the other lacks functional CFTR (510X). Fatty acid concentrations were determined using gas chromatography in serum from Phe508del and 510X rats. The relative expression of genes responsible for fatty acid transport and metabolism were quantified using real-time PCR. Ileal tissue morphology was assessed histologically. There was an age-dependent decrease in eicosapentaenoic acid and the linoleic acid:α-linolenic acid ratio, a genotype-dependent decrease in docosapentaenoic acid (n-3) and an increase in the arachidonic acid:docosahexaenoic acid ratio in Phe508del rat serum, which was not observed in 510X rats. In the ileum, Cftr mRNA was increased in Phe508del rats but decreased in 510X rats. Further, Elvol2, Slc27a1, Slc27a2 and Got2 mRNA were increased in Phe508del rats only. As assessed by Sirius Red staining, collagen was increased in Phe508del and 510X ileum. Thus, CF rat models exhibit alterations in the concentration of circulating fatty acids, which may be due to altered transport and metabolism, in addition to fibrosis and microscopic structural changes in the ileum.

Sexual dimorphism: increased sterol excretion leads to hypocholesterolaemia in female hyperbilirubinaemic Gunn rats.

Circulating bilirubin is associated with reduced serum cholesterol concentrations in humans and in hyperbilirubinaemic Gunn rats. However, mechanisms contributing to hypocholesterolaemia remain unknown. Therefore, this study aimed to investigate cholesterol synthesis, transport and excretion in mutant Gunn rats. Adult Gunn and control rats were assessed for daily faecal sterol excretion using metabolic cages, and water was supplemented with [1-13 C]-acetate to determine cholesterol synthesis. Bile was collected to measure biliary lipid secretion. Serum and liver were collected for biochemical analysis and for gene/protein expression using RT-qPCR and western blot, respectively. Additionally, serum was collected and analysed from juvenile rats. A significant interaction of sex, age and phenotype on circulating lipids was found with adult female Gunn rats reporting significantly lower cholesterol and phospholipids. Female Gunn rats also demonstrated elevated cholesterol synthesis, greater biliary lipid secretion and increased total faecal cholesterol and bile acid excretion. Furthermore, they possessed increased hepatic low-density lipoprotein (LDL) receptor and SREBP2 expression. In contrast, there were no changes to sterol metabolism in adult male Gunn rats. This is the first study to demonstrate elevated faecal sterol excretion in female hyperbilirubinaemic Gunn rats. Increased sterol excretion creates a negative intestinal sterol balance that is compensated for by increased cholesterol synthesis and LDL receptor expression. Therefore, reduced circulating cholesterol is potentially caused by increased hepatic uptake via the LDL receptor. Future studies are required to further evaluate the sexual dimorphism of this response and whether similar findings occur in females with benign unconjugated hyperbilirubinaemia (Gilbert's syndrome). KEY POINTS: Female adult hyperbilirubinaemic (Gunn) rats demonstrated lower circulating cholesterol, corroborating human studies that report a negative association between bilirubin and cholesterol concentrations. Furthermore, female Gunn rats had elevated sterol excretion creating a negative intestinal sterol balance that was compensated for by elevated cholesterol synthesis and increased hepatic low-density lipoprotein (LDL) receptor expression. Therefore, elevated LDL receptor expression potentially leads to reduced circulating cholesterol levels in female Gunn rats providing an explanation for the hypocholesterolaemia observed in humans with elevated bilirubin levels. This study also reports a novel interaction of sex with the hyperbilirubinaemic phenotype on sterol metabolism because changes were only reported in females and not in male Gunn rats. Future studies are required to further evaluate the sexual dimorphism of this response and whether similar findings occur in females with benign unconjugated hyperbilirubinaemia (Gilbert's syndrome).

Compression Socks Reduce Running-Induced Intestinal Damage.

