Fake views removal and popularity on YouTube.

This paper analyses how YouTube authenticates engagement metrics and, more specifically, how the platform corrects view counts by removing "fake views" (i.e., views considered artificial or illegitimate by the platform). Working with one and a half years of data extracted from a thousand French YouTube channels, we show the massive extent of the corrections done by YouTube, which concern the large majority of the channels and over 78% of the videos in our corpus. Our analysis shows that corrections are not done continuously as videos collect new views, but instead occur in batches, generally around 5 p.m. every day. More significantly, most corrections occur relatively late in the life of the videos, after they have reached most of their audience, and the delay in correction is not independent of the final popularity of videos: videos corrected later in their life are more popular on average than those corrected earlier. We discuss the probable causes of this phenomenon and its possible negative consequences on content diffusion. By inflating view counts, fake views could make videos appear more popular than they are and unwarrantedly encourage their recommendation, thus potentially altering the public debate on the platform. This could have implications on the spread of online misinformation, but their in-depth exploration requires first-hand information on view corrections, which YouTube does not provide through its API. This paper presents a series of experimental techniques to work around this limitation, offering a practical contribution to the study of online attention cycles (as described in the "Data and methods" section). At the same time, this paper is also a call for greater transparency by YouTube and other online platforms about information with crucial implications for the quality of online debate.

Adipocytokine plasma level changes in a 24-month dietary and physical activity randomised intervention trial in postmenopausal women.

BACKGROUND: Adipocytokines are signaling molecules secreted by adipose tissue contributing to the control of body fat, energy expenditure and secretion of insulin and cytokines. They have been related to the development of obesity, type-2 diabetes, cardiovascular diseases and cancer. Diet and physical activity (PA) may have beneficial effects on their level. We evaluated the effects of a 24-month dietary and/or PA intervention on plasma levels of adipocytokines as a secondary analysis in the DAMA (Diet, physical Activity and Mammography) trial. METHODS: The 234 study participants (healthy postmenopausal women with high breast density, 50-69 years, non-smokers, no hormone therapy) were randomised to four arms: (1) isocaloric dietary intervention mainly based on plant-foods; (2) moderate-intensity PA intervention with at least 1 h/week of supervised strenuous activity; (3) both interventions; (4) general recommendations on healthy dietary and PA patterns. Leptin, resistin and adiponectin were measured at baseline and at the end of the intervention. Analyses were performed using Tobit regression. RESULTS: After 24 months, women randomised to PA intervention (arms #2 + #3) showed significant lower level of leptin (37.5% lower) and resistin (65.6% lower) compared to the control group (arms #1 + #4). No significant differences emerged in adiponectin levels. No significant differences in leptin, resistin and adiponectin levels at follow-up emerged in women randomised to the dietary intervention (arms #1 + #3) in comparison with controls (arms #2 + #4). CONCLUSION: This study supports the effectiveness of PA, even at moderate intensity, in improving the leptin and resistin profile in postmenopausal women. TRIAL REGISTRATION NUMBER: ISRCTN28492718, date of trial registration 17/05/2012.

The DAMA25 Study: Feasibility of a Lifestyle Intervention Programme for Cancer Risk Reduction in Young Italian Women with Breast Cancer Family History.

