Assessing the impact of physical, mental and cognitive impairments on health-related quality of life in sepsis survivors following intensive care admission in New Zealand.

Aim: To assess the impact of physical, mental and cognitive impairments on health-related quality-of-life (QoL) of individuals who have survived sepsis after admission to an Intensive Care Unit (ICU) in New Zealand.

Methods: Survivors from a trial investigating vitamin C as an adjunctive therapy in patients with sepsis in Christchurch Hospital ICU were invited to enrol in a longitudinal QoL follow-up study. Patients were interviewed at hospital discharge, 30, 90 and 180 days, using validated physical and mental health assessment questionnaires (Short-Form-36, EuroQol-5-Dimension).

Patterns of sperm swimming behaviour depend on male mating tactic and spawning environment in chinook salmon.

Many species exhibit alternative mating tactics (ARTs), with larger socially dominant males competing for females and smaller males adopting "sneaker" strategies to exploit fertilisation opportunities without competition or courtship. Females typically prefer larger socially dominant males, but their ability to manipulate mating or fertilisation outcomes is largely unknown. Here, using chinook salmon Oncorhynchus tshawytscha, we examined whether the female's ovarian fluid (OF) differentially influences the temporal patterns of sperm swimming traits in ejaculates from non-preferred sneaker ('parr') and preferred (dominant) males.

Effect of intravenous vitamin C on arterial blood gas analyser and Accu-Chek point-of-care glucose monitoring in critically ill patients.

Intravenous vitamin C is known to interfere with some point-of-care blood glucose meters. We aimed to determine the concentrations at which ascorbate interferes with glucose concentrations measured using a point-of-care blood glucose meter. We also compared the point-of-care meter and an arterial blood gas (ABG) analyser in the intensive care unit with laboratory glucose monitoring in septic patients receiving intravenous vitamin C infusions.

Critically ill septic patients have elevated oxidative stress biomarkers: lack of attenuation by parenteral vitamin C.

Patients with septic shock are under an intense inflammatory burden, which is closely associated with increased oxidative stress and depletion of antioxidants such as vitamin C. We hypothesized that patients with septic shock would present with elevated oxidative stress (assessed as F-isoprostanes) and that administration of parenteral vitamin C to these patients would attenuate F-isoprostane concentrations. We recruited 40 critically ill patients with septic shock into a randomized placebo-controlled trial and assessed the effect of short-term (4-day) parenteral vitamin C administration (100 mg/kg/d) on 8-isoprostane F concentrations, which were measured using enzyme-linked immunosorbent assays.

Intravenous vitamin C administration to patients with septic shock: a pilot randomised controlled trial.

Background: Intravenous vitamin C administration in septic shock may have a sparing effect on vasopressor requirements, and vitamin C's enzyme cofactor functions provide a mechanistic rationale. Our study aimed to determine the effect of intravenous vitamin C administration on vasopressor requirements and other outcomes in patients with septic shock.

Methods: This was a double-blind, randomised placebo-controlled trial in 40 patients with septic shock who were randomised (1:1) to receive intravenous vitamin C (at a dose of 25 mg/kg of body weight every 6 h) or placebo (intravenous 5% dextrose) for up to 96 h, or until death or discharge.

Circulating protein carbonyls are specifically elevated in critically ill patients with pneumonia relative to other sources of sepsis.

Background: Septic shock is a life-threatening dysregulated response to severe infection and is associated with elevated oxidative stress. We aimed to assess protein carbonyls in critically ill patients with different sources of sepsis and determine the effect of vitamin C intervention on protein carbonyl concentrations.

Methods: Critically ill patients with septic shock (n = 40) were recruited, and sources of sepsis and ICU severity scores were recorded.

Neutrophils Isolated from Septic Patients Exhibit Elevated Uptake of Vitamin C and Normal Intracellular Concentrations despite a Low Vitamin C Milieu.

Vitamin C (ascorbate) plays an important role in neutrophil function and is accumulated by the cells either directly via vitamin C transporters (SVCT) or indirectly following oxidation to dehydroascorbic acid. Septic patients are known to have significantly depleted plasma ascorbate status, but little is known about the ascorbate content of their circulating cells. Therefore, we assessed the ascorbate concentrations of plasma, leukocytes and erythrocytes from septic patients and compared these to healthy controls.

Ovarian fluid proteome variation associates with sperm swimming speed in an externally fertilizing fish.

