Extraction and Quantification of Bioactive Tyrian Purple Precursors: A Comparative and Validation Study from the Hypobranchial Gland of a Muricid Dicathais orbita

Muricidae are marine molluscs known for the production of Tyrian purple and bioactive precursor compounds. A validation study for the extraction and analysis of secondary metabolites found in the hypobranchial gland of the muricid Dicathais orbita is reported, using high performance liquid chromatography–mass spectrometry (HPLC-MS) with diode array detector (DAD). Quantification of the dominant secondary metabolites from D. orbita is described, followed by a comparison of solvent extraction procedures and stability studies. The intra- and inter-day relative standard deviation (RSD) for tyrindoxyl sulphate was 0.46% and 0.17%, respectively. The quantification was linear for standards murexine, 6-bromoisatin, and tyrindoxyl sulphate. The limits of detection were 0.03, 0.004, and 0.07 mg/mL, respectively, and the limits of quantification were 0.09, 0.01, and 0.22 mg/mL, respectively. The results showed that alcoholic solvents were better for extracting choline ester and indoxyl sulphate ultimate precursors, while chloroform was more suitable for the extraction of the intermediate precursors. Multivariate analysis revealed significant differences in extract composition according to the solvent used. Stability testing showed an increase of the oxidative compounds 6-bromoisatin and putative tyrindoxyl S-oxide sulphate in the ethanol extracts while more degradation products were seen in the chloroform extracts after months of cold storage. The validated method was found to be simple, reproducible, precise, and suitable for quantification of the secondary metabolites of muricid molluscs for dye precursor and nutraceutical quality control, as well as applications in marine chemical ecology

The relationship between hyperglycaemia on admission and patient outcome is modified by hyperlactatemia and diabetic status: a retrospective analysis of the eICU collaborative research database

Abstract Both blood glucose and lactate are well-known predictors of organ dysfunction and mortality in critically ill patients. Previous research has shown that concurrent adjustment for glucose and lactate modifies the relationship between these variables and patient outcomes, including blunting of the association between blood glucose and patient outcome. We aim to investigate the relationship between ICU admission blood glucose and hospital mortality while accounting for lactate and diabetic status. Across 43,250 ICU admissions, weighted to account for missing data, we assessed the predictive ability of several logistic regression and generalised additive models that included blood glucose, blood lactate and diabetic status. We found that inclusion of blood glucose marginally improved predictive performance in all patients: AUC-ROC 0.665 versus 0.659 (p = 0.005), with a greater degree of improvement seen in non-diabetics: AUC-ROC 0.675 versus 0.663 (p < 0.001). Inspection of the estimated risk profiles revealed the standard U-shaped risk profile for blood glucose was only present in non-diabetic patients after controlling for blood lactate levels. Future research should aim to utilise observational data to estimate whether interventions such as insulin further modify this effect, with the goal of informing future RCTs of interventions targeting glycaemic control in the ICU

Recreational fishing for Abalone in Western Australia in 2021/22: estimates of participation, effort and catch.

The Western Australian Recreational Abalone Fishery (RAF) operates in shallow coastal waters along the metropolitan, south-west and south coasts. This hand collection fishery targets three species of abalone. Roe’s Abalone (Haliotis roei) inhabit nearshore reef complexes and are therefore generally collected while wading from the shore in accessible areas. This species is taken from the metropolitan, south-west and south coast regions. Greenlip Abalone (H. laevigata) and Brownlip Abalone (H. conicopora) are collected while wading (including snorkelling) and diving (using compressed air) and occur predominantly in the south coast region. Recreational fishing for all abalone species is licensed and highly regulated, especially in the Western Zone (includes the Perth Metropolitan Roe’s Abalone Fishery) where fishing is only permitted for a 1-hour period on four days per year. Recreational abalone fishers are required to hold a licence, and this was used as a sampling frame to select fishers for a phone-recall survey to generate estimates of participation, fishing effort and retained catch (by numbers and weight) for 2021/22. These are the first statewide estimates since intermittent phone-diary surveys in the mid-2000’s. Participation in the RAF (all three species) by licensed fishers (abalone licence holders aged five years and older) in 2021/22 (1 April 2021 – 31 March 2022) was 12,700 fishers (95% CI 12,391 – 13,008; 74.8% of licence holders). The total fishing effort (all three methods) for abalone fishing (all species) in 2021/22 was 48,860 days fished (95% CI 46,186 – 51,534); of which 94.4% or 46,111 (43,554 – 48,667) was by wading and 5.6% or 2,749 (1,846 – 3,652) by diving. The statewide harvest of Roe’s Abalone in 2021/22 was 48.0 t whole weight (ww) (95% CI 45.6 – 50.4); of which 99.6% or 47.8 t ww (45.4 – 50.2) was caught by wading and 0.4% or 0.2 t ww (0.1 – 0.4) by diving. The majority of this catch occurred in the Metro (46.9%) and South-West (34.6%) regions. The statewide harvest of Greenlip Abalone was 4.0 t meat weight (mw) (95% CI 3.3 – 4.7); while Brownlip Abalone was 1.5 t mw (95% CI 0.9 – 2.1), with the majority of these catches obtained by wading. A range of social and attitudinal information was also collected to inform future strategies for safety, communication and engagement with fishers. In terms of safety, 92.8% of fishers considered the weather and ocean conditions before going fishing and 68% of abalone licence holders could swim more than 200 metres (m) in a standard 25m swimming pool. Although 77.2% of abalone fishers spoke English at home, Mandarin (6.2%) and languages from other parts of Asia (9.2%) were also common. The majority of abalone fishers who fished were very satisfied (55.7%) or quite satisfied (29.6%) with this activity. This statewide phone-recall survey of the RAF will complement annual on-site monitoring within the Perth Metropolitan Roe’s Abalone Fishery, as well as provide robust estimates for use in stock assessments