Utility technology in the assessment of the cut-off between a negative and a positive test in a caries prediction model.

The methodology for the assessment of a negative or positive test in caries prediction models has not received much attention. This study aims to explain how utility technology could be applied in a caries prediction model for the assessment of the cut-off between a negative and a positive test. In this study loss of utilities was assigned to false outcomes of the prediction test. A regression equation with past caries experience variables of 11-year-old children and caries increment in the 11- to 15-year forecast period as outcome was computed. The adjusted explained variance for caries increment was 0.45. Formulas were constructed for the loss of utilities for false-negative tests whereas false-positive tests were corrected with a fixed loss of utilities. Each 11-year-old child of the 252 children was screened at various points of the regression equation. Loss of utilities was calculated for each child on the basis of the validation criterion, the outcome of the test and the actual caries increment of the child. The point on the regression equation with the least loss of utilities for the whole group was taken as the cut-off between a negative and a positive test. If the validation criterion for the prediction period was set on no caries, the prediction model resulted in a sensitivity of 84% and a specificity of 73%. This prediction model has potential when caries incidence is low and resources limited.

Systemic inflammatory markers in older persons: the effect of oral nutritional supplementation with prebiotics.

OBJECTIVE: To evaluate the effect of oral nutritional supplementation with and without oligosaccharides on gut bacteriology, in particular the bifidogenic flora, and on immunology and inflammatory parameters in older persons at risk of malnutrition. DESIGN: Prospective, randomized, double-blind, controlled study. SETTING: Division of Geriatric Medicine, St. Louis University, Missouri, United States. PARTICIPANTS: Seventy-four community dwelling elderly and/or nursing home subjects (age superior 70 y; 84 +/- 7 years) either undernourished or at risk of undernutrition. INTERVENTION: Daily liquid supplements, with (1.3 g/250 ml) and without oligosaccharides (OS) for 12 weeks. MEASUREMENTS: Nutritional evaluation, serum immunoglobulins, lymphocyte subsets, various cytokines and the endotoxin soluble receptor CD14 (sCD14) in serum, and cytokines specific mRNA in peripheral blood mononuclear cells at baseline and 12 weeks, and fecal bacteriologicy. RESULTS: Specific mRNA extracted from blood leucocytes showed a different level of pro-inflammatory gene activation: TNF-alpha mRNA and IL-6 mRNA diminished in the OS group after 12 weeks, while no changes were detected in the control group (P=0.05 and P=0.04 respectively). Serum levels of sCD14, a product shed by activated macrophages, decreased only in the OS group without reaching statistical significance (P=0.08). No significant differences were detected in the fecal gut flora or in the nutritional parameters. CONCLUSIONS: This study shows that the administration of supplements in older persons at risk of malnutrition may benefit from the addition of prebiotics that can improve the low noise inflammatory process frequently observed in this population.

Effectiveness of ART and traditional amalgam approach in restoring single-surface cavities in posterior teeth of permanent dentitions in school children after 6.3 years.

OBJECTIVES: The Atraumatic Restorative Treatment (ART) approach was compared with the traditional amalgam (TA) approach in order to test their appropriateness to complement a preventive and educational school oral health programme in Syria. METHODS: Using a parallel group design, 370 and 311 grade 2 children were randomly assigned to the ART and the TA group respectively. Eight dentists placed 1117 single- and multiple-surface restorations. A modified actuarial method was used to estimate survival curves. The jackknife method was applied to calculate the standard error in the cumulative survival percentages. RESULTS: A statistically significant difference in cumulative survival percentages between single-surface non-occlusal ART and comparable amalgam restorations was observed after 4.3, 5.3 and 6.3 years. The survival of single-surface non-occlusal ART posterior restorations (80.2 +/- 4.9%) was statistically significantly higher than that of occlusal posterior ART restorations (64.8 +/- 3.9%) at evaluation year 6.3. There was no statistically significant difference observed between survival percentages of large (55.8 +/- 10%) and that of small (69.2 +/- 4.6%) single-surface posterior ART restorations after 6.3 years. There was an operator effect observed for single-surface ART and comparable amalgam restorations. Secondary caries was observed in 2.3% of single-surface ART restorations and in 3.7% of single-surface amalgam restorations during the 6.3 year observation period. CONCLUSIONS: The ART approach provided higher survival percentages for single-surface restorations than the TA approach over 6.3 years and is therefore appropriate for use in school oral health programmes. Secondary caries was only a minor reason for ART restorations to fail. An operator effect was observed for both treatment approaches.