ABSTRACT: Zadow, EK, Edwards, KH, Kitic, CM, Fell, JW, Adams, MJ, Singh, I, Kundur, A, Johnstone, ANB, Crilly, J, Bulmer, AC, Halson, SL, and, and Wu, SSX. Compression socks reduce running-induced intestinal damage. J Strength Cond Res 36(9): 2461-2464, 2022-Exercise is associated with a reduction in splanchnic blood flow that leads to the disruption of intestinal epithelium integrity, contributing to exercise-induced gastrointestinal syndrome. Strategies that promote intestinal blood flow during exercise may reduce intestinal damage, which may be advantageous for subsequent recovery and performance. This study aimed to explore if exercise-associated intestinal damage was influenced by wearing compression garments, which may improve central blood flow. Subjects were randomly allocated to wear compression socks ( n = 23) or no compression socks (control, n = 23) during a marathon race. Blood samples were collected 24 hours before and immediately after marathon and analyzed for intestinal fatty acid-binding protein (I-FABP) concentration as a marker of intestinal damage. The magnitude of increase in postmarathon plasma I-FABP concentration was significantly greater in control group (107%; 95% confidence interval [CI], 72-428%) when compared with runners wearing compression socks (38%; 95% CI, 20-120%; p = 0.046; d = 0.59). Wearing compression socks during a marathon run reduced exercise-associated intestinal damage. Compression socks may prove an effective strategy to minimize the intestinal damage component of exercise-induced gastrointestinal syndrome.

Serum metabolomics analysis reveals increased lipid catabolism in mildly hyperbilirubinemic Gilbert's syndrome individuals.

BACKGROUND: The protective role of mildly elevated bilirubin against CVD and diabetes mellitus type 2 (DMT2) is associated with a favorable lipid phenotype. As the mechanistic understanding of this protection in humans remains elusive, we aimed to assess the metabolomics profile of mildly hyperbilirubinemic (Gilbert's syndrome; GS) individuals especially targeting lipid catabolism. METHODS AND RESULTS: Using NMR serum metabolomics of 56 GS individuals and 56 age and gender-matched healthy controls, GS individuals demonstrated significantly greater concentrations of acetylcarnitine (+20%, p < 0.001) and the ketone bodies, 3-hydroxybutyric acid (+132%, p < 0.001), acetoacetic acid (+95%, p < 0.001) and acetone (+46%, p < 0.001). Metabolites associated with an increased mitochondrial lipid metabolism such as citrate (+15%, p < 0.001), anaplerotic amino acid intermediates and creatinine were significantly greater and creatine significantly reduced in GS individuals. Stimulators of lipid catabolism including AMPK (+59%, p < 0.001), pPPARα (+24%, p < 0.001) and T3 (+9%, p = 0.009) supported the metabolomics data while concomitantly blood glucose and insulin (-33%, p = 0.002) levels were significantly reduced. We further showed that the increased lipid catabolism partially mediates the favorable lipid phenotype (lower triglycerides) of GS individuals. Increased trimethylamine (+35%, p < 0.001) indicated changes in trimethylamine metabolism, an emerging predictor of metabolic health. CONCLUSION: We showed an enhanced lipid catabolism in mildly hyperbilirubinemic individuals, novel evidence as to why these individuals are leaner and protected against chronic metabolic diseases emphasizing bilirubin to be a promising future target in obese and dyslipidemia patients.

Gilbert's Syndrome and the Gut Microbiota - Insights From the Case-Control BILIHEALTH Study.

The heme catabolite bilirubin has anti-inflammatory, anti-oxidative and anti-mutagenic effects and its relation to colorectal cancer (CRC) risk is currently under evaluation. Although the main metabolic steps of bilirubin metabolism, including the formation of stercobilin and urobilin, take place in the human gastrointestinal tract, potential interactions with the human gut microbiota are unexplored. This study investigated, whether gut microbiota composition is altered in Gilbert's Syndrome (GS), a mild form of chronically elevated serum unconjugated bilirubin (UCB) compared to matched controls. Potential differences in the incidence of CRC-associated bacterial species in GS were also assessed. To this end, a secondary investigation of the BILIHEALTH study was performed, assessing 45 adults with elevated UCB levels (GS) against 45 age- and sex-matched controls (C). Fecal microbiota analysis was performed using 16S rRNA gene sequencing. No association between mildly increased UCB and the composition of the gut microbiota in this healthy cohort was found. The alpha and beta diversity did not differ between C and GS and both groups showed a typical representation of the known dominant phyla. Furthermore, no difference in abundance of Firmicutes and Proteobacteria, which have been associated with the mucosa of CRC patients were observed between the groups. A sequence related to the Christensenella minuta strain YIT 12065 was identified with a weak association value of 0.521 as an indicator species in the GS group. This strain has been previously associated with a lower body mass index, which is typical for the GS phenotype. Overall, sex was the only driver for an identifiable difference in the study groups, as demonstrated by a greater bacterial diversity in women. After adjusting for confounding factors and multiple testing, we can conclude that the GS phenotype does not affect the composition of the human gut microbiota in this generally healthy study group.

