Aloidendron barberae

Aloidendron is a very small genus of seven tree aloes in the family Asphodelaceae, described as recently as 2013, ranging from South Africa to Mozambique, with a large disjunction to Somalia, Yemen and Saudi Arabia. Aloidendron barberae is recorded from South Africa, Swaziland and southern Mozambique. However, the records for Mozambique are queried here and it is suggested that these actually relate to its closest relative, Aloidendron tongaense, a smaller tree only 4-8 m tall, which may be endemic to Mozambique. Aloidendron barberae is the largest alooid, growing to 20 m tall and is copiously dichotomously branched. Its taxonomic and nomenclatural history are outlined. Its habitat, natural distribution, ecology and cultivation are discussed, accompanied by a full description and reproduction of a specially commissioned watercolour painting

Dysregulation of glucocorticoid metabolism in murine obesity: comparable effects of leptin resistance and deficiency

In obese humans, metabolism of glucocorticoids by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) and A-ring reduction (by 5α- and 5β-reductases) is dysregulated in a tissue specific manner. These changes have been recapitulated in leptin resistant obese Zucker rats but were not observed in high-fat fed Wistar rats. Recent data from mouse models suggest that such discrepancies may reflect differences in leptin signalling. We therefore compared glucocorticoid metabolism in murine models of leptin deficiency and resistance. Male ob/ob and db/db mice and their respective littermate controls (n=10–12/group) were studied at the age of 12 weeks. Enzyme activities and mRNA expression were quantified in snap-frozen tissues. The patterns of altered pathways of steroid metabolism in obesity were similar in ob/ob and db/db mice. In liver, 5β-reductase activity and mRNA were increased and 11β-HSD1 decreased in obese mice, whereas 5α-reductase 1 (5αR1) mRNA was not altered. In visceral adipose depots, 5β-reductase was not expressed, 11β-HSD1 activity was increased and 5αR1 mRNA was not altered in obesity. By contrast, in subcutaneous adipose tissue 11β-HSD1 and 5αR1 mRNA were decreased. Systematic differences were not found between ob/ob and db/db murine models of obesity, suggesting that variations in leptin signalling through the short splice variant of the Ob receptor do not contribute to dysregulation of glucocorticoid metabolism

Materials for phantoms for terahertz pulsed imaging

Phantoms are commonly used in medical imaging for quality assurance, calibration, research and teaching. They may include test patterns or simulations of organs, but in either case a tissue substitute medium is an important component of the phantom. The aim of this work was to identify materials suitable for use as tissue substitutes for the relatively new medical imaging modality terahertz pulsed imaging. Samples of different concentrations of the candidate materials TX151 and napthol green dye were prepared, and measurements made of the frequency-dependent absorption coefficient (0.5 to 1.5 THz) and refractive index (0.5 to 1.0 THz). These results were compared qualitatively with measurements made in a similar way on samples of excised human tissue (skin, adipose tissue and striated muscle). Both materials would be suitable for phantoms where the dominant mechanism to be simulated is absorption (similar to ∼100 cm(-1) at 1 THz) and where simulation of the strength of reflections from boundaries is not important; for example, test patterns for spatial resolution measurements. Only TX151 had a frequency-dependent refractive index close to that of tissue, and could therefore be used to simulate the layered structure of skin, the complexity of microvasculature or to investigate frequency-dependent interference effects that have been noted in terahertz images

<i>Kalanchoe beharensis</i>. Crassulaceae: Kalanchooideae

Kalanchoe beharensis is one of the largest species of the diverse genus, reaching a height of about 3 m, one of only a few that can be regarded as truly arborescent. The species is discussed in detail in terms of its history, taxonomy, relationships, distribution, habitat, variability and cultivation. It is described in full and illustrated with a water-colour painting and colour photos. This species is endemic to and fairly widespread in western, central and eastern Madagascar including Behara after which it is named. It has been introduced to several mild-climate parts of the world and is now widespread in cultivation

Human gut bifidobacteria inhibit the growth of the opportunistic fungal pathogen Candida albicans