BACKGROUND: Diet and physical activity (PA) can modulate sporadic and possibly familial breast cancer (BC) risk. The DAMA25 study is a single-arm 12-month intervention aimed to modify dietary and PA habits in healthy young Italian women with a positive BC family history, categorized as having intermediate or high genetic risk according to NICE (National Institute for Health and Cancer Excellence) guidelines. METHODS: Participants, aged 25-49 years, were asked to adopt a diet mainly based on plant-based foods and to increase moderate daily activities combined with 1 h/week of more intense activity. Cooking lessons, collective walks, educational sessions, brochures, booklets and online materials were implemented. Dietary, PA habits and anthropometry were collected at baseline and at the end of the intervention. Changes on dietary, lifestyle habits and anthropometry were evaluated by GLM adjusted for weight reduction counselling aimed to participant with a BMI ≥ 25, age and baseline values of each variable. RESULTS: Out of 237 eligible women 107 (45.2%) agreed to participate and among them 98 (91.6%) completed the intervention. The adherence rate of the intervention was 77.8%. We observed a reduction in red and processed meat (p < 0.0001) and cakes consumption (p < 0.0001). Consumption of whole grain bread (p < 0.001), leafy vegetables (p = 0.01) and olive oil (p = 0.04) increased. We observed an increase in moderate (p < 0.0001) and more intense (p < 0.0001) recreational activities, an average 1.4 kg weight loss (p = 0.005), a reduction of waist circumference (p < 0.001) and fat mass (p = 0.015). CONCLUSIONS: The DAMA25 study shows that it is feasible an intervention to improve in the short-term dietary and PA habits and anthropometry in women with high BC familial risk.

The rhythms of the night: increase in online night activity and emotional resilience during the spring 2020 Covid-19 lockdown.

CONTEXT: The lockdown orders established in multiple countries in response to the Covid-19 pandemic are arguably one of the most widespread and deepest shock experienced by societies in recent years. Studying their impact trough the lens of social media offers an unprecedented opportunity to understand the susceptibility and the resilience of human activity patterns to large-scale exogenous shocks. Firstly, we investigate the changes that this upheaval has caused in online activity in terms of time spent online, themes and emotion shared on the platforms, and rhythms of content consumption. Secondly, we examine the resilience of certain platform characteristics, such as the daily rhythms of emotion expression. DATA: Two independent datasets about the French cyberspace: a fine-grained temporal record of almost 100 thousand YouTube videos and a collection of 8 million Tweets between February 17 and April 14, 2020. FINDINGS: In both datasets we observe a reshaping of the circadian rhythms with an increase of night activity during the lockdown. The analysis of the videos and tweets published during lockdown shows a general decrease in emotional contents and a shift from themes like work and money to themes like death and safety. However, the daily patterns of emotions remain mostly unchanged, thereby suggesting that emotional cycles are resilient to exogenous shocks. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1140/epjds/s13688-021-00262-1.

Time Course and Determinants of Individual Motivation among Women Enrolled in a Diet and Physical Activity Primary Prevention Trial.

We studied the determinants of motivation among post-menopausal women enrolled in a two-year diet and physical activity primary prevention randomized trial. Participants were requested to grade the importance attached to changing their lifestyle, their confidence about being able to implement the change, and their willingness to be involved in studies focusing on lifestyle. We used multi-adjusted regression to investigate the association between individual characteristics, study arm, and individual motivation at study entry and end. Participants (n = 234) were highly motivated both at entry and throughout the study. Women with pre-existing healthier eating habits and lifestyles (e.g., high consumption of fruit and vegetables, low red meat consumption, and physically active) were more motivated at entry and over the course of the study. Women assigned to any intervention arm were more motivated than those in the control arm. These findings may help enhance adherence to recommendations and improve effectiveness of community-based health promotion campaigns.

Can Dietary and Physical Activity Modifications Reduce Breast Density in Postmenopausal Women? The DAMA Study, a Randomized Intervention Trial in Italy.

BACKGROUND: Few randomized trials have been carried out to evaluate the effect of lifestyle modifications on mammographic breast density (MBD). The randomized 2 × 2 factorial Diet, physical Activity and MAmmography trial aimed to evaluate whether MBD can be reduced in postmenopausal women with high baseline MBD by a 24-month dietary and/or physical activity (PA) interventions. METHODS: We randomized healthy postmenopausal women, attending the Florence (Italy) mammographic screening program, ages 50 to 69 years, nonsmokers, with MBD > 50% and no recent hormone therapy, to (i) a dietary intervention focused on plant foods, with a low glycemic load, low in saturated fats and alcohol; (ii) a PA intervention combining daily moderate intensity activities and one weekly supervised session of more strenuous activity; (iii) both interventions; (iv) general recommendations. We evaluated changes in MBD based on Volpara estimates comparing baseline and follow-up digital mammograms by an intention-to-treat-analysis. RESULTS: MBD measures were available for 226 participants. An interaction emerged between treatments and thus we run analyses by arms. A decrease in volumetric percent density emerged for women in the dietary intervention (ratio 0.91; 95% CI, 0.86-0.97; P = 0.002) and in the PA intervention arm (0.93; 95% CI, 0.87-0.98; P = 0.01) in comparison with controls. No clear effect emerged in the double intervention arm. CONCLUSIONS: This intervention trial suggests that a 24-month dietary or PA intervention may reduce MBD in postmenopausal women. IMPACT: A modification of dietary habits or an increase in PA in postmenopausal women may reduce MBD. Further studies are needed to confirm these findings for planning breast cancer preventive strategies.

