Vitamin D status in longstanding type 1 diabetes and controls. Association with upper extremity impairments.

Background: Patients with type 1 diabetes have a high prevalence of upper extremity impairments (UEIs), such as frozen shoulder, carpal tunnel syndrome, and trigger finger. The UEIs are strongly associated with activity limitations and impaired quality of life. The etiology of the UEI is not clear. Vitamin D deficiency has been considered to play a role in the pathogenesis of type 1 diabetes and in the development of macro- and microvascular complications in diabetes. Aim: To characterize vitamin D status in a large population of patients with type 1 diabetes, if vitamin D deficiency is associated with metabolic factors and possible association with UEI. Material and methods: Patients who diagnosed before 35 years of age, whose diabetes duration >20 years, and who are not older than 65 years were invited to participate in this cross-sectional case-control, multicenter study. Controls matched for age and sex were obtained from the national population registry. Fasting blood samples were collected and stored at -80°C until analyzed regarding 25-hydroxy-vitamin D (25(OH)D3) by a liquid chromatographic-mass spectrometric method (LC-MS/MS). Results: Vitamin D levels varied with season as expected in the northern hemisphere. The association between 25(OH)D3 and clinical variables was analyzed in a univariate general linear model, which indicated no difference in 25(OH)D3 in men with and without diabetes but higher values in women with diabetes. About 30% of both patients and controls had vitamin D deficiency (≤50 nmol/L). Analyzed by binary logistic regression UEIs was not associated with 25(OH)D3 levels. In both patients and controls, 25(OH)D3 was correlated to apolipoprotein A1 (r = 0.153; 0.220, P < 0.001). Conclusion: In patients with type 1 diabetes and a duration of 20 years or more, vitamin D level is not lower than in nondiabetic controls and is not associated with UEIs.

Imidacloprid Induces Lysosomal Dysfunction and Cell Death in Human Astrocytes and Fibroblasts-Environmental Implication of a Clinical Case Report.

Imidacloprid (IMI), a neonicotinoid insecticide, has potential cytotoxic and genotoxic effects on human and experimental models, respectively. While being an emerging environmental contaminant, occupational exposure and related cellular mechanisms are unknown. Herein, we were motivated by a specific patient case where occupational exposure to an IMI-containing plant protection product was associated with the diagnosis of Bell's palsy. The aim was to investigate the toxic effects and cellular mechanisms of IMI exposure on glial cells (D384 human astrocytes) and on human fibroblasts (AG01518). IMI-treated astrocytes showed a reduction in cell number and dose-dependent cytotoxicity at 24 h. Lower doses of IMI induced reactive oxygen species (ROS) and lysosomal membrane permeabilisation (LMP), causing apoptosis and autophagic dysfunction, while high doses caused significant necrotic cell death. Using normal fibroblasts, we found that IMI-induced autophagic dysfunction and lysosomal damage, activated lysophagy, and resulted in a compensatory increase in lysosomes. In conclusion, the observed IMI-induced effects on human glial cells and fibroblasts provide a possible link between IMI cytotoxicity and neurological complications observed clinically in the patient exposed to this neonicotinoid insecticide.

The Effects of Dairy and Plant-Based Liquid Components on Lutein Liberation in Spinach Smoothies.

Lutein is a dietary lipophilic compound with anti-inflammatory properties. We have previously shown that dairy fat can improve the lutein content in spinach smoothies. It is, however, unclear whether fat concentrations and fermentation status in dairy products affect lutein liberation in smoothies. Moreover, plant-based milks vary in fat, protein, and fiber content which may affect lutein dissolution. This study aimed to provide translatable information to consumers by comparing lutein liberation in spinach smoothies made with different dairy or plant-based liquids in domestic settings. The smoothies were digested in vitro, and liberated lutein was measured by high-performance liquid chromatography (HPLC). High-fat and medium-fat cow's milk, as well as coconut milk with and without additives, were found to significantly improve lutein liberation by 36%, 30%, 25%, and 42%, respectively, compared to blending spinach with water alone. Adjustment models suggested that the effects of cow's milk and coconut milk were derived from fat and protein, respectively. On the other hand, soymilk with and without additives showed significantly reduced lutein liberation by 40% and 61%, respectively. To summarize, only 4 out of 14 tested liquids increased lutein liberation in spinach smoothies. The results highlight the importance of testing food companions for lipophilic active ingredients.

