Colon capsule versus computed tomography colonography for colorectal cancer screening in patients with positive fecal occult blood test who refuse colonoscopy: a randomized trial.

OBJECTIVE: Some patients (10 % - 32 %) with a positive guaiac fecal occult blood test (gFOBT) do not undergo the recommended colonoscopy. The aim of this study was to compare video capsule endoscopy (VCE) and computed tomography colonography (CTC) in terms of participation rate and detection outcomes when offered to patients with a positive gFOBT who did not undergo the recommended colonoscopy. METHODS: An invitation letter offering CTC or VCE was sent to selected patients after randomization. Acceptance of the proposed (or alternative) procedure and procedure results were recorded. Sample size was evaluated according to the hypothesis of a 13 % increase of participation with VCE. RESULTS: A total of 756 patients were targeted. Following the invitation letter, 5.0 % (19/378) of patients underwent the proposed VCE and 7.4 % (28/378) underwent CTC, (P = 0.18). Following the letter, 9.8 % (37/378) of patients in the VCE group underwent a diagnostic procedure (19 VCE, 1 CTC, 17 colonoscopy) vs. 10.8 % in the CTC group (41/378: 28 CTC, 13 colonoscopy; P = 0.55). There were more potentially neoplastic lesions diagnosed in the VCE group than in the CTC group (12/20 [60.0 %] vs. 8/28 [28.6 %]; P = 0.04). Thus, 15/20 noninvasive procedures in the VCE group (19 VCE, 1 CTC; 75.0 %) vs. 10/28 in the CTC group (35.7 %; P = 0.01) resulted in a recommendation of further colonoscopy, but only 10/25 patients actually underwent this proposed colonoscopy. CONCLUSION: Patients with a positive gFOBT result who do not undergo the recommended colonoscopy are difficult to recruit to the screening program and simply proposing an additional, less-invasive procedure, such as VCE or CTC, is not an effective strategy.ClinicalTrials.govNCT02558881TRIAL REGISTRATION: Randomized, controlled trial NCT02558881 at clinicaltrials.gov.

Homogeneous time-resolved G protein-coupled receptor-ligand binding assay based on fluorescence cross-correlation spectroscopy.

G protein-coupled receptors (GPCRs) mediate many important physiological functions and are considered as one of the most successful therapeutic target classes for a wide spectrum of diseases. Drug discovery projects generally benefit from a broad range of experimental approaches for screening compound libraries and for the characterization of binding modes of drug candidates. Owing to the difficulties in solubilizing and purifying GPCRs, assay formats have been so far mainly limited to cell-based functional assays and radioligand binding assays. In this study, we used fluorescence cross-correlation spectroscopy (FCCS) to analyze the interaction of detergent-solubilized receptors to various types of GPCR ligands: endogenous peptides, small molecules, and a large surrogate antagonist represented by a blocking monoclonal antibody. Our work demonstrates the suitability of the homogeneous and time-resolved FCCS assay format for a robust, high-throughput determination of receptor-ligand binding affinities and kinetic rate constants for various therapeutically relevant GPCRs.

Studies on deacetoxycephalosporin C synthase support a consensus mechanism for 2-oxoglutarate dependent oxygenases.

Deacetoxycephalosporin C synthase (DAOCS) catalyzes the oxidative ring expansion of penicillin N (penN) to give deacetoxycephalosporin C (DAOC), which is the committed step in the biosynthesis of the clinically important cephalosporin antibiotics. DAOCS belongs to the family of non-heme iron(II) and 2-oxoglutarate (2OG) dependent oxygenases, which have substantially conserved active sites and are proposed to employ a consensus mechanism proceeding via formation of an enzyme·Fe(II)·2OG·substrate ternary complex. Previously reported kinetic and crystallographic studies led to the proposal of an unusual "ping-pong" mechanism for DAOCS, which was significantly different from other members of the 2OG oxygenase superfamily. Here we report pre-steady-state kinetics and binding studies employing mass spectrometry and NMR on the DAOCS-catalyzed penN ring expansion that demonstrate the viability of ternary complex formation in DAOCS catalysis, arguing for the generality of the proposed consensus mechanism for 2OG oxygenases.

Comparison of the substrate selectivity and biochemical properties of human and bacterial γ-butyrobetaine hydroxylase.