Sperm velocity is a key trait that predicts the outcome of sperm competition. By promoting or impeding sperm velocity, females can control fertilization via postcopulatory cryptic female choice. In Chinook salmon, ovarian fluid (OF), which surrounds the ova, mediates sperm velocity according to male and female identity, biasing the outcome of sperm competition towards males with faster sperm.

Circulating myeloperoxidase is elevated in septic shock and is associated with systemic organ failure and mortality in critically ill patients.

Background: Neutrophils are elevated in critically ill patients during the systemic inflammatory response to trauma and sepsis. The neutrophil-derived enzyme myeloperoxidase generates reactive oxygen species which can react with host tissue resulting in cell damage and dysfunction. Thus, elevated myeloperoxidase in the circulation may be associated with adverse patient outcomes.

Hypovitaminosis C and vitamin C deficiency in critically ill patients despite recommended enteral and parenteral intakes.

Background: Vitamin C is an essential water-soluble nutrient which cannot be synthesised or stored by humans. It is a potent antioxidant with anti-inflammatory and immune-supportive roles. Previous research has indicated that vitamin C levels are depleted in critically ill patients.

Sperm competition risk drives rapid ejaculate adjustments mediated by seminal fluid.

In many species, males can make rapid adjustments to ejaculate performance in response to sperm competition risk; however, the mechanisms behind these changes are not understood. Here, we manipulate male social status in an externally fertilising fish, chinook salmon (), and find that in less than 48 hr, males can upregulate sperm velocity when faced with an increased risk of sperm competition. Using a series of sperm manipulation and competition experiments, we show that rapid changes in sperm velocity are mediated by seminal fluid and the effect of seminal fluid on sperm velocity directly impacts paternity share and therefore reproductive success.

Cryptic female choice enhances fertilization success and embryo survival in chinook salmon.

In this study, we investigated two potentially important intersexual postcopulatory gametic interactions in a population of chinook salmon (Oncorhynchus tshawytscha): (i) the effect of female ovarian fluid (OF) on the behaviour of spermatozoa during fertilization and (ii) the effects of multilocus heterozygosity (MLH) (as an index of male quality) and female-male genetic relatedness on sperm behaviour and male fertilization success when there is sperm competition in the presence of that OF. To do this, we conducted a series of in vitro competitive fertilization experiments and found that, when ejaculates from two males are competing for access to a single female's unfertilized eggs, fertilization success was significantly biased towards the male whose sperm swam fastest in the female's OF. Embryo survival--a measure of fitness--was also positively correlated with both sperm swimming speed in OF and male MLH, providing novel evidence that cryptic female choice is adaptive for the female, enhancing the early survival of her offspring and potentially influencing her fitness.

Proteomic analysis of chinook salmon (Oncorhynchus tshawytscha) ovarian fluid.

The ovarian, or coelomic, fluid that is released with the egg mass of many fishes is increasingly found to play an important role in several biological processes crucial for reproductive success. These include maintenance of oocyte fertility and developmental competence, prolonging of sperm motility, and enhancing sperm swimming speed. Here we examined if and how the proteome of chinook salmon (Oncorhynchus tshawytscha) ovarian fluid varied among females and then sought to examine the composition of this fluid.

Delineating the roles of males and females in sperm competition.

Disentangling the relative roles of males, females and their interactive effects on competitive fertilization success remains a challenge in sperm competition. In this study, we apply a novel experimental framework to an ideally suited externally fertilizing model system in order to delineate these roles. We focus on the chinook salmon, Oncorhynchus tshawytscha, a species in which ovarian fluid (OF) has been implicated as a potential arbiter of cryptic female choice for genetically compatible mates.

Chemical composition of seminal and ovarian fluids of chinook salmon (Oncorhynchus tshawytscha) and their effects on sperm motility traits.

The relationships between the compositions of ovarian, seminal fluids and sperm function are not well known in teleostean fish species. The objective of the present study was to determine the concentration of the major inorganic ions (Na(+), K(+), Ca(2+), Mg, Cl(-)), osmolality, and pH of ovarian and seminal fluid of sexually mature chinook salmon (Oncorhynchus tshawytscha), and to determine if the composition of these fluids influences sperm motility traits (swimming speed, duration of forward mobility, swimming path trajectory, and percent motility). Cation concentrations and osmolality were significantly different in the two fluids.