Mouse Adaptation of Human Inflammatory Bowel Diseases Microbiota Enhances Colonization Efficiency and Alters Microbiome Aggressiveness Depending on Recipient Colonic Inflammatory Environment

Understanding the cause vs consequence relationship of gut inflammation and microbial dysbiosis in inflammatory bowel diseases (IBD) requires a reproducible mouse model of human-microbiota-driven experimental colitis. Our study demonstrated that human fecal microbiota transplant (FMT) transfer efficiency is an underappreciated source of experimental variability in human microbiota associated (HMA) mice. Pooled human IBD patient fecal microbiota engrafted germ-free (GF) mice with low amplicon sequence variant (ASV)-level transfer efficiency, resulting in high recipient-to-recipient variation of microbiota composition and colitis severity in HMA Il-10-/- mice. In contrast, mouse-to-mouse transfer of mouse-adapted human IBD patient microbiota transferred with high efficiency and low compositional variability resulting in highly consistent and reproducible colitis phenotypes in recipient Il-10-/- mice. Human-to-mouse FMT caused a population bottleneck with reassembly of microbiota composition that was host inflammatory environment specific. Mouse-adaptation in the inflamed Il-10-/- host reassembled a more aggressive microbiota that induced more severe colitis in serial transplant to Il-10-/- mice than the distinct microbiota reassembled in non-inflamed WT hosts. Our findings support a model of IBD pathogenesis in which host inflammation promotes aggressive resident bacteria, which further drives a feed-forward process of dysbiosis exacerbated gut inflammation. This model implies that effective management of IBD requires treating both the dysregulated host immune response and aggressive inflammation-driven microbiota. We propose that our mouse-adapted human microbiota model is an optimized, reproducible, and rigorous system to study human microbiome-driven disease phenotypes, which may be generalized to mouse models of other human microbiota-modulated diseases, including metabolic syndrome/obesity, diabetes, autoimmune diseases, and cancer.

Growth hormone deficiency after childhood bone marrow transplantation with total body irradiation: interaction with adiposity and age

OBJECTIVE

Bone marrow transplantation with total body irradiation (BMT/TBI) has adverse effects on growth, growth hormone status and adiposity. We investigated the GH-IGF-I axis in relation to adiposity.

DESIGN

Cross-sectional case control study.

PATIENTS

BMT/TBI survivors (n = 22) and short stature control participants (n = 19), all GH-naïve or off GH treatment >3 months.

MEASUREMENTS

Auxology, DEXA scans and GH-IGF-I axis investigation: (i) 12-h overnight GH profiles; (ii) insulin tolerance test (ITT); and (iii) IGF-I generation test.

ANALYSIS

auto-deconvolution of GH profile data and comparison of quantitative parameters using ANOVA.

RESULTS

Eighty-two percent of BMT/TBI survivors had growth hormone deficiency (GHD) using ITT. GH profile area-under-the-curve (GH-AUC) was reduced in BMT/TBI survivors vs short stature control participants [geometric mean (range) 209 (21-825) vs 428 (64-1400) mcg/l/12 h, respectively, P = 0·007]. GHD was more marked in those who had additional cranial irradiation (CRT) [ITT peak 1·4 (0·2-3·0) vs TBI only 4·1 (1·1-14·8) mcg/l, P = 0·036]. GHD was more marked at the end of growth in BMT/TBI survivors vs short stature control participants (GH-AUC 551 (64-2474) vs 1369 (192-4197) mcg/l/12 h, respectively, P = 0·011) and more prevalent (9/11 vs 1/9, respectively, P = 0·005). GH profile data were consistent with ITT results in 80% of participants. IGF-I generation tests were normal. BMT/TBI survivors still demonstrated lower GH levels after adjustment for adiposity (fat-adjusted mean difference for GH-AUC 90·9 mcg/l/12 h, P = 0·025).

CONCLUSIONS

GHD was more prevalent in BMT/TBI survivors than expected for the CRT dose in TBI, worsened with time and persisted into adulthood. GHD could not be explained by adiposity. There was no evidence of GH neurosecretory dysfunction or resistance after BMT/TBI.

The intra-push velocity profile of the over-ground racing wheelchair sprint start

The aim of this study was to analyse the first six pushes of a sprint start in over-ground racing wheelchair propulsion. One international male wheelchair athlete (age=28 years; body mass=60.6 kg; racing classification=T4) performed maximal over-ground sprint trials, over approximately 10 m, in his own racing wheelchair fitted with a velocometer. Each trial was filmed at 200 Hz using a "Pan and Tilt" system. Eight trials were manually digitised at 100 Hz. Raw co-ordinate data were smoothed and differentiated using a quintic spline routine. Across the period from pushes one to six the duration of each push cycle decreased (0.82+/-0.02-0.45+/-0.01 s) with the mean duration of the propulsive phase decreasing from 0.62+/-0.02 to 0.21+/-0.01 s and the recovery phase increasing from 0.20+/-0.01 to 0.24+/-0.02 s. The push-rim was contacted progressively closer to top dead centre and released progressively closer to bottom dead centre with each push. The data indicate that peak velocity occurred after release. The main findings of this study support the observation that racing wheelchair sprint propulsion is a complex form of locomotion and cannot be described accurately by using just the established definitions of a propulsive and a recovery phase.

A telemetry-based velocometer to measure wheelchair velocity

The purpose of this paper is to present a telemetry-based velocometer that has the ability to measure wheelchair velocity. Five studies are described which provide measurements of the validity, dynamic response, reliability and resistance of the velocometer.

VALIDITY

a linear relationship was found when velocity calculated from the velocometer was plotted against three test velocities. The average root mean square deviation (ARMSD) was used to compare velocity calculated from the velocometer with velocity calculated by manual digitising at 200Hz. The ARMSD calculated for each test speed from three trials were 0.06+/-0.01, 0.27+/-0.05 and 0.48+/-0.16 ms(-1) at 1, 5 and 9 ms(-1), respectively. Dynamic response: expressed as a percentage of the average mean trial velocity, the ARMSD for the five acceleration and five deceleration trials were 6.5+/-1.8% and 6.9+/-1.2%, respectively. Reliability was assessed from a comparison between mean trial velocity calculated from velocometer output and the speed of the motor used to spin the wheels. Expressed as a percentage of the mean trial velocity, the mean+/-SD of the differences were 0.00+/-0.17%, for the ten disc wheel trials and 0.00+/-0.41%, for the ten spoke wheel trials. Velocometer resistance calculated as a factor of the mechanical resistance of the wheelchair rear wheel spinning in air were -0.50 and -0.91 N, for the disc and spoke wheel, respectively. Velocometer resistance calculated as a factor of the total mechanical resistance of the wheelchair-wheelchair user system were -1.37 and -1.82 N, for the disc and spoke wheel, respectively.

Hatred of the hemiparetic limbs (misoplegia) in a 10 year old child

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Immediate hypersensitivity in patients with cystic fibrosis

Twenty-three out of thirty patients with cystic fibrosis gave strong immediate skin hypersensitivity reaction to a wide variety of allergens. Seventy-five per cent of these had a markedly elevated serum IgE concentration whereas those patients who had negative Type 1 immediate skin reactions also had normal levels of serum IgE. The sputum of those patients with immediate skin reactivity also had positive precipitins to a variety of antigens.