Pharmacokinetics of bilirubin-10-sulfonate and biliverdin in the rat.

BACKGROUND AND PURPOSE: Biliverdin (BV) administration induces antioxidant and anti-inflammatory effects, with previous reports also identifying anti-anaphylactic potential. Interestingly however, intra-duodenal administration of BV in rats leads to the formation of bilirubin-10-sulfonate (BRS), which might be responsible for BV's purported effects. EXPERIMENTAL APPROACH: This study aimed to assess the intravenous, intraperitoneal and intraduodenal pharmacokinetics of BRS and BV in order to assess their therapeutic potential in future studies. Bile and venous blood were intermittently collected before and after administration, which was subsequently analysed using liquid chromatography-mass spectrometry for quantification of bile pigment concentrations. KEY RESULTS: Interestingly, i.p. BRS administration led to a greater circulating concentration and had a reduced excretion rate, which resulted in a substantially elevated AUC180 when compared to BV administration. Furthermore, BRS was excreted intact in the bile, in contrast to BV which was excreted after chemical reduction and conjugation. Intraperitoneal and intraduodenal administration substantially increased blood BRS concentrations (p<0.05), however, the bioavailability of BV was higher than BRS following i.p. administration (i.p. BV 28.4%, BRS 15.5%) but lower following i.d. administration (i.d. BV 0.04%, BRS 0.07%), over 180 minutes. When BRS was administered i.v., BRS had a significantly (p<0.05) longer distribution (191.9 vs 54.1 minutes) half-life compared to BV, and significantly reduced (p<0.05) volume of distribution (0.026 vs 0.145 L kg-1). As a consequence, intraperitoneal and intraduodenal administration resulted in significantly greater blood concentrations of BRS (p<0.05) over 180 minutes. Therefore, BRS may be more likely to induce antioxidant or molecular effects, when compared to BV, due to greater concentrations and a longer half-life. CONCLUSIONS AND IMPLICATIONS: Cumulatively, these data demonstrate that BRS has a superior pharmacokinetic profile when compared to BV, which is a result of its resistance to hepatic metabolism and excretion. These data therefore provide a basis to explore the capacity of BRS to protect from inflammatory pathology.

Effect of warming and infusion of red blood cell concentrates on markers of haemolysis: An ex vivo simulation study.

BACKGROUND: Transfusion of red blood cell (RBC) concentrates is a common procedure to restore blood volume and tissue oxygen delivery in patients with trauma. Although RBC warmers may prevent hypothermia, some warming or infusion equipment may lead to haemolysis and patient injury. OBJECTIVES: The aim of this study was to test the effect of (i) RBC warming and (ii) administration via manual vs. pump infusion on haemolysis. METHODS: This experimental ex vivo study studied haemolysis markers of RBC injury. The sample consisted of 90 RBC infusions in two simulations, randomly, 45 warmed RBC infusions and 45 nonwarmed RBC infusions, in two or three stages: before the intervention (baseline-warming, N= 45; nonwarming, N= 45), after water bath warming at 42 °C (warmed, N= 45), and then after the warmed or nonwarmed RBCs were infused by manual or pump infusion at a rate of 100 mL/h (infusion-warming, N= 45; nonwarming, N= 45). RESULTS: Warmed RBCs showed significantly lower total haemoglobin (Hb) and haematocrit levels and increase in free Hb levels, haemolysis levels, and lactate dehydrogenase (LDH) activity (all p<0.05) than baseline RBCs. Pump infusion RBCs were associated with reduced total Hb and increased free Hb, haemolysis, and potassium (K) levels (all p<0.05) compared with warmed RBCs. In contrast, manual infusion of warmed RBCs resulted in significantly reduced total Hb levels and increased LDH activity (both <0.05). After infusion, total Hb, free Hb, haematocrit, haemolysis, and LDH values were significantly different for warmed vs. nonwarmed RBCs (p<0.05). CONCLUSIONS: Haemolysis biomarkers increase with RBC warming and infusion, especially when using infusion pumps. Critically ill patients should be carefully monitored for possible complications during and after RBC infusion.

