Enteral feeding reduces metabolic activity of the intestinal microbiome in Crohn's disease: an observational study.

BACKGROUND/OBJECTIVES: Enteral feeding will induce remission in as many as 80-90% of compliant patients with active Crohn's disease (CD), but its method of action remains uncertain. This study was designed to examine its effects on the colonic microbiome. METHODS/SUBJECTS: Healthy volunteers and patients with CD followed a regimen confined to enteral feeds alone for 1 or 2 weeks, respectively. Chemicals excreted on breath or in faeces were characterised at the start and at the end of the feeding period by gas chromatography/mass spectrometry. RESULTS: One week of feeding in healthy volunteers caused significant changes in stool colour and deterioration in breath odour, together with increased excretion of phenol and indoles on the breath. Feeding for 2 weeks in patients with CD produced significant improvements in symptoms and a decrease in the concentration of C-reactive protein. The faecal concentrations of microbial products, including short-chain fatty acids (SCFAs), and potentially toxic substances, including 1-propanol, 1-butanol and the methyl and ethyl esters of SCFAs, showed significant falls. CONCLUSIONS: A significant change occurs in the production of microbial metabolites after enteral feeding in both healthy volunteers and patients with CD. Many of those detected in CD are toxic and may feasibly lead to the immunological attack on the gut microbiota, which is characteristic of inflammatory bowel disease. The reduction in the production of such metabolites after enteral feeding may be the reason for its effectiveness in CD.

Owners' observations of domestic cats after limb amputation.

Questionnaires were distributed to owners of cats that had undergone limb amputation in the UK, through 1000 veterinary clinics or publications relating to companion cats, or online. Between July 2009 and February 2010, responses were received relating to 234 cats, and data for 204 of these were included in subsequent analyses. The responses received provided data on signalment, aetiology, quality of life, behavioural changes and pain observed in cats after partial or total amputation of a limb. Young male domestic shorthair cats were over-represented in the sample; the most common reason for amputation was a fractured bone, and the hindlimb was almost twice as likely to be amputated as the forelimb. Although 89 per cent of the cats received analgesics/anti-inflammatories after discharge, the owners of 35 per cent of the animals observed some signs of pain during recovery. Eighty-nine per cent of the cats were thought to have regained a 'normal' quality of life as defined by the owner and 94 per cent of the owners stated that they would agree with the decision to amputate the affected limb in a pet if faced with the same decision again.

Sniffing out disease using the artificial nose.

Is there information in the odours that we emit and that circulate around us? More importantly, can doctors gain knowledge of disease by smelling their patients? Machines that emulate the mammalian nose have picked up the scent of several diseases and may drastically change diagnostic procedure.

A ten channel fibre-optic device for distributed sensing of underground hydrocarbon leakage.

With millions of fuel storage tanks and oil pipelines installed around the world, there is inevitably frequent leakage of potentially hazardous hydrocarbons. As many of these installations are below ground, it can often be many years before the extent of the leak is discovered. We have previously reported the development of a sensor for the detection of such subterranean leaks, using infrared reflectometry to interrogate a hydrocarbon sensitive membrane. However, a single sensor cannot provide any information about the flow rate or direction of the leak. This paper describes the extension of the technology to a multi-channel distributed sensing system, using optical fibres capable of distributing the sensors over large subterranean areas. Results are reported from the evaluation of the device, which consisted of monitoring the movement of different hydrocarbons (gasoline, diesel and insulating oil) through a vertical sand-filled vessel.

Investigation of the covalent modification of the catalytic triad of human cytomegalovirus protease by pseudo-reversible beta-lactam inhibitors and a peptide chloromethylketone.

An investigation into the interaction between human cytomegalovirus (HCMV) protease and several beta-lactams, with characterization of the resulting acylenzymes using mass spectrometry, is reported. The time dependence of the inhibitors is highlighted by making comparisons of values obtained for inhibition and acylation. Analysis of inactivated HCMV protease revealed a beta-lactam: protease stoichiometry of 1. Subsequent enzymatic digestion with trypsin, peptide mapping using liquid chromatography coupled with electrospray ionization mass spectrometry and sequencing by nanoelectrospray tandem mass spectrometry (NanoES-MS/MS) allowed the identification of the site of covalent modification and confirmed Ser 132 as the active site hydroxyl nucleophile. Further, treatment of the protease with a peptide chloromethylketone and sequence analysis using NanoES-MS/MS of the alkylated enzyme confirmed His 63 as the active site imidazole nucleophile.

Analysis of latent forms of renin using antibodies raised against the propart segment of human prorenin: validation with representative samples of ovarian cyst and follicular fluids.

Antisera were raised against synthetic peptides from the prosegment of human prorenin. The use of each of these for detection of the appropriate prosegment region of prorenin was validated by development of an ELISA protocol standardised with recombinant prorenin present in culture medium conditioned by myeloma cells transfected with a prorenin expression plasmid. Detection of the respective epitopes in the prosegment required prior exposure of the prorenin in the medium to acid pH in order to partially unfold the prorenin molecule by dislodging the prosegment from the main body of the protein. By these ELISA protocols, the form of latent renin present in representative samples from ovarian cyst and follicular fluids was analysed; one follicular cyst fluid was found to contain full-length prorenin whereas the fluid from a benign cyst and ovarian follicular fluid samples contained the precursor in truncated form.

Inhibition of aspartic proteinases by synthetic peptides derived from the propart region of human prorenin.

1. Five synthetic peptides which together spanned the propart segment of human prorenin were tested for their ability to interact with human renin, pepsin, gastricsin, cathepsin D, cathepsin E, calf chymosin and the aspartic proteinase from Endothia parasitica. 2. While two peptides showed no significant effect with any of the enzymes, a further two were cleaved by several enzymes. 3. Only one (corresponding to the 32P-43P residues in the propart sequence) acted as a weak competitive inhibitor of most of the enzymes.