Urine neutrophil gelatinase-associated lipocalin predicts outcome and renal failure in open and endovascular thoracic abdominal aortic aneurysm surgery.

Urine neutrophil gelatinase-associated lipocalin (uNGAL) has been evaluated as a biomarker for AKI detection and adverse outcome in open and endovascular thoracoabdominal aortic aneurysm surgery. This observational, retrospective study included 52 patients. UNGAL was measured peri-operatively (48 h) and correlated with AKI requiring dialysis, tracheotomy and adverse outcome. Mean patients' age was 64.5 years. A total of 26.9% (n = 14) developed AKI, and 21.1% (n = 11) required dialysis, tracheotomy rate was 19.2% (n = 10) and in-hospital mortality rate was 7.6% (n = 4). uNGAL levels were related to AKI requiring dialysis at ICU (p = 0.0002), need for tracheotomy at baseline and admission on ICU (p = 0.0222, p = 0.0028, respectively), as well as adverse discharge modality (p = 0.0051, p = 0.0048, respectively). Diagnostic quality was good for uNGAL levels at admission to ICU regarding AKI requiring dialysis (sensitivity: 81.8% [48.2-97.7]; specificity: 87.8% [73.8-95.9]; area under the curve (AUC): 0.874 [0.752-0.949]). The diagnostic quality of uNGAL was favorable for the prediction of tracheotomy (sensitivity: 70.0% [34.8-93.3]; specificity: 83.3% [68.6-93.0]; AUC: 0.807 [0.674-0.903]) and adverse discharge (sensitivity: 77.8% [40.0-97.2]; specificity: 83.7% [69.3-93.2]; AUC: 0.817 [0.685-0.910]). uNGAL may be valuable as an post-operative predictor of AKI and adverse outcome after open and endovascular TAAA repair.

Endophlebectomy of the common femoral vein and arteriovenous fistula creation as adjuncts to venous stenting for post-thrombotic syndrome.

BACKGROUND: Good results have been reported for angioplasty and stenting of post-thrombotic lesions of the iliac and proximal femoral veins. If lesions at the origin of the superficial femoral and profunda veins are stented, the intraluminal synechiae can be pushed against the orifices of inflow vessels, potentially decreasing stent inflow. Surgical disobliteration of the common femoral vein (endophlebectomy) has been suggested to mitigate this problem. Because of a temporary increase in thrombogenicity, this procedure may be accompanied by arteriovenous fistula creation. METHODS: Data on consecutive patients treated by hybrid venous reconstruction, between December 2010 and May 2015, were analysed. Standard recording consisted of clinical scoring systems (including Villalta scale) and imaging. Patency was assessed with duplex ultrasonography. RESULTS: Seventy-six legs (70 patients) were included. Median follow-up was 379 (range 73-1508) days. Primary, assisted primary and secondary patency rates at 12 months were 51, 70 and 83 per cent respectively. Sixty per cent of loss of primary patency (24 of 40 legs) was related to common femoral vein stenosis, and the rest to rethrombosis. Other complications included wound infection (29 per cent) and lymphatic leak (39 per cent). The Villalta score had decreased by a median of 7 points at 1-year follow-up. CONCLUSION: The combination of venous stenting, endophlebectomy and arteriovenous fistula creation for patients with extensive post-thrombotic vein damage and severe post-thrombotic syndrome is feasible.

Interventional treatment of postthrombotic syndrome.

BACKGROUND: Postthrombotic syndrome (PTS) is the development of symptoms and signs of chronic venous insufficiency following deep vein thrombosis (DVT) and has a significant negative effect on the quality of life. The current understanding is that the clinical manifestation of PTS is related more to venous obstruction than it is to venous reflux. The use of interventional techniques for the treatment of venous obstruction and/or venous occlusion has rapidly increased in recent years. OBJECTIVE: This article summarizes the current concept of endovenous and hybrid interventions and presents the optimized treatment of choice in patients with chronic symptomatic venous obstruction. METHODS: We performed a systematic literature search in the Medline database to identify relevant studies on the treatment of patients with PTS. RESULTS: A meta-analysis of the relevant studies showed that this minimally invasive procedure is an effective treatment option with low morbidity and no mortality. Use of the newly developed dedicated venous stents showed promising results with good mid-term patency rates and a significant decrease in related symptoms. CONCLUSION: Interventional therapy for the treatment of symptomatic chronic venous obstruction has become the method of choice in recent years. More studies are needed to evaluate the long-term success rate of dedicated venous stents.

Effect of a new incision management system (PREVENA®) on wound healing after endophlebectomy of the common femoral vein: a case series.

