Food Intake and Serum Selenium Concentration in Elderly People

BACKGROUND/AIMS

It is becoming apparent that the essential trace element selenium plays a critical role in the maintenance of optimal health status. The objective of this study was to identify the food groups that most contributed to selenium intake and its serum levels in elderly people.

METHODS

Dietary intake was assessed in 205 institutionalized elderly by means of a 1-year food frequency questionnaire (FFQ). Intake of macronutrients and minerals of the diet were estimated. Selenium was determined in serum and analyzed by graphite-furnace atomic absorption spectrometry.

RESULTS

Selenium intake and serum concentration were both within the normal range. The major contributors to selenium intake were cereals and bakery, fish and shellfish, meat and meat products and dairy products. All of them except cereals were also associated to serum selenium. Intake of animal protein, but not the vegetable one, contributed to serum selenium.

CONCLUSION

An adequate intake of fish and meat would be of importance to improve selenium status and health principally in elderly people who are at high risk of mineral deficiency.

Folate and cobalamin synergistically decrease the risk of high plasma homocysteine in a nonsupplemented elderly institutionalized population

OBJECTIVE

Total plasma homocysteine (tHcy) has been associated with an increased risk of cardiovascular disease in the general population and elderly subjects are at high risk of elevated homocysteine because of an impaired vitamin status. The aim of the present study was to determine the independent and interactive association of adequate folate and cobalamin (intake and serum levels) with tHcy in elderly subjects who were not taking vitamin supplementation.

DESIGN AND METHODS

Cross-sectional analysis of a sample of 140 elderly recruited from seven nursing homes in Asturias (Northern Spain). Dietary intake was assessed by a food frequency questionnaire, and serum folate, cobalamin, and tHcy were determined in fasting blood samples.

RESULTS

Mean tHcy concentration was 13.3 micromol/L (upper quartile of tHcy >16.0 micromol/L) and was inversely correlated with serum folate. Subjects with an adequate intake or serum levels of both folate and B12 were at a reduced risk of being in the highest quartile of tHcy. In both cases, the reduction of high tHcy (upper quartile) risk was found to be greater than expected when subjects with high levels of both vitamins were considered together.

CONCLUSIONS

Adequate folate and cobalamin (both intake and serum levels) act synergistically to decrease the risk of high total plasma homocysteine levels in this elderly population.

Serum selenium is associated with plasma homocysteine concentrations in elderly humans

Low selenium levels in humans have been associated with several pathologies; however, an earlier animal investigation found a direct association between Se intake and total plasma homocysteine (tHcy) concentrations. To date, the importance of serum selenium levels in association with tHcy in humans has not been determined. We evaluated the cross-sectional association of blood selenium concentrations with plasma tHcy and other determinants of this cardiovascular disease risk factor. We estimated protein intake and measured the blood status of selenium, tHcy, and several other related factors in serum such as folate, vitamin B-12, and creatinine. Serum selenium was inversely associated with tHcy, explaining 5.8% of tHcy variance with respect to 2.2% accounted for by serum folate. Furthermore, there was a 63% decreased risk of higher tHcy concentrations (>14 micro mol/L) for subjects with serum selenium in the highest tertile (P = 0.013). We also found an inverse association of protein intake with tHcy in men (beta = -0.144; P = 0.036), which disappeared after controlling for serum Se concentrations (beta = -0.055; P = 0.003). In conclusion, selenium should be considered as a potential factor to lower tHcy. In addition, the described association between protein intake and homocysteine levels could be mediated by this trace element.

Diet score is associated with plasma homocysteine in a healthy institutionalised elderly population

BACKGROUND AND AIM

Total plasma homocysteine (tHcy) is an independent risk factor for cardiovascular diseases. Among other dietary and non-dietary factors, B vitamins, such as folate, riboflavin and cobalamin, are primary determinants of tHcy in the general population. However, research has concentrated on the relationship of these nutrients with tHcy, and little is known about overall eating patterns and tHcy.

METHODS AND RESULTS

In this study, we analysed whether a diet score based on the consumption of folate-, riboflavin- and cobalamin-rich food groups was associated with tHcy in a sample of 140 institutionalised elderly subjects (59 men and 81 women aged 60-80 years) from Northern Spain. The food groups identified as the major contributors to the intake of the three vitamins were vegetables, fruit, fish, meat and milk and dairy products. The mean tHcy level was 13.3+/-5.1 micromol/L (range: 3.9-30.7 micromol/L). None of the food groups predicted tHcy levels individually, but the overall diet score was inversely associated with tHcy in a multiple linear regression analysis. High tHcy levels (>16 micromol/L) were almost twice as prevalent in the groups scoring less than 7 than in those scoring 7 or more (37.5 vs 19.6%, p=0.021).

CONCLUSIONS

These data suggest that a dietary pattern characterised by high intakes of B vitamin-rich foods is associated with a lower tHcy concentration and a reduced percentage of high tHcy levels in elderly subjects. They also support the use of dietary pattern approaches to evaluate the relationships between diet and health outcomes that go beyond single nutrient analyses.

