Search PubMed⌕ Search

Biomedical subjects

C J Ellis

Publications and source records attributed to C J Ellis.

At least 55 records · Page 3Linked to original sources
PubMed1994

Study of constancy of hydrogen-consuming flora of human colon.

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H2-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.

Bacteria↗
PubMed1994

Electrophysiological signs of retinal dopamine deficiency in recently diagnosed Parkinson's disease and a follow up study.

Electrophysiological studies, including electrooculogram (EOG), and simultaneously recorded flash and pattern evoked electroretinograms (FERG and PERG) and visually evoked potentials (FVEP and PVEP) were made in 1988 on 10 newly diagnosed untreated Parkinson's patients at Stage 1 of the Hoehn and Yahr scale. Follow up studies were made on five out of the 10 patients when their disease had progressed to Stage 2 during 1993. The earliest and only sign of abnormality detected in the Stage 1 of Parkinson's patients in 1988 was a delay in the time to reach the peak light rise in the EOG. When the disease had progressed to Stage 2, not only a delay in the time to reach the peak light rise but also a reduction in the amplitude of the peak light rise in the EOG, together with changes in PERG, FERG and PVEPs were demonstrable. These changes observed in PERG, FERG and PVEPs were generally consistent with those reported by previous studies. It is suggested that the reason for the susceptibility of pigment epithelial function to dopamine deficiency in Parkinson's disease may be due to the pigment epithelium being at the extremity of the diffusion pathway from dopamine release sites at the inner plexiform layer.

Adult↗
PubMed1994

Monoplegia following carotid sinus massage.

Serious complications after carotid sinus massage are rare. A case is described of monoplegia complicating carotid sinus massage in an elderly patient without symptoms or signs of cerebrovascular disease. We remind physicians of this potential complication and suggest that alternative therapies be considered prior to the use of carotid sinus massage in this age group.

Aged↗
PubMed1994

Interrelation of strongyloidiasis and tuberculosis.

A 31 year old man from Gambia, resident in the United Kingdom for two years, presented with a two month history of unproductive cough, malaise, weight loss, non-specific abdominal pain, and episodic diarrhoea. Acid alcohol fast bacilli were identified in his sputum, together with Strongyloides stercoralis larvae and Giardia lamblia cysts in his stools. This case illustrates that latent strongyloidiasis can become overt in the presence of tuberculosis, and the diagnosis of strongyloidiasis must be borne in mind in patients who have previously resided in endemic regions.

Adult↗
PubMed1993

Detection of malabsorption of low doses of carbohydrate: accuracy of various breath H2 criteria.

BACKGROUND: Although the accuracy of breath H2 testing to detect malabsorption of small (< 50 g) doses of carbohydrate has never been evaluated, studies suggest that its accuracy is limited by a high prevalence of "H2 nonproducers." The aim of this study was to determine the accuracy of H2 breath testing in the detection of malabsorption of 10 g of carbohydrate. METHODS: In 55 healthy subjects, we determined the ability of breath H2 measurements to distinguish between the ingestion of 10 g of a nonabsorbable carbohydrate (lactulose) and two control meals, a nonabsorbable electrolyte solution or glucose (10 g). RESULTS: The conventional criterion of a 20 ppm increase in breath H2 had 100% specificity but failed to identify lactulose malabsorption in 47% and 24% of subjects at 4 and 8 hours of testing. In contrast, a breath H2 of > 6 ppm at 5 or 6 hours had near perfect specificity and sensitivity. A sum of breath H2 at 5, 6, and 7 hours of > 15 ppm yielded perfect separation between lactulose and control solutions. CONCLUSIONS: True "H2 nonproducers" are extremely rare. Using appropriate criteria, breath H2 testing provides a very accurate means of identifying malabsorption of low doses of carbohydrate.

Adult↗
PubMed1993

Use of metabolic inhibitors to study H2 consumption by human feces: evidence for a pathway other than methanogenesis and sulfate reduction.

Human fecal bacteria produce and consume hydrogen, and consumption rate is a critical determinant of the volume of H2 liberated into the colonic lumen. Two bacterial reactions that have been reported to be major consumers of H2 are methanogenesis and sulfate reduction. To determine the importance of each of these reactions, we measured the disappearance of exogenous H2 during incubation with human fecal homogenates treated with 20 mmol/L 2-bromoethanesulphonic acid (BES), an inhibitor of methanogenesis, and/or 20 mmol/L sodium molybdate (Mo), an inhibitor of sulfate reduction. Four methanogenic and four nonmethanogenic samples consumed an average of 99% and 85%, respectively, of the initial H2 during 22 hours of incubation. With methanogenic homogenates, 36% of the H2 consumption persisted despite inhibition of methanogenesis. Inhibition of sulfate reduction had no effect on the rate of H2 consumption by these eight fecal specimens. The importance of fecal sulfate availability was determined in fecal samples obtained from an additional 14 randomly selected volunteers. Incubation after supplementation with 20 mmol/L sulfate was associated with an increase in sulfide production in four of the samples, and three of these four samples also demonstrated an increased rate of H2 consumption. No such evidence of sulfate reduction was observed in the other 10 homogenates. We conclude that a bacterial reaction other than methanogenesis and sulfate reduction, perhaps the recently described reduction of CO2 to acetate, represents a major metabolic route of H2 disposal in nonmethanogenic feces and a minor, but appreciable, pathway in methanogenic feces.

