Glycosylated proteins play important roles in a broad spectrum of biochemical and biological processes, and prior reports have suggested that changes in protein glycosylation occur during cancer initiation and progression. Ovarian cancer (OC) is a fatal malignancy, most commonly diagnosed after the development of metastases. Therefore, early detection of OC is key to improving survival. To this end, specific changes of the serum glycome have been proposed as possible biomarkers for different types of cancers. In this study, we extend this concept to OC. To characterize differences in total N-glycan levels, serum samples provided by 20 healthy control women were compared to those acquired from patients diagnosed with late-stage recurrent OC who were enrolled in an experimental treatment trial prior to receiving therapy (N = 19) and one month later, prior to the second treatment cycle (N = 11). Additionally, analyses of the N-glycans associated with IgG and characterization of the relative abundance levels of core vs. outer-arm fucosylation were also performed. The N-linked glycomic profiles revealed increased abundances of tri- and tetra-branched structures with varying degrees of sialylation and fucosylation and an apparent decrease in the levels of “bisecting” glycans in OC samples compared to controls. Increased levels of a-galactosylated structures were observed on N-linked glycans derived from IgG, which were independent of the presence of fucose residues. Elevated levels of outer-arm fucosylation were also identified in the OC samples. These results allowed the control samples to be distinguished from the baseline ovarian cancer patients prior to receiving the experimental treatment. In some cases, the pre-treatment samples could be distinguished from the post-experimental treatment samples, as many of those patients showed a further progression of the disease.

Endotoxins (lipopolysaccharides) are the main components of Gram-negative bacterial outer membranes. A quick and simple way to isolate their lipid region (lipid A) directly from whole bacterial cells was devised. This method using hot ammonium-isobutyrate solvent was applied to small quantities of cells and proved to be indispensable when a rapid characterization of lipid A structure by mass spectrometry was required. Biological activities of endotoxins are directly related to the lipid A structures, which vary greatly with cell growth conditions. This method is suitable for rough-and smooth-type bacteria and very efficient for screening variations in lipid A structures. Data are acquired in a few hours and avoid the use of phenol in extraction. Lipopolysaccharides (LPSs) are the major components of the external membrane of almost all Gram-negative bacteria (1, 2); they are known as endotoxins and may cause several pathophysiological symptoms, such as fever, diarrhea, blood pressure decrease, septic shock, and death (3).The LPS molecular architecture consists of three different regions. The innermost, hydrophobic region, lipid A, is responsible for the major toxic and beneficial properties of bacterial endotoxins (4). Lipid A is the least variable part of the molecule among the different species of a genus, and its structure generally consists of a diglucosamine backbone substituted with varying numbers (usually four to seven) of ester-or amide-linked fatty acids. Phosphate and/or other substituents are linked to carbons at the C-1 and C-4 Ј positions of the glucosamine disaccharide (5). A 2-keto-3-deoxyoctonate (Kdo) unit links the lipid A to a core oligosaccharide (OS) composed of ‫ف‬ 10 sugar residues divided into two regions: a best conserved inner core part and a distal outer core. The core is linked to a third outermost region of a highly immunogenic and variable O-chain polysaccharide (PS) or O-antigen made up of repeating OS units. The latter region of the LPS molecule is responsible for bacterial serological strain specificity (6) and is present only in smooth-type bacteria. The so-called rough-type bacteria produce LPSs lacking O-antigens.Endotoxin can be isolated from Gram-negative bacteria by different methods, the most efficient and commonly used one being the hot phenol-water extraction procedure introduced by Westphal and Lüderitz (7). It was later modified by different authors (8, 9), and specific methods were developed for rough-type endotoxin extractions (10, 11). However, each method requires several days for the extraction and purification of endotoxins and further steps to isolate the lipid A moiety. New methods have been described to extract LPS from small quantities of cells, such as by mini phenol extraction (12) or using an RNAisolating reagent, but these methods still require 2 or 3 days and the use of phenol (13).In early experiments, mineral acid hydrolysis was used to liberate lipid A from endotoxins, splitting the acidolabile ketosidic bond of Kdo. It was followed in 1963 b...

Microcystins (MCYSTs) that accumulated in different organs of the freshwater fish Oreochromis niloticus, collected from a fish farm in Egypt containing heavy blooms of Microcystis aeruginosa, were investigated using an enzyme-linked immunosorbent assay (ELISA). The distribution of MCYSTs in the organs varied significantly. The highest MCYST level was recorded in the guts (821 ng/g fresh weight), followed by the livers (531.8 ng/g) and kidneys (400 ng/g). Smaller amounts of MCYST were detected in muscles (102 ng/g). The present study suggests that fish farms should be monitored for the presence of toxic cyanobacterial blooms to minimize the exposure of fish to potent hepatotoxins.