Sphingosine-1-phosphate promotes osteogenesis by stimulating osteoblast growth and neovascularization in a vascular endothelial growth factor-dependent manner.

Sphingosine-1-phosphate (S1P) plays multiple roles in bone metabolism and regeneration. Here, we have identified a novel S1P-regulated osteoanabolic mechanism functionally connecting osteoblasts (OBs) to the highly specialized bone vasculature. We demonstrate that S1P/S1PR3 signaling in OBs stimulates vascular endothelial growth factor a (VEGFa) expression and secretion to promote bone growth in an autocrine and boost osteogenic H-type differentiation of bone marrow endothelial cells in a paracrine manner. VEGFa-neutralizing antibodies and VEGF receptor inhibition by axitinib abrogated OB growth in vitro and bone formation in male C57BL/6J in vivo following S1P stimulation and S1P lyase inhibition, respectively. Pharmacological S1PR3 inhibition and genetic S1PR3 deficiency suppressed VEGFa production, OB growth in vitro, and inhibited H-type angiogenesis and bone growth in male mice in vivo. Together with previous work on the osteoanabolic functions of S1PR2 and S1PR3, our data suggest that S1P-dependent bone regeneration employs several nonredundant positive feedback loops between OBs and the bone vasculature. The identification of this yet unappreciated aspect of osteoanabolic S1P signaling may have implications for regular bone homeostasis as well as diseases where the bone microvasculature is affected such as age-related osteopenia and posttraumatic bone regeneration.

Sphingosine-1-phosphate (S1P) is a signaling lipid that regulates bone growth and regeneration. In the present study, a novel regenerative mechanism was connected to S1P signaling within the bone. Activation of its receptor S1PR3 in bone-forming osteoblasts led to secretion of vascular endothelial growth factor a (VEGFa), the most potent vessel-stimulating factor. This stimulated the development of specialized vessels of the bone marrow, the H-type vessels, that supported overall bone regeneration. These findings foster our understanding of regular bone metabolism and suggest that S1P-based drugs may help treat diseases such as age-related osteopenia and posttraumatic bone regeneration, conditions crucially dependent on functional bone microvasculature.

Sphingosine-1-phosphate suppresses GLUT activity through PP2A and counteracts hyperglycemia in diabetic red blood cells.

Red blood cells (RBC) are the major carriers of sphingosine-1-phosphate (S1P) in blood. Here we show that variations in RBC S1P content achieved by altering S1P synthesis and transport by genetic and pharmacological means regulate glucose uptake and metabolic flux. This is due to S1P-mediated activation of the catalytic protein phosphatase 2 (PP2A) subunit leading to reduction of cell-surface glucose transporters (GLUTs). The mechanism dynamically responds to metabolic cues from the environment by increasing S1P synthesis, enhancing PP2A activity, reducing GLUT phosphorylation and localization, and diminishing glucose uptake in RBC from diabetic mice and humans. Functionally, it protects RBC against lipid peroxidation in hyperglycemia and diabetes by activating the pentose phosphate pathway. Proof of concept is provided by the resistance of mice lacking the S1P exporter MFSD2B to diabetes-induced HbA1c elevation and thiobarbituric acid reactive substances (TBARS) generation in diabetic RBC. This mechanism responds to pharmacological S1P analogues such as fingolimod and may be functional in other insulin-independent tissues making it a promising therapeutic target.

Chromosomal rearrangement in the 22q11.2 region: a critical locus for sociability and attentional skills.

Rearrangements of 22q11.2 region, most often deletions and duplications, are responsible for multiple congenital disorders. These rearrangements are involved in syndromes that share some phenotypic similarities. To date, 22q11.2 triplication remains very rare, with few cases described in the literature. Here, we report for the first time the clinical, neurocognitive, social cognition and psychiatric properties of a 6-year-old child with 22q11.2 triplication, in comparison with a patient with 22q11.2 duplication and 16 cases of patients with 22q11.2 deletion. Chromosomal region 22q11.2 seems to be a critical locus for sociability and attentional skills and rearrangements could be interpreted as a predisposing factor for the development of psychotic symptoms (22q11.2 deletion), a protective factor (22q11.2 duplication) or a tendency factor for hypersociability (22q11.2 triplication).

Characterisation of the effect of day length, and associated differences in dietary intake, on the gut microbiota of Soay sheep.

Differences in the rumen bacterial community have been previously reported for Soay sheep housed under different day length conditions. This study extends this previous investigation to other organs of the digestive tract, as well as the analysis of ciliated protozoa and anaerobic fungi. The detectable concentrations of ciliated protozoa and anaerobic fungi decreased with increased day length in both the rumen and large colon, unlike those of bacteria where no effect was observed. Conversely, bacterial community composition was affected by day length in both the rumen and large colon, but the community composition of the detectable ciliated protozoa and anaerobic fungi was not affected. Day length-associated differences in the bacterial community composition extended to all of the organs examined, with the exception of the duodenum and the jejunum. It is proposed that differences in rumen fill and ruminal 'by-pass' nutrients together with endocrinological changes cause the observed effects of day length on the different gut microbial communities.

