Short chain fatty acids in human gut and metabolic health.

Evidence is accumulating that short chain fatty acids (SCFA) play an important role in the maintenance of gut and metabolic health. The SCFA acetate, propionate and butyrate are produced from the microbial fermentation of indigestible carbohydrates and appear to be key mediators of the beneficial effects elicited by the gut microbiome. Microbial SCFA production is essential for gut integrity by regulating the luminal pH, mucus production, providing fuel for epithelial cells and effects on mucosal immune function. SCFA also directly modulate host metabolic health through a range of tissue-specific mechanisms related to appetite regulation, energy expenditure, glucose homeostasis and immunomodulation. Therefore, an increased microbial SCFA production can be considered as a health benefit, but data are mainly based on animal studies, whereas well-controlled human studies are limited. In this review an expert group by ILSI Europe's Prebiotics Task Force discussed the current scientific knowledge on SCFA to consider the relationship between SCFA and gut and metabolic health with a particular focus on human evidence. Overall, the available mechanistic data and limited human data on the metabolic consequences of elevated gut-derived SCFA production strongly suggest that increasing SCFA production could be a valuable strategy in the preventing gastro-intestinal dysfunction, obesity and type 2 diabetes mellitus. Nevertheless, there is an urgent need for well controlled longer term human SCFA intervention studies, including measurement of SCFA fluxes and kinetics, the heterogeneity in response based on metabolic phenotype, the type of dietary fibre and fermentation site in fibre intervention studies and the control for factors that could shape the microbiome like diet, physical activity and use of medication.

European Society of ColoProctology: guideline for haemorrhoidal disease.

AIM: The goal of this European Society of ColoProctology project was to establish a multidisciplinary, international guideline for haemorrhoidal disease (HD) and to provide guidance on the most effective (surgical) treatment for patients with HD. METHODS: The development process consisted of six phases. In phase one we defined the scope of the guideline. The patient population included patients with all stages of haemorrhoids. The target group for the guideline was all practitioners treating patients with haemorrhoids and, in addition, healthcare workers and patients who desired information regarding the treatment management of HD. The guideline needed to address both the diagnosis of and the therapeutic modalities for HD. Phase two consisted of the compilation of the guideline development group (GDG). All clinical members needed to have affinity with the diagnosis and treatment of haemorrhoids. Further, attention was paid to the geographical distribution of the clinicians. Each GDG member identified at least one patient in their country who could read English to comment on the draft guideline. In phase three review questions were formulated, using a reversed process, starting with possible recommendations based on the GDG's knowledge. In phase four a literature search was performed in MEDLINE (Ovid), PubMed, Embase (Ovid) and the Cochrane Database of Systematic Reviews. The search was focused on existing systematic reviews addressing each review question, supplemented by other studies published after the time frame covered by the systematic reviews. In phase five data of the included papers were extracted by the surgical resident (RT) and checked by the methodologist (JK) and the GDG. If needed, meta-analysis of the systematic reviews was updated by the surgical resident and the methodologist using Review Manager. During phase six the GDG members decided what recommendations could be made based on the evidence found in the literature using GRADE. RESULTS: There were six sections: (i) symptoms, diagnosis and classification; (ii) basic treatment; (iii) outpatient procedures; (iv) surgical interventions; (v) special situations; (vi) other surgical techniques. Thirty-four recommendations were formulated. CONCLUSION: This international, multidisciplinary guideline provides an up to date and evidence based summary of the current knowledge of the management of HD and may serve as a useful guide for patients and clinicians.

European Society of Coloproctology Core Outcome Set for haemorrhoidal disease: an international Delphi study among healthcare professionals.

