ASCEND-Eye: Effects of Omega-3 Fatty Acids on Diabetic Retinopathy

PURPOSE

Preclinical studies support a protective role for omega-3 fatty acids (FAs) on diabetic retinopathy (DR), but these observations have not been confirmed in randomized trials. We present randomized evidence for the effects of omega-3 FAs on DR outcomes.

DESIGN

A substudy of the A Study of Cardiovascular Events iN Diabetes (ASCEND) double-blind, randomized, placebo-controlled trial of 1 g omega-3 fatty acids (containing 460 mg eicosapentaenoic acid and 380 mg docosahexaenoic acid) daily for the primary prevention of serious cardiovascular events, in 15 480 UK adults at least 40 years of age, with diabetes.

PARTICIPANTS

Fifteen thousand four hundred eighty adults at least 40 years of age from the United Kingdom with diabetes from the ASCEND cohort.

METHODS

Linkage to electronic National Health Service Diabetic Eye Screening Programme records in England and Wales and confirmation of participant-reported eye events via medical record review. Log-rank and stratified log-rank methods were used for intention-to-treat analyses of time until the main outcomes of interest.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was time to the first postrandomization recording of referable disease, a composite of referable retinopathy (R2 or R3a/s) or referable maculopathy (M1) based on the grading criteria defined by the United Kingdom National Screening Committee. Secondary and tertiary outcomes included the referable disease outcome stratified by the severity of DR at baseline, any progression in retinopathy grade, and incident diabetic maculopathy.

RESULTS

Linkage data were obtained for 7360 participants (48% of those who were randomized in ASCEND). During their mean follow-up of 6.5 years, 548 participants (14.8%) had a referable disease event in the omega-3 FAs group, compared with 513 participants (13.9%) in the placebo group (rate ratio, 1.07; 95% confidence interval, 0.95-1.20; P = 0.29). There were no statistically significant between-group differences in the proportion of events for either of the secondary or tertiary outcomes.

CONCLUSIONS

Representing the largest prospective test of its kind to date, these data exclude any clinically meaningful benefits of 1 g daily omega-3 FAs on DR.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Exploring the Impact of Copper Oxide Substitution on Structure, Morphology, Bioactivity, and Electrical Properties of 45S5 Bioglass®

In recent decades, the requirements for implantable medical devices have increased, but the risks of implant rejection still exist. These issues are primarily associated with poor osseointegration, leading to biofilm formation on the implant surface. This study focuses on addressing these issues by developing a biomaterial for implant coatings. 45S5 bioglass® has been widely used in tissue engineering due to its ability to form a hydroxyapatite layer, ensuring a strong bond between the hard tissue and the bioglass. In this context, 45S5 bioglasses®, modified by the incorporation of different amounts of copper oxide, from 0 to 8 mol%, were synthesized by the melt-quenching technique. The incorporation of Cu ions did not show a significant change in the glass structure. Since the bioglass exhibited the capacity for being polarized, thereby promoting the osseointegration effectiveness, the electrical properties of the prepared samples were studied using the impedance spectroscopy method, in the frequency range of 102-106 Hz and temperature range of 200-400 K. The effects of CuO on charge transport mobility were investigated. Additionally, the bioactivity of the modified bioglasses was evaluated through immersion tests in simulated body fluid. The results revealed the initiation of a Ca-P-rich layer formation on the surface within 24 h, indicating the potential of the bioglasses to enhance the bone regeneration process.

Influence of the Addition of Zinc, Strontium, or Magnesium Oxides to the Bioglass 45S5 Network on Electrical Behavior

45S5 Bioglass has been widely used in regenerative medicine due to its ability to dissolve when inserted into the body. Its typically amorphous structure allows for an ideal dissolution rate for the formation of the hydroxyapatite layer, which is important for the development of new bone. This bioactive capacity can also be controlled by adding other oxides (e.g., SrO, ZnO, and MgO) to the 45S5 Bioglass network or by storing electrical charge. Ions such as zinc, magnesium, and strontium allow for specific biological responses to be added, such as antibacterial action and the ability to increase the rate of osteoblast proliferation. The charge storage capacity allows for a higher rate of bioactivity to be achieved, allowing for faster attachment to the host bone, decreasing the patient's recovery time. Therefore, it is necessary to understand the variation in the structure of the bioglass with regard to the amount of non-bridging oxygens (NBOs), which is important for the bioactivity rate not to be compromised, and also its influence on the electrical behavior relevant to its potential as electrical charge storage. Thus, several bioactive glass compositions were synthesized based on the 45S5 Bioglass formulation with the addition of various concentrations (0.25, 0.5, 1, and 2, mol%) of zinc, strontium, or magnesium oxides. The influence of the insertion of these oxides on the network was evaluated by studying the amount of NBOs using Raman spectroscopy and their implication on the electrical behavior. Electrical characterization was performed in ac (alternating current) and dc (direct current) regimes.

ASCEND-Eye: Effects of Aspirin on Diabetic Retinopathy

PURPOSE

Preclinical studies support a protective role for aspirin in early diabetic retinopathy (DR), but the findings from randomized trials are limited. We present randomized evidence for the efficacy and safety of aspirin on DR outcomes.

DESIGN

A substudy of the A Study of Cardiovascular Events in Diabetes (ASCEND) double-masked, randomized, placebo-controlled trial of 100 mg aspirin daily for the primary prevention of serious cardiovascular events in people with diabetes.

PARTICIPANTS

Fifteen thousand four hundred eighty United Kingdom adults at least 40 years of age with diabetes.

METHODS

Linkage to electronic National Health Service Diabetic Eye Screening Programme records in England and Wales and confirmation of participant-reported eye events via medical record review were carried out. Log-rank methods were used for intention-to-treat analyses of time until the first primary efficacy and safety outcomes.