New barrier attire regulations in the operating room: A mandate without basis?

BACKGROUND: Recent AHRQ/Joint Commission guidelines mandate additional barrier attire for all operating room personnel to target infection. The scientific basis for this is unclear. STUDY DESIGN: Patients undergoing abdominal surgery at our institution were identified from institutional NSQIP database before and after March 2016, when guidelines were implemented. Patient-level variables were compared for the pre- and post-implementation groups. Multivariable regression evaluated associations between implementation and surgical site infection (SSI) and other outcomes. RESULTS: 1122 patients (including 60.9% laparoscopic and 16.4% bowel resection procedures) were included. There were 607 patients post-implementation and 515 pre-implementation; cohorts were similar in risk factors for SSI. Fifty-seven patients developed SSI. On multivariable analysis, laparoscopy, bowel resection and operating duration, but not barrier attire, were associated with SSI. Implementation of attire did not significantly impact SSI (p = 0.4), hospital readmission (p = 0.4), or reoperation (p = 0.9). CONCLUSIONS: These data question the rationale for the new more stringent operating room attire guidelines which burden hospitals with additional cost, time and resources, and could detract efforts to target important factors that really influence outcomes.

Living alone but eating together: Exploring lunch clubs as a dining out experience.

Dining out is most often associated with pleasure and gratification, principally since it presents opportunities for sociability. However, access to dining out experiences is influenced by multiple factors, including age. Little is known about the dining out habits of older people. In particular, the food practices of those living alone in the community is under-researched compared to those in hospital or residential care. This study explores the perceptions and preferences of ten older people towards domestic and communal meals in South East Scotland. Qualitative data were generated from 5-day food diaries and in-depth interviews with individuals who lived alone and attended a community-based senior citizen's lunch club. Data were coded and thematically analysed using a symbolic interactionist perspective. A number of key themes were identified, including the meaning of mealtimes. It was found that most participants ate the majority of their meals at home alone. Despite this, dining alone was not necessarily experienced as 'lonely'. Participants reported that dining out at the lunch club was a pleasurable experience given the social interaction and the separation of consumption from food work. Moreover, due to restricted mobility and limited access to transport, the lunch club was viewed by participants as one of the few places that they could go to dine out.

It is elemental: soil nutrient stoichiometry drives bacterial diversity.

It is well established that resource quantity and elemental stoichiometry play major roles in shaping below and aboveground plant biodiversity, but their importance for shaping microbial diversity in soil remains unclear. Here, we used statistical modeling on a regional database covering 179 locations and six ecosystem types across Scotland to evaluate the roles of total carbon (C), nitrogen (N) and phosphorus (P) availabilities and ratios, together with land use, climate and biotic and abiotic factors, in determining regional scale patterns of soil bacterial diversity. We found that bacterial diversity and composition were primarily driven by variation in soil resource stoichiometry (total C:N:P ratios), itself linked to different land uses, and secondarily driven by other important biodiversity drivers such as climate, soil spatial heterogeneity, soil pH, root influence (plant-soil microbe interactions) and microbial biomass (soil microbe-microbe interactions). In aggregate, these findings provide evidence that nutrient stoichiometry is a strong predictor of bacterial diversity and composition at a regional scale.

Loss of microbial diversity in soils is coincident with reductions in some specialized functions.

Loss of microbial diversity is considered a major threat because of its importance for ecosystem functions, but there is a lack of conclusive evidence that diversity itself is reduced under anthropogenic stress, and about the consequences of diversity loss. Heavy metals are one of the largest, widespread pollutant types globally, and these represent a significant environmental stressor for terrestrial microbial communities. Using combined metagenomics and functional assays, we show that the compositional and functional response of microbial communities to long-term heavy metal stress results in a significant loss of diversity. Our results indicate that even at a moderate loss of diversity, some key specialized functions (carried out by specific groups) may be compromised. Together with previous work, our data suggest disproportionate impact of contamination on microbes that carry out specialized, but essential, ecosystem functions. Based on these findings, we propose a conceptual framework to explicitly consider diversity of functions and microbial functional groups to test the relationship between biodiversity and soil functions.

Multiplex T-RFLP allows for increased target number and specificity: detection of Salmonella enterica and six species of Listeria in a single test.

A multiplex T-RFLP test was developed to detect and identify Salmonella enterica and all six species of Listeria inoculated into milk at minimal levels. Extensive in silico analysis was used to design a fifteen-primer, six-amplimer methodology and in vitro application showed target organism DNA, when amplified individually, yielded the predicted terminal restriction fragments (TRFs) following digestion. Non-target organisms were either not-amplified or yielded TRFs which did not interfere with target identification. Multiple target DNA analysis gave over 86% detection of total TRFs predicted, and this was improved to over 90% detection of total TRFs predicted when only two target DNA extracts were combined analysed. Co-inoculation of milk with five strains each of the target species of S. enterica and L. monocytogenes, along with five strains of the non-target species E. coli was followed by enrichment in SEL medium for M-TRFLP analysis. This allowed for detection of both target species in all samples, with detection of one S. enterica and two Listeria TRFs in all cases, and detection of a second S. enterica TRF in 91% of cases. This was from an initial inoculum of <5 cfu per 25 ml milk with a background of competing E. coli present, and gave a result from sampling of under 20 hours. The ability to increase target species number without loss of sensitivity means that extensive screening can be performed at reduced cost due to a reduction in the number of tests required.

