Search PubMed⌕ Search

Biomedical subjects

J A Gibson

Publications and source records attributed to J A Gibson.

At least 19 recordsLinked to original sources
PubMed2000

Ice shelf microbial ecosystems in the high arctic and implications for life on snowball earth.

The Ward Hunt Ice Shelf (83 degrees N, 74 degrees W) is the largest remaining section of thick (> 10 m) land-fast sea ice along the northern coastline of Ellesmere Island, Canada. Extensive meltwater lakes and streams occur on the surface of the ice and are colonized by photosynthetic microbial mat communities. This High Arctic cryo-ecosystem is similar in several of its physical, biological and geochemical features to the McMurdo Ice Shelf in Antarctica. The ice-mats in both polar regions are dominated by filamentous cyanobacteria but also contain diatoms, chlorophytes, flagellates, ciliates, nematodes, tardigrades and rotifers. The luxuriant Ward Hunt consortia also contain high concentrations (10(7)-10(8) cm-2) of viruses and heterotrophic bacteria. During periods of extensive ice cover, such as glaciations during the Proterozoic, cryotolerant mats of the type now found in these polar ice shelf ecosystems would have provided refugia for the survival, growth and evolution of a variety of organisms, including multicellular eukaryotes.

Animals↗
PubMed2000

The use of inhaled nitrous oxide for flexible sigmoidoscopy: a placebo-controlled trial.

BACKGROUND AND STUDY AIMS: Flexible sigmoidoscopy is a widely used diagnostic technique which is increasingly being adopted as part of bowel cancer screening programmes. It is conventionally performed without sedation or analgesia, but significant numbers of patients experience mild to moderate discomfort during the procedure. The aim of this study was to assess the usefulness of self-administered nitrous oxide to reduce discomfort during flexible sigmoidoscopy, which may have an effect of improving compliance. PATIENTS AND METHODS: In a double-blind, randomized, placebo-controlled study, 87 patients were enrolled. Of these, 45 received nitrous oxide/oxygen (50% mix) to inhale during the procedure and 42 received oxygen alone. The patients recorded their opinions on the efficacy of the agent in a questionnaire after the examination. The endoscopist recorded the success of the procedure. RESULTS: The groups were well matched for age and sex. Significant reductions in levels of discomfort and increased levels of agreement to undergo the procedure again were noted for the actively treated group (P < 0.05). No significant differences in side effects or success of the procedure were observed. CONCLUSIONS: The addition of self-administered nitrous oxide offered significant benefits in the area of patient discomfort during flexible sigmoidoscopy. The availability of this agent is useful in clinical practice and may enhance compliance with a screening programme.

Anesthetics, Combined↗
PubMed1998

An outbreak of infectious hepatitis in commercially reared ostriches associated with Campylobacter coli and Campylobacter jejuni.

A disease causing high morbidity and mortality was observed in young ostriches from six properties in southeast Queensland, Australia. The disease affected birds from 2-8 weeks of age and was characterised clinically by bright-green urates and pathologically by severe necrotic hepatitis. The liver lesions resembled those of vibrionic hepatitis in other avian species. Campylobacter coli was isolated from the livers of affected ostriches from five of the six properties. Campylobacter jejuni subsp. jejuni was isolated from birds from the remaining property. Pulsed-field gel electrophoresis-based (PFGE) typing of representative isolates indicated that trade of infected birds between farms was an important factor in the spread of C. coli. Phenotypic and genotypic data suggest a clonal variant of the principal outbreak type may account for the remaining cases from which C. coli was found. Conventional biochemical test results and PFGE clearly distinguished the C. jejuni strain isolated from the geographically remote farm from the outbreak of C. coli type. We believe this to be the first definitive report of avian hepatitis associated with C. coli.

Animals↗
PubMed1998

Balsalazide is more effective and better tolerated than mesalamine in the treatment of acute ulcerative colitis. The Abacus Investigator Group.

