Validation of the emergency surgery score (ESS) in a UK patient population and comparison with NELA scoring: a retrospective multicentre cohort study.

INTRODUCTION: Accurate risk scoring in emergency general surgery (EGS) is vital for consent and resource allocation. The emergency surgery score (ESS) has been validated as a reliable preoperative predictor of postoperative outcomes in EGS but has been studied only in the US population. Our primary aim was to perform an external validation study of the ESS in a UK population. Our secondary aim was to compare the accuracy of ESS and National Emergency Laparotomy Audit (NELA) scores. METHODS: We conducted an observational cohort study of adult patients undergoing emergency laparotomy over three years in two UK centres. ESS was calculated retrospectively. NELA scores and all other variables were obtained from the prospectively collected Emergency Laparotomy and Laparoscopic Scottish Audit (ELLSA) database. The primary and secondary outcomes were 30-day mortality and postoperative intensive care unit (ICU) admission, respectively. RESULTS: A total of 609 patients were included. Median age was 65 years, 52.7% were female, the overall mortality was 9.9% and 23.8% were admitted to ICU. Both ESS and NELA were equally accurate in predicting 30-day mortality (c-statistic=0.78 (95% confidence interval (CI), 0.71-0.85) for ESS and c-statistic=0.83 (95% CI, 0.77-0.88) for NELA, p=0.196) and predicting postoperative ICU admission (c-statistic=0.76 (95% CI, 0.71-0.81) for ESS and 0.80 (95% CI, 0.76-0.85) for NELA, p=0.092). CONCLUSIONS: In the UK population, ESS and NELA both predict 30-day mortality and ICU admission with no statistically significant difference but with higher c-statistics for NELA score. Both scores have certain advantages, with ESS being validated for a wider range of outcomes.

Flower colour polymorphism in the Mediterranean Basin: occurrence, maintenance and implications for speciation.

Flower colour polymorphism (FCP) is the occurrence of at least two discrete flower colour variants in the same population. Despite a vast body of research concerning the maintenance and evolutionary consequences of FCP, only recently has the spatial variation in morph frequencies among populations been explored. Here we summarise the biochemical and genetic basis of FCP, the factors that have been proposed to explain their maintenance, and the importance of FCP and its geographic variation in the speciation process. We also review the incidence of FCP in the environmentally heterogeneous Mediterranean Basin. Nearly 88% of Mediterranean FCP species showed anthocyanin-based polymorphisms. Concerning the evolutionary mechanisms that contribute to maintain FCP, selection by pollinators is suggested in some species, but in others, selection by non-pollinator agents, genetic drift or gene flow are also found; in some cases different processes interact in the maintenance of FCP. We emphasise the role of both autonomous selfing and clonal reproduction in FCP maintenance. Mediterranean polymorphic species show mainly monomorphic populations with only a few polymorphic ones, which generate clinal or mosaic patterns of variation in FCP. No cases of species with only polymorphic populations were found. We posit that different evolutionary processes maintaining polymorphism the Mediterranean Basin will result in a continuum of geographic patterns in morph compositions and relative frequencies of FCP species.

Contemporary evolution of plant reproductive strategies under global change is revealed by stored seeds.

Global change is expected to impose new selection pressures on natural populations. Phenotypic responses, such as earlier phenology in response to climate warming, have been repeatedly observed in the field. The recent pollinator decline is also expected to change selection on reproductive traits in flowering plants. However, it remains unclear whether short-term adaptation of plant reproductive strategies occurs in response to global change. In this study, we report the evolution of some important reproductive traits of the annual self-incompatible weed Centaurea cyanus. In a common garden experiment, we germinated stored seeds, sampled 18 years apart from the same location, in a region where warmer springs and indices of pollinator decline have been reported. Compared to the ancestral population (1992), our results showed that plants of the descendant population (2010) flowered earlier and also produced larger capitula with longer receptivity and a larger floral display. QST -FST comparisons indicated that natural selection has likely contributed to the evolution of some of the traits investigated. Lower FST within temporal samples than among spatial samples further suggests a limited role of gene flow from neighbouring populations. We therefore propose that trait shifts could partly be due to adaptation to global change.

Positive effect of the yellow morph on female reproductive success in the flower colour polymorphic Iris lutescens (Iridaceae), a deceptive species.

