10 research outputs found
The rhizosphere microbiota of the zinc and cadmium hyperaccumulators Arabidopsis halleri and Noccaea caerulescens is highly convergent in Prayon (Belgium)
The Prayon site is known as a zinc-polluted area where two zinc and cadmium hyperaccumulator plant species currently coexist, although Arabidopsis halleri was introduced more recently than Noccaea caerulescens . While soil microorganisms may influence metal uptake, the microbial community present in the rhizosphere of hyperaccumulators remains poorly known. Plants of both species were sampled with their bulk and rhizosphere soil from different plots of the Prayon site. Soil components (ionome, pH, water composition, temperature) were analyzed, as well as shoot ionome and expression levels of metal transporter genes ( HMA3 , HMA4 , ZIP4 / ZNT1 , ZIP6 , MTP1 ). The taxonomic diversity of the microorganisms in soil samples was then determined by 16S rRNA metabarcoding and compared at the Operational Taxonomy Unit (OTU) level and across different taxonomic levels. Our elemental analyses confirmed that the site is still highly contaminated with zinc and cadmium and that both plant species indeed hyperaccumulate these elements in situ . Although the pollution is overall high, it is heterogenous at the site scale and correlates with the expression of some metal transporter genes. Metabarcoding analyses revealed a decreasing gradient of microbial diversity, with more OTUs discovered in the rhizosphere than in the soil bulk, especially at the bottom of the cores. However, the variability gradient increases with the distance from roots. Using an ad hoc pseudo-taxonomy to bypass the biases caused by a high proportion of unclassified and unknown OTUs, we identified Chloroflexi, Armatimonadetes, Pirellulaceae, Gemmatimonadetes and Chitinophagaceae as the drivers of the differences in the gradient along the cores. In contrast, no significant difference was identified between the rhizosphere composition of A. halleri and N. caerulescens . This suggests that, despite their distinct colonization history in Prayon, the two plant species have now recruited highly convergent microbial communities in the rhizosphere
Single cell RNA sequencing to uncover intestinal cell-type specific cis-eQTL driving inherited predisposition to IBD
IBD is characterized by a chronic idiopathic inflammation of the gastrointestinal (GI) tract and consist of two main forms: ulcerative colitis and Crohn’s disease. The importance of genetic susceptibility has been well established through Genome Wide Association Studies (GWAS), which have identified over 200 risk loci for IBD. However, the « true causative » genes in these loci have been identified for only few on the basis of independently associated coding variants. Fine-mapping studies suggested that most risk variants cause “cis”-eQTL in disease relevant cell types, but recent post-GWAS studies could not find matching cis-eQTLs for the majority of risk loci (137/200). This indicates that the relevant cell types were either not present amongst the analyzed cell populations or under-represented.
In this study, we performed cis-eQTL analysis with single cell RNA-seq of human gut biopsies to uncover the truly relevant cell types with higher resolution and unbiased approach. Biopsies were collected from three GI locations (ileum, transverse colon, rectum) from the same individuals. Cell suspensions were prepared, tagged by location and cell fraction using TotalseqB hashtag antibodies for multiplexing and processed to the 10X Genomics Chromium. Data were analyzed using Cellranger and Seurat to identify the cell clusters and marker genes. In total, 50 individuals’ biopsies data were integrated. Simultaneously, genotype was analyzed with Infinium OmniExpress-24v1 chip from 1 ml blood and imputed. Both scRNA-seq data and imputed genotypes were input to qtltools v1.3.1 for cis-eQTL anlaysis. Analysis are actually ongoing and will certainly generate new set of cell-based eQTL and determine whether some of these drive inherited predisposition to IBD by comparing the corresponding expression association patterns with disease association patterns using methods developed in our laboratory
Early liver transplantation for severe alcohol-related hepatitis not responding to medical treatment: a prospective controlled study