MAIN OUTCOME MEASURES

The primary efficacy end point was the first record of referable disease after randomization, a composite of referable retinopathy or referable maculopathy based on the grading criteria defined by the United Kingdom National Screening Committee. The primary safety outcome was the first sight-threatening eye bleed, defined as clinically significant bleeding in the eye that resulted in unresolved visual loss or required an urgent intervention such as laser photocoagulation, vitreoretinal surgery, intraocular injection, or a combination thereof.

RESULTS

Linkage data were obtained for 7360 participants (48% of those randomized in ASCEND). During the mean follow-up of 6.5 years, 539 participants (14.6%) experienced a referable disease event in the aspirin group, compared with 522 participants (14.2%) in the placebo group (rate ratio, 1.03; 95% confidence interval [CI], 0.91-1.16; P = 0.64). No statistically significant between-group difference was found in the proportions of sight-threatening eye bleed events (57 participants [0.7%] and 64 participants [0.8%], respectively; rate ratio, 0.89; 95% CI, 0.62-1.27).

DISCUSSION

These data exclude any clinically meaningful benefits of aspirin for DR, but give reassurance regarding the ophthalmologic safety of aspirin.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

ASCEND-Eye: Rationale, design and baseline characteristics for a sub-study of the ASCEND randomised trial, exploring the effects of aspirin and omega-3 fatty acids on diabetic retinopathy and age-related macular degeneration

Background

Aspirin and omega-3 fatty acids (FAs) have potential disease-modifying roles in diabetic retinopathy (DR) and age-related macular degeneration (AMD), but randomized evidence of these effects is limited. We present the rationale and baseline characteristics of ASCEND-Eye, a sub-study of the double-blind, 2x2 factorial design, randomized placebo-controlled ASCEND (A Study of Cardiovascular Events iN Diabetes) trial of 100 mg aspirin daily and, separately, 1g omega-3 FAs daily for the primary prevention of serious cardiovascular events, in 15,480 British adults, aged 40 years or older with diabetes.

Methods

Eye events will be derived from three sources: 1) participant follow-up questionnaires from ASCEND, 2) electronic NHS Diabetic Eye Screening Programme (DESP) data and 3) responses to the National Eye Institute's Visual Function Questionnaire-25 (NEI-VFQ-25) sent to a subset of participants after the main trial ended. Analytic cohorts and outcomes relevant to these data sources are described. The primary outcome is referable diabetic eye disease, a secondary outcome is incident AMD events.

Results

Participant-reported events were ascertained for the full cohort of randomized individuals who were followed up over 7.4 years in ASCEND (n = 15,480). Linked DESP data were available for 48% of those (n = 7360), and 57% completed the NEI-VFQ-25 (n = 8839). The baseline characteristics of these three cohorts are presented.

Discussion

Establishing the risks and benefits of drugs commonly taken by people with diabetes, the elderly, or both, and finding new treatments for DR and AMD is important. ASCEND-Eye provides the opportunity to evaluate the effect of aspirin and, separately, omega-3 FAs for both conditions.

Study registration

Eudract No. 2004-000991-15; Multicentre Research Ethics Committee Ref No. 03/8/087; ClinicalTrials.gov No. NCT00135226; ISRCTN No. ISRCTN60635500.

Antibacterial Biomaterial Based on Bioglass Modified with Copper for Implants Coating

Biofilm-related implant infections pose a substantial threat to patients, leading to inflammation in the surrounding tissue, and often resulting in implant loss and the necessity for additional surgeries. Overcoming this implantology challenge is crucial to ensure the success and durability of implants. This study shows the development of antibacterial materials for implant coatings by incorporating copper into 45S5 Bioglass^®. By combining the regenerative properties of Bioglass^® with the antimicrobial effects of copper, this material has the potential to prevent infections, enhance osseointegration and improve the long-term success of implants. Bioglasses modified with various concentrations of CuO (from 0 to 8 mol%) were prepared with the melt-quenching technique. Structural analysis using Raman and FTIR spectroscopies did not reveal significant alterations in the bioglasses structure with the addition of Cu. The antibacterial activity of the samples was assessed against Gram-positive and Gram-negative bacteria, and the results demonstrated significant inhibition of bacterial growth for the bioglass with 0.5 mol% of CuO. Cell viability studies indicated that the samples modified with up to 4 mol% of CuO maintained good cytocompatibility with the Saos-2 cell line at extract concentrations up to 25 mg/mL. Furthermore, the bioactivity assessment demonstrated the formation of a calcium phosphate (CaP)-rich layer on the surfaces of all bioglasses within 24 h. Our findings show that the inclusion of copper in the bioglass offers a significant enhancement in its potential as a coating material for implants, resulting in notable advancements in both antibacterial efficacy and osteointegration properties.

Barium Titanate/Gadolinium Ferrite: A New Material Composite to Store Energy

This work investigates the dielectric properties of barium titanate/gadolinium ferrite ceramic composites, with different concentrations of each material. Our objective was to increase the storage ability of this material, finding a compromise between high permittivity and low dielectric losses. A two-step sintering procedure was used in the preparation of the composites to attain the desired results. Their morphological, structural and electrical properties were tested using scanning electron microscopy, X-Ray powder diffraction and impedance spectroscopy, respectively. Dielectric characterizations were performed on the frequency band of 100 Hz-1 MHz and for different temperatures (180-380 K). The best compromise between barium titanate and gadolinium ferrite in the composition was calculated in order to obtain a potential material for electrical energy storage. The sample with 25% gadolinium ferrite presented the best results. The dielectric constant reached values of the order of 2000, at 1 kHz and 340 K. It was also important not to have very high losses, and this was confirmed by the calculated loss tangent.