BACKGROUND: New endovascular techniques facilitate treatment of complex deep vein obstructions in cases of post-thrombotic syndrome. In a relevant number of these patients, endophlebectomy including the implantation of an arteriovenous fistula between the common femoral artery and the femoral vein is indispensable in order to establish a good inflow. These procedures display a high risk of wound complications. Despite conservative efforts to prevent these postoperative complications, wound healing problems occur in more than 20 % of cases. The present case report is the first description of wound dressing using a PREVENA® incision management system in cases of endophlebectomy. CASE PRESENTATION: A single center's experience with the incision management system PREVENA®, which was used after endophlebectomy and venous stenting in complex hybrid procedures in three white men aged 46 years, 53 years, and 61 years is the subject of this case report. Although the surgical procedures were performed under therapeutical anticoagulation and took a couple of hours, no wound complications occurred. CONCLUSIONS: These encouraging results underline a potential benefit of the incision management system PREVENA® in cases of complex venous recanalization including endophlebectomy of the femoral vein as well as the implantation of an arteriovenous fistula.

[The Compression Syndrome of Lumbar Arteries - Case Report of a Rare Disease Pattern]. / Das Kompressionssyndrom der Lumbalarterien - Kasuistik eines seltenen Krankheitsbilds.

STUDY DESIGN: We present a monocentric analysis of the lumbar artery compression syndrome (LACS) in the form of a case report. OBJECTIVES: Literature information was collected about the symptoms, diagnosis and treatment of this rare disorder in the context of the existing data. METHODS: The current medical literature includes only one report about three cases of LACS, collected over 20 years in France and Germany. We compared these cases with the experience of the European Vascular Center Aachen-Maastricht. RESULTS: The symptoms of this rare disorder are dominated by reversible, motion-dependent paralysis of the legs. Compression of the right lumbar arteries by muscular fibres or connective tissue is a fundamental cause. CONCLUSION: Surgical treatment, which means decompression of the lumbar arteries via a thoracolaparotomy, is an appropriate therapy with few complications and good long-term results.

[Popliteal artery aneurysma as an important differential diagnosis]. / Das Poplitealarterienaneurysma als wichtige Differenzialdiagnose.

A common reason for painful lesions of the popliteal fossa are baker's cysts. An important differential diagnosis is the popliteal artery aneurysm, which is rare, but is associated with severe complications. The preferred method of diagnosis is the colour-coded duplex ultrasound. By showing the case of a 58-year-old man, who experienced life-threatening complications caused by an insufficient diagnosis before the operation of a Baker's cyst, we want to underline the importance of preoperative duplex ultrasound diagnosis in this context.

Late rupture after EVAR: a new trend?

AIM: Endovascular aortic repair (EVAR) is an adequate therapy for abdominal aortic aneurysms (AAA). Late aortic ruptures caused by endoleaks after EVAR still remain a critical issue. The aim of this study was to assess the causes of ruptured aortic aneurysms after EVAR in a single center study. METHODS: All patients, who were treated in our University hospital with a ruptured juxtra- or infrarenal AAA between January 2011 and October 2013, were included in this retrospective analysis. RESULTS: Thirty patients with ruptured infra- or juxtrarenal aneurysms were treated in this time frame. Six out of these 30 patients had previous EVAR repair. The median maximal aneurysm diameter of these post-EVAR patients was 82 (75-95) mm. The median time between primary EVAR and rupture was 42.5 (14-99) months. Three patients with type Ia endoleaks were treated by stent removal and conventional aortic reconstruction. In two patients with type II endoleak the bleeding was controlled by occluding the back bleeding lumbar arteries. One type III endoleak was sealed by an additional stent-graft implantation into the right iliac artery. CONCLUSION: We observed a considerable number of patients with a ruptured AAA after EVAR. Surprisingly, we observed two ruptured aneurysms due to type II endoleaks.

Association between circadian genes, bipolar disorders and chronotypes.

Abnormalities in circadian rhythms play an important role in the pathogenesis of bipolar disorders (BD). Previous genetic studies have reported discrepant results regarding associations between circadian genes and susceptibility to BD. Furthermore, plausible behavioral consequences of at-risk variants remain unclear since there is a paucity of correlates with phenotypic biomarkers such as chronotypes. Here, we combined association studies with a genotype/phenotype correlation in order to determine which circadian genes variants may be associated with the circadian phenotypes observed in patients with BD. First, we compared the allele frequencies of 353 single nucleotide polymorphisms spanning 21 circadian genes in two independent samples of patients with BD and controls. The meta-analysis combining both samples showed a significant association between rs774045 in TIMELESS (OR = 1.49 95%CI[1.18-1.88]; p = 0.0008) and rs782931 in RORA (OR = 1.31 95%CI[1.12-1.54]; p = 0.0006) and BD. Then we used a "reverse phenotyping approach" to look for association between these two polymorphisms and circadian phenotypes in a subsample of patients and controls. We found that rs774045 was associated with eveningness (p = 0.04) and languid circadian type (p = 0.01), whereas rs782931 was associated with rigid circadian type (p = 0.01). Altogether, these findings suggest that these variants in the TIMELESS and RORA genes may confer susceptibility to BD and impact on circadian phenotypes in carriers who thus had lower ability to properly adapt to external cues.