Differences between human subjects in the composition of the faecal bacterial community and faecal metabolism of linoleic acid.

Conjugated linoleic acid (CLA) is formed from linoleic acid (LA; cis-9,cis-12-18:2) by intestinal bacteria. Different CLA isomers have different implications for human health. The aim of this study was to investigate LA metabolism and the CLA isomers formed in two individuals (V1 and V2) with different faecal metabolic characteristics, and to compare fatty acid metabolism with the microbial community composition. LA incubated with faecal samples was metabolized at similar rates with both subjects, but the products were different. LA was metabolized extensively to stearic acid (SA; 18:0) in V1, with minor accumulation of CLA and more rapid accumulation of vaccenic acid (VA; trans-11-18:1). CLA accumulation at 4 h was almost tenfold higher with V2, and little SA was formed. At least 12 different isomers of CLA were produced from LA by the colonic bacteria from the two individuals. The predominant (>75%) CLA isomer in V1 was rumenic acid (RA; cis-9,trans-11-18:2), whereas the concentrations of RA and trans-10,cis-12-18:2 were similar with V2. Propionate and butyrate proportions in short-chain fatty acids were higher in V1. A 16S rRNA clone library from V1 contained mainly Bacteroidetes (54% of clones), whereas Firmicutes (66% of clones) predominated in V2. Both samples were devoid of bacteria related to Clostridium proteoclasticum, the only gut bacterium known to metabolize VA to SA. Thus, the CLA formed in the intestine of different individuals may differ according to their resident microbiota, with possibly important implications with respect to gut health.

Horizontal gene transfer from Bacteria to rumen Ciliates indicates adaptation to their anaerobic, carbohydrates-rich environment.

BACKGROUND: The horizontal transfer of expressed genes from Bacteria into Ciliates which live in close contact with each other in the rumen (the foregut of ruminants) was studied using ciliate Expressed Sequence Tags (ESTs). More than 4000 ESTs were sequenced from representatives of the two major groups of rumen Cilates: the order Entodiniomorphida (Entodinium simplex, Entodinium caudatum, Eudiplodinium maggii, Metadinium medium, Diploplastron affine, Polyplastron multivesiculatum and Epidinium ecaudatum) and the order Vestibuliferida, previously called Holotricha (Isotricha prostoma, Isotricha intestinalis and Dasytricha ruminantium). RESULTS: A comparison of the sequences with the completely sequenced genomes of Eukaryotes and Prokaryotes, followed by large-scale construction and analysis of phylogenies, identified 148 ciliate genes that specifically cluster with genes from the Bacteria and Archaea. The phylogenetic clustering with bacterial genes, coupled with the absence of close relatives of these genes in the Ciliate Tetrahymena thermophila, indicates that they have been acquired via Horizontal Gene Transfer (HGT) after the colonization of the gut by the rumen Ciliates. CONCLUSION: Among the HGT candidates, we found an over-representation (>75%) of genes involved in metabolism, specifically in the catabolism of complex carbohydrates, a rich food source in the rumen. We propose that the acquisition of these genes has greatly facilitated the Ciliates' colonization of the rumen providing evidence for the role of HGT in the adaptation to new niches.

Multiplex-terminal restriction fragment length polymorphism.

A novel method called "multiplex-terminal restriction fragment length polymorphism (M-TRFLP)" has been recently developed which can be used for simultaneous analysis of the community composition of two or more microbial taxa (up to four). This method can also be used for microbial diagnostic purposes. For M-TRFLP analysis, primers specific to different target genes are used for multiplex-PCR, with one primer for each target being labeled with a unique fluorescent dye at its 5' end. Restriction digestion of the amplified products followed by fragment size analysis on a DNA sequencer produces profiles for targeted genes, which can be distinguished from each other by the color of the terminal fragments imparted by the unique fluorescent dye used for primer labeling. In contrast to current protocols, M-TRFLP allows multiple communities or multiple targets (genes) data to be obtained in just one reaction and therefore saves time, cost and labor. This protocol can be completed in 5-8 h.

Diagnosis of Partial Anomalous Pulmonary Venous Connection with Intact Interatrial Septum by Echocardiography.

This case illustrates the complementary use of transthoracic echocardiography and transesophageal echocardiography in the diagnosis of partial anomalous pulmonary venous connection. The transthoracic echocardiogram suggested the presence of anomalous pulmonary venous return by demonstrating right heart volume overload and evidence of an intact atrial septum. Transesophageal echocardiography was required to confirm these findings and provide a firm anatomic diagnosis before surgery. This case also emphasizes that a high degree of clinical suspicion for this condition should occur in situations in which apparent right heart volume overload is otherwise unexplained.