Probiotics in gnotobiotic mice: Short-chain fatty acids production in vitro and in vivo

Several bacterial strains are currently used as probioties. Sixteen of them belonging to the genera: Bifidobacterium. Enterococcus. Lactobacillus and Streptococcus, were selected to test short-ehain fatty acids (StJFAs) production in w‘tm and/‘er in viva. The probiotic strains were monoeultivated in specific media and/or monoassoeiated with NMRl-Kl germfree (GF) mice. The individual and total amounts of SCFAs were measured in the media and in the large intestinal content of the ex-GF mice. All the samples were assayed by gas-liquid chromatography. We found that commercially available media contain detectable amounts of acetic and propionic acids. When cultivated in vitro. none of the probiotie strains was able to increase the amounts of SCFAS present in the medium. Rather, a tendency to lowering the concentration of SCFAs following cultivation. was observed. We also found that commercially available laboratory rodents chow contained detectable amount of all SCFAs. When the probiotics were monoinoculated t0 GF animals, nine out of sixteen groups of mice showed higher amount of intestinal SCFAS than in the GF control group. Acetic acid was the dominant one. In all eases. however, the values of the SCFAs were far from those found in conventional mice.The results clearly underline the importance of working with laboratory animals with a known flora. i. e. gnotobiotie animals, when the biochemical “profile" eta prohiotie is worked out

Visualising harms in Randomised Controlled Trial publications: a consensus and recommendations

Objective: To improve communication of harm in RCT publications we identified researchers’ recommendations for visualising harm outcomes. Design: Consensus study evaluating visualisation methods. Setting: 15 UKCRC registered CTUs, an academic population health department, Roche Product Ltd and the BMJ. Participants: Experts in clinical trials: 20 academic statisticians, one industry statistician, one academic health economist, a data graphics designer and two clinicians. Data sources: Visualisations were primarily identified via a methodological review of statistical methods developed specifically to analyse harm outcomes, these were considered alongside visualisations recommended by consensus group members. Interventions: None Main outcomes measured: Consensus for visualisations to recommend achieved over a series of three meetings with participants. Participants reviewed and critically appraised candidate visualisations against an agreed framework. Appraisals were summarised and presented back to participants to inform discussions. After discussions participants voted on whether to endorse each visualisation. Eligibility criteria: Visualisation receiving at least 60% of the available votes were endorsed. Scores marginally below this threshold (50-60%) were revisited for further discussions and votes retaken until a consensus was reached. Results: Twenty-eight visualisations were considered, of which ten are recommended to researchers to consider in publications of main research findings. The choice of visualisations to present will depend on outcome type e.g., binary, count, time-to-event or continuous and the scenario e.g., summarising multiple emerging events or one event of interest. A decision tree to assist trialists decide which visualisations to use is presented. Examples of each endorsed visualisation, along with example interpretation, potential limitations and signposting to code for implementation across a range of standard statistical software are provided. Clinician feedback was incorporated into the explanatory information provided in the recommendations to aid understanding and interpretation. Conclusions: Visualisations provide a powerful tool to communicate harms in clinical trials, offering an alternative perspective to the traditional frequency tables. Increasing the use of visualisations for harm outcomes in clinical trial manuscripts and reports will provide clearer presentation of harm information and thus enable informative interpretation, especially valuable for assessing the profile of harm. Whilst we endorse each of the visualisations presented, we also note their limitations and provide examples of where their use would be inappropriate. Though the decision tree aids the choice of visualisation the statistician and clinical trial team must ultimately decide the most appropriate visualisations for their data and objectives. We recommend trialists continue to examine crude numbers alongside visualisations to fully understand harm profiles

Novel mutations of the growth hormone 1 (GH1) gene disclosed by modulation of the clinical selection criteria for individuals with short stature

Subtle mutations in the growth hormone 1 (GH1) gene have been regarded as a comparatively rare cause of short stature. Such lesions were sought in a group of 41 individuals selected for short stature, reduced height velocity, and bone age delay; a group of 11 individuals with short stature and idiopathic growth hormone deficiency (IGHD); and a group of 154 controls. Heterozygous mutations were identified in all three groups but disproportionately in the individuals with short stature, both with (odds ratio 25.2; 95% CI, 5.1–132.2) and without (odds ratio 3.6; 95% CI, 1.0–12.9) IGHD. Twenty-four novel GH1 gene lesions were found. Thirteen novel missense mutations were characterized by assaying the signal transduction activity of in vitro expressed variants; six (T27I, K41R, N47D, S71F, S108R, and T175A) exhibited a reduced ability to activate the JAK/STAT pathway. Molecular modeling suggested that both K41R and T175A might compromise GH receptor binding. Seven GH variants (R16C, K41R, S71F, E74K, Q91L, S108C, and a functional polymorphism, V110I) manifested reduced secretion in rat pituitary cells after allowance had been made for the level of expression attributable to the associated GH1 proximal promoter haplotype. A further leader peptide variant (L-11P) was not secreted. Eleven novel mutations in the GH1 gene promoter were assessed by reporter gene assay but only two, including a GH2 gene-templated gene conversion, were found to be associated with a significantly reduced level of expression. Finally, a novel intron 2 acceptor splice-site mutation, detected in a family with autosomal dominant type II IGHD, was shown to lead to the skipping of exon 3 from the GH1 transcript. A total of 15 novel GH1 gene mutations were thus considered to be of probable phenotypic significance. Such lesions are more prevalent than previously recognized and although most may be insufficient on their own to account for the observed clinical phenotype, they are nevertheless likely to play a contributory role in the etiology of short stature