PubMed Health⌕ Search

Biomedical subjects

Russell Foster

Publications and source records attributed to Russell Foster.

8 recordsLinked to original sources
PubMed2006

Calprotectin in microglia from frontal cortex is up-regulated in schizophrenia: evidence for an inflammatory process?

Schizophrenia is associated with a number of pathological changes, including alterations in levels of specific proteins. Calprotectin is a novel 36 kDa calcium-binding protein of the S100 family and appears to be a nonspecific marker of inflammation. Calprotectin has not previously been investigated in brain tissue. Samples of post-mortem brain tissue from Brodmann area 9 were obtained from prefrontal cortex from subjects with schizophrenia, bipolar affective disorder, major depression, and from controls. Calprotectin levels were determined by ELISA. To determine cellular localization, immunocytochemical and fluorescent double-labelling analyses were performed. Exogenous calprotectin was added to retinoic acid-differentiated human SH-SY5Y neuroblastoma cell cultures in order to investigate mechanisms of action of calprotectin. Calprotectin was detectable in all samples, and mean levels were noted to be highest in schizophrenic brains (P < 0.05) and lowest in controls. Levels were intermediate in bipolar affective disorder and major depression. Exogenous calprotectin appeared to induce dendritic extension in SH-SY5Y cell culture in a dose-dependent manner. Calprotectin was found to be localized to microglia. These findings suggest that increased levels of calprotecitn in the brain may reflect inflammatory processes, which play a role in the pathogenesis of major psychiatric disorders. Furthermore, calprotectin may influence dendritic plasticity.

Analysis of Variance↗
PubMed2004

Bowel inflammation as measured by fecal calprotectin: a link between lifestyle factors and colorectal cancer risk.

The mechanisms by which the lifestyle risk factors obesity, physical inactivity, and low fiber intake predispose to colorectal cancer (CRC) are unclear. Chronic bowel inflammation predisposes to malignancy in cases of inflammatory bowel disease. Many lifestyle risk factors for CRC are associated with evidence of systemic inflammation as indicated by circulating levels of C-reactive protein (CRP), but it is unknown how this relates to inflammation at tissue level. Little is known about the degree of bowel inflammation in general population and the factors that affect it. Therefore, we aimed to assess the relation of levels of bowel inflammation in the general population and lifestyle risk factors for CRC, and to additionally assess whether these associations, if present, were attenuated by controlling for evidence of systemic inflammation. Average CRC risk subjects (320) of either sex aged 50-70 were recruited in South London. A stool sample was provided for calprotectin measurement (a marker of bowel inflammation), serum for CRP, and a detailed dietary and lifestyle questionnaire completed. There was a significant positive relationship between fecal calprotectin and increasing age (P = 0.002), obesity (P = 0.04), physical inactivity (P = 0.01), and an inverse relationship with fiber intake (P = 0.02) and vegetable consumption (P = 0.04). The relationship with obesity was attenuated by controlling for serum CRP. Fecal calprotectin levels are associated with lifestyle risk factors for colorectal cancer. Low-level asymptomatic bowel inflammation may be the link between lifestyle and the pathogenesis of CRC, and circulating proinflammatory cytokines may be part of the mechanism for this link.

Age Factors↗
PubMed2003

Emerging role of calprotectin in gastroenterology.

Calprotectin is a calcium and zinc binding protein of the S100 family derived predominantly from neutrophils and monocytes. It is detectable in body fluids and tissue samples and is emerging as a valuable marker in the diagnosis, and the monitoring and determining of the prognosis of commonly encountered gastroenterological conditions. Fecal calprotectin, in particular, has for a long time been regarded as a promising marker of gastrointestinal pathology and has now been established as a routine test in Norway and at several centers in the UK.

Biomarkers↗
PubMed2003

Entrainment of circadian programs.

Of the three defining properties of circadian rhythmicity--persisting free-running rhythm, temperature compensation, and entrainment--the last is often poorly understood by many chronobiologists. This paper gives an overview of entrainment. Where have we been? Where are we now? Whence should we be going? Particular emphasis is given to a discussion of the Discrete vs. Continuous models for entrainment. We provide an integrated mechanism for entrainment from a limit-cycle perspective.