The deceptive Iris lutescens (Iridaceae) shows a heritable and striking flower colour polymorphism, with both yellow- and purple-flowered individuals growing sympatrically. Deceptive species with flower colour polymorphism are mainly described in the family Orchidaceae and rarely found in other families. To explain the maintenance of flower colour polymorphism in I. lutescens, we investigated female reproductive success in natural populations of southern France, at both population and local scales (within populations). Female reproductive success was positively correlated with yellow morph frequency, at both the population scale and the local scale. Therefore, we failed to observe negative frequency-dependent selection (NFDS), a mechanism commonly invoked to explain flower colour polymorphism in deceptive plant species. Flower size and local flower density could also affect female reproductive success in natural populations. Pollinator behaviour could explain the positive effect of the yellow morph, and our results suggest that flower colour polymorphism might not persist in I. lutescens, but alternative explanations not linked to pollinator behaviour are discussed. In particular, NFDS, although an appealingly simple explanation previously demonstrated in orchids, may not always contribute to maintaining flower colour polymorphism, even in deceptive species.

Past and current gene flow in the selfing, wind-dispersed species Mycelis muralis in western Europe.

The distribution of genetic diversity in Mycelis muralis, or wall lettuce, was investigated at a European scale using 12 microsatellite markers to infer historical and contemporary forces from genetic patterns. Mycelis muralis has the potential for long-distance seed dispersal by wind, is mainly self-pollinated, and has patchily distributed populations, some of which may show metapopulation dynamics. A total of 359 individuals were sampled from 17 populations located in three regions, designated southern Europe (Spain and France), the Netherlands, and Sweden. At this within-region scale, contemporary evolutionary forces (selfing and metapopulation dynamics) are responsible for high differentiation between populations (0.34 < F(ST) < 0.60) but, contrary to expectation, levels of within-population diversity, estimated by Nei's unbiased expected heterozygosity (H(E)) (0.24 < H(E) < 0.68) or analyses of molecular variance (50% of the variation found within-populations), were not low. We suggest that the latter results, which are unusual in selfing species, arise from efficient seed dispersal that counteracts population turnover and thus maintains genetic diversity within populations. At the European scale, northern regions showed lower allelic richness (A = 2.38) than populations from southern Europe (A = 3.34). In light of postglacial colonization hypotheses, these results suggest that rare alleles may have been lost during recolonization northwards. Our results further suggest that mutation has contributed to genetic differentiation between southern and northern Europe, and that Sweden may have been colonized by dispersers originating from at least two different refugia.

Expression of leukocyte adhesion molecules by endothelial cells seeded on various polymer surfaces.

Although endothelial cell seeding in small-diameter vascular prostheses significantly improves graft survival, the detachment of adherent endothelial cells after the restoration of circulation remains one of the major obstacles. Because in vivo experiments indicate that leukocyte infiltration is involved in endothelial cell loss, we hypothesize that seeded endothelial cells become activated and express leukocyte adhesion molecules and cytokines because of an interaction with the underlying polymer surface. The aim of this study was to investigate the expression of the leukocyte adhesion molecules ICAM-1, VCAM-1, PECAM-1, and E-selectin by cultured human umbilical vein endothelial cells (HUVECs) and human adipose microvascular endothelial cells (HAMVECs). The cells were seeded on tissue culture poly(styrene) and the vascular graft materials Dacron and Teflon. The results of this study indicate that the expression of leukocyte adhesion molecules by cultured endothelial cells is mainly affected by the endothelial cell origin, that is, umbilical vein or adipose tissue. Expressions of both ICAM-1 and E-selectin by HUVECs and HAMVECs are characterized by the presence of two cell populations with distinct levels of expression. With respect to endothelial cell seeding in vascular prostheses, the increased expression of E-selectin by microvascular endothelial cells deserves further attention.

Capitulum characters in a seed heteromorphic plant, Crepis sancta (Asteraceae): variance partitioning and inference for the evolution of dispersal rate.

