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Gonadotrophin surge attenuating factor (GnSAF) is a new non-steroidal ovarian substance, different from inhibin, which attenuates the pre-ovulatory luteinizing hormone (LH) surge in superovulated women. Human follicular fluid (FF) was used as a source for the isolation of GnSAF, the activity of which was monitored in an in-vitro pituitary bioassay. Primary rat pituitary cells were incubated with test substances for 48h and subsequently washed and incubated with 0.1μmol/l gonadotrophin releasing hormone (GnRH) plus test substances for 4 h. GnSAF activity was expressed as the reduction of GnRH-induced LH secretion in the 4 h incubation. GnSAF was purified from 250 ml of FF which was heat-treated at 80°C for 5 min. Heparin-sepharose chromatography, Con-A sepharose chromatography, reversed-phase high-performance liquid chromatography (HPLC) and preparative native gel electrophoresis were used for GnSAF fractionation. Using these purification steps, we have obtained an apparently homogeneous preparation that stains as a single band on sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis. GnSAF has an apparent molecular weight of 12.5 kDa and was identified by amino acid sequence (mass spectrometry) to be the C-terminal fragment of human serum albumin. [ABSTRACT FROM PUBLISHER]

Aim: To investigate aberrant DNA methylation of CpG islands and subsequent low- or high-level DNA microsatellite instability (MSI) which is assumed to drive colon carcinogenesis., Methods: DNA of healthy individuals, adenoma (tubular or villous/tubulovillous) patients, and colorectal carcinoma patients who underwent colonoscopy was used for assessing the prevalence of aberrant DNA methylation of human DNA mismatch repair gene mutator L homologue 1 (hMLH1), Cyclin-dependent kinase inhibitor 2A (CDKN2A/p16), and O-6-methylguanine DNA methyltransferase (MGMT), as well as their relation to MSI., Results: The frequency of promoter methylation for each locus increased in the sequence healthy tissue/adenoma/carcinoma. MGMT showed the highest frequency in each group. MGMT and CDKN2A/p16 presented a statistically significant increase in promoter methylation between the less and more tumorigenic forms of colorectal adenomas (tubular vs tubullovillous and villous adenomas). All patients with tubulovillous/villous adenomas, as well as all colorectal cancer patients, showed promoter methylation in at least one of the examined loci. These findings suggest a potentially crucial role for methylation in the polyp/adenoma to cancer progression in colorectal carcinogenesis. MSI and methylation seem to be interdependent, as simultaneous hMLH1, CDKN2A/p16, and MGMT promoter methylation was present in 8/9 colorectal cancer patients showing the MSI phenotype., Conclusion: Methylation analysis of hMLH1, CDKN2A/p16, and MGMT revealed specific methylation profiles for tubular adenomas, tubulovillous/villous adenomas, and colorectal cancers, supporting the use of these alterations in assessment of colorectal tumorigenesis.

Introduction: Alterations in the lipid composition and overall structure of plasma lipoproteins have been correlated with pathological situations such as dyslipidaemia, coronary heart disease (CHD), hypertension, and renal disease. In the present study 1H NMR spectroscopy was used to analyse the lipid composition of HDL and nonHDL lipoproteins in patients with triple vessel CHD and in patients with normal coronary arteries., Methods: Serum samples were collected from 50 patients with triple vessel CHD and 41 patients with normal coronary vessels, both documented angiographically. The classical risk factors for CHD were recorded and each patient's standard lipid profile was determined. HDL and nonHDL lipoprotein particles were separated by precipitation with Dextran Sulphate/MgCl2. HDL and nonHDL lipid fractions were extracted with chloroform:methanol (1:2, v/v). 1H NMR spectra were recorded on a Bruker DRX-600 spectrometer., Results: In the HDL fraction of patients with triple vessel disease the percentage of triglycerides was significantly higher than in those with normal coronary arteries, whereas the percentages of cholesterol esters, phosphatidylcholine and sphingomyelin, as well as polyunsaturated fatty acids, such as linoleic, arachidonic, and eicosapentaenoic, were significantly lower. In the nonHDL fraction significantly higher levels of triglycerides and lower levels of polyunsaturated fatty acids were observed., Conclusions: Patients with established CHD show significant alterations in the composition of plasma lipoproteins compared to those with normal coronary arteries. Further study of plasma lipoprotein composition might be able to identify components as indexes for the existence of CHD.