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Increased oxidative stress generated nucleoside damage seems to play a crucial role in bipolar disorder (BD) pathophysiology. It may contribute to accelerated ageing and reduced life expectancy in patients with BD.In the five-year prospective "Bipolar Illness Onset study", we investigated repeated measurements of oxidative stress generated RNA and DNA damage in 357 patients with newly diagnosed/first-episode BD (880 visits), 132 of their unaffected first-degree relatives (236 visits) and 198 healthy age- and sex-matched control persons with no personal or first-degree family history of affective disorder (432 visits). Amongst patients with BD, we further investigated associations of oxidative stress generated RNA- and DNA damage with affective phases and measures of illness load.Patients newly diagnosed with BD and their unaffected relatives had higher levels of oxidative stress generated RNA damage than healthy control individuals and these differences persisted over time, whereas DNA damage was less consistently elevated. Neither illness load nor affective phase impacted the levels in patients with BD.Our findings support elevated oxidative stress generated RNA damage being a trait phenomenon in BD as indicated by persistent increase in RNA damage over time in patients newly diagnosed with BD and in their unaffected first-degree relatives compared with healthy control individuals. We did not detect state alterations in levels of oxidative stress.

Oxidative stress generated nucleoside damage seems to represent key pathophysiological mechanisms of bipolar disorder (BD). Likewise, mood and activity are core features of BD and can be reliably monitored using smartphone-based applications. The aim was to investigate whether oxidative stress generated nucleoside damage could reflect psychopathology in BD using easily available and non-invasive patient-reported smartphone-based symptoms. We included 223 patients newly diagnosed with BD and employed linear mixed-effect regression models to associate baseline measurements of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo) levels with patient-reported smartphone measures of mood, activity, anxiety, stress and sleep duration monitored three days prior to and 30 days after the baseline visit in the longitudinal Bipolar Illness Onset Study. In patients newly diagnosed with BD higher 8-oxoGuo levels were inversely associated with the patient-reported activity level (B = 0.953, 95%CI = 0.909;0.99, p = 0.043) and positively associated with patient-reported anxiety (B = 1.104, 95%CI = 1.022;1.161, p=0.012), perceived stress (B = 1.092, 95%CI = 1.009;1.183, p = 0.014) and sleep duration (B = 1.000, 95%CI = 1.000;1.001, p = 0.001), respectively, in analyses, adjusted for sex and age. The associations between 8-oxoGuo levels and anxiety, perceived stress and sleep duration, respectively, withstood adjustment for sex, age, smoking, BMI and alcohol intake. No associations between 8-oxodG levels and patient-reported smartphone-based data were found and mood was not associated with 8-oxoGuo. Oxidative stress was associated with patient-reported smartphone-based data on activity, anxiety, stress and sleep duration pointing towards that oxidative stress generated nucleoside damage may reflect ongoing psychopathology in BD.

Nucleic acid damage from oxidative stress (NA-OXS) may be a molecular mechanism driving the severely increased morbidity and mortality from somatic causes in adults with psychiatric disorders.To systematically retrieve and analyze data on NA-OXS across the psychiatric disorder diagnostic spectrum.The PubMed, Embase, and PsycINFO databases were searched from inception to November 16, 2021. A hand search of reference lists of relevant articles was also performed.Key study inclusion criteria in this meta-analysis were as follows: adult human study population, measurement of any marker of DNA or RNA damage from oxidative stress, and either a (1) cross-sectional design comparing patients with psychiatric disorders (any diagnosis) with a control group or (2) prospective intervention. Two authors screened the studies, and 2 senior authors read the relevant articles in full and assessed them for eligibility.The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Two authors performed data extraction independently, and a senior coauthor was consulted in cases of disagreement. Data were synthesized with random-effects and multilevel meta-analyses.The predefined hypothesis was that individuals with psychiatric disorders have increased NA-OXS levels. The main outcome was the standardized mean differences (SMDs) among patients and controls in nucleic acid oxidation markers compared across diagnostic groups. Analyses were divided into combinations of biological matrices and nucleic acids.Eighty-two studies fulfilled the inclusion criteria, comprising 205 patient vs control group comparisons and a total of 10 151 patient and 10 532 control observations. Overall, the data showed that patients with psychiatric disorders had higher NA-OXS levels vs controls across matrices and molecules. Pooled effect sizes ranged from moderate for urinary DNA markers (SMD = 0.44 [95% CI, 0.20-0.68]; P .001) to very large for blood cell DNA markers (SMD = 1.12 [95% CI, 0.69-1.55; P .001). Higher NA-OXS levels were observed among patients with dementias followed by psychotic and bipolar disorders. Sensitivity analyses excluding low-quality studies did not materially alter the results. Intervention studies were few and too heterogenous for meaningful meta-analysis.The results of this meta-analysis suggest that there is an association with increased NA-OXS levels in individuals across the psychiatric disorder diagnostic spectrum. NA-OXS may play a role in the somatic morbidity and mortality observed among individuals with psychiatric disorders.