peer reviewedBackground: Early liver transplantation for severe alcohol-related hepatitis is an emerging treatment option. We aimed to assess the risk of alcohol relapse 2 years after early liver transplantation for alcohol-related hepatitis compared with liver transplantation for alcohol-related cirrhosis after at least 6 months of abstinence. Methods: We conducted a multicentre, non-randomised, non-inferiority, controlled study in 19 French and Belgian hospitals. All participants were aged 18 years or older. There were three groups of patients recruited prospectively: patients with severe alcohol-related hepatitis who did not respond to medical treatment and were eligible for early liver transplantation according to a new selection scoring system based on social and addiction items that can be quantified in points (early transplantation group); patients with alcohol-related cirrhosis listed for liver transplantation after at least 6 months of abstinence (standard transplantation group); patients with severe alcohol-related hepatitis not responding to medical treatment not eligible for early liver transplantation according to the selection score (not eligible for early transplantation group), this group did not enter any further liver transplantation processes. We also defined a historical control group of patients with severe alcohol-related hepatitis unresponsive to medical therapy and non-transplanted. The primary outcome was the non-inferiority of 2-year rate of alcohol relapse after transplantation in the early transplantation group compared with the standard transplantation group using the alcohol timeline follow back (TLFB) method and a prespecified non-inferiority margin of 10%. Secondary outcomes were the pattern of alcohol relapse, 2-year survival rate post-transplant in the early transplantation group compared with the standard transplantation group, and 2-year overall survival in the early transplantation group compared with patients in the not eligible for early transplantation group and historical controls. This trial is registered with ClinicalTrials.gov, NCT01756794. Findings: Between Dec 5, 2012, and June 30, 2016, we included 149 patients with severe alcohol-related hepatitis: 102 in the early transplantation group and 47 in the not eligible for early transplantation group. 129 patients were included in the standard transplantation group. 68 patients in the early transplantation group and 93 patients in the standard transplantation group received a liver transplant. 23 (34%) patients relapsed in the early transplantation group, and 23 (25%) patients relapsed in the standard transplantation group; therefore, the non-inferiority of early transplantation versus standard transplantation was not demonstrated (absolute difference 9·1% [95% CI –∞ to 21·1]; p=0·45). The 2-year rate of high alcohol intake was greater in the early transplantation group than the standard transplantation group (absolute difference 16·7% [95% CI 5·8–27·6]) The time spent drinking alcohol was not different between the two groups (standardised difference 0·24 [95% CI −0·07 to 0·55]), but the time spent drinking a large quantity of alcohol was higher in the early transplantation group than the standard transplantation group (standardised difference 0·50 [95% CI 0·17–0·82]). 2-year post-transplant survival was similar between the early transplantation group and the standard transplantation group (hazard ratio [HR] 0·87 [95% CI 0·33–2·26]); 2-year overall survival was higher in the early transplantation group than the not eligible for early transplantation group and historical controls (HR 0·27 [95% CI 0·16–0·47] and 0·21 [0·13–0·32]). Interpretation: We cannot conclude non-inferiority in terms of rate of alcohol relapse post-transplant between early liver transplantation and standard transplantation. High alcohol intake is more frequent after early liver transplantation. This prospective controlled study confirms the important survival benefit related to early liver transplantation for severe alcohol-related hepatitis; and this study provides objective data on survival and alcohol relapse to tailor the management of patients with severe alcohol-related hepatitis. Funding: The present study has been granted by the French Ministry of Health—Programme Hospitalier de Recherche Clinique 2010
De behandeling van het Tweede Wereldoorlogtrauma in de naoorlogse Nederlandstalige literatuur : Analyse en vergelijking van G.L. Durlachers Strepen aan de hemel (1985) en Jessica Durlachers Het geweten (1997)