AIM: There is considerable heterogeneity in outcomes in studies reporting on the treatment of haemorrhoidal disease (HD). The aim of this study was to develop a Core Outcome Set (COS) for HD in cooperation with the European Society of Coloproctology. METHOD: A Delphi study was performed according to the Outcome Measures in Rheumatology (OMERACT) methodology. In total 38 healthcare professionals and 30 patients were invited to the panel. Previously, 10 outcome domains and 59 outcomes were identified through a systematic literature review. In this study, these domains and outcomes were formed into one questionnaire for healthcare professionals and a separate questionnaire for patients. Sequential questionnaire rounds prioritizing the domains and outcomes were conducted. Panel members were asked to rate the appropriateness of each domain and outcome on a nine-point Likert scale. During a face-to-face meeting, healthcare professionals agreed on the primary and secondary end-points of the COS for HD. Finally, a short survey was sent to the healthcare professionals in order to reach consensus on how the chosen end-points should be assessed and at which time points. RESULTS: The response rate in questionnaire round 1 for healthcare professionals was 44.7% (n = 17). Sixteen out of 17 healthcare professionals also completed the questionnaire in round 2. The response rate for the patient questionnaire was 60% (n = 18). Seventeen healthcare professionals participated in the face-to-face meeting. The questionnaire rounds did not result in a clear-cut selection of primary and secondary end-points. Most domains and outcomes were considered important, and only three outcomes were excluded. During the face-to-face meeting, agreement was reached to select the domain 'symptoms' as primary end-point, and 'complications', 'recurrence' and 'patient satisfaction' as secondary end-points in the COS for HD. Furthermore, consensus was reached that the domain 'symptoms' should be a patient reported outcome measure and should include the outcomes 'pain' and 'prolapse', 'itching', 'soiling' and 'blood loss'. The domain 'complications' should include the outcomes 'incontinence', 'abscess', 'urinary retention', 'anal stenosis' and 'fistula'. Consensus was reached to use 'reappearance of initial symptoms' as reported by the patient to define recurrence. During an additional short survey, consensus was reached that 'incontinence' should be assessed by the Wexner Fecal Incontinence Score, 'abscess' by physical examination, 'urinary retention' by ultrasonography, 'anal stenosis' by physical examination, and 'fistula' by physical examination and MR imaging if inconclusive. During follow-up, the outcome 'symptoms' should be assessed at baseline, 7 days, 6 weeks and 1 year post-procedure. The outcomes 'abscess' and 'urinary retention' should be assessed 7 days post-procedure and 'incontinence', 'anal stenosis' and 'fistula' 1 year post-procedure. CONCLUSIONS: We developed the first European Society of Coloproctology COS for HD based on an international Delphi study among healthcare professionals. The next step is to incorporate the patients' perspective in the COS. Use of this COS may improve the quality and uniformity of future research and enhance the analysis of evidence.

Towards a core outcome set for hemorrhoidal disease-a systematic review of outcomes reported in literature.

PURPOSE: Previously published literature regarding treatment of hemorrhoidal disease (HD) revealed a lack of uniform defined outcomes. These differences between outcomes among studies limit transparency and lead to incomparability of results. The aim of this study was to systematically list the types of outcomes used in HD studies. This list will be used to develop a core outcome set. METHODS: We searched Medline (Pubmed), Embase (OVID), and Cochrane for interventional studies for adult patients with HD. Two authors independently identified and reviewed eligible studies. This resulted in a list of outcomes reported by each clinical trial. All outcomes were categorized using the conceptual framework OMERACT filter 2.0. RESULTS: A total of 34 randomized controlled trials and prospective observational studies were included in this study. A total of 59 different types of outcomes were identified. On average, 5.8 different outcomes (range 2-8) were used per study. The outcomes were structured into three core areas and10 ten domains. The most commonly reported core area was pathophysiological manifestations including the domain symptoms, complications, and recurrence. The most frequently reported outcomes were pain (91%), blood loss (94%), prolapse (71%), and incontinence (56%). There was a high variation in definitions of the common outcomes. And often there was no definition at all. CONCLUSION: This study shows a substantial heterogeneity in the types of outcomes in HD studies. We provided an overview of the types of outcomes reported in HD studies and identified a list of potentially relevant outcomes required for the development of a COS.

Protocol for the development of a Core Outcome Set (COS) for hemorrhoidal disease: an international Delphi study.