Open Access via the OUP Agreement Funding: Initial studies were funded from a Wellcome Institutional Strategic Support Fund (ISSF) Seed Corn Award [105625/Z/14/Z]. Thereafter, the research was funded by the Scottish Government’s Rural and Environment Science and Analytical Services (RESAS) division. AJPB was supported by programme grants from the UK Medical Research Council (MR/M026663/1; MR/M026663/2) and by the Medical Research Council Centre for Medical Mycology (MR/N006364/1; MR/N006364/2). Acknowledgements: We thank Dr Donna M. MacCallum for critical reading of the manuscript, the Centre for Genome-Enabled Biology and Medicine at the University of Aberdeen for carrying out the 16S rRNA gene sequencing, and Donna Henderson for GC analysis of bacterial fermentation acids. The authors also acknowledge the support of the Maxwell computer cluster funded by the University of Aberdeen.Peer reviewedPublisher PD

Aloiampelos ciliaris var. ciliaris. Asphodelaceae: Alooideae

Aloiampelos ciliaris is the type of a new genus of just seven species separated from Aloe in 2013 to accommodate the scrambling South African aloes. The history, taxonomy, distribution, ecology, cytology and cultivation of this species are all discussed in detail. This species is unique for Southern Africa in having a hexaploid chromosome count of 2n=42. The leaf structure is also distinctive with an amplexicaul base bearing conspicuous white cilia. It is endemic to the Eastern Cape Province

Pivotal Roles for pH, Lactate, and Lactate-Utilizing Bacteria in the Stability of a Human Colonic Microbial Ecosystem.

Lactate can be produced by many gut bacteria, but in adults its accumulation in the colon is often an indicator of microbiota perturbation. Using continuous culture anaerobic fermentor systems, we found that lactate concentrations remained low in communities of human colonic bacteria maintained at pH 6.5, even when dl-lactate was infused at 10 or 20 mM. In contrast, lower pH (5.5) led to periodic lactate accumulation following lactate infusion in three fecal microbial communities examined. Lactate accumulation was concomitant with greatly reduced butyrate and propionate production and major shifts in microbiota composition, with Bacteroidetes and anaerobic Firmicutes being replaced by Actinobacteria, lactobacilli, and Proteobacteria Pure-culture experiments confirmed that Bacteroides and Firmicutes isolates were susceptible to growth inhibition by relevant concentrations of lactate and acetate, whereas the lactate-producer Bifidobacterium adolescentis was resistant. To investigate system behavior further, we used a mathematical model (microPop) based on 10 microbial functional groups. By incorporating differential growth inhibition, our model reproduced the chaotic behavior of the system, including the potential for lactate infusion both to promote and to rescue the perturbed system. The modeling revealed that system behavior is critically dependent on the proportion of the community able to convert lactate into butyrate or propionate. Communities with low numbers of lactate-utilizing bacteria are inherently less stable and more prone to lactate-induced perturbations. These findings can help us to understand the consequences of interindividual microbiota variation for dietary responses and microbiota changes associated with disease states.IMPORTANCE Lactate is formed by many species of colonic bacteria, and can accumulate to high levels in the colons of inflammatory bowel disease subjects. Conversely, in healthy colons lactate is metabolized by lactate-utilizing species to the short-chain fatty acids butyrate and propionate, which are beneficial for the host. Here, we investigated the impact of continuous lactate infusions (up to 20 mM) at two pH values (6.5 and 5.5) on human colonic microbiota responsiveness and metabolic outputs. At pH 5.5 in particular, lactate tended to accumulate in tandem with decreases in butyrate and propionate and with corresponding changes in microbial composition. Moreover, microbial communities with low numbers of lactate-utilizing bacteria were inherently less stable and therefore more prone to lactate-induced perturbations. These investigations provide clear evidence of the important role these lactate utilizers may play in health maintenance. These should therefore be considered as potential new therapeutic probiotics to combat microbiota perturbations

Supporting doctors’ well-being and resilience during COVID-19 : a framework for rapid and rigorous intervention development