2-Oxoglutarate and iron dependent oxygenases have potential for the stereoselective hydroxylation of amino acids and related compounds. The biochemical and kinetic properties of recombinant γ-butyrobetaine hydroxylase from human and Pseudomonas sp. AK1 were compared. The results reveal differences between the two BBOXs, including in their stimulation by ascorbate. Despite their closely related sequences, the two enzymes also display different substrate selectivities, including for the production of (di)hydroxylated betaines, implying use of engineered BBOXs for biocatalytic purposes may be productive.

The enzymes of ß-lactam biosynthesis.

The ß-lactam antibiotics and related ß-lactamase inhibitors are amongst the most important small molecules in clinical use. Most, but not all, ß-lactams including penicillins, cephalosporins, and clavulanic acid are produced via fermentation or via modification of fermented intermediates, with important exceptions being the carbapenems and aztreonam. The desire for more efficient routes to existing antibiotics and for access to new and synthetically challenging ones stimulates continued interest in ß-lactam biosynthesis. We review knowledge of the pathways leading to ß-lactam antibiotics focusing on the mechanisms, structures and biocatalytic applications of the enzymes involved.

Stereoselective preparation of lipidated carboxymethyl-proline/pipecolic acid derivatives via coupling of engineered crotonases with an alkylmalonyl-CoA synthetase.

The trisubstituted enolate- and C-C bond-forming capacities of engineered carboxymethylproline synthases CMPSs are coupled with the malonyl-CoA synthetase MatB to enable stereoselective preparation of 5- and 6-membered N-heterocycles functionalised with alkyl-substituted carboxymethyl side chains, starting from achiral alkyl-substituted malonic acids and L-amino acid semialdehydes. The results illustrate the biocatalytic utility of crotonases in tandem enzyme-catalysed reactions for stereoselective synthesis.

Crotonase catalysis enables flexible production of functionalized prolines and carbapenams.

The biocatalytic versatility of wildtype and engineered carboxymethylproline synthases (CMPSs) is demonstrated by the preparation of functionalized 5-carboxymethylproline derivatives methylated at C-2, C-3, C-4, or C-5 of the proline ring from appropriately substituted amino acid aldehydes and malonyl-coenzyme A. Notably, compounds with a quaternary center (at C-2 or C-5) were prepared in a stereoselective fashion by engineered CMPSs. The substituted-5-carboxymethyl-prolines were converted into the corresponding bicyclic ß-lactams using a carbapenam synthetase. The results demonstrate the utility of the crotonase superfamily enzymes for stereoselective biocatalysis, the amenability of carbapenem biosynthesis pathways to engineering for the production of new bicyclic ß-lactam derivatives, and the potential of engineered biocatalysts for the production of quaternary centers.

γ-Butyrobetaine hydroxylase catalyses a Stevens type rearrangement.

γ-Butyrobetaine hydroxylase (BBOX) is a 2-oxoglutarate and Fe(II)-dependent oxygenase that catalyses the final step of L-carnitine biosynthesis in animals. BBOX catalyses the oxidation of 3-(2,2,2-trimethylhydrazinium)propionate (THP), a clinically used BBOX inhibitor, to form multiple products including 3-amino-4-(methyamino)butanoic acid (AMBA), which is proposed to be formed via a Stevens type rearrangement mechanism. We report the synthesis of AMBA and confirm that it is a product of the BBOX catalysed oxidation of THP. AMBA reacts with formaldehyde, which is produced enzymatically by BBOX, to give a cyclic adduct.

Engaging the public or asking your friends? Analysing science-related crowdfunding using behavioural and survey data.

Science-related crowdfunding enables public engagement with science. However, we know little about citizens engaging with science this way: Who are the people engaging with and donating to science through crowdfunding - and how do they decide how much to give? This study analyses behavioural and survey data from the Swiss crowdfunding platform wemakeit (N = 576). Results illustrate that a small, non-representative segment of the public engages with science through crowdfunding. Compared to the general public in Switzerland, these backers have an above-average education and income. Science-related crowdfunding mainly reaches citizens with an existing interest in science, personal ties to project initiators or the scientific community. The size of backers' donations correlates with perceived personal appeals in campaigns or connections to initiators rather than projects' scientific merit. While science-related crowdfunding thus opens up new avenues for public outreach by the scientific community, its potential for broader public engagement with science seems limited.

Right-sided posttraumatic diaphragmatic rupture and delayed hepatic hernia.