PURPOSE: Over the last decade, many studies were performed regarding treatment options for hemorrhoidal disease. Randomised controlled trials (RCTs) should have well-defined primary and secondary outcomes. However, the reported outcome measures are numerous and diverse. The heterogeneity of outcome definition in clinical trials limits transparency and paves the way for bias. The development of a core outcome set (COS) helps minimizing this problem. A COS is an agreed minimum set of outcomes that should be measured and reported in all clinical trials of a specific disease. The aim of this project is to generate a COS regarding the outcome of treatment after hemorrhoidal disease. METHODS: A Delphi study will be performed by an international steering group healthcare professionals and patients with the intention to create a standard outcome set for future clinical trials for the treatment of hemorrhoidal disease. First, a literature review will be conducted to establish which outcomes are used in clinical trials for hemorrhoidal disease. Secondly, both healthcare professionals and patients will participate in several consecutive rounds of online questionnaires and a face-to-face meeting to refine the content of the COS. DISCUSSION: Development of a COS for hemorrhoidal disease defines a minimum outcome-reporting standard and will improve the quality of research in the future.

Integration of a high-NA light microscope in a scanning electron microscope.

We present an integrated light-electron microscope in which an inverted high-NA objective lens is positioned inside a scanning electron microscope (SEM). The SEM objective lens and the light objective lens have a common axis and focal plane, allowing high-resolution optical microscopy and scanning electron microscopy on the same area of a sample simultaneously. Components for light illumination and detection can be mounted outside the vacuum, enabling flexibility in the construction of the light microscope. The light objective lens can be positioned underneath the SEM objective lens during operation for sub-10 µm alignment of the fields of view of the light and electron microscopes. We demonstrate in situ epifluorescence microscopy in the SEM with a numerical aperture of 1.4 using vacuum-compatible immersion oil. For a 40-nm-diameter fluorescent polymer nanoparticle, an intensity profile with a FWHM of 380 nm is measured whereas the SEM performance is uncompromised. The integrated instrument may offer new possibilities for correlative light and electron microscopy in the life sciences as well as in physics and chemistry.

Female-induced increase of host-plant volatiles enhance specific attraction of aphid male Dysaphis plantaginea (Homoptera: Aphididae) to the sex pheromone.

All aphid species studied so far share the same sex pheromone components, nepetalactol and nepetalactone. Variation by different enantiomers and blends of the two components released by different aphid species are limited and can only partially explain species-specific attraction of males to females. While some host-plant odours are known to enhance specific attraction of aphid species, herbivore-induced plant volatiles that synergise attractiveness to the sex pheromone are unknown. Here, we demonstrate that for the host-alternating rosy apple aphid (Dysaphis plantaginea (Passerini)) specificity of attraction of males to females is triggered by female-induced tree odours in combination with a 1:8 ratio of (4aS,7S,7aR)-nepetalactone and (1R,4aS,7S,7aR)-nepetalactol. Female aphid infestation induces increased release of four esters (hexyl butyrate, (E)-2-hexenyl butyrate, (Z)-3-hexenyl 3-methylbutyrate and hexyl 2-methylbutyrate) from apple leaves. Two different combinations of three esters applied in a 1:1:1 ratio increase the number of male D. plantaginea and decrease the number of other aphid species caught in water traps in the presence of the pheromone components. The ester blend alone was not attractive. Combination of the pheromone blend with each single ester was not increasing attraction of male D. plantaginea. The demonstration that sexual aphid species use herbivore-induced plant volatiles as a species-specific attractant for mate finding adds a new dimension to our understanding of insect species using or manipulating chemical cues of host plants for orientation.

The Dutch-Belgian beamline at the ESRF.

A brief description is given of the design principles and layout of the Dutch-Belgian beamline at the ESRF. This beamline optimizes the use of the available bending-magnet radiation fan by splitting the beam into two branches, each accommodating two experimental techniques.

Central venous catheter associated thrombosis of major veins: thrombolytic treatment with recombinant tissue plasminogen activator.

OBJECTIVE: Major thromboses can occur in the venous system in association with central venous catheters. This usually necessitates removal of the catheter. METHODS: The effectiveness of low dose recombinant tissue type plasminogen activator (rt-PA) in combination with heparin was assessed in patients with central venous catheter associated thrombosis. RESULTS: In five patients, all suffering from cancer, a 5-7 day continuous infusion resulted in complete lysis of the thrombus without complications in three. In the other two patients moderately severe haemorrhage was observed with only partial lysis, of the thrombus. CONCLUSIONS: The infusion of heparin and rt-PA is potentially effective in thrombosis related to use of central venous catheters, but the risk of haemorrhage is not inconsiderable.

