Metallization of Shock-Compressed Liquid Ammonia.

Ammonia is predicted to be one of the major components in the depths of the ice giant planets Uranus and Neptune. Their dynamics, evolution, and interior structure are insufficiently understood and models rely imperatively on data for equation of state and transport properties. Despite its great significance, the experimentally accessed region of the ammonia phase diagram today is still very limited in pressure and temperature. Here we push the probed regime to unprecedented conditions, up to ∼350 GPa and ∼40 000 K. Along the Hugoniot, the temperature measured as a function of pressure shows a subtle change in slope at ∼7000 K and ∼90 GPa, in agreement with ab initio simulations we have performed. This feature coincides with the gradual transition from a molecular liquid to a plasma state. Additionally, we performed reflectivity measurements, providing the first experimental evidence of electronic conduction in high-pressure ammonia. Shock reflectance continuously rises with pressure above 50 GPa and reaches saturation values above 120 GPa. Corresponding electrical conductivity values are up to 1 order of magnitude higher than in water in the 100 GPa regime, with possible significant contributions of the predicted ammonia-rich layers to the generation of magnetic dynamos in ice giant interiors.

In situ marker-based assessment of leaf trait evolutionary potential in a marginal European beech population.

Evolutionary processes are expected to be crucial for the adaptation of natural populations to environmental changes. In particular, the capacity of rear edge populations to evolve in response to the species limiting conditions remains a major issue that requires to address their evolutionary potential. In situ quantitative genetic studies based on molecular markers offer the possibility to estimate evolutionary potentials manipulating neither the environment nor the individuals on which phenotypes are measured. The goal of this study was to estimate heritability and genetic correlations of a suite of leaf functional traits involved in climate adaptation for a natural population of the tree Fagus sylvatica, growing at the rear edge of the species range. Using two marker-based quantitative genetics approaches, we obtained consistent and significant estimates of heritability for leaf phenological (phenology of leaf flush), morphological (mass, area, ratio mass/area) and physiological (δ(13)C, nitrogen content) traits. Moreover, we found only one significant positive genetic correlation between leaf area and leaf mass, which likely reflected mechanical constraints. We conclude first that the studied population has considerable genetic diversity for important ecophysiological traits regarding drought adaptation and, second, that genetic correlations are not likely to impose strong genetic constraints to future population evolution. Our results bring important insights into the question of the capacity of rear edge populations to evolve.

Opioid receptor delta as a global modulator of skin differentiation and barrier function repair.

OBJECTIVES: The aims of this study were to confirm the properties of selective agonist peptide (Rubixyl) contained in the spinach towards opioid receptor delta. In fact, agonist properties of both spinach peptides (Rubiscolin-5 and Rubixyl) towards opioid receptor delta were demonstrated by Zang et al., but their effects on the other opioid receptors were not studied [1]. We also studied the expression of opioid receptor delta in epidermis under normal and stress condition (inflammatory) and its role in epidermis homeostasis under stress condition in vitro and in vivo. METHODS: Agonist properties studies were performed using functional agonist cellular model containing human opioid receptors. Opioid receptor delta expression and epidermis homeostasis were studied on human reconstructed epidermis under normal and stress conditions (inflammatory stress) using gene expression (RT-qPCR) and protein expression analysis (immunohistological analysis). Skin repair properties of opioid receptor delta agonist were based on the following parameters TEWL (trans epidermal water loss, hydration and wrinkle depth at periocular and perilabial area) on human volunteers having either intrinsic ageing (more than 40 years old and non-smoker group) and both intrinsic ageing and extrinsic ageing (more than 40 years old and smoker group). RESULTS: We have demonstrated that the Rubixyl peptide is a specific agonist of opioid receptor delta. We have demonstrated that opioid receptor delta expression is modulated under inflammatory condition. The agonist Rubixyl was able to block the depletion of opioid receptor delta seen under inflammatory condition in reconstructed human epidermis. Inflammatory conditions lead to the unbalanced gene and protein expressions of markers involved in epidermis integrity and barrier function properties. The treatment of human reconstructed epidermis with the agonist Rubixyl leads to the normalization of unbalanced gene and protein expressions. In vivo study has confirmed the efficiency of the agonist Rubixyl to repair damaged skin by decreasing TEWL, increasing hydration and decreasing wrinkle depth at the periocular and perilabial area. CONCLUSION: In this research, we have demonstrated in vitro (on inflamed reconstructed human epidermis, RHE) and in vivo (on human aged volunteers) that activation by natural agonist peptide of opioid receptor delta reduces the skin inflammation thus leading to improvement in epidermis differentiation and skin barrier properties.

