Deconvolving microbial and environmental controls on marine sedimentary pyrite sulfur isotope ratios.

Reconstructions of past environmental conditions and biological activity are often based on bulk stable isotope proxies, which are inherently open to multiple interpretations. This is particularly true of the sulfur isotopic composition of sedimentary pyrite (δ34Spyr), which is used to reconstruct ocean-atmosphere oxidation state and track the evolution of several microbial metabolic pathways. We present a microanalytical approach to deconvolving the multiple signals that influence δ34Spyr, yielding both the unambiguous determination of microbial isotopic fractionation (εmic) and new information about depositional conditions. We applied this approach to recent glacial-interglacial sediments, which feature over 70‰ variations in bulk δ34Spyr across these environmental transitions. Despite profound environmental change, εmic remained essentially invariant throughout this interval and the observed range in δ34Spyr was instead driven by climate-induced variations in sedimentation.

A general swimming response in exhausted obligate swimming fish.

Marine organisms normally swim at elevated speeds relative to cruising speeds only during strenuous activity, such as predation or escape. We measured swimming speeds of 29 ram ventilating sharks from 10 species and of three Atlantic bluefin tunas immediately after exhaustive exercise (fighting a capture by hook-and-line) and unexpectedly found all individuals exhibited a uniform mechanical response, with swimming speed initially two times higher than the cruising speeds reached approximately 6 h later. We hypothesized that elevated swimming behaviour is a means to increase energetic demand and drive the removal of lactate accumulated during capture via oxidation. To explore this hypothesis, we estimated the mechanical work that must have been spent by an animal to elevate its swim speed and then showed that the amount of lactate that could have been oxidized to fuel it comprises a significant portion of the amount of lactate normally observed in fishes after exhaustive exercise. An estimate for the full energetic cost of the catch-and-release event ensued.

Real-world treatment sequencing and survival in previously treated advanced renal cell carcinoma patients receiving nivolumab monotherapy: a UK retrospective cohort study.

BACKGROUND: The CheckMate 025 trial established nivolumab monotherapy as one of the standards of care in previously treated advanced or metastatic renal cell carcinoma (aRCC). However, supporting real-world data is lacking. This study investigated characteristics, treatment sequences and clinical outcomes of patients who received nivolumab monotherapy for previously treated aRCC in the UK. METHODS: This was a retrospective cohort study of aRCC patients treated with nivolumab at second line or later (2L +) at 4 UK oncology centres. Eligible patients commenced nivolumab (index date) between 01 March 2016 and 30 June 2018 (index period). Study data were extracted from medical records using an electronic case report form. Data cut-off (end of follow-up) was 31 May 2019. RESULTS: In total, 151 patients were included with median follow-up of 15.2 months. Mean age was 66.9 years, male preponderance (72.2%), and mostly Eastern Cooperative Oncology Group performance status grade 0-1 (71.5%). Amongst 112 patients with a known International Metastatic RCC Database Consortium score, distribution between favourable, intermediate, and poor risk categories was 20.5%, 53.6%, and 25.9% respectively. The majority of patients (n = 109; 72.2%) received nivolumab at 2L, and these patients had a median overall survival (OS) of 23.0 months [95% confidence interval: 17.2, not reached]. All patients who received nivolumab at 2L had received TKIs at 1L. Amongst the 42 patients (27.8%) who received nivolumab in third line or later (3L +) the median OS was 12.4 months [95% CI: 8.8, 23.2]. The most common reasons for nivolumab discontinuation were disease progression (2L: 61.2%; 3L: 68.8%) and adverse events (2L: 34.7%; 3L: 28.1%). CONCLUSION: This study provides real-world evidence on the characteristics, treatment sequences, and outcomes of aRCC patients who received 2L + nivolumab monotherapy in the UK. Nivolumab-specific survival outcomes were similar to those achieved in the CheckMate 025 trial.

The utilisation of vascular limb salvage services in the assessment and management of chronic limb-threatening ischaemia and diabetic foot ulceration: A systematic review.