BACKGROUND: Alcohol use disorder (AUD) is a chronic, relapsing brain disorder that accounts for 5% of deaths annually, and there is an urgent need to develop new targets for therapeutic intervention. The glucagon-like peptide-1 receptor agonist exenatide reduces alcohol consumption in rodents and non-human primates, but its efficacy in patients with AUD is unknown.METHODS: In a randomized, double-blinded, placebo-controlled clinical trial, treatment-seeking AUD patients were assigned to receive exenatide (2 mg subcutaneously) or placebo once weekly for 26-weeks, in addition to standard cognitive-behavioral therapy. The primary outcome was reduction in number of heavy drinking days. A subgroup also completed fMRI and SPECT brain scans.RESULTS: A total of 127 patients were enrolled. Our data revealed that although exenatide did not significantly reduce the number of heavy drinking days compared to placebo, it significantly attenuated fMRI alcohol cue-reactivity in the ventral striatum and septal area, which are crucial brain areas for drug reward and addiction. In addition, the dopamine transporter availability was lower in the exenatide group compared to the placebo group. Exploratory analyses revealed that exenatide significantly reduced heavy drinking days and total alcohol intake in a subgroup of obese patients (BMI>30 kg/m2). Adverse events were mainly gastrointestinal.CONCLUSIONS: This first RCT on the effects of a GLP-1 receptor agonist in AUD provides new important knowledge on the effects of GLP-1 receptor agonists as a novel treatment target in addiction.TRIAL REGISTRATION: EudraCT: 2016-003343-11 and ClinicalTrials.gov: NCT03232112FUNDING. The Novavi Foundation; The Research Foundation, Mental Health Services, Capital Region of Denmark; The Research Foundation, Capital Region of Denmark; The Ivan Nielsen Foundation; The A.P. Moeller and wife Chastine Mc-Kinney Moellers Family Foundation; The Augustinus Foundation; The Woerzner Foundation; Grosserer L.F Foghts Foundation; The Hartmann Foundation; The Aase and Ejnar Danielsen Foundation; The P.A. Messerschmidt and wife foundation and The Lundbeck Foundation. The funding sources and the manufacturer of exenatide once weekly (Bydureon®, AstraZeneca), had no influence on the trial design or data analysis.

Enhanced oxidative stress-generated nucleoside damage may contribute to the increased cardiovascular disease mortality in patients with bipolar disorder (BD) but the association has never been investigated. We investigated the associations between oxidative stress-generated damage to DNA (8-oxodG) and RNA (8-oxoGuo), respectively, and three measures reflecting cardiovascular risk; namely, the Framingham 30-year risk score of cardiovascular diseases, the metabolic syndrome, and the insulin resistance index in 360 patients newly diagnosed with BD, 102 of their unaffected relatives (UR) and 197 healthy control individuals (HC). In sex- and age-adjusted models, the 30-year cardiovascular risk score increased by 20.8% (CI = 7.4–35.9%, p = 0.002) for every one nM/mM creatinine increase in 8-oxoGuo and by 15.6% (95% CI = 5.8–26.4%, p = 0.001) for every one nM/mM creatinine increase in 8-oxodG, respectively. Further, insulin resistance index increased by 24.1% (95% CI = 6.7–43%, p = 0.005) when 8-oxoGuo increased one nM/mM creatinine. The associations between cardiovascular measures and oxidative nucleoside damage were more pronounced in patients with BD compared with UR, and HC. Metabolic syndrome was not associated with nucleoside damage. Overall, higher oxidative stress-generated nucleoside damage was associated with a higher cardiovascular risk score and a higher degree of insulin resistance index, and having BD impacted the associations. Further, within patients, treatment with psychotropics seemed to enhance the associations between 30-year CVD risk score and insulin resistance index, respectively, and oxidatively stress-generated nucleoside damage. Our findings support enhanced oxidative stress-generated nucleoside damage as a putative pathophysiological mechanism that may mediate the higher cardiovascular risk observed in patients with BD already at the time of diagnosis.

Oxidatively generated DNA damage is of paramount importance in a wide range of physiological and pathophysiological processes. Urinary 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG) is often used as an outcome marker in studies on the role of oxidatively generated DNA damage, but its exact relation to intracellular damage levels and variations in DNA repair have been unclear. Using a new approach of quantitative kinetic modeling inspired by pharmacokinetics, we find evidence that in steady state - i.e. when systemic consequences of given change in damage or cellular removal rates have stabilized - the urinary excretion of 8-oxodG is closely correlated to rates of damage and intracellular 8-oxodG levels, but independent of the rate of cellular removal. Steady state was calculated to occur within approximately 12 h. A similar pattern was observed in a model of the corresponding RNA marker 8-oxo-7,8-dihydroguanosine (8-oxoGuo), but with steady-state occurring slower (up to 5 d). These data have significant implications for the planning of studies and interpretation of data involving urinary 8-oxodG/8-oxoGuo excretion as outcome.HighlightsThe kinetics of 8-oxodG/8-oxoGuo formation, removal and excretion were simulated