Oral health service systems in Gauteng Province, South Africa.

OBJECTIVES: To describe the provision of restorative care and dental operators' opinion about their conditions of service in a South African provincial oral health service system. DESIGN: Assessment of oral health service over a four-month period. SETTING: Gauteng Province, South Africa. SUBJECTS: Dental operators in public oral health service. INTERVENTIONS: Operator interview, collection of treatment statistics, calculation of the mean score of restoration-extraction ratio per operator. MAIN OUTCOME MEASURES: Number and type of restorations and tooth extractions rendered, daily patient load, perceived occupational stress level and opinion about main reasons for operator stress. RESULTS: A total of 88,705 patients had been treated. The mean number of patients treated daily was 26 (SD = 8.4). Operators extracted 39,242 teeth and placed 2992 restorations. The main type of dental treatment was extraction. The mean score of the restoration-extraction ratio per operator was 0.09 in the primary, and 0.07 in the permanent dentition. The mean level of stress was 4.9 (SD = 1.9). The majority of operators regarded patients' high dental anxiety as the main reason for stress, followed by high patient load. The mean level of stress increased with the increase in number of patients treated per day (r = 0.44, p = 0.004) and also with the increase in the number of tooth extractions performed per day (r = 0.41, p = 0.008). CONCLUSIONS: Restorative dental care in this public oral health service is limited, tooth extraction being the predominant treatment provided. High patient load and high patient levels of dental anxiety determine this situation, according to the operators. The health authority should introduce appropriate solutions in order to address the prevailing situation adequately.

Risk factors of early childhood caries in a Southeast Asian population.

A retrospective cohort study on ECC and associated factors was conducted among mothers with 25- to 30-month-old infants in a community where prolonged breastfeeding was common practice. All infants who consumed sugary supplementary food or rice that was pre-chewed by the mother, or who fell asleep with the breast nipple in their mouths, had ECC. Infants without those habits, and who were breastfed up to 12 months, had no ECC. Breastfeeding during the day beyond the age of 12 months was not associated with ECC, but infants who were breastfed at night > 2 times had an OR for ECC of 35 (CI 6-186), and those who were exposed to > 15 min per nocturnal feeding had an OR for ECC of 100 (CI 10-995). The present study indicates that, in this population, besides the consumption of sugars and pre-chewed rice, nocturnal breastfeeding after the age of 12 months poses a risk of developing ECC.

Survival of ART and amalgam restorations in permanent teeth of children after 6.3 years.

The null hypothesis tested was that there is no difference in the survival percentages of all restorations placed through the Atraumatic Restorative Treatment (ART) approach, with high-viscosity glass ionomer, and those produced through the traditional approach, with amalgam (TA), in the permanent dentitions of children after 6.3 years. Using a parallel group design, we randomly assigned a total of 370 children, aged 6 to 9 years, to the ART group and 311 children, also aged 6 to 9 years, to the TA group. Eight dentists placed a total of 1117 single- and multiple-surface restorations. The cumulative survival percentages for ART glass-ionomer restorations were statistically significantly higher than those of amalgam restorations at all time intervals except the first (p < or = 0.044). After 6.3 years, the cumulative survival percentages of ART and amalgam restorations were 66.1% (SE = 3.1%) and 57.0% (SE = 3.3%), respectively. We concluded that the restorations produced with the ART approach, with high-viscosity glass ionomer, survived longer than those produced with the traditional approach, with amalgam, in the permanent teeth of young children.

Implant surface roughness and bone healing: a systematic review.

A systematic review was performed on studies investigating the effects of implant surface roughness on bone response and implant fixation. We searched the literature using MEDLINE from 1953 to 2003. Inclusion criteria were: (1) abstracts of animal studies investigating implant surface roughness and bone healing; (2) observations of three-month bone healing, surface topography measurements, and biomechanical tests; (3) provision of data on surface roughness, bone-to-implant contact, and biomechanical test values. The literature search revealed 5966 abstracts. There were 470, 23, and 14 articles included in the first, second, and third selection steps, respectively. Almost all papers showed an enhanced bone-to-implant contact with increasing surface roughness. Six comparisons were significantly positive for the relationship of bone-to-implant contact and surface roughness. Also, a significant relation was found between push-out strength and surface roughness. Unfortunately, the eventually selected studies were too heterogeneous for inference of data. Nevertheless, the statistical analysis on the available data provided supportive evidence for a positive relationship between bone-to-implant contact and surface roughness.