BACKGROUND & AIMS: Aminosalicylates are widely used in the treatment of ulcerative colitis (UC). Balsalazide is a novel mesalamine prodrug, activated by colonic bacteria. The aim of this study was to compare the efficacy and safety of balsalazide with that of a pH-dependent formulation of mesalamine in active UC. METHODS: A randomized, double-blind study was performed comparing balasalazide, 6.75 g daily, with mesalamine, 2.4 g daily, administered for 4, 8, or 12 weeks to 101 (99 evaluable) patients with symptomatic, sigmoidoscopically verified UC. RESULTS: More patients treated with balsalazide achieved symptomatic remission after 2 (64% [balsalazide] vs. 43% [mesalamine]), 4 (70% vs. 51%), 8 (78% vs. 45%), and 12 weeks (88% vs. 57%) and complete remission (none/mild symptoms, sigmoidoscopy grade 0/1, no rectal steroid use within 4 days) after 4 (38% vs. 12%), 8 (54% vs. 22%), and 12 weeks (62% vs. 37%). Patients taking balsalazide experienced more asymptomatic days (4 weeks, 24% vs. 14%) and achieved the first asymptomatic day more rapidly (median, 10 vs. 25 days). Fewer patients in the balsalazide group reported adverse events (48% vs. 71%); four serious adverse events occurred in the mesalamine group. CONCLUSIONS: Balsalazide is more effective and better tolerated than mesalamine as treatment for acute UC.

Adult↗
PubMed1998

Maintenance of remission of ulcerative colitis: a comparison between balsalazide 3 g daily and mesalazine 1.2 g daily over 12 months. ABACUS Investigator group.

BACKGROUND: Despite widespread use of aminosalicylates as maintenance treatment for ulcerative colitis (UC), patients still report troublesome symptoms, often nocturnally. AIM: To compare the efficacy and safety of balsalazide (Colazide) with mesalazine (Asacol) in maintaining UC remission. METHODS: A randomized, double-blind comparison of balsalazide 3 g daily (1.04 g 5-ASA) and mesalazine 1.2 g daily for 12 months, in 99 (95 evaluable) patients in UC remission. RESULTS: Balsalazide patients experienced more asymptomatic nights (90% vs. 77%, P=0.0011) and days (58% vs. 50%, N.S.) during the first 3 months. Balsalazide patients experienced more symptom-free nights per week (6.4+/-1.7 vs. 4.7+/-2.8; P=0.0006) and fewer nights per week with blood on their stools or on the toilet paper, mucus with their stools or with sleep disturbance resulting from symptoms or lavatory visits (each P < 0.05). Fewer balsalazide patients relapsed within 3 months (10% vs. 28%; P=0.0354). Remission at 12 months was 58%, in both groups. Similar proportions of patients reported adverse events (61% balsalazide vs. 65% mesalazine). There were five serious adverse events (two balsalazide, three mesalazine) and four withdrawals due to unacceptable adverse events (three balsalazide, one mesalazine), of which one in each group was also a serious adverse event. CONCLUSIONS: Balsalazide 3 g/day and mesalazine 1.2 g/ day effectively maintain UC remission and are equally well tolerated over 12 months. At this dose balsalazide prevents more relapses during the first 3 months of treatment and controls nocturnal symptoms more effectively.

Adolescent↗
PubMed1998

A prospective, randomized controlled trial of sedation vs. no sedation in outpatient diagnostic upper gastrointestinal endoscopy.

BACKGROUND AND STUDY AIMS: The majority of gastrointestinal endoscopists in the United Kingdom routinely use intravenous sedation prior to diagnostic upper gastrointestinal endoscopy. We conducted a prospective, randomized controlled clinical trial to help determine whether the use of sedation influences the duration, safety, and tolerance of diagnostic upper gastrointestinal endoscopy. PATIENTS AND METHODS: Adults referred for outpatient diagnostic upper gastrointestinal endoscopy were invited to participate in the study. Patients with a history of previous upper gastrointestinal endoscopy or dysphagia were excluded. Patients were prospectively randomized to sedation with intravenous midazolam (5 mg for those under 65 years or 3 mg for those aged 65 or more), or no sedation. All patients were given topical oropharyngeal anaesthesia with 100 mg lignocaine spray. Outcome measures included duration of procedure, ease of procedure (as assessed by medical and nursing staff), tolerance of procedure (as assessed by patients), and incidence of complications. RESULTS: 100 patients were randomized to receive sedation or no sedation. The two groups were well matched for age, sex, and number of biopsies taken during the procedure. In the non-sedated group, the duration of endoscopy tended to be reduced and the procedure tended to be easier according to the endoscopists' assessment (neither of these observations was significant). The sedated group reported greater comfort for the procedure (P < 0.001), although both groups tolerated the procedure well, and the majority in both groups preferred to have any future procedure repeated in the same manner. There were no serious adverse events in either group. CONCLUSIONS: In patients who are willing to contemplate upper gastrointestinal endoscopy without sedation, the avoidance of sedation may lead to faster and easier endoscopies, without any increased risk of procedural difficulties or adverse events.

