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Biomedical subjects

J R Lambert

Publications and source records attributed to J R Lambert.

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

Changes in serum carotenoids in subjects with colorectal adenomas after 24 mo of beta-carotene supplementation. Australian Polyp Prevention Project Investigators.

The effect of beta-carotene supplementation on major serum carotenoid fractions (lutein/zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, and beta-carotene) was investigated in 224 people with colorectal adenomas (139 men, 85 women) recruited for the Australian Polyp Prevention Project (APPP). Each subject was randomly assigned to take either 20 mg beta-carotene/d or placebo over 24 mo. Besides the expected increase in serum concentration of beta-carotene (1073% in men, 839% in women), lycopene (176% in men) and alpha-carotene (211% in men and 166% in women) concentrations were also increased after body mass index, baseline concentration, change in respective carotenoid intake, and other confounding factors were adjusted for. The increase in serum concentrations of these carotenoids after beta-carotene supplementation suggests that beta-carotene may interact biologically with other carotenoids and such interaction would need to be taken into consideration when the protective effect of beta-carotene supplementation for cancer or other diseases is examined.

Adenoma↗
PubMed1994

Fibre optic confocal imaging (FOCI) for subsurface microscopy of the colon in vivo.

Fibre optic confocal imaging (FOCI) is a new type of microscopy which has been recently developed (Delaney et al. 1993). In contrast to conventional light microscopy, FOCI and other confocal techniques allow clear imaging of subsurface structures within translucent objects. However, unlike conventional confocal microscopes which are bulky (because of a need for accurate alignment of large components) FOCI allows the imaging end to be miniaturised and relatively mobile. FOCI is thus particularly suited for clear subsurface imaging of structures within living animals or subjects. The aim of the present study was to assess the suitability of using FOCI for imaging of subsurface structures within the colon, both in vitro (human and rat biopsies) and in vivo (in rats). Images were obtained in fluorescence mode (excitation 488 nm, detection above 515 nm) following topical application of fluorescein. By this technique the glandular structure of the colon was imaged. FOCI is thus suitable for subsurface imaging of the colon in vivo.

Animals↗
PubMed1993

Tricho-rhino-phalangeal syndrome type I (TRP I) due to an apparently balanced translocation involving 8q24.

Tricho-rhino-phalangeal (TRP) syndromes type I and II are caused by a defective gene located on chromosome 8q24.1. We report a family with 2 sibs affected with TRP type I in combination with an apparently balanced chromosome (8;18) translocation involving 8q24.11. It is very likely that the 8q24 translocation breakpoint is physically linked to the TRP gene(s), thereby facilitating future efforts to clone the TRP gene(s).

Abnormalities, Multiple↗
PubMed1993

Early detection of protein depletion in alcoholic cirrhosis: role of body composition analysis.

BACKGROUND: Malnutrition is common in alcoholic cirrhosis. Bedside nutritional assessment techniques may be unreliable in patients with chronic liver disease. The aim of this study was to quantify changes in body composition and compare methods for measuring body composition in alcoholic cirrhosis. METHODS: Thirty-eight men with alcoholic cirrhosis were compared with 16 age-matched healthy men. Body composition was assessed using anthropometry and bioelectrical impedance to determine fat-free mass and body fat, deuterium oxide dilution to measure total body water, in vivo neutron activation analysis to measure total body protein, and dual energy x-ray absorptiometry to measure bone mineral content and total body fat mass. RESULTS: With increasing severity of cirrhosis, total body water increased, whereas total body protein decreased with a significant decrease in serum albumin levels. Total body protein levels, expressed as an index, were a more sensitive indicator of protein depletion than serum albumin levels. When patients were assessed by anthropometry and bioelectrical impedance for fat-free mass, there was no reduction compared with controls. CONCLUSIONS: Anthropometry and bioelectrical impedance do not accurately reflect changes in body composition associated with chronic liver disease. Quantification of body composition changes in alcoholic cirrhosis requires the use of direct methods such as in vivo neutron activation analysis, dual energy x-ray absorptiometry, or deuterium oxide dilution.