Bioactive Glass Modified with Zirconium Incorporation for Dental Implant Applications: Fabrication, Structural, Electrical, and Biological Analysis

Implantology is crucial for restoring aesthetics and masticatory function in oral rehabilitation. Despite its advantages, certain issues, such as bacterial infection, may still arise that hinder osseointegration and result in implant rejection. This work aims to address these challenges by developing a biomaterial for dental implant coating based on 45S5 Bioglass^® modified by zirconium insertion. The structural characterization of the glasses, by XRD, showed that the introduction of zirconium in the Bioglass network at a concentration higher than 2 mol% promotes phase separation, with crystal phase formation. Impedance spectroscopy was used, in the frequency range of 10²-10⁶ Hz and the temperature range of 200-400 K, to investigate the electrical properties of these Bioglasses, due to their ability to store electrical charges and therefore enhance the osseointegration capacity. The electrical study showed that the presence of crystal phases, in the glass ceramic with 8 mol% of zirconium, led to a significant increase in conductivity. In terms of biological properties, the Bioglasses exhibited an antibacterial effect against Gram-positive and Gram-negative bacteria and did not show cytotoxicity for the Saos-2 cell line at extract concentrations up to 25 mg/mL. Furthermore, the results of the bioactivity test revealed that within 24 h, a CaP-rich layer began to form on the surface of all the samples. According to our results, the incorporation of 2 mol% of ZrO₂ into the Bioglass significantly improves its potential as a coating material for dental implants, enhancing both its antibacterial and osteointegration properties.

Weight loss in a cardiovascular trial population identifies people at future risk of dementia

Introduction

Populations at increased risk of dementia need to be identified for well-powered trials of preventive interventions. Weight loss, which often occurs in pre-clinical dementia, could identify a population at sufficiently high dementia risk.

Methods

In 12,975 survivors in the Heart Protection Study statin trial of people with, or at high risk of, cardiovascular disease, the association of weight change over 5 years during the trial with post-trial dementia recorded in electronic hospital admission and death records (n = 784) was assessed, after adjustment for age, sex, treatment allocation, and deprivation measures.

Results

Among the 60% without substantial weight gain (≤2 kg weight gain), each 1 kg weight loss was associated with a risk ratio for dementia of 1.04 (95% confidence interval, 1.02-1.07). Weight loss ≥4 kg and cognitive function below the mean identified participants aged ≥67 years with a 13% 10-year dementia risk.

Discussion

The combination of weight loss and high vascular risk identified individuals at high risk of dementia who could be recruited to dementia prevention trials.

Oxidized phospholipids on apolipoprotein B-100 versus plasminogen and risk of coronary heart disease in the PROCARDIS study

BACKGROUND AND AIMS

Oxidized phospholipids carried on the apolipoprotein B-100 (OxPL-apoB) component of Lp(a) are predictive of coronary heart disease (CHD), but the role of oxidized phospholipids carried on plasminogen (OxPL-PLG) is unknown. We examined the independent effects of OxPL-apoB and OxPL-PLG for risk of CHD before and after adjustment for Lp(a).

METHODS

Plasma levels of OxPL-apoB, OxPL-PLG, plasminogen and Lp(a) were measured in the PROCARDIS study of early-onset CHD (906 cases/858 controls). Multivariable logistic regression was used to estimate the odds ratios (OR) for each biomarker with CHD after adjustment for established risk factors.

RESULTS

Mean levels of OxPL-apoB were higher in cases than controls, but levels of OxPL-PLG and plasminogen were similar. For OxPL-apoB, individuals in the top vs bottom fifth had 2-fold higher age and sex-adjusted OR of CHD (OR = 2.61 [95%CI: 1.91, 3.55]), which were partially attenuated after adjustment for established risk factors. The findings for OxPL-apoB and CHD in PROCARDIS were comparable with those of a meta-analysis of all such studies. However, the associations of OxPL-apoB with CHD were fully attenuated by additional adjustment for Lp(a) (OR = 0.93 [0.54,1.60]). Neither OxPL-PLG nor plasminogen were associated with CHD. Overall, there were no differences in the predictive value for CHD of high vs normal levels (<20th or >80th percentile) of OxPL-apoB, OxPL-PLG, plasminogen or Lp(a) after stratifying for each other.

CONCLUSIONS

These results highlight the context-dependency of OxPL in plasma and suggest that their associated risk of CHD is chiefly mediated by their carriage on Lp(a).

Kefir milk consumption decreases sperm alterations due to the high-fat diet in adult male rats

Over the past decades, an increase of male infertility through the decrease of sperm count has been noted. It has been suggested that environmental factors and lifestyle could a negative impact over sperm quality. Among these factors, the consumption of foods high in fat, which leads to overweight and obesity, can negatively influence fertility. The present study was designed to highlight the protective effect of Kefir, natural probiotic, against the decline in sperm quality related to fat high diet. Thirty adult rats were divided into four groups: Control (1 ml/100 g of body weight (bw) of semi-shimmed cow milk), KM (1 ml/100 g bw of Kefir milk), HFD (1 ml/100 g bw of semi-shimmed cow milk + high-fat diet) and KM/HFD (1 ml/100 g bw Kefir milk + high-fat diet). After 60 days of treatment, sperm quality, biochemical assays of lipids profil, blood cell count and histological examination in testis were assessed. The results described an improved of sperm density (64.28 10⁶  ml vs 54.14 10⁶  ml), viability (70.50% vs 55.33%), mobility (65.40% vs 63.60%) and morphological abnormalities (52% vs 25%) in the KM/HFD group compared to HFD group. In the same group, the lipid profil (Triglycerides (128.39 mg/dl vs 102.85 mg/dl), C-LDL (13.65 mg/dl vs 15.32 mg/dl) and C-HDL (23.21 mg/dl vs 19.15 mg/dl)) was corrected compared to HFD group. The histological observation of testis revealed a normal spermatogenesis compared to seminiferous tubules of HFD group, which showed a serious disruption and damage of testicular epithelium exerted by the high-fat diet. These findings corroborated the previous beneficial effect of Kefir and brought new insights into its beneficial effect against deteriorated spermatogenesis in obese adult rats.