Adult↗
PubMed1997

Measles virus serology in Crohn's disease.

BACKGROUND: There is evidence that measles virus infection in early life may predispose to Crohn's disease. AIMS: To examine using serological methods a potential association between measles virus infection in early life and predisposition to Crohn's disease. SUBJECTS: Forty five patients with Crohn's disease and forty five healthy controls were studied prospectively. METHODS: Clinical data were recorded and serum was analysed for measles virus, cytomegalovirus (CMV), adenovirus and herpes simplex virus (HSV) antibody titres by a complement fixation test (CFT), and for measles virus IgM by enzyme linked immunosorbent assay (ELISA). RESULTS: Reciprocal CFT titres for measles virus were lower in patients with Crohn's disease compared with controls (p < 0.05); there was no significant difference in titres for other viruses. None of the subjects studied had a level of measles virus IgM suggestive of acute infection, and there was no significant difference in measles virus IgM levels between patients and controls. The measles virus CFT titres and IgM levels in the patients with Crohn's disease did not correlate with any of the clinical features recorded. CONCLUSION: This study does not provide supportive evidence for a role for measles virus in the aetiology of Crohn's disease.

Adenoviridae↗
PubMed1995

Cutaneous infection with Mycobacterium abscessus.

Cutaneous infection with rapidly growing mycobacteria is uncommon and diagnosis may be difficult. However, the histopathological features are distinctive and may aid diagnosis. The three pathogenic species, Mycobacterium fortuitum, M. chelonae and M. abscessus, show major differences in their antimicrobial sensitivities, and species identification is therefore important. We describe a case of infection with M. abscessus, and discuss the clinical and pathological features of such infections, and approaches to their treatment.

Aged↗
PubMed1992

Short report: comparison of two doses of balsalazide in maintaining ulcerative colitis in remission over 12 months.

In a four-centre prospective double-blind trial, 108 patients with ulcerative colitis in remission were randomized to receive balsalazide in doses of 3 g or 6 g/day for 12 months. The patients were assessed at 3-monthly intervals clinically, sigmoidoscopically and with routine haematology and biochemistry. Remission rates of 77% (3 g/day) and 68% (6 g/day) at 12 months were not significantly different. Intolerance reactions leading to withdrawal from the study occurred in only 9 patients (8%), all occurring in the first 7 weeks of the study. Balsalazide is therefore both highly effective in maintaining remission in ulcerative colitis and well tolerated in both conventional and high dosage (the latter equivalent to 5.5 g/day of sulphasalazine). In this study no distinct advantage in maintenance of remission has been found for the higher dose of balsalazide.

Adult↗
PubMed1990

Behavioral correlates of maternal depressive symptomatology in conduct-disorder children: II. Systemic effects involving fathers and siblings.

This study tested a systemic hypothesis of the relation between maternal depressive symptomatology and the behavior of conduct-disordered children (n = 47) toward their mothers, fathers, and siblings. Maternal symptomatology interacted with the children's behavior toward all family members. Children whose mothers were distressed tended to be more compliant and less aversive toward them than toward their fathers, and the opposite applied to children whose mothers were not distressed. Comparable results were obtained in comparisons of child interactions with mothers and siblings, although in the latter case the children's behaviors differed in absolute magnitude as a function of their interaction partner.

Adolescent↗
PubMed1989

Relationship between radiological classification and the serological and haematological features of untreated pulmonary tuberculosis in Indonesia.

Immunological and metabolic responses were studied in 110 patients with newly diagnosed pulmonary tuberculosis and 32 healthy controls from similar socioeconomic backgrounds. The severity of lung involvement was assessed radiologically, but this was not related to the current features of cell mediated immunity or to those of many aspects of the serological response to Mycobacterium tuberculosis. However, the patients with more extensive pulmonary tuberculosis showed higher titres of IgG2 antibody to whole killed M. tuberculosis and to the ML34 epitope shared by many species of mycobacteria. The patients with more extensive pulmonary tuberculosis showed a more marked metabolic response to infection as manifested by changes in serum levels of acute phase reactant proteins. Accordingly, the metabolic responses are considered to be more likely to prove of value in clinical monitoring of patients for severity of infection, or of reactivation of infection with M. tuberculosis, than immunological responses.

Acute-Phase Proteins↗