Trends in hydroidomedusan research from 1911 to 1997

The papers on hydroidomedusae published from 1911 to 1997 total 10,934. They have been assigned to the following categories: faunistics and systematics; sub-organismal biology; ecology; evolution; life cycles; paleontology. The general trend, comprising all papers, can be divided into four time intervals: the first (1911-1939) with an average of sixty papers/year and with a slight decrease due to First World War; the second one (1940-1947), with an average of 38 papers/year, marked by a dramatic decrease coinciding with Second World War; the period 1948-1991 shows a steady increase until the mid-Seventies, when a small decrease occurred, followed by an increasing trend reaching its apex in the late Eighties-early Ninenties with a record of 296 papers in 1991 and with an average of 175 papers/year; the period 1992 1997, with an average of 178 papers/year, is marked by a sharp decrease, reaching the values of the mid Sixties. The most important category in terms of number of papers is sub-organismal biology, followed by faunistics and systematics. Systematic studies dictated the trend in the first decades of the century, whereas sub-organismal ones are prevalent from the Sixties onwards. Faunistic and systematic-taxonomic papers have a steady trend of production, with just a slight decrease over these last years. The formerly leading countries in systematics (UK, USA, France) are now almost inactive in this discipline, whereas countries with little or no tradition in this field (such as Spain) are taking the leadership

Tracing carbon assimilation in endosymbiotic deep-sea hydrothermal vent mytilid fatty acids by ¹³C-fingerprinting

Bathymodiolus azoricus mussels thrive at Mid-Atlantic Ridge hydrothermal vents, where part oftheir energy requirements are met via an endosymbiotic association with chemolithotrophic and methanotrophic bacteria. In an effort to describe phenotypic characteristics of the two bacterial endosymbionts and to assesstheir ability to assimilate CO2, CH4 and multi-carbon compounds, we performed experiments in aquaria using 13C-labeled NaHCO3 (in the presence of H2S), CH4 or amino-acids and traced the incorporation of 13C into total and phospholipid fatty acids (tFA and PLFA, respectively). 14:0; 15:0; 16:0; 16:1(n - 7)c+t; 18:1(n - 13)c+t and (n - 7)c+t; 20:1(n - 7); 20:2(n - 9,15); 18:3(n - 7) and (n - 5,10,13) PLFA were labeled in the presence of H13CO3- (+H2S) and 13CH4, while the 12:0 compound became labeled only in the presence ofH13CO3- (+H2S). In contrast, the 17:0; 18:0; 16:1(n - 9); 16:1(n - 8) and (n - 6); 18:1(n - 8); and 18:2(n - 7) PLFA were only labeled in the presence of 13CH4. Some of these symbiont-specific fatty acids also appeared to be labeled in mussel gill tFA when incubated with 13C-enriched amino acids, and so were mussel-specific fatty acids such as 22:2(n - 7,15). Our results provide experimental evidence for the potential of specific fatty acid markers to distinguish between the two endosymbiotic bacteria, shedding new light on C1 and multi-carbon compound metabolic pathways in B. azoricus and its symbionts

Cross-validation of two prognostic trauma scores in severely injured patients

Introduction Trauma scoring systems are important tools for outcome prediction and severity adjustment that informs trauma quality assessment and research. Discrimination and precision of such systems is tested in validation studies. The German TraumaRegister DGU® (TR-DGU) and the Trauma Audit and Research Network (TARN) from the UK agreed on a cross-validation study to validate their prediction scores (RISC II and PS14, respectively). Methods Severe trauma patients with an Injury Severity Score (ISS) ≥ 9 documented in 2015 and 2016 were selected in both registries (primary admissions only). The predictive scores from each registry were applied to the selected data sets. Observed and predicted mortality were compared to assess precision; area under the receiver operating characteristic curve was used for discrimination. Hosmer–Lemeshow statistic was calculated for calibration. A subgroup analysis including patients treated in intensive care unit (ICU) was also carried out. Results From TR-DGU, 40,638 patients were included (mortality 11.7%). The RISC II predicted mortality was 11.2%, while PS14 predicted 16.9% mortality. From TARN, 64,622 patients were included (mortality 9.7%). PS14 predicted 10.6% mortality, while RISC II predicted 17.7%. Despite the identical cutoff of ISS ≥ 9, patient groups from both registries showed considerable difference in need for intensive care (88% versus 18%). Subgroup analysis of patients treated on ICU showed nearly identical values for observed and predicted mortality using RISC II. Discussion Each score performed well within its respective registry, but when applied to the other registry a decrease in performance was observed. Part of this loss of performance could be explained by different development data sets: the RISC II is mainly based on patients treated in an ICU, while the PS14 includes cases mainly cared for outside ICU with more moderate injury severity. This is according to the respective inclusion criteria of the two registries. Conclusion External validations of prediction models between registries are needed, but may show that prediction models are not fully transferable to other health-care settings