Stress tolerance and growth physiology of yeast strains from the Brazilian fuel ethanol industry.

Improved biofuels production requires a better understanding of industrial microorganisms. Some wild Saccharomyces cerevisiae strains, isolated from the fuel ethanol industry in Brazil, present exceptional fermentation performance, persistence and prevalence in the harsh industrial environment. Nevertheless, their physiology has not yet been systematically investigated. Here we present a first systematic evaluation of the widely used industrial strains PE-2, CAT-1, BG-1 and JP1, in terms of their tolerance towards process-related stressors. We also analyzed their growth physiology under heat stress. These strains were evaluated in parallel to laboratory and baker's strains. Whereas the industrial strains performed in general better than the laboratory strains under ethanol or acetic acid stresses and on industrial media, high sugar stress was tolerated equally by all strains. Heat and low pH stresses clearly distinguished fuel ethanol strains from the others, indicating that these conditions might be the ones that mostly exert selective pressure on cells in the industrial environment. During shake-flask cultivations using a synthetic medium at 37 °C, industrial strains presented higher ethanol yields on glucose than the laboratory strains, indicating that they could have been selected for this trait-a response to energy-demanding fermentation conditions. These results might be useful to guide future improvements of large-scale fuel ethanol production via engineering of stress tolerance traits in other strains, and eventually also for promoting the use of these fuel ethanol strains in different industrial bioprocesses.

Molecular characteristics of Human Endogenous Retrovirus type-W in schizophrenia and bipolar disorder.

Epidemiological and genome-wide association studies of severe psychiatric disorders such as schizophrenia (SZ) and bipolar disorder (BD), suggest complex interactions between multiple genetic elements and environmental factors. The involvement of genetic elements such as Human Endogenous Retroviruses type 'W' family (HERV-W) has consistently been associated with SZ. HERV-W envelope gene (env) is activated by environmental factors and encodes a protein displaying inflammation and neurotoxicity. The present study addressed the molecular characteristics of HERV-W env in SZ and BD. Hundred and thirty-six patients, 91 with BD, 45 with SZ and 73 healthy controls (HC) were included. HERV-W env transcription was found to be elevated in BD (P<10-4) and in SZ (P=0.012) as compared with HC, but with higher values in BD than in SZ group (P<0.01). The corresponding DNA copy number was paradoxically lower in the genome of patients with BD (P=0.0016) or SZ (P<0.0003) than in HC. Differences in nucleotide sequence of HERV-W env were found between patients with SZ and BD as compared with HC, as well as between SZ and BD. The molecular characteristics of HERV-W env also differ from what was observed in Multiple Sclerosis (MS) and may represent distinct features of the genome of patients with BD and SZ. The seroprevalence for Toxoplasma gondii yielded low but significant association with HERV-W transcriptional level in a subgroup of BD and SZ, suggesting a potential role in particular patients. A global hypothesis of mechanisms inducing such major psychoses is discussed, placing HERV-W at the crossroads between environmental, genetic and immunological factors. Thus, particular infections would act as activators of HERV-W elements in earliest life, resulting in the production of an HERV-W envelope protein, which then stimulates pro-inflammatory and neurotoxic cascades. This hypothesis needs to be further explored as it may yield major changes in our understanding and treatment of severe psychotic disorders.

Functional characterization of the oxaloacetase encoding gene and elimination of oxalate formation in the ß-lactam producer Penicillium chrysogenum.