Biliverdin and bilirubin sulfonate inhibit monosodium urate induced sterile inflammation in the rat.

BACKGROUND: Biliverdin, a by-product of haem catabolism, possesses potent endogenous antioxidant and anti-inflammatory properties. Bilirubin-C10-sulfonate (BRS), an active metabolite formed after enteral administration of BV in the rat, also possess antioxidant properties. Therefore, we investigated the anti-inflammatory and antioxidant activity of BV and BRS in an in vivo model of monosodium urate induced sterile inflammation. METHODS: Subcutaneous air pouches were created on the dorsal flanks of Wistar rats (10-12 weeks of age). Prior to stimulation of the 6-day old pouch with monosodium urate (25 mg), groups were pre-treated with intraperitoneal BRS (27 mg/kg) and BV (27 mg/kg). Total and differential leukocyte counts were determined in pouch fluid aspirate at 1, 6, 12, 24 and 48 h after monosodium urate stimulation. Biliverdin (BV), BRS and unconjugated bilirubin (UCB) concentrations in the serum and pouch fluid were quantified using liquid chromatography-mass spectrometry. Pouch fluid cytokine concentrations (IL-1ß, IL-1α, TNF-α, IL-17A, IL-12, GM-CSF, IL-33, IFN-γ, IL-18, IL-10, MCP-1, CXCL-1 and IL-6) were assessed after 6 h. In addition, 24 h protein carbonyl and chloramine concentrations were assessed in pouch fluid using ELISA and spectrophotometry, respectively. RESULTS: BRS and BV significantly (p < 0.05) inhibited leukocyte (total, neutrophil and macrophage) infiltration into the pouch fluid from 6 to 48 h. For example, after 6 h neutrophil counts decreased following BRS (0.32 ± 0.11 × 106 cells mL-1) and BV (0.17 ± 0.03 × 106 cells mL-1) compared to MSU only (3.51 ± 1.07 × 106 cells mL-1). Both BV and BRS significantly (p < 0.05) reduced pouch GM-CSF (BV: 5.8 ± 1.2 pg mL-1, BRS: 6.9 ± 1.5 pg mL-1 vs MSU only: 13.0 ± 1.9 pg mL-1) and MCP-1 concentrations at 6 h (BV: 1804 ± 269 pg mL-1, BRS: 7927 ± 2668 pg mL-1 vs MSU only: 17,290 ± 4503 pg ml-1), whilst BV additionally inhibited IL-6 (4354 ± 977 pg mL-1 vs MSU only: 25,070 ± 5178 pg mL-1) and IL-18 (17.6 ± 2.0 pg mL-1 vs MSU only: 81.5 ± 19.9 pg mL-1) concentrations at 6 h (p < 0.05). Despite these differences, no change in pouch chloramine or protein carbonyl concentrations occurred at 24 h (p > 0.05). Serum BV concentrations rapidly diminished over 6 h, however, BRS was readily detected in the serum over 48 h, and in pouch fluid over 12 h. CONCLUSIONS: This study is the first to elucidate anti-inflammatory activity of BRS and the efficacy of BV administration in a model of gouty inflammation. Reduced leukocyte infiltration and cytokine production in response to sterile inflammation further support the importance of these molecules in physiology and their therapeutic potential in sterile inflammation.

Targeted cryoprecipitate transfusion in severe traumatic haemorrhage.