Zatebradine: pharmacokinetics of a novel heart-rate-lowering agent after intravenous infusion and oral administration to healthy subjects.

Zatebradine (1; UL-FS 49 CL; 1,3,4,5-[tetrahydro-7,8-dimethoxy-3-[3-[ [2-(3,4-dimethoxyphenyl)ethyl]methylamino]propyl]-2H-3-benzazepin- 2-on- hydrochloride) is the proposed INN name for a nonchiral, novel, specific heart-rate-lowering drug that is suitable for the treatment of stable angina pectoris. The pharmacokinetics of 1 and of total radioactivity in healthy volunteers (n = 6) were determined after intravenous infusion and oral administration of an experimental drug solution containing 7.5 mg (1.85 MBq) of 14C-labeled drug. Concentrations in plasma and urine were measured by a specific, sensitive, reversed-phase automated high-performance liquid chromatography system with fluorimetric detection at 285 nm Ex, 315 nm Em and by liquid scintillation counting. Recovery of total radioactivity was 89.8 +/- 2.3% (infusion) and 92.2 +/- 3.0% (oral). Renal elimination of total radioactivity was 62.5 +/- 2.0% (infusion) and 48.8 +/- 3.1% (oral). After intravenous infusion and oral administration, 27.3 +/- 2.4 and 43.4 +/- 3.9%, respectively, of the administered dose was eliminated in the feces. Absorption, based on renal excretion of total radioactivity following oral and intravenous dosing, was 79.2 +/- 15.3% (mean +/- standard deviation). Unchanged parent drug contributed 28.4 +/- 5.8% (infusion) and 12.4 +/- 3.7% (oral) of the dose to renal excretion. Zero to three minutes after cessation of the 20-min infusion, the maximum concentration of parent drug in plasma was 161.9 +/- 70.9 ng/mL. After oral administration, a mean peak concentration in plasma of 24.3 +/- 6.7 ng/mL (0.5-3 h postadministration) was reached. Data regarding levels of 1 in plasma could be adequately fitted with an open, two-compartment model.(ABSTRACT TRUNCATED AT 250 WORDS)

Low allergenicity of clonidine impedes studies of sensitization mechanisms in guinea pig models.

During clinical trials, a clonidine transdermal device has been found to induce clonidine-specific allergic contact dermatitis in up to 25% of patients during a treatment period of 1 year. Using 3 different guinea pig strains, development was attempted of an experimental guinea pig model that would allow for in-depth studies into the mechanism of sensitization, and a possible role of transdermal device components. Transient low-level clonidine allergy could be obtained only in a minority of animals, with severe sensitization procedures departing from epicutaneous applications, combined with intradermal (adjuvant) FCA injections. Sensitization was not potentiated by additional booster procedures, including cyclophosphamide pretreatment, nor any of the putative cofactors (UV-treatments, C. parvum or acetaldehyde involvement) studied. These results suggest that the persistent skin contacts in man, with transdermal devices for sustained drug delivery, generate unique conditions favouring the development of allergic contact dermatitis, which are difficult to mimic in experimental animal models. Thus, clinical allergy may develop even to extremely weak sensitizing drugs that can be safely used orally, and escape most currently available predictive contact allergy animal models. Clinical studies remain unavoidable for studying factors that may reduce sensitization rates to more acceptable levels.

Suppressive effects of transdermal clonidine administration on contact hypersensitivity reactions in guinea pigs.

In the present study, immunopharmacological effects of clonidine-TTS on allergic contact dermatitis (ACD) to non-related, established contact sensitizers were investigated in guinea pigs. First, to evaluate the hypotensive effect of clonidine-TTS in guinea pigs, intra-arterial blood pressure was recorded. After 4 days of treatment with one (or two) TTS per animal, a reduction of arterial blood pressure from 71 +/- 1 to 51 +/- 2 mm Hg was observed. We subsequently assessed the effects of clonidine-TTS on contact hypersensitivity reactions to 2,4-dinitrochlorobenzene (DNCB) and 4-ethoxymethylene-2-phenyl-oxazolone (Ox). This study indicates that clonidine-TTS suppressed the elicitation of contact hypersensitivity reactions. The observed immunosuppressive effect of clonidine may account for the relatively weak hypersensitivity reactions to this drug in experimental animal studies. Further studies are needed to determine whether such findings are of relevance to the clinical use of clonidine in patient populations.