Improvement of polyphenol properties upon glucosylation in a UV-induced skin cell ageing model.

OBJECTIVE: Polyphenols are strong antioxidant molecules allowing prevention of skin photo-ageing damages, but their use is limited due to low solubility and toxicity towards skin cells. We postulated that enzymatic glucosylation could improve their solubility, stability and, consequently, their efficacy. The aim of this work was to study changes induced by addition of a glucose moiety on two polyphenols displaying very different chemical structures [caffeic acid (CA), epigallocatechin-3-gallate (EGCG) and there glucosylated form, Glc-CA and Glc-EGCG] by assessing their cytotoxic properties and their antioxidant and anti-inflammatory activities. METHODS: Their antioxidant effect was assessed first by the classical DPPH radical-scavenging method. Then, a panel of human skin cells (keratinocytes, melanocytes, fibroblasts and endothelial cells) was used to evaluate their effect on cell toxicity and their antioxidant activities. With this aim, a photo-ageing model based on UV irradiation of skin cells was established. Molecule activity was assessed on reactive oxygen species (ROS) production, on superoxide dismutase (SOD) and catalase activities and, finally, on inflammatory factor production IL-6, IL-8 and IL-1ß. RESULTS: In an acellular model, antioxidant activity assessed by DPPH method was strongly reduced for Glc-CA compared to CA, whereas it remained the same for Glc-EGCG compared to EGCG. Glucosylated derivatives did not display more toxic effect on various skin cells. Moreover, toxicity was even strongly reduced for caffeic acid upon glucosylation. The efficacy of glucosyl-compounds against UV-induced ROS production was preserved, both with pre- and post-UV treatments. Particularly, a better antioxidant efficacy was shown by Glc-EGCG, vs. EGCG, on keratinocytes. In addition, an induction of SOD and catalase activity was clearly observed for Glc-CA. Both glucosyl-polyphenols display the same activity as their parent molecule in decreasing inflammatory factor production. CONCLUSION: Our results demonstrated that enzymatic glucosylation of CA and EGCG led to an improved or preserved antioxidant activity in a cellular model of UV-induced skin ageing, despite the decrease in instantaneous antioxidant properties observed for Glc-CA. Glc-EGCG is specifically more active on keratinocytes, suggesting a specific targeting. Such glucosylated polyphenols displaying improved physicochemical and biological properties should be better candidates than natural ones for use in food additives and cosmetics.

[What's new in hyperkalemia management?] / Nouveautés dans la prise en charge de l'hyperkaliémie.

Hyperkalemia is common in everyday clinical practice, and is a major risk factor for mortality. It mainly affects patients with chronic renal failure (CKD), diabetes or receiving treatment with inhibitors of the renin-angiotensin-aldosterone system (iRAAS). Therapeutic management aims not only to avoid the complications of hyperkalemia, but also to avoid discontinuation of cardio- and nephroprotective treatments such as iRAAS. The use of polystyrene sulfonate, widely prescribed, is often limited by patient acceptability. Recent data have cast doubt on its safety, particularly in terms of digestive tolerance. Two new potassium exchange molecules have appeared on the market: patiromer and zirconium sulfonate. Their value in clinical practice, and their acceptability in the event of prolonged prescription, remain to be demonstrated. The combination of a thiazide diuretic or an inhibitor of the sodium-glucose cotransporter type 2 (iSGLT2) with iRAAS therapy in CKD, may also improve control of kalemia. At present, there are no recommendations for the positioning of the various hypokalemic treatments. The choice of these treatments must be adapted to the patient's pathologies and consider the other expected effects of these molecules.