In Crepis sancta (Asteraceae), achenes produced in the periphery of the flower head have reduced dispersal ability and are larger than achenes produced in the centre of the head, which disperse farther. The proportion of central achenes produced by a single individual represents the potential dispersal rate of its progeny. Seed variation in dispersal ability may be important where there is spatio-temporal variability of habitats, but its evolutionary significance mainly depends on the heritability of the relative proportions of each achene morph. However, the number of peripheral achenes in a capitulum, and that of involucral bracts are suggested to depend on the number of parastichies, a canalized character. From a diallel cross design, phenotypic variance for several capitulum traits was partitioned among six variance components, including the additive variance. The phenotypic values of some head traits reflected the expected frequency due to ontogeny, in particular the number of involucral bracts. Yet, this character also had a significant heritability, suggesting that variation around the mode of the distribution was not only due to developmental noise. The additive variance for number of peripheral and central achenes was not significantly different from zero. In contrast, their respective proportion had a narrow sense heritability greater than 0.20. The present results suggest that the percentage of central achenes per individual, and thus the potential dispersal rate in Crepis sancta, is under quantitative genetic control, and could undergo microevolutionary changes in natural populations.

[Changes in pharmacists practices (1996 - 2000) related to harm reduction policy (condoms, injecting equipment, methylmorphine) and maintenance therapy delivery (buprenorphine, methadone)]. / Evolution de l'implication du pharmacien d'officine dans la prévention des dommages liés à l'usage de drogues et la dispensation des traitements de substitution.

AIMS: To measure pharmacists involvement in harm reduction programs and in delivery of maintenance therapies in order to estimate their contribution to the new public health policy. METHOD: A longitudinal study was conducted among 327 pharmacies located in the southern suburban area of Paris (28 communities) using a standardized questionnaire. RESULTS: The response rate was 95% in 1996 and 92% in 2000. The number of condoms offered to intravenous drug users (IDU) decreased dramatically from 99% to 24% while delivered units decreased from 857 to 566 per day for needles and from 1200 to 760 per month per pharmacy for methylmorphine tablets (14.93 mg/tablet). Pharmacists delivered injecting equipment to some of their patients under opiate treatment: methylmorphine 19%, buprenorphine 35%, methadone 14%. Their contribution to the local healthcare network on addiction decreased from 38% to 20%. Nevertheless, the pharmacists attitude towards the IDU and public health policy was found to be improving with problems being mentioned for 62% of the cases in 1996 and for 16% in 2000. CONCLUSION: Pharmacists are rapidly and intensively changing their practices and are discovering a new comprehensive relationship with IDU. Better pharmacist involvement is associated with a shift in local healthcare network concentration, reinforcing the general practitioner-pharmacist partnership.

Different growth behaviour of human umbilical vein endothelial cells and an endothelial cell line seeded on various polymer surfaces.

Major obstacles for successful application of endothelial cell seeding in synthetic vascular grafts include the source of autologous endothelial cells, the efficiency of cell seeding and detachment of adherent endothelial cells from the graft surface after restoration of circulation. Human umbilical vein endothelial cells (HUVECs) are frequently used to investigate the in vitro adhesion and proliferation of endothelial cells on polymer surfaces. In order to minimize the biological variation of HUVECs isolated from different umbilical veins, it would be advantageous to use an endothelial cell line in in vitro proliferation experiments. Aim of the present study was to compare the proliferation of primary HUVECs and the endothelial cell line EC-RF24 on several polymer surfaces coated with various concentrations of the adhesive protein fibronectin. EC-RF24 cells grow to a higher density than primary HUVECs. Moreover, the EC-RF24 cell line is able to proliferate on surfaces with sub-optimal adhesive properties. Therefore, it is concluded that the EC-RF24 cell line is less suitable for evaluation of the in vitro proliferation of endothelial cells on polymer surfaces.

Fractionation of RNA polymerase II transcription factors from HeLa cell nuclear extracts by affinity chromatography on "DNA-like" phosphorylated polystyrene.

It was previously shown that phosphorylated cross-linked polystyrene derivatives specifically interacted with anti-DNA antibodies and anti-phospholipid antibodies present in the sera of systemic lupus erythematosus patients. These resins are potential candidates as stationary phases in affinity chromatography. We wondered whether these biospecific resins might allow the fractionation of DNA binding proteins such as RNA polymerase II transcription factors from HeLa cell nuclear extracts. Indeed, these proteins play a major role in gene regulation in mammalian cells and their purification still requires numerous steps. To study the biospecificity of DNA-like phosphorylated polystyrene derivatives, ethanolamine sulfamide crosslinked polystyrene derivatives were phosphorylated at various rates and HeLa cell nuclear extracts were adsorbed on these resins. Adsorbed proteins were eluted with increasing concentrations of aqueous potassium chloride. Collected fractions were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the biological activities of the eluted transcription factors were tested by in vitro transcription assay. Results showed that the elution of transcription factors depended on the substitution rate in phosphoester groups of the resins. It appears that specific interactions were developed between the polymers and the transcription factors. Moreover, the eluted transcription factors kept their biological activity. These results lead us to propose the purification of RNA polymerase II transcription factors using the phosphorylated polystyrene resins as stationary phases.