Genetic associations of adult height with risk of cardioembolic and other subtypes of ischemic stroke: A mendelian randomization study in multiple ancestries

BACKGROUND

Taller adult height is associated with lower risks of ischemic heart disease in mendelian randomization (MR) studies, but little is known about the causal relevance of height for different subtypes of ischemic stroke. The present study examined the causal relevance of height for different subtypes of ischemic stroke.

METHODS AND FINDINGS

Height-associated genetic variants (up to 2,337) from previous genome-wide association studies (GWASs) were used to construct genetic instruments in different ancestral populations. Two-sample MR approaches were used to examine the associations of genetically determined height with ischemic stroke and its subtypes (cardioembolic stroke, large-artery stroke, and small-vessel stroke) in multiple ancestries (the MEGASTROKE consortium, which included genome-wide studies of stroke and stroke subtypes: 60,341 ischemic stroke cases) supported by additional cases in individuals of white British ancestry (UK Biobank [UKB]: 4,055 cases) and Chinese ancestry (China Kadoorie Biobank [CKB]: 10,297 cases). The associations of genetically determined height with established cardiovascular and other risk factors were examined in 336,750 participants from UKB and 58,277 participants from CKB. In MEGASTROKE, genetically determined height was associated with a 4% lower risk (odds ratio [OR] 0.96; 95% confidence interval [CI] 0.94, 0.99; p = 0.007) of ischemic stroke per 1 standard deviation (SD) taller height, but this masked a much stronger positive association of height with cardioembolic stroke (13% higher risk, OR 1.13 [95% CI 1.07, 1.19], p < 0.001) and stronger inverse associations with large-artery stroke (11% lower risk, OR 0.89 [0.84, 0.95], p < 0.001) and small-vessel stroke (13% lower risk, OR 0.87 [0.83, 0.92], p < 0.001). The findings in both UKB and CKB were directionally concordant with those observed in MEGASTROKE, but did not reach statistical significance: For presumed cardioembolic stroke, the ORs were 1.08 (95% CI 0.86, 1.35; p = 0.53) in UKB and 1.20 (0.77, 1.85; p = 0.43) in CKB; for other subtypes of ischemic stroke in UKB, the OR was 0.97 (95% CI 0.90, 1.05; p = 0.49); and for other nonlacunar stroke and lacunar stroke in CKB, the ORs were 0.89 (0.80, 1.00; p = 0.06) and 0.99 (0.88, 1.12; p = 0.85), respectively. In addition, genetically determined height was also positively associated with atrial fibrillation (available only in UKB), and with lean body mass and lung function, and inversely associated with low-density lipoprotein (LDL) cholesterol in both British and Chinese ancestries. Limitations of this study include potential bias from assortative mating or pleiotropic effects of genetic variants and incomplete generalizability of genetic instruments to different populations.

CONCLUSIONS

The findings provide support for a causal association of taller adult height with higher risk of cardioembolic stroke and lower risk of other ischemic stroke subtypes in diverse ancestries. Further research is needed to understand the shared biological and physical pathways underlying the associations between height and stroke risks, which could identify potential targets for treatments to prevent stroke.

Extraction of Pectin from Orange Peel and Study of Its Protective Effect Against Loperamide-Induced Impaired Gastrointestinal Motor Functions and Oxidative Stress in Rats

Pectin is a polysaccharide attached to carbohydrates. These are substances exclusively of plant origin. The aim of the present study is to evaluate the laxative effects of orange peel pectin extract (OPPE) against constipation induced by loperamide (LOP) in rats. Rats were equally divided into six groups and treated daily 1 week as follows: Control, LOP (3 mg/kg, body weight [b.w.], Per Os [p.o.]), LOP+yohimbine (2 mg/kg, b.w., i.p.), and LOP+OPPE (6.25, 12.5, and 25 mg/kg, b.w., p.o.). At the end of the experiment, the effects of OPPE were assessed by fecal parameters (numbers, weight, and water content), gastrointestinal transit, gastric emptying, serum metabolic parameter changes, intestinal and colon mucosa oxidative stress, and the histological examination. The defecation test showed that administration of LOP (3 mg/kg, b.w., p.o.) leads to the production of remarkable constipation. Indeed, the number and water content of stools decreased (25.50 [n/24 h] and 29.86%) significantly (P < .05). Acute pretreatment with OPPE significantly and dose dependently accelerated the stool moistening and allowed an increase of stool weight (2.85, 3.61, 3.93 [g/24 h/rat]) as well as the frequency of defecation (47.36, 54.54, and 56.26 [n/24 h]). OPPE also significantly (P < .05) and dose dependently increased the intestinal motility (70.78%, 73.33%, and 75.01%) and gastric emptying. LOP-induced reduction (P < .05) of intestinal secretion was accompanied by a colonic and small bowel oxidative stress status and histological changes, which was attenuated by OPPE treatment. The findings of this study indicate that OPPE possesses an important role in the gastrointestinal motility regulation, and thus lend pharmacological credence to the suggested use of the natural pectin for the treatment, management, and/or control of constipation.