The effect of acute exercise on interleukin-6 and hypothalamic-pituitary-adrenal axis responses in patients with coronary artery disease.

Vulnerability to stress-induced inflammation has been linked to a dysfunctional hypothalamus-pituitary-adrenal (HPA) axis. In the present study, patients with known or suspected coronary artery disease (CAD) were assessed with respect to inflammatory and HPA axis response to acute physical exercise. An exercise stress test was combined with SPECT myocardial perfusion imaging. Plasma and saliva samples were collected before and 30 min after exercise. Interleukin (IL)-6 and adrenocorticotropic hormone (ACTH) were measured in plasma, while cortisol was measured in both plasma and saliva. In total, 124 patients were included of whom 29% had a prior history of CAD and/or a myocardial perfusion deficit. The levels of exercise intensity and duration were comparable in CAD and non-CAD patients. However, in CAD patients, IL-6 increased after exercise (p = 0.019) while no differences were seen in HPA axis variables. Conversely, patients without CAD exhibited increased levels of ACTH (p = 0.003) and cortisol (p = 0.004 in plasma, p = 0.006 in saliva), but no change in IL-6. We conclude that the IL-6 response to acute physical exercise is exaggerated in CAD patients and may be out of balance due to HPA axis hypoactivity. It remains to be further investigated whether this imbalance is a potential diagnostic and therapeutic target in CAD.

Combined vitamin D, ibuprofen and glutamic acid decarboxylase-alum treatment in recent onset Type I diabetes: lessons from the DIABGAD randomized pilot trial.

AIM: Double-blind placebo-controlled intervention using glutamic acid decarboxylase (GAD)-alum, vitamin D and Ibuprofen in recent onset Type I diabetes (T1D). METHODS: 64 patients (T1D since <4 months, age 10-17.99, fasting sC-peptide ≥0.12 nmol/l, GADA-positive) were randomized into Day(D) 1-90 400 mg/day Ibuprofen, D1-450 vitamin D 2000 IU/day, D15, 45 sc. 20 µg GAD-alum; as A but placebo instead of Ibuprofen; as B but 40 µg GAD-alum D15, 45; placebo. RESULTS: Treatment was safe and tolerable. No C-peptide preservation was observed. We observed a linear correlation of baseline C-peptide, HbA1c and insulin/per kilogram/24 h with change in C-peptide AUC at 15 months (r = -0.776, p < 0.0001). CONCLUSION: Ibuprofen, vitamin D + GAD-alum did not preserve C-peptide. Treatment efficacy was influenced by baseline clinical and immunological factors and vitamin D concentration. Clinical Trial Registration: NCT01785108 (ClinicalTrials.gov).

High levels of isocyanic acid in smoke generated during hot iron cauterization.

Pyrolysis of nitrogen containing biofuels generates isocyanic acid (ICA) and we here studied if ICA also is present in cauterization smoke. Air sampling was performed when animal technicians that had developed airway symptoms worked with dehorning. Tissue heated in a laboratory model was used to mimic cauterization. ICA in air at the workplace exceeded 10 times the national exposure limit. In the laboratory, the ICA generated per mg tissue from heated hair, horn and nail was 13.9 ± 7.8, 24.0 ± 4.1 and 32.0 ± 2.9 µg, respectively. Three workers were medically examined and two were diagnosed with asthma and a third had severe airway problem that resembled asthma. The study shows that high levels of ICA are generated during cauterization of nitrogen-containing tissue. If this could trigger airway symptoms deserves to be investigated further.

Use of a Web-Based Dietary Assessment Tool (RiksmatenFlex) in Swedish Adolescents: Comparison and Validation Study.