Specialist vascular limb salvage services have gained prominence as a new model of care to help overcome barriers which exist in the management of patients with chronic limb-threatening ischaemia (CLTI) and/or diabetic foot ulceration (DFU). This systematic review aims to explore the nature of reported services, investigate their outcome in the management of CLTI/DFU, and assess the scope and quality of the evidence base to help make recommendations for future practice and research. A systematic search of MEDLINE, Embase, The Cochrane Library, Scopus and CINAHL, from 1st January 1995 to 18th January 2019, was performed. Specialist vascular limb salvage services were defined as those services conforming to the definition of "centres of excellence" within the 2019 Global Vascular Guidelines. A study protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42019123325). In total, 2260 articles were screened, with 12 articles (describing 11 services) included in a narrative synthesis. All services ran akin to the "toe-and-flow" model, with a number of services having additional core input from diabetology, microbiology, allied health professionals and/or internal/vascular medicine. Methodological weaknesses were identified within the design of the included articles and only one was deemed of high quality. The inception of services was associated with improved rates of major amputation; however, no significant changes in minor amputation or mortality rates were identified. Further research should adopt more a standardised study design and outcomes measures in order to improve the quality of evidence within the literature.

Analysis of cell-free fetal DNA for non-invasive prenatal diagnosis in a family with neonatal diabetes.

AIMS: An early genetic diagnosis of neonatal diabetes guides clinical management and results in improved treatment in ~ 40% of patients. In the offspring of individuals with neonatal diabetes, a prenatal diagnosis allows accurate estimation of the risk of developing diabetes and, eventually, the most appropriate treatment for the baby. In this study, we performed non-invasive prenatal genetic testing for a fetus at risk of inheriting a paternal KCNJ11 p.R201C mutation causing permanent neonatal diabetes. METHODS: A droplet digital polymerase chain reaction assay was used to detect the presence of the mutation in cell-free circulating DNA (cfDNA) extracted from maternal plasma at 12 and 16 weeks' gestation. RESULTS: The mutation was not detected in the cfDNA samples, suggesting that the fetus had not inherited the KCNJ11 mutation. The fetal DNA fraction was estimated at 6.2% and 10.7%, which is above the detection limit of the assay. The result was confirmed by Sanger sequencing after the baby's birth, confirming that the baby's risk of developing neonatal diabetes was reduced to that of the general population. CONCLUSIONS: We report the first case of non-invasive prenatal testing in a family with neonatal diabetes. A prenatal diagnosis in families at high risk of monogenic diabetes informs both prenatal and postnatal management. Although the clinical impact of this novel technology still needs to be assessed, its implementation in clinical practice (including cases at risk of inheriting mutations from the mother) will likely have a positive impact upon the clinical management of families affected by monogenic diabetes.

Prospective 12-month functional and vocational outcomes of hip arthroscopy for femoroacetabular impingement as part of an evidence-based hip pain rehabilitation pathway in an active military population.

BACKGROUND: Femoroacetabular impingement (FAI) is common with an estimated prevalence of 10-15% among young active individuals. The natural history of the disorder is progression to early osteoarthritis. Hip arthroscopy is recommended if conservative treatments fail; however, outcomes are unclear, particularly in highly active populations. AIM: To evaluate the functional and vocational outcome of hip arthroscopy, as part of an evidence-based rehabilitation hip pain pathway, for the treatment of FAI in an active military population. METHODS: All patients in the defence rehabilitation hip pain pathway, with a confirmed diagnosis of FAI who failed conservative treatment, were assessed prior to surgery and at 2, 6 and 12 months postsurgery. Outcome measures included the Visual Analogue Scale (VAS) for hip pain, Non-Arthritic Hip Score (NAHS) for function, and vocational assessments including functional activity assessment (FAA) and Joint Medical Employment Standard for military employability and deployability. RESULTS: 101 patients completed the study (mean age=33 years) (male:female:75:26) (Royal Navy/British Army/Royal Air Force: 13%/48%/39%). Outcomes demonstrated significant improvements with large effect size. Preoperative NAHS mean=62.9 (SD 16.4), 12-month postoperative NAHS mean=78.8 (18.3), mean improvement in NAHS=15.9 (95% CI 12.3 to 19.5, p<0.001). Preoperative VAS pain mean=51.3 (20.9), 12-month postoperative VAS pain=25.6 (24.5). Mean improvement 25.7 (95% CI 19.4 to 31.99, p<0.001). 73% of patients had a deployable medical category at 12 months postoperative. CONCLUSIONS: These data confirm that hip arthroscopy as part of a structured evidence-based multidisciplinary care pathway produces significant and continued symptomatic, functional and vocational improvements over a 12-month period in a military population exposed to high intensity, weight-bearing exercise in uncontrolled and unforgiving environments.

Delayed discharges at a major arterial centre: a 4-month cross-sectional study at a single specialist vascular surgery ward.