A warm layer in Venus' cryosphere and high-altitude measurements of HF, HCl, H2O and HDO.

Venus has thick clouds of H2SO4 aerosol particles extending from altitudes of 40 to 60 km. The 60-100 km region (the mesosphere) is a transition region between the 4 day retrograde superrotation at the top of the thick clouds and the solar-antisolar circulation in the thermosphere (above 100 km), which has upwelling over the subsolar point and transport to the nightside. The mesosphere has a light haze of variable optical thickness, with CO, SO2, HCl, HF, H2O and HDO as the most important minor gaseous constituents, but the vertical distribution of the haze and molecules is poorly known because previous descent probes began their measurements at or below 60 km. Here we report the detection of an extensive layer of warm air at altitudes 90-120 km on the night side that we interpret as the result of adiabatic heating during air subsidence. Such a strong temperature inversion was not expected, because the night side of Venus was otherwise so cold that it was named the 'cryosphere' above 100 km. We also measured the mesospheric distributions of HF, HCl, H2O and HDO. HCl is less abundant than reported 40 years ago. HDO/H2O is enhanced by a factor of approximately 2.5 with respect to the lower atmosphere, and there is a general depletion of H2O around 80-90 km for which we have no explanation.

Synergistic use of bioactive agents for the management of different skin conditions: an overview of biological activities.

Recently, many plant-derived bioactive agents have been included in dermo-cosmetics formulations. This leads to an extensive portfolio of innovative products with an expanded range of benefits, including anti-aging, antioxidant, hydrating and depigmenting. Although different technologies drawing on science and nature are used to create these high-performing molecules, there remains some debate about the mechanism of action of the natural bioactive ingredients within dermo-cosmetics. This review recapitulates the main biological mechanisms underlying the activity of natural active ingredients, with a specific focus on their synergistic use for the management of common, yet quite specific, skin conditions. A total of 28 plant-derived bioactives were selected from the Givaudan Active Beauty (Argenteuil, France) portfolio, a multinational company specializing in innovative natural actives research. An extensive literature review about their biological activity was conducted by a PubMed search using different keywords. No language or publication date restrictions were used. Givaudan Active Beauty data on file were also considered. The bioactive ingredients were described according to the pathogenetic mechanisms underlying 10 common skin conditions that dermo-cosmetics may address. Literature data have shown that plant-derived bioactives are involved in a wide range of biological mechanisms showing anti-inflammatory, antioxidant, and moisturizing properties, along with skin barrier protection and collagen synthesis activities. As a result, different combinations of bioactives within dermo-cosmetics can be defined to counteract simultaneously the different pathogenetic mechanisms underlying different skin conditions. Available literature supports the synergistic use of plant-derived bioactive agents within dermo-cosmetics as a viable and safe option for managing the most common skin conditions.

Review: Quality and authentication of organic animal products in Europe.

The 'organic' label guarantees a production process that avoids the use of synthetic fertilisers, pesticides and hormones and minimises the use of veterinary drugs; however, consumers are demanding guarantees regarding food quality. This article reviews the current state of knowledge on the quality of organic animal products, including the authentication of their organic origin. Quality has been considered as an integrative combination of six core attributes: commercial value, and nutritional, sensory, technological, convenience and safety attributes. The comparison of these attributes between organic and conventional animal products shows high heterogeneity due to variability in farming pratices in both organic and conventional systems. To overcome this, we pinpoint the farming practices underlying the differences observed. This enables light to be shed on the consequences of possible trajectories of organic farming, if specifications are relaxed or tightened up on commitments concerning farming practices that impact product quality. Two recent meta-analyses showed better nutritional attributes in organic milk and meat linked to their higher poly-unsaturated fatty acid (PUFA) content, particularly n-3 PUFAs. Regarding safety, we point to a lack of integrated studies quantifying the balance between positive and negative effects. Organic farming reduces the risk of drug residues and antibiotic resistance, but both outdoor rearing and a frequently longer rearing period increase the animals' exposition to environmental contaminants and the risk of their bioaccumulation in milk, eggs, meat and fish flesh. We highlight antagonisms between quality attributes for certain animal products (lamb, pork). In general, attributes are more variable for organic products, which can be explained by lower genetic selection (poultry), lower inputs and/or greater variability in farming conditions. However, the literature does not address the implications of this greater variability for the consumers' acceptability and the necessary adaptation of manufacturing processes. Further research is needed to document the impacts on human nutritional biomarkers and health. Methods used to authenticate organic origin are based on differences in animal diet composition between organic and conventional systems, but their reliability is hampered by the variability in farming practices.