Aims To compare the hazard of all-cause, chronic obstructive pulmonary disease (COPD) and heart failure (HF) hospitalization in carvedilol vs. metoprolol/bisoprolol/nebivolol users with COPD and concurrent HF from 2009 to 2012, and to evaluate the use and persistence in treatment of these β-blockers, their impact on the risk of COPD-related hospitalization, and the factors important for their selection. Methods and results Cox and logistic regression were used for both unadjusted and adjusted analyses. Carvedilol users had a higher hazard of being hospitalized for HF compared with metoprolol/bisoprolol/nebivolol users in both the unadjusted [hazard ratio (HR) 1.74; 95% confidence interval (CI) 1.65-1.83] and adjusted (HR 1.61; 95% CI 1.52-1.70) analyses. No significant differences were found for all-cause and COPD hospitalization between the two groups. Carvedilol users had a significant lower restricted mean persistence time than metoprolol/bisoprolol/nebivolol users. Patients exposed to carvedilol had an odds ratio (OR) of 1.38 (95% CI 1.23-1.56) for being hospitalized due to COPD within 60 days after redeeming the first carvedilol prescription, which was similar to that observed in metoprolol/bisoprolol/nebivolol users (OR 1.37; 95% CI 1.27-1.48). Patients with concurrent chronic kidney disease had a higher probability of receiving carvedilol (OR 1.16; 95% CI 1.04-1.29). Conclusion Carvedilol prescription carried an increased hazard of HF hospitalization and lower restricted mean persistence time among patients with COPD and concurrent HF. Additionally, we found a widespread phenomenon of carvedilol prescription at variance with the European Society of Cardiology guidelines and potential for improving the proportion of patients treated with β-blockers.

To compare the hazard of all-cause, chronic obstructive pulmonary disease (COPD) and heart failure (HF) hospitalization in carvedilol vs. metoprolol/bisoprolol/nebivolol users with COPD and concurrent HF from 2009 to 2012, and to evaluate the use and persistence in treatment of these β-blockers, their impact on the risk of COPD-related hospitalization, and the factors important for their selection.Cox and logistic regression were used for both unadjusted and adjusted analyses. Carvedilol users had a higher hazard of being hospitalized for HF compared with metoprolol/bisoprolol/nebivolol users in both the unadjusted [hazard ratio (HR) 1.74; 95% confidence interval (CI) 1.65-1.83] and adjusted (HR 1.61; 95% CI 1.52-1.70) analyses. No significant differences were found for all-cause and COPD hospitalization between the two groups. Carvedilol users had a significant lower restricted mean persistence time than metoprolol/bisoprolol/nebivolol users. Patients exposed to carvedilol had an odds ratio (OR) of 1.38 (95% CI 1.23-1.56) for being hospitalized due to COPD within 60 days after redeeming the first carvedilol prescription, which was similar to that observed in metoprolol/bisoprolol/nebivolol users (OR 1.37; 95% CI 1.27-1.48). Patients with concurrent chronic kidney disease had a higher probability of receiving carvedilol (OR 1.16; 95% CI 1.04-1.29).Carvedilol prescription carried an increased hazard of HF hospitalization and lower restricted mean persistence time among patients with COPD and concurrent HF. Additionally, we found a widespread phenomenon of carvedilol prescription at variance with the European Society of Cardiology guidelines and potential for improving the proportion of patients treated with β-blockers.

Aims To compare the hazard of all-cause, chronic obstructive pulmonary disease (COPD) and heart failure (HF) hospitalization in carvedilol vs. metoprolol/bisoprolol/nebivolol users with COPD and concurrent HF from 2009 to 2012, and to evaluate the use and persistence in treatment of these β-blockers, their impact on the risk of COPD-related hospitalization, and the factors important for their selection. Methods and results Cox and logistic regression were used for both unadjusted and adjusted analyses. Carvedilol users had a higher hazard of being hospitalized for HF compared with metoprolol/bisoprolol/nebivolol users in both the unadjusted [hazard ratio (HR) 1.74; 95% confidence interval (CI) 1.65-1.83] and adjusted (HR 1.61; 95% CI 1.52-1.70) analyses. No significant differences were found for all-cause and COPD hospitalization between the two groups. Carvedilol users had a significant lower restricted mean persistence time than metoprolol/bisoprolol/nebivolol users. Patients exposed to carvedilol had an odds ratio (OR) of 1.38 (95% CI 1.23-1.56) for being hospitalized due to COPD within 60 days after redeeming the first carvedilol prescription, which was similar to that observed in metoprolol/bisoprolol/nebivolol users (OR 1.37; 95% CI 1.27-1.48). Patients with concurrent chronic kidney disease had a higher probability of receiving carvedilol (OR 1.16; 95% CI 1.04-1.29). Conclusion Carvedilol prescription carried an increased hazard of HF hospitalization and lower restricted mean persistence time among patients with COPD and concurrent HF. Additionally, we found a widespread phenomenon of carvedilol prescription at variance with the European Society of Cardiology guidelines and potential for improving the proportion of patients treated with β-blockers.