Effects of Within-Person Variability in Spot Urinary Sodium Measurements on Associations With Blood Pressure and Cardiovascular Disease

Randomized trials of salt restriction have consistently demonstrated that decreasing salt consumption lowers blood pressure, but results of observational studies of salt intake and cardiovascular disease have been conflicting. After excluding individuals with prevalent cardiovascular or kidney disease in the prospective UK Biobank study, we examined the within-person variability in spot urinary sodium excretion and its impact on associations with systolic blood pressure and risk of incident cardiovascular disease. Spearman correlation coefficients were used to assess within-person variability in spot urinary sodium, and associations between sodium and blood pressure were assessed using linear regression in participants with measurements at baseline (N=355 134) and after 9 years (N=33 915). Cox regression was used to assess associations with the risk of cardiovascular disease over the same follow-up period (N=5566 events). The within-person variability in urinary sodium was extreme, with a self-correlation coefficient of 0.35 over 4 years. Each 100 mmol/L higher usual urinary sodium was associated with 3.09 mm Hg higher systolic blood pressure (95% CI, 2.7–3.48) at baseline, but had no association at 9 years (0.97 [−0.44 to 2.37]). Likewise, there was no association between urinary sodium and risk of cardiovascular disease over the same follow-up period (hazard ratio, 1.05, [0.87–1.26]). While spot urinary sodium measurements were associated with immediate effects on blood pressure at baseline, the extreme within-person variability in urinary sodium precluded detection of associations with future blood pressure at resurvey or risk of cardiovascular disease. The limitations of observational studies, irrespective of study size, should be recognized when assessing public policy on salt restriction.

A Biomarker-based Biological Age in UK Biobank: Composition and Prediction of Mortality and Hospital Admissions

Background

Chronological age is the strongest risk factor for most chronic diseases. Developing a biomarker-based age and understanding its most important contributing biomarkers may shed light on the effects of age on later-life health and inform opportunities for disease prevention.

Methods

A subpopulation of 141 254 individuals healthy at baseline were studied, from among 480 019 UK Biobank participants aged 40–70 recruited in 2006–2010, and followed up for 6–12 years via linked death and secondary care records. Principal components of 72 biomarkers measured at baseline were characterized and used to construct sex-specific composite biomarker ages using the Klemera Doubal method, which derived a weighted sum of biomarker principal components based on their linear associations with chronological age. Biomarker importance in the biomarker ages was assessed by the proportion of the variation in the biomarker ages that each explained. The proportions of the overall biomarker and chronological age effects on mortality and age-related hospital admissions explained by the biomarker ages were compared using likelihoods in Cox proportional hazard models.

Results

Reduced lung function, kidney function, reaction time, insulin-like growth factor 1, hand grip strength, and higher blood pressure were key contributors to the derived biomarker age in both men and women. The biomarker ages accounted for >65% and >84% of the apparent effect of age on mortality and hospital admissions for the healthy and whole populations, respectively, and significantly improved prediction of mortality (p < .001) and hospital admissions (p < 1 × 10⁻¹⁰) over chronological age alone.

Conclusions

This study suggests that a broader, multisystem approach to research and prevention of diseases of aging warrants consideration.

Effects of within-person variability in spot urinary sodium measurements on the associations with blood pressure and risk of cardiovascular disease in 0.5 Million adults in UK Biobank

Background

Randomised control trials have demonstrated direct positive and causal associations of 24-hr measurements of urinary sodium excretion on blood pressure. However, prospective studies, which often used spot (not 24-hr) measurements of urinary sodium, have reported J-shaped associations with higher risks of cardiovascular disease (CVD) at sodium intake &lt;4 g/day. The reasons for the discrepant results are not fully understood, but have prompted some to question the World Health Organisation's recommendations to restrict sodium intake to &lt;2.3g/day.

Purpose

We examined the effects of within-person variability in spot urinary sodium (UNa) measurements on immediate and delayed associations of UNa with blood pressure at baseline and at resurvey, and with incident cardiovascular disease in the UK Biobank (UKB).

Methods

Baseline spot urine samples were measured in 502,619 adults at baseline and in 20,346 participants who were resurveyed at 4 years after baseline. Linear regression was used to assess associations of baseline UNa measurements with systolic blood pressure (SBP; mmHg) at baseline and at resurvey. Cox regression was used estimate the associations between baseline measures of UNa with incident CVD events (recorded from linkage with hospital records). All analyses were adjusted for confounders and corrected for regression dilution bias.

Results

After excluding participants with prevalent diseases, the primary analyses involved 386,060 adults who were followed-up for a median of 7.8 years, during which ∼13,000 CVD events occurred. Estimated mean (SD) urinary sodium excretion was 77.4 mmol/L (SD 44.4, IQR = 42.8–103.7 mmol/L), and mean SBP/DBP were 137.5/82.3 (SD 18.5/10.1) mmHg, respectively. Within-person variability in UNa was high, with a self-correlation of 0.35 at 4 years between measurements. After adjustment for confounders and correction for regression dilution bias, a 100 mmol/L higher UNa was associated with an immediate 3.2 mmHg higher SBP (95% confidence interval [CI]: 2.8–3.6) in cross-sectional analyses (Figure 1). However, the corresponding associations of baseline UNa with SBP at resurvey was completely attenuated (p=0.20). The predicted risk of CVD was 1.06 (95% CI 1.06–1.07, p&lt;0.001) for a 3.2 mmHg higher SBP, but the observed risk for a 100 mmol/L higher UNa was 0.95 (95% CI 0.82–1.10, p=0.47) (Figure 1).

Conclusions

While spot measurements of UNa were strongly associated with immediate effects on SBP, the magnitude of within-person variability in UNa precluded detection of associations with SBP several years after baseline or with risk of CVD. The extreme within-person variability in spot UNa may explain the discrepant results of the trials and observational studies of sodium and blood pressure.

Figure 1. Spot UNa with SBP and CVD in UK Biobank

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Core funding from the Medical Research Council-Population Health Research Unit, British Heart Foundation

P656Risk of major gastrointestinal bleed in relation to vascular disease risk in 0.5M UK Biobank participants

Background

Low-dose aspirin is of established benefit for secondary prevention of cardiovascular events but in primary prevention the benefit is finely balanced with the hazard of major bleeds, and in particular gastrointestinal (GI) bleeds.