Low back pain in healthy postmenopausal women and the effect of physical activity: A secondary analysis in a randomized trial.

Epidemiological studies on the prevalence of musculoskeletal pain have consistently shown that this is a relevant health problem, with non-specific low back pain (LBP) being the most commonly reported in adult females. Conflicting data on the association between LBP symptoms and physical activity (PA) have been reported. Here, we investigated the prevalence of LBP and the effect of a 24-month non-specific PA intervention on changes in LBP prevalence in a series of Italian healthy postmenopausal women. We performed a secondary analysis in the frame of the DAMA trial, a factorial randomized intervention trial aimed to evaluate the ability of a 24-month intervention, based on moderate-intensity PA, and/or dietary modification, in reducing mammographic breast density in healthy postmenopausal women. The PA intervention included at least 1 hour/day of moderate PA and a more strenuous weekly activity, collective walks and theoretical group sessions. A self-administered pain questionnaire was administered at baseline and at the end of the intervention. The questionnaire was specifically structured to investigate the occurrence of musculoskeletal pain, the body localization, intensity and duration of the pain. Two hundred and ten women (102 randomized to PA intervention, 108 not receiving the PA intervention) filled out the questionnaires. At baseline LBP was present in 32.9% of the participants. Among women randomized to the PA intervention, LBP prevalence at follow up (21.6%) was lower than at baseline (33.3%) (p = 0.02), while in women who did not receive the PA intervention the LBP prevalence at baseline and follow up were 32.4% and 25.9%, respectively (p = 0.30). Overall, there was no significant between-group effect of PA intervention on LBP. Further studies are needed to understand the role of non-specific PA intervention, aimed to improve overall fitness, on LBP prevalence.

The DAMA trial: a diet and physical activity intervention trial to reduce mammographic breast density in postmenopausal women in Tuscany, Italy. Study protocol and baseline characteristics.

UNLABELLED: Aims and background. High mammographic breast density (MBD) is an established risk factor for breast cancer (BC). The influence of diet and physical activity (PA) on MBD has long been investigated. In an observational study of a cohort in Florence, we observed inverse associations between consumption of vegetables and olive oil and moderate leisure-time PA and MBD, while high alcohol intake and high glycemic load diets were positively associated with MBD. We set out to investigate whether dietary and PA interventions were able to reduce MBD in postmenopausal women with high MBD (>50%). Methods and study design. The DAMA (Diet, physical Activity and MAmmography) trial, a factorial randomized trial involving healthy nonsmoking postmenopausal women not using hormone replacement therapy and having MBD >50%, is aimed at evaluating the ability of a 24-month intervention based on moderate-intensity PA and/or dietary modification focused on plant foods with a low glycemic load, low in saturated fats and alcohol, and rich in antioxidants and fiber, to reduce the percent MBD. Participants have been randomized to 1 of 4 study arms (diet, PA, diet + PA, control). Dietary and PA habits and anthropometry are collected at baseline and at the end of the intervention phase together with repeated blood and urine samples. The primary outcome of the study is the absolute change in percent MBD as assessed on baseline and follow-up digital mammograms performed in the framework of the local screening program. Results. Of 728 eligible women, 234 (32.1%) agreed to participate. We did not observe any difference across study arms in the baseline distribution of variables of interest related to diet and lifestyle. Conclusions. The DAMA trial may contribute to a better understanding of MBD determinants. This will provide insight into the pathogenesis of BC and may allow the development of strategies for primary prevention focused on high-MBD groups that are easily identifiable in large-scale BC screening programs. TRIAL REGISTRATION NUMBER: ISRCTN28492718.