Review: Quality of animal-source foods.

This article critically reviews the current state of knowledge on the quality of animal-source foods according to animal production and food processing conditions, including consumer expectations-behaviours and the effects of consumption of animal-source foods on human health. Quality has been defined through seven core attributes: safety, commercial, sensory, nutritional, technological, convenience, and image. Image covers ethical, cultural and environmental dimensions associated with the origin of the food and the way it is produced and processed. This framework enabled to highlight the priorities given to the different quality attributes. It also helped to identify potential antagonisms and synergies among quality attributes, between production and processing stages, and among stakeholders. Primacy is essentially given to commercial quality attributes, especially for standard commodity animal-source foods. This primacy has strongly influenced genetic selection and farming practices in all livestock commodity chains and enabled substantial quantitative gains, although at the expense of other quality traits. Focal issues are the destructuration of chicken muscle that compromises sensory, nutritional and image quality attributes, and the fate of males in the egg and dairy sectors, which have heavily specialised their animals. Quality can be gained but can also be lost throughout the farm-to-fork continuum. Our review highlights critical factors and periods throughout animal production and food processing routes, such as on-farm practices, notably animal feeding, preslaughter and slaughter phases, food processing techniques, and food formulation. It also reveals on-farm and processing factors that create antagonisms among quality attributes, such as the castration of male pigs, the substitution of marine-source feed by plant-based feed in fish, and the use of sodium nitrite in meat processing. These antagonisms require scientific data to identify trade-offs among quality attributes and/or solutions to help overcome these tensions. However, there are also food products that value synergies between quality attributes and between production and processing phases, particularly Geographical Indications, such as for cheese and dry-cured ham. Human epidemiological studies have found associations between consumption of animal-source foods and increased or decreased risk for chronic non-communicable diseases. These associations have informed public health recommendations. However, they have not yet considered animal production and food processing conditions. A concerted and collaborative effort is needed from scientists working in animal science, food process engineering, consumer science, human nutrition and epidemiology in order to address this research gap. Avenues for research and main options for policy action are discussed.

Variation of selfing rate and inbreeding depression among individuals and across generations within an admixed Cedrus population.

We investigated the variation and short-term evolution of the selfing rate and inbreeding depression (ID) across three generations within a cedar forest that was established from admixture ca 1860. The mean selfing rate was 9.5%, ranging from 0 to 48% among 20 seed trees (estimated from paternally inherited chloroplast DNA). We computed the probability of selfing for each seed and we investigated ID by comparing selfed and outcrossed seeds within progenies, thus avoiding maternal effects. In all progenies, the germination rate was high (88-100%) and seedling mortality was low (0-12%). The germination dynamics differed significantly between selfed and outcrossed seeds within progenies in the founder gene pool but not in the following generations. This transient effect of selfing could be attributed to epistatic interactions in the original admixture. Regarding the seedling growth traits, the ID was low but significant: 8 and 6% for height and diameter growth, respectively. These rates did not vary among generations, suggesting minor gene effects. At this early stage, outcrossed seedlings outcompeted their selfed relatives, but not necessarily other selfed seedlings from other progenies. Thus, purging these slightly deleterious genes may only occur through within-family selection. Processes that maintain a high level of genetic diversity for fitness-related traits among progenies also reduce the efficiency of purging this part of the genetic load.

Past climate changes explain the phylogeography of Vitellaria paradoxa over Africa.