Purpose

To investigate non-vascular, non-genetic risk factors for major GI bleeds and derive a score for GI bleed risk which may help identify who will receive most net benefit from aspirin.

Methods

In the UK Biobank prospective study of 0.5M participants aged 40–69 at recruitment, prior history of cardiovascular disease, bleeds and other medical conditions was ascertained from self-reported diagnoses and electronic heath records (EHR) prior to recruitment. Major GI bleed during 6 years of follow-up was defined based on coded diagnoses and duration of hospital stay. Non-vascular risk factors for bleed were identified from amongst 100 baseline and prior disease factors using a stepwise regression with adjustment for established vascular risk factors, aspirin and warfarin use. 10-way cross-validation was used when making risk scores.

Results

Among the primary prevention population without prior intracranial bleed, serious extracranial bleed or gastrointestinal ulcer in the 6 months prior to recruitment, 1682 (0.06%/y) participants had a major GI bleed (1006 upper GI, 676 lower GI) with a mean stay in hospital of 3.2 days. Antiplatelet use (in 11%) and anticoagulant use (in 1%), were associated with 1.5 and 4 fold risks of GI bleed, respectively. Stepwise regression identified a non-vascular risk score for major bleed with a 4-fold risk ratio across fifths (Figure). But the score was also associated with a 2-fold risk ratio for major vascular events.

Conclusions

Major GI bleeds cause substantial morbidity. A 4-fold difference in bleed risk across quintiles was distinguishable by a score based largely on EHR prior disease information and frailty measures. This score is applicable in other contexts and will be applied in the ASCEND randomised trial of daily aspirin to provide randomized evidence of the net benefit of aspirin in different risk categories. However, vascular risk factors predicted risk of GI bleeds, and non-vascular risk factors for GI bleed predicted risk of major vascular events; so the net benefit from aspirin may vary only modestly across categories by vascular and bleed risks.

Effect of Hypericum humifusum aqueous and methanolic leaf extracts on biochemical and histological parameters in adult rats

Hypericum genus is traditionally known for its medicinal use and its therapeutic and antioxidant effects. However, the toxic effect of this plant has not been much explored. Our study aimed at investigating the effect of Hypericum humifusum (Hh) leaf extracts on oxidative stress parameters in male rats. For it, we first focused on the phytochemical analysis of the aqueous and methanolic extracts of Hh leaves. Hence, Wistar rats were treated per gavage for 30 days and divided into Control (1 mL/rat, distilled water), A200 group (200 mg/kg body weight (bw) aqueous extract), A400 group (400 mg/kg bw aqueous extract), M10 group (10 mg/kg bw methanolic extract), M20 group (20 mg/kg bw methanolic extract). The phytochemical analysis revealed the presence of tannins, flavonoids, steroids, carbohydrates, and phenolic compounds. Biochemical and histological investigations were performed in plasma and liver tissue. Liver tissue homogenates were used for the measurement of malondialdehyde (MDA), catalase (CAT) and superoxide dismutase (SOD) levels. At the same time, alanine transaminase (ALT), aspartate transaminase (AST) and lactate dehydrogenase (LDH) were assayed in plasma samples. Histological study was also conducted in liver. We showed that Hh extracts reduced relative liver weight and increased ALT, AST, LDH activities in treated groups compared to control group. These results were associated with an increase of MDA levels and a decrease of antioxidant enzyme activities (CAT and SOD) in liver tissues of treated rats. Histology of liver demonstrated several alterations showing necrosis, altered hepatocytes and lymphocyte migration mainly in A200 group and dilated sinusoids, foamy appearance of hepatocytes and lymphocyte accumulation in the other treated groups. This original work indicated that chronic consumption of Hh leaf extracts has no antioxidant effect but instead it induces oxidative stress and enhances markers of cell damage which was confirmed by histological study of liver rats.

Chronic consumption of Hypericum humifusum leaf extracts impairs epididymis spermatozoa characters in association with oxidative stress in adult male Wistar rats

Recently, there has been increasing interest in Hypericum (Hypericaceae) genus. The first part of the present study focused on the phytochemical analysis of the methanolic and aqueous extracts of Hypericum humifusum leaves. The second part of the study investigated the effect of Hypericum humifusum leaf extracts on male reproductive parameters. 30 male rats were grouped into control (1mL/rat, distilled water), treated by 200mg/kg body weight (bw) aqueous extract (A200), 400mg/kg bw aqueous extract (A400), 10mg/kg bw methanolic extract (M10) and 20mg/kg bw methanolic extract (M20) groups. The phytochemical analysis revealed the presence of tannins, flavonoids, steroids, carbohydrates, and phenolic compounds. After thirty-day treatment, body and reproductive organs were weighed. Testes in all rat groups were processed for biochemical assays and histopathological examinations. Epididymis sperm analyses were also performed. Testicular tissue homogenate samples were used for Malondialdehyde (MDA), catalase and superoxide dismutase (SOD) measurements. We showed that Hh extracts induced a severe seminiferous tubular damage with an increase in the percentage of empty seminiferous tubules. Epididymis sperm analysis revealed a significant reduction in density and viability of sperm with alteration of spermatozoa morphology. Also, we found that Hh leaf extracts decreased plasma total cholesterol, HDL-cholesterol and triglycerides levels. These results were associated with an increase of MDA levels and a decrease of catalase and SOD activities in testis tissues. Our finding revealed that chronic consumption of Hh extracts induces disruption of normal spermatogenesis by alteration of sperm density, viability, and morphology. This action may be due to an inhibition of the antioxidant-defense system.