Authors thank the Chief Scientist Office, Scotland for supporting the research.This paper aims to outline the development of a theoretically informed and evidence-based intervention strategy to underpin interventions to support the well-being of doctors during COVID-19 and beyond; delineate new ways of working were employed to ensure a rapid and rigorous process of intervention development and present the resulting novel framework for intervention development. The research comprised four workstreams: literature review (WS1), qualitative study (WS2), intervention development and implementation (WS3) and evaluation (WS4). Due to time constraints, we employed a parallel design for WS1–3 with the findings of WS1–2 informing WS3 on a continual basis. WS3 was underpinned by the Behaviour Change Wheel. We recruited expert panels to assist with intervention development. We reflected on decisions taken to facilitate the rapid yet rigorous process of intervention development. The empirical output was a theoretically informed and evidence-based intervention strategy to underpin interventions to support doctors' well-being during COVID-19 and beyond. The methodological output was a novel framework that facilitates rapid and rigorous development of interventions. The intervention strategy provides a foundation for development and evaluation of tailored interventions to support doctors' well-being. The novel framework provides guidance for the development of interventions where the situation demands a rapid yet rigorous development process.Publisher PDFPeer reviewe

Exclusive enteral nutrition mediates gut microbial and metabolic changes that are associated with remission in children with Crohn’s disease

GD and AWW receive core funding support from the Scottish Government’s Rural and Environmental Science and Analytical Services (RESAS) Division. JW was funded by the Wellcome Trust [Grant No. 098051]. JVL is funded by MRC New Investigator Grant (MR/P002536/1) and ERC Starting Grant (715662). JK is funded by NIHR: II-OL-1116-10027, NIH: R01-CA204403-01A1, Horizon H2020: ITN GROWTH. Imperial Biomedical Research Centre, SAGES research grant. Infrastructure support for this research was provided by the NIHR Imperial biomedical Research Centre (BRC). Microbiota analyses were carried out using the Maxwell computer cluster at the University of Aberdeen. We thank the Illumina MiSeq team at the Wellcome Sanger Institute for their assistance. This work was partially described in the Ph.D. thesis of KD (Retrieved 2020, Pediatric inflammatory bowel disease Monitoring, nutrition and surgery, https://pure.uva.nl/ws/files/23176012/Thesis_complete_.pdf).Peer reviewedPublisher PD

11β-HSD1 suppresses cardiac fibroblast CXCL2, CXCL5 and neutrophil recruitment to the heart post MI

We have previously demonstrated that neutrophil recruitment to the heart following myocardial infarction (MI) is enhanced in mice lacking 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) that regenerates active glucocorticoid within cells from intrinsically inert metabolites. The present study aimed to identify the mechanism of regulation. In a mouse model of MI, neutrophil mobilization to blood and recruitment to the heart were higher in 11β-HSD1-deficient (Hsd11b1(-)(/)(-) ) relative to wild-type (WT) mice, despite similar initial injury and circulating glucocorticoid. In bone marrow chimeric mice, neutrophil mobilization was increased when 11β-HSD1 was absent from host cells, but not when absent from donor bone marrow-derived cells. Consistent with a role for 11β-HSD1 in 'host' myocardium, gene expression of a subset of neutrophil chemoattractants, including the chemokines Cxcl2 and Cxcl5, was selectively increased in the myocardium of Hsd11b1(-)(/)(-) mice relative to WT. SM22α-Cre directed disruption of Hsd11b1 in smooth muscle and cardiomyocytes had no effect on neutrophil recruitment. Expression of Cxcl2 and Cxcl5 was elevated in fibroblast fractions isolated from hearts of Hsd11b1(-)(/)(-) mice post MI and provision of either corticosterone or of the 11β-HSD1 substrate, 11-dehydrocorticosterone, to cultured murine cardiac fibroblasts suppressed IL-1α-induced expression of Cxcl2 and Cxcl5 These data identify suppression of CXCL2 and CXCL5 chemoattractant expression by 11β-HSD1 as a novel mechanism with potential for regulation of neutrophil recruitment to the injured myocardium, and cardiac fibroblasts as a key site for intracellular glucocorticoid regeneration during acute inflammation following myocardial injury