Randomly phosphorylated polystyrene derivatives interact with RNA polymerase II transcription factors: part I.

Insoluble functional synthetic random copolymers are able to develop at their surfaces specific interactions with biologic components. Crosslinked phosphorylated polystyrene derivatives were previously shown to mimic DNA antigen because they interacted with anti-DNA antibodies found in the sera of systemic lupus erythematosus patients. These biospecific surfaces were postulated to be able to bind other DNA-binding proteins such as RNA polymerase II transcription factors. Indeed, these proteins play a major role in gene regulation in mammalian cells. This hypothesis was checked by adsorption and elution of HeLa cell nuclear extracts on a 72% phosphorylated resin. The composition of the eluted fractions were analyzed by electrophoresis, and the biologic activity of the transcription factors was tested using an in vitro transcription assay. The results showed that USF, TATA-binding protein (TBP), and TFIIB were specifically adsorbed on the polymer and that all eluted factors kept their biologic activity. Therefore, randomly phosphorylated polystyrene derivatives may be useful for the fractionation of RNA polymerase II transcription factors.

Clinical and microbiological evaluation of a postdilutional hemofiltration system with in-line production of substitution fluid.

Safety and efficacy of a recently developed hemofiltration (HF) system with in-line production of substitution fluid (GHS-10; Gambro, Lund, Sweden) based on a sterilizing filtration of acetate buffered dialysate has been evaluated in 4 patients over a 6-month period. Two patients were prematurely excluded from the study: 1 because of acetate intolerance and the other because of kidney transplantation. Two patients completed the study (240 HF sessions). Treatment adequacy was maintained in the 2 medium term treated patients according to the usual clinical and biochemical criteria and a mean exchange volume of 100-105 liters/week (30-35 liters/session three times weekly). Urea kinetic modeling analysis performed over all HF cycles gave the following results: dialysis index (urea clearance.time-on HF/urea volume space) (KT/V) approximately 1-1.1, urea time averaged concentration (UREA TAC) approximately 15-20 mmol/l, and protein catabolic rate (PCR) approximately 1.1-1.2 g/kg/day. Rare clinical adverse symptoms observed during the course of sessions were attributed to acetate intolerance. Microbiological safety was confirmed in vivo by the absence of pyrogenic reactions after 240 HF sessions (approximately 7 m3 substitution fluid infused intravenously) and in vitro by the constant absence of bacteria and/or endotoxin content limulus amaebocyte lysate (LAL) sensibility threshold 10 pg/l within the infusate produced during the sham HF sessions. The fluid mass balance obtained with the GHS-10 monitor was excellent. The electrolyte composition as judged by Na variation remained in a range of 2-3%. GHS-10 used in this study for postdilutional HF confirms that a large quantity of intravenous quality fluid may be safely produced by ultrafiltration from dialysate. It also introduced a new dimension in biocompatibility of dialysis by demonstrating that sterile dialysate may be routinely produced and used for routine dialysis.

Cytolytically active murine T-lymphocyte/polyoma virus-transformed fibroblast hybrids.

It would be of great interest to obtain permanent T-cell lines retaining specific activity without either allogeneic or xenogeneic stimulation. Functionally active hybrids between cytolytic T cells and thymoma were previously reported, but they had to be selected in a TCGF-containing medium. This study contains new results and reports the preparation of a hybrid cell from a cytolytic T cell and a polyoma virus-infected fibroblast, in which the T-cell characteristics dominate over the polyoma-transformed characteristics. A differentiated T-cell function (i.e., cytolysis) persists and the differentiated line does not require TCGF. The loss of cytolytic activity during in vitro evolution may be due to a selection favouring transformed cells, as suggested by concomitant enhancement of the transformed phenotype and chromosome loss.