Kohonen's Map Approach for the Belief Mass Modeling

In the framework of the evidence theory, several approaches for estimating belief functions are proposed. However, they generally suffer from the problem of masses attribution in the case of compound hypotheses that lose much conceptual contribution of the theory. In this paper, an original method for estimating mass functions using Kohonen's map derived from the initial feature space and an initial classifier is proposed. Our approach allows a smart mass belief assignment, not only for simple hypotheses but also for disjunctions and conjunctions of hypotheses. Thus, it can model at the same time ignorance, imprecision, and paradox. The proposed method for a basic belief assignment (BBA) is of interest for solving estimation mass functions problems where a large quantity of multivariate data is available. Indeed, the use of Kohonen's map simplifies the process of assigning mass functions. The proposed method has been compared with the state-of-the-art BBA technique on benchmark database and applied on remote sensing data for image classification purpose. Experimentation shows that our approach gives similar or better results than other methods presented in the literature so far, with an ability to handle a large amount of data.

Crystal structure of octa-kis-(N,N-di-methyl-formamide-κO)europium(III) tetra-cosa-μ2-oxido-dodeca-oxido-μ12-phosphato-dodeca-molybdate(VI)

The asymmetric unit of the title compound consists of one [Eu(C₃H₇NO)₈]³⁺ complex cation and one α-Keggin-type [PMo₁₂O₄₀] polyanion. Cations and anions are linked through C—H⋯O hydrogen bonds.

In the title salt, [Eu(C₃H₇NO)₈][PMo₁₂O₄₀], the asymmetric unit comprises one α-Keggin-type [PMo₁₂O₄₀]³⁻ polyoxidometalate anion and one distorted dodeca­hedral [Eu(C₃H₇NO)₈]³⁺ complex cation. In the crystal, the isolated polyoxidometalate anions are packed into hexa­gonally arranged rows extending parallel to [001]. The complex cations are situated between the rows and are linked to the neighbouring anions through weak C—H⋯O hydrogen-bonding inter­actions, leading to the formation of a three-dimensional network structure.

Hexakis(dimethyl sulfoxide-κO)zincmer-aquatris(dimethyl sulfoxide-κO)(ethanol-κO)[octadecatungstodiphosphato(V)-κO]zincate(II)–dimethyl sulfoxide–ethanol–water (2/4/2/3)

In the title compound, [Zn(C2H6OS)6]2[Zn(α-P2W18O62)(C2H5OH)(C2H6OS)3(H2O)]·2C2H6OS·C2H5OH·1.5H2O, there are two types of ZnIIcomplex ions. In the [Zn(α-P2W18O62)(C2H5OH)(C2H6OS)3(H2O)]4−anion, the ZnIIcation is coordinated by a Wells–Dawson polyanion [α-P2W18O62]6−(POM)viaa terminal O atom, three dimethyl sulfoxide (DMSO) ligands, one ethanol ligand and one water ligand in a distorted octahedral geometry. The two independent [Zn(C2H6OS)6]2+cations exhibit similar distorted octahedral coordination spheres, and both ZnIIcations are coordinated by six DMSO ligands. The crystal packing is governed by extensive O—H...O hydrogen bonds and weak C—H...O hydrogen bonds, forming a three-dimensional supramolecular structure. The S atoms of some DMSO molecules are disordered over two positions with different site-occupancy ratios.

Reliability Estimation Measure: Generic Discounting Approach

In the belief function theory, several measures of uncertainty have been introduced. One of their possible use is unreliable source discounting before the fusion stage. Two different measures of uncertainty exist which are the intrinsic and extrinsic ones. The intrinsic measure makes it possible to assess the source's confusion whereas the extrinsic one measures the contradiction between sources. In this paper, we associate both measures in order to estimate the global reliability of a source. This method, named Generic Discounting Approach (GDA), is proposed in two different versions: Weighted GDA and Exponent GDA. Those reliability measures are integrated into a classifier. The method was tested, against to some pioneer approaches, on several UCI datasets as well as on an urban image classification problem and showed very encouraging results.

Evidence for overdispersion in the distribution of malaria parasites and leukocytes in thick blood smears

Background

Microscopic examination of stained thick blood smears (TBS) is the gold standard for routine malaria diagnosis. Parasites and leukocytes are counted in a predetermined number of high power fields (HPFs). Data on parasite and leukocyte counts per HPF are of broad scientific value. However, in published studies, most of the information on parasite density (PD) is presented as summary statistics (e.g. PD per microlitre, prevalence, absolute/assumed white blood cell counts), but original data sets are not readily available. Besides, the number of parasites and the number of leukocytes per HPF are assumed to be Poisson-distributed. However, count data rarely fit the restrictive assumptions of the Poisson distribution. The violation of these assumptions commonly results in overdispersion. The objectives of this paper are to investigate and handle overdispersion in field-collected data.

Methods

The data comprise the records of three TBSs of 12-month-old children from a field study of Plasmodium falciparum malaria in Tori Bossito, Benin. All HPFs were examined systemically by visually scanning the film horizontally from edge to edge. The numbers of parasites and leukocytes per HPF were recorded and formed the first dataset on parasite and leukocyte counts per HPF. The full dataset is published in this study. Two sources of overdispersion in data are investigated: latent heterogeneity and spatial dependence. Unobserved heterogeneity in data is accounted for by considering more flexible models that allow for overdispersion. Of particular interest were the negative binomial model (NB) and mixture models. The dependent structure in data was modelled with hidden Markov models (HMMs).

Results

The Poisson assumptions are inconsistent with parasite and leukocyte distributions per HPF. Among simple parametric models, the NB model is the closest to the unknown distribution that generates the data. On the basis of model selection criteria AIC and BIC, HMMs provided a better fit to data than mixtures. Ordinary pseudo-residuals confirmed the validity of HMMs.