Leg cramps are common in patients with heart failure. Quinine is frequently prescribed in low doses to these patients, but safety of this practice is unknown. We studied the outcomes associated with use of quinine in a nationwide cohort of patients with heart failure.Through individual-level-linkage of Danish national registries, we identified patients discharged from first-time hospitalization for heart failure in 1997-2010. We estimated the risk of mortality associated with quinine treatment by time-dependent Poisson regression models.A total of 135 529 patients were included, with 14 510 patients (11%) using quinine at some point. During a median time of follow-up of 989 days (interquartile range 350-2004) 88 878 patients (66%) died. Patients receiving quinine had slightly increased mortality risk, adjusted incidence rate ratio (IRR) 1.04 (95% confidence interval [CI] 1.01 to 1.07). The risks differed according to concomitant β-blocker treatment. For patients treated with both quinine and β-blockers IRR was 1.15 (95% CI 1.09 to 1.21) vs. 0.99 (95% CI 0.96 to 1.03) for patients treated with quinine but not β-blockers. The risks were highest shortly after initiation of therapy: for the first 14 days of treatment IRR was 2.12 (95% CI 1.54 to 2.93) for patients in treatment with β-blockers and 1.17 (95% CI 0.86 to 1.59) for patients not treated with β-blockers.Use of quinine was common and associated with increased mortality in heart failure, especially if administered together with β-blockers and shortly after treatment initiation. Mechanisms underlying the findings remain to be established.

To compare survival on different beta-blockers in heart failure.We identified all Danish patients ≥35 years of age who were hospitalized with a first admission for heart failure and who initiated treatment with a beta-blocker within 60 days of discharge. The study period was 1995-2011. The main outcome was all-cause mortality and all-cause hospitalization. Cox proportional hazard models were used to compare survival. The study included 58 634 patients of whom 30.121 (51.4%) died and 46.990 (80.1%) were hospitalized during follow-up. The mean follow-up time was 4.1 years. In an unadjusted model carvedilol was associated with a lower mortality [hazard ratio (HR) 0.737, 0.714-0.761] compared with metoprolol (reference) while bisoprolol was not associated with an increased mortality (HR 1.020, 0.973-1.069). In a model adjusted for possible confounders and stratified according to beta-blocker dosages, patients that received high-dose carvedilol (≥50 mg daily) had a lower all-cause mortality risk (HR 0.873, 0.789-0.966) than patients receiving high-dose (≥200 mg daily) metoprolol (reference). High-dose bisoprolol (≥10 mg daily) was associated with a greater risk of death (HR 1.125, 1.004-1.261). High-dose carvedilol was associated with significantly lower all-cause hospitalization risk (HR 0.842, 0.774-0.915) than high-dose metoprolol (reference), while high-dose bisoprolol had insignificantly lower risk than high-dose metoprolol (HR 0.948, 0.850-1.057).Heart failure patients receiving high-dose carvedilol (≥50 mg daily) showed significantly lower all-cause mortality risk and hospitalization risk, compared with other beta-blockers.

Accumulating evidence supports the popular notion that psychological stress states may accelerate aging. Stress has been shown to influence cellular systems known to be involved in the aging process. Furthermore, stress is associated with an increased risk of various age-related medical disorders. These effects are likely mediated by the secretion of stress hormones. In this short review we focus on biochemical and epidemiological evidence for a link between stress and aging.

Inflammation and endothelial activation are associated with an increased risk of CVD and epidemiological evidence suggests an association between levels of markers of inflammation or endothelial activation and the intake of fruit. Also, vitamin E, a fat-soluble antioxidant, has anti-inflammatory properties. We performed a randomised 2 × 2 factorial, crossover trial to determine the effect of orange and blackcurrant juice (500 ml/d) and vitamin E (15 mg RRR-α-tocopherol/d) supplementation on markers of inflammation and endothelial activation in forty-eight patients with peripheral arterial disease. Patients were randomly allocated to two dietary supplements from the four possible combinations of juice and vitamin E: juice+vitamin E; juice+placebo; reference beverage (sugar drink)+vitamin E; and reference beverage+placebo. The supplementations were given for 28 d, separated by a 4-week wash-out period. Analysis of main effects showed that juice decreased C-reactive protein (CRP) by 11 % and fibrinogen by 3 % while the reference drink increased CRP by 13 % and fibrinogen by 2 % (P P

