The 2012 dengue outbreak in Madeira: exploring the origins.

In 2012, Madeira reported its first major outbreak of dengue. To identify the origin of the imported dengue virus, we investigated the interconnectivity via air travel between dengue-endemic countries and Madeira, and compared available sequences against GenBank. There were 22,948 air travellers to Madeira in 2012, originating from twenty-nine dengue-endemic countries; 89.6% of these international travellers originated from Venezuela and Brazil. We developed an importation index that takes into account both travel volume and the extent of dengue incidence in the country of origin. Venezuela and Brazil had by far the highest importation indices compared with all other dengue-endemic countries. The importation index for Venezuela was twice as high as that for Brazil. When taking into account seasonality in the months preceding the onset of the Madeira outbreak, this index was even seven times higher for Venezuela than for Brazil during this time. Dengue sequencing shows that the virus responsible for the Madeira outbreak was most closely related to viruses circulating in Venezuela, Brazil and Columbia. Applying the importation index, Venezuela was identified as the most likely origin of importation of dengue virus via travellers to Madeira. We propose that the importation index is a new additional tool that can help to identify and anticipate the most probable country of origin for importation of dengue into currently non-endemic countries.

Serum cathepsin S is associated with serum C-reactive protein and interleukin-6 independently of obesity in elderly men.

OBJECTIVE: Cathepsin S has been suggested provide a mechanistic link between obesity and atherosclerosis, possibly mediated via adipose tissue-derived inflammation. Previous data have shown an association between circulating cathepsin S and inflammatory markers in the obese, but to date, community-based reports are lacking. Accordingly, we aimed to investigate the association between serum levels of cathepsin S and markers of cytokine-mediated inflammation in a community-based sample, with prespecified subgroup analyses in nonobese participants. METHODS: Serum cathepsin S, C-reactive protein (CRP), and IL-6 were measured in a community-based cohort of elderly men (Uppsala Longitudinal Study of Adult Men; mean age 71 years, n = 991). CRP and IL-6 were also measured at a reexamination after 7 yr. RESULTS: After adjustment for age, body mass index, fasting plasma glucose, diabetes treatment, systolic blood pressure, diastolic blood pressure, hypertension treatment, serum cholesterol, serum high-density lipoprotein cholesterol, prior cardiovascular disease, smoking, and leisure time physical activity, higher cathepsin S was associated with higher CRP (regression coefficient for 1 sd increase, 0.13; 95% confidence interval 0.07-0.19; P < 0.001) and higher serum IL-6 (regression coefficient for 1 sd increase, 0.08; 95% confidence interval 0.01-0.14; P = 0.02). These associations remained similar in normal-weight participants (body mass index <25 kg/m(2), n = 375). In longitudinal analyses, higher cathepsin S at baseline was associated with higher serum CRP and IL-6 after 7 yr. CONCLUSIONS: These results provide additional evidence for the interplay between cathepsin S and inflammatory activity and suggest that this association is present also in normal-weight individuals in the community.

Serum and dietary beta-carotene and alpha-tocopherol and incidence of type 2 diabetes mellitus in a community-based study of Swedish men: report from the Uppsala Longitudinal Study of Adult Men (ULSAM) study.

AIMS/HYPOTHESIS: To investigate the association of serum concentrations and dietary intake of beta-carotene and alpha-tocopherol with type 2 diabetes incidence. METHODS: Serum beta-carotene, alpha-tocopherol, lifestyle factors (BMI, physical activity and smoking) and metabolic factors (insulin sensitivity [homeostasis model assessment], acute insulin response and impaired fasting glucose) were analysed in 846 50-year-old non-diabetic Swedish men (participants in the Uppsala Longitudinal Study of Adult Men). Diabetes was identified in 245 participants at reinvestigations after 10, 20 and 27 years. At the 20 year reinvestigation, dietary intake of beta-carotene and alpha-tocopherol, insulin sensitivity (euglycaemic-hyperinsulinaemic clamp) and insulin secretion (early insulin response in OGTT) were determined. RESULTS: The highest tertile of serum beta-carotene at age 50 (>0.335 mumol/l) was associated with 59% lower risk of diabetes during follow-up compared with the lowest tertile (<0.210 mumol/l) after adjustment for lifestyle and metabolic factors (p < 0.01). The highest tertile of lipid-corrected serum alpha-tocopherol at age 50 (>3.67 mumol/mmol) was associated with 46% lower risk of diabetes compared with the lowest tertile (<3.25 mumol/mmol) independently of metabolic factors (p < 0.05). Moreover, lower serum beta-carotene and alpha-tocopherol concentrations were independently associated with impaired insulin sensitivity (p < 0.001), but not with early insulin response, in a subsample of non-diabetic individuals 20 years later. Dietary intake of beta-carotene and alpha-tocopherol independently predicted type 2 diabetes during 7 years of follow-up. CONCLUSIONS/INTERPRETATION: Serum concentrations and dietary intakes of beta-carotene and alpha-tocopherol independently predicted insulin resistance and type 2 diabetes incidence during 27 years of follow-up in a community-based study of men. This result supports the importance of impaired antioxidant status for the development of insulin resistance and type 2 diabetes.