Plaque removal by young children using old and new toothbrushes.

There is inconclusive evidence about the relationship between toothbrush wear and plaque removal. This randomized cross-over clinical trial aimed to validate or invalidate non-inferiority in the plaque-removal efficacy of old vs. new toothbrushes in the hands of 7- and 8-year-old children. The lower limit for non-inferiority was set a priori as a difference in plaque score<15%. Children (n=101) brushed, in the first session, with either their 14-month-old toothbrush or a new one, and in the second session vice versa. The mean Quigley-Hein plaque score, before and after children brushed with old brushes, was 2.9 and 2.4, and with new brushes 2.8 and 2.1. The plaque score after they brushed with the new toothbrush was 10.9% lower (p<0.001) than after they brushed with the old toothbrush. The confidence interval of 7.6%-13.9% was within the acceptance band (<15%), and non-inferiority of old toothbrushes in the hands of these children was validated.

Caries-inhibiting effect of chlorhexidine varnish in pits and fissures.

Evidence regarding the caries-inhibiting effect of chlorhexidine varnish is inconclusive. This study investigated the caries-inhibiting effect of the varnish EC40 on pits and fissures of first permanent molars. A two-year randomized controlled trial was carried out among 461 six- to seven-year-old children. In a split-mouth design, one group of molars received EC40 at baseline, 6, 12, and 18 months, and another group at baseline, 3, 12, and 15 months. Control molars did not receive EC40. Adherence to the treatment protocol was good. The dropout rate was 17%. Blinded examiners performed dental examinations. The caries-inhibiting effects of the two EC40 application schemes were comparable. The prevented fraction of caries was 25% (95%CI, 1%, 49%, p = 0.04) after 2 years and 9% (95%CI, -11%, 29%, p = 0.20) one year after termination of the trial, suggesting a short-term benefit from the use of EC40. The efficiency of EC40 is questionable in low-caries-incidence child populations.

Caries-preventive effect of resin-based and glass ionomer sealants over time: a systematic review.

INTRODUCTION: The difference in preventing dentine lesion development between resin-based and glass ionomer sealant materials is unclear. Two recently published reviews were unable to conclude on the difference because the comparison was an exclusion criterion in one review and there were statistical shortcomings in the relevant papers in the other (Cochrane) review. OBJECTIVES: The aim of the present investigation was to carry out a systematic review on the caries-preventive effect of these two types of sealant materials under more liberal exclusion criteria concerning the statistical presentations in the publications. METHODS: Based on five exclusion criteria, the literature search in the electronic libraries PubMed and MEDLINE and the publications retrieved in the Cochrane review, revealed 12 eligible publications for analyses. A variety of glass ionomers and resin-based sealant materials had been applied in the included studies. Attributable risk (AR) was chosen rather than relative risk (RR), as used in the Cochrane review, because RR is very instable in a low caries population. RESULTS: There was no consistent pattern observed with respect to the caries-preventive effect of either resin-based or glass ionomer sealants. Therefore, it was impossible to calculate an overall AR. CONCLUSIONS: There is no evidence that either resin-based or glass ionomer sealant material is superior to the other in preventing dentine lesion development in pits and fissures over time.

Objective measures as indicators for facial esthetics in white adolescents.

The objective of this study was to examine the contribution of objective measures representing anterior-posterior and vertical characteristics, dental esthetics, or their combination that are used in daily orthodontic practice in the assessment of facial esthetics. A panel of 78 laymen evaluated facial esthetics of 32 boys and 32 girls, stratified over the four Angle classes, on a visual analogue scale. The relation between the objective parameters and facial esthetics was evaluated by backward multiple regression analysis. Dental esthetics as expressed by the Aesthetic Component of the Index of Orthodontic Treatment Need (AC/IOTN) appeared to be the most important indicator for facial esthetics. A new parameter, the "horizontal sum" was found to be a reliable variable for the anterior-posterior characteristics of the patient. Addition of this newly defined parameter to the AC/IOTN improved the prognostic value from 25% to 31%.

Professionally applied fluoride gel in low-caries 10.5-year-olds.

