Henrik Sandvad Rasmussen

Degradation of Amino Acids to Short-Chain Fatty Acids in Humans: An in Vitro Study

Short-chain fatty acids (SCFA) originate mainly in the colon through bacterial fermentation of polysaccharides. To test the hypothesis that SCFA may originate from polypeptides as well, the production of these acids from albumin and specific amino acids was examined in a faecal incubation system. Albumin was converted to all C2-C5-fatty acids, whereas amino acids generally were converted to specific SCFA, most often through the combination of a deamination and decarboxylation of the amino acids, although more complex processes also took place. This study indicates that a part of the intestinal SCFA may originate from polypeptides, which apparently are the major source of those SCFA (isobutyrate, valerate, and isovalerate) only found in small amounts in the healthy colon. Moreover, gastrointestinal disease resulting in increased proteinous material in the colon (exudation, mucosal desquamation, bleeding, and so forth) may hypothetically influence SCFA production.

Larazotide Acetate for Persistent Symptoms of Celiac Disease Despite a Gluten-Free Diet: A Randomized Controlled Trial

BACKGROUND & AIMS Celiac disease (CeD) is a prevalent autoimmune condition. Recurrent signs and symptoms are common despite treatment with a gluten-free diet (GFD), yet no approved or proven nondietary treatment is available. METHODS In this multicenter, randomized, double-blind, placebo-controlled study, we assessed larazotide acetate 0.5, 1, or 2 mg 3 times daily to relieve ongoing symptoms in 342 adults with CeD who had been on a GFD for 12 months or longer and maintained their current GFD during the study. The study included a 4-week placebo run-in, 12 weeks of treatment, and a 4-week placebo run-out phase. The primary end point was the difference in average on-treatment Celiac Disease Gastrointestinal Symptom Rating Scale score. RESULTS The primary end point was met with the 0.5-mg dose of larazotide acetate, with fewer symptoms compared with placebo by modified intention to treat (n = 340) (analysis of covariance, P = .022; mixed model for repeated measures, P = .005). The 0.5-mg dose showed an effect on exploratory end points including a 26% decrease in celiac disease patient-reported outcome symptomatic days (P = .017), a 31% increase in improved symptom days (P = .034), a 50% or more reduction from baseline of the weekly average abdominal pain score for 6 or more of 12 weeks of treatment (P = .022), and a decrease in the nongastrointestinal symptoms of headache and tiredness (P = .010). The 1- and 2-mg doses were no different than placebo for any end point. Safety was comparable with placebo. CONCLUSIONS Larazotide acetate 0.5 mg reduced signs and symptoms in CeD patients on a GFD better than a GFD alone. Although results were mixed, this study was a successful trial of a novel therapeutic agent targeting tight junction regulation in patients with CeD who are symptomatic despite a GFD. Clinicaltrials.gov: NCT01396213.

Clinical Evaluation of the Lateral Sagittal Infraclavicular Block Developed by MRI Studies

Background and Objectives Lateral sagittal infraclavicular block by single injection has a faster performance time and causes less discomfort than does axillary block by multiple injections. This prospective, descriptive, multicenter study assessed block effectiveness, onset time, and incidence of adverse events and verified the noninvasive measurements from magnetic resonance imaging (MRI). Methods One hundred sixty patients were anesthetized by use of the lateral sagittal infraclavicular block and following the MRI recommendations for needle insertion. Each patient received a mixture that contained equal volumes of ropivacaine 7.5 mg/mL and mepivacaine 20 mg/mL with epinephrine 5 μg/mL, in a total amount that corresponded to 0.5 mL/kg (minimum 30 mL, maximum 50 mL). Block effectiveness (analgesia or anesthesia of all 5 nerves below the elbow after 30 minutes), performance and onset times, needle insertion depth and dorsal angle, twitch type, analgesia of the individual nerves, and incidence of adverse events and complications, as well as patients acceptance, were recorded. Results One hundred forty-three patients (91%) had successful blocks, 12 patients required supplementary nerve blocks in the axilla, 3 patients had total failures of blocks (no forearm analgesia at all), and 2 patients were excluded from the assessments. Median block performance time was 4 minutes (range, 2-10 minutes) and the onset time 20 minutes (range, 10-50 minutes). Plexus nerves were found at a mean depth of 53 mm ± 10 mm and the needle dorsal angle was 23° ± 9°. Four patients experienced painful paresthesias and 3 patients had accidental punctures of axillary vessels. Signs or symptoms of complications (hematoma, local anesthetic toxicity, pneumothorax, or neuropraxias) were not observed. Only 3 patients would prefer general anesthesia in the future. Finger/wrist extension may be an optimal twitch response (P = .14). Conclusions Block effectiveness (91%) and onset time (20 minutes) were satisfactory and comparable to the vertical paracoracoid approach. The low rate of axillary vessel punctures (2%) may be the most important advantage of this block. The needle insertion depth measurements confirmed the MRI findings, but the dorsal angle was steeper than predicted.