Plasma iron is associated with lipid peroxidation in an elderly population

Epidemiological evidence has raised concern that a moderate elevation in body iron stores may increase oxidative stress and risk of heart disease. We examined the cross-sectional association between plasma iron and factors that could affect its levels (antioxidant enzymes, diet), with the concentration of plasma malondialdehyde (MDA) as a marker of lipid peroxidation. Participants were 162 non-smoking institutionalised elderly. Our results show that those in the highest tertile of plasma iron were at least twice as likely to have higher plasma MDA levels. Among the factors affecting plasma iron levels, we found that the upper tertile of erythrocyte-superoxide dismutase (E-SOD) was inversely associated with higher plasma iron, and potato intake explained a sizeable proportion of the variation in plasma iron levels. In addition to potatoes, eggs, wine, fruit in men and green vegetables in women showed a positive association with plasma iron levels. Only potatoes in both sexes, wine in men and eggs in women had an independent effect on plasma MDA. Potatoes, wine, plasma lycopene and plasma iron accounted for 43% of the variability in plasma MDA for males, and E-SOD, potatoes, eggs, plasma lycopene and plasma iron explained 45% for women. A longitudinal study should confirm, whether these MDA levels are related to morbidity and mortality.

Synthesis and biological evaluation of 3,4-diaryloxazolones: A new class of orally active cyclooxygenase-2 inhibitors

A series of 3,4-diaryloxazolones were prepared and evaluated for their ability to inhibit cyclooxygenase-2 (COX-2). Extensive structure-activity relationship work was carried out within this series, and a number of potent and selective COX-2 inhibitors were identified. The replacement of the methyl sulfone group on the 4-phenyl ring by a sulfonamide moiety resulted in compounds with superior in vivo antiinflammatory properties. In the sulfonamide series, the introduction of a methyl group at the 5-position of the oxazolone ring gave rise to very COX-2-selective compounds but with decreased in vivo activity. Selected 3,4-diaryloxazolones exhibited excellent activities in experimental models of arthritis and hyperalgesia. The in vivo activity of these compounds was confirmed with the evaluation of their antipyretic effectiveness and their ability to inhibit migration of proinflammatory cells. As expected from their COX-2 selectivity, most of the active compounds lacked gastrointestinal toxicity in vivo in rats after a 4-day treatment of 100 mg/kg/day. Within this novel series, sulfonamides 9-11 have been selected for further preclinical evaluation.

Inhibition of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) secretion but not IL-6 from activated human peripheral blood monocytes by a new synthetic demethylpodophyllotoxin derivative

A newly synthesized demethylpodophyllotoxin derivative, 4-O-butanoyl-4'-demethylpodophyllotoxin (BDPT) or BN58705, has recently been shown to exert a potent cytotoxic activity in vitro against a variety of drug-resistant human tumor cell lines. The effect of this agent on effector cells of the immune system, however, has not been examined. The present study investigated the effect of BDPT on the response of activated human peripheral blood derived monocytes (PBM) to secrete cytokines. Activation of PBM overnight with LPS, IFN-gamma, or PMA resulted in secretion into the supernatant of TNF-alpha, IL-1 beta, IL-6, and IL-8 as assessed by ELISA. The addition of BDPT to the stimulated cultures resulted in significant inhibition of TNF-alpha and IL-1 beta secretion, whereas the secretion of IL-6 and IL-8 was not affected. The selective inhibition of TNF-alpha and IL-1 beta secretion by BDPT-treated PBM was observed with all three stimuli tested. The inhibitory effect mediated by BDPT was concentration dependent and was optimal at 6-20 microM. Time kinetic analysis indicated that the inhibition of secretion was rapid and detected as soon as 2 hr following stimulation of the PBM and lasted for as long as 24 hr. A comparison was made between BDPT and pentoxyfilline, a xanthine-derived phosphodisterase inhibitor that was reported to inhibit TNF-alpha and IL-1 beta secretion by PBM. Both BDPT and PTX showed similar time kinetics and patterns of inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro inhibition of marginal caries-like lesions with fluoride-containing amalgam

Carious lesions surrounding restorations represent one of the main causes of restoration failure. The addition of fluoride compounds to dental restorative materials prevents or reduces recurrent caries. The purpose of this study was to compare the capacity of three restorative materials to inhibit the development of recurrent caries in vitro. Thirty unrestored, noncarious premolars that were being extracted for orthodontic reasons were sectioned in half buccolingually and divided into three groups. One of the groups was restored with conventional amalgam. The second group was restored with a fluoride-containing amalgam, and the third group was restored with a glass-ionomer cement. All the samples were submitted to a medium containing Streptococcus mutans (Ingbritt strain) for 8 weeks. At the end of the 8-week incubation period, the samples were cut into 100 microns sections, soaked in Quinoline (IR = 1.62), and observed with light transmission and polarized light microscopy. The development of artificial caries in the cavity walls was measured in microns. The results show that conventional amalgam had an average caries penetration of 160 microns, fluoride-containing amalgam 46 microns, and glass-ionomer cement 11 microns. Glass-ionomer cement gave the best protection against recurrent caries.