The early diagnosis of posttraumatic diaphragmatic lesions is often difficult which explains the 30 to 50% of non diagnosed cases. This is due to the lack of sensitivity and specificity of the radiographic exams. Missed diaphragmatic lesions results in herniation of abdominal contents into the chest and may be revealed many years from the time of the original trauma. Symptoms such as dyspnea and chronic abdominal complaints are often observed and life-threatening complications, such as visceral strangulation or perforation, contribute to the late morbidity and mortality of the missed injury. Liver herniation is rare and few cases are described in the literature. We report two cases of delayed discovery of the diaphragmatic injury resulting in liver herniation. In one case, there was also an involvement of the duodeno-pancreas. The diagnosis was made 3 and 12 years after the original trauma, respectively, and respiratory embarrassment was the major presenting symptom. The surgical approach was different in the two patients; the first patient was managed by thoracotomy whereas the second patient was treated by laparotomy. The diaphragmatic defect was repaired and reinforced by a prosthetic mesh in the first case. It was closed only by suturing in the second patient. From these two cases, we reviewed the relevant literature and analysed the different approaches for diaphragmatic repair.

Biocatalytic production of bicyclic ß-lactams with three contiguous chiral centres using engineered crotonases.

There is a need to develop asymmetric routes to functionalised ß-lactams, which remain the most important group of antibacterials. Here we describe biocatalytic and protein engineering studies concerning carbapenem biosynthesis enzymes, aiming to enable stereoselective production of functionalised carbapenams with three contiguous chiral centres. Structurally-guided substitutions of wildtype carboxymethylproline synthases enable tuning of their C-N and C-C bond forming capacity to produce 5-carboxymethylproline derivatives substituted at C-4 and C-6, from amino acid aldehyde and malonyl-CoA derivatives. Use of tandem enzyme incubations comprising an engineered carboxymethylproline synthase and an alkylmalonyl-CoA forming enzyme (i.e. malonyl-CoA synthetase or crotonyl-CoA carboxylase reductase) can improve stereocontrol and expand the product range. Some of the prepared 4,6-disubstituted-5-carboxymethylproline derivatives are converted to bicyclic ß-lactams by carbapenam synthetase catalysis. The results illustrate the utility of tandem enzyme systems involving engineered crotonases for asymmetric bicyclic ß-lactam synthesis.

BeerDeCoded: the open beer metagenome project.

Next generation sequencing has radically changed research in the life sciences, in both academic and corporate laboratories. The potential impact is tremendous, yet a majority of citizens have little or no understanding of the technological and ethical aspects of this widespread adoption. We designed BeerDeCoded as a pretext to discuss the societal issues related to genomic and metagenomic data with fellow citizens, while advancing scientific knowledge of the most popular beverage of all. In the spirit of citizen science, sample collection and DNA extraction were carried out with the participation of non-scientists in the community laboratory of Hackuarium, a not-for-profit organisation that supports unconventional research and promotes the public understanding of science. The dataset presented herein contains the targeted metagenomic profile of 39 bottled beers from 5 countries, based on internal transcribed spacer (ITS) sequencing of fungal species. A preliminary analysis reveals the presence of a large diversity of wild yeast species in commercial brews. With this project, we demonstrate that coupling simple laboratory procedures that can be carried out in a non-professional environment, with state-of-the-art sequencing technologies and targeted metagenomic analyses, can lead to the detection and identification of the microbial content in bottled beer.

Survival and prognostic factors after adjuvant 131iodine-labeled lipiodol for hepatocellular carcinoma: a retrospective analysis of 106 patients over 20 years.

OBJECTIVE: Hepatocellular carcinoma (HCC) has high recurrence rate after curative treatment. The aim of the present study was to report our experience with adjuvant use of 131I-lipiodol after curative treatment of HCC in terms of recurrence and survival in a large cohort of patients with a long follow-up. METHODS: All patients treated with 131I-lipiodol after curative treatment of HCC in two French centers from 1991 to 2009 were included in a retrospective cohort study. RESULTS: One hundred and six patients were included. The median (range) follow-up was 6 years (0.3-22). Forty-three patients (41%) had cirrhosis. Recurrence-free survival rates at 1, 2, 5, 10, and 20 years were 73, 57, 40, 30, and 14%, respectively. Cirrhosis was an independent predictive factor of recurrence [RR = 1.18, 95% CI (1.11-3.02), p = 0.019]. Overall, survival rates at 1, 2, 5, 10, and 20 years were 90, 83, 59, 37, and 23%, respectively. Prognostic factors were recurrence [RR = 2.73, 95% CI (1.35-5.54); p = 0.005], age over 60 years (RR = 1.91, 95% CI [1.02-3.61]; p = 0.044), and tumor number over 3 [RR = 3.31, 95% CI (1.25-8.77); p = 0.016]. CONCLUSION: Our results suggest that the effect of 131I-lipiodol after curative treatment of HCC could be related to a beneficial impact on risk factors of early tumor recurrence. This could be evaluated in further studies using modern radioembolization methods.