A polymorphism in the cyclooxygenase 1 gene is associated with decreased inflammatory prostaglandin F2alpha formation and lower risk of cardiovascular disease.

This study investigates the impact of genetic variation in the cyclooxygenase-1 (COX-1) gene on formation of the vasoconstrictive, pro-inflammatory prostaglandin F(2)(alpha) (PGF(2)(alpha)) and development of cardiovascular disease (CVD). We determined COX-1 genotypes, PGF(2)(alpha) formation and CVD prevalence in a Swedish cohort of 809 men at age 77 years. Of these, 237 had a history of CVD according to the registry data. Four of nine COX-1 single nucleotide polymorphisms were associated with altered formation of PGF(2)(alpha) (P<0.05). Two COX-1 gene variants (rs10306135 and rs883484) remained significantly associated with altered PGF(2)(alpha) formation after adjusted significance level for multiple testing (alpha-level=0.0059). Furthermore, individuals homozygote for the variant allele rs10306135 had lower prevalence of CVD, compared to the common allele (0% versus 30%, P=0.0047). In conclusion, subjects homozygote for the variant allele of a COX-1 gene polymorphism represent a subpopulation of men with decreased PGF(2)(alpha) formation and lower prevalence of CVD.

Both cyclooxygenase- and cytokine-mediated inflammation are associated with carotid intima-media thickness.

BACKGROUND: Common carotid artery intima-media thickness (CCA-IMT) is a valid index of atherosclerosis, which is viewed as an inflammatory disease. It is unknown if various modes of inflammation (cyclooxygenase [COX]-mediated, cytokine-mediated), oxidative stress and anti-oxidants are independently related to CCA-IMT. METHODS AND RESULTS: We investigated cross-sectional relations between CCA-IMT measured by B-mode ultrasound and COX-mediated inflammation (as measured by 15-keto-dihydro-prostaglandin F(2alpha) [PGF(2alpha)], cytokine-mediated inflammation (interleukin-6 [IL-6], high sensitivity C-reactive protein [hsCRP] and serum amyloid A protein [SAA]), oxidative stress (8-iso-PGF(2alpha), an F(2)-isoprostane; a non-enzymatic, free radical-induced product of arachidonic acid), and tocopherols (anti-oxidants) in a small subset of a population-based sample of elderly men (n=234) stating no use of anti-inflammatory medications. In a backward-stepwise regression analysis of correlates of CCA-IMT (with PGF(2alpha), hsCRP, IL-6, SAA, F(2)-isoprostanes, tocopherols, diabetes, body mass index (BMI), beta-blocker, statin treatment, smoking, hypertension and cholesterol), PGF(2alpha), CRP, beta-blocker treatment, diabetes and BMI were independently associated with CCA-IMT. There were no associations between F(2)-isoprostanes or tocopherols and CCA-IMT in this study. CONCLUSION: This study suggests both COX- and cytokine-mediated inflammation to be independently associated with increased CCA-IMT, implying that there might be more than one mode of inflammation involved in atherogenesis.

Increased serum cystatin C is associated with increased mortality in elderly men.

Renal dysfunction measured by serum creatinine is associated with increased cardiovascular morbidity and mortality. Plasma cystatin C has been shown in several studies to be superior to plasma creatinine for the estimation of glomerular filtration rate (GFR). The aim of the present study was to investigate the relationship between cystatin C and mortality in elderly men. Serum cystatin C was analyzed by nephelometry in a group of 77-year-old men (n=792) and correlated cystatin C levels with mortality during a follow-up period of 1-4 years. The cystatin C values were significantly correlated with overall mortality (p=0.013). Mortality was three times higher in the highest cystatin C quintile in relation to the lowest quintile.

Active smoking and a history of smoking are associated with enhanced prostaglandin F(2alpha), interleukin-6 and F2-isoprostane formation in elderly men.

The underlying mechanisms by which smoking induces cardiovascular diseases are largely unknown. The effect of smoking status on the cyclooxygenase (COX)-mediated inflammatory indicator prostaglandin F(2alpha) (PGF(2alpha)) has never been studied. Associations of cytokines and antioxidants and smoking status, have shown conflicting results. Urinary 15-keto-dihydro-PGF(2alpha) (a major metabolite of PGF(2alpha)), serum interleukin-6 (IL-6) and high sensitivity C-reactive protein (hsCRP), serum amyloid protein A (SAA), urinary 8-iso-PGF(2alpha) (an F(2)-isoprostane, indicator of oxidative stress), and serum alpha-tocopherol were quantified in a population-based sample (n = 642) of 77-year old men without diabetes. Fifty-five men were current smokers and 391 former smokers. Inflammatory indicators were increased in current smokers (15-keto-dihydro-PGF(2alpha), P < 0.001; IL-6, P = 0.01) than non-smokers. 8-iso-PGF(2alpha) was increased (P < 0.01) and alpha-tocopherol reduced (P < 0.001) in current smokers. Further, former smokers had increased formation of 15-keto-dihydro-PGF(2alpha), IL-6 and 8-iso-PGF(2alpha) compared non-smokers. This is the first study to show that smokers have increased PGF(2alpha) formation, thus enhanced COX-mediated inflammation, in addition to elevated levels of cytokines and isoprostanes. Subclinical COX- and cytokine-mediated inflammation and oxidative stress are ongoing processes not only in active smokers but also in former smokers which may contribute to the accelerated atherosclerosis associated with smoking.