OBJECTIVES: Delayed discharges are a significant problem for the National Health Service. The objectives of this study were to determine the prevalence and impact of delayed discharge at a single specialist vascular surgery ward. DESIGN: A cross-sectional observational study. SETTING: A single specialist vascular unit in the UK during a 4-month study period (01/09/2014-31/12/2014). PARTICIPANTS: All patients admitted to the ward during the study period were included. Patients spending ≥1 night on the ward once declared medically fit for discharge (MFFD) were prospectively identified and data prospectively collected. All other patients were identified retrospectively with data collected retrospectively from electronic records. OUTCOME MEASURES: Primary outcome was number of patients experiencing delayed discharge. Secondary outcome measures were length of stay, length of delay and cost of delay. RESULTS: There were 268 admissions with a total length of stay (LoS) of 2776 days. 57 admissions (21.3%) experienced delayed discharges with a total 535 excess bed days (19.3% total LoS) once MFFD. Unplanned admission (relative risk 7.3 (95% CI 2.7 to 20.0; p<0.001)) and index amputation (relative risk 9.2 (95% CI 3.8 to 22.0; p<0.001)) were associated with increased risk of delayed discharge. There were significant differences in the length of delay by the reason for the delay (p=0.01). Delay due to the provision of social services and inpatient rehabilitation were associated with longer length of delay (post hoc analysis). Age was not independently associated with either increased risk of delayed discharge or length of delay.The total estimated cost of delayed discharges during the study period was £146 055. CONCLUSIONS: A significant number of vascular patients experience delayed discharge. MFFD vascular patients occupy a high proportion of vascular beds at considerable financial cost. Unplanned admissions, amputees and those delayed due to social services contributed most to delays. Closer integration with community health and social care providers may reduce delays.

Does sensory relearning improve tactile function after carpal tunnel decompression? A pragmatic, assessor-blinded, randomized clinical trial.

Despite surgery for carpal tunnel syndrome being effective in 80%-90% of cases, chronic numbness and hand disability can occur. The aim of this study was to investigate whether sensory relearning improves tactile discrimination and hand function after decompression. In a multi-centre, pragmatic, randomized, controlled trial, 104 patients were randomized to a sensory relearning ( n = 52) or control ( n = 52) group. A total of 93 patients completed a 12-week follow-up. Primary outcome was the shape-texture identification test at 6 weeks. Secondary outcomes were touch threshold, touch localization, dexterity and self-reported hand function. No significant group differences were seen for the primary outcome (Shape-Texture Identification) at 6 weeks or 12 weeks. Similarly, no significant group differences were observed on secondary outcomes, with the exception of self-reported hand function. A secondary complier-averaged-causal-effects analysis showed no statistically significant treatment effect on the primary outcome. Sensory relearning for tactile sensory and functional deficits after carpal tunnel decompression is not effective. LEVEL OF EVIDENCE: II.

Thiosulfate oxidation by Thiomicrospira thermophila: metabolic flexibility in response to ambient geochemistry.

Previous studies of the stoichiometry of thiosulfate oxidation by colorless sulfur bacteria have failed to demonstrate mass balance of sulfur, indicating that unidentified oxidized products must be present. Here the reaction stoichiometry and kinetics under variable pH conditions during the growth of Thiomicrospira thermophila strain EPR85, isolated from diffuse hydrothermal fluids at the East Pacific Rise, is presented. At pH 8.0, thiosulfate was stoichiometrically converted to sulfate. At lower pH, the products of thiosulfate oxidation were extracellular elemental sulfur and sulfate. We were able to replicate previous experiments and identify the missing sulfur as tetrathionate, consistent with previous reports of the activity of thiosulfate dehydrogenase. Tetrathionate was formed under slightly acidic conditions. Genomic DNA from T. thermophila strain EPR85 contains genes homologous to those in the Sox pathway (soxAXYZBCDL), as well as rhodanese and thiosulfate dehydrogenase. No other sulfur oxidizing bacteria containing sox(CD)2 genes have been reported to produce extracellular elemental sulfur. If the apparent modified Sox pathway we observed in T. thermophila is present in marine Thiobacillus and Thiomicrospira species, production of extracellular elemental sulfur may be biogeochemically important in marine sulfur cycling.

Seeking the sun in deep, dark places: mesopelagic sightings of ocean sunfishes (Molidae).

Evidence is presented from publicly available remotely operated vehicle (ROV) footage that suggests deep-water ranging in ocean sunfishes (family Molidae) is more common than typically thought, including a new maximum depth recorded for the southern sunfish Mola ramsayi.

Outcomes of surgery for chronic exertional compartment syndrome in a military population.