Faecal Concentrations and Production Rates of Short Chain Fatty Acids in Normal Neonates

ABSTRACT. Changes in intestinal microbial flora are reflected in the faecal concentrations and production rates of short chain fatty acids. However, since no data on the latter are available in neonates, the aim of this study is to provide information on short chain fatty acids in faeces from normal neonates. Faecal samples were collected immediately after birth (meconium) and on the 4th day of life in 13 healthy, full‐term neonates. The production capacity was evaluated by a faecal incubation system. Concentrations of short chain fatty acids were low in meconium (11.2+3.9 mmol/l (mean±SD)), equivalent to about 10% of the adult level (p<0.01), but increased significantly during the first 4 days of life to 28.4±20.1 mmol/l (p<0.05). The fermentation pattern (i.e. relative composition of different acids) showed differences between adults and neonates, primarily due to a higher proportion of acetate found in the latter. The ratio acetate/propionate/butyrate/other acids was 89/5/5/1 in 4‐day‐old neonates compared to 65/18/11/6 in adults (p<0.001). Our findings correlate well with the postnatal microbial colonization of neonatal colon.

Lack of association of the serotonin transporter gene promoter region polymorphism, 5‐HTTLPR, including rs25531 with cigarette smoking and alcohol consumption

We addressed the question whether 5‐HTTLPR, a variable number of tandem repeats located in the 5′ end of the serotonin transporter gene, is associated with smoking or alcohol consumption. Samples of DNA from 1,365 elderly women with a mean age of 69.2 years were genotyped for this polymorphism using a procedure, which allowed the simultaneous determination of variation in the number of repeat units and single nucleotide changes, including the A > G variation at rs25531 for discrimination between the LA and LG alleles. Qualitative and quantitative information on the womens current and previous consumption of cigarettes and alcohol were obtained using a questionnaire. Genotypes were classified according to allele size, that is, S and L with 14 and 16 repeat units, respectively, and on a functional basis by amalgamation of the LG and S alleles. Data were subjected to regression analyses. These analyses revealed P values for associations between 5‐HTTLPR genotype and alcohol and cigarette consumption in the range from 0.15 to 0.92. On adjustment for age and educational level, significance for the associations of 5‐HTTLPR with the smoking and alcohol consumption measures was not reached. We conclude that 5‐HTTLPR is not an important determinant of smoking behavior and alcohol consumption in elderly women.

