388 research outputs found
LIF measurement of the diluting effect of surface waves on turbulent buoyant plumes.
In this paper, the diluting effect of surface waves on a buoyant plume has been measured using a Laser Induced Fluorescence (LIF) technique. The resulting time-averaged, full field concentration maps have allowed quantification of enhanced mixing due to surface waves as well as measurement of other plume parameters
Worsening of cerebral hyperemia by the administration of terlipressin in acute liver failure with severe hepatic encephalopathy
There is increasing evidence that terlipressin is useful in patients with cirrhosis and
hepatorenal syndrome, but there are no data of its use in patients with acute liver
failure (ALF) in whom hepatorenal syndrome is common. Although terlipressin
produces systemic vasoconstriction, it produces cerebral vasodilatation and may
increase cerebral blood flow (CBF). Increased CBF contributes to intracranial
hypertension in patients with ALF. The aim of this study was to evaluate the safety of
terlipressin in patients with ALF with respect to cerebral haemodynamics. Six
successive patients with ALF were electively ventilated for grade IV hepatic
encephalopathy. Patients were monitored invasively and CBF was measured (Kety-
Schmidt technique). Measurements were made before, at 1, 3 hour and 5 hours after
intravenous (single bolus) administration of terlipressin (0.005 mg/kg) )intravenously
(single bolus), median 0.25mg (range 0.2-0.3). There was no significant change in
heart rate, mean arterial pressure or cardiac output. CBF and jugular venous oxygen
saturation both increased significantly at 1 hour (p<0.0=0.016) respectively.
Intracranial pressure increased significantly at 21 hours (p<0=.0.031), returning back
to baseline values at 42 hours. This study shows that administration of terlipressin, at
a dose that did not alter systemic haemodynamicshemodynamics, resulted in
worsening of cerebral hyperemia and intracranial hypertension in patients with ALF
and severe hepatic encephalopathy. These data suggest the need to exercise extreme
caution in the use of terlipressin in these patients in view of its potentially deleterious
consequences on cerebral haemodynamics
One-neutron removal reactions on light neutron-rich nuclei
A study of high energy (43--68 MeV/nucleon) one-neutron removal reactions on
a range of neutron-rich psd-shell nuclei (Z = 5--9, A = 12--25) has been
undertaken. The inclusive longitudinal and transverse momentum distributions
for the core fragments, together with the cross sections have been measured for
breakup on a carbon target. Momentum distributions for reactions on tantalum
were also measured for a subset of nuclei. An extended version of the Glauber
model incorporating second order noneikonal corrections to the JLM
parametrisation of the optical potential has been used to describe the nuclear
breakup, whilst the Coulomb dissociation is treated within first order
perturbation theory. The projectile structure has been taken into account via
shell model calculations employing the psd-interaction of Warburton and Brown.
Both the longitudinal and transverse momentum distributions, together with the
integrated cross sections were well reproduced by these calculations and
spin-parity assignments are thus proposed for B, C, N,
O, F. In addition to the large spectroscopic amplitudes for
the s intruder configuration in the N=9 isotones,B and
C, significant s admixtures appear to occur in the
ground state of the neighbouring N=10 nuclei B and C. Similarly,
crossing the N=14 subshell, the occupation of the s orbital is
observed for O, F. Analysis of the longitudinal and transverse
momentum distributions reveals that both carry spectroscopic information, often
of a complementary nature. The general utility of high energy nucleon removal
reactions as a spectroscopic tool is also examined.Comment: 50 pages, 19 figures, submitted to Phys. Rev.
PROFIT, a PROspective, randomised placebo controlled feasibility trial of Faecal mIcrobiota Transplantation in cirrhosis: study protocol for a single-blinded trial
INTRODUCTION: Patients with advanced cirrhosis have enteric bacterial dysbiosis and translocation of bacteria and their products across the gut epithelial barrier. This culminates in systemic inflammation and endotoxaemia, inducing innate immune dysfunction which predisposes to infection, and development of complications such as bleeding, sepsis and hepatic encephalopathy. This feasibility study aims to assess the safety of administering faecal microbiota transplantion to patients with cirrhosis and explore the effect of the intervention on their prognosis by achieving restoration of a healthy gut microbiome. METHODS AND ANALYSIS: A PROspective, randomised placebo controlled feasibility trial of Faecal mIcrobiota Transplantation is a single-centre, randomised, single-blinded, placebo-controlled study evaluating faecal microbiota transplantation (FMT) against placebo. Patients with advanced but stable cirrhosis with a Model for End-Stage Liver Disease score between 10 and 16 will be recruited. Twenty-four patients will be randomised to FMT plus standard of care (as per our institutional practice) and eight patients to placebo in a ratio of 3:1. Patients will be evaluated at baseline before the study intervention is administered and at 7, 30 and 90 days post-intervention to assess safety and adverse events. FMT/placebo will be administered into the jejunum within 7 days of baseline. The primary outcome measure will be safety and feasibility as assessed by recruitment rates, tolerability and safety of FMT treatment. Results will be disseminated via peer-reviewed journals and international conferences. The recruitment of the first patient occurred on 23 May 2018. ETHICS AND DISSEMINATION: Research Ethics approval was given by the London South East Research Ethics committee (ref 17/LO/2081). TRIAL REGISTRATION NUMBER: NCT02862249 and EudraCT 2017-003629-13
Mucosa-associated invariant T cells link intestinal immunity with antibacterial immune defects in alcoholic liver disease
Background/aims: Intestinal permeability with systemic distribution of bacterial products are central in the immunopathogenesis of alcoholic liver disease (ALD), yet links with intestinal immunity remain elusive. Mucosa-associated invariant T cells (MAIT) are found in liver, blood and intestinal mucosa and are a key component of antibacterial host defences. Their role in ALD is unknown.
Methods/design: We analysed frequency, phenotype, transcriptional regulation and function of blood MAIT cells in severe alcoholic hepatitis (SAH), alcohol-related cirrhosis (ARC) and healthy controls (HC). We also examined direct impact of ethanol, bacterial products from faecal extracts and antigenic hyperstimulation on MAIT cell functionality. Presence of MAIT cells in colon and liver was assessed by quantitative PCR and immunohistochemistry/gene expression respectively.
Results: In ARC and SAH, blood MAIT cells were dramatically depleted, hyperactivated and displayed defective antibacterial cytokine/cytotoxic responses. These correlated with suppression of lineage-specific transcription factors and hyperexpression of homing receptors in the liver with intrahepatic preservation of MAIT cells in ALD. These alterations were stronger in SAH, where surrogate markers of bacterial infection and microbial translocation were higher than ARC. Ethanol exposure in vitro, in vivo alcohol withdrawal and treatment with Escherichia coli had no effect on MAIT cell frequencies, whereas exposure to faecal bacteria/antigens induced functional impairments comparable with blood MAIT cells from ALD and significant MAIT cell depletion, which was not observed in other T cell compartments.
Conclusions: In ALD, the antibacterial potency of MAIT cells is compromised as a consequence of contact with microbial products and microbiota, suggesting that the ‘leaky’ gut observed in ALD drives MAIT cell dysfunction and susceptibility to infection in these patients
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