Persistently raised C-reactive protein levels are associated with advanced periodontal disease

Objective: The aim was to investigate whether there was an association between periodontitis or tooth loss in a homogeneous group of 60-70-year-old Western European men and either a sustained high or low level of C-reactive protein (CRP).
Material and Methods: Men enrolled in a cohort study of cardiovascular disease in Northern Ireland were screened in 1990-1994 and rescreened in 2001-2004, when a periodontal examination was completed. High-sensitivity CRP was measured from fasting blood samples. There were 806 men with six or more teeth who had either a high level (>3 mg/l) or a lower level of CRP at both time points. Multivariate analysis was carried out using logistic regression with adjustment for possible confounders. Models were constructed with the CRP level as the outcome variable and various measures of periodontal status (low and high threshold periodontitis) or tooth loss as predictor variables. Confounders included in the analysis were known cardiovascular risk factors of age, smoking, diabetes, BMI and socioeconomic status.
Results: There were 67 men who had a high value of CRP (>3 mg/l) and 739 men who had a CRP value =3 mg/l at both time points. The unadjusted odds ratio (OR) for advanced periodontitis to be associated with high CRP was 3.62, p=0.0003. The association was somewhat attenuated but remained significant (OR=2.49, p=0.02) after adjustment for confounders. A high level of tooth loss was also associated with high CRP with an adjusted OR of 2.17, p=0.008. Low threshold periodontitis was not associated with the level of CRP.
Conclusion: There was an association between advanced periodontitis and elevated CRP levels as measured at two time points at a 10-year interval in the 60-70-year-old European males investigated. This association was adjusted for various cardiovascular risk factors. There was also an association between high levels of tooth loss and high CRP in the men studied.

Stress resistance and disease resistance in seaweeds: The role of reactive oxygen metabolism

It has become clear over the last 15-20 years that the immediate effect of a wide range of environmental stresses, and of infection, on vascular plants is to increase the formation of reactive oxygen species (ROS) and to impose oxidative stress on the cells. Since 1994, sufficient examples of similar responses in a broad range of marine macroalgae have been described to show that reactive oxygen metabolism also underlies the mechanisms by which seaweeds respond (and become resistant) to stress and infection. Desiccation, freezing, low temperatures, high light, ultraviolet radiation, and heavy metals all tend to result in a gradual and continued buildup of ROS because photosynthesis is inhibited and excess energy results in the formation of singlet oxygen. The response to other stresses (infection or oligosaccharides which signal that infection is occurring, mechanical stress, hyperosmotic shock) is quite different-a more rapid and intense, but short-lived production of ROS, described as an

Characterization of a ligand-attenuated binding site on glycoprotein IIb/IIIa

We describe an epitope on the platelet integrin, GPIIb/IIIa, identified by the monoclonal antibody, 4F8, which is attenuated by small-molecule GPIIb/IIIa ligands. 4F8 did not bind to the ligand binding pocket as it did not compete with a radiolabelled antagonist, H-3-SC-52012. This indicates that the 4F8 epitope behaves as a ligand-attenuated binding site (LABS). Ligand-induced attenuation of 4178 was an active process as it was prevented by pretreating platelets with cytochalasin D and reduced by prostaglandin E-1 or inhibition of protein kinase C. Disappearance of the epitope was required for full platelet activation as 4F8 prevented platelet aggregation without inhibiting fibrinogen binding. These results suggest a model where disappearance of the 4F8 epitope is a secondary event required for full

Formation of methionine sulfoxide during glycoxidation and lipoxidation of ribonuclease A