AIM: To determine the outcome following fasciectomy for chronic exertional compartment syndrome (CECS) in the UK military, and the association between presurgical intramuscular pressure (IMP) and outcome. METHODS: All patients who underwent fasciectomy for anterior CECS were identified between 2007 and 2010. Presurgery and postsurgery military medical grading for leg function was extracted from the medical records system. The Wilcoxon signed-rank test compared grades before and after surgery. Spearman's rank correlation examined the relationship between IMP and outcome. RESULTS: Presurgery and postsurgery grading was available for 63% of patients. These patients had significantly better leg function after surgery (Z=-3.63, p<0.001). Of these, 49% improved by at least one grade, 36% showed no improvement in grading and 15% had a poorer outcome. There were no significant correlations between IMP and outcome. CONCLUSIONS: A large proportion of patients do not return to full fitness following fasciectomy in the military population. This is in line with a recent study in the US military, but conflicts with most civilian reports. The reasons for these differences are not clear. Furthermore, the lack of a relationship between IMP and outcome questions the role of pressure in this condition. These results suggest that the role of postoperative rehabilitation protocols and other conservative options should be explored.

Spatial variability in photosynthetic and heterotrophic activity drives localized δ13C org fluctuations and carbonate precipitation in hypersaline microbial mats.

Modern laminated photosynthetic microbial mats are ideal environments to study how microbial activity creates and modifies carbon and sulfur isotopic signatures prior to lithification. Laminated microbial mats from a hypersaline lagoon (Guerrero Negro, Baja California, Mexico) maintained in a flume in a greenhouse at NASA Ames Research Center were sampled for δ(13) C of organic material and carbonate to assess the impact of carbon fixation (e.g., photosynthesis) and decomposition (e.g., bacterial respiration) on δ(13) C signatures. In the photic zone, the δ(13) C org signature records a complex relationship between the activities of cyanobacteria under variable conditions of CO2 limitation with a significant contribution from green sulfur bacteria using the reductive TCA cycle for carbon fixation. Carbonate is present in some layers of the mat, associated with high concentrations of bacteriochlorophyll e (characteristic of green sulfur bacteria) and exhibits δ(13) C signatures similar to DIC in the overlying water column (-2.0‰), with small but variable decreases consistent with localized heterotrophic activity from sulfate-reducing bacteria (SRB). Model results indicate respiration rates in the upper 12 mm of the mat alter in situ pH and HCO3- concentrations to create both phototrophic CO2 limitation and carbonate supersaturation, leading to local precipitation of carbonate minerals. The measured activity of SRB with depth suggests they variably contribute to decomposition in the mat dependent on organic substrate concentrations. Millimeter-scale variability in the δ(13) C org signature beneath the photic zone in the mat is a result of shifting dominance between cyanobacteria and green sulfur bacteria with the aggregate signature overprinted by heterotrophic reworking by SRB and methanogens. These observations highlight the impact of sedimentary microbial processes on δ(13) C org signatures; these processes need to be considered when attempting to relate observed isotopic signatures in ancient sedimentary strata to conditions in the overlying water column at the time of deposition and associated inferences about carbon cycling.

Clinical Case of Immune Dysregulation, Polyendocrinopaty, Enteropathy, X-Linked (IPEX) Syndrome with Severe Immune Deficiency and Late Onset of Endocrinopathy and Enteropathy.

Objective. To describe the clinical characteristics of IPEX syndrome in a child with FOXP3 mutation. Clinical Case. A boy aged 2.3 years was born from first normal pregnancy with a weight of 3420 gr. Family History. Two brothers of the mother died before the age of 3 years with severe infections, diarrhea, erythroderma, and elevated immunoglobulins class E (IgEs). Since first month of life, our patient suffered from septicemia, pneumonias, pyelonephritis, and meningitis, accompanied with eczematous dermatitis and IgEs up to 4000 IU/L (normal <10). At the age of 1.6 years, he developed type 1 diabetes mellitus (T1DM). He was underweighted (-3.42 SDS) and had some phenotypic features like coarse face, muscle hypotonia, joint hyperextensibility, eczematous dermatitis, and subcutaneous cold abscesses. Autoimmune thyroiditis and celiac disease were excluded. After diabetes, intermittent watery diarrhea appeared with progression to severe intractable form. Finally, aggravating symptoms of nephritis, cachexia, and respiratory insufficiency were the cause for his death at the age of 2 years and 3 months. The DNA analysis at the University of Exeter Medical School established mutation at exon 10 of FOXP3 gene c.1010G >A, p. (Arg337Gln), which confirmed IPEX syndrome. The same mutation in heterozygotic state was found in the mother. A prenatal diagnosis of her second pregnancy ensured a daughter carrier of the mutation.

Energy expenditure during activity in the American lobster Homarus americanus: Correlations with body acceleration.