Adult↗
PubMed1993

Comparison of commercial diagnostic tests for Helicobacter pylori antibodies.

A number of serological tests measuring the presence of Helicobacter pylori-specific serum immunoglobulin G (IgG) are now commercially available. The aim of this study was to evaluate the clinical accuracy of five commercial H. pylori antibody tests: GAP-IgG (Biomerica), HELpTEST (AMRAD, Kew, Victoria, Australia), HELICO-G (Porton Cambridge), Pyloriset (Orion Diagnostica), and ROCHE (Roche Diagnostics). A total of 162 subjects presenting for routine upper endoscopy were studied. H. pylori was diagnosed if culture, histology, or both were positive. Ten milliliters of venous blood was collected at the time of endoscopy for serological assessment. The sensitivity and specificity of each test (GAP-IgG, HELpTEST, HELICO-G, Pyloriset, and ROCHE) were as follows: 83 and 79%, 92 and 77%, 86 and 65%, 89 and 56%, and 98 and 69%, respectively. Positive and negative predictive values were 97 and 83%, 90 and 91%, 76 and 83%, 68 and 84%, and 86 and 97%, respectively. The specificity of most tests increased by approximately 10% when sera from subjects less than 45 years old were examined. The number of sera falling into the grey zone for each test (an indeterminate result with respect to H. pylori status) varied between 2.5 and 19%. This study highlights the need for all serological kits to be independently evaluated on the population to be studied by testing against a microbiologically defined panel of H. pylori-positive and -negative sera.

Adolescent↗
PubMed1993

The role of Helicobacter pylori in nonulcer dyspepsia. A debate--for.

Nonulcer (functional) dyspepsia is a common heterogenous disease resulting in upper gastrointestinal tract symptoms. Evidence would support that a subset of this disease is caused by H. pylori-induced gastritis. Despite the conflicting evidence, most studies evaluating H. pylori clearance and eradication, particularly the long-term studies, have observed clinical improvement in most subjects. Hill's concepts to distinguish causal from noncausal associations of an agent to a specific disease include the strength of association, consistency, specificity, temporality, biologic gradient, plausibility, coherence, experimental evidence, and analogy. There is considerable criticism of these nine aspects of epidemiologic evidence to judge whether an association is causal. These epidemiologic criteria to support that an association is causal are inappropriate when applied to H. pylori and NUD. First, the disease definition, based on clinical criteria, is imprecise, with poorly defined end points and considerable individual variability in interpretation. Second, it would appear that the cause is multifactorial, and thus, evaluation of one etiologic agent is inappropriate. In view of the potential factors to cause NUD, a scheme of treatment with a subset of eradication of H. pylori if present is advocated (Fig. 1). It is suggested that, because of the conflicting data in this area, subjects be entered into clinical trials, with eradication of H. pylori evaluated and long-term follow-up of symptoms accurately monitored.

Dyspepsia↗
PubMed1991

Low-dose antacids and nonsteroidal anti-inflammatory drug-induced gastropathy in humans.

Gastroduodenal injury induced by nonsteroidal anti-inflammatory drugs (NSAIDs) is common. As yet, the ideal means to prevent NSAID-related mucosal injury remains controversial. Antacids are effective agents in treating gastric and duodenal ulcers unrelated to NSAIDs. The aim of this study was to assess the ability of a low-dose antacid to prevent NSAID injury in humans. Fifty healthy human volunteers were studied using a randomized, double-blind, placebo controlled, crossover design. After initial endoscopy, subjects were randomized to either Maalox TC (1 tablet q.i.d., acid neutralizing capacity of 104 mEq/day) or identical placebo while receiving 500 mg of naproxen b.i.d. for 21 days. After this period, a second endoscopy was performed to count antral and duodenal erosions and to evaluate symptoms and compliance with study medications. A 21-day washout period ensued, followed by a third endoscopy to insure a return to endoscopically normal mucosa. Subjects then crossed over into the alternate treatment arm for a further 21 days, followed by a fourth endoscopy to assess erosions. Forty subjects completed the study. Subjects receiving Maalox TC developed a significantly greater number of gastric erosions than did those on placebo. While this result was unforeseen, it is supported by statistical analysis and may have clinical relevance in regard to short-term NSAID therapy.