The evolution of the savanna biome has been deeply marked by repeated contraction/expansion phases due to climate perturbations during the Quaternary period. In this study, we investigated the impact of the last glacial maximum (LGM) on the present genetic pattern of Vitellaria paradoxa (shea tree), a major African savanna tree. A range-wide sampling of the species enabled us to sample 374 individuals from 71 populations distributed throughout sub-Sahelian Africa. Trees were genotyped using 3 chloroplasts and 12 nuclear microsatellites, and were sequenced for 2 polymorphic chloroplast intergenic spacers. Analyses of genetic diversity and structure were based on frequency-based and Bayesian methods. Potential distributions of V. paradoxa at present, during the LGM and the last interglacial period, were examined using DIVA-GIS ecological niche modelling (ENM). Haplotypic and allelic richness varied significantly across the range according to chloroplast and nuclear microsatellites, which pointed to higher diversity in West Africa. A high but contrasted level of differentiation was revealed among populations with a clear phylogeographic signal, with both nuclear (F(ST) = 0.21; R(ST) = 0.28; R(ST) > R(ST) (permuted)) and chloroplast simple sequence repeats (SSRs) (G(ST) = 0.81; N(ST) = 0.90; N(ST) > N(ST) (permuted)). We identified a strong geographically related structure separating western and eastern populations, and a substructure in the eastern part of the area consistent with subspecies distinction. Using ENM, we deduced that perturbations during the LGM fragmented the potential eastern distribution of shea tree, but not its distribution in West Africa. Our main results suggest that climate variations are the major factor explaining the genetic pattern of V. paradoxa.

X-ray powder diffraction in reflection geometry on multi-beam kJ-type laser facilities.

An ultrafast x-ray powder diffraction setup for laser-driven dynamic compression has been developed at the LULI2000 laser facility. X-ray diffraction is performed in reflection geometry from a quasi-monochromatic laser-generated plasma x-ray source. In comparison to a transmission geometry setup, this configuration allows us to probe only a small portion of the compressed sample, as well as to shield the detectors against the x-rays generated by the laser-plasma interaction on the front side of the target. Thus, this new platform facilitates probing of spatially and temporarily uniform thermodynamic conditions and enables us to study samples of a large range of atomic numbers, thicknesses, and compression dynamics. As a proof-of-concept, we report direct structural measurements of the bcc-hcp transition both in shock and ramp-compressed polycrystalline iron with diffraction signals recorded between 2θ ∼ 30° and ∼150°. In parallel, the pressure and temperature history of probed samples is measured by rear-side visible diagnostics (velocimetry and pyrometry).

Long distance dispersal and the fate of a gene from the colonization front.

There is an increasing recognition that long distance dispersal (LDD) plays a key role in establishing spatial genetic structure during colonization. Recent works, focused on short distance dispersal, demonstrated that a neutral mutation arising at the colonization front can either 'surf' with the wave front and reach high frequencies or stay near its place of origin at low frequencies. Here, we examine how LDD, and more generally the shape of the dispersal kernel, modifies this phenomenon and how the width of the colonization corridor affects the fate of the mutation. We demonstrate that when LDD events are more frequent, the 'surfing phenomenon' is less frequent, probably because any alleles can get far ahead from the colonization front and preclude the invasion by others alleles, thus leading to an attenuation of the diversity loss. We also demonstrate that the width of the colonization corridor influences the fate of the mutation, wide spaces decreasing the probability of invasion. Overall, the genetic structure of diversity resulted not only from LDD but also particularly from the shape of the dispersal kernel.

Rapid changes in plasticity across generations within an expanding cedar forest.

We investigated the inter-individual variation of phenotypic plasticity and its evolution across three generations within an expanding forest. Plasticity was assessed in situ from dendrochronological data as the response of radial growth to summer rainfall. A linear mixed model was used to account for spatial effects (environment and stand structure), temporal factors (stand dynamics) and the variation with age. Beyond these effects, our results reveal a significant inter-individual variance of growth and plasticity within each generation. We also show that the mean values and variances of growth and plasticity changed significantly across generations, with different patterns for both traits. The possible environmental and genetic drivers of these changes are discussed. Contrasting with the trade-off between stress tolerance and plasticity generally observed among populations, we detected a positive covariance at the individual level, which does not support the cost of plasticity hypothesis in this case.