BACKGROUND: Severe traumatic haemorrhage is the leading cause of death in young adults. Trauma Induced Coagulopathy is a complex and multifactorial phenomenon associated with severe traumatic haemorrhage. Fibrinogen is one of the first coagulation factors to become depleted in TIC and evidence suggests that severely injured trauma patients with hypofibrinogenaemia have poor outcomes. It is postulated that early fibrinogen replacement can improve clinical outcomes. This study investigated cryoprecipitate transfusion in hyopfibrinogeneamic trauma patients. METHODS: This retrospective, single center, observational study investigated the use of cryoprecipitate in severely injured trauma patients admitted to an Australian Level I Trauma Centre. The primary outcome was time to administration of cryoprecipitate after identification of hypofibrinogenaemia using ROTEM (FIBTEM A5). Data collected included demographics, ISS, laboratory values of coagulation and blood product usage. RESULTS: 71 patients received cryoprecipitate with a median time of 61 minutes [IQR 37-93] from FIBTEM A5 result to initial cryoprecipitate administration. At 24 hours following admission to ED, Clauss Fibrinogen levels increased by 1.30g/L [IQR 0.45-1.85] and FIBTEM A5 assay increased by 8mm [IQR 3.0-11.3]. Changes in both variables were highly significant (p<0.001) and Clauss Fibrinogen versus FIBTEM A5 values showed moderate to strong correlation (R=0.75-0.80). CONCLUSION: This study demonstrated that early administration of cryoprecipitate was both feasible and efficacious in fibrinogen replacement in severe traumatic haemorrhage. High-level evidence supporting cryoprecipitate or fibrinogen concentrate replacement with regards to efficacy and feasibility is required to guide future clinical practice. This study provided baseline data to inform the design of further clinical trials investigating fibrinogen replacement in traumatic haemorrhage.

Development of an intravaginal ring for the topical delivery of Aurora kinase A inhibitor, MLN8237.

Human papilloma virus (HPV) is the main culprit in cervical cancers. Although the HPV vaccine is now available, the slow and gradual process for HPV cancers to form means little will change, even for vaccinated individuals. This warrants the development of new therapeutic strategies in both the newly diagnosed and recurrent patients. We have previously shown that Alisertib (MLN8237), an Aurora A kinase inhibitor, potently and selectively kills HPV-positive cervical cancer cells. However, Alisertib is known for its unfavorable side effects when administered systemically. A targeted delivery approach is therefore warranted. The topical delivery of drugs to the cervix for the treatment of cervical cancer is an underexplored area of research that has the potential to significantly improve therapeutic outcome. Here, we design a novel topical drug delivery system for localized delivery in the vaginal tract using intravaginal silicone rings loaded with Alisertib. We assessed the suitability of the drug for the application and delivery method and develop a high-performance liquid chromatography method, then show that the vaginal rings were effective at releasing Alisertib over an extended period of time. Furthermore, we showed that Alisertib-loaded vaginal rings did not induce overt inflammation in the mouse vaginal tract. Our work has major translational implications for the future development of vaginal ring devices for the topical treatment of cervical cancer.

Targeted fibrinogen concentrate use in severe traumatic haemorrhage.

OBJECTIVE: Fibrinogen is one of the first coagulation factors to be depleted during traumatic haemorrhage, and evidence suggests hypofibrinogenaemia leads to poor outcomes. A number of fibrinogen replacement products are currently available, with no clear consensus on the ideal product to use in severe traumatic haemorrhage. We hypothesised that it will be possible to rapidly administer fibrinogen concentrate (FC) guided by rotational thromboelastometry (ROTEM) FIBTEM A5 in patients presenting with trauma haemorrhage. METHODS: We examined 36 consecutive patients with trauma admitted to a level 1 trauma centre in Australia who received FC as part of their initial resuscitation. ROTEM analysis was conducted at various time points from emergency department (ED) admission to 48 hours after admission. The primary outcome was time to administration of FC after identification of hypofibrinogenaemia using ROTEM FIBTEM A5. Data were collected on quantity and timing of product transfusion, demographics, Injury Severity Score and laboratory values of coagulation. Spearman rank order correlation was used to determine the correlation between FIBTEM A5 and Clauss fibrinogen (FibC). RESULTS: Thirty-six patients received FC as their initial form of fibrinogen replacement during the study. Patients were hypofibrinogenaemic by both FIBTEM A5 (6 mm) and FibC (1.7 g/L) on presentation to the ED. It took a median of 22 minutes (IQR, 17-30 minutes) from time of a FIBTEM A5 analysis to FC administration. Both parameters increased significantly (P < 0.05) by 24 hours after admission. CONCLUSION: This study suggests that administration of FC represents a rapid and feasible method to replace fibrinogen in severe traumatic haemorrhage. However, the optimal method for replacing fibrinogen in traumatic haemorrhage is controversial and large multicentre randomised controlled trials are needed to provide further evidence. This study provided baseline data to inform the design of further clinical trials investigating fibrinogen replacement in traumatic haemorrhage.