Conclusion

Failure to take overdispersion into account in parasite and leukocyte counts may entail important misleading inferences when these data are related to other explanatory variables (malariometric or environmental). Its detection is therefore essential. In addition, an alternative PD estimation method that accounts for heterogeneity and spatial dependence should be seriously considered in epidemiological studies with field-collected parasite and leukocyte data.

Statistical properties of parasite density estimators in malaria

Malaria is a global health problem responsible for nearly one million deaths every year around 85% of which concern children younger than five years old in Sub-Saharan Africa. In addition, around 300 million clinical cases are declared every year. The level of infection, expressed as parasite density, is classically defined as the number of asexual parasites relative to a microliter of blood. Microscopy of Giemsa-stained thick blood films is the gold standard for parasite enumeration. Parasite density estimation methods usually involve threshold values; either the number of white blood cells counted or the number of high power fields read. However, the statistical properties of parasite density estimators generated by these methods have largely been overlooked. Here, we studied the statistical properties (mean error, coefficient of variation, false negative rates) of parasite density estimators of commonly used threshold-based counting techniques depending on variable threshold values. We also assessed the influence of the thresholds on the cost-effectiveness of parasite density estimation methods. In addition, we gave more insights on the behavior of measurement errors according to varying threshold values, and on what should be the optimal threshold values that minimize this variability.

Influence of garlic or its main active component diallyl disulfide on iron bioavailability and toxicity

Garlic is regularly consumed and is known to have diverse biologic activities, particularly due to its antioxidant properties. In this study, we hypothesized that crude garlic can prevent iron-mediated oxidative stress in a rat model of nutritional iron overload, and we used an in vitro model to confirm the results. For the in vivo studies, rats received a basal diet supplemented with or without carbonyl iron (3%) and were fed distilled water or garlic solution (1g/kg body weight) by gavage for 3 weeks. The presence of both garlic and iron led to a 2-fold increase in plasma iron and a 50% increase in liver iron as compared with iron alone. However, garlic did not offer any protection against iron-induced oxidative stress. Duodenal divalent metal transporter-1 mRNA expression was fully repressed by iron and by the combined treatments but was also reduced by garlic alone. To confirm these data, we tested the effect of diallyl disulfide, one of the active components in garlic, in vitro on polarized Caco-2 cells. A 24-hour treatment decreased iron uptake at the apical side of Caco-2 cells but increased the percentage of iron transfer at the basolateral side. This probably resulted from a modest induction of ferroportin mRNA and protein expression. These results suggest that garlic, when given in the presence of iron, enhances iron absorption by increasing ferroportin expression. The presence of garlic in the diet at the dose studied does not seem to protect against iron-mediated oxidative stress.

Chronic crude garlic-feeding modified adult male rat testicular markers: mechanisms of action

BACKGROUND

Garlic or Allium sativum (As) shows therapeutic effects such as reduction of blood pressure or hypercholesterolemia but side-effects on reproductive functions remain poorly investigated. Because of garlic's chemical complexity, the processing methods and yield in preparations differ in efficacy and safety. In this context, we clarify the mechanisms of action of crushed crude garlic on testicular markers.

METHODS

During one month of treatment, 24 male rats were fed 5%, 10% and 15% crude garlic.

RESULTS

We showed that crude garlic-feeding induced apoptosis in testicular germ cells (spermatocytes and spermatids). This cell death process was characterized by increased levels of active CASP3 but not CASP6. Expression of the caspase inhibitors BIRC3 and BIRC2 was increased at all doses of As while expression of XIAP and BIRC5 was unchanged. Moreover, expression of the IAP inhibitor DIABLO was increased at doses 10% and 15% of As. The germ cell death process induced by As might be related to a decrease in testosterone production because of the reduced expression of steroidogenic enzymes (Star, Cyp11a, Hsd3b5 and Hsd17b). Evaluation of Sertoli markers showed that TUBB3 and GSTA2 expression was unchanged. In contrast, AMH, RHOX5 and CDKN1B expression was decreased while GATA4 expression was increased.

CONCLUSION

In summary, we showed that feeding with crude garlic inhibited Leydig steroidogenic enzyme expression and Sertoli cell markers. These alterations might induce apoptosis in testicular germ cells.

Optimization and biochemical characterization of a bacteriocin from a newly isolated Bacillus subtilis strain 14B for biocontrol of Agrobacterium spp. strains

AIMS

The identification of a new compound active against Agrobacterium tumefaciens.

METHODS AND RESULTS

The culture conditions of a newly isolated Bacillus subtilis strain, designed 14B, were optimized, as a first step, to produce its bacteriocin (termed Bac 14B) for the biocontrol of Agrobacterium spp., the causal agents of the crown gall disease. Bac 14B was then partially purified and biochemically characterized. Bacillus subtilis 14B was observed to produce an antibacterial compound having a protinaceous nature. As estimated by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE), the semi-purified bacteriocin substance was found to be a monomeric protein with a molecular weight of 21 kDa. While the latter's antimicrobial activity was completely stable during exposure to a temperature range of up to 100 degrees C for 2 h, its initial activity was totally lost at 121 degrees C for 20 min. The maximum bacteriocin production (4096 AU ml(-1)) was recorded after 96 h-incubation in an optimized Luria Bertani medium supplemented with 10 g l(-1) glucose, 15 g l(-1) K(2)HPO(4) and 5 g l(-1) MgSO(4) 7H(2)O at 30 degrees C in a shaking flask culture. Interestingly, the B. subtilis 14B culture supernatant that contained the bacteriocin under study was proved efficient in reducing both the percentage of galled plants and the number of galls in tomato.

CONCLUSION

The findings revealed that B. subtilis 14B and its bacteriocin are efficient in reducing the percentage of infections in plants caused by Ag. tumefaciens.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results could be useful for the nurserymen who are particularly interested in the biocontrol of the crown gall disease.