Cyclooxygenase-mediated prostaglandin F2alpha is decreased in an elderly population treated with low-dose aspirin.

Low-dose aspirin (acetylsalicylic acid) is used as prophylaxis against cardiovascular diseases. The effect of aspirin on inflammation and oxidative stress, processes known to be involved in cardiovascular diseases, are not fully known. The cyclooxygenase(COX)-mediated inflammatory indicator prostaglandin F2alpha (PGF2alpha) (15-keto-dihydro-PGF2alpha), cytokine-mediated inflammatory indicators (interleukin-6, high-sensitivity C-reactive protein, serum amyloid A protein), and oxidative stress indicators (8-iso-PGF2alpha, tocopherols) were quantified in men with daily 75 mg of aspirin (n=175) and control men (n=464), all of age 77, in a cross-sectional study. Men treated with aspirin had decreased levels of urinary 15-keto-dihydro-PGF2alpha than controls (P<0.01), independent of possible cardiovascular risk factors. Aspirin-treated men had increased levels of alpha-tocopherol than controls (P<0.05). This is the first study to indicate that low-dose aspirin treatment is associated with decreased levels of PGF2alpha. This observation suggests a possible COX-mediated anti-inflammatory effect of low-dose aspirin, which should be further confirmed by intervention studies.

F(2)-isoprostane and prostaglandin F(2 alpha)metabolite excretion rate and day to day variation in healthy humans.

Isoprostanes are mainly formed in vivo by a non-enzymatic free radical catalysed oxidation of arachidonic acid. Studies have indicated that a major isoprostane, 8-iso-PGF(2 alpha)in plasma and urine is a reliable biomarker of oxidative stress. Prostaglandins are formed by enzymatic oxidation of arachidonic acid catalysed by cyclooxygenase (COX). 15-Keto-dihydro-PGF(2 alpha), a major metabolite of prostaglandin F(2 alpha)in plasma, and also found in urine, is considered to be a useful biomarker of inflammation. To investigate the excretion pattern and day to day variation of 8-iso-PGF(2 alpha)and 15-keto-dihydro-PGF(2 alpha)in healthy individuals, morning urine samples were collected from 13 volunteers on 10 successive days. The samples were analysed for free 8-iso-PGF(2 alpha)and 15-keto-dihydro-PGF(2 alpha)by radioimmunoassay. The mean excretion rate of 8-iso-PGF(2 alpha)was 0.27+/-0.11 nmol/mmol creatinine (mean+/-SD, n=13) and the coefficient of variation was 42% during the 10 days. The mean excretion rate of 15-keto-dihydro-PGF(2 alpha)was 0.46+/-0.19 nmol/mmol creatinine, giving a coefficient of variation of 41%. The mean values of 8-iso-PGF(2 alpha)were significantly correlated with the mean values of 15-keto-dihydro-PGF(2 alpha)(r=0.68, P=0.01). In conclusion, day to day biological variation in urinary excretion rate of 8-iso-PGF(2 alpha)and 15-keto-dihydro-PGF(2 alpha)should be taken into account in evaluating a clinical study unless a large increase or decrease of these parameters has been obtained.

F2-isoprostane excretion rate and diurnal variation in human urine.

8-Iso-PGF2alpha is formed in vivo by non-enzymatic free radical catalysed oxidation of arachidonic acid. Urinary measurement of this compound has previously been shown to reflect the oxidative stress of the body in human and animal studies. To investigate the normal excretion rate and a possible diurnal variation of 8-iso-PGF2alpha excretion in humans urinary samples were collected from ten healthy volunteers of both sexes at different times during a day and as a 24-h urine sample. The samples were analyzed by a newly developed radioimmunoassay with a specific antibody against free 8-iso-PGF2alpha. There was no diurnal variation in the urinary levels of 8-iso-PGF2alpha during the day in this study. Neither was there any statistically significant difference between the 8-iso-PGF2alpha levels at any time of the day or in the morning urine samples compared to the 24-h urine samples. In conclusion, all urine samples collected at any time of the day, preferably a morning urine sample (representative urine from 6-8 hours), can thus be used to obtain a reliable and adequate value of the amount of the 8-iso-PGF2alpha excretion in urine in healthy individuals.