BACKGROUND: A Web-based dietary assessment tool-RiksmatenFlex-was developed for the national dietary survey of adolescents in Sweden. OBJECTIVE: This study aimed to describe the Web-based method RiksmatenFlex and to test the validity of the reported dietary intake by comparing dietary intake with 24-hour dietary recalls (recall interviews), estimated energy expenditure, and biomarkers. METHODS: Adolescents aged 11-12, 14-15, and 17-18 years were recruited through schools. In total, 78 students had complete dietary information and were included in the study. Diet was reported a few weeks apart with either RiksmatenFlexDiet (the day before and a random later day) or recall interviews (face-to-face, a random day later by phone) in a cross-over, randomized design. At a school visit, weight and height were measured and blood samples were drawn for biomarker analyses. Students wore an accelerometer for 7 days for physical activity measurements. Dietary intake captured by both dietary methods was compared, and energy intake captured by both methods was compared with the accelerometer-estimated energy expenditure (EEest). Intake of whole grain wheat and rye and fruit and vegetables by both methods was compared with alkylresorcinol and carotenoid concentrations in plasma, respectively. RESULTS: The mean of the reported energy intake was 8.92 (SD 2.77) MJ by RiksmatenFlexDiet and 8.04 (SD 2.67) MJ by the recall interviews (P=.01). Intake of fruit and vegetables was 224 (169) g and 227 (150) g, and whole grain wheat and rye intake was 12.4 (SD 13.2) g and 12.0 (SD 13.1) g, respectively; the intakes of fruit and vegetables as well as whole grain wheat and rye did not differ between methods. Intraclass correlation coefficients ranged from 0.57 for protein and carbohydrates to 0.23 for vegetables. Energy intake by RiksmatenFlexDiet was overreported by 8% (P=.03) but not by the recall interviews (P=.53) compared with EEest. The Spearman correlation coefficient between reported energy intake and EEest was 0.34 (P=.008) for RiksmatenFlexDiet and 0.16 (P=.21) for the recall interviews. Spearman correlation coefficient between whole grain wheat and rye and plasma total alkylresorcinol homologs was 0.36 (P=.002) for RiksmatenFlexDiet and 0.29 (P=.02) for the recall interviews. Spearman correlations between intake of fruit and vegetables and plasma carotenoids were weak for both dietary tools. The strongest correlations were observed between fruit and vegetable intake and lutein/zeaxanthin for RiksmatenFlexDiet (0.46; P<.001) and for recall interviews (0.28; P=.02). CONCLUSIONS: RiksmatenFlexDiet provides information on energy, fruit, vegetables, and whole grain wheat and rye intake, which is comparable with intake obtained from recall interviews in Swedish adolescents. The results are promising for cost-effective dietary data collection in upcoming national dietary surveys and other studies in Sweden. Future research should focus on how, and if, new technological solutions could reduce dietary reporting biases.

Isocyanates and hydrogen cyanide in fumes from heated proteins and protein-rich foods.

Toxic compounds in cooking fumes could cause respiratory problems. In the present study, the formation of isocyanic acid (ICA), methyl isocyanate (MIC), and hydrogen cyanide (HCN) was studied during the heating of proteins or frying of protein-rich foods. Heating was performed in an experimental setup using a tube oven set at 200-500°C and in a kitchen when foods with different protein content were fried at a temperature around 300°C. ICA, MIC, and HCN were all generated when protein or meat was heated. Individual amino acids were also heated, and there was a significant positive correlation between their respective nitrogen content and the formation of the measured compounds. Gas from heated protein or meat also caused carbamylation in albumin. ICA, MIC, and HCN were also present in fumes generated when meat, egg, and halloumi were fried in a kitchen pan. The levels of ICA were here twice that of the Swedish occupational exposure limit. If ICA, MIC, and HCN in fumes from heated protein-rich foods could contribute to the risk of airway dysfunction among those exposed is not clear, but it is important to avoid inhaling frying and grilling fumes and to equip kitchens with good exhaust ventilation.

Liberation of lutein from spinach: Effects of heating time, microwave-reheating and liquefaction.