Penicillium chrysogenum is widely used as an industrial antibiotic producer, in particular in the synthesis of ß-lactam antibiotics such as penicillins and cephalosporins. In industrial processes, oxalic acid formation leads to reduced product yields. Moreover, precipitation of calcium oxalate complicates product recovery. We observed oxalate production in glucose-limited chemostat cultures of P. chrysogenum grown with or without addition of adipic acid, side-chain of the cephalosporin precursor adipoyl-6-aminopenicillinic acid (ad-6-APA). Oxalate accounted for up to 5% of the consumed carbon source. In filamentous fungi, oxaloacetate hydrolase (OAH; EC3.7.1.1) is generally responsible for oxalate production. The P. chrysogenum genome harbours four orthologs of the A. niger oahA gene. Chemostat-based transcriptome analyses revealed a significant correlation between extracellular oxalate titers and expression level of the genes Pc18g05100 and Pc22g24830. To assess their possible involvement in oxalate production, both genes were cloned in Saccharomyces cerevisiae, yeast that does not produce oxalate. Only the expression of Pc22g24830 led to production of oxalic acid in S. cerevisiae. Subsequent deletion of Pc22g28430 in P. chrysogenum led to complete elimination of oxalate production, whilst improving yields of the cephalosporin precursor ad-6-APA.

Intermediate high index layer for laser mode tuning in organic semiconductor lasers.

We modified the optical properties of organic semiconductor distributed feedback lasers by introducing a high refractive index layer consisting of tantalum pentoxide between the substrate and the active material layer. A thin film of tris-(8-hydroxyquinoline) aluminium doped with the laser dye 4-dicyanomethylene-2-methyl-6-(p-dimethylamino-styryl)-4H-pyran was used as the active layer. By varying the intermediate layer thickness we could change the effective refractive index of the guided laser mode and thus the laser wavelength. With this technique we were able to tune the laser emission range between 613 nm and 667 nm. For high index layer thicknesses higher than 40 nm the laser operated on the TE(1)-mode rather than the fundamental TE(0)-mode.

Simple and robust method for estimation of the split between the oxidative pentose phosphate pathway and the Embden-Meyerhof-Parnas pathway in microorganisms.

The flux through the oxidative pentose phosphate (PP) pathway was estimated in Bacillus clausii, Saccharomyces cerevisiae, and Penicillium chrysogenum growing in chemostats with [1-(13)C]glucose as the limiting substrate. The flux calculations were based on a simple algebraic expression that is valid irrespective of isotope rearrangements arising from reversibilities of the reactions in the PP pathway and the upper part of the Embden-Meyerhof-Parnas pathway. The algebraically calculated fluxes were validated by comparing the results with estimates obtained using a numerical method that includes the entire central carbon metabolism. Setting the glucose uptake rate to 100, the algebraic expression yielded estimates of the PP pathway flux in B. clausii, S. cerevisiae, and P. chrysogenum of 20, 42, and 75, respectively. These results are in accordance with the results from the numerical method. The information on the labeling patterns of glucose and the proteinogenic amino acids were obtained using gas chromatography / mass spectrometry, which is a very sensitive technique, and therefore only a small amount of biomass is needed for the analysis. Furthermore, the method developed in this study is fast and readily accessible, as the calculations are based on a simple algebraic expression.

Network identification and flux quantification in the central metabolism of Saccharomyces cerevisiae under different conditions of glucose repression.

The network structure and the metabolic fluxes in central carbon metabolism were characterized in aerobically grown cells of Saccharomyces cerevisiae. The cells were grown under both high and low glucose concentrations, i.e., either in a chemostat at steady state with a specific growth rate of 0.1 h(-1) or in a batch culture with a specific growth rate of 0.37 h(-1). Experiments were carried out using [1-(13)C]glucose as the limiting substrate, and the resulting summed fractional labelings of intracellular metabolites were measured by gas chromatography coupled to mass spectrometry. The data were used as inputs to a flux estimation routine that involved appropriate mathematical modelling of the central carbon metabolism of S. cerevisiae. The results showed that the analysis is very robust, and it was possible to quantify the fluxes in the central carbon metabolism under both growth conditions. In the batch culture, 16.2 of every 100 molecules of glucose consumed by the cells entered the pentose-phosphate pathway, whereas the same relative flux was 44.2 per 100 molecules in the chemostat. The tricarboxylic acid cycle does not operate as a cycle in batch-growing cells, in contrast to the chemostat condition. Quantitative evidence was also found for threonine aldolase and malic enzyme activities, in accordance with published data. Disruption of the MIG1 gene did not cause changes in the metabolic network structure or in the flux pattern.

Very compact tunable solid-state laser utilizing a thin-film organic semiconductor.

Optically pumped organic semiconductor lasers are fabricated by evaporation of a thin film of tris(8-hydroxyquinoline) aluminum (Alq(3)) molecularly doped with a laser dye on top of a polyester substrate with an embossed grating structure. We achieve low-threshold, longitudinally monomode distributed-feedback laser operation. By varying the film thickness of the organic semiconductor film, we can tune the wavelength of the surface-emitting laser over 44 nm. The low laser threshold allows the use of a very compact all-solid-state pump laser ( approximately 10 cm long). This concept opens up a way to obtain inexpensive lasers that are tunable over the whole visible range.