The question has been raised whether low-caries children regularly using fluoride toothpaste will benefit from the professional application of additional fluoride gel. To investigate the caries-reducing effect of semi-annually-applied neutral 1% sodium fluoride gel, we carried out a double-blind randomized controlled clinical trial (n = 594) in a child population, initially aged 9.5-11.5 years, with baseline caries experience of D3MFS = 0 (decayed, missing, and filled tooth surfaces of permanent teeth). The mean number of tooth surfaces saved from caries development by fluoride gel application after 4 years was 0.2 D3MFS (SE = 0.17). The preventive fraction (PF) showed a mean relative effect of professionally applied fluoride gel of 18%. The cariostatic effect of the fluoride gel on pits and fissures would have been influenced by the sealant strategy in the study. Professionally applied fluoride gel showed no statistically significant effect on mean D3MFS score in low-caries 9.5- to 11.5-year-olds.

Stabilisation of sagittal split set-back osteotomies with miniplates: a prospective, multicentre study with 2-year follow-up.

The aim of this study was to assess post-operative stability of bilateral sagittal split set-back osteotomies using two miniplates and clinical parameters including nerve function, TMJ function, occlusal relapse and patient satisfaction. The stability was measured on cephalometric radiographs and possible condylar alterations on orthopantomograms. This prospective study implied a 2-year follow-up on a group of 24 patients. The same protocol was used at six participating institutions at which the patients were treated. A stable occlusion without appreciable relapse was seen in 91% after 2-year follow-up. Only two patients in this study had mild occlusal relapse. The mean skeletal horizontal relapse at pogonion of the whole group, after 2 years was 1.1mm and appeared to be directed backwards. At occlusal level, however, the mean relapse was 1.2mm forwards. The function of the inferior alveolar nerve 2 years post-operatively was reported to be normal in approximately 70% of the patients, yet 80% had no complaints about nerve dysaesthesia. In approximately 21% of the patients, signs and symptoms of TMJ dysfunction had disappeared. Another group (10%), however, without pre-operative signs and symptoms of TMJ dysfunction developed these signs or symptoms post-operatively. No condylar remodelling or resorption was seen in this group of patients. The sagittal split set-back osteotomy fixed with miniplates appeared to be a relatively save and reliable procedure giving rise to adequate results and a high degree of patients satisfaction.

[Implant-retained overdentures compared with complete dentures with or without preprosthetic surgery. A prospective study followed over 10 years]. / Overkappingsprothese op implantaten versus volledige prothese zonder en met mondbodemvestibulumplastiek. Een prospectief onderzoek van 10 jaar.

The aim of this prospective randomized clinical trial was to evaluate and compare a set of clinical items and satisfaction of a group of edentulous patients during a ten-year follow-up. They were treated according to one of the following modalities: 61 patients with a mandibular overdenture on two implants (IMP-group), 60 patients with conventional complete dentures (VP-group) and 28 patients with a complete denture after preprosthetic surgery (MVP-group). It can be concluded that enosseous implants, serving as retention for a mandibular overdenture, have a high survival rate after ten years of follow-up (93%). The mean satisfaction score of the VP-group was lower than that of the IMP-group. The mean satisfaction score of the MVP-group was lower than that of the IMP-group.

Pubertal maturation characteristics and the rate of bone mass development longitudinally toward menarche.

To assess risks for osteoporosis and to compare bone mass in different groups of healthy children or children with diseases, it is important to have knowledge of their sexual maturation status during puberty. The aim of our study was to evaluate bone mass formation longitudinally in relation to pubertal maturation characteristics in healthy white girls. We investigated the bone mineral content (BMC) and the bone mineral density (BMD) at different skeletal sites in 151 girls with increasing pubertal stages in relation with their chronological age and with an early or late onset of puberty or menarche and with a slow or fast maturation. Bone mass was measured at the onset of puberty, during puberty, and at menarche. We conclude the following: (1) from midpuberty to menarche, the increase in bone mass formation is highest at all skeletal sites in white girls; (2) early mature girls at the onset of puberty have slightly but definitely lower bone masses at all skeletal sites and at all pubertal stages than late mature girls, whereas the average bone mass formation from the onset of puberty to menarche is similar in both groups; (3) girls with a slow rate of pubertal maturation have lower bone mass values 2 years after the onset of puberty, but at menarche bone mass is similar compared with fast maturers; and (4) it cannot be confirmed that there is an effect of menarcheal age on bone mass values at menarche.