[Multiple gastro-intestinal stromal tumors (GIST) in a patient with type I neurofibromatosis revealed by chronic bleeding: pre-operative radiological diagnosis]. / Tumeurs stromales gastro-intestinales (GIST) multiples chez un malade atteint d'une maladie de Recklinghausen. Diagnostic radiologique pré-opératoire devant un tableau de fuite sanguine digestive.

Recent studies have pointed out a high incidence of GIST, usually multiple and of small intestinal location, in patients with type I neurofibromatosis. We here report an additional case, revealed by chronic gastro-intestinal bleeding and diagnosed at pre-operative imaging studies. A 56-year-old patient, with known type I neurofibromatosis, was referred to our department for the exploration of chronic gastro-intestinal bleeding during anti-aggregant therapy. Endoscopical examination was negative. Enteroscanner showed the presence of four tumor lesions, 3 in the jejunum and 1 in the ileum. Segmental surgical resections were performed. At histological examination, 2 of among the 3 jejunal lesions were diagnosed as typical GIST, of low risk of malignancy, CD117+, CD34+, whereas the last jejunal and ileal lesions were identified as fibroid tumors. Mutations of c-kit gene and of the gene coding for PDGF-Ralpha were not detected. Post-operative recovery was uneventful; no recurrent bleeding was observed. Our case report underlines the potential role of enteroscanner in the management of patients with type I neurofibromatosis with possible digestive complications. It also emphasizes the importance of an accurate diagnosis of the digestive tumors associated with type I neurofibromatosis: GISTs are frequent in this setting and must not be misdiagnosed as neurofibromas.

Prevalence of anal incontinence in adults and impact on quality-of-life.

OBJECTIVE: To investigate the prevalence of anal incontinence in the general population and in patients consulting gastroenterologist and gynecologist practices in the Rhône Alpes area. METHODS: For the first study a questionnaire was sent to a sample of 2800 people selected randomly from the electoral roll. Another study of patients selected randomly among patients attending gynecology and gastroenterology consultations was performed. A Jorge & Wexner score above or equal to 5 was used to define anal incontinence. RESULTS: For the first study, a total of 706 questionnaires was analyzed: the prevalence of anal incontinence was 5.1% [95% CI: 3.6-7.0] and the scores of each dimension of the SF-12 Health Survey were significantly lower among incontinent people than among continent people. The prevalence was significantly higher for women (7.5% [5.0-10.7]) than for men (2.4% [1.1-4.7]). Eighty-four physicians returned 835 valid questionnaires. The prevalence was 13.1% [10.1-16.6] among patients attending gastroenterology consultations and 5.0% [3.1-7.6] among those attending gynecology consultations. For 84.8% of the incontinent patients, the physician was unaware of the patient's disorder. CONCLUSION: The prevalence figures we obtained coincide with data in the literature. This disorder is common and affects the patient's quality-of-life, but remains underestimated and under-diagnosed.

TIE-2-expressing monocytes are lymphangiogenic and associate specifically with lymphatics of human breast cancer.

In experimental mouse models of cancer, increasingly compelling evidence point toward a contribution of tumor associated macrophages (TAM) to tumor lymphangiogenesis. Corresponding experimental observations in human cancer remain scarce although lymphatic metastasis is widely recognized as a predominant route for tumor spread. We previously showed that, in malignant tumors of untreated breast cancer (BC) patients, TIE-2-expressing monocytes (TEM) are highly proangiogenic immunosuppressive cells and that TIE-2 and VEGFR signaling pathways drive TEM immunosuppressive function. We report here that, in human BC, TEM express the canonical lymphatic markers LYVE-1, Podoplanin, VEGFR-3 and PROX-1. Critically, both TEM acquisition of lymphatic markers and insertion into lymphatic vessels were observed in tumors but not in adjacent non-neoplastic tissues, suggesting that the tumor microenvironment shapes both TEM phenotype and spatial distribution. We assessed the lymphangiogenic activity of TEM isolated from dissociated primary breast tumors in vitro and in vivo using endothelial cells (EC) sprouting assay and corneal vascularization assay, respectively. We show that, in addition to their known hemangiogenic function, TEM isolated from breast tumor display a lymphangiogenic activity. Importantly, TIE-2 and VEGFR pathways display variable contributions to TEM angiogenic and lymphangiogenic activities across BC patients; however, combination of TIE-2 and VEGFR kinase inhibitors abrogated these activities and overcame inter-patient variability. These results highlight the direct contribution of tumor TEM to the breast tumor lymphatic network and suggest a combined use of TIE-2 and VEGFR kinase inhibitors as a therapeutic approach to block hem- and lymphangiogenesis in BC.