Ondansetron does not reduce the shivering threshold in healthy volunteers

Background. Ondansetron, a serotonin-3 receptor antagonist, reduces postoperative shivering. Drugs that reduce shivering usually impair central thermoregulatory control, and may thus be useful for preventing shivering during induction of therapeutic hypothermia. We determined, therefore, whether ondansetron reduces the major autonomic thermoregulatory response thresholds (triggering core temperatures) in humans. Methods. Control (placebo) and ondansetron infusions at the target plasma concentration of 250 ng ml−1 were studied in healthy volunteers on two different days. Each day, skin and core temperatures were increased to provoke sweating; then reduced to elicit peripheral vasoconstriction and shivering. We determined the core-temperature sweating, vasoconstriction and shivering thresholds after compensating for changes in mean-skin temperature. Data were analysed using t-tests and presented as means (sds); P<0.05 was taken as significant. Results. Ondensetron plasma concentrations were 278 (57), 234 (55) and 243 (58) ng ml−1 at the sweating, vasoconstriction and shivering thresholds, respectively; these corresponded to ≈50 mg of ondansetron which is approximately 10 times the dose used for postoperative nausea and vomiting. Ondansetron did not change the sweating (control 37.4 (0.4)°C, ondansetron 37.6 (0.3)°C, P=0.16), vasoconstriction (37.0 (0.5)°C vs 37.1 (0.3)°C; P=0.70), or shivering threshold (36.3 (0.5)°C vs 36.3 (0.6)°C; P=0.76). No sedation was observed on either study day. Conclusions. Ondansetron appears to have little potential for facilitating induction of therapeutic hypothermi

Predictors of 25(OH)D half-life and plasma 25(OH)D concentration in The Gambia and the UK

Summary: Predictors of 25(OH)D3 half-life were factors associated with vitamin D metabolism, but were different between people in The Gambia and the UK. Country was the strongest predictor of plasma 25(OH)D concentration, probably as a marker of UVB exposure. 25(OH)D3 half-life may be applied as a tool to investigate vitamin D expenditure.  Introduction: The aim of this study was to investigate predictors of 25(OH)D3 half-life and plasma 25(OH)D concentration.  Methods: Plasma half-life of an oral tracer dose of deuterated-25(OH)D3 was measured in healthy men aged 24–39 years, resident in The Gambia, West Africa (n = 18) and in the UK during the winter (n = 18), countries that differ in calcium intake and vitamin D status. Plasma and urinary markers of vitamin D, calcium, phosphate and bone metabolism, nutrient intakes and anthropometry were measured.  Results: Normally distributed data are presented as mean (SD) and non-normal data as geometric mean (95 % CI). Gambian compared to UK men had higher plasma concentrations of 25(OH)D (69 (13) vs. 29 (11) nmol/L; P < 0.0001); 1,25(OH)2D (181 (165, 197) vs. 120 (109, 132) pmol/L; P < 0.01); and parathyroid hormone (PTH) (50 (42, 60) vs. 33 (27, 39); P < 0.0001). There was no difference in 25(OH)D3 half-life (14.7 (3.5) days vs. 15.6 (2.5) days) between countries (P = 0.2). In multivariate analyses, 25(OH)D, 1,25(OH)2D, vitamin D binding protein and albumin-adjusted calcium (Caalb) explained 79 % of variance in 25(OH)D3 half-life in Gambians, but no significant predictors were found in UK participants. For the countries combined, Caalb, PTH and plasma phosphate explained 39 % of half-life variability. 1,25(OH)2D, weight, PTH and country explained 81 % of variability in 25(OH)D concentration; however, country alone explained 74 %.  Conclusion: Factors known to affect 25(OH)D metabolism predict 25(OH)D3 half-life, but these differed between countries. Country predicted 25(OH)D, probably as a proxy measure for UVB exposure and vitamin D supply. This study supports the use of 25(OH)D half-life to investigate vitamin D metabolism