Animals↗
PubMed2002

COX-1 and 2, intestinal integrity, and pathogenesis of nonsteroidal anti-inflammatory drug enteropathy in mice.

BACKGROUND & AIMS: The pathogenesis of nonsteroidal anti-inflammatory drug-induced enteropathy is controversial, but it is thought that cyclooxygenase-1 (COX-1) inhibition is of pivotal importance. We compared small intestinal function and morphology in untreated wild-type, COX-1- and COX-2-deficient mice and the effect of indomethacin, selective COX-1 (SC-560), and COX-2 (celecoxib) inhibition. METHODS: Intestinal permeability ((51)CrEDTA), inflammation (fecal granulocyte marker protein), prostaglandin E(2) (PGE(2)) levels, and macroscopic and microscopic appearances were assessed at baseline and after the drugs. RESULTS: COX-1(-/-) animals were normal except for a 97% decrease in intestinal PGE(2) levels. COX-1(+/+) and COX-1(-/-) animals reacted in a similar way to indomethacin. However, celecoxib, having caused no damage in COX-1(+/+) animals, caused small bowel ulcers in COX-1(-/-) animals. Selective inhibition of COX-1 decreased intestinal PGE(2) levels in COX-2(+/+) and COX-2(-/-) animals by 95%-97%, but caused only small bowel ulcers in the latter group. Dual inhibition of COX-1 and COX-2 in wild-type animals resulted in similar small bowel damage. Between 40% and 50% of untreated COX-2(-/-) animals had increased intestinal permeability and inflammation. Some had ileal ulcers that were distinctively different from indomethacin-induced ulcers. Furthermore, long-term celecoxib administration in wild-type animals was associated with similar damage as in the COX-2(-/-) mice. CONCLUSIONS: COX-1 deficiency or inhibition and short-term COX-2 inhibition are compatible with normal small intestinal integrity. Dual inhibition of the COX enzymes leads to damage similar to that seen with indomethacin. Long-term COX-2 deficiency or inhibition is associated with significant intestinal pathology despite normal intestinal PGE(2) levels, suggesting a role for COX-2 in the maintenance of small intestinal integrity in the mouse.

Animals↗
PubMed2002

Use of surrogate markers of inflammation and Rome criteria to distinguish organic from nonorganic intestinal disease.

BACKGROUND & AIMS: Differentiating symptoms of irritable bowel syndrome (IBS) from those of organic intestinal disease is a familiar problem for physicians. The aim of this study was to assess the sensitivity, specificity, and odds ratios (ORs) of fecal calprotectin, small intestinal permeability, Rome I criteria, and laboratory markers of inflammation (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], blood count) in distinguishing organic from nonorganic intestinal disease. METHODS: A total of 602 new referrals to a gastroenterology clinic who had symptoms suggestive of IBS or organic intestinal disease were studied for these parameters. All patients underwent invasive imaging (barium/endoscopic examination) and other investigations as appropriate, with physicians blinded to the results of fecal calprotectin and intestinal permeability. RESULTS: A total of 263 patients were diagnosed with organic disease and 339 with IBS. At 10 mg/L, the sensitivity and specificity of calprotectin for organic disease were 89% and 79%, respectively, and that of intestinal permeability for small intestinal disease were 63% and 87%, respectively. Sensitivity of positive Rome criteria for IBS was 85% with a specificity of 71%. An abnormal calprotectin test had an OR for disease of 27.8 (95% confidence interval [CI], 17.6-43.7; P < 0.0001) compared with ORs of 4.2 (95% CI, 2.9-6.1; P < 0.0001) and 3.2 (95% CI, 2.2-4.6; P < 0.0001) for elevated CRP and ESR values. An abnormal permeability test gave an OR of 8.9 (95% CI, 5.8-14.0; P < 0.0001) for small intestinal disease. The OR for IBS with positive Rome criteria was 13.3 (95% CI, 8.9-20.0). CONCLUSIONS: Fecal calprotectin, intestinal permeability, and positive Rome I criteria provide a safe and noninvasive means of helping differentiate between patients with organic and nonorganic intestinal disease.

Adolescent↗