Feces↗
PubMed1992

A further British case of growth hormone induced Creutzfeldt-Jakob disease.

Transmission of Creutzfeldt-Jakob disease (CJD) from cadaveric growth hormone injections had previously been reported in 7 cases, including one from Britain. As a result, the treatment was abandoned in 1985 and superceded by safer recombinant DNA growth hormone injections. Recent reports now record the number of cases worldwide as 23, but with the incubation period being measured in years, new cases of CJD can still present. We give a detailed report of one of the recent cluster of British cases and aim to highlight the problem to clinicians who may encounter further patients with cadaveric growth hormone induced CJD.

Adult↗
PubMed1992

Generation of cytolytic T cells in individuals infected by Mycobacterium tuberculosis and vaccinated with BCG.

BACKGROUND: Macrophage activation by cytokines provides only a partial explanation of antimycobacterial immunity in man. Because cytolytic T lymphocytes have been shown to contribute to immunity in animal models of intracellular infection, the generation of mycobacterial antigen specific cytotoxic T cells was examined in the peripheral blood of patients with tuberculosis. METHODS: Subjects comprised 36 patients with active tuberculosis (18 newly diagnosed) and 32 healthy volunteers, of whom 25 had had BCG vaccination and seven were Mantoux negative. The ability of purified protein derivative (PPD) stimulated peripheral blood lymphocytes to lyse autologous, mycobacterial antigen bearing macrophages was examined by using a chromium 51 release assay. RESULTS: PPD stimulated lymphocytes from normal, Mantoux positive, BCG vaccinated subjects produced high levels of PPD specific cytolysis, whereas lymphocytes from unvaccinated, uninfected subjects caused little or no cytolysis. The generation of cytolytic T lymphocytes by patients with tuberculosis was related to their clinical state. Those with cavitating pulmonary disease or lymph node tuberculosis generated PPD specific lymphocytes with cytotoxic ability similar to that of those from Mantoux positive control subjects, whereas lymphocytes from patients with non-cavitating pulmonary infiltrates showed poor antigen specific cytolysis. After seven days of stimulation with PPD in vitro, lymphoblasts contained both CD4+ and CD8+ cells. Mycobacterial antigen specific cytolysis was restricted to the CD4+ cell population and was blocked by monoclonal antibodies directed against major histocompatibility class II (MHC) antigens. CONCLUSION: CD4+ cytolytic T cells can lyse autologous macrophages presenting mycobacterial antigen and were found in patients with cavitating pulmonary tuberculosis or tuberculous lymphadenitis and in normal, Mantoux positive control subjects. The ability to generate these T cell responses seems to be a marker for response to mycobacteria and may contribute to tissue damage in tuberculosis. These responses do not provide protective immunity against Mycobacterium tuberculosis but may help in disease localisation.

BCG Vaccine↗
PubMed1991

Competition for hydrogen by human faecal bacteria: evidence for the predominance of methane producing bacteria.

Studies of sludge have shown that some species of sulphate reducing bacteria outcompete methane producing bacteria for the common substrate H2. A similar competition may exist in human faeces where the methane (CH4) producing status of an individual depends on the faecal concentration of sulphate reducing bacteria. To determine if non-methanogenic faeces outcompete CH4 producing faeces for H2, aliquots of each type of faeces were incubated alone or mixed together, with or without addition of 10% H2 and/or 20 mmol/l sulphate. Methane producing faeces consumed H2 significantly more rapidly and reduced faecal H2 tension to a lower value compared with non-methanogenic faeces. The mixture of the two types of faeces yielded significantly more CH4 than CH4 producing faeces alone (mean (SD) 8.5 (1.3) v 2.9 (0.45) mmol/l of homogenate per 24 hours, p less than 0.01). Faecal sulphide concentrations were similar in CH4 producing and non-producing homogenates both before and after 24 hours of incubation. The addition of sulphate to the homogenates did not significantly influence CH4 production or sulphide formation. Our results suggest that in human faeces methane producing bacteria outcompete other H2 consuming bacteria for H2.

Bacteria, Anaerobic↗