Circulating progenitor cells and the elderly: a seven-year observational study.

Cardiovascular (CV) diseases and related complications are the main causes of morbidity and mortality in the elderly. CV progenitor cells, including CD34+ cells, play a role in delaying the progression of atherosclerosis. In the present study we observed 100 octogenarians for seven years, in order to address the question of whether CD34+ cell number is a predictor of longevity in selected survivors. We also checked for associations of cell expression of manganese superoxide dismutase (Mn-SOD), catalase (CAT), and glutathione peroxidase type-1 (GPx-1) antioxidative enzymes, with number of CD34+ progenitor cells and mortality. We found that in very old subjects the number of CD34+ cells at baseline were higher in subjects who reached older age at death or were still living at the end of observation period, with respect to subjects who died from all causes, including CV deaths. On the other hand, HDL-C plasma levels and, with the exception of diabetes, the classic CV risk factors (hypertension, smoking, hypercholesterolemia) showed a loss of their predictive power. A significant association between the redox system of CD34+ cells and mortality was also observed. These data suggest that, even in the elderly, CD34+ cells maintain their role in predicting mortality. CD34+ cells could thus be considered as a biomarker of longevity.

Effects of the angiotensin II receptor blocker losartan on the monocyte expression of biglycan in hypertensive patients.

1. Recently, we demonstrated that biglycan (BGN) is increased in circulating monocyte cells from hypertensive patients and that angiotensin (Ang) II is able to increase BGN expression. The present study was designed to investigate the effects of treatment with the angiotensin AT(1) receptor antagonist losartan on monocyte BGN mRNA and protein expression in essential hypertension. 2. One hundred and twenty-six newly diagnosed hypertensive patients without additional risk factors for atherosclerosis and cardiovascular disease were treated with 100 mg losartan once daily for 6 months. Biglycan mRNA and protein expression was determined in monocytes isolated from peripheral blood before (T(0)) and after (T(1)) therapy. Plasma levels of interleukin (IL)-6, tumour necrosis factor (TNF)-alpha and high sensitivity C-reactive protein (hs-CRP) were also determined. In addition, BGN mRNA and protein expression was determined after the ex vivo addition of 1 micromol/L AngII to monocytes isolated from 20 randomly selected hypertensive patients. 3. Biglycan mRNA and protein expression, blood pressure and plasma levels of fibrinogen, IL-6, TNF-alpha and CRP were significantly lower at T(1) than at T(0). Variations in BGN expression were associated with inflammatory markers, but not directly with blood pressure. In AngII-stimulated monocytes, BGN mRNA and protein expression was significantly lower at T(1) that at T(0). Moreover, mean BGN mRNA expression in AngII-stimulated monocytes isolated from losartan-treated patients was similar to baseline expression in unstimulated monocytes from untreated patients. 4. The results of the present study show that losartan can reduce BGN expression in monocytes from hypertensive patients, without any linear association with blood pressure, suggesting that the effects of AngII on BGN expression in monocytes may be modulated, in part, by an AT(1) receptor blocker.

Platelet activating factor-acetylhydrolase (PAF-AH) activity and HDL levels, but not PAF-AH gene polymorphisms, are associated with successful aging in Sicilian octogenarians.