Lutein, abundant in dark leafy vegetables, has been associated with several health promoting effects. Still, to what extent different preparation conditions and practices affect the liberation of lutein from food is not fully understood. Here, we compared a range of domestic methods under realistic conditions to prepare spinach, the most common lutein-rich vegetable. After preparations, samples were processed by in vitro digestion and lutein was quantified by HPLC. Data indicate that short-term and medium-term heating of spinach, independent of heating method, substantially reduced liberated lutein and reduction was most pronounced after long boiling times. Interestingly, the loss of lutein in heated samples was partly compensated when samples were reheated in the microwave. However, the highest yield of liberated lutein was obtained from liquefied spinach. Additional dairy enhanced the liquefaction effect. Thus, for optimal liberation of lutein, liquefaction of raw spinach appears to be the method of choice.

The influence of disease severity and lifestyle factors on the peak annual 25(OH)D value of COPD patients.

BACKGROUND: The prevalence of individuals deficient in vitamin D (defined as a serum level of the stable metabolite 25(OH)D <50 nmol/L) is increasing in countries with low annual ultraviolet (UV) radiation and among individuals unable to perform outdoor activities, for example, COPD patients. OBJECTIVE: To assess the role of vitamin D deficiency, independently of seasonal variation, the peak annual value of 25(OH)D was measured in subjects with advanced COPD ± long-term oxygen therapy (LTOT) and lung healthy control subjects. A method to grade the individual annual UV light exposure was designed and tested. SUBJECTS AND METHODS: Sixty-six Caucasians with advanced COPD (28 with LTOT) and 47 control subjects were included, and the levels of 25(OH)D were determined in late summer/early fall when the annual peak was assumed. Questionnaires about COPD symptoms, general health, lifestyle, dietary habits and QoL were used to collect data. Lung function tests and blood sampling were performed. RESULTS: The peak annual 25(OH)D of COPD subjects was significantly lower than in the control subjects, but there was no significant difference between COPD patients with and without LTOT. Ongoing vitamin D supplementation was the single most important intervention to maintain 25(OH)D levels ≥50 nmol/L. Among vitamin D-deficient COPD subjects, 25(OH) D correlated positively with forced expiratory volume in 1 second as % predicted, Modified British Medical Research Council score, blood oxygenation, food portion size, Mediterranean Diet Score and Ultraviolet Score. CONCLUSION: Vitamin D deficiency was common among healthy individuals and COPD subjects. Peak annual 25(OH)D levels of COPD subjects correlated with clinically important outcomes. The present study emphasizes the need to routinely monitor vitamin D status among patients with advanced COPD and to consider to medicate those with vitamin D deficiency with vitamin D supplementation.

A randomised study in young subjects of the effects of eating extra fruit or nuts on periodontal inflammation.

OBJECTIVES/AIMS: Fruit is often advocated as a healthy source of nutrients and vitamins. However, the high contents of sugars in many fruits could potentially counteract positive effects on the teeth. MATERIALS AND METHODS: We recruited 30 healthy non-obese participants who were randomised to either supplement their diet with extra fruits or nuts, each at +7 kcal/kg body weight/day, for 2 months. RESULTS: Fructose intake increased from 9.1±6.0 to 25.6±9.6 g/day, P<0.0001, in the fruit group and was reduced from 12.4±5.7 to 6.5±5.3 g/day, P=0.007, in the nut group. Serum-vitamin C increased in both groups (fruit: P=0.017; nuts: P=0.009). α-Tocopherol/cholesterol ratio increased in the fruit group (P=0.0033) while ß-carotene/cholesterol decreased in the nut group (P<0.0001). The amount of subjects with probing pocket depths ⩾4 mm in the fruit group was reduced (P=0.045) according to blinded examinations, and the difference in the changes in probing pockets ⩾4 mm was also statistically significant between the food groups (P=0.010). CONCLUSION: A large increase of fruit intake, compared with nuts, had a favourable effect on periodontal status in some respects, despite the high sugar contents. To search for potential protective micronutrients in fruit that protect the teeth could be an aim for further research.

Lutein exerts anti-inflammatory effects in patients with coronary artery disease.