[Impact of PACS implementation in a university center on radiology practice profile]. / Changements des pratiques radiologiques induites par l'implantation d'un réseau images en milieu hospitalo-universitaire.

PURPOSE: To determine the impact of a joint PACS implementation at a university medical center and cancer center on the radiology practice profile. Materials and methods. In 5 radiology sections, patients, selected based on identifiable acute or chronic diseases, underwent US, CT or MRI. Data were collected on datasheets from each provider with regards to clinical history, availability of prior examinations, description of patient management during the different phases of the examination, duration of examinations, and satisfaction. Data obtained prior to PACS implementation and 6-12 months and 30-36 months after implementation were compared. RESULTS: A total of 1098 datasheets were collected. Hard copy readings rapidly decreased. Comparison with prior examinations improved (+20.6% to 25.6%) as well as frequency of post-processing (+29%). The time required for image management was much more reduced for technologists (-75%) than for physicians (-23%). PACS implementation only temporarily improved the availability of radiology reports and the distribution of work between senior and junior radiologists. User satisfaction, initially high, progressively decreased due to saturation of the archival capabilities. CONCLUSION: PACS implementation in a large university center improves the efficiency of image acquisition but does not solve some of the inefficiencies of hospital organization.

Laser-driven shock compression of "synthetic planetary mixtures" of water, ethanol, and ammonia.

Water, methane, and ammonia are commonly considered to be the key components of the interiors of Uranus and Neptune. Modelling the planets' internal structure, evolution, and dynamo heavily relies on the properties of the complex mixtures with uncertain exact composition in their deep interiors. Therefore, characterising icy mixtures with varying composition at planetary conditions of several hundred gigapascal and a few thousand Kelvin is crucial to improve our understanding of the ice giants. In this work, pure water, a water-ethanol mixture, and a water-ethanol-ammonia "synthetic planetary mixture" (SPM) have been compressed through laser-driven decaying shocks along their principal Hugoniot curves up to 270, 280, and 260 GPa, respectively. Measured temperatures spanned from 4000 to 25000 K, just above the coldest predicted adiabatic Uranus and Neptune profiles (3000-4000 K) but more similar to those predicted by more recent models including a thermal boundary layer (7000-14000 K). The experiments were performed at the GEKKO XII and LULI2000 laser facilities using standard optical diagnostics (Doppler velocimetry and optical pyrometry) to measure the thermodynamic state and the shock-front reflectivity at two different wavelengths. The results show that water and the mixtures undergo a similar compression path under single shock loading in agreement with Density Functional Theory Molecular Dynamics (DFT-MD) calculations using the Linear Mixing Approximation (LMA). On the contrary, their shock-front reflectivities behave differently by what concerns both the onset pressures and the saturation values, with possible impact on planetary dynamos.

A combined transcriptomic approach to analyse the dialogue between pseudorabies virus and porcine cells.

The pseudorabies virus (PrV), a porcine Alphaherpesvirus, is a good model for the study of virus-host cell dialog. As PrV has a strong tropism for mucous epithelial cells, we chose to follow in vitro the PrV time course-infection of porcine PK15 cells. The viral and cellular transcriptome modifications were simultaneously analysed using a combined SLA/PrV cDNA microarray, the porcine Qiagen-NRSP8 oligonucleotides microarray and real time quantitative PCR.Ahigh increase in viral gene expression was found from 4 h post-infection (PI), concomitantly to the first viral progeny and most viral genes were differentially expressed 12 h PI. No early global cellular shutoff was observed but many cellular genes were downregulated between 8 and 12 h PI, when UL41 transcripts encoding the virion shutoff protein, were first detected. Several genes involved in the MHC class I mediated antigenic pathway were downregulated including SLA-la, TAP1, TAP2, PSMB8 and PSMB9 genes. These results suggested that PrV prevents the viral antigen presentation by epithelial cells to cytotoxic T lymphocytes by decreasing transcription levels of SLA Ia mediated antigenic pathway genes. Other genes involved in the immune response, the apoptosis pathway, nucleic acid metabolism and cytoskeleton also appeared to be regulated during PrV infection. The combined approach will help to decipher host response evasion strategies developed by PrV and to study early cellular modifications.

