ABSTRACT
A systematic review is a carefully planned and conducted study designed to answer a specific focused clinical question. A systematic review differs from the frequently encountered narrative review article. Systematic review must be completed using a prespecified methodology. The reader must ask eight important questions when reading a systematic review: (i) did the review address a focused clinical question (ii) is it likely that important, relevant studies are missed (iii) were the inclusion criteria used to select appropriate articles (iv) was the validity of the included studies assessed (v) were the assessments of studies reproducible (vi) were the results similar from study to study (vii) what were the overall results and how precise are they and (viii) will the results help in caring for patients. The article also provides sources for systematic reviews.
Subject(s)
Evidence-Based Medicine , Meta-Analysis as Topic , Periodicals as Topic , Research , Review Literature as TopicABSTRACT
A differential distribution of sialyltransferase (ST) in different regions of intestine has been shown. Jejunum and ileum homogenates from rats showed almost exclusive presence of alpha-2-3 ST (to Gal in Gal beta-1-4GlcNAc and/or to Gal in Gal beta-1-3GalNAc). In contrast, colon homogenates showed the presence of both alpha-2-3 ST (as above) and alpha-2-6 ST. Incubation of intestinal slices in presence of heat-inactivated horse serum (HHS) showed a time- and temperature-dependent secretion of soluble ST into the medium. Both jejunum and ileum slices showed high rates of secretion of alpha-2-3 ST. Colon slices, though rich in alpha-2-6 ST, secreted only alpha-2-3 ST. Colchicine, an anti-mitotic drug, injected into rats caused about 10-fold increase of the serum ST level. Jejunum slices from colchicine-treated rats showed an increased secretion of alpha-2-6 ST, suggesting that intestine undergoes a change in the expression of normal secretion of alpha-2-3 ST to a secretion of alpha-2-6 ST. The secretion of ST from incubated intestinal slices was inhibited by heparin. Certain protein factors (anti-proteases) in HHS bind to heparin-sepharose column and these protein factors are responsible for causing the secretion of ST into the medium. It has also been found that a supernatant fraction of the colon homogenate activated ST. Gel chromatography on HPLC produced 3-4 protein fractions from the colon cytosol and one of this fraction bearing high molecular weight proteins produced the maximum activation of ST.(ABSTRACT TRUNCATED AT 250 WORDS)