Assessment, treatment and prevention of vitamin D deficiency.

Vitamin D deficiency is prevalent among various groups in the UK, and can result from insufficient sunlight exposure and dietary intake. There is a population-wide recommendation of 10 micrograms (400 international units) of vitamin D per day, with a daily supplement advised. However, supplement use is often suboptimal, compounding the risk of deficiency. Long-term vitamin D deficiency can cause rickets in children and osteomalacia or osteoporosis in adults. Therefore, it is important that nurses recognise which groups are at increased risk of vitamin D deficiency and understand how to assess people's vitamin D status. Nurses also need to be able to support the prevention and treatment of low vitamin D levels, which typically involves supplementation and lifestyle changes.

Fuligopyrones from the Fruiting Bodies of Myxomycete Fuligo septica Offer Short-Term Protection from Abiotic Stress Induced by UV Radiation.

The myxomycete Fuligo septica, colloquially referred to as "dog vomit fungus", forms vibrant yellow fruiting bodies (aethalia) on wood chips during warm and humid conditions in spring. In 2018, ideal climatic conditions in Sydney, Australia, provided a rare opportunity to access abundant quantities of F. septica aethalia, which enabled the isolation, purification, structure elucidation, and biological screening of two avenalumamide pyrones, fuligopyrone (1) and fuligopyrone B (2). While 1 and 2 did not exhibit any appreciable biological activity, their significant UV absorption at 325 nm suggested they may be acting as transient sunscreens to help protect the fruiting mass from exposure to sunlight. In support of this hypothesis, exposing a solution of 2 to direct sunlight for 5 min resulted in rapid equilibration with a mixture of 2E,4Z-fuligopyrone B (10) and 2Z,4E-fuligopyrone B (11) photoisomers.

Esterase-Mediated Sustained Release of Peptide-Based Therapeutics from a Self-Assembled Injectable Hydrogel.

A synthetic strategy for conjugating small molecules and peptide-based therapeutics, via a cleavable ester bond, to a lipidated ß3-tripeptide is presented. The drug-loaded ß3-peptide was successfully co-assembled with a functionally inert lipidated ß3-tripeptide to form a hydrogel. Quantitative release of lactose from the hydrogel, by the action of serum esterases, is demonstrated over 28 days. The esterase-mediated sustained release of the bioactive brain-derived neurotrophic factor (BDNF) peptide mimics from the hydrogel resulted in increased neuronal survival and normal neuronal function of peripheral neurons. These studies define a versatile strategy for the facile synthesis and co-assembly of self-assembling ß3-peptide-based hydrogels with the ability to control drug release using endogenous esterases with potential in vivo applications for sustained localized drug delivery.

Characterisation and heterologous biosynthesis of burnettiene A, a new polyene-decalin polyketide from Aspergillus burnettii.

Chemical exploration of the recently described Australian fungus, Aspergillus burnettii, uncovered a new metabolite, burnettiene A. Here, we characterise the structure of burnettiene A as a polyene-decalin polyketide. Bioinformatic analysis of the genome of A. burnettii identified a putative biosynthetic gene cluster for burnettiene A (bue), consisting of eight genes and sharing similarity to the fusarielin gene cluster. Introduction of the reassembled bue gene cluster into Aspergillus nidulans for heterologous expression resulted in the production of burnettiene A under native promoters. Omission of bueE encoding a cytochrome P450 led to the production of preburnettiene A, confirming that BueE is responsible for catalysing the regiospecific multi-oxidation of terminal methyl groups to carboxylic acids. Similarly, bueF was shown to encode an ester-forming methyltransferase, with its omission resulting in the production of the tricarboxylic acid, preburnettiene B. Introduction of an additional copy of the transcription factor bueR under the regulation of the gpdA promoter significantly improved the heterologous production of the burnettienes. Burnettiene A displayed strong in vitro cytotoxicity against mouse myeloma NS-1 cells (MIC 0.8 µg mL-1).

Vitamin D in obesity.

PURPOSE OF REVIEW: Vitamin D is essential for bone health, and may also have important functions in immunity and other systems. Vitamin D deficiency is common, and testing and supplementation is increasing. Serum vitamin D is lower in obese people; it is important to understand the mechanism of this effect and whether it indicates clinically significant deficiency. RECENT FINDINGS: Vitamin D is fat soluble, and distributed into fat, muscle, liver, and serum. All of these compartments are increased in volume in obesity, so the lower vitamin D likely reflects a volumetric dilution effect and whole body stores of vitamin D may be adequate. Despite lower serum vitamin D, obese adults do not have higher bone turnover or lower bone mineral density. Patients undergoing bariatric surgery do have bone loss, and ensuring vitamin D sufficiency in these patients may help to attenuate bone loss. SUMMARY: Lower vitamin D in obese people is a consistent finding across age, ethnicity, and geography. This may not always reflect a clinical problem. Obese people need higher loading doses of vitamin D to achieve the same serum 25-hydroxyvitamin D as normal weight.