RBCs stored in CPD-saline-adenine-glucose-mannitol do show a progressive loss of oxygen-dependent metabolic modulation, which is not restored after rejuvenation and which seems partly related to modifications in membrane proteins, mainly band 3.

No abstract

Tobacco smoke is involved in the pathogenesis of several diseases regarding different body systems, mainly cardiovascular and respiratory in addition to its local toxic effect in the oral cavity. The noxious effects of smoke compounds justify the high incidence of periodontal diseases, caries, and neoplastic diseases of oral tissues in smokers. Some toxic components of tobacco smoke, unsaturated and saturated aldehydes, could interact with thiol rich compounds, leading to structural and functional modification of these molecules. Previous papers have demonstrated an in vitro significant decrease of some enzymatic activities, both in plasma and in saliva, following external addition of aldehydes or exposure to cigarette smoke (CS). Furthermore, the same studies underlined the protective effect exerted by the addition of glutathione (GSH) against the damaging role of smoke aldehydes. In this study some salivary enzymes (lactic dehydrogenase [LDH], aspartate aminotransferase [AST] and amylase), and total GSH were measured in 20 volunteers smokers, before and just after smoking a single cigarette. All enzymatic activities showed a significant inhibition following a single cigarette, probably due to the interaction between smoke aldehydes and–SH groups of the enzyme molecules. Moreover, the percentage of the enzymatic inhibition showed a negative correlation with the basal level of salivary GSH. Our results emphasize that not only one cigarette is sufficient to impair the salivary enzymatic activities but also strengthen the proposed protective role of GSH against the noxious biochemical effects of CS.

BACKGROUND The authors evaluated serum levels of folate, homocysteine, and vitamin B12 in patients with head and neck squamous cell carcinoma (HNSCC) and in patients with laryngeal leukoplakia, a well known preneoplastic lesion. METHODS One hundred forty‐four consecutive, untreated patients with HNSCC and 40 consecutive, untreated patients with laryngeal leukoplakia were enrolled in the Department of Otolaryngology at the authors' institution. Data from those patients were compared with data from one control group, which included 90 smokers, and from another control group, which included 120 nonsmokers. Serum levels of homocysteine, folate, and vitamin B12 were measured by an automated immunoassay method based on fluorescence polarization immunoassay technology. RESULTS Comparing groups by Student–Newman–Keuls test, serum folate levels were significantly lower in patients with HNSCC and in patients with laryngeal leukoplakia compared with serum folate levels in both the smoker control group and the nonsmoker control group. Serum homocysteine levels in patients with HNSCC were significantly higher compared with homocysteine levels both in the smoker and nonsmoker control groups and in patients with laryngeal leukoplakia. There were no statistically significant differences between groups in serum vitamin B12 levels. CONCLUSIONS A role for folate deficiency as a risk factor in head and neck carcinogenesis is plausible. A chemoprevention protocol with folate is both feasible and ethically correct and is in progress at the authors' institution. Homocysteine levels in patients with HNSCC probably are affected largely by the HNSCC phenotype. An accumulation of homocysteine may reveal a genetic defect, which, theoretically, may be a target for pharmacologic therapy, for example, with antifolic drugs. Cancer 2005. © 2004 American Cancer Society.

Background/Objectives: To compare the efficacy of a diet rich in natural folate and of two different folic acid supplementation protocols in subjects with “moderate” hyperhomocysteinemia, also taking into account C677T polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. Subjects/Methods: We performed a 13 week open, randomized, double blind clinical trial on 149 free living persons with mild hyperhomocyteinemia, with daily 200 μg from a natural folate-rich diet, 200 μg [6S]5-methyltetrahydrofolate (5-MTHF), 200 μg folic acid or placebo. Participants were stratified according to their MTHFR genotype. Results: Homocysteine (Hcy) levels were reduced after folate enriched diet, 5-MTHF or folic acid supplementation respectively by 20.1% (p < 0.002), 19.4% (p < 0.001) and 21.9% (p < 0.001), as compared to baseline levels and significantly as compared to placebo (p < 0.001, p < 0.002 and p < 0.001, respectively for enriched diet, 5-MTHF and folic acid). After this enriched diet and the folic acid supplementation, Hcy in both genotype groups decreased approximately to the same level, with higher percentage decreases observed for the TT group because of their higher pre-treatment value. Similar results were not seen by genotype for 5-MTHF. A significant increase in RBC folate concentration was observed after folic acid and natural folate-rich food supplementations, as compared to placebo. Conclusions: Supplementation with natural folate-rich foods, folic acid and 5-MTHF reached a similar reduction in Hcy concentrations.

Salivary glutathione levels may be an index of oxidative stress at the level of the upper airways and in particular of oral cavity and pharynx. Therefore, high salivary glutathione may be an epidemiological marker to identify subjects with an increased risk of developing HNSCC, to submit to strict follow-up and chemoprevention. Metabolic alterations of saliva could be both an epidemiological marker and a target for chemoprevention of oral and oropharyngeal carcinogenesis.

IBD patients have a higher prevalence of hyperhomocysteinemia than do healthy controls. Folate deficiency is the only independent risk factor in developing hyperhomocysteinemia.

We have studied the relationship between diabetes‐associated autoantibodies and various HLA genotypes and alleles in patients with newly diagnosed type 1 diabetes, in non‐diabetic siblings and in children representing the general population to test the hypothesis that specific HLA genes regulate the humoral immune response to various autoantigens. Among the newly diagnosed patients we observed that those carrying the DR4‐DQB1*0302 haplotype had increased levels of insulin autoantibodies (IAA) and IA‐2 antibodies (IA‐2A), but low levels of GAD antibodies (GADA). In contrast, those with the DR3‐DQB1*02 haplotype had increased GADA titers but low IAA and IA‐2 levels. DQB1*02‐homozygous patients had a conspicuously low frequency and low levels of IA‐2A. Among the siblings there was an apparent association between genetic risk and the prevalence of islet cell antibodies (ICA), IAA, GADA, IA‐2A and multiple autoantibodies, the latter being detectable at a frequency of 24.1% in high risk siblings and at a frequency of only 0.9% in those with genotypes conferring disease protection. Among 7–16‐year‐old Finnish schoolchildren there was an association between GADA and the DQB1*02/*0302 genotype and the DQB1*0302 allele. Among young children identified from the general population based on high (DQB1*02/0302 heterozygosity) or moderate (DQB1*0302/x; x ≠ *02, *0301, *0602, *0603) genetic risk for type 1 diabetes the high risk children seroconverted more often to positivity for ICA, GADA and IA‐2A over their first 2 years of life. Among older sibs of these children we observed an obvious relationship between the degree of genetic risk and the frequency of ICA, IAA, GADA, IA‐2A, and multiple antibodies. Taken together these observations suggest that HLA genes have a strong impact on the appearance of diabetes‐associated autoantibodies both in first‐degree relatives of affected children and in the general population. In patients with newly diagnosed disease IA‐2A may be a more specific marker of beta‐cell damage, whereas GADA might reflect a propensity to autoimmunity in general. © 2002 Wiley‐Liss, Inc.