The medication history among hospitalized patients often relies on patients' self-reports due to insufficient communication between health care professionals. The aim of the present study was to estimate the reliability of patients' self-reported medication use. Five hundred patients admitted to an acute medical department at a Danish university hospital were interviewed on the day of admission about their recent medication use. Blood samples drawn immediately after admission were screened for contents of 5 drugs (digoxin, bendroflumethiazide, amlodipine, simvastatin, glimepiride), and the results were compared to the patients' self-reported medication history. Information on prescribed drugs dispensed from any Danish pharmacy was collected from nationwide real-time pharmacy records. The authors performed home visits in a subgroup of 115 patients 4 weeks after their discharge. Stored drugs were inspected, and patients were interviewed about their drug use. Additional blood samples were drawn for drug analysis. The median age of included patients was 72 years, and 298 patients (60%) were women. Patients reported use of 3 (median) prescription-only medications (range, 0-14) during the structured interview. The congruence between self-report and drug analysis was high for all 5 drugs measured (all kappa0.8). However, 9 patients (2%) reported use of drugs that were not detected in their blood samples. In 29 patients (6%), the blood samples contained drugs not reported during the structured interview, but 14 of these drugs were registered in either hospital files or pharmacy records. Overall, the sensitivity of information from hospital files, structured interviews, and pharmacy records in identifying drug users was 87% to 93%, with no significant differences between methods. In conclusion, patients' self-reports are reliable when estimating recent use of cardiovascular and antidiabetic drugs.

Associations between genotypes of phase 2 enzymes and cancer risk are extracted from epidemiological studies, namely case-control studies. Variant alleles in glutathione S-transferase (GST), UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), and N-acetyltransferase (NAT) have been used as molecular genetic biomarkers of risk. GSTM(my)1 has been associated with an increased risk of colorectal cancer, lung cancer, and bladder cancer and GSTP(pi)1 with prostate cancer. UGT1A1*28 and *37 are both associated with an increased risk of breast cancer as is SULT1A1*2. The presence of UGT1A1*28 results in an increased risk of ovarian cancer and NAT2 of colorectal and lung cancer. A high frequency of SULT1A1*1 has been identified in patients with breast cancer; the role in colorectal cancer is more controversial. This chapter discusses the balance between carcinogen activation and detoxification in relation to phase 2 enzymes.

Exclusively private companies do drug development. The State contributes with education of academics and basic research constituting the basis of half of the drugs developed by the private companies. The Danish private drug research amounts to six billion DKK per year, corresponding to the estimated price of the development of one new drug. The development shows a negative tendency. There are doubts about the scientific credibility, the number of new drugs is declining, drug development costs are rising, and the competitiveness in Europe is declining compared with the one of The United States. Continued improvement of Danish drug development can be achieved by stimulation of the public research related to drug development.

The aim of this study was to determine by multivariate analysis how alcohol and other factors affect the clinical course and outcome in patients with acetaminophen (paracetamol) poisoning. A total of 645 consecutive patients admitted from 1994 to 2000 with single-dose acetaminophen poisoning were studied, giving special attention to alcohol history, time between overdose and intravenous N-acetylcysteine (NAC) treatment ("time to NAC"), and other data available at the time of admittance. Up until 72 hours after ingestion, time to NAC was the single most important independent risk factor. With a time to NAC less than 12 hours, the mortality rate was 0.42% (95% CI, 0.05-2.7). When time to NAC exceeded 12, 24, and 48 hours, the mortality rate increased to 6.1%, 13%, and 19%, respectively. Chronic alcohol abuse was an independent risk factor of mortality (odds ratio [OR], 3.52; 95% CI, 1.78-6.97). Acute alcohol ingestion was an independent protective factor regarding mortality in alcoholic patients (OR, 0.08; 95% CI, 0.01-0.66) but not in nonalcoholic patients (OR, 0.21; 95% CI, 0.03-1.67). Patient age and quantity of acetaminophen were independent risk factors. In conclusion, time to NAC was confirmed as the major risk factor in acetaminophen-induced hepatotoxicity and mortality. Chronic alcohol abuse was an independent risk factor that could be counteracted by concomitant acute alcohol ingestion. We suggest that patients with chronic alcoholism and suspected acetaminophen poisoning due to an increased risk of developing hepatotoxicity should be treated with NAC regardless of risk estimation.

Restriction of energy intake (ER), without malnutrition of essential nutrients, has repeatedly been demonstrated to increase longevity in rodents. In the antioxidant theory of aging the lack of balance between the generation of free radicals and free radical scavenging was thought to be a main causal agent, in the aging process. From this point of view the antiaging effect induced by ER might be due to the lower rate of free-radical production and related damage induced by a lower metabolic rate. The antiaging effects of ER might also occur in humans. This study explored the effects of a 10-week moderately energy-restricted diet (80% of habitual) in 24 non-obese middle-aged men (16 ER subjects, 8 controls) on resting metabolic rate (RMR) and indicators of the primary antioxidant defense system, oxidative stress and genotoxicity. RMR decreased significantly in both groups, even when adjustments were made for the change in body composition. The increase in blood vitamin C concentration correlated with the increase in urinary 8-hydroxydeoxyguanosine (80HdG) excretion. The change in urinary 80HdG excretion also correlated with the change in RMR per kg fat-free mass. No differences between groups were found for changes in indicators of genotoxicity, erythrocyte catalase, glutathione peroxidase and superoxide dismutase activity and in plasma vitamin E, A or beta-carotene concentrations. We conclude that 10 weeks of moderate ER did not affect indicators of antioxidative capacity, oxidative stress and genotoxicity of humans. Since subjects were not in energy balance at the end of the study, no conclusions can be made with respect to long-term effects.