Hoewel het meer dan 70 jaar geleden is dat er een einde aan de Tweede Wereldoorlog kwam, speelt die nog steeds een belangrijke rol in het collectieve geheugen. In deze scriptie komt de behandeling van het Tweede Wereldoorlogtrauma in de naoorlogse Nederlandstalige literatuur aan bod. Daarvoor wordt een vergelijkend onderzoek gedaan naar twee bepaalde literaire werken uit de naoorlogse Nederlandstalige literatuur, namelijk Gerhard Leopold Durlachers Strepen aan de hemel (1985) en Jessica Durlachers Het geweten (1997). De klemtoon van deze scriptie ligt op de manier waarop het Tweede Wereldoorlogtrauma wordt behandeld in de naoorlogse Nederlandstalige literatuur en meer precies in de voorafgaande geciteerde boeken. Daarvoor concentreert deze scriptie zich rond twee onderzoeksvragen. Ten eerste vraag ik me af of er in beide boeken sprake is van een Tweede Wereldoorlogtrauma. Als dat wel het geval is, wat zijn de elementen die getuigen van zo’n trauma? Ten tweede zou ik graag willen weten of het genre van de boeken een bepaalde invloed heeft op de manier waarop het Tweede Wereldoorlogtrauma wordt behandeld. Krijgt het literaire werk een andere dimensie, een toegevoegde waarde omdat het behoort tot de autobiografie of tot de autobiografische roman? Om deze onderzoeksvragen te kunnen beantwoorden wordt mijn scriptie in drie grote delen onderverdeeld. In het eerste staat de wetenschappelijke literatuur over de Tweede Wereldoorlog, het begrip trauma en het autobiografisch schrijven in het middelpunt. In het tweede gaat het om het leven en de werken van de auteurs om beter te begrijpen waarom ze respectievelijk het Tweede Wereldoorlogtrauma in hun boeken behandelen. Ten slotte komt het praktische deel waarin de theorie op de situatie van de personages wordt toegepast.Master [120] en langues et lettres modernes, orientation germaniques, Université catholique de Louvain, 201
Short communication: Evaluation of the microbiota of kefir samples using metagenetic analysis targeting the 16S and 26S ribosomal DNA fragments
Milk kefir is produced by fermenting milk in the presence of kefir grains. This beverage has several benefits for human health. The aim of this experiment was to analyze 5 kefir grains (and their products) using a targeted metagenetic approach. Of the 5 kefir grains analyzed, 1 was purchased in a supermarket, 2 were provided by the Ministry of Agriculture (Namur, Belgium), and 2 were provided by individuals. The metagenetic approach targeted the V1-V3 fragment of the 16S ribosomal (r)DNA for the grains and the resulting beverages at 2 levels of grain incorporation (5 and 10%) to identify the bacterial species population. In contrast, the 26S rDNA pyrosequencing was performed only on kefir grains with the aim of assessing the yeast populations. In parallel, pH measurements were performed on the kefir obtained from the kefir grains using 2 incorporation rates. Regarding the bacterial population, 16S pyrosequencing revealed the presence of 20 main bacterial species, with a dominance of the following: Lactobacillus kefiranofaciens, Lactococcus lactis ssp. cremoris, Gluconobacter frateurii, Lactobacillus kefiri, Acetobacter orientalis, and Acetobacter lovaniensis. An important difference was noticed between the kefir samples: kefir grain purchased from a supermarket (sample E) harbored a much higher proportion of several operational taxonomic units of Lactococcus lactis and Leuconostoc mesenteroides. This sample of grain was macroscopically different from the others in terms of size, apparent cohesion of the grains, structure, and texture, probably associated with a lower level of Lactobacillus kefiranofaciens. The kefir (at an incorporation rate of 5%) produced from this sample of grain was characterized by a lower pH value (4.5) than the others. The other 4 samples of kefir (5%) had pH values above 5. Comparing the kefir grain and the kefir, an increase in the population of Gluconobacter in grain sample B was observed. This was also the case for Acetobacter orientalis in sample D. In relation to 26S pyrosequencing, our study revealed the presence of 3 main yeast species: Naumovozymaspp., Kluyveromyces marxianus, and Kazachastania khefir. For Naumovozyma, further studies are needed to assess the isolation of new species. In conclusion, this study has proved that it is possible to establish the patterns of bacterial and yeast composition of kefir and kefir grain. This was only achieved with the use of high-throughput sequencing techniques
Study of the microbial diversity of microbial ring trials by metagenomic analysis : Quantification of alive bacteria by exclusion of dead bacteria
Consequences of Pneumoperitoneum on Liver Ischemia During Laparoscopic Portal Triad Clamping in a Swine Model.