Elevated maternal linoleic acid reduces circulating leptin concentrations, cholesterol levels and male fetal survival in a rat model.

KEY POINTS: Linoleic acid consumption is increasing in Western populations. We investigated whether elevated linoleic acid in pregnancy was deleterious to mothers or offspring. Maternal and fetal body and organ weights were not affected by elevated linoleic acid consumption. Maternal lipids and leptin were altered following elevated linoleic acid consumption. Male offspring numbers were reduced following elevated linoleic acid consumption. ABSTRACT: Dietary intakes of linoleic acid (LA) have increased dramatically in Western populations, including in women of reproductive age. Pro-inflammatory effects of LA may have detrimental effects on maternal and offspring outcomes. We aimed to investigate whether consumption of a maternal diet with elevated LA altered maternal inflammatory or metabolic markers during pregnancy, fetal growth and/or the sex ratio of the offspring. Female Wistar Kyoto rats consumed a diet high in LA (HLA) (6.21% of energy) or a diet low in LA (LLA) (1.44% of energy) for 10 weeks prior to mating and during pregnancy. Pregnant rats were killed at embryonic day 20 (E20). There were no differences in maternal or fetal body weights or organ weights in the HLA group compared to the LLA group. There was no difference in maternal circulating cytokine concentrations between dietary groups. In the maternal liver, IL-1α concentrations were significantly lower, and TNF-α and IL-7 significantly higher in the HLA group. Total plasma cholesterol, LDL-cholesterol, HDL cholesterol and the total:HDL cholesterol ratio were lower in dams fed the HLA diet. mRNA expression of sterol regulatory element binding transcription factor 1 (SREBF-1) and leptin in maternal adipose tissue was lower in the HLA group, as were circulating leptin concentrations. The proportion of male fetuses was lower and circulating prostaglandin E metabolite concentrations were increased in the HLA group. In conclusion, consumption of a maternal diet high in linoleic acid alters cholesterol metabolism and prostaglandin E metabolite concentrations, which may contribute to the reduced proportion of male offspring.

Deletion of Biliverdin Reductase A in Myeloid Cells Promotes Chemokine Expression and Chemotaxis in Part via a Complement C5a--C5aR1 Pathway.

Biliverdin reductase (BVR)-A is a pleotropic enzyme converting biliverdin to bilirubin and a signaling molecule that has cytoprotective and immunomodulatory effects. We recently showed that biliverdin inhibits the expression of complement activation fragment 5a receptor one (C5aR1) in RAW 264.7 macrophages. In this study, we investigated the role of BVR-A in determining macrophage inflammatory phenotype and function via regulation of C5aR1. We assessed expression of C5aR1, M1-like macrophage markers, including chemokines (RANTES, IP-10), as well as chemotaxis in response to LPS and C5a in bone marrow-derived macrophages from BVR fl/fl and LysM-Cre:BVR fl / fl mice (conditional deletion of BVR-A in myeloid cells). In response to LPS, macrophages isolated from LysM-Cre:BVR fl/fl showed significantly elevated levels of C5aR1 as well as chemokines (RANTES, IP10) but not proinflammatory markers, such as iNOS and TNF. An increase in C5aR1 expression was also observed in peritoneal macrophages and several tissues from LysM-Cre:BVR fl/fl mice in a model of endotoxemia. In addition, knockdown of BVR-A resulted in enhanced macrophage chemotaxis toward C5a. Part of the effects of BVR-A deletion on chemotaxis and RANTES expression were blocked in the presence of a C5aR1 neutralizing Ab, confirming the role of C5a-C5aR1 signaling in mediating the effects of BVR. In summary, BVR-A plays an important role in regulating macrophage chemotaxis in response to C5a via modulation of C5aR1 expression. In addition, macrophages lacking BVR-A are characterized by the expression of M1 polarization-associated chemokines, the levels of which depend in part on C5aR1 signaling.