Reactive free oxygen radicals are formed in the reactions involved in normal cell metabolism. This formation is closely regulated e.g. by dietary antioxidants. Present knowledge suggests that an imbalance, with surplus of free radicals, can play a role in the pathogenesis of certain types of cancer, atherosclerosis, and cataract. A number of epidemiological studies have demonstrated a reduced risk of developing these diseases in persons who consume a diet with a high content of vegetables and fruit, which contains large quantities of the antioxidants: beta-carotene, vitamins C and E. Intervention studies, using supplements of these antioxidants, have so far not been able to show a beneficial effect. The apparently protective effect of fruit and vegetables may be due to other active ingredients. In Denmark the average intake of vegetables and fruit is low, and it is estimated that an increased consumption of these foods could reduce the occurrence of certain cancer types and atherosclerosis. In contrast, there is no evidence that antioxidant supplements would provide protection against disease, and their safety remains to be established.

Nitroglycerin and other organic nitrates are beneficial in ischaemic heart disease and myocardial infarction and as adjunctive therapy in congestive heart failure. The nitrates are inactive prodrugs, and their vascular effects depend on metabolic conversion to vasoactive intermediates like nitric oxide and/or nitrosothiols with subsequent stimulation of guanylate cyclase causing increased formation of cyclic GMP. The compounds relax vascular smooth muscle producing venous dilatation at low concentrations and at higher concentrations dilation of coronary arteries and collaterals and systemic arterial vessels. Nitrate tolerance is, however, a problem with continuous nitrate therapy. Tolerance is most likely to occur with frequent dosing or with the use of long-acting nitrates or transdermal applications resulting in constant plasma concentrations. Therapeutic strategies should be designed to provide a daily low-nitrate period or nitrate-free period to obviate the development of tolerance and thus maintain the antianginal effects.

Reduced glutathione (GSH) is the main intracellular non-protein thiol compound. GSH is important in a variety of reactions including reductive processes, protection of cells against oxidative stress, free oxygen species and other toxic compounds of endogenous and exogenous origin. In the cardiovascular field, thiol compounds may protect against ischaemia-reperfusion injuries, regulate enzyme activities and modify the function of organic nitrates and vascular tone. Metabolic manipulation with thiol compounds (i.e. by treatment with N-acetylcysteine or oxothiazolidine) may provide a safe method for protecting cells against ischaemia and may be a relevant supplement to current cardiovascular therapy.

Hepatic dysfunction is a frequent finding in sepsis and peritonitis. In the present study, hepatic function in experimental peritonitis in the rat was determined by measuring serum levels of bilirubin, alkaline phosphatase (ALP), glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT), together with antipyrine (AP) clearance as a determinant of microsomal function. Peritonitis was induced by intraperitoneal injection of 3 x 10(8) colony-forming units of E. coli together with either 1.0 ml bile or saline. E. coli + bile peritonitis rats had significantly elevated levels of bilirubin, ALP, GOT and GPT as compared with both controls and rats with peritonitis induced by E. coli alone. The derangements gradually increased with time over the 10-hour period studied. In contrast, no reduction of AP clearance was observed in the peritonitis models. On the contrary, AP clearance was enhanced at 10 hours after induction of peritonitis by E. coli alone. In conclusion, hepatic dysfunction as revealed by routine laboratory tests is seen early in experimental peritonitis in the rat, but this is not accompanied by a reduced AP clearance rate.

The activity of 3 enzymes related to the bioactivation of toxic compounds and the development of cancer--cytochrome P450 IA2, N-acetyl transferase (NAT), and xanthine oxidase (XO)--can be measured from the ratios of formed metabolites excreted into urine. In the 3 experiments that comprised this study, subjects received at least 1 cup of coffee 2- 6 hours before spot urine samples were taken. The subjects included 335 healthy male and female volunteers who provided information on tobacco, caffeine, and broccoli intake in the preceding 2 weeks, 23 healthy men who exercised 8 hours/day for 30 days, and 9 subjects whose diet included green beans and broccoli. As expected, the ratio reflecting P450 IA2 activity was 66% and 70% higher, respectively, in men and women who smoked at least 10 cigarettes/day compared to male and female nonsmokers. The XO ratio also was significantly increased in smokers. 30 days of vigorous physical exercise increased the P450 IA2 ratio by 50% and the XO ratio by over 100%. Broccoli induced a 19% increase in P450 IA2 activity, while pregnancy and oral contraceptive use reduced this ratio by 29% and 20%, respectively. Since these ratios appear to yield reliable indicators of enzyme activity, prospective studies of their association with cancer development are recommended.