Studies on the Glutathione-Dependent Formaldehyde-Activating Enzyme from Paracoccus denitrificans.

Formaldehyde is a toxin and carcinogen that is both an environmental pollutant and an endogenous metabolite. Formaldehyde metabolism, which is probably essential for all aerobic cells, likely proceeds via multiple mechanisms, including via a glutathione-dependent pathway that is widely conserved in bacteria, plants and animals. However, it is unclear whether the first step in the glutathione-dependent pathway (i.e. formation of S-hydroxymethylglutathione (HMG)) is enzyme-catalysed. We report studies on glutathione-dependent formaldehyde-activating enzyme (GFA) from Paracoccus denitrificans, which has been proposed to catalyse HMG formation from glutathione and formaldehyde on the basis of studies using NMR exchange spectroscopy (EXSY). Although we were able to replicate the EXSY results, time course experiments unexpectedly imply that GFA does not catalyse HMG formation under standard conditions. However, GFA was observed to bind glutathione using NMR and mass spectrometry. Overall, the results reveal that GFA binds glutathione but does not directly catalyse HMG formation under standard conditions. Thus, it is possible that GFA acts as a glutathione carrier that acts to co-localise glutathione and formaldehyde in a cellular context.

Influence of rectal prolapse on the asymmetry of the anal sphincter in patients with anal incontinence.

BACKGROUND: Anal sphincter defects have been shown to increase pressure asymmetry within the anal canal in patients with fecal incontinence. However, this correlation is far from perfect, and other factors may play a role. The goal of this study was to assess the impact of rectal prolapse on anal pressure asymmetry in patients with anal incontinence. METHODS: 44 patients, (42 women, mean age: 64 (11) years), complaining of anal incontinence, underwent anal vector manometry, endo-anal ultrasonography (to assess sphincter defects) and pelvic viscerogram (for the diagnosis of rectal prolapse). Resting and squeeze anal pressures, and anal asymmetry index at rest and during voluntary squeeze were determined by vector manometry. RESULTS: Ultrasonography identified 19 anal sphincter defects; there were 9 cases of overt rectal prolapse, and 14 other cases revealed by pelvic viscerogram (recto-anal intussuception). Patients with rectal prolapse had a significantly higher anal sphincter asymmetry index at rest, whether patients with anal sphincter defects were included in the analysis or not (30 (3) % versus 20 (2) %, p < 0.005). Among patients without rectal prolapse, a higher anal sphincter asymmetry index during squeezing was found in patients with anal sphincter defects (27 (2) % versus 19 (2) %, p < 0.03). CONCLUSIONS: In anal incontinent patients, anal asymmetry index may be increased in case of anal sphincter defect and/or rectal prolapse. In the absence of anal sphincter defect at ultrasonogaphy, an increased anal asymmetry index at rest may point to the presence of a rectal prolapse.

Frequency of anal incontinence and results of pelvic viscerography in 291 women with pelvic organ prolapse.

OBJECTIVES: To determine the prevalence of anal incontinence in a population of 291 women with pelvic organ prolapse and evaluate the results of pelvic viscerogram in this situation. MATERIALS AND METHODS: Each patient answered a standardized questionnaire on medical, obstetric and surgical past histories and answers were logged in a database. The viscerograms were performed by a single specialized radiologist. RESULTS: All patients but one were parous. The prevalence of anal incontinence was 26.1%. Stress urinary incontinence and urge urinary incontinence were significantly associated with anal incontinence. No obstetric or surgical risk factor for anal incontinence was demonstrated. Viscerography demonstrated rectoceles (n=86, 29.1%), enteroceles (n=77, 26.5%), cystoceles (n=174, 59.8%), and intra-anal rectal prolapse (n=106, 36.4%). A significant association was found between intra-anal rectal prolapse and anal incontinence. CONCLUSION: Anal incontinence is frequent in patients with pelvic organ prolapse, even more so in the presence of urinary incontinence, and should be investigated by pelvic viscerography. Pelvic floor dysfunction is frequently associated with enteroceles, rectoceles and rectal prolapse. Pelvic viscerograms should be systematically performed in the diagnostic work-up in patients with pelvic organ prolapse when surgical treatment is considered.