How animals manage time and expend energy has implications for survivorship. Being able to measure key metabolic costs of animals under natural conditions is therefore an important tool in behavioral ecology. One method for estimating activity-specific metabolic rate is via derived measures of acceleration, often 'overall dynamic body acceleration' (ODBA), recorded by an instrumented acceleration logger. ODBA has been shown to correlate well with rate of oxygen consumption (V˙o2) in a range of species during activity in the laboratory. This study devised a method for attaching acceleration loggers to decapod crustaceans and then correlated ODBA against concurrent respirometry readings to assess accelerometry as a proxy for activity-specific energy expenditure in a model species, the American lobster Homarus americanus. Where the instrumented animals exhibited a sufficient range of activity levels, positive linear relationships were found between V˙o2 and ODBA over 20min periods at a range of ambient temperatures (6, 13 and 20°C). Mixed effect linear models based on these data and morphometrics provided reasonably strong predictive power for estimating activity-specific V˙o2 from ODBA. These V˙o2-ODBA calibrations demonstrate the potential of accelerometry as an effective predictor of behavior-specific metabolic rate of crustaceans in the wild during periods of activity.

Improved genetic testing for monogenic diabetes using targeted next-generation sequencing.

AIMS/HYPOTHESIS: Current genetic tests for diagnosing monogenic diabetes rely on selection of the appropriate gene for analysis according to the patient's phenotype. Next-generation sequencing enables the simultaneous analysis of multiple genes in a single test. Our aim was to develop a targeted next-generation sequencing assay to detect mutations in all known MODY and neonatal diabetes genes. METHODS: We selected 29 genes in which mutations have been reported to cause neonatal diabetes, MODY, maternally inherited diabetes and deafness (MIDD) or familial partial lipodystrophy (FPLD). An exon-capture assay was designed to include coding regions and splice sites. A total of 114 patient samples were tested--32 with known mutations and 82 previously tested for MODY (n = 33) or neonatal diabetes (n = 49) but in whom a mutation had not been found. Sequence data were analysed for the presence of base substitutions, small insertions or deletions (indels) and exonic deletions or duplications. RESULTS: In the 32 positive controls we detected all previously identified variants (34 mutations and 36 polymorphisms), including 55 base substitutions, ten small insertions or deletions and five partial/whole gene deletions/duplications. Previously unidentified mutations were found in five patients with MODY (15%) and nine with neonatal diabetes (18%). Most of these patients (12/14) had mutations in genes that had not previously been tested. CONCLUSIONS/INTERPRETATION: Our novel targeted next-generation sequencing assay provides a highly sensitive method for simultaneous analysis of all monogenic diabetes genes. This single test can detect mutations previously identified by Sanger sequencing or multiplex ligation-dependent probe amplification dosage analysis. The increased number of genes tested led to a higher mutation detection rate.

SLC2A2 mutations can cause neonatal diabetes, suggesting GLUT2 may have a role in human insulin secretion.

AIMS: The gene SLC2A2 encodes GLUT2, which is found predominantly in pancreas, liver, kidney and intestine. In mice, GLUT2 is the major glucose transporter into pancreatic beta cells, and biallelic Slc2a2 inactivation causes lethal neonatal diabetes. The role of GLUT2 in human beta cells is controversial, and biallelic SLC2A2 mutations cause Fanconi-Bickel syndrome (FBS), with diabetes rarely reported. We investigated the potential role of GLUT2 in the neonatal period by testing whether SLC2A2 mutations can present with neonatal diabetes before the clinical features of FBS appear. METHODS: We studied SLC2A2 in patients with transient neonatal diabetes mellitus (TNDM; n = 25) or permanent neonatal diabetes mellitus (PNDM; n = 79) in whom we had excluded the common genetic causes of neonatal diabetes, using a combined approach of sequencing and homozygosity mapping. RESULTS: Of 104 patients, five (5%) were found to have homozygous SLC2A2 mutations, including four novel mutations (S203R, M376R, c.963+1G>A, F114LfsX16). Four out of five patients with SLC2A2 mutations presented with isolated diabetes and later developed features of FBS. Four out of five patients had TNDM (16% of our TNDM cohort of unknown aetiology). One patient with PNDM remains on insulin at 28 months. CONCLUSIONS: SLC2A2 mutations are an autosomal recessive cause of neonatal diabetes that should be considered in consanguineous families or those with TNDM, after excluding common causes, even in the absence of features of FBS. The finding that patients with homozygous SLC2A2 mutations can have neonatal diabetes supports a role for GLUT2 in the human beta cell.