Maturation of human myelomonocytic leukemia cells following ligation of the low affinity receptor for IgE (Fc epsilon RII/CD23)

The regulation of the low affinity receptor for IgE (Fc epsilon RII/CD23) expression and its role were investigated in U937 cell line and in leukemic cells from a patient (Amb) with acute myeloblastic leukemia. Both cell populations were CD23- but could acquire CD23 expression following treatment with IL-4. CD23+ cells, however, remained blastic and did not show any significant phenotypical and functional modifications. Following ligation of the CD23 on U937 and Amb cells by anti-CD23 mAb, these leukemic cells differentiated into mature monocyte/macrophage-like cells. CD23 ligation promoted the expression of the monocyte marker, CD14, increased the expression of the common beta chain of the LFA-1 family (CD18), and down-regulated the expression of the promonocytic marker CD33. Morphological and phenotypical changes were associated with functional modifications as CD23 ligation allowed the acquisition of the oxidative metabolism in leukemic cells as revealed by luminol-dependent chemiluminescence. As in mature monocytes, CD23 ligation induced an accumulation of intracellular cAMP in leukemic cells. These data indicate that ligation of CD23 may induce the maturation of myelomonocytic cells into monocytic-like cells.

Role of platelet-activating factor in the ovine heparin-protamine reaction

Platelet-activating factor (PAF) infusion into sheep, as well as protamine reversal of heparin anticoagulation, causes thromboxane release into plasma, pulmonary hypertension, hypoxemia, and leukopenia. We investigated the possible role of PAF in the heparin-protamine reaction. Intravenous protamine was administered to neutralize heparin anticoagulation in five awake sheep and caused an increase of mean pulmonary arterial pressure from 16.6 +/- 1 (SE) mmHg at base-line to 47 +/- 9 mmHg at 1 min after protamine injection (P < 0.01) because of a 4.5-fold increase of pulmonary vascular resistance. This neutralization reaction induced a 25% reduction of circulating leukocyte count and arterial PO2. Undetectable blood levels of PAF were measured by bioassay and high-performance liquid chromatography during these heparin-protamine reactions. Infusion of BN 52021 (20 mg/kg), a PAF receptor antagonist, before rechallenging the same sheep with heparin and then protamine did not reduce the level of peak pulmonary hypertension or the degree of hypoxemia and leukopenia. We conclude that the leukopenia and thromboxane-mediated pulmonary vasoconstriction occurring after rapid intravascular formation of heparin-protamine complexes in sheep are not due to the release of PAF.

Defective IFN-gamma production in the human neonate. II. Role of increased sensitivity to the suppressive effects of prostaglandin E

Analysis of endogenous production and effects of exogenous addition of interleukin 2 (IL 2), leukotrienes (LT), and prostaglandin E (PGE) has been used to investigate the dysregulation responsible for impaired PHA-induced IFN-gamma secretion by cord blood leukocytes (CBL). The addition of LT or IL 2 could not reverse the IFN defect of CBL. The production of these two mediators was found to be normal in CBL cultures. CBL and control leukocytes from adult donors produced comparable amounts of PGE2. In contrast, sensitivity to the suppressive effects of PGE2 on IFN-gamma secretion was much higher with CBL than with control leukocytes. Treatment with indomethacin reversed the IFN-gamma defect with most CBL tested, and the addition of physiologic amounts of PGE2 to indomethacin-treated cultures resulted in a profound impairment of IFN-gamma production similar to that of untreated CBL cultures. Preincubation of CBL for 24 hr before PHA stimulation resulted in restoration of a normal sensitivity to exogenous PGE2, in parallel with correction of the IFN-gamma defect. Our observations suggest that the impairment of IFN-gamma secretion in neonates is not due to deficient amplification circuits, but is the consequence of an exaggerated cellular sensitivity to the suppressive effects of PGE produced endogenously in normal amounts.

Defective IFN-gamma production in the human neonate. II. Role of increased sensitivity to the suppressive effects of prostaglandin E

Analysis of endogenous production and effects of exogenous addition of interleukin 2 (IL 2), leukotrienes (LT), and prostaglandin E (PGE) has been used to investigate the dysregulation responsible for impaired PHA-induced IFN-gamma secretion by cord blood leukocytes (CBL). The addition of LT or IL 2 could not reverse the IFN defect of CBL. The production of these two mediators was found to be normal in CBL cultures. CBL and control leukocytes from adult donors produced comparable amounts of PGE2. In contrast, sensitivity to the suppressive effects of PGE2 on IFN-gamma secretion was much higher with CBL than with control leukocytes. Treatment with indomethacin reversed the IFN-gamma defect with most CBL tested, and the addition of physiologic amounts of PGE2 to indomethacin-treated cultures resulted in a profound impairment of IFN-gamma production similar to that of untreated CBL cultures. Preincubation of CBL for 24 hr before PHA stimulation resulted in restoration of a normal sensitivity to exogenous PGE2, in parallel with correction of the IFN-gamma defect. Our observations suggest that the impairment of IFN-gamma secretion in neonates is not due to deficient amplification circuits, but is the consequence of an exaggerated cellular sensitivity to the suppressive effects of PGE produced endogenously in normal amounts.