Pharmacokinetics of transdermally delivered clonidine.

We detail a series of pharmacokinetic investigations to determine the dose linearity, the effect of site of application, the duration of steady-state plasma concentrations, and the effect of chronic application when clonidine is administered transdermally. Dose linearity was assessed in six subjects with normotension after application of increasing sizes of transdermal clonidine systems (3.5, 7.0, and 10.5 cm2 size) to the upper outer arm. Of the six subjects studied, five had linear relationships between clonidine plasma concentrations at steady state and system size of greater than 0.975; in the sixth subject the correlation was greater than 0.90. The mean steady-state plasma concentrations with 3.5, 7.0, and 10.5 cm2 systems were 0.39, 0.84, and 1.12 ng/ml, respectively. The influence of site and duration of application on the absorption of transdermal clonidine was studied in eight subjects with normotension by use of the 3.5 cm2 system. The mean steady-state plasma concentration over the time interval from 3 to 7 days after application to the arm or to the chest did not significantly differ. When a system was left on the chest or arm for a total of 11 days (4 days beyond the recommended time to change systems), the plasma concentrations of seven of eight subjects with application to the arm and of six of eight subjects with application to the chest remained constant through day 11. The influence of consecutive applications of 3.5 cm2 transdermal clonidine systems on steady-state plasma clonidine concentrations was also studied in eight subjects with normotension over an 11-day period.(ABSTRACT TRUNCATED AT 250 WORDS)

Phase I study of recombinant human interferon alpha-2C in patients with chemotherapy-refractory malignancies.

Twenty-two patients with advanced haemopoietic and other malignancies were treated intramuscularly with recombinant interferon-alpha 2C in a daily escalating dose. The most common side-effects were flu-like symptoms. Two patients showed severe neurotoxicity, which was completely reversible in 1 case. Doses above 30 X 10(6) IU/day were poorly tolerated and could only be achieved in a minority of the patients. Objective tumour responses were documented in malignant lymphomas, hairy cell leukaemia, and renal cell carcinoma.

Lack of serological relationship between the 35K nonstructural protein of alfalfa mosaic virus and the corresponding proteins of three other plant viruses with a tripartite genome.

Alfalfa mosaic virus RNA 3 was translated in the mRNA-dependent rabbit reticulocyte cell-free system. The 35K translational protein was partly purified and used to raise antibodies. The antibodies obtained reacted with the 35K protein directed by AMV RNA 3 but not with the corresponding proteins directed by RNAs from three other viruses with a tripartite genome (tobacco streak, cucumber mosaic, and brome mosaic).

Translation of alfalfa-mosaic-virus RNA 1 in the mRNA-dependent translation system from rabbit reticulocyte lysates.

Translation of alfalfa mosaic virus (AMV) RNAs in the mRNA-dependent rabbit reticulocyte cell-free system was examined using different RNA concentrations. The pattern of products synthesized under the direction of AMV RNA 2, 3 and 4 was not or almost not influenced by their concentration. However, depending on the RNA 1 concentration either a very large protein of Mr 115,000 or a mixture of two smaller proteins, Mr 58,000 and 62,000 respectively, was formed. These three proteins represent overlapping peptide chains with identical N-termini. Addition of the cap analogue 7-methylguanosine 5'-monophosphate (m7GMP) or AMV RNA 3 stimulated the production of the 115,000-Mr protein at the expense of the 58,000-Mr and 62,000-Mr proteins. Both m7GMP and RNA 3 probably reduce the active concentration of RNA 1 by competing for (a) cellular component(s) necessary for translation. These experimental results suggest that the rate of translation beyond the C termini of the 58,000-Mr and 62,000-Mr proteins is reduced or completely inhibited owing to the limited availability of the succeeding tRNA(s).