During 1978-1987 the annual sale of analgetics increased by 28% to 164 millions defined daily doses (mDDD) per year. Paracetamol changed status to over-the-counter drug by 1.1.1984 as did combinations of acetylicsalicylic acid and codein 14.5.1984. The consumption of paracetamol increased rapidly to 47 mDDD/-year, the mortality steadily decreasing to 0.07 deaths/mDDD in 1986. The consumption of salicylics decreased from 113 to 94 mDDD, of which the salicylic/codein combination constituted an increasing fraction. The mortality of salicylics increased from 0.05 death/mDDD in 1983 to 0.27/mDDD in 1986. Opoids except dextropropoxyphene increased three times during the period, while the risk of fatal poisoning decreased from 10 to 5 deaths/mDDD. Dextropropoxyphene consumption was stable 1978-86 while mortality doubled from 59 to 121 per year. After a National Board of Health initiative, 66 dextropropoxyphene deaths were seen in 1987. Paracetamol mortality was 10 times lower than in England and Wales, where a dextropropoxyphene/paracetamole combination (not available in Denmark) was often involved. From a toxicological point of view over the counter status for combinations of strong and weak analgetics are not desirable.

The cancer-preventive effect of energy restriction in rodents has been related to a decrease in oxidative damage to DNA. We have investigated the effect of energy restriction on the rate of oxidative DNA modification estimated from the urinary excretion of the repair product, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), in healthy, normal weight men. Before and after 10 weeks on a diet containing 80 (n = 16) or 100% (n = 8) of the estimated weight-maintaining energy, resting metabolic rate (RMR) was measured and 24-h urine was collected for 8-oxodG determination by HPLC. During the study, the weight loss was 10 and 2.5% of the initial weight, mostly in terms of fat, and the RMR decreased by 13 and 8% in the energy-restricted and control groups, respectively. With the use of t tests there was no significant difference within or between groups with respect to 8-oxodG excretion. However, if RMR was included as a covariate in multifactorial ANOVA, an average relative 17% (2-31%; 95% confidence interval) increase in 8-oxodG excretion in the energy-restricted group was significantly different from the corresponding value of the control group (P0.02). In the energy-restricted group the change in 8-oxodG excretion was correlated closely with the decrease in RMR (r = 0.63; P = 0.013). In the present study, 20% energy restriction for 10 weeks did not reduce oxidative DNA damage; we question a beneficial effect on cancer risk in normal weight humans.(ABSTRACT TRUNCATED AT 250 WORDS)

Reactive oxygen species (ROS) are generated from incomplete reduction in the respiratory chain. On one hand they pose a serious threat of deleterious effects on important macromolecules, among which DNA is considered most important since it carries the genetic information and changes will be carried on to future generations, or will fundamentally change the behaviour of the cells. On the other hand, it is becoming evident that there are important changes in the cells in response to redox changes. This review summarises the genes, the intracellular signalling elements and molecules that presently are known to be regulated by oxidative stress. It is now clear that both oxidants and antioxidants can regulate a multitude of different cellular functions, signal transduction pathways and gene expression. However, the quantitative importance is unknown and as of yet there are no examples of regulation exclusively by oxidative stress. Also the response to oxidative stress is variable, can be up-regulation as well as down-regulation, and different responses to dose or magnitude of the oxidative stress can be demonstrated. The effect from supplementation with an antioxidant is difficult to predict, and ultimately must be assessed in clinical trials.

Based on recent reports concerning the efficacy of N-acetylcysteine (NAC) in paracetamol (acetaminophen) poisoning, guidelines for treatment and control of these patients are reviewed by a study group under the Danish Association for the Study of the Liver. It is recommended that NAC-treatment is initiated immediately after referral and continued for 36 hours in all cases. Further NAC-treatment should not be discontinued before a decrease in INR has been observed.

Depletion of intracellular sulfhydryl groups has been considered a main reason for the development of nitrate tolerance during sustained nitrate therapy. Although administration of N-acetyl-cysteine, a sulfhydryl donor, potentiates the acute hypotensive effect of nitroglycerin (NTG), its role in the reversal of nitrate tolerance is controversial. In the present study, we developed a conscious in vivo rat model to study nitrate tolerance and nitrate-thiol interactions. Tolerance to NTG, as assessed by the blood pressure reduction in response to i.v. NTG bolus doses, developed after 24 h of i.v. NTG infusion. After 3 and 5 days of 0.2 mg/h NTG i.v., the dose-response relations for NTG-induced reduction in blood pressure were shifted to 25-fold higher doses (P less than .01). Infusion of N-acetylcysteine (0.245, 1.225 and 6.125 mmol/kg/h for 4 h) and, to a lesser extent, equimolar doses of reduced glutathione, but not N-acetylserine, significantly potentiated the hypotensive effect of NTG, in a dose-dependent manner (P less than .05). However, complete reversal of tolerance was not achieved. This animal model of nitrate tolerance is suitable for further investigations of nitrate-thiol interactions and shares similarities with nitrate tolerance development in humans. The results suggest that sulfhydryl supplementation may enhance the hypotensive effect of NTG in a dose-dependent manner. This effect is more likely to be achieved with N-acetylcysteine than with glutathione and may be related to differences in membrane permeability.