BACKGROUND AND AIMS: Aging is associated with an increased risk of developing atherosclerosis. Subjects over 80 years of age without cardiovascular disease provide a model to investigate the protective factors increasing their resistance to atherosclerotic disease. Platelet-activating factor acetylhydrolase (PAF-AH) is an enzyme associated with low density lipoprotein (LDL) and high density lipoprotein (HDL) inactivating platelet-activating factor (PAF) and preventing LDL oxidation by hydrolysis of oxidized phospholipids. The aim of the present study was to evaluate the contribution of the PAFAH gene Arg92His, Ile198Thr and Ala379Val polymorphisms to resistance toward developing cardiovascular events in healthy Sicilian octogenarians. METHODS: Distribution of PAF-AH genotypes and activity, and biochemical parameters, were compared between 100 octogenarians and 200 healthy adults. RESULTS: The individuals in the elderly group displayed significantly higher levels of HDL-C (p<0.001) and plasma (p<0.001) and HDL (p<0.001) PAF-AH activity. Analysis of PAFAH genotype distributions showed no significant differences between octogenarians and controls. No differences among PAF-AH genotypes with respect to plasma and HDL PAF-AH activity were found in either group. CONCLUSIONS: Our results provide no evidence of a significant association between the PAF-AH gene Arg92His, Ile198Thr and Ala379Val polymorphisms and successful aging in Sicilians. They also emphasize that, in these subjects, aging is characterized by increased levels of PAF-AH activity and HDL-C.

Tissue factor and monocyte chemoattractant protein-1 expression in hypertensive individuals with normal or increased carotid intima-media wall thickness.

BACKGROUND: People with hypertension display an inflammatory pattern that includes increased plasma concentrations of monocyte chemoattractant protein 1 (MCP-1) and C-reactive protein (CRP) and enhanced expression of tissue factor (TF) mRNA in blood monocytes. METHODS: In this study, we investigated the relationship between CRP concentrations and TF and MCP-1 mRNA expression in unstimulated and lipopolysaccharide (LPS)-stimulated monocytes isolated from hypertensives with or without an increase in carotid intima-media thickness (IMT). We also investigated the expression of TF and MCP-1 mRNA and MCP-1 protein after in vitro addition of CRP to monocytes. We measured CRP (by immunonephelometry) and monocyte expression of TF and MCP-1 (by real-time PCR) in 80 untreated hypertensive patients without clinical cardiovascular disease (CVD) or additional risk factors for CVD compared with 41 controls. Based on IMT measured by carotid Doppler ultrasonography, patients were classified into the categories of normal (< or =1 mm) or abnormal (>1 mm). TF and MCP-1 mRNA and MCP-1 protein (by Western blotting) were measured after in vitro addition of CRP to monocytes from 10 randomized controls as well as 10 hypertensives with IMT < or =1 mm and 10 with IMT >1 mm. RESULTS: CRP and TF and MCP-1 mRNA concentrations were significantly higher in IMT >1 mm hypertensives vs those with IMT < or =1 mm and controls. CRP had no effect on monocyte TF mRNA from either hypertensives or controls. CRP-stimulated monocytes from hypertensives, however, showed increased MCP-1 mRNA and protein expression compared with controls and LPS-stimulated cells. CONCLUSIONS: Our findings suggest that the inflammatory response of blood monocytes plays an important role in the development of atherosclerosis and hypertension.

Tissue factor expression and activity are not increased in peripheral monocytes isolated from uncomplicated hypertensive patients.

BACKGROUND: Systemic hypertension is one of the main risk factors for atherothrombosis. Tissue factor (TF) is found in the adventitia of blood vessels and in the lipid core of atherosclerotic plaques, and is specifically expressed on monocyte or macrophage cell membrane surfaces. TF plays a pivotal role in blood clotting physiology and is involved in pro-inflammatory action and atherosclerotic plaque destabilization. OBJECTIVE: In this study we investigated whether there is any relationship between TF messenger RNA expression and activity in blood monocytes isolated from hypertensive patients with clinical signs of atherosclerosis, uncomplicated hypertensive individuals and normotensive control subjects. METHODS: Eighty subjects (41 men and 39 women, mean age 41 +/- 12 years) with untreated essential hypertension and 41 control subjects matched for sex and age were enrolled in the study. Patients were classified according to whether they had a normal ( 1 mm, 39 patients) intima-media thickness (IMT). RESULTS: TF mRNA expression and activity in hypertensive individuals with no carotid atherosclerosis were no different from control subjects in unstimulated and stimulated monocytes. Abnormal IMT patients showed a higher TF mRNA expression compared with normal IMT hypertensive subjects (P < 0.001). CONCLUSIONS: We demonstrated that TF mRNA and activity levels in monocytes obtained from uncomplicated hypertensive individuals are comparable with those of normotensive subjects, whereas atherosclerotic hypertensive patients showed increased levels of these parameters.