BACKGROUND: Portal triad clamping (PTC) may be required during laparoscopic liver resection to limit blood loss. The aim of this study was to test in a swine model the hypothesis that during laparoscopic PTC, increased intraperitoneal pressure may alter hepatic vein reverse circulation, inducing a more severe hepatic ischemia compared with PTC performed in laparotomy. METHODS: Fifteen pigs were randomized into three groups: laparoscopy (1 h of pneumoperitoneum at 15 mmHg and 3 h of surveillance), open PTC (1 h PTC through laparotomy and 3 h of reperfusion), and laparoscopic PTC (1 h PTC with 15 mmHg pneumoperitoneum and 3 h of reperfusion). PTC was performed under mesenteric decompression using a veno-venous splenofemoral bypass. Hepatic partial oxygen tension and microcirculatory flow were continuously measured using a Clarke-type electrode and a laser Doppler flow probe, respectively. Liver consequences of PTC was assessed by right atrium serum determination of transaminases, creatinine, bilirubin, INR, and several ischemia/reperfusion parameters, drawn before PTC (T0), before unclamping (T60), and 1 (T120) and 3 h after reperfusion (T240). Histology was performed on T240 liver biopsies. RESULTS: Compared with open PTC, laparoscopic PTC produced a more rapid and more severe decrease in hepatic oxygen tension, indicating a more severe tissular hypoxia, and a more severe decrease in hepatic microcirculatory flow, indicating a decrease in hepatic backflow. At T240, the laparoscopic PTC livers suffered from a higher degree of hepatocellular damage, shown by higher transaminases and increased necrotic index at pathology. CONCLUSIONS: These results indicate that in this pig model, laparoscopic PTC induces a more severe liver ischemia, related to decreased hepatic oxygen content and decreased hepatic backflow. If confirmed by clinical studies, these results may indicate that caution is necessary when performing prolonged PTC during laparoscopic hepatic resection, particularly in cirrhotic or steatotic livers
Laparoscopic versus open liver resection for intrahepatic cholangiocarcinoma. Report of an international multicenter cohort study with propensity score matching
Background: Intrahepatic cholangiocarcinoma is a rare disease with a poor prognosis. In patients where surgical resection is possible, outcome is influenced by perioperative morbidity and lymph node status. Laparoscopic liver resection is associated with improved clinical and oncological outcomes in primary and metastatic liver cancer compared with open liver resection, but evidence on intrahepatic cholangiocarcinoma is still insufficient.The primary aim of this study was to compare overall survival for a large series of patients treated for intrahepatic cholangiocarcinoma by open or laparoscopic approach. Secondary objectives were to compare disease-free survival, predictors of death, and recurrence.Methods: Patients treated with laparoscopic or open liver resection for intrahepatic cholangiocarcinoma from 2000 to 2018 from 3 large international databases were analyzed retrospectively. Each patient in the laparoscopic resection group (case) was matched with 1 open resection control (1:1 ratio), through a propensity score calculated on clinically relevant preoperative covariates. Overall and disease-free survival were compared between the matched groups. Predictors of mortality and recurrence were analyzed with Cox regression, and the Textbook Outcomes were described.Results: During the study period, 855 patients met the inclusion criteria (open liver resection = 709, 82.9%; laparoscopic liver resection = 146, 17.1%). Two groups of 89 patients each were analyzed after propensity score matching, with no significant difference regarding pre-and postoperative variables. Overall survival at 1, 3, and 5 years was 92%, 75%, and 63% in the laparoscopic liver resection group versus 92%, 58%, and 49% in the open liver resection group (P = .0043). Adjusted Cox regression revealed severe postoperative complications (hazard ratio: 10.5, 95% confidence interval [1.01-109] P = .049) and steatosis (hazard ratio: 13.8, 95% confidence interval [1.23-154] P = .033) as predictors of death, and transfusion (hazard ratio: 19.2, 95% confidence interval [4.04-91.4] P < .001) and severe postoperative complications (hazard ratio: 4.07, 95% confidence interval [1.15-14.4] P = .030) as predictors of recurrence.Conclusion: The survival advantage of laparoscopic liver resection over open liver resection for intrahepatic cholangiocarcinoma is equivocal, given historical bias and missing data. (C) 2021 Elsevier Inc. All rights reserved