Adolescent↗
PubMed1991

Clinical indications and efficacy of colloidal bismuth subcitrate.

Colloidal bismuth subcitrate (CBS; DeNol) has been studied in clinical trials investigating the treatment of duodenal and gastric ulcer, non-ulcer dyspepsia, duodenitis, non-steroidal anti-inflammatory drug (NSAID)-induced disease, and Helicobacter pylori-induced gastroduodenitis. Healing rates for duodenal ulcer with CBS are significantly better than with placebo and are similar to results obtained with cimetidine or ranitidine. CBS is significantly better in the treatment of duodenal ulcer resistant to standard doses of H2 antagonists than increased doses of H2 antagonists. Duodenal ulcer relapse at 12 months after initial healing with CBS is significantly less than with H2-antagonist therapy. Ulcer healing with CBS is not influenced by smoking. H. pylori eradication with CBS appears to have little effect in ulcer healing but is of major importance in preventing ulcer relapse. CBS is effective in combination with antibiotics in eradicating H. pylori-associated gastritis. In gastric ulcer disease CBS therapy resulted in significant healing advantages over placebo and was comparable to treatment with cimetidine and sucralfate. CBS has been shown to be effective in the treatment of erosive duodenitis. The role of CBS in treatment of non-ulcer dyspepsia and NSAID-induced damage awaits further clinical studies.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1990

In-vivo anti-reflux and raft properties of alginates.

The comparative efficacy of two alginate-containing anti-reflux preparations (Gaviscon, Algicon) was assessed in a single blind crossover study of 20 patients with gastro-oesophageal reflux disease. The clinical efficacy study was preceded by two studies in healthy volunteers to assess the intragastric effects of Algicon and Gaviscon by pH measurement, endoscopic visualization and gamma scintigraphy. Algicon and Gaviscon were shown to form a raft in the fasting and fed human stomach, with Algicon alone having a potent antacid effect below and within the raft. Both Algicon and Gaviscon liquids significantly reduced the frequency and severity of reflux symptoms from baseline when given at their recommended doses (10 ml and 20 ml four times daily, respectively). There were no significant differences between Algicon and Gaviscon, although 12 patients preferred Algicon (vs 5 for Gaviscon) for control of reflux symptoms. It was concluded that both Algicon and Gaviscon were effective for the symptomatic control of gastro-oesophageal reflux disease.

Adult↗
PubMed1989

Campylobacter pylori--a role in non-ulcer dyspepsia?

Non-ulcer dyspepsia (NUD) is a common complaint in which no systematic illness or organic proximal alimentary tract disease can be identified. The pathophysiology of NUD is probably heterogeneous. Eighty-two subjects with NUD were studied in a prospective randomized placebo-controlled study to assess the efficacy of colloidal bismuth subcitrate (CBS) chewable tablets at a dose of four tablets daily for 1 month. The role of Campylobacter pylori and associated histological gastritis was evaluated. Sixty-one percent of NUD patients had C. pylori in the gastric antrum compared with 25% of age-matched controls. C. pylori was associated with acute and chronic inflammation (P less than 0.001) in the antrum. C. pylori was cleared in 59% of CBS-treated subjects compared with only 4% placebo (P less than 0.05). Both acute and chronic inflammation improved in subjects cleared of bacteria. Clearance of C. pylori and histological improvement was associated with a significant decrease in symptoms. In C. pylori negative subjects improvement in symptoms occurred in both the placebo and active treatment groups. This study would suggest that C. pylori and associated histological gastritis may play a role in non-ulcer dyspepsia.

Adult↗