Enhanced resistance to oxidation of low density lipoproteins and decreased lipid peroxide formation during beta-carotene supplementation in cystic fibrosis.

We investigated the effect of correcting beta-carotene deficiency in cystic fibrosis (CF) patients on two parameters of lipid peroxidation. The resistance to oxidation of low density lipoprotein (LDL) was measured by the lag time preceding the onset of conjugated diene formation during exposure to copper(II) ions, and lipid peroxide formation was quantitated by malondialdehyde concentrations in plasma (TBA/HPLC method). Simultaneously, alpha-tocopherol and beta-carotene concentrations were determined in LDL and in plasma. Thirty-four CF patients were investigated before and after 3 months of oral beta-carotene supplementation. Beta-carotene concentrations increased (p < 0.0001) in plasma (mean +/- SD) (0.09 +/- 0.06 vs. 1.07 +/- 0.86 mumol/l) and in LDL (0.02 +/- 0.02 vs. 0.31 +/- 0.28 mol/mol), without significant changes in alpha-tocopherol, either in plasma (24.7 +/- 5.9 vs. 25.4 +/- 7.6) or in LDL (8.47 +/- 2.95 vs. 9.05 +/- 4.13). Lag times, being shorter (p < 0.05) in patients than in controls, increased from 48.5 +/- 21.3 to 69.1 +/- 27.9 min (p < 0.001) and plasma MDA concentrations, being greater (p < 0.0001) in patients than in controls, decreased from 0.95 +/- 0.32 to 0.61 +/- 0.15 mumol/l (p < 0.0001). At 3 months, lag times and MDA concentrations did not any longer differ between patients and controls. These data suggest that excess lipid peroxidation occurring in beta-carotene deficiency can be limited and normalized during efficient beta-carotene supplementation in CF patients.

Impaired resistance to oxidation of low density lipoprotein in cystic fibrosis: improvement during vitamin E supplementation.

Antioxidants such as vitamin E protect unsaturated fatty acids of LDL against oxidation. In the ex vivo model used, LDL was exposed to Cu2+ ions, a potent prooxidant capable of initiating the oxidation of LDL. The lag time, indicating the delay of conjugated diene formation in LDL due to antioxidant protection, was measured in 54 cystic fibrosis (CF) patients with plasma alpha-tocopherol levels below (Group A, n = 30) or above (Group B, n = 24) 15.9 mumol/L (mean - 2 SD of Swiss population). Patients were reevaluated after 2 months on 400 IU/d of oral RRR-alpha-tocopherol. In group A, alpha-tocopherol concentrations in LDL increased significantly from 3.2 +/- 1.6 mol/mol LDL to 8.2 +/- 2.8 mol/mol (P < 0.001) and lag times increased from 79 +/- 33 min to 126 +/- 48 min (P < 0.001), whereas in the vitamin E sufficient group B no further increase neither in LDL alpha-tocopherol concentrations or in lag times was observed. LDL oleic acid concentrations were higher, and linoleic acid concentrations were lower in patients than in controls. After efficient vitamin E supplementation, lag times were positively related to LDL alpha-tocopherol (P < 0.01) and negatively to LDL linoleic and arachidonic acid content (P < 0.001). The maximum rate of oxidation correlated positively with linoleic and arachidonic acid concentrations, as did the maximum conjugated diene absorbance. These results indicate that LDL resistance to oxidation is impaired in vitamin E deficient CF patients but can be normalized within 2 months when alpha-tocopherol is given in sufficient amounts. Linoleic and arachidonic acid content exhibit a major influence on the LDL resistance to oxidation.

Effects of pancreatic enzyme preparations on erythrocyte glutathione peroxidase activities and plasma selenium concentrations in cystic fibrosis.