Short-chain fatty acids in bowel contents after intestinal surgery

Short-chain fatty acids are produced in the human colon by bacterial fermentation of dietary fibers and other saccharides escaping absorption in the small bowel. Short-chain fatty acid concentrations were determined together with production rates in 6- and 24-h incubations of intestinal outputs from 56 patients with various types of intestinal resections. Concentrations and 6- and 24-h production rates in feces from 9 healthy persons (controls; median +/- SD) were 98.9 +/- 21.4 mmol/L and 17.2 +/- 5.1 and 9.3 +/- 1.5 mmol/L.h, respectively. Colectomized patients with short bowel syndrome had extremely low concentrations (0.8 mmol/L) compared with controls (p less than 10-5), patients with ileostomy (p = 0.003), and ileal reservoirs (p less than 10-5), and showed low 6- and 24-h production rates (1.5 and 0.9 mmol/L.h, respectively; p less than 10-5 vs. controls). Short-chain fatty acids in ileostomic digesta (11.1 mmol/L) were decreased (p = 0.011) compared with outputs from ileal reservoirs (51.5 mmol/L), although production rates were in the same order of magnitude--all below control values (p less than 0.001). Patients partially colectomized and patients with small bowel bypass or short bowel syndrome with preserved colon had normal fecal concentrations with decreased production rates of short-chain fatty acids vs. controls (p less than 0.01). Only minor changes in ratios between individual acids were found. Reciprocal values of short-chain fatty acid concentrations correlated to volumes of outputs from both small intestine (r = 0.86, p less than 10-6) and colon (r = 0.79, p less than 10-6) when results were cumulated. It is concluded that partial resections of colon and the small bowel do not influence the fecal concentration level of short-chain fatty acids as long as colon is not totally resected.

929b Larazotide Acetate, a First In-Class, Novel Tight Junction Regulator, Meets Primary Endpoint and Significantly Reduces Signs and Symptoms of Celiac Disease in Patients on a Gluten-Free Diet: Results of a Multicenter, Randomized, Placebo Controlled Trial

Larazotide Acetate, a First In-Class, Novel Tight Junction Regulator, Meets Primary Endpoint and Significantly Reduces Signs and Symptoms of Celiac Disease in Patients on a Gluten-Free Diet: Results of a Multicenter, Randomized, Placebo Controlled Trial Chao Wang, Henrik Rasmussen, Wendy Perrow, Ciaran P. Kelly, Daniel Le7ffler, Peter Green, Richard N. Fedorak, Anthony J. DiMarino, Premysl Bercik, Joseph A. Murray, Natalie M. Bachir

Short chain fatty acids in inflammatory bowel disease. The effect of bacterial fermentation of blood

An in vitro faecal incubation system was used to investigate how blood added to faeces influences short chain fatty acid (SCFA) production. The result was a change in SCFA pattern from one largely dominated by acetate and propionate to a pattern less dominated by these two acids but with greater amounts of longer and branched SCFA (butyrate, isobutyrate, valerate and isovalerate). Patients with active ulcerative colitis revealed variable concentrations of SCFA in their individual stool specimens, 66% of the samples being outside the 95% confidence interval set by a control group and without any specific trend. The SCFA concentrations were normal in patients with Crohns disease of the colon. The study concludes that the changes in SCFA pattern seen elsewhere in studies on ulcerative colitis could be due to bacterial fermentation of blood either in the colon or in the stools after passing. It cautions against using faecal concentrations in this disease without due regard to the phenomenon of dilution or pollution of the colonic chymus by colonic effusion of blood.

An animal model for teaching ultrasound-guided peripheral nerve blocks.

Many clinicians use a subcutaneous tunnel (with or without a skin bridge) to anchor catheters used in peripheral nerve blocks. Different techniques exist for the subcutaneous tunneling of peripheral nerve catheters for short-term use in postoperative pain control. Among the possible hazards of tunneling are needlesticks to the clinician and also shearing of the catheter by the needle as it approaches the catheter. One way to decrease the previously mentioned hazards is by the use of the block needle’s sheath. The sheaths are open-ended, and many are transparent. Placing an open end of the sheath at the spot where the distal end of the needle will exit the tunnel gives the user a hard point to exert pressure against, while shielding the catheter from the needle tip (Fig. 1). This also gives the user Blonger fingers,[ placing them out of the immediate area of the needle tip. This results in no to minimal skin trauma while using something that is already in the kit. There is less need to collect a sharp instrument to nick the skin at the end of the tunnel. It is hoped that needlesticks and catheter shearing are decreased when this method is used.