[Evolution of the treatment of chronic post-traumatic aneurysms of the descending thoracic aorta: 30 years experience]. / Evolution du traitement des anévrismes post-traumatiques chroniques de l'aorte thoracique descendante: une expérience personnelle de 30 ans.

The authors present the early and late results of a series of 40 patients treated for chronic post-traumatic aneurysms of the descending thoracic aorta from 1975 to 2005. With the exception of a patient who died of an intra-pleural rupture before surgery, the patients were treated by aortotomy and prosthetic graft (N=17), aortotomy and direct suture (N=17) or endoprosthesis (N=5). The use of distal aortic perfusion in 22 patients enabled 17 direct sutures (77.3%) thanks to extensive mobilisation of the aortic arch. Endoprostheses have been used since 1997 in high surgical risk patients with severe comorbid conditions. There were no deaths, one transient paraparesia after simple aortic clamping, one reoperation for a haemothorax and four cases of dysphonia due to paralysis of the recurrent laryngeal nerve. Thirty-five patients (90%) were followed up for an average of 119.7 +/- 16.4 months. There were no clinical complications and the late morphological results were good in all cases with the exception of one type 1 endoprosthetic leak. The treatment of chronic post-traumatic aneurysms of the descending thoracic aorta gives excellent early and late results, justifying wide operative indications. The wish to avoid use of a prosthesis in young patients with a long life expectancy should give preference to conventional surgical techniques which, providing distal aortic perfusion is employed, allow direct suture of three quarters of cases. Endovascular treatment is reserved only for "poor surgical risks".

Molecular genetics of rust resistance in poplars (Melampsora larici-populina Kleb/Populus sp.) by bulked segregant analysis in a 2 x 2 factorial mating design.

With random amplified polymorphic DNA (RAPD) markers, we have tagged a genomic region in Populus sp. involved in qualitative resistance to Melampsora larici-populina. Our approach was based on three steps: use of RAPD markers that can be quickly and efficiently researched: application of "bulked segregant analysis" technique on individuals of one interspecific family P. trichocarpa x P. deltoides to search for RAPD markers linked to resistance; and validation of these markers in two other families linked with the first one in a 2 x 2 factorial mating design. Of five detected markers, only one marker M03/04_480 was polymorphic in the three segregating families, involving 89 individuals and four different parents. We have estimated the recombination value of 1 cM with 1 cM sampling error.

Iatrogenic complications in high-risk, elderly patients.

BACKGROUND: This study explores the quality improvement potential of reviewing care for long-stay, elderly medicine service patients hospitalized for congestive heart failure, acute myocardial infarction, or pneumonia at a large Midwestern teaching hospital. METHODS: Medical records were reviewed for 120 patients aged 65 years or older who were discharged between January 1987 and June 1989, with hospital stays of 15 days or longer. Patients' severity of illness on admission was rated using the Medicare Mortality Predictor System; process quality of care was rated using a structured implicit review form for judging several dimensions of clinical assessment and decision making. Serious complications were coded by etiology and type and judged as possibly or probably preventable. Logistic regression was used to identify risk factors for iatrogenic events; multiple regression was used to assess potential outcome bias in ratings of overall quality of care. RESULTS: Of 120 medical records reviewed, 70 (58.3%) suffered at least one iatrogenic complication. Forty-three patients (35.8%) suffered an iatrogenic complication rated as potentially preventable. Significant predictors of all iatrogenic complications were quality ratings of initial physician assessment, patients' inability to walk unassisted, and low Glasgow Coma Score. For potentially preventable complications, quality ratings for physician documentation of functional status were also significant. Ratings for overall quality of care were not significantly influenced by the mere presence of death or complications. CONCLUSIONS: Iatrogenic complications are likely to be an extremely common experience for elderly medicine service patients with long lengths of stay. A significant portion of these complications may be potentially preventable with closer attention to initial assessment and documentation of patients' functional status.