Antioxidant effect of atorvastatin is independent of PON1 gene T(-107)C, Q192R and L55M polymorphisms in hypercholesterolaemic patients.

BACKGROUND: Serum paraoxonase (PON1), a high density lipoprotein (HDL)-bound antioxidant enzyme, plays a role in atherosclerosis. An increase in PON1 activity has been reported following statin treatment. OBJECTIVE: In the present study the following factors were evaluated: the influence of PON1 gene Q192R, L55M and T(-107)C polymorphisms on the response of LDL oxidisability and PON1 activity to atorvastatin treatment. RESEARCH DESIGN AND METHODS: 205 Sicilian subjects with primary hypercholesterolaemia (HCh) and 69 healthy subjects as controls were concurrently enrolled. Hypercholesterolaemic patients were randomly divided into two groups: an atorvastatin group (10 mg/day atorvastatin) and a placebo group. Lipid profile, markers of LDL resistance to in vitro oxidation (lag-phase, oxidation rate and thiobarbituric acid-reactive substances), vitamin E content in LDL, PON1 activity and genotypes in both HCh and control subjects were determined at baseline. The same parameters were measured again after 3 weeks of treatment in both the atorvastatin and placebo groups. RESULTS: HCh subjects showed significantly lower LDL resistance to oxidation, vitamin E content and PON1 activity levels than controls. A strong association was found among PON1 T(-107)C genotypes, LDL susceptibility to oxidation, vitamin E content and PON1 activity. After treatment, the atorvastatin group displayed a significant decrease in total cholesterol, LDL-cholesterol levels, and LDL susceptibility to oxidation, and an increase in vitamin E content and PON1 activity, compared with baseline values. Unlike PON1 activity levels, no difference among PON1 gene polymorphisms and reduction in markers of LDL oxidisability was observed. CONCLUSIONS: These results show, for the first time, that atorvastatin is able to improve the resistance to LDL oxidation independently of PON1 gene polymorphism.

Extracellular superoxide dismutase (EC-SOD) gene mutations screening in a sample of Mediterranean population.

The main role of superoxide dismutases (SODs) is to eliminate reactive oxygen species in cells and tissues. Extracellular SOD (EC-SOD/SOD3) is a major superoxide scavenger and it is located on cell surfaces and primarily in extracellular matrix, and binds heparan sulfates by its carboxyterminal portion. Human EC-SOD gene is located on chromosome 4 and comprises three exons and two introns. The SOD3 coding sequence is entirely located within exon 3 and has missense polymorphisms. The Arg213Gly mutation affects the function of the carboxyterminus and correlates with several diseases. In this work, we explored genetic variants within EC-SOD gene of subjects living in southern Italy. Four new variations were detected: one was silent mutation, while three were missense variations that give rise to amino acid substitutions at position 131 (F>C), 160 (V>L) and 202 (R>L) in the mature product. The Arg213Gly variant was not found. The missense mutations in the DNA of assayed 2400 chromosomes had frequencies of 5.34% for the F131C variation, 0.25% for the V160L variation and 0.84% for the R202L variation. The effect of these alterations on the metabolic activity and diseases remains to be further explained.

Platelet-activating factor acetylhydrolase is not associated with carotid intima-media thickness in hypercholesterolemic Sicilian individuals.