BACKGROUND AND AIMS: Many coronary artery disease (CAD) patients exhibit chronic low-grade inflammation. Carotenoids are anti-oxidants with potential anti-inflammatory properties. Here, we first assessed relationships between interleukin (IL)-6 and individual carotenoids in plasma from CAD patients. Based on the results, we proceeded to assess anti-inflammatory effects of one carotenoid, lutein, in peripheral blood mononuclear cells (PBMCs) from CAD patients. METHODS: Lutein + zeaxanthin (isomers with lutein being dominant), ß-cryptoxanthin, lycopene, α- and ß-carotene and IL-6 were measured in plasma from 134 patients with stable angina (SA) and 59 patients with acute coronary syndrome. In 42 patients, plasma measurements were also performed 3 months after coronary intervention. PBMCs from SA patients were pre-treated with lutein (1, 5 and 25 µM) for 24 h followed by 24 h incubation ± lipopolysaccharide (LPS). Cell pellets were collected for IL-6, IL-1ß and TNF mRNA and intracellular lutein. Cytokine secretion was measured in cell media. RESULTS: Only lutein + zeaxanthin were inversely correlated with IL-6 in SA patients at baseline (r = -0.366, p < 0.001) and follow-up (r = -0.546, p < 0.001). Ex vivo, lutein was taken up by PBMCs from SA patients in a dose- and time-dependent manner. Pre-treatment with lutein dose-dependently lowered LPS-induced secretion of IL-6, IL-1ß (p < 0.01) and TNF (p < 0.05), and also reduced IL-6, IL-1ß and TNF mRNA expression (p < 0.05). CONCLUSIONS: Clinical findings highlighted the inverse association between lutein and IL-6 in CAD patients. Anti-inflammatory effects of lutein in PBMCs from CAD patients were consolidated in ex vivo experiments. Taken together, these results show that lutein has the potential to play a role in resolution of chronic inflammation in CAD patients.

Airway symptoms and biological markers in nasal lavage fluid in subjects exposed to metalworking fluids.

BACKGROUNDS: Occurrence of airway irritation among industrial metal workers was investigated. The aims were to study the association between exposures from water-based metal working fluids (MWF) and the health outcome among the personnel, to assess potential effects on the proteome in nasal mucous membranes, and evaluate preventive actions. METHODS: The prevalence of airway symptoms related to work were examined among 271 metalworkers exposed to MWF and 24 metal workers not exposed to MWF at the same factory. At the same time, air levels of potentially harmful substances (oil mist, morpholine, monoethanolamine, formaldehyde) generated from MWF was measured. Nasal lavage fluid was collected from 13 workers and 15 controls and protein profiles were determined by a proteomic approach. RESULTS: Airway symptoms were reported in 39% of the workers exposed to MWF although the measured levels of MWF substances in the work place air were low. Highest prevalence was found among workers handling the MWF machines but also those working in the same hall were affected. Improvement of the ventilation to reduce MWF exposure lowered the prevalence of airway problems. Protein profiling showed significantly higher levels of S100-A9 and lower levels of SPLUNC1, cystatin SN, Ig J and ß2-microglobulin among workers with airway symptoms. CONCLUSIONS: This study confirms that upper airway symptoms among metal workers are a common problem and despite low levels of MWF-generated substances, effects on airway immune proteins are found. Further studies to clarify the role of specific MWF components in connection to airway inflammation and the identified biological markers are warranted.

Eating buckwheat cookies is associated with the reduction in serum levels of myeloperoxidase and cholesterol: a double blind crossover study in day-care centre staffs.

Buckwheat food is a good source of antioxidants, e.g. rutin, and other beneficial substances. Here we investigated the effects of the intake of common buckwheat (low rutin content) and tartary buckwheat cookies (high rutin content) on selected clinical markers. A double blind crossover study was performed among female day-care centre staffs (N = 62) from five day-care centres. Participants were randomly divided into two groups. The first group initially consumed four common buckwheat cookies per day (16.5 mg rutin equivalents/day) for two weeks, while the second group consumed four tartary buckwheat cookies per day (359.7 mg rutin equivalents/day). Then the groups switched their type of cookies and consumed them for another two weeks. We monitored selected clinical markers related to cardiovascular disease and lower airway inflammation, lung function, and subjective breathing difficulties in the staffs. Intake of tartary buckwheat cookies reduced the serum level of myeloperoxidase (MPO) by a factor 0.84 (p = 0.02). When grouping the two types of buckwheat cookies together, there was a reduction of total serum cholesterol (p < 0.001) and HDL-cholesterol (p < 0.001) during the study period, with improved lung vital capacity (p < 0.001). The degree of reduction in total and HDL cholesterol levels was similar in staffs with low and high body mass index (cut off 25). In conclusion, intake of tartary buckwheat cookies with high level of the antioxidant rutin may reduce levels of MPO, an indicator of inflammation. Moreover, intake of both types of buckwheat cookies may lower cholesterol levels.