Unprecedented Microbial Conversion of Biliverdin into Bilirubin-10-sulfonate.

Biliverdin (BV) possesses antioxidant and anti-inflammatory properties, with previous reports identifying protection against oxidant and inflammatory injury in animal models. Recent reports indicate that intra-duodenal administration of BV results in the formation of an uncharacterised metabolite, which is potently absorbed into the blood and excreted into the bile. This compound may be responsible for protection against inflammatory responses. This study aimed to identify novel, enterally-derived BV metabolites and determine the source of their metabolic transformation. Rat duodena and bacterial cultures of Citrobacter youngae were treated with BV and subsequently analysed via high performance liquid chromatography/high resolution tandem mass spectrometry to identify and characterise metabolites of BV. A highly abundant metabolite was detected in duodenal wash and bacterial culture supernatants with a 663.215 m/z (3 ppm mass accuracy) and a composition of C33N4O9H36S, which conformed to the predicted structure of bilirubin-10-sulfonate (BRS) and possessed a λmax of 440 nm. Bilirubin-10-sulfonate was then synthesized for comparative LCMS/MS analysis and matched with that of the biologically formed BV metabolite. This report confirms the formation of a previously undocumented metabolite of BV in mammals, indicating that a new metabolic pathway likely exists for BV metabolism requiring enteric bacteria, Citrobacter youngae. These data may have important implications with regard to understanding and harnessing the therapeutic efficacy of oral BV administration.

Implications for maintaining vascular access device patency and performance: Application of science to practice.

INTRODUCTION: Vascular access devices are commonly inserted devices that facilitate the administration of fluids and drugs, as well as blood sampling. Despite their common use in clinical settings, these devices are prone to occlusion and failure, requiring replacement and exposing the patient to ongoing discomfort/pain, local vessel inflammation and risk of infection. A range of insertion and maintenance strategies are employed to optimize device performance; however, the evidence base for many of these mechanisms is limited and the mechanisms contributing to the failure of these devices are largely unknown. AIMS/OBJECTIVES: (1) To revisit existing understanding of blood, vessel physiology and biological fluid dynamics; (2) develop an understanding of the implications that different clinical practices have on vessel health, and (3) apply these understandings to vascular access device research and practice. METHOD: Narrative review of biomedical and bioengineering studies related to vascular access practice. RESULTS/OUTCOMES: Current vascular access device insertion and maintenance practice and policy are variable with limited clinical evidence to support the theoretical assumptions underpinning these regimens. This review demonstrates the physiological response to vascular access device insertion, flushing and infusion on the vein, blood components and blood flow. These appear to be associated with changes in intravascular fluid dynamics. Variable forces are at play that impact blood componentry and the endothelium. These may explain the mechanisms contributing to vascular access failure. CONCLUSION: This review provides an update to our current knowledge and understanding of vascular physiology and the hemodynamic response, challenging some previously held assumptions regarding vascular access device maintenance, which require further investigation.

Antithrombogenic peripherally inserted central catheters: overview of efficacy and safety.

INTRODUCTION: Thrombotic complications associated with peripherally inserted central catheters (PICCs) are common, as most synthetic materials when placed in the presence of serum often result in platelet activation, fibrin deposition, thrombotic occlusion, and potentially embolization. A current innovation focus has been the development of antithrombogenic catheter materials, including hydrophilic and hydrophobic surfaces. These are being incorporated into PICCs in an attempt to prevent the normal thrombotic cascade leading to patient harm. AREAS COVERED: This review focuses on the laboratory efficacy and clinical effectiveness of antithrombogenic PICCs to prevent PICC-associated thrombosis, as well as their efficiency and safety. This synthesis was informed by a systematic identification of published and unpublished laboratory and clinical studies evaluating these technologies. EXPERT COMMENTARY: A range of PICCs have been developed with antithrombogenic claims, using varying technologies. However, to date, there is no peer-reviewed laboratory research describing the individual PICCs' effectiveness. Despite promising early clinical trials, adequately powered trials to establish efficacy, effectiveness, efficiency, and safety of all of the individual products have not yet been undertaken.