Lipase production by Penicillium restrictum using solid waste of industrial babassu oil production as substrate.

Lipase, protease, and amylase production by Penicillium restrictum in solid-state fermentation was investigated. The basal medium was an industrial waste of babassu oil (Orbignya oleifera) production. It was enriched with peptone, olive oil, and Tween-80. The supplementation positively influenced both enzyme production and fungal growth. Media enriched with Tween-80 provided the highest protease activity (8.6 U/g), whereas those enriched with peptone and olive oil led to the highest lipase (27.8 U/g) and amylase (31.8 U/g) activities, respectively.

Mathematical modelling of metabolism.

Mathematical models of the cellular metabolism have a special interest within biotechnology. Many different kinds of commercially important products are derived from the cell factory, and metabolic engineering can be applied to improve existing production processes, as well as to make new processes available. Both stoichiometric and kinetic models have been used to investigate the metabolism, which has resulted in defining the optimal fermentation conditions, as well as in directing the genetic changes to be introduced in order to obtain a good producer strain or cell line. With the increasing availability of genomic information and powerful analytical techniques, mathematical models also serve as a tool for understanding the cellular metabolism and physiology.

Recombinant gene expression in Escherichia coli cultivation using lactose as inducer.

The use of lactose as inducer of foreign gene expression under control of the lac UV5 promoter was investigated in recombinant Escherichia coli. Chicken muscle troponin C (TnC) gene was transcripted by T7 RNA polymerase and expressed in bioreactor cultivations after a feed-forward controlled fed-batch growth phase. Cell concentrations of 22 g l-1 dry cell weight (DCW)--before induction started--were used to achieve a TnC content of 19.5% of total cell protein through an induction strategy that combined the addition of a specific lactose amount of 4.7 g g-1 DCW divided into three pulses and the addition of yeast extract (1 g l-1) together with the second and the third lactose pulses. The results presented suggest that the residual lactose concentration plays an important role on the production of the heterologous protein.

Influence of incoherent superposition of light on ellipsometric coefficients.

Reflections from the back surface of a transparent substrate influence the evaluation of optical constants of thin films from ellipsometric measurements. If the thickness of the substrate is large compared with the coherence length of the light, the relative phase between the p and s mode, which commonly is measured by ellipsometry, cannot be defined properly. We show how the reflections from the back surface of the substrate are taken into account in ellipsometric measurements by calculating the intensities of reflections for arbitrary angles of polarization. Applications of the new method, such as transmittance ellipsometry, ellipsometry at the back surface of the substrate, and the determination of the optical constants at the substrate-layer interface, are compared with measurements.

Epidemiology and morbidity of regional anesthesia in children: a one-year prospective survey of the French-Language Society of Pediatric Anesthesiologists.

We report the results of a prospective study on the practice of pediatric regional anesthesia by the French-Language Society of Pediatric Anesthesiologists (ADARPEF) during the period from May 1, 1993 to April 30, 1994. This study was designed to provide data concerning the epidemiology of regional anesthesia and its complications in a totally anonymous way. Data from 85,412 procedures, 61,003 pure general anesthetics and 24,409 anesthetics including a regional block, were prospectively collected. Central blocks (15,013), most of which were caudals, accounted for more than 60% of all regional anesthetics. Peripheral nerve blocks and local anesthesia techniques represented only 38% of regional blocks and Bier block was used only 69 times. Central and peripheral nerve blocks were performed in all pediatric age groups with some intergroup differences. Most blocks were performed under light general anesthesia (89%), confirming the fact that regional anesthetics are used as techniques of analgesia rather than anesthesia. Complications were rate (25 incidents involving 24 patients) and minor, and did not result in any sequelae or medicolegal action. Peripheral nerve blocks and local anesthesia techniques were generally safe. The overall complication rate of regional anesthesia was 0.9 per 1000, but because all complications occurred with central blocks, the complication rate of central blocks is in fact 1.5 per 1000 with significant variations in different age groups. This prospective study, based on a large and representative series of pediatric anesthetics, establishes the safety of regional anesthesia in children of all ages. It provides new insights on the practice of regional blocks and reveals that complications are rare and minor as they occur most often in the operating room and are readily managed by experienced anesthesiologists with resuscitative equipment at hand. The extremely low incidence of complications (zero in this study) after peripheral nerve blocks should encourage pediatric anesthesiologists to use them more often when they are appropriate, in the place of a central block.