NK cell apoptosis in coronary artery disease: relation to oxidative stress.

OBJECTIVE: Natural killer (NK) cells, key elements in initiation and modulation of immune responses, were recently found to be reduced in coronary artery disease (CAD). To clarify mechanisms behind this reduction, we here investigated NK cell apoptosis in CAD patients. Since oxidative stress has been linked to NK cell apoptosis, we related the findings to oxidative stress in vivo and evaluated the ex vivo susceptibility of NK cells to oxidized lipids. METHODS AND RESULTS: The number of apoptotic NK cells in peripheral blood was significantly increased in CAD patients compared to controls. Purified NK cells from CAD patients also showed a higher rate of spontaneous apoptosis ex vivo. Dose- and time-dependent effects of oxidized LDL and 7beta-hydroxycholesterol (7betaOH) on apoptosis and ROS production were determined in NK cells from blood donors. Thereafter, purified NK cells from CAD patients and healthy controls were exposed to the oxidized lipids in a paired design. NK cells from patients were more susceptible to apoptosis induced by oxidized LDL, in particular 7betaOH, compared to cells from controls. Plasma measurements of LDL protein oxidation and lipid peroxidation did not show any differences between patients and controls. On the other hand, plasma carotenoids were significantly decreased in patients and inversely correlated to NK cell apoptosis rate. CONCLUSION: The rate of spontaneous NK cell apoptosis was increased in CAD patients. Although NK cells in CAD patients were more sensitive to oxidized lipids ex vivo, indicating a mechanism contributing to the reduced NK cell activity in CAD, the data could not verify an obvious link between NK cell apoptosis and increased oxidative stress in vivo.

Low plasma levels of oxygenated carotenoids in patients with coronary artery disease.

BACKGROUND AND AIMS: Low circulating levels of carotenoids have been associated with cardiovascular disease. The distribution of different carotenoids in blood may have an impact on the cardioprotective capacity. The aim of the present study was to determine the plasma levels of 6 major carotenoids in patients with coronary artery disease (CAD) and relate the findings to clinical, metabolic and immune parameters. METHODS AND RESULTS: Plasma levels of oxygenated carotenoids (lutein, zeaxanthin, beta-cryptoxanthin) and hydrocarbon carotenoids (alpha-carotene, beta-carotene, lycopene) were determined in 39 patients with acute coronary syndrome, 50 patients with stable CAD and 50 controls. Serological assays for inflammatory activity and flow cytometrical analysis of lymphocyte subsets were performed. Both patient groups had significantly lower plasma levels of oxygenated carotenoids, in particular lutein+zeaxanthin, compared to controls. Low levels of oxygenated carotenoids were associated with smoking, high body mass index (BMI), low high density lipoprotein (HDL) cholesterol and, to a minor degree, inflammatory activity. Plasma levels of lutein+zeaxanthin were independently associated with the proportions of natural killer (NK) cells, but not with other lymphocytes, in blood. CONCLUSION: Among carotenoids, lutein+zeaxanthin and beta-cryptoxanthin were significantly reduced in CAD patients independent of clinical setting. The levels were correlated to a number of established cardiovascular risk factors. In addition, the relationship between NK cells and lutein+zeaxanthin may indicate a particular role for certain carotenoids in the immunological scenario of CAD.

Diurnal saliva cortisol levels and relations to psychosocial factors in a population sample of middle-aged Swedish men and women.