BACKGROUND: Atherosclerosis is a complex, chronic disease that usually arises from the converging action of several pathogenic processes, including hypertension, hyperlipidemia, obesity, and the accumulation of oxidized LDL. Platelet-activating factor acetylhydrolase (PAF-AH) is a LDL- and HDL-bound enzyme that hydrolyzes and inactivates PAF and prevents LDL-cholesterol oxidation, thus delaying the onset of atherosclerotic disease. METHODS: We evaluated the relationship between variants of the PAF-AH gene polymorphisms Arg92His, Ile198Thr, and Ala379Val and the presence of carotid atherosclerosis in 190 hypercholesterolemic Sicilian individuals. Carotid artery intima-media wall thickness (IMT) was measured as an indicator of early atherosclerotic disease. The participants were classified according to having normal (< or =1 mm) or abnormal (> or =1 mm) IMT and were also investigated for physical characteristics and biochemical indices, including PAF-AH activity. RESULTS: PAF-AH activity and LDL concentrations were significantly correlated in hypercholesterolemic patients, but plasma PAF-AH activity and HDL were not significantly correlated in either IMT group. No significant differences were detected among the PAF-AH gene polymorphisms in both groups after correction for age, sex, body mass index, plasma glucose and lipid concentrations, PAF-AH activity, blood pressure, and smoking habits. The analysis of PAF-AH genotype distribution showed no significant differences in percentage of 92, 198, and 379 genotypes in both IMT groups. CONCLUSION: Our data provided no evidence that PAF-AH polymorphisms influence PAF-AH activity and atherosclerosis in hypercholesterolemic Sicilian patients.

Association between serum paraoxonase (PON1) gene promoter T(-107)C polymorphism, PON1 activity and HDL levels in healthy Sicilian octogenarians.

Age is associated with an enhanced low density lipoprotein (LDL) oxidation and atherosclerosis, thus, subjects over 80 years without cardiovascular disease provide a model to investigate the protective factors against atherosclerosis. Serum paraoxonase (PON1), an high density lipoprotein (HDL)-bound enzyme, prevents LDL oxidation. The aim of the present study was to evaluate the contribution of the PON1 promoter T(-107)C and coding region Gln192Arg (Q192R) and Leu55Met (L55M) polymorphisms to the resistance to develop cardiovascular events in Sicilian healthy octogenarians. Distribution of PON1 genotypes and activity, and biochemical parameters, were compared between 100 octogenarians and 200 adults. Individuals in the elderly group displayed significant higher levels of HDL-C (P < 0.001) and PON1 activity (P < 0.001). The analysis of PON1 genotypes distribution showed an higher percentage of (-107)CC among octogenarians compared with controls. A significant difference among T(-107)C genotypes respect to PON1 activity and HDL-C levels occurred in both groups. The CC genotype was associated with higher PON1 activity and HDL levels compared to the TT genotypes. In conclusion, our results provide a strong evidence that in healthy Sicilians ageing may be characterized by a low frequency of PON1 (-107)T 'risk' allele and by an high frequency of favourable genotypes such as (-107)CC, influencing PON1 activity and HDL-C levels.

The paraoxonase promoter polymorphism (-107)T>C is not associated with carotid intima-media thickness in Sicilian hypercholesterolemic patients.

BACKGROUND AND OBJECTIVES: Increased plasma low-density lipoprotein-cholesterol (LDL-C) levels in hypercholesterolemic subjects are associated with enhanced LDL oxidation that represents an additional risk for atherosclerotic disease. Human serum paraoxonase (PON1), a high-density lipoprotein (HDL) associated enzyme, has been shown to protect LDL from oxidation, thus playing an important role in reducing the risk of atherosclerosis. PON1 gene polymorphisms have been found to be associated with the variations in serum PON1 levels and activities, and with the risk for coronary artery disease (CAD). This study was performed to evaluate the contribution of the PON1 promoter (-107)T>C and the coding region Gln 192 Arg (Q192R) and Leu 55 Met (L55M) polymorphisms to the presence of carotid atherosclerosis in 208 Sicilian subjects with primary hypercholesterolemia. METHODS: Carotid artery intima-media wall thickness (IMT) was measured as an indicator of early atherosclerotic disease. The subjects were classified according to whether they have a normal (1 mm) IMT. Subjects were also investigated for physical and biochemical parameters, including PON1 activity. RESULTS: No significant differences were detected among the PON1 genotypes with respect to age, sex, BMI, plasma lipids, systolic blood pressure in both groups of patients. There were significant differences between PON1 genotypes with respect to PON1 activity. The 192QQ, 55MM and (-107)TT genotypes showed lower PON1 activity compared to the RR, LL and CC genotypes. The PON1 (-107)T>C genotype distribution in both IMT groups showed no significant differences in percentage of TT, CT and CC genotypes. Similar results were obtained analyzing the Q192R and L55M genotype frequencies. Stepwise forward logistic regression analysis confirmed the lack of association between PON1 genotypes and carotid abnormalities. CONCLUSIONS: In conclusion, our data provided no evidence of a significant association between either PON1 promoter (-107)T>C or coding region, Q192R and L55M, polymorphisms and early carotid atherosclerosis in Sicilian hypercholesterolemic subjects.