Nitrate tolerance has been explained by 1) a direct loss of pharmacological effect due to reduced bioconversion and 2) an indirect effect due to activation of the renin/angiotensin system and counter-regulatory vasoconstriction. The sulfhydryl compound N-acetylcysteine (NAC) has been shown to attenuate and partly counteract tolerance to nitrates, and this effect has been attributed to a nitrate/sulfhydryl interaction and increased production of vasoactive intermediates. The effect of NAC on counter-regulatory mechanisms is, however, unknown. This study examined whether NAC modulates the function of the renin/angiotensin system in normal rats and in nitrate-tolerant healthy volunteers. Animal study: Conscious rats received NAC (5 mmol/kg/hr i.v., n = 8) or placebo (N-acetylserine, n = 8). Two hours of NAC infusion significantly reduced the pressor effect of angiotensin I (ANG I) by 39 +/- 14% (mean +/- SEM) and reduced angiotensin converting enzyme activity by 31% in plasma (N-acetylserine: 74 +/- 9 nmol/min/mg, NAC: 51 +/- 7) and 43% in kidney (N-acetylserine: 0.9 +/- 0.3, NAC: 0.5 +/- 0.1 nmol/min/mg protein) (P.05). Clinical study: Isosorbide dinitrate (5 mg/hr) was infused into six male volunteers for 48 hr. NAC (2 g i.v. followed by 5 mg/kg/hr) was co-infused from 24 to 48 hr. Plasma angiotensin II (ANG II) increased during the first 24 hr of isosorbide dinitrate infusion and decreased from 28 +/- 4 to 14 +/- 2 ng/l after 2 hr of NAC infusion (P.05). The results suggest that sulfhydryl supplementation modifies the function of the renin/angiotensin system in vivo, an effect probably mediated by inhibition of angiotensin converting enzyme activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Normal aerobic metabolism produces huge amounts of potentially dangerous oxidants, controlled by a variety of antioxidant systems. An imbalance between the generated and exogenously inflicted oxidants and the oxidant system is termed oxidative stress. Even without oxidative stress, i.e. under normal physiological conditions, the damage to vital cellular micromolecules, such as DNA, is extensive, amounting to hundreds of hits per cell per day. More than one hundred different oxidative modifications in DNA have been described. The hydroxylation of guanine in the 8-position is the most frequent and most mutagenic lesion described. The 8-hydroxylation of guanine leads to lack of base pairing specifically and misreading of the modified base and adjacent residues. The modifications to DNA are so frequent that extensive and specific repair is needed for survival. Indeed, multiple repair enzyme systems to mediate and remove/repair oxidative DNA modification are described. Within DNA, hot-spots of oxidative modification and subsequent mutation have been described, and some specificity appears as compared to other agents that can lead to modification of DNA, i.e. aflatoxin and benzo[a]pyrene. Numerous publications from epidemiology and intervention studies with antioxidants point at oxidative modification as an important factor in cancer development at certain sites. Yet, direct evidence linking oxidative DNA modification to cancer has not been published. With regard to antoxidant prevention of cancer no effective single substance has so far been identified.

Cimetidine 1000 mg/day and phenobarbital 100 mg/day were given to five healthy volunteers for 13 days in order to investigate the combined effect and time course of inhibition and induction on hepatic drug metabolism. The one-sample antipyrine saliva clearance (APC) and urinary metabolite profile were measured weekly, once before, two times during and four times after drug administration. On the second day of drug treatment APC was 0.7 fold and the formation clearance of the 3 oxidized metabolites 0.6 fold decreased owing to an early inhibition by cimetidine (p less than 0.05). After 8 days of concomitant drug administration, i.e. when the drug mediated inhibition and induction are supposed to be at maximum, mean APC was 0.85 times the initial value (p greater than 0.05), whereas the formation clearances of nor- and 3-hydroxymethylantipyrine were still significantly depressed. Four and 11 days after drug withdrawal, when phenobarbital, but not cimetidine could be demonstrated in plasma, APC was 1.2 times the initial value (p less than 0.05). The results suggest, that the respective effects of cimetidine and phenobarbital on antipyrine elimination are additive, when given concomitantly, but that cimetidine exerts a relatively greater inhibition in the phenobarbital induced state.