Whereas psychosocial risk factors increase the risk for disease, psychosocial resources reduce this risk. To examine a possible pathway for these effects, the relations between saliva cortisol levels and psychosocial factors were studied in a random sample of 257 men and women aged 30 to 64 years. Saliva samples were collected at home on waking, 30 min after waking, and in the evening. A flatter diurnal rhythm of cortisol, that is, lower deviations between awakening and evening cortisol levels, was related to high levels of psychosocial risk factors (cynicism, depression, and vital exhaustion), whereas a steeper diurnal rhythm was related to psychosocial resources (social support and coping), general health, and well-being (all p < .05). Our results support earlier suggestions that the capacity of the hypothalamic-pituitary-adrenal-axis to dynamically respond to stress is 1 pathway for observed effects of psychosocial factors regarding risk for disease development.

Cytocidal effects of atheromatous plaque components: the death zone revisited.

OBJECTIVE: Earlier we suggested that atheroma lesions constitute a "death zone" containing toxic materials that may cause dysfunction and demise of invading macrophages to prevent the removal of plaque materials. Here we have assessed the cytotoxic effects of nonfractionated gruel and insoluble (ceroid-like) material derived from advanced human atheroma. METHODS AND RESULTS: The insoluble material within advanced atherosclerotic plaque was isolated following protease K digestion and extensive extraction with aqueous and organic solvents. FTIR, Raman, and atomic absorption spectroscopy suggested that, despite its fluorescent nature, this material closely resembled hydroxyapatite and dentin, but also contained a significant amount of iron and calcium. When added to J774 cells and human macrophages in culture, this insoluble substance was phagocytosed, and progressive cell death followed. However, an even more cytotoxic activity was found in the atheromatous "gruel" that contains abundant carbonyls/aldehydes. Cell death caused by both crude gruel and ceroid could be blocked by preincubating cells with the lipophilic iron chelator salicylaldehyde isonicotinoyl hydrazone, apoferritin, BAPTA/AM, or sodium borohydride, indicating that cellular iron, calcium, and reactive aldehyde(s) are responsible for the observed cytotoxicity. CONCLUSIONS: Toxic materials within atheromatous lesions include both ceroid and even more cytotoxic lipidaceous materials. The cytotoxic effects of these plaque components may help explain the persistence of atherosclerotic lesions.

Chlamydia pneumoniae induces nitric oxide synthase and lipoxygenase-dependent production of reactive oxygen species in platelets. Effects on oxidation of low density lipoproteins.

There is increasing evidence that Chlamydia pneumoniae is linked to atherosclerosis and thrombosis. In this regard, we have recently shown that C. pneumoniae stimulates platelet aggregation and secretion, which may play an important role in the progress of atherosclerosis and in thrombotic vascular occlusion. The aims of the present study were to investigate the effects of C. pneumoniae on platelet-mediated formation of reactive oxygen species (ROS) and oxidation of low-density lipoprotein (LDL) in vitro. ROS production was registered as changes in 2',7'-dichlorofluorescin- fluorescence in platelets with flow cytometry. LDL-oxidation was determined by measuring thiobarbituric acid reactive substances (TBARs). We found that C. pneumoniae stimulated platelet production of ROS. Polymyxin B treatment of C. pneumoniae, but not elevated temperature, abolished the stimulatory effects on platelet ROS-production, which suggests that chlamydial lipopolysaccharide has an important role. Inhibition of nitric oxide synthase with nitro-L-arginine, lipoxygenase with 5,8,11-eicosatriynoic acid and protein kinase C with GF 109203X significantly lowered the production of radicals. In contrast, inhibition of NADPH-oxidase with di-phenyleneiodonium (DPI) did not affect the C. pneumoniae induced ROS-production. These findings suggest that the activities of nitric oxide synthase and lipoxygenase are the sources for ROS and that the generation is dependent of the activity of protein kinase C. The C. pneumoniae-induced ROS-production in platelets was associated with an extensive oxidation of LDL, which was significantly higher compared to the effect obtained by separate exposure of LDL to C. pneumoniae or platelets. In conclusion, C. pneumoniae interaction with platelets leading to aggregation, ROS-production and oxidative damage on LDL, may play a crucial role in the development of atherosclerotic cardiovascular disease.