Effects of AT1 receptor antagonist losartan on sICAM-1 and TNF-alpha levels in uncomplicated hypertensive patients.

This study was designed to determine whether the levels of soluble intercellular adhesion molecule-1 (sICAM-1) and tumor necrosis factor-alpha (TNF-alpha) were elevated in subjects with uncomplicated hypertension who presented with no other risk factors or evidence of athero-sclerosis. The effects of administration of an angiotensin type-1 antagonist (losartan) on the serum concentrations of these molecules were also examined. Twenty hypertensive (HT) subjects (12 men and 8 women, mean age 49.1 +/-7.2 years) without other risk factors or cardiovascular disease received placebo for 4 weeks. The patients were then treated with losartan (50 mg/day) for 24 weeks. After 4, 12, and 24 weeks of losartan treatment, sICAM-1 and TNF-alpha levels were measured. The same parameters were measured in 20 normotensive control subjects (C), matched for sex and age. HT had sICAM-1 and TNF-alpha basal values higher than C (respectively 351.7 +/-97.4 vs 201.6 +/-32.3 ng/mL, p<0.001 and 31.8 +/-2.4 vs 15.3 +/-2.2 pg/mL, p<0.001). There was a positive correlation between sICAM-1 and TNF-alpha levels, but no correlation in HT between the average diastolic and systolic blood pressure (clinic and ambulatory monitoring) and the sICAM-1 or TNF-alpha levels was observed. Losartan treatment caused a significant decrease of sICAM-1 levels at the end of the first month of treatment (300.2 +/-64.4 ng/mL, p<0.05), but the values reverted to the basal levels at the following time points. No variation of TNF-alpha levels during losartan treatment was observed. These results show that patients with uncomplicated mild essential hypertension presented with high plasma ICAM-1 and TNF-alpha concentrations. Although all the patients were responsive to the antihypertensive treatment with losartan, their plasma concentrations of TNF-alpha were not modified, and sICAM-1 concentrations decreased only for a short period of time. This suggests that in uncomplicated hypertension other factors besides the blood pressure modulate the endothelial inflammation.

Identification of paraoxonase 3 gene (PON3) missense mutations in a population of southern Italy.

PON gene family includes at least three members termed PON1, PON2 and PON3, and it is mapped on human chromosome 7q21-q22. PON1 and PON3 gene products are constituents of high density lipoprotein (HDL) and have many enzymatic properties and antioxidant activity. PONs are proposed to participate in the prevention of low density lipoprotein (LDL) oxidation. PON1 and PON2 genes have missense polymorphisms, but, to date, no missense variants are reported in PON3 gene. In this work we explored the existence of genetic variants within the PON3 coding sequences. Five point mutations were identified by direct sequencing of genomic DNA derived from 250 randomly selected DNA samples of 1143 blood donors living in southern Italy. Three were silent mutations, while two were missense mutations that give rise to amino acid substitutions at positions 311 (S>T) and 324 (G>D). The missense variations in the DNA of the 1143 samples had frequencies of 0.22% (5 out of 2286 alleles) for the S311T mutation, and 0.57% (13 out of 2286 alleles) for the G324D mutation. The effect of these variants on the metabolic activity of paraoxonase 3 remains to be further evaluated.