To substitute for exocrine pancreatic insufficiency, patients with cystic fibrosis (CF) take pancreatic enzymes (PE) originating from porcine pancreas. Five different pancreatic enzyme preparations used by our patients contained 0.5-1.4 microg selenium per g tablet. In patients taking PE in doses that were gradually increased to improve fat absorption during a 48-month period, the effects of PE dose on erythrocyte selenium-dependent glutathione peroxidase (SeGSH-Px) activities and plasma selenium concentrations were studied. At baseline, erythrocyte SeGSH-Px activities were significantly lower in patients (p=.01), while plasma selenium concentrations did not differ between patients and healthy subjects. When PE dose and, consequently, selenium intake from PE was increased, erythrocyte SeGSH-Px activities (p < .001) and plasma selenium concentrations (p=.02) increased. Changes in SeGSH-Px activities during the initial 8 months correlated with those in selenium intake from PE (r=0.67, p < .001). Plasma selenium concentrations plateaued at 12 months and erythrocyte SeGSH-Px activities did so at 36 months, when patients had reached SeGSH-Px activities similar to those of healthy subjects. At 48 months, patients took an average lipase dose of 17400 U x kg(-1) x d(-1) and selenium dose from PE of 0.53 microg x kg(-1) x d(-1). We conclude that selenium content of PE preparations has a significant effect on SeGSH-Px activity in patients with CF. This form of selenium supply needs to be taken into account when selenium supplements are given to patients with CF.

Long-term oral vitamin E supplementation in cystic fibrosis patients: RRR-alpha-tocopherol compared with all-rac-alpha-tocopheryl acetate preparations.

To investigate the efficacy of three different vitamin E preparations for optimizing vitamin E status in cystic fibrosis (CF patients long-term, 29 patients (aged 0.7-29.8 y) were randomly assigned to receive 400 IU of either RRR-alpha-tocopherol (A: 268 mg, n = 10) or all rac-alpha-tocopheryl acetate as a fat-soluble (B: 400 mg, n = 10) or water-miscible preparation (C: 400 mg, n = 9) and were followed for 6 wk. In the whole study group, plasma alpha-tocopherol concentrations increased from baseline (10.5 +/- 4.6 micromol/L) to 3 wk (25.7 +/- 6.5 micromol/L; P < 0.001), but not further between 3 and 6 wk; concentrations at 3 and 6 wk did not differ from those of age-matched control subjects (23.6 +/- 3.9 micromol/L). There was no significant difference in the increase from baseline to 6 wk among preparations A (17.75 +/- 8.43 micromol/L), B (14.0 +/- 9.4 micromol/L), and C (15.5 +/- 7.1 micromol/L). Because of differences in body weight, the dose administered ranged from 5.5 to 47.4 IU x kg-1 x d-1; it correlated positively with the increase in plasma alpha-tocopherol concentrations (P < 0.001). There was no significant difference in the increase in plasma alpha-tocopherol concentrations between patients with CF-associated liver disease (n = 8) who received 10.2 +/- 3.8 IU x kg-1 x d-1 and those without liver disease taking comparable doses. We conclude that CF patients can be efficiently supplemented with 400 IU/d of any one of the three vitamin E preparations and plasma values of healthy control subjects can be achieved.

Plasma vitamin C concentrations in patients with cystic fibrosis: evidence of associations with lung inflammation.

Vitamin C status and possible associations with the disease process in cystic fibrosis (CF) patients were investigated. Plasma vitamin C concentrations in patients from two different mid-European populations (Swiss, n = 62; Austrian, n = 60) taking no or low-dose vitamin C from multivitamin supplements did not differ from each other or from control subjects (n = 34). Vitamin C concentrations decreased with age (5.05 mumol.L-1, y-1). When followed up for 12 mo, patients had the highest plasma vitamin C concentrations in February and the lowest in May and August (P < 0.01); the decrease in vitamin C was accompanied by increases in plasma malondialdehyde (P < 0.001) and tumor necrosis factor alpha concentrations (P < 0.01). During supplementation with vitamin E for 2 mo or beta-carotene for 12 mo vitamin C concentrations did not change. They correlated inversely with white blood cell count (r = -0.36, P = 0.008), bands (r = -0.36, P = 0.02), alpha 1-acid glycoprotein (r = -0.45, P = 0.002), interleukin 6 (r = -0.46, P = 0.0006), and neutrophil elastase/alpha 1-proteinase inhibitor complexes (r = -0.34, P = 0.02). In patients with vitamin C concentrations < 40 mumol/L, all indexes of inflammation were relatively high, whereas those with concentrations > 80 mumol/L (upper quartile of control subjects) showed clearly lower values. These results are consistent with the hypothesis that by scavenging oxygen free radicals vitamin C interacts with an inflammation-amplifying cycle of activation of alveolar macrophages and neutrophils, release of proinflammatory cytokines and oxygen free radicals, and inactivation of antiproteases.