Chemical modification of proteins by reactive oxygen species affects protein structure, function and turnover during aging and chronic disease. Some of this damage is direct, for example by oxidation of amino acids in protein by peroxide or other reactive oxygen species, but autoxidation of ambient carbohydrates and lipids amplifies both the oxidative and chemical damage to protein and leads to formation of advanced glycoxidation and lipoxidation end-products (AGE/ALEs). In previous work, we have observed the oxidation of methionine during glycoxidation and lipoxidation reactions, and in the present work we set out to determine if methionine sulfoxide (MetSO) in protein was a more sensitive indicator of glycoxidative and lipoxidative damage than AGE/ALEs. We also investigated the sites of methionine oxidation in a model protein, ribonuclease A (RNase), in order to determine whether analysis of the site specificity of methionine oxidation in proteins could be used to indicate the source of the oxidative damage, i.e. carbohydrate or lipid. We describe here the development of an LC/MS/MS for quantification of methionine oxidation at specific sites in RNase during glycoxidation or lipoxidation by glucose or arachidonate, respectively. Glycoxidized and lipoxidized RNase were analyzed by tryptic digestion, followed by reversed phase HPLC and mass spectrometric analysis to quantify methionine and methionine sulfoxide containing peptides. We observed that: (1) compared to AGE/ALEs, methionine sulfoxide was a more sensitive biomarker of glycoxidative or lipoxidative damage to proteins; (2) regardless of oxidizable substrate, the relative rate of oxidation of methionine residues in RNase was Met(29) > Met(30) > Met(13), with Met(79) being resistant to oxidation; and (3) arachidonate produced a significantly greater yield of MetSO, compared to glucose. The methods developed here should be useful for assessing a protein's overall exposure to oxidative stress from a variety of sources in vivo. (c) 2006 Elsevier Inc. All rights reserved.

Site specificity of glycation and carboxymethylation of bovine serum albumin by fructose

We report an investigation of the site specificity, extent and nature of modification of bovine serum albumin (BSA) incubated with fructose or glucose at physiological temperature and pH. Sites of early glycation (Heyns rearrangement products (HRP) from fructose; fructoselysine (FL) from glucose) as well as advanced glycation (N-epsilon-(carboxymethyl)lysine; CML) wereanalyzed by liquid chromatography-mass spectrometry. The major site of modification by fructose, like glucose, is Lysine-524 and this results in, respectively, 31 and 76% loss of the corresponding unmodified tryptic peptide, Gln525-Lys533. In addition, total lysine, HRP, FL, CML and N-epsilon-(carboxyethyl)lysine in the incubations, was quantified. Almost all of the loss of lysine in the fructose-modified BSA was attributed to the formation of CML, with the yield of CML being up to 17-fold higher than glucose-modified BSA. A mechanism for the formation of CML from the HRP is proposed.

Activation of waste MDF sawdust charcoal and its reactive dye adsorption characteristics

This paper reports an experimental investigation of converting waste medium density fibreboard (MDF) sawdust into chars and activated carbon using chemical activation and thermal carbonisation processes. The MDF sawdust generated during the production of architectural mouldings was characterised and found to have unique properties in terms of fine particle size and high particle density. It also has a high content of urea formaldehyde resin used as a binder in the manufacturing of MDF board. Direct thermal carbonisation and chemical activation of the sawdust by metal impregnation and acid (phosphoric acid) treatment prior to pyrolysis treatment were carried out. The surface morphology of the raw dust, its chars and activated carbon were examined using scanning electron microscopy (SEM). Adsorptive properties and total pore volume of the materials were also analysed using the BET nitrogen adsorption method. Liquid adsorption of a reactive dye (Levafix Brilliant red E-4BA) by the derived sawdust carbon was investigated in batch isothermal adsorption process and the results compared to adsorption on to a commercial activated carbon (Filtrasorb F400). The MDF sawdust carbon exhibited in general a very low adsorption capacity towards the reactive dye, and physical characterisation of the carbon revealed that the conventional chemical activation and thermal carbonisation process were ineffective in developing a microporous structure in the dust particles. The small size of the powdery dust, the high particle density, and the presence of the urea formaldehyde resin all contributed to the difficulty of developing a proper porous structure during the thermal and chemical activation process. Finally, activation of the dust material in a consolidated form (cylindrical pellet) only achieved very limited improvement in the dye adsorption capacity. This original study, reporting some unexpected outcomes, may serve as a stepping-stone for future investigations of recycle and reuse of the waste MDF sawdust which is becoming an increasing environmental and cost liability. (